3349 lines
100 KiB
C
3349 lines
100 KiB
C
/* fts1 has a design flaw which can lead to database corruption (see
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** below). It is recommended not to use it any longer, instead use
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** fts3 (or higher). If you believe that your use of fts1 is safe,
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** add -DSQLITE_ENABLE_BROKEN_FTS1=1 to your CFLAGS.
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*/
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#if (!defined(SQLITE_CORE) || defined(SQLITE_ENABLE_FTS1)) \
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&& !defined(SQLITE_ENABLE_BROKEN_FTS1)
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#error fts1 has a design flaw and has been deprecated.
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#endif
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/* The flaw is that fts1 uses the content table's unaliased rowid as
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** the unique docid. fts1 embeds the rowid in the index it builds,
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** and expects the rowid to not change. The SQLite VACUUM operation
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** will renumber such rowids, thereby breaking fts1. If you are using
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** fts1 in a system which has disabled VACUUM, then you can continue
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** to use it safely. Note that PRAGMA auto_vacuum does NOT disable
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** VACUUM, though systems using auto_vacuum are unlikely to invoke
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** VACUUM.
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**
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** fts1 should be safe even across VACUUM if you only insert documents
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** and never delete.
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*/
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/* The author disclaims copyright to this source code.
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*
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* This is an SQLite module implementing full-text search.
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*/
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/*
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** The code in this file is only compiled if:
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**
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** * The FTS1 module is being built as an extension
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** (in which case SQLITE_CORE is not defined), or
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**
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** * The FTS1 module is being built into the core of
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** SQLite (in which case SQLITE_ENABLE_FTS1 is defined).
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*/
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#if !defined(SQLITE_CORE) || defined(SQLITE_ENABLE_FTS1)
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#if defined(SQLITE_ENABLE_FTS1) && !defined(SQLITE_CORE)
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# define SQLITE_CORE 1
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#endif
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#include <assert.h>
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#include <stdlib.h>
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#include <stdio.h>
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#include <string.h>
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#include <ctype.h>
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#include "fts1.h"
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#include "fts1_hash.h"
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#include "fts1_tokenizer.h"
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#include "sqlite3.h"
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#include "sqlite3ext.h"
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SQLITE_EXTENSION_INIT1
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#if 0
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# define TRACE(A) printf A; fflush(stdout)
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#else
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# define TRACE(A)
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#endif
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/* utility functions */
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typedef struct StringBuffer {
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int len; /* length, not including null terminator */
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int alloced; /* Space allocated for s[] */
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char *s; /* Content of the string */
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} StringBuffer;
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static void initStringBuffer(StringBuffer *sb){
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sb->len = 0;
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sb->alloced = 100;
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sb->s = malloc(100);
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sb->s[0] = '\0';
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}
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static void nappend(StringBuffer *sb, const char *zFrom, int nFrom){
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if( sb->len + nFrom >= sb->alloced ){
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sb->alloced = sb->len + nFrom + 100;
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sb->s = realloc(sb->s, sb->alloced+1);
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if( sb->s==0 ){
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initStringBuffer(sb);
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return;
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}
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}
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memcpy(sb->s + sb->len, zFrom, nFrom);
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sb->len += nFrom;
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sb->s[sb->len] = 0;
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}
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static void append(StringBuffer *sb, const char *zFrom){
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nappend(sb, zFrom, strlen(zFrom));
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}
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/* We encode variable-length integers in little-endian order using seven bits
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* per byte as follows:
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**
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** KEY:
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** A = 0xxxxxxx 7 bits of data and one flag bit
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** B = 1xxxxxxx 7 bits of data and one flag bit
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**
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** 7 bits - A
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** 14 bits - BA
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** 21 bits - BBA
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** and so on.
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*/
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/* We may need up to VARINT_MAX bytes to store an encoded 64-bit integer. */
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#define VARINT_MAX 10
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/* Write a 64-bit variable-length integer to memory starting at p[0].
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* The length of data written will be between 1 and VARINT_MAX bytes.
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* The number of bytes written is returned. */
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static int putVarint(char *p, sqlite_int64 v){
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unsigned char *q = (unsigned char *) p;
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sqlite_uint64 vu = v;
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do{
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*q++ = (unsigned char) ((vu & 0x7f) | 0x80);
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vu >>= 7;
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}while( vu!=0 );
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q[-1] &= 0x7f; /* turn off high bit in final byte */
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assert( q - (unsigned char *)p <= VARINT_MAX );
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return (int) (q - (unsigned char *)p);
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}
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/* Read a 64-bit variable-length integer from memory starting at p[0].
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* Return the number of bytes read, or 0 on error.
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* The value is stored in *v. */
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static int getVarint(const char *p, sqlite_int64 *v){
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const unsigned char *q = (const unsigned char *) p;
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sqlite_uint64 x = 0, y = 1;
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while( (*q & 0x80) == 0x80 ){
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x += y * (*q++ & 0x7f);
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y <<= 7;
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if( q - (unsigned char *)p >= VARINT_MAX ){ /* bad data */
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assert( 0 );
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return 0;
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}
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}
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x += y * (*q++);
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*v = (sqlite_int64) x;
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return (int) (q - (unsigned char *)p);
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}
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static int getVarint32(const char *p, int *pi){
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sqlite_int64 i;
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int ret = getVarint(p, &i);
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*pi = (int) i;
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assert( *pi==i );
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return ret;
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}
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/*** Document lists ***
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*
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* A document list holds a sorted list of varint-encoded document IDs.
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*
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* A doclist with type DL_POSITIONS_OFFSETS is stored like this:
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*
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* array {
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* varint docid;
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* array {
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* varint position; (delta from previous position plus POS_BASE)
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* varint startOffset; (delta from previous startOffset)
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* varint endOffset; (delta from startOffset)
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* }
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* }
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*
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* Here, array { X } means zero or more occurrences of X, adjacent in memory.
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*
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* A position list may hold positions for text in multiple columns. A position
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* POS_COLUMN is followed by a varint containing the index of the column for
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* following positions in the list. Any positions appearing before any
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* occurrences of POS_COLUMN are for column 0.
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*
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* A doclist with type DL_POSITIONS is like the above, but holds only docids
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* and positions without offset information.
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*
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* A doclist with type DL_DOCIDS is like the above, but holds only docids
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* without positions or offset information.
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*
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* On disk, every document list has positions and offsets, so we don't bother
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* to serialize a doclist's type.
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*
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* We don't yet delta-encode document IDs; doing so will probably be a
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* modest win.
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*
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* NOTE(shess) I've thought of a slightly (1%) better offset encoding.
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* After the first offset, estimate the next offset by using the
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* current token position and the previous token position and offset,
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* offset to handle some variance. So the estimate would be
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* (iPosition*w->iStartOffset/w->iPosition-64), which is delta-encoded
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* as normal. Offsets more than 64 chars from the estimate are
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* encoded as the delta to the previous start offset + 128. An
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* additional tiny increment can be gained by using the end offset of
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* the previous token to make the estimate a tiny bit more precise.
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*/
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/* It is not safe to call isspace(), tolower(), or isalnum() on
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** hi-bit-set characters. This is the same solution used in the
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** tokenizer.
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*/
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/* TODO(shess) The snippet-generation code should be using the
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** tokenizer-generated tokens rather than doing its own local
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** tokenization.
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*/
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/* TODO(shess) Is __isascii() a portable version of (c&0x80)==0? */
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static int safe_isspace(char c){
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return (c&0x80)==0 ? isspace(c) : 0;
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}
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static int safe_tolower(char c){
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return (c&0x80)==0 ? tolower(c) : c;
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}
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static int safe_isalnum(char c){
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return (c&0x80)==0 ? isalnum(c) : 0;
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}
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typedef enum DocListType {
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DL_DOCIDS, /* docids only */
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DL_POSITIONS, /* docids + positions */
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DL_POSITIONS_OFFSETS /* docids + positions + offsets */
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} DocListType;
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/*
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** By default, only positions and not offsets are stored in the doclists.
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** To change this so that offsets are stored too, compile with
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**
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** -DDL_DEFAULT=DL_POSITIONS_OFFSETS
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**
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*/
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#ifndef DL_DEFAULT
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# define DL_DEFAULT DL_POSITIONS
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#endif
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typedef struct DocList {
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char *pData;
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int nData;
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DocListType iType;
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int iLastColumn; /* the last column written */
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int iLastPos; /* the last position written */
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int iLastOffset; /* the last start offset written */
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} DocList;
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enum {
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POS_END = 0, /* end of this position list */
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POS_COLUMN, /* followed by new column number */
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POS_BASE
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};
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/* Initialize a new DocList to hold the given data. */
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static void docListInit(DocList *d, DocListType iType,
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const char *pData, int nData){
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d->nData = nData;
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if( nData>0 ){
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d->pData = malloc(nData);
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memcpy(d->pData, pData, nData);
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} else {
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d->pData = NULL;
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}
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d->iType = iType;
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d->iLastColumn = 0;
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d->iLastPos = d->iLastOffset = 0;
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}
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/* Create a new dynamically-allocated DocList. */
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static DocList *docListNew(DocListType iType){
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DocList *d = (DocList *) malloc(sizeof(DocList));
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docListInit(d, iType, 0, 0);
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return d;
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}
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static void docListDestroy(DocList *d){
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free(d->pData);
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#ifndef NDEBUG
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memset(d, 0x55, sizeof(*d));
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#endif
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}
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static void docListDelete(DocList *d){
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docListDestroy(d);
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free(d);
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}
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static char *docListEnd(DocList *d){
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return d->pData + d->nData;
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}
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/* Append a varint to a DocList's data. */
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static void appendVarint(DocList *d, sqlite_int64 i){
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char c[VARINT_MAX];
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int n = putVarint(c, i);
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d->pData = realloc(d->pData, d->nData + n);
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memcpy(d->pData + d->nData, c, n);
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d->nData += n;
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}
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static void docListAddDocid(DocList *d, sqlite_int64 iDocid){
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appendVarint(d, iDocid);
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if( d->iType>=DL_POSITIONS ){
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appendVarint(d, POS_END); /* initially empty position list */
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d->iLastColumn = 0;
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d->iLastPos = d->iLastOffset = 0;
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}
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}
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/* helper function for docListAddPos and docListAddPosOffset */
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static void addPos(DocList *d, int iColumn, int iPos){
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assert( d->nData>0 );
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--d->nData; /* remove previous terminator */
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if( iColumn!=d->iLastColumn ){
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assert( iColumn>d->iLastColumn );
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appendVarint(d, POS_COLUMN);
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appendVarint(d, iColumn);
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d->iLastColumn = iColumn;
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d->iLastPos = d->iLastOffset = 0;
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}
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assert( iPos>=d->iLastPos );
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appendVarint(d, iPos-d->iLastPos+POS_BASE);
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d->iLastPos = iPos;
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}
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/* Add a position to the last position list in a doclist. */
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static void docListAddPos(DocList *d, int iColumn, int iPos){
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assert( d->iType==DL_POSITIONS );
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addPos(d, iColumn, iPos);
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appendVarint(d, POS_END); /* add new terminator */
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}
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|
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/*
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** Add a position and starting and ending offsets to a doclist.
|
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**
|
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** If the doclist is setup to handle only positions, then insert
|
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** the position only and ignore the offsets.
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*/
|
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static void docListAddPosOffset(
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DocList *d, /* Doclist under construction */
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int iColumn, /* Column the inserted term is part of */
|
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int iPos, /* Position of the inserted term */
|
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int iStartOffset, /* Starting offset of inserted term */
|
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int iEndOffset /* Ending offset of inserted term */
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){
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assert( d->iType>=DL_POSITIONS );
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addPos(d, iColumn, iPos);
|
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if( d->iType==DL_POSITIONS_OFFSETS ){
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assert( iStartOffset>=d->iLastOffset );
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appendVarint(d, iStartOffset-d->iLastOffset);
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d->iLastOffset = iStartOffset;
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assert( iEndOffset>=iStartOffset );
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appendVarint(d, iEndOffset-iStartOffset);
|
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}
|
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appendVarint(d, POS_END); /* add new terminator */
|
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}
|
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|
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/*
|
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** A DocListReader object is a cursor into a doclist. Initialize
|
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** the cursor to the beginning of the doclist by calling readerInit().
|
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** Then use routines
|
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**
|
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** peekDocid()
|
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** readDocid()
|
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** readPosition()
|
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** skipPositionList()
|
|
** and so forth...
|
|
**
|
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** to read information out of the doclist. When we reach the end
|
|
** of the doclist, atEnd() returns TRUE.
|
|
*/
|
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typedef struct DocListReader {
|
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DocList *pDoclist; /* The document list we are stepping through */
|
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char *p; /* Pointer to next unread byte in the doclist */
|
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int iLastColumn;
|
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int iLastPos; /* the last position read, or -1 when not in a position list */
|
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} DocListReader;
|
|
|
|
/*
|
|
** Initialize the DocListReader r to point to the beginning of pDoclist.
|
|
*/
|
|
static void readerInit(DocListReader *r, DocList *pDoclist){
|
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r->pDoclist = pDoclist;
|
|
if( pDoclist!=NULL ){
|
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r->p = pDoclist->pData;
|
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}
|
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r->iLastColumn = -1;
|
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r->iLastPos = -1;
|
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}
|
|
|
|
/*
|
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** Return TRUE if we have reached then end of pReader and there is
|
|
** nothing else left to read.
|
|
*/
|
|
static int atEnd(DocListReader *pReader){
|
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return pReader->pDoclist==0 || (pReader->p >= docListEnd(pReader->pDoclist));
|
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}
|
|
|
|
/* Peek at the next docid without advancing the read pointer.
|
|
*/
|
|
static sqlite_int64 peekDocid(DocListReader *pReader){
|
|
sqlite_int64 ret;
|
|
assert( !atEnd(pReader) );
|
|
assert( pReader->iLastPos==-1 );
|
|
getVarint(pReader->p, &ret);
|
|
return ret;
|
|
}
|
|
|
|
/* Read the next docid. See also nextDocid().
|
|
*/
|
|
static sqlite_int64 readDocid(DocListReader *pReader){
|
|
sqlite_int64 ret;
|
|
assert( !atEnd(pReader) );
|
|
assert( pReader->iLastPos==-1 );
|
|
pReader->p += getVarint(pReader->p, &ret);
|
|
if( pReader->pDoclist->iType>=DL_POSITIONS ){
|
|
pReader->iLastColumn = 0;
|
|
pReader->iLastPos = 0;
|
|
}
|
|
return ret;
|
|
}
|
|
|
|
/* Read the next position and column index from a position list.
|
|
* Returns the position, or -1 at the end of the list. */
|
|
static int readPosition(DocListReader *pReader, int *iColumn){
|
|
int i;
|
|
int iType = pReader->pDoclist->iType;
|
|
|
|
if( pReader->iLastPos==-1 ){
|
|
return -1;
|
|
}
|
|
assert( !atEnd(pReader) );
|
|
|
|
if( iType<DL_POSITIONS ){
|
|
return -1;
|
|
}
|
|
pReader->p += getVarint32(pReader->p, &i);
|
|
if( i==POS_END ){
|
|
pReader->iLastColumn = pReader->iLastPos = -1;
|
|
*iColumn = -1;
|
|
return -1;
|
|
}
|
|
if( i==POS_COLUMN ){
|
|
pReader->p += getVarint32(pReader->p, &pReader->iLastColumn);
|
|
pReader->iLastPos = 0;
|
|
pReader->p += getVarint32(pReader->p, &i);
|
|
assert( i>=POS_BASE );
|
|
}
|
|
pReader->iLastPos += ((int) i)-POS_BASE;
|
|
if( iType>=DL_POSITIONS_OFFSETS ){
|
|
/* Skip over offsets, ignoring them for now. */
|
|
int iStart, iEnd;
|
|
pReader->p += getVarint32(pReader->p, &iStart);
|
|
pReader->p += getVarint32(pReader->p, &iEnd);
|
|
}
|
|
*iColumn = pReader->iLastColumn;
|
|
return pReader->iLastPos;
|
|
}
|
|
|
|
/* Skip past the end of a position list. */
|
|
static void skipPositionList(DocListReader *pReader){
|
|
DocList *p = pReader->pDoclist;
|
|
if( p && p->iType>=DL_POSITIONS ){
|
|
int iColumn;
|
|
while( readPosition(pReader, &iColumn)!=-1 ){}
|
|
}
|
|
}
|
|
|
|
/* Skip over a docid, including its position list if the doclist has
|
|
* positions. */
|
|
static void skipDocument(DocListReader *pReader){
|
|
readDocid(pReader);
|
|
skipPositionList(pReader);
|
|
}
|
|
|
|
/* Skip past all docids which are less than [iDocid]. Returns 1 if a docid
|
|
* matching [iDocid] was found. */
|
|
static int skipToDocid(DocListReader *pReader, sqlite_int64 iDocid){
|
|
sqlite_int64 d = 0;
|
|
while( !atEnd(pReader) && (d=peekDocid(pReader))<iDocid ){
|
|
skipDocument(pReader);
|
|
}
|
|
return !atEnd(pReader) && d==iDocid;
|
|
}
|
|
|
|
/* Return the first document in a document list.
|
|
*/
|
|
static sqlite_int64 firstDocid(DocList *d){
|
|
DocListReader r;
|
|
readerInit(&r, d);
|
|
return readDocid(&r);
|
|
}
|
|
|
|
#ifdef SQLITE_DEBUG
|
|
/*
|
|
** This routine is used for debugging purpose only.
|
|
**
|
|
** Write the content of a doclist to standard output.
|
|
*/
|
|
static void printDoclist(DocList *p){
|
|
DocListReader r;
|
|
const char *zSep = "";
|
|
|
|
readerInit(&r, p);
|
|
while( !atEnd(&r) ){
|
|
sqlite_int64 docid = readDocid(&r);
|
|
if( docid==0 ){
|
|
skipPositionList(&r);
|
|
continue;
|
|
}
|
|
printf("%s%lld", zSep, docid);
|
|
zSep = ",";
|
|
if( p->iType>=DL_POSITIONS ){
|
|
int iPos, iCol;
|
|
const char *zDiv = "";
|
|
printf("(");
|
|
while( (iPos = readPosition(&r, &iCol))>=0 ){
|
|
printf("%s%d:%d", zDiv, iCol, iPos);
|
|
zDiv = ":";
|
|
}
|
|
printf(")");
|
|
}
|
|
}
|
|
printf("\n");
|
|
fflush(stdout);
|
|
}
|
|
#endif /* SQLITE_DEBUG */
|
|
|
|
/* Trim the given doclist to contain only positions in column
|
|
* [iRestrictColumn]. */
|
|
static void docListRestrictColumn(DocList *in, int iRestrictColumn){
|
|
DocListReader r;
|
|
DocList out;
|
|
|
|
assert( in->iType>=DL_POSITIONS );
|
|
readerInit(&r, in);
|
|
docListInit(&out, DL_POSITIONS, NULL, 0);
|
|
|
|
while( !atEnd(&r) ){
|
|
sqlite_int64 iDocid = readDocid(&r);
|
|
int iPos, iColumn;
|
|
|
|
docListAddDocid(&out, iDocid);
|
|
while( (iPos = readPosition(&r, &iColumn)) != -1 ){
|
|
if( iColumn==iRestrictColumn ){
|
|
docListAddPos(&out, iColumn, iPos);
|
|
}
|
|
}
|
|
}
|
|
|
|
docListDestroy(in);
|
|
*in = out;
|
|
}
|
|
|
|
/* Trim the given doclist by discarding any docids without any remaining
|
|
* positions. */
|
|
static void docListDiscardEmpty(DocList *in) {
|
|
DocListReader r;
|
|
DocList out;
|
|
|
|
/* TODO: It would be nice to implement this operation in place; that
|
|
* could save a significant amount of memory in queries with long doclists. */
|
|
assert( in->iType>=DL_POSITIONS );
|
|
readerInit(&r, in);
|
|
docListInit(&out, DL_POSITIONS, NULL, 0);
|
|
|
|
while( !atEnd(&r) ){
|
|
sqlite_int64 iDocid = readDocid(&r);
|
|
int match = 0;
|
|
int iPos, iColumn;
|
|
while( (iPos = readPosition(&r, &iColumn)) != -1 ){
|
|
if( !match ){
|
|
docListAddDocid(&out, iDocid);
|
|
match = 1;
|
|
}
|
|
docListAddPos(&out, iColumn, iPos);
|
|
}
|
|
}
|
|
|
|
docListDestroy(in);
|
|
*in = out;
|
|
}
|
|
|
|
/* Helper function for docListUpdate() and docListAccumulate().
|
|
** Splices a doclist element into the doclist represented by r,
|
|
** leaving r pointing after the newly spliced element.
|
|
*/
|
|
static void docListSpliceElement(DocListReader *r, sqlite_int64 iDocid,
|
|
const char *pSource, int nSource){
|
|
DocList *d = r->pDoclist;
|
|
char *pTarget;
|
|
int nTarget, found;
|
|
|
|
found = skipToDocid(r, iDocid);
|
|
|
|
/* Describe slice in d to place pSource/nSource. */
|
|
pTarget = r->p;
|
|
if( found ){
|
|
skipDocument(r);
|
|
nTarget = r->p-pTarget;
|
|
}else{
|
|
nTarget = 0;
|
|
}
|
|
|
|
/* The sense of the following is that there are three possibilities.
|
|
** If nTarget==nSource, we should not move any memory nor realloc.
|
|
** If nTarget>nSource, trim target and realloc.
|
|
** If nTarget<nSource, realloc then expand target.
|
|
*/
|
|
if( nTarget>nSource ){
|
|
memmove(pTarget+nSource, pTarget+nTarget, docListEnd(d)-(pTarget+nTarget));
|
|
}
|
|
if( nTarget!=nSource ){
|
|
int iDoclist = pTarget-d->pData;
|
|
d->pData = realloc(d->pData, d->nData+nSource-nTarget);
|
|
pTarget = d->pData+iDoclist;
|
|
}
|
|
if( nTarget<nSource ){
|
|
memmove(pTarget+nSource, pTarget+nTarget, docListEnd(d)-(pTarget+nTarget));
|
|
}
|
|
|
|
memcpy(pTarget, pSource, nSource);
|
|
d->nData += nSource-nTarget;
|
|
r->p = pTarget+nSource;
|
|
}
|
|
|
|
/* Insert/update pUpdate into the doclist. */
|
|
static void docListUpdate(DocList *d, DocList *pUpdate){
|
|
DocListReader reader;
|
|
|
|
assert( d!=NULL && pUpdate!=NULL );
|
|
assert( d->iType==pUpdate->iType);
|
|
|
|
readerInit(&reader, d);
|
|
docListSpliceElement(&reader, firstDocid(pUpdate),
|
|
pUpdate->pData, pUpdate->nData);
|
|
}
|
|
|
|
/* Propagate elements from pUpdate to pAcc, overwriting elements with
|
|
** matching docids.
|
|
*/
|
|
static void docListAccumulate(DocList *pAcc, DocList *pUpdate){
|
|
DocListReader accReader, updateReader;
|
|
|
|
/* Handle edge cases where one doclist is empty. */
|
|
assert( pAcc!=NULL );
|
|
if( pUpdate==NULL || pUpdate->nData==0 ) return;
|
|
if( pAcc->nData==0 ){
|
|
pAcc->pData = malloc(pUpdate->nData);
|
|
memcpy(pAcc->pData, pUpdate->pData, pUpdate->nData);
|
|
pAcc->nData = pUpdate->nData;
|
|
return;
|
|
}
|
|
|
|
readerInit(&accReader, pAcc);
|
|
readerInit(&updateReader, pUpdate);
|
|
|
|
while( !atEnd(&updateReader) ){
|
|
char *pSource = updateReader.p;
|
|
sqlite_int64 iDocid = readDocid(&updateReader);
|
|
skipPositionList(&updateReader);
|
|
docListSpliceElement(&accReader, iDocid, pSource, updateReader.p-pSource);
|
|
}
|
|
}
|
|
|
|
/*
|
|
** Read the next docid off of pIn. Return 0 if we reach the end.
|
|
*
|
|
* TODO: This assumes that docids are never 0, but they may actually be 0 since
|
|
* users can choose docids when inserting into a full-text table. Fix this.
|
|
*/
|
|
static sqlite_int64 nextDocid(DocListReader *pIn){
|
|
skipPositionList(pIn);
|
|
return atEnd(pIn) ? 0 : readDocid(pIn);
|
|
}
|
|
|
|
/*
|
|
** pLeft and pRight are two DocListReaders that are pointing to
|
|
** positions lists of the same document: iDocid.
|
|
**
|
|
** If there are no instances in pLeft or pRight where the position
|
|
** of pLeft is one less than the position of pRight, then this
|
|
** routine adds nothing to pOut.
|
|
**
|
|
** If there are one or more instances where positions from pLeft
|
|
** are exactly one less than positions from pRight, then add a new
|
|
** document record to pOut. If pOut wants to hold positions, then
|
|
** include the positions from pRight that are one more than a
|
|
** position in pLeft. In other words: pRight.iPos==pLeft.iPos+1.
|
|
**
|
|
** pLeft and pRight are left pointing at the next document record.
|
|
*/
|
|
static void mergePosList(
|
|
DocListReader *pLeft, /* Left position list */
|
|
DocListReader *pRight, /* Right position list */
|
|
sqlite_int64 iDocid, /* The docid from pLeft and pRight */
|
|
DocList *pOut /* Write the merged document record here */
|
|
){
|
|
int iLeftCol, iLeftPos = readPosition(pLeft, &iLeftCol);
|
|
int iRightCol, iRightPos = readPosition(pRight, &iRightCol);
|
|
int match = 0;
|
|
|
|
/* Loop until we've reached the end of both position lists. */
|
|
while( iLeftPos!=-1 && iRightPos!=-1 ){
|
|
if( iLeftCol==iRightCol && iLeftPos+1==iRightPos ){
|
|
if( !match ){
|
|
docListAddDocid(pOut, iDocid);
|
|
match = 1;
|
|
}
|
|
if( pOut->iType>=DL_POSITIONS ){
|
|
docListAddPos(pOut, iRightCol, iRightPos);
|
|
}
|
|
iLeftPos = readPosition(pLeft, &iLeftCol);
|
|
iRightPos = readPosition(pRight, &iRightCol);
|
|
}else if( iRightCol<iLeftCol ||
|
|
(iRightCol==iLeftCol && iRightPos<iLeftPos+1) ){
|
|
iRightPos = readPosition(pRight, &iRightCol);
|
|
}else{
|
|
iLeftPos = readPosition(pLeft, &iLeftCol);
|
|
}
|
|
}
|
|
if( iLeftPos>=0 ) skipPositionList(pLeft);
|
|
if( iRightPos>=0 ) skipPositionList(pRight);
|
|
}
|
|
|
|
/* We have two doclists: pLeft and pRight.
|
|
** Write the phrase intersection of these two doclists into pOut.
|
|
**
|
|
** A phrase intersection means that two documents only match
|
|
** if pLeft.iPos+1==pRight.iPos.
|
|
**
|
|
** The output pOut may or may not contain positions. If pOut
|
|
** does contain positions, they are the positions of pRight.
|
|
*/
|
|
static void docListPhraseMerge(
|
|
DocList *pLeft, /* Doclist resulting from the words on the left */
|
|
DocList *pRight, /* Doclist for the next word to the right */
|
|
DocList *pOut /* Write the combined doclist here */
|
|
){
|
|
DocListReader left, right;
|
|
sqlite_int64 docidLeft, docidRight;
|
|
|
|
readerInit(&left, pLeft);
|
|
readerInit(&right, pRight);
|
|
docidLeft = nextDocid(&left);
|
|
docidRight = nextDocid(&right);
|
|
|
|
while( docidLeft>0 && docidRight>0 ){
|
|
if( docidLeft<docidRight ){
|
|
docidLeft = nextDocid(&left);
|
|
}else if( docidRight<docidLeft ){
|
|
docidRight = nextDocid(&right);
|
|
}else{
|
|
mergePosList(&left, &right, docidLeft, pOut);
|
|
docidLeft = nextDocid(&left);
|
|
docidRight = nextDocid(&right);
|
|
}
|
|
}
|
|
}
|
|
|
|
/* We have two doclists: pLeft and pRight.
|
|
** Write the intersection of these two doclists into pOut.
|
|
** Only docids are matched. Position information is ignored.
|
|
**
|
|
** The output pOut never holds positions.
|
|
*/
|
|
static void docListAndMerge(
|
|
DocList *pLeft, /* Doclist resulting from the words on the left */
|
|
DocList *pRight, /* Doclist for the next word to the right */
|
|
DocList *pOut /* Write the combined doclist here */
|
|
){
|
|
DocListReader left, right;
|
|
sqlite_int64 docidLeft, docidRight;
|
|
|
|
assert( pOut->iType<DL_POSITIONS );
|
|
|
|
readerInit(&left, pLeft);
|
|
readerInit(&right, pRight);
|
|
docidLeft = nextDocid(&left);
|
|
docidRight = nextDocid(&right);
|
|
|
|
while( docidLeft>0 && docidRight>0 ){
|
|
if( docidLeft<docidRight ){
|
|
docidLeft = nextDocid(&left);
|
|
}else if( docidRight<docidLeft ){
|
|
docidRight = nextDocid(&right);
|
|
}else{
|
|
docListAddDocid(pOut, docidLeft);
|
|
docidLeft = nextDocid(&left);
|
|
docidRight = nextDocid(&right);
|
|
}
|
|
}
|
|
}
|
|
|
|
/* We have two doclists: pLeft and pRight.
|
|
** Write the union of these two doclists into pOut.
|
|
** Only docids are matched. Position information is ignored.
|
|
**
|
|
** The output pOut never holds positions.
|
|
*/
|
|
static void docListOrMerge(
|
|
DocList *pLeft, /* Doclist resulting from the words on the left */
|
|
DocList *pRight, /* Doclist for the next word to the right */
|
|
DocList *pOut /* Write the combined doclist here */
|
|
){
|
|
DocListReader left, right;
|
|
sqlite_int64 docidLeft, docidRight, priorLeft;
|
|
|
|
readerInit(&left, pLeft);
|
|
readerInit(&right, pRight);
|
|
docidLeft = nextDocid(&left);
|
|
docidRight = nextDocid(&right);
|
|
|
|
while( docidLeft>0 && docidRight>0 ){
|
|
if( docidLeft<=docidRight ){
|
|
docListAddDocid(pOut, docidLeft);
|
|
}else{
|
|
docListAddDocid(pOut, docidRight);
|
|
}
|
|
priorLeft = docidLeft;
|
|
if( docidLeft<=docidRight ){
|
|
docidLeft = nextDocid(&left);
|
|
}
|
|
if( docidRight>0 && docidRight<=priorLeft ){
|
|
docidRight = nextDocid(&right);
|
|
}
|
|
}
|
|
while( docidLeft>0 ){
|
|
docListAddDocid(pOut, docidLeft);
|
|
docidLeft = nextDocid(&left);
|
|
}
|
|
while( docidRight>0 ){
|
|
docListAddDocid(pOut, docidRight);
|
|
docidRight = nextDocid(&right);
|
|
}
|
|
}
|
|
|
|
/* We have two doclists: pLeft and pRight.
|
|
** Write into pOut all documents that occur in pLeft but not
|
|
** in pRight.
|
|
**
|
|
** Only docids are matched. Position information is ignored.
|
|
**
|
|
** The output pOut never holds positions.
|
|
*/
|
|
static void docListExceptMerge(
|
|
DocList *pLeft, /* Doclist resulting from the words on the left */
|
|
DocList *pRight, /* Doclist for the next word to the right */
|
|
DocList *pOut /* Write the combined doclist here */
|
|
){
|
|
DocListReader left, right;
|
|
sqlite_int64 docidLeft, docidRight, priorLeft;
|
|
|
|
readerInit(&left, pLeft);
|
|
readerInit(&right, pRight);
|
|
docidLeft = nextDocid(&left);
|
|
docidRight = nextDocid(&right);
|
|
|
|
while( docidLeft>0 && docidRight>0 ){
|
|
priorLeft = docidLeft;
|
|
if( docidLeft<docidRight ){
|
|
docListAddDocid(pOut, docidLeft);
|
|
}
|
|
if( docidLeft<=docidRight ){
|
|
docidLeft = nextDocid(&left);
|
|
}
|
|
if( docidRight>0 && docidRight<=priorLeft ){
|
|
docidRight = nextDocid(&right);
|
|
}
|
|
}
|
|
while( docidLeft>0 ){
|
|
docListAddDocid(pOut, docidLeft);
|
|
docidLeft = nextDocid(&left);
|
|
}
|
|
}
|
|
|
|
static char *string_dup_n(const char *s, int n){
|
|
char *str = malloc(n + 1);
|
|
memcpy(str, s, n);
|
|
str[n] = '\0';
|
|
return str;
|
|
}
|
|
|
|
/* Duplicate a string; the caller must free() the returned string.
|
|
* (We don't use strdup() since it is not part of the standard C library and
|
|
* may not be available everywhere.) */
|
|
static char *string_dup(const char *s){
|
|
return string_dup_n(s, strlen(s));
|
|
}
|
|
|
|
/* Format a string, replacing each occurrence of the % character with
|
|
* zDb.zName. This may be more convenient than sqlite_mprintf()
|
|
* when one string is used repeatedly in a format string.
|
|
* The caller must free() the returned string. */
|
|
static char *string_format(const char *zFormat,
|
|
const char *zDb, const char *zName){
|
|
const char *p;
|
|
size_t len = 0;
|
|
size_t nDb = strlen(zDb);
|
|
size_t nName = strlen(zName);
|
|
size_t nFullTableName = nDb+1+nName;
|
|
char *result;
|
|
char *r;
|
|
|
|
/* first compute length needed */
|
|
for(p = zFormat ; *p ; ++p){
|
|
len += (*p=='%' ? nFullTableName : 1);
|
|
}
|
|
len += 1; /* for null terminator */
|
|
|
|
r = result = malloc(len);
|
|
for(p = zFormat; *p; ++p){
|
|
if( *p=='%' ){
|
|
memcpy(r, zDb, nDb);
|
|
r += nDb;
|
|
*r++ = '.';
|
|
memcpy(r, zName, nName);
|
|
r += nName;
|
|
} else {
|
|
*r++ = *p;
|
|
}
|
|
}
|
|
*r++ = '\0';
|
|
assert( r == result + len );
|
|
return result;
|
|
}
|
|
|
|
static int sql_exec(sqlite3 *db, const char *zDb, const char *zName,
|
|
const char *zFormat){
|
|
char *zCommand = string_format(zFormat, zDb, zName);
|
|
int rc;
|
|
TRACE(("FTS1 sql: %s\n", zCommand));
|
|
rc = sqlite3_exec(db, zCommand, NULL, 0, NULL);
|
|
free(zCommand);
|
|
return rc;
|
|
}
|
|
|
|
static int sql_prepare(sqlite3 *db, const char *zDb, const char *zName,
|
|
sqlite3_stmt **ppStmt, const char *zFormat){
|
|
char *zCommand = string_format(zFormat, zDb, zName);
|
|
int rc;
|
|
TRACE(("FTS1 prepare: %s\n", zCommand));
|
|
rc = sqlite3_prepare(db, zCommand, -1, ppStmt, NULL);
|
|
free(zCommand);
|
|
return rc;
|
|
}
|
|
|
|
/* end utility functions */
|
|
|
|
/* Forward reference */
|
|
typedef struct fulltext_vtab fulltext_vtab;
|
|
|
|
/* A single term in a query is represented by an instances of
|
|
** the following structure.
|
|
*/
|
|
typedef struct QueryTerm {
|
|
short int nPhrase; /* How many following terms are part of the same phrase */
|
|
short int iPhrase; /* This is the i-th term of a phrase. */
|
|
short int iColumn; /* Column of the index that must match this term */
|
|
signed char isOr; /* this term is preceded by "OR" */
|
|
signed char isNot; /* this term is preceded by "-" */
|
|
char *pTerm; /* text of the term. '\000' terminated. malloced */
|
|
int nTerm; /* Number of bytes in pTerm[] */
|
|
} QueryTerm;
|
|
|
|
|
|
/* A query string is parsed into a Query structure.
|
|
*
|
|
* We could, in theory, allow query strings to be complicated
|
|
* nested expressions with precedence determined by parentheses.
|
|
* But none of the major search engines do this. (Perhaps the
|
|
* feeling is that an parenthesized expression is two complex of
|
|
* an idea for the average user to grasp.) Taking our lead from
|
|
* the major search engines, we will allow queries to be a list
|
|
* of terms (with an implied AND operator) or phrases in double-quotes,
|
|
* with a single optional "-" before each non-phrase term to designate
|
|
* negation and an optional OR connector.
|
|
*
|
|
* OR binds more tightly than the implied AND, which is what the
|
|
* major search engines seem to do. So, for example:
|
|
*
|
|
* [one two OR three] ==> one AND (two OR three)
|
|
* [one OR two three] ==> (one OR two) AND three
|
|
*
|
|
* A "-" before a term matches all entries that lack that term.
|
|
* The "-" must occur immediately before the term with in intervening
|
|
* space. This is how the search engines do it.
|
|
*
|
|
* A NOT term cannot be the right-hand operand of an OR. If this
|
|
* occurs in the query string, the NOT is ignored:
|
|
*
|
|
* [one OR -two] ==> one OR two
|
|
*
|
|
*/
|
|
typedef struct Query {
|
|
fulltext_vtab *pFts; /* The full text index */
|
|
int nTerms; /* Number of terms in the query */
|
|
QueryTerm *pTerms; /* Array of terms. Space obtained from malloc() */
|
|
int nextIsOr; /* Set the isOr flag on the next inserted term */
|
|
int nextColumn; /* Next word parsed must be in this column */
|
|
int dfltColumn; /* The default column */
|
|
} Query;
|
|
|
|
|
|
/*
|
|
** An instance of the following structure keeps track of generated
|
|
** matching-word offset information and snippets.
|
|
*/
|
|
typedef struct Snippet {
|
|
int nMatch; /* Total number of matches */
|
|
int nAlloc; /* Space allocated for aMatch[] */
|
|
struct snippetMatch { /* One entry for each matching term */
|
|
char snStatus; /* Status flag for use while constructing snippets */
|
|
short int iCol; /* The column that contains the match */
|
|
short int iTerm; /* The index in Query.pTerms[] of the matching term */
|
|
short int nByte; /* Number of bytes in the term */
|
|
int iStart; /* The offset to the first character of the term */
|
|
} *aMatch; /* Points to space obtained from malloc */
|
|
char *zOffset; /* Text rendering of aMatch[] */
|
|
int nOffset; /* strlen(zOffset) */
|
|
char *zSnippet; /* Snippet text */
|
|
int nSnippet; /* strlen(zSnippet) */
|
|
} Snippet;
|
|
|
|
|
|
typedef enum QueryType {
|
|
QUERY_GENERIC, /* table scan */
|
|
QUERY_ROWID, /* lookup by rowid */
|
|
QUERY_FULLTEXT /* QUERY_FULLTEXT + [i] is a full-text search for column i*/
|
|
} QueryType;
|
|
|
|
/* TODO(shess) CHUNK_MAX controls how much data we allow in segment 0
|
|
** before we start aggregating into larger segments. Lower CHUNK_MAX
|
|
** means that for a given input we have more individual segments per
|
|
** term, which means more rows in the table and a bigger index (due to
|
|
** both more rows and bigger rowids). But it also reduces the average
|
|
** cost of adding new elements to the segment 0 doclist, and it seems
|
|
** to reduce the number of pages read and written during inserts. 256
|
|
** was chosen by measuring insertion times for a certain input (first
|
|
** 10k documents of Enron corpus), though including query performance
|
|
** in the decision may argue for a larger value.
|
|
*/
|
|
#define CHUNK_MAX 256
|
|
|
|
typedef enum fulltext_statement {
|
|
CONTENT_INSERT_STMT,
|
|
CONTENT_SELECT_STMT,
|
|
CONTENT_UPDATE_STMT,
|
|
CONTENT_DELETE_STMT,
|
|
|
|
TERM_SELECT_STMT,
|
|
TERM_SELECT_ALL_STMT,
|
|
TERM_INSERT_STMT,
|
|
TERM_UPDATE_STMT,
|
|
TERM_DELETE_STMT,
|
|
|
|
MAX_STMT /* Always at end! */
|
|
} fulltext_statement;
|
|
|
|
/* These must exactly match the enum above. */
|
|
/* TODO(adam): Is there some risk that a statement (in particular,
|
|
** pTermSelectStmt) will be used in two cursors at once, e.g. if a
|
|
** query joins a virtual table to itself? If so perhaps we should
|
|
** move some of these to the cursor object.
|
|
*/
|
|
static const char *const fulltext_zStatement[MAX_STMT] = {
|
|
/* CONTENT_INSERT */ NULL, /* generated in contentInsertStatement() */
|
|
/* CONTENT_SELECT */ "select * from %_content where rowid = ?",
|
|
/* CONTENT_UPDATE */ NULL, /* generated in contentUpdateStatement() */
|
|
/* CONTENT_DELETE */ "delete from %_content where rowid = ?",
|
|
|
|
/* TERM_SELECT */
|
|
"select rowid, doclist from %_term where term = ? and segment = ?",
|
|
/* TERM_SELECT_ALL */
|
|
"select doclist from %_term where term = ? order by segment",
|
|
/* TERM_INSERT */
|
|
"insert into %_term (rowid, term, segment, doclist) values (?, ?, ?, ?)",
|
|
/* TERM_UPDATE */ "update %_term set doclist = ? where rowid = ?",
|
|
/* TERM_DELETE */ "delete from %_term where rowid = ?",
|
|
};
|
|
|
|
/*
|
|
** A connection to a fulltext index is an instance of the following
|
|
** structure. The xCreate and xConnect methods create an instance
|
|
** of this structure and xDestroy and xDisconnect free that instance.
|
|
** All other methods receive a pointer to the structure as one of their
|
|
** arguments.
|
|
*/
|
|
struct fulltext_vtab {
|
|
sqlite3_vtab base; /* Base class used by SQLite core */
|
|
sqlite3 *db; /* The database connection */
|
|
const char *zDb; /* logical database name */
|
|
const char *zName; /* virtual table name */
|
|
int nColumn; /* number of columns in virtual table */
|
|
char **azColumn; /* column names. malloced */
|
|
char **azContentColumn; /* column names in content table; malloced */
|
|
sqlite3_tokenizer *pTokenizer; /* tokenizer for inserts and queries */
|
|
|
|
/* Precompiled statements which we keep as long as the table is
|
|
** open.
|
|
*/
|
|
sqlite3_stmt *pFulltextStatements[MAX_STMT];
|
|
};
|
|
|
|
/*
|
|
** When the core wants to do a query, it create a cursor using a
|
|
** call to xOpen. This structure is an instance of a cursor. It
|
|
** is destroyed by xClose.
|
|
*/
|
|
typedef struct fulltext_cursor {
|
|
sqlite3_vtab_cursor base; /* Base class used by SQLite core */
|
|
QueryType iCursorType; /* Copy of sqlite3_index_info.idxNum */
|
|
sqlite3_stmt *pStmt; /* Prepared statement in use by the cursor */
|
|
int eof; /* True if at End Of Results */
|
|
Query q; /* Parsed query string */
|
|
Snippet snippet; /* Cached snippet for the current row */
|
|
int iColumn; /* Column being searched */
|
|
DocListReader result; /* used when iCursorType == QUERY_FULLTEXT */
|
|
} fulltext_cursor;
|
|
|
|
static struct fulltext_vtab *cursor_vtab(fulltext_cursor *c){
|
|
return (fulltext_vtab *) c->base.pVtab;
|
|
}
|
|
|
|
static const sqlite3_module fulltextModule; /* forward declaration */
|
|
|
|
/* Append a list of strings separated by commas to a StringBuffer. */
|
|
static void appendList(StringBuffer *sb, int nString, char **azString){
|
|
int i;
|
|
for(i=0; i<nString; ++i){
|
|
if( i>0 ) append(sb, ", ");
|
|
append(sb, azString[i]);
|
|
}
|
|
}
|
|
|
|
/* Return a dynamically generated statement of the form
|
|
* insert into %_content (rowid, ...) values (?, ...)
|
|
*/
|
|
static const char *contentInsertStatement(fulltext_vtab *v){
|
|
StringBuffer sb;
|
|
int i;
|
|
|
|
initStringBuffer(&sb);
|
|
append(&sb, "insert into %_content (rowid, ");
|
|
appendList(&sb, v->nColumn, v->azContentColumn);
|
|
append(&sb, ") values (?");
|
|
for(i=0; i<v->nColumn; ++i)
|
|
append(&sb, ", ?");
|
|
append(&sb, ")");
|
|
return sb.s;
|
|
}
|
|
|
|
/* Return a dynamically generated statement of the form
|
|
* update %_content set [col_0] = ?, [col_1] = ?, ...
|
|
* where rowid = ?
|
|
*/
|
|
static const char *contentUpdateStatement(fulltext_vtab *v){
|
|
StringBuffer sb;
|
|
int i;
|
|
|
|
initStringBuffer(&sb);
|
|
append(&sb, "update %_content set ");
|
|
for(i=0; i<v->nColumn; ++i) {
|
|
if( i>0 ){
|
|
append(&sb, ", ");
|
|
}
|
|
append(&sb, v->azContentColumn[i]);
|
|
append(&sb, " = ?");
|
|
}
|
|
append(&sb, " where rowid = ?");
|
|
return sb.s;
|
|
}
|
|
|
|
/* Puts a freshly-prepared statement determined by iStmt in *ppStmt.
|
|
** If the indicated statement has never been prepared, it is prepared
|
|
** and cached, otherwise the cached version is reset.
|
|
*/
|
|
static int sql_get_statement(fulltext_vtab *v, fulltext_statement iStmt,
|
|
sqlite3_stmt **ppStmt){
|
|
assert( iStmt<MAX_STMT );
|
|
if( v->pFulltextStatements[iStmt]==NULL ){
|
|
const char *zStmt;
|
|
int rc;
|
|
switch( iStmt ){
|
|
case CONTENT_INSERT_STMT:
|
|
zStmt = contentInsertStatement(v); break;
|
|
case CONTENT_UPDATE_STMT:
|
|
zStmt = contentUpdateStatement(v); break;
|
|
default:
|
|
zStmt = fulltext_zStatement[iStmt];
|
|
}
|
|
rc = sql_prepare(v->db, v->zDb, v->zName, &v->pFulltextStatements[iStmt],
|
|
zStmt);
|
|
if( zStmt != fulltext_zStatement[iStmt]) free((void *) zStmt);
|
|
if( rc!=SQLITE_OK ) return rc;
|
|
} else {
|
|
int rc = sqlite3_reset(v->pFulltextStatements[iStmt]);
|
|
if( rc!=SQLITE_OK ) return rc;
|
|
}
|
|
|
|
*ppStmt = v->pFulltextStatements[iStmt];
|
|
return SQLITE_OK;
|
|
}
|
|
|
|
/* Step the indicated statement, handling errors SQLITE_BUSY (by
|
|
** retrying) and SQLITE_SCHEMA (by re-preparing and transferring
|
|
** bindings to the new statement).
|
|
** TODO(adam): We should extend this function so that it can work with
|
|
** statements declared locally, not only globally cached statements.
|
|
*/
|
|
static int sql_step_statement(fulltext_vtab *v, fulltext_statement iStmt,
|
|
sqlite3_stmt **ppStmt){
|
|
int rc;
|
|
sqlite3_stmt *s = *ppStmt;
|
|
assert( iStmt<MAX_STMT );
|
|
assert( s==v->pFulltextStatements[iStmt] );
|
|
|
|
while( (rc=sqlite3_step(s))!=SQLITE_DONE && rc!=SQLITE_ROW ){
|
|
if( rc==SQLITE_BUSY ) continue;
|
|
if( rc!=SQLITE_ERROR ) return rc;
|
|
|
|
/* If an SQLITE_SCHEMA error has occurred, then finalizing this
|
|
* statement is going to delete the fulltext_vtab structure. If
|
|
* the statement just executed is in the pFulltextStatements[]
|
|
* array, it will be finalized twice. So remove it before
|
|
* calling sqlite3_finalize().
|
|
*/
|
|
v->pFulltextStatements[iStmt] = NULL;
|
|
rc = sqlite3_finalize(s);
|
|
break;
|
|
}
|
|
return rc;
|
|
|
|
err:
|
|
sqlite3_finalize(s);
|
|
return rc;
|
|
}
|
|
|
|
/* Like sql_step_statement(), but convert SQLITE_DONE to SQLITE_OK.
|
|
** Useful for statements like UPDATE, where we expect no results.
|
|
*/
|
|
static int sql_single_step_statement(fulltext_vtab *v,
|
|
fulltext_statement iStmt,
|
|
sqlite3_stmt **ppStmt){
|
|
int rc = sql_step_statement(v, iStmt, ppStmt);
|
|
return (rc==SQLITE_DONE) ? SQLITE_OK : rc;
|
|
}
|
|
|
|
/* insert into %_content (rowid, ...) values ([rowid], [pValues]) */
|
|
static int content_insert(fulltext_vtab *v, sqlite3_value *rowid,
|
|
sqlite3_value **pValues){
|
|
sqlite3_stmt *s;
|
|
int i;
|
|
int rc = sql_get_statement(v, CONTENT_INSERT_STMT, &s);
|
|
if( rc!=SQLITE_OK ) return rc;
|
|
|
|
rc = sqlite3_bind_value(s, 1, rowid);
|
|
if( rc!=SQLITE_OK ) return rc;
|
|
|
|
for(i=0; i<v->nColumn; ++i){
|
|
rc = sqlite3_bind_value(s, 2+i, pValues[i]);
|
|
if( rc!=SQLITE_OK ) return rc;
|
|
}
|
|
|
|
return sql_single_step_statement(v, CONTENT_INSERT_STMT, &s);
|
|
}
|
|
|
|
/* update %_content set col0 = pValues[0], col1 = pValues[1], ...
|
|
* where rowid = [iRowid] */
|
|
static int content_update(fulltext_vtab *v, sqlite3_value **pValues,
|
|
sqlite_int64 iRowid){
|
|
sqlite3_stmt *s;
|
|
int i;
|
|
int rc = sql_get_statement(v, CONTENT_UPDATE_STMT, &s);
|
|
if( rc!=SQLITE_OK ) return rc;
|
|
|
|
for(i=0; i<v->nColumn; ++i){
|
|
rc = sqlite3_bind_value(s, 1+i, pValues[i]);
|
|
if( rc!=SQLITE_OK ) return rc;
|
|
}
|
|
|
|
rc = sqlite3_bind_int64(s, 1+v->nColumn, iRowid);
|
|
if( rc!=SQLITE_OK ) return rc;
|
|
|
|
return sql_single_step_statement(v, CONTENT_UPDATE_STMT, &s);
|
|
}
|
|
|
|
static void freeStringArray(int nString, const char **pString){
|
|
int i;
|
|
|
|
for (i=0 ; i < nString ; ++i) {
|
|
if( pString[i]!=NULL ) free((void *) pString[i]);
|
|
}
|
|
free((void *) pString);
|
|
}
|
|
|
|
/* select * from %_content where rowid = [iRow]
|
|
* The caller must delete the returned array and all strings in it.
|
|
* null fields will be NULL in the returned array.
|
|
*
|
|
* TODO: Perhaps we should return pointer/length strings here for consistency
|
|
* with other code which uses pointer/length. */
|
|
static int content_select(fulltext_vtab *v, sqlite_int64 iRow,
|
|
const char ***pValues){
|
|
sqlite3_stmt *s;
|
|
const char **values;
|
|
int i;
|
|
int rc;
|
|
|
|
*pValues = NULL;
|
|
|
|
rc = sql_get_statement(v, CONTENT_SELECT_STMT, &s);
|
|
if( rc!=SQLITE_OK ) return rc;
|
|
|
|
rc = sqlite3_bind_int64(s, 1, iRow);
|
|
if( rc!=SQLITE_OK ) return rc;
|
|
|
|
rc = sql_step_statement(v, CONTENT_SELECT_STMT, &s);
|
|
if( rc!=SQLITE_ROW ) return rc;
|
|
|
|
values = (const char **) malloc(v->nColumn * sizeof(const char *));
|
|
for(i=0; i<v->nColumn; ++i){
|
|
if( sqlite3_column_type(s, i)==SQLITE_NULL ){
|
|
values[i] = NULL;
|
|
}else{
|
|
values[i] = string_dup((char*)sqlite3_column_text(s, i));
|
|
}
|
|
}
|
|
|
|
/* We expect only one row. We must execute another sqlite3_step()
|
|
* to complete the iteration; otherwise the table will remain locked. */
|
|
rc = sqlite3_step(s);
|
|
if( rc==SQLITE_DONE ){
|
|
*pValues = values;
|
|
return SQLITE_OK;
|
|
}
|
|
|
|
freeStringArray(v->nColumn, values);
|
|
return rc;
|
|
}
|
|
|
|
/* delete from %_content where rowid = [iRow ] */
|
|
static int content_delete(fulltext_vtab *v, sqlite_int64 iRow){
|
|
sqlite3_stmt *s;
|
|
int rc = sql_get_statement(v, CONTENT_DELETE_STMT, &s);
|
|
if( rc!=SQLITE_OK ) return rc;
|
|
|
|
rc = sqlite3_bind_int64(s, 1, iRow);
|
|
if( rc!=SQLITE_OK ) return rc;
|
|
|
|
return sql_single_step_statement(v, CONTENT_DELETE_STMT, &s);
|
|
}
|
|
|
|
/* select rowid, doclist from %_term
|
|
* where term = [pTerm] and segment = [iSegment]
|
|
* If found, returns SQLITE_ROW; the caller must free the
|
|
* returned doclist. If no rows found, returns SQLITE_DONE. */
|
|
static int term_select(fulltext_vtab *v, const char *pTerm, int nTerm,
|
|
int iSegment,
|
|
sqlite_int64 *rowid, DocList *out){
|
|
sqlite3_stmt *s;
|
|
int rc = sql_get_statement(v, TERM_SELECT_STMT, &s);
|
|
if( rc!=SQLITE_OK ) return rc;
|
|
|
|
rc = sqlite3_bind_text(s, 1, pTerm, nTerm, SQLITE_STATIC);
|
|
if( rc!=SQLITE_OK ) return rc;
|
|
|
|
rc = sqlite3_bind_int(s, 2, iSegment);
|
|
if( rc!=SQLITE_OK ) return rc;
|
|
|
|
rc = sql_step_statement(v, TERM_SELECT_STMT, &s);
|
|
if( rc!=SQLITE_ROW ) return rc;
|
|
|
|
*rowid = sqlite3_column_int64(s, 0);
|
|
docListInit(out, DL_DEFAULT,
|
|
sqlite3_column_blob(s, 1), sqlite3_column_bytes(s, 1));
|
|
|
|
/* We expect only one row. We must execute another sqlite3_step()
|
|
* to complete the iteration; otherwise the table will remain locked. */
|
|
rc = sqlite3_step(s);
|
|
return rc==SQLITE_DONE ? SQLITE_ROW : rc;
|
|
}
|
|
|
|
/* Load the segment doclists for term pTerm and merge them in
|
|
** appropriate order into out. Returns SQLITE_OK if successful. If
|
|
** there are no segments for pTerm, successfully returns an empty
|
|
** doclist in out.
|
|
**
|
|
** Each document consists of 1 or more "columns". The number of
|
|
** columns is v->nColumn. If iColumn==v->nColumn, then return
|
|
** position information about all columns. If iColumn<v->nColumn,
|
|
** then only return position information about the iColumn-th column
|
|
** (where the first column is 0).
|
|
*/
|
|
static int term_select_all(
|
|
fulltext_vtab *v, /* The fulltext index we are querying against */
|
|
int iColumn, /* If <nColumn, only look at the iColumn-th column */
|
|
const char *pTerm, /* The term whose posting lists we want */
|
|
int nTerm, /* Number of bytes in pTerm */
|
|
DocList *out /* Write the resulting doclist here */
|
|
){
|
|
DocList doclist;
|
|
sqlite3_stmt *s;
|
|
int rc = sql_get_statement(v, TERM_SELECT_ALL_STMT, &s);
|
|
if( rc!=SQLITE_OK ) return rc;
|
|
|
|
rc = sqlite3_bind_text(s, 1, pTerm, nTerm, SQLITE_STATIC);
|
|
if( rc!=SQLITE_OK ) return rc;
|
|
|
|
docListInit(&doclist, DL_DEFAULT, 0, 0);
|
|
|
|
/* TODO(shess) Handle schema and busy errors. */
|
|
while( (rc=sql_step_statement(v, TERM_SELECT_ALL_STMT, &s))==SQLITE_ROW ){
|
|
DocList old;
|
|
|
|
/* TODO(shess) If we processed doclists from oldest to newest, we
|
|
** could skip the malloc() involved with the following call. For
|
|
** now, I'd rather keep this logic similar to index_insert_term().
|
|
** We could additionally drop elements when we see deletes, but
|
|
** that would require a distinct version of docListAccumulate().
|
|
*/
|
|
docListInit(&old, DL_DEFAULT,
|
|
sqlite3_column_blob(s, 0), sqlite3_column_bytes(s, 0));
|
|
|
|
if( iColumn<v->nColumn ){ /* querying a single column */
|
|
docListRestrictColumn(&old, iColumn);
|
|
}
|
|
|
|
/* doclist contains the newer data, so write it over old. Then
|
|
** steal accumulated result for doclist.
|
|
*/
|
|
docListAccumulate(&old, &doclist);
|
|
docListDestroy(&doclist);
|
|
doclist = old;
|
|
}
|
|
if( rc!=SQLITE_DONE ){
|
|
docListDestroy(&doclist);
|
|
return rc;
|
|
}
|
|
|
|
docListDiscardEmpty(&doclist);
|
|
*out = doclist;
|
|
return SQLITE_OK;
|
|
}
|
|
|
|
/* insert into %_term (rowid, term, segment, doclist)
|
|
values ([piRowid], [pTerm], [iSegment], [doclist])
|
|
** Lets sqlite select rowid if piRowid is NULL, else uses *piRowid.
|
|
**
|
|
** NOTE(shess) piRowid is IN, with values of "space of int64" plus
|
|
** null, it is not used to pass data back to the caller.
|
|
*/
|
|
static int term_insert(fulltext_vtab *v, sqlite_int64 *piRowid,
|
|
const char *pTerm, int nTerm,
|
|
int iSegment, DocList *doclist){
|
|
sqlite3_stmt *s;
|
|
int rc = sql_get_statement(v, TERM_INSERT_STMT, &s);
|
|
if( rc!=SQLITE_OK ) return rc;
|
|
|
|
if( piRowid==NULL ){
|
|
rc = sqlite3_bind_null(s, 1);
|
|
}else{
|
|
rc = sqlite3_bind_int64(s, 1, *piRowid);
|
|
}
|
|
if( rc!=SQLITE_OK ) return rc;
|
|
|
|
rc = sqlite3_bind_text(s, 2, pTerm, nTerm, SQLITE_STATIC);
|
|
if( rc!=SQLITE_OK ) return rc;
|
|
|
|
rc = sqlite3_bind_int(s, 3, iSegment);
|
|
if( rc!=SQLITE_OK ) return rc;
|
|
|
|
rc = sqlite3_bind_blob(s, 4, doclist->pData, doclist->nData, SQLITE_STATIC);
|
|
if( rc!=SQLITE_OK ) return rc;
|
|
|
|
return sql_single_step_statement(v, TERM_INSERT_STMT, &s);
|
|
}
|
|
|
|
/* update %_term set doclist = [doclist] where rowid = [rowid] */
|
|
static int term_update(fulltext_vtab *v, sqlite_int64 rowid,
|
|
DocList *doclist){
|
|
sqlite3_stmt *s;
|
|
int rc = sql_get_statement(v, TERM_UPDATE_STMT, &s);
|
|
if( rc!=SQLITE_OK ) return rc;
|
|
|
|
rc = sqlite3_bind_blob(s, 1, doclist->pData, doclist->nData, SQLITE_STATIC);
|
|
if( rc!=SQLITE_OK ) return rc;
|
|
|
|
rc = sqlite3_bind_int64(s, 2, rowid);
|
|
if( rc!=SQLITE_OK ) return rc;
|
|
|
|
return sql_single_step_statement(v, TERM_UPDATE_STMT, &s);
|
|
}
|
|
|
|
static int term_delete(fulltext_vtab *v, sqlite_int64 rowid){
|
|
sqlite3_stmt *s;
|
|
int rc = sql_get_statement(v, TERM_DELETE_STMT, &s);
|
|
if( rc!=SQLITE_OK ) return rc;
|
|
|
|
rc = sqlite3_bind_int64(s, 1, rowid);
|
|
if( rc!=SQLITE_OK ) return rc;
|
|
|
|
return sql_single_step_statement(v, TERM_DELETE_STMT, &s);
|
|
}
|
|
|
|
/*
|
|
** Free the memory used to contain a fulltext_vtab structure.
|
|
*/
|
|
static void fulltext_vtab_destroy(fulltext_vtab *v){
|
|
int iStmt, i;
|
|
|
|
TRACE(("FTS1 Destroy %p\n", v));
|
|
for( iStmt=0; iStmt<MAX_STMT; iStmt++ ){
|
|
if( v->pFulltextStatements[iStmt]!=NULL ){
|
|
sqlite3_finalize(v->pFulltextStatements[iStmt]);
|
|
v->pFulltextStatements[iStmt] = NULL;
|
|
}
|
|
}
|
|
|
|
if( v->pTokenizer!=NULL ){
|
|
v->pTokenizer->pModule->xDestroy(v->pTokenizer);
|
|
v->pTokenizer = NULL;
|
|
}
|
|
|
|
free(v->azColumn);
|
|
for(i = 0; i < v->nColumn; ++i) {
|
|
sqlite3_free(v->azContentColumn[i]);
|
|
}
|
|
free(v->azContentColumn);
|
|
free(v);
|
|
}
|
|
|
|
/*
|
|
** Token types for parsing the arguments to xConnect or xCreate.
|
|
*/
|
|
#define TOKEN_EOF 0 /* End of file */
|
|
#define TOKEN_SPACE 1 /* Any kind of whitespace */
|
|
#define TOKEN_ID 2 /* An identifier */
|
|
#define TOKEN_STRING 3 /* A string literal */
|
|
#define TOKEN_PUNCT 4 /* A single punctuation character */
|
|
|
|
/*
|
|
** If X is a character that can be used in an identifier then
|
|
** IdChar(X) will be true. Otherwise it is false.
|
|
**
|
|
** For ASCII, any character with the high-order bit set is
|
|
** allowed in an identifier. For 7-bit characters,
|
|
** sqlite3IsIdChar[X] must be 1.
|
|
**
|
|
** Ticket #1066. the SQL standard does not allow '$' in the
|
|
** middle of identfiers. But many SQL implementations do.
|
|
** SQLite will allow '$' in identifiers for compatibility.
|
|
** But the feature is undocumented.
|
|
*/
|
|
static const char isIdChar[] = {
|
|
/* x0 x1 x2 x3 x4 x5 x6 x7 x8 x9 xA xB xC xD xE xF */
|
|
0, 0, 0, 0, 1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, /* 2x */
|
|
1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 0, 0, 0, 0, 0, 0, /* 3x */
|
|
0, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, /* 4x */
|
|
1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 0, 0, 0, 0, 1, /* 5x */
|
|
0, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, /* 6x */
|
|
1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 0, 0, 0, 0, 0, /* 7x */
|
|
};
|
|
#define IdChar(C) (((c=C)&0x80)!=0 || (c>0x1f && isIdChar[c-0x20]))
|
|
|
|
|
|
/*
|
|
** Return the length of the token that begins at z[0].
|
|
** Store the token type in *tokenType before returning.
|
|
*/
|
|
static int getToken(const char *z, int *tokenType){
|
|
int i, c;
|
|
switch( *z ){
|
|
case 0: {
|
|
*tokenType = TOKEN_EOF;
|
|
return 0;
|
|
}
|
|
case ' ': case '\t': case '\n': case '\f': case '\r': {
|
|
for(i=1; safe_isspace(z[i]); i++){}
|
|
*tokenType = TOKEN_SPACE;
|
|
return i;
|
|
}
|
|
case '`':
|
|
case '\'':
|
|
case '"': {
|
|
int delim = z[0];
|
|
for(i=1; (c=z[i])!=0; i++){
|
|
if( c==delim ){
|
|
if( z[i+1]==delim ){
|
|
i++;
|
|
}else{
|
|
break;
|
|
}
|
|
}
|
|
}
|
|
*tokenType = TOKEN_STRING;
|
|
return i + (c!=0);
|
|
}
|
|
case '[': {
|
|
for(i=1, c=z[0]; c!=']' && (c=z[i])!=0; i++){}
|
|
*tokenType = TOKEN_ID;
|
|
return i;
|
|
}
|
|
default: {
|
|
if( !IdChar(*z) ){
|
|
break;
|
|
}
|
|
for(i=1; IdChar(z[i]); i++){}
|
|
*tokenType = TOKEN_ID;
|
|
return i;
|
|
}
|
|
}
|
|
*tokenType = TOKEN_PUNCT;
|
|
return 1;
|
|
}
|
|
|
|
/*
|
|
** A token extracted from a string is an instance of the following
|
|
** structure.
|
|
*/
|
|
typedef struct Token {
|
|
const char *z; /* Pointer to token text. Not '\000' terminated */
|
|
short int n; /* Length of the token text in bytes. */
|
|
} Token;
|
|
|
|
/*
|
|
** Given a input string (which is really one of the argv[] parameters
|
|
** passed into xConnect or xCreate) split the string up into tokens.
|
|
** Return an array of pointers to '\000' terminated strings, one string
|
|
** for each non-whitespace token.
|
|
**
|
|
** The returned array is terminated by a single NULL pointer.
|
|
**
|
|
** Space to hold the returned array is obtained from a single
|
|
** malloc and should be freed by passing the return value to free().
|
|
** The individual strings within the token list are all a part of
|
|
** the single memory allocation and will all be freed at once.
|
|
*/
|
|
static char **tokenizeString(const char *z, int *pnToken){
|
|
int nToken = 0;
|
|
Token *aToken = malloc( strlen(z) * sizeof(aToken[0]) );
|
|
int n = 1;
|
|
int e, i;
|
|
int totalSize = 0;
|
|
char **azToken;
|
|
char *zCopy;
|
|
while( n>0 ){
|
|
n = getToken(z, &e);
|
|
if( e!=TOKEN_SPACE ){
|
|
aToken[nToken].z = z;
|
|
aToken[nToken].n = n;
|
|
nToken++;
|
|
totalSize += n+1;
|
|
}
|
|
z += n;
|
|
}
|
|
azToken = (char**)malloc( nToken*sizeof(char*) + totalSize );
|
|
zCopy = (char*)&azToken[nToken];
|
|
nToken--;
|
|
for(i=0; i<nToken; i++){
|
|
azToken[i] = zCopy;
|
|
n = aToken[i].n;
|
|
memcpy(zCopy, aToken[i].z, n);
|
|
zCopy[n] = 0;
|
|
zCopy += n+1;
|
|
}
|
|
azToken[nToken] = 0;
|
|
free(aToken);
|
|
*pnToken = nToken;
|
|
return azToken;
|
|
}
|
|
|
|
/*
|
|
** Convert an SQL-style quoted string into a normal string by removing
|
|
** the quote characters. The conversion is done in-place. If the
|
|
** input does not begin with a quote character, then this routine
|
|
** is a no-op.
|
|
**
|
|
** Examples:
|
|
**
|
|
** "abc" becomes abc
|
|
** 'xyz' becomes xyz
|
|
** [pqr] becomes pqr
|
|
** `mno` becomes mno
|
|
*/
|
|
static void dequoteString(char *z){
|
|
int quote;
|
|
int i, j;
|
|
if( z==0 ) return;
|
|
quote = z[0];
|
|
switch( quote ){
|
|
case '\'': break;
|
|
case '"': break;
|
|
case '`': break; /* For MySQL compatibility */
|
|
case '[': quote = ']'; break; /* For MS SqlServer compatibility */
|
|
default: return;
|
|
}
|
|
for(i=1, j=0; z[i]; i++){
|
|
if( z[i]==quote ){
|
|
if( z[i+1]==quote ){
|
|
z[j++] = quote;
|
|
i++;
|
|
}else{
|
|
z[j++] = 0;
|
|
break;
|
|
}
|
|
}else{
|
|
z[j++] = z[i];
|
|
}
|
|
}
|
|
}
|
|
|
|
/*
|
|
** The input azIn is a NULL-terminated list of tokens. Remove the first
|
|
** token and all punctuation tokens. Remove the quotes from
|
|
** around string literal tokens.
|
|
**
|
|
** Example:
|
|
**
|
|
** input: tokenize chinese ( 'simplifed' , 'mixed' )
|
|
** output: chinese simplifed mixed
|
|
**
|
|
** Another example:
|
|
**
|
|
** input: delimiters ( '[' , ']' , '...' )
|
|
** output: [ ] ...
|
|
*/
|
|
static void tokenListToIdList(char **azIn){
|
|
int i, j;
|
|
if( azIn ){
|
|
for(i=0, j=-1; azIn[i]; i++){
|
|
if( safe_isalnum(azIn[i][0]) || azIn[i][1] ){
|
|
dequoteString(azIn[i]);
|
|
if( j>=0 ){
|
|
azIn[j] = azIn[i];
|
|
}
|
|
j++;
|
|
}
|
|
}
|
|
azIn[j] = 0;
|
|
}
|
|
}
|
|
|
|
|
|
/*
|
|
** Find the first alphanumeric token in the string zIn. Null-terminate
|
|
** this token. Remove any quotation marks. And return a pointer to
|
|
** the result.
|
|
*/
|
|
static char *firstToken(char *zIn, char **pzTail){
|
|
int n, ttype;
|
|
while(1){
|
|
n = getToken(zIn, &ttype);
|
|
if( ttype==TOKEN_SPACE ){
|
|
zIn += n;
|
|
}else if( ttype==TOKEN_EOF ){
|
|
*pzTail = zIn;
|
|
return 0;
|
|
}else{
|
|
zIn[n] = 0;
|
|
*pzTail = &zIn[1];
|
|
dequoteString(zIn);
|
|
return zIn;
|
|
}
|
|
}
|
|
/*NOTREACHED*/
|
|
}
|
|
|
|
/* Return true if...
|
|
**
|
|
** * s begins with the string t, ignoring case
|
|
** * s is longer than t
|
|
** * The first character of s beyond t is not a alphanumeric
|
|
**
|
|
** Ignore leading space in *s.
|
|
**
|
|
** To put it another way, return true if the first token of
|
|
** s[] is t[].
|
|
*/
|
|
static int startsWith(const char *s, const char *t){
|
|
while( safe_isspace(*s) ){ s++; }
|
|
while( *t ){
|
|
if( safe_tolower(*s++)!=safe_tolower(*t++) ) return 0;
|
|
}
|
|
return *s!='_' && !safe_isalnum(*s);
|
|
}
|
|
|
|
/*
|
|
** An instance of this structure defines the "spec" of a
|
|
** full text index. This structure is populated by parseSpec
|
|
** and use by fulltextConnect and fulltextCreate.
|
|
*/
|
|
typedef struct TableSpec {
|
|
const char *zDb; /* Logical database name */
|
|
const char *zName; /* Name of the full-text index */
|
|
int nColumn; /* Number of columns to be indexed */
|
|
char **azColumn; /* Original names of columns to be indexed */
|
|
char **azContentColumn; /* Column names for %_content */
|
|
char **azTokenizer; /* Name of tokenizer and its arguments */
|
|
} TableSpec;
|
|
|
|
/*
|
|
** Reclaim all of the memory used by a TableSpec
|
|
*/
|
|
static void clearTableSpec(TableSpec *p) {
|
|
free(p->azColumn);
|
|
free(p->azContentColumn);
|
|
free(p->azTokenizer);
|
|
}
|
|
|
|
/* Parse a CREATE VIRTUAL TABLE statement, which looks like this:
|
|
*
|
|
* CREATE VIRTUAL TABLE email
|
|
* USING fts1(subject, body, tokenize mytokenizer(myarg))
|
|
*
|
|
* We return parsed information in a TableSpec structure.
|
|
*
|
|
*/
|
|
static int parseSpec(TableSpec *pSpec, int argc, const char *const*argv,
|
|
char**pzErr){
|
|
int i, n;
|
|
char *z, *zDummy;
|
|
char **azArg;
|
|
const char *zTokenizer = 0; /* argv[] entry describing the tokenizer */
|
|
|
|
assert( argc>=3 );
|
|
/* Current interface:
|
|
** argv[0] - module name
|
|
** argv[1] - database name
|
|
** argv[2] - table name
|
|
** argv[3..] - columns, optionally followed by tokenizer specification
|
|
** and snippet delimiters specification.
|
|
*/
|
|
|
|
/* Make a copy of the complete argv[][] array in a single allocation.
|
|
** The argv[][] array is read-only and transient. We can write to the
|
|
** copy in order to modify things and the copy is persistent.
|
|
*/
|
|
memset(pSpec, 0, sizeof(*pSpec));
|
|
for(i=n=0; i<argc; i++){
|
|
n += strlen(argv[i]) + 1;
|
|
}
|
|
azArg = malloc( sizeof(char*)*argc + n );
|
|
if( azArg==0 ){
|
|
return SQLITE_NOMEM;
|
|
}
|
|
z = (char*)&azArg[argc];
|
|
for(i=0; i<argc; i++){
|
|
azArg[i] = z;
|
|
strcpy(z, argv[i]);
|
|
z += strlen(z)+1;
|
|
}
|
|
|
|
/* Identify the column names and the tokenizer and delimiter arguments
|
|
** in the argv[][] array.
|
|
*/
|
|
pSpec->zDb = azArg[1];
|
|
pSpec->zName = azArg[2];
|
|
pSpec->nColumn = 0;
|
|
pSpec->azColumn = azArg;
|
|
zTokenizer = "tokenize simple";
|
|
for(i=3; i<argc; ++i){
|
|
if( startsWith(azArg[i],"tokenize") ){
|
|
zTokenizer = azArg[i];
|
|
}else{
|
|
z = azArg[pSpec->nColumn] = firstToken(azArg[i], &zDummy);
|
|
pSpec->nColumn++;
|
|
}
|
|
}
|
|
if( pSpec->nColumn==0 ){
|
|
azArg[0] = "content";
|
|
pSpec->nColumn = 1;
|
|
}
|
|
|
|
/*
|
|
** Construct the list of content column names.
|
|
**
|
|
** Each content column name will be of the form cNNAAAA
|
|
** where NN is the column number and AAAA is the sanitized
|
|
** column name. "sanitized" means that special characters are
|
|
** converted to "_". The cNN prefix guarantees that all column
|
|
** names are unique.
|
|
**
|
|
** The AAAA suffix is not strictly necessary. It is included
|
|
** for the convenience of people who might examine the generated
|
|
** %_content table and wonder what the columns are used for.
|
|
*/
|
|
pSpec->azContentColumn = malloc( pSpec->nColumn * sizeof(char *) );
|
|
if( pSpec->azContentColumn==0 ){
|
|
clearTableSpec(pSpec);
|
|
return SQLITE_NOMEM;
|
|
}
|
|
for(i=0; i<pSpec->nColumn; i++){
|
|
char *p;
|
|
pSpec->azContentColumn[i] = sqlite3_mprintf("c%d%s", i, azArg[i]);
|
|
for (p = pSpec->azContentColumn[i]; *p ; ++p) {
|
|
if( !safe_isalnum(*p) ) *p = '_';
|
|
}
|
|
}
|
|
|
|
/*
|
|
** Parse the tokenizer specification string.
|
|
*/
|
|
pSpec->azTokenizer = tokenizeString(zTokenizer, &n);
|
|
tokenListToIdList(pSpec->azTokenizer);
|
|
|
|
return SQLITE_OK;
|
|
}
|
|
|
|
/*
|
|
** Generate a CREATE TABLE statement that describes the schema of
|
|
** the virtual table. Return a pointer to this schema string.
|
|
**
|
|
** Space is obtained from sqlite3_mprintf() and should be freed
|
|
** using sqlite3_free().
|
|
*/
|
|
static char *fulltextSchema(
|
|
int nColumn, /* Number of columns */
|
|
const char *const* azColumn, /* List of columns */
|
|
const char *zTableName /* Name of the table */
|
|
){
|
|
int i;
|
|
char *zSchema, *zNext;
|
|
const char *zSep = "(";
|
|
zSchema = sqlite3_mprintf("CREATE TABLE x");
|
|
for(i=0; i<nColumn; i++){
|
|
zNext = sqlite3_mprintf("%s%s%Q", zSchema, zSep, azColumn[i]);
|
|
sqlite3_free(zSchema);
|
|
zSchema = zNext;
|
|
zSep = ",";
|
|
}
|
|
zNext = sqlite3_mprintf("%s,%Q)", zSchema, zTableName);
|
|
sqlite3_free(zSchema);
|
|
return zNext;
|
|
}
|
|
|
|
/*
|
|
** Build a new sqlite3_vtab structure that will describe the
|
|
** fulltext index defined by spec.
|
|
*/
|
|
static int constructVtab(
|
|
sqlite3 *db, /* The SQLite database connection */
|
|
TableSpec *spec, /* Parsed spec information from parseSpec() */
|
|
sqlite3_vtab **ppVTab, /* Write the resulting vtab structure here */
|
|
char **pzErr /* Write any error message here */
|
|
){
|
|
int rc;
|
|
int n;
|
|
fulltext_vtab *v = 0;
|
|
const sqlite3_tokenizer_module *m = NULL;
|
|
char *schema;
|
|
|
|
v = (fulltext_vtab *) malloc(sizeof(fulltext_vtab));
|
|
if( v==0 ) return SQLITE_NOMEM;
|
|
memset(v, 0, sizeof(*v));
|
|
/* sqlite will initialize v->base */
|
|
v->db = db;
|
|
v->zDb = spec->zDb; /* Freed when azColumn is freed */
|
|
v->zName = spec->zName; /* Freed when azColumn is freed */
|
|
v->nColumn = spec->nColumn;
|
|
v->azContentColumn = spec->azContentColumn;
|
|
spec->azContentColumn = 0;
|
|
v->azColumn = spec->azColumn;
|
|
spec->azColumn = 0;
|
|
|
|
if( spec->azTokenizer==0 ){
|
|
return SQLITE_NOMEM;
|
|
}
|
|
/* TODO(shess) For now, add new tokenizers as else if clauses. */
|
|
if( spec->azTokenizer[0]==0 || startsWith(spec->azTokenizer[0], "simple") ){
|
|
sqlite3Fts1SimpleTokenizerModule(&m);
|
|
}else if( startsWith(spec->azTokenizer[0], "porter") ){
|
|
sqlite3Fts1PorterTokenizerModule(&m);
|
|
}else{
|
|
*pzErr = sqlite3_mprintf("unknown tokenizer: %s", spec->azTokenizer[0]);
|
|
rc = SQLITE_ERROR;
|
|
goto err;
|
|
}
|
|
for(n=0; spec->azTokenizer[n]; n++){}
|
|
if( n ){
|
|
rc = m->xCreate(n-1, (const char*const*)&spec->azTokenizer[1],
|
|
&v->pTokenizer);
|
|
}else{
|
|
rc = m->xCreate(0, 0, &v->pTokenizer);
|
|
}
|
|
if( rc!=SQLITE_OK ) goto err;
|
|
v->pTokenizer->pModule = m;
|
|
|
|
/* TODO: verify the existence of backing tables foo_content, foo_term */
|
|
|
|
schema = fulltextSchema(v->nColumn, (const char*const*)v->azColumn,
|
|
spec->zName);
|
|
rc = sqlite3_declare_vtab(db, schema);
|
|
sqlite3_free(schema);
|
|
if( rc!=SQLITE_OK ) goto err;
|
|
|
|
memset(v->pFulltextStatements, 0, sizeof(v->pFulltextStatements));
|
|
|
|
*ppVTab = &v->base;
|
|
TRACE(("FTS1 Connect %p\n", v));
|
|
|
|
return rc;
|
|
|
|
err:
|
|
fulltext_vtab_destroy(v);
|
|
return rc;
|
|
}
|
|
|
|
static int fulltextConnect(
|
|
sqlite3 *db,
|
|
void *pAux,
|
|
int argc, const char *const*argv,
|
|
sqlite3_vtab **ppVTab,
|
|
char **pzErr
|
|
){
|
|
TableSpec spec;
|
|
int rc = parseSpec(&spec, argc, argv, pzErr);
|
|
if( rc!=SQLITE_OK ) return rc;
|
|
|
|
rc = constructVtab(db, &spec, ppVTab, pzErr);
|
|
clearTableSpec(&spec);
|
|
return rc;
|
|
}
|
|
|
|
/* The %_content table holds the text of each document, with
|
|
** the rowid used as the docid.
|
|
**
|
|
** The %_term table maps each term to a document list blob
|
|
** containing elements sorted by ascending docid, each element
|
|
** encoded as:
|
|
**
|
|
** docid varint-encoded
|
|
** token elements:
|
|
** position+1 varint-encoded as delta from previous position
|
|
** start offset varint-encoded as delta from previous start offset
|
|
** end offset varint-encoded as delta from start offset
|
|
**
|
|
** The sentinel position of 0 indicates the end of the token list.
|
|
**
|
|
** Additionally, doclist blobs are chunked into multiple segments,
|
|
** using segment to order the segments. New elements are added to
|
|
** the segment at segment 0, until it exceeds CHUNK_MAX. Then
|
|
** segment 0 is deleted, and the doclist is inserted at segment 1.
|
|
** If there is already a doclist at segment 1, the segment 0 doclist
|
|
** is merged with it, the segment 1 doclist is deleted, and the
|
|
** merged doclist is inserted at segment 2, repeating those
|
|
** operations until an insert succeeds.
|
|
**
|
|
** Since this structure doesn't allow us to update elements in place
|
|
** in case of deletion or update, these are simply written to
|
|
** segment 0 (with an empty token list in case of deletion), with
|
|
** docListAccumulate() taking care to retain lower-segment
|
|
** information in preference to higher-segment information.
|
|
*/
|
|
/* TODO(shess) Provide a VACUUM type operation which both removes
|
|
** deleted elements which are no longer necessary, and duplicated
|
|
** elements. I suspect this will probably not be necessary in
|
|
** practice, though.
|
|
*/
|
|
static int fulltextCreate(sqlite3 *db, void *pAux,
|
|
int argc, const char * const *argv,
|
|
sqlite3_vtab **ppVTab, char **pzErr){
|
|
int rc;
|
|
TableSpec spec;
|
|
StringBuffer schema;
|
|
TRACE(("FTS1 Create\n"));
|
|
|
|
rc = parseSpec(&spec, argc, argv, pzErr);
|
|
if( rc!=SQLITE_OK ) return rc;
|
|
|
|
initStringBuffer(&schema);
|
|
append(&schema, "CREATE TABLE %_content(");
|
|
appendList(&schema, spec.nColumn, spec.azContentColumn);
|
|
append(&schema, ")");
|
|
rc = sql_exec(db, spec.zDb, spec.zName, schema.s);
|
|
free(schema.s);
|
|
if( rc!=SQLITE_OK ) goto out;
|
|
|
|
rc = sql_exec(db, spec.zDb, spec.zName,
|
|
"create table %_term(term text, segment integer, doclist blob, "
|
|
"primary key(term, segment));");
|
|
if( rc!=SQLITE_OK ) goto out;
|
|
|
|
rc = constructVtab(db, &spec, ppVTab, pzErr);
|
|
|
|
out:
|
|
clearTableSpec(&spec);
|
|
return rc;
|
|
}
|
|
|
|
/* Decide how to handle an SQL query. */
|
|
static int fulltextBestIndex(sqlite3_vtab *pVTab, sqlite3_index_info *pInfo){
|
|
int i;
|
|
TRACE(("FTS1 BestIndex\n"));
|
|
|
|
for(i=0; i<pInfo->nConstraint; ++i){
|
|
const struct sqlite3_index_constraint *pConstraint;
|
|
pConstraint = &pInfo->aConstraint[i];
|
|
if( pConstraint->usable ) {
|
|
if( pConstraint->iColumn==-1 &&
|
|
pConstraint->op==SQLITE_INDEX_CONSTRAINT_EQ ){
|
|
pInfo->idxNum = QUERY_ROWID; /* lookup by rowid */
|
|
TRACE(("FTS1 QUERY_ROWID\n"));
|
|
} else if( pConstraint->iColumn>=0 &&
|
|
pConstraint->op==SQLITE_INDEX_CONSTRAINT_MATCH ){
|
|
/* full-text search */
|
|
pInfo->idxNum = QUERY_FULLTEXT + pConstraint->iColumn;
|
|
TRACE(("FTS1 QUERY_FULLTEXT %d\n", pConstraint->iColumn));
|
|
} else continue;
|
|
|
|
pInfo->aConstraintUsage[i].argvIndex = 1;
|
|
pInfo->aConstraintUsage[i].omit = 1;
|
|
|
|
/* An arbitrary value for now.
|
|
* TODO: Perhaps rowid matches should be considered cheaper than
|
|
* full-text searches. */
|
|
pInfo->estimatedCost = 1.0;
|
|
|
|
return SQLITE_OK;
|
|
}
|
|
}
|
|
pInfo->idxNum = QUERY_GENERIC;
|
|
return SQLITE_OK;
|
|
}
|
|
|
|
static int fulltextDisconnect(sqlite3_vtab *pVTab){
|
|
TRACE(("FTS1 Disconnect %p\n", pVTab));
|
|
fulltext_vtab_destroy((fulltext_vtab *)pVTab);
|
|
return SQLITE_OK;
|
|
}
|
|
|
|
static int fulltextDestroy(sqlite3_vtab *pVTab){
|
|
fulltext_vtab *v = (fulltext_vtab *)pVTab;
|
|
int rc;
|
|
|
|
TRACE(("FTS1 Destroy %p\n", pVTab));
|
|
rc = sql_exec(v->db, v->zDb, v->zName,
|
|
"drop table if exists %_content;"
|
|
"drop table if exists %_term;"
|
|
);
|
|
if( rc!=SQLITE_OK ) return rc;
|
|
|
|
fulltext_vtab_destroy((fulltext_vtab *)pVTab);
|
|
return SQLITE_OK;
|
|
}
|
|
|
|
static int fulltextOpen(sqlite3_vtab *pVTab, sqlite3_vtab_cursor **ppCursor){
|
|
fulltext_cursor *c;
|
|
|
|
c = (fulltext_cursor *) calloc(sizeof(fulltext_cursor), 1);
|
|
/* sqlite will initialize c->base */
|
|
*ppCursor = &c->base;
|
|
TRACE(("FTS1 Open %p: %p\n", pVTab, c));
|
|
|
|
return SQLITE_OK;
|
|
}
|
|
|
|
|
|
/* Free all of the dynamically allocated memory held by *q
|
|
*/
|
|
static void queryClear(Query *q){
|
|
int i;
|
|
for(i = 0; i < q->nTerms; ++i){
|
|
free(q->pTerms[i].pTerm);
|
|
}
|
|
free(q->pTerms);
|
|
memset(q, 0, sizeof(*q));
|
|
}
|
|
|
|
/* Free all of the dynamically allocated memory held by the
|
|
** Snippet
|
|
*/
|
|
static void snippetClear(Snippet *p){
|
|
free(p->aMatch);
|
|
free(p->zOffset);
|
|
free(p->zSnippet);
|
|
memset(p, 0, sizeof(*p));
|
|
}
|
|
/*
|
|
** Append a single entry to the p->aMatch[] log.
|
|
*/
|
|
static void snippetAppendMatch(
|
|
Snippet *p, /* Append the entry to this snippet */
|
|
int iCol, int iTerm, /* The column and query term */
|
|
int iStart, int nByte /* Offset and size of the match */
|
|
){
|
|
int i;
|
|
struct snippetMatch *pMatch;
|
|
if( p->nMatch+1>=p->nAlloc ){
|
|
p->nAlloc = p->nAlloc*2 + 10;
|
|
p->aMatch = realloc(p->aMatch, p->nAlloc*sizeof(p->aMatch[0]) );
|
|
if( p->aMatch==0 ){
|
|
p->nMatch = 0;
|
|
p->nAlloc = 0;
|
|
return;
|
|
}
|
|
}
|
|
i = p->nMatch++;
|
|
pMatch = &p->aMatch[i];
|
|
pMatch->iCol = iCol;
|
|
pMatch->iTerm = iTerm;
|
|
pMatch->iStart = iStart;
|
|
pMatch->nByte = nByte;
|
|
}
|
|
|
|
/*
|
|
** Sizing information for the circular buffer used in snippetOffsetsOfColumn()
|
|
*/
|
|
#define FTS1_ROTOR_SZ (32)
|
|
#define FTS1_ROTOR_MASK (FTS1_ROTOR_SZ-1)
|
|
|
|
/*
|
|
** Add entries to pSnippet->aMatch[] for every match that occurs against
|
|
** document zDoc[0..nDoc-1] which is stored in column iColumn.
|
|
*/
|
|
static void snippetOffsetsOfColumn(
|
|
Query *pQuery,
|
|
Snippet *pSnippet,
|
|
int iColumn,
|
|
const char *zDoc,
|
|
int nDoc
|
|
){
|
|
const sqlite3_tokenizer_module *pTModule; /* The tokenizer module */
|
|
sqlite3_tokenizer *pTokenizer; /* The specific tokenizer */
|
|
sqlite3_tokenizer_cursor *pTCursor; /* Tokenizer cursor */
|
|
fulltext_vtab *pVtab; /* The full text index */
|
|
int nColumn; /* Number of columns in the index */
|
|
const QueryTerm *aTerm; /* Query string terms */
|
|
int nTerm; /* Number of query string terms */
|
|
int i, j; /* Loop counters */
|
|
int rc; /* Return code */
|
|
unsigned int match, prevMatch; /* Phrase search bitmasks */
|
|
const char *zToken; /* Next token from the tokenizer */
|
|
int nToken; /* Size of zToken */
|
|
int iBegin, iEnd, iPos; /* Offsets of beginning and end */
|
|
|
|
/* The following variables keep a circular buffer of the last
|
|
** few tokens */
|
|
unsigned int iRotor = 0; /* Index of current token */
|
|
int iRotorBegin[FTS1_ROTOR_SZ]; /* Beginning offset of token */
|
|
int iRotorLen[FTS1_ROTOR_SZ]; /* Length of token */
|
|
|
|
pVtab = pQuery->pFts;
|
|
nColumn = pVtab->nColumn;
|
|
pTokenizer = pVtab->pTokenizer;
|
|
pTModule = pTokenizer->pModule;
|
|
rc = pTModule->xOpen(pTokenizer, zDoc, nDoc, &pTCursor);
|
|
if( rc ) return;
|
|
pTCursor->pTokenizer = pTokenizer;
|
|
aTerm = pQuery->pTerms;
|
|
nTerm = pQuery->nTerms;
|
|
if( nTerm>=FTS1_ROTOR_SZ ){
|
|
nTerm = FTS1_ROTOR_SZ - 1;
|
|
}
|
|
prevMatch = 0;
|
|
while(1){
|
|
rc = pTModule->xNext(pTCursor, &zToken, &nToken, &iBegin, &iEnd, &iPos);
|
|
if( rc ) break;
|
|
iRotorBegin[iRotor&FTS1_ROTOR_MASK] = iBegin;
|
|
iRotorLen[iRotor&FTS1_ROTOR_MASK] = iEnd-iBegin;
|
|
match = 0;
|
|
for(i=0; i<nTerm; i++){
|
|
int iCol;
|
|
iCol = aTerm[i].iColumn;
|
|
if( iCol>=0 && iCol<nColumn && iCol!=iColumn ) continue;
|
|
if( aTerm[i].nTerm!=nToken ) continue;
|
|
if( memcmp(aTerm[i].pTerm, zToken, nToken) ) continue;
|
|
if( aTerm[i].iPhrase>1 && (prevMatch & (1<<i))==0 ) continue;
|
|
match |= 1<<i;
|
|
if( i==nTerm-1 || aTerm[i+1].iPhrase==1 ){
|
|
for(j=aTerm[i].iPhrase-1; j>=0; j--){
|
|
int k = (iRotor-j) & FTS1_ROTOR_MASK;
|
|
snippetAppendMatch(pSnippet, iColumn, i-j,
|
|
iRotorBegin[k], iRotorLen[k]);
|
|
}
|
|
}
|
|
}
|
|
prevMatch = match<<1;
|
|
iRotor++;
|
|
}
|
|
pTModule->xClose(pTCursor);
|
|
}
|
|
|
|
|
|
/*
|
|
** Compute all offsets for the current row of the query.
|
|
** If the offsets have already been computed, this routine is a no-op.
|
|
*/
|
|
static void snippetAllOffsets(fulltext_cursor *p){
|
|
int nColumn;
|
|
int iColumn, i;
|
|
int iFirst, iLast;
|
|
fulltext_vtab *pFts;
|
|
|
|
if( p->snippet.nMatch ) return;
|
|
if( p->q.nTerms==0 ) return;
|
|
pFts = p->q.pFts;
|
|
nColumn = pFts->nColumn;
|
|
iColumn = p->iCursorType - QUERY_FULLTEXT;
|
|
if( iColumn<0 || iColumn>=nColumn ){
|
|
iFirst = 0;
|
|
iLast = nColumn-1;
|
|
}else{
|
|
iFirst = iColumn;
|
|
iLast = iColumn;
|
|
}
|
|
for(i=iFirst; i<=iLast; i++){
|
|
const char *zDoc;
|
|
int nDoc;
|
|
zDoc = (const char*)sqlite3_column_text(p->pStmt, i+1);
|
|
nDoc = sqlite3_column_bytes(p->pStmt, i+1);
|
|
snippetOffsetsOfColumn(&p->q, &p->snippet, i, zDoc, nDoc);
|
|
}
|
|
}
|
|
|
|
/*
|
|
** Convert the information in the aMatch[] array of the snippet
|
|
** into the string zOffset[0..nOffset-1].
|
|
*/
|
|
static void snippetOffsetText(Snippet *p){
|
|
int i;
|
|
int cnt = 0;
|
|
StringBuffer sb;
|
|
char zBuf[200];
|
|
if( p->zOffset ) return;
|
|
initStringBuffer(&sb);
|
|
for(i=0; i<p->nMatch; i++){
|
|
struct snippetMatch *pMatch = &p->aMatch[i];
|
|
zBuf[0] = ' ';
|
|
sqlite3_snprintf(sizeof(zBuf)-1, &zBuf[cnt>0], "%d %d %d %d",
|
|
pMatch->iCol, pMatch->iTerm, pMatch->iStart, pMatch->nByte);
|
|
append(&sb, zBuf);
|
|
cnt++;
|
|
}
|
|
p->zOffset = sb.s;
|
|
p->nOffset = sb.len;
|
|
}
|
|
|
|
/*
|
|
** zDoc[0..nDoc-1] is phrase of text. aMatch[0..nMatch-1] are a set
|
|
** of matching words some of which might be in zDoc. zDoc is column
|
|
** number iCol.
|
|
**
|
|
** iBreak is suggested spot in zDoc where we could begin or end an
|
|
** excerpt. Return a value similar to iBreak but possibly adjusted
|
|
** to be a little left or right so that the break point is better.
|
|
*/
|
|
static int wordBoundary(
|
|
int iBreak, /* The suggested break point */
|
|
const char *zDoc, /* Document text */
|
|
int nDoc, /* Number of bytes in zDoc[] */
|
|
struct snippetMatch *aMatch, /* Matching words */
|
|
int nMatch, /* Number of entries in aMatch[] */
|
|
int iCol /* The column number for zDoc[] */
|
|
){
|
|
int i;
|
|
if( iBreak<=10 ){
|
|
return 0;
|
|
}
|
|
if( iBreak>=nDoc-10 ){
|
|
return nDoc;
|
|
}
|
|
for(i=0; i<nMatch && aMatch[i].iCol<iCol; i++){}
|
|
while( i<nMatch && aMatch[i].iStart+aMatch[i].nByte<iBreak ){ i++; }
|
|
if( i<nMatch ){
|
|
if( aMatch[i].iStart<iBreak+10 ){
|
|
return aMatch[i].iStart;
|
|
}
|
|
if( i>0 && aMatch[i-1].iStart+aMatch[i-1].nByte>=iBreak ){
|
|
return aMatch[i-1].iStart;
|
|
}
|
|
}
|
|
for(i=1; i<=10; i++){
|
|
if( safe_isspace(zDoc[iBreak-i]) ){
|
|
return iBreak - i + 1;
|
|
}
|
|
if( safe_isspace(zDoc[iBreak+i]) ){
|
|
return iBreak + i + 1;
|
|
}
|
|
}
|
|
return iBreak;
|
|
}
|
|
|
|
/*
|
|
** If the StringBuffer does not end in white space, add a single
|
|
** space character to the end.
|
|
*/
|
|
static void appendWhiteSpace(StringBuffer *p){
|
|
if( p->len==0 ) return;
|
|
if( safe_isspace(p->s[p->len-1]) ) return;
|
|
append(p, " ");
|
|
}
|
|
|
|
/*
|
|
** Remove white space from teh end of the StringBuffer
|
|
*/
|
|
static void trimWhiteSpace(StringBuffer *p){
|
|
while( p->len>0 && safe_isspace(p->s[p->len-1]) ){
|
|
p->len--;
|
|
}
|
|
}
|
|
|
|
|
|
|
|
/*
|
|
** Allowed values for Snippet.aMatch[].snStatus
|
|
*/
|
|
#define SNIPPET_IGNORE 0 /* It is ok to omit this match from the snippet */
|
|
#define SNIPPET_DESIRED 1 /* We want to include this match in the snippet */
|
|
|
|
/*
|
|
** Generate the text of a snippet.
|
|
*/
|
|
static void snippetText(
|
|
fulltext_cursor *pCursor, /* The cursor we need the snippet for */
|
|
const char *zStartMark, /* Markup to appear before each match */
|
|
const char *zEndMark, /* Markup to appear after each match */
|
|
const char *zEllipsis /* Ellipsis mark */
|
|
){
|
|
int i, j;
|
|
struct snippetMatch *aMatch;
|
|
int nMatch;
|
|
int nDesired;
|
|
StringBuffer sb;
|
|
int tailCol;
|
|
int tailOffset;
|
|
int iCol;
|
|
int nDoc;
|
|
const char *zDoc;
|
|
int iStart, iEnd;
|
|
int tailEllipsis = 0;
|
|
int iMatch;
|
|
|
|
|
|
free(pCursor->snippet.zSnippet);
|
|
pCursor->snippet.zSnippet = 0;
|
|
aMatch = pCursor->snippet.aMatch;
|
|
nMatch = pCursor->snippet.nMatch;
|
|
initStringBuffer(&sb);
|
|
|
|
for(i=0; i<nMatch; i++){
|
|
aMatch[i].snStatus = SNIPPET_IGNORE;
|
|
}
|
|
nDesired = 0;
|
|
for(i=0; i<pCursor->q.nTerms; i++){
|
|
for(j=0; j<nMatch; j++){
|
|
if( aMatch[j].iTerm==i ){
|
|
aMatch[j].snStatus = SNIPPET_DESIRED;
|
|
nDesired++;
|
|
break;
|
|
}
|
|
}
|
|
}
|
|
|
|
iMatch = 0;
|
|
tailCol = -1;
|
|
tailOffset = 0;
|
|
for(i=0; i<nMatch && nDesired>0; i++){
|
|
if( aMatch[i].snStatus!=SNIPPET_DESIRED ) continue;
|
|
nDesired--;
|
|
iCol = aMatch[i].iCol;
|
|
zDoc = (const char*)sqlite3_column_text(pCursor->pStmt, iCol+1);
|
|
nDoc = sqlite3_column_bytes(pCursor->pStmt, iCol+1);
|
|
iStart = aMatch[i].iStart - 40;
|
|
iStart = wordBoundary(iStart, zDoc, nDoc, aMatch, nMatch, iCol);
|
|
if( iStart<=10 ){
|
|
iStart = 0;
|
|
}
|
|
if( iCol==tailCol && iStart<=tailOffset+20 ){
|
|
iStart = tailOffset;
|
|
}
|
|
if( (iCol!=tailCol && tailCol>=0) || iStart!=tailOffset ){
|
|
trimWhiteSpace(&sb);
|
|
appendWhiteSpace(&sb);
|
|
append(&sb, zEllipsis);
|
|
appendWhiteSpace(&sb);
|
|
}
|
|
iEnd = aMatch[i].iStart + aMatch[i].nByte + 40;
|
|
iEnd = wordBoundary(iEnd, zDoc, nDoc, aMatch, nMatch, iCol);
|
|
if( iEnd>=nDoc-10 ){
|
|
iEnd = nDoc;
|
|
tailEllipsis = 0;
|
|
}else{
|
|
tailEllipsis = 1;
|
|
}
|
|
while( iMatch<nMatch && aMatch[iMatch].iCol<iCol ){ iMatch++; }
|
|
while( iStart<iEnd ){
|
|
while( iMatch<nMatch && aMatch[iMatch].iStart<iStart
|
|
&& aMatch[iMatch].iCol<=iCol ){
|
|
iMatch++;
|
|
}
|
|
if( iMatch<nMatch && aMatch[iMatch].iStart<iEnd
|
|
&& aMatch[iMatch].iCol==iCol ){
|
|
nappend(&sb, &zDoc[iStart], aMatch[iMatch].iStart - iStart);
|
|
iStart = aMatch[iMatch].iStart;
|
|
append(&sb, zStartMark);
|
|
nappend(&sb, &zDoc[iStart], aMatch[iMatch].nByte);
|
|
append(&sb, zEndMark);
|
|
iStart += aMatch[iMatch].nByte;
|
|
for(j=iMatch+1; j<nMatch; j++){
|
|
if( aMatch[j].iTerm==aMatch[iMatch].iTerm
|
|
&& aMatch[j].snStatus==SNIPPET_DESIRED ){
|
|
nDesired--;
|
|
aMatch[j].snStatus = SNIPPET_IGNORE;
|
|
}
|
|
}
|
|
}else{
|
|
nappend(&sb, &zDoc[iStart], iEnd - iStart);
|
|
iStart = iEnd;
|
|
}
|
|
}
|
|
tailCol = iCol;
|
|
tailOffset = iEnd;
|
|
}
|
|
trimWhiteSpace(&sb);
|
|
if( tailEllipsis ){
|
|
appendWhiteSpace(&sb);
|
|
append(&sb, zEllipsis);
|
|
}
|
|
pCursor->snippet.zSnippet = sb.s;
|
|
pCursor->snippet.nSnippet = sb.len;
|
|
}
|
|
|
|
|
|
/*
|
|
** Close the cursor. For additional information see the documentation
|
|
** on the xClose method of the virtual table interface.
|
|
*/
|
|
static int fulltextClose(sqlite3_vtab_cursor *pCursor){
|
|
fulltext_cursor *c = (fulltext_cursor *) pCursor;
|
|
TRACE(("FTS1 Close %p\n", c));
|
|
sqlite3_finalize(c->pStmt);
|
|
queryClear(&c->q);
|
|
snippetClear(&c->snippet);
|
|
if( c->result.pDoclist!=NULL ){
|
|
docListDelete(c->result.pDoclist);
|
|
}
|
|
free(c);
|
|
return SQLITE_OK;
|
|
}
|
|
|
|
static int fulltextNext(sqlite3_vtab_cursor *pCursor){
|
|
fulltext_cursor *c = (fulltext_cursor *) pCursor;
|
|
sqlite_int64 iDocid;
|
|
int rc;
|
|
|
|
TRACE(("FTS1 Next %p\n", pCursor));
|
|
snippetClear(&c->snippet);
|
|
if( c->iCursorType < QUERY_FULLTEXT ){
|
|
/* TODO(shess) Handle SQLITE_SCHEMA AND SQLITE_BUSY. */
|
|
rc = sqlite3_step(c->pStmt);
|
|
switch( rc ){
|
|
case SQLITE_ROW:
|
|
c->eof = 0;
|
|
return SQLITE_OK;
|
|
case SQLITE_DONE:
|
|
c->eof = 1;
|
|
return SQLITE_OK;
|
|
default:
|
|
c->eof = 1;
|
|
return rc;
|
|
}
|
|
} else { /* full-text query */
|
|
rc = sqlite3_reset(c->pStmt);
|
|
if( rc!=SQLITE_OK ) return rc;
|
|
|
|
iDocid = nextDocid(&c->result);
|
|
if( iDocid==0 ){
|
|
c->eof = 1;
|
|
return SQLITE_OK;
|
|
}
|
|
rc = sqlite3_bind_int64(c->pStmt, 1, iDocid);
|
|
if( rc!=SQLITE_OK ) return rc;
|
|
/* TODO(shess) Handle SQLITE_SCHEMA AND SQLITE_BUSY. */
|
|
rc = sqlite3_step(c->pStmt);
|
|
if( rc==SQLITE_ROW ){ /* the case we expect */
|
|
c->eof = 0;
|
|
return SQLITE_OK;
|
|
}
|
|
/* an error occurred; abort */
|
|
return rc==SQLITE_DONE ? SQLITE_ERROR : rc;
|
|
}
|
|
}
|
|
|
|
|
|
/* Return a DocList corresponding to the query term *pTerm. If *pTerm
|
|
** is the first term of a phrase query, go ahead and evaluate the phrase
|
|
** query and return the doclist for the entire phrase query.
|
|
**
|
|
** The result is stored in pTerm->doclist.
|
|
*/
|
|
static int docListOfTerm(
|
|
fulltext_vtab *v, /* The full text index */
|
|
int iColumn, /* column to restrict to. No restrition if >=nColumn */
|
|
QueryTerm *pQTerm, /* Term we are looking for, or 1st term of a phrase */
|
|
DocList **ppResult /* Write the result here */
|
|
){
|
|
DocList *pLeft, *pRight, *pNew;
|
|
int i, rc;
|
|
|
|
pLeft = docListNew(DL_POSITIONS);
|
|
rc = term_select_all(v, iColumn, pQTerm->pTerm, pQTerm->nTerm, pLeft);
|
|
if( rc ){
|
|
docListDelete(pLeft);
|
|
return rc;
|
|
}
|
|
for(i=1; i<=pQTerm->nPhrase; i++){
|
|
pRight = docListNew(DL_POSITIONS);
|
|
rc = term_select_all(v, iColumn, pQTerm[i].pTerm, pQTerm[i].nTerm, pRight);
|
|
if( rc ){
|
|
docListDelete(pLeft);
|
|
return rc;
|
|
}
|
|
pNew = docListNew(i<pQTerm->nPhrase ? DL_POSITIONS : DL_DOCIDS);
|
|
docListPhraseMerge(pLeft, pRight, pNew);
|
|
docListDelete(pLeft);
|
|
docListDelete(pRight);
|
|
pLeft = pNew;
|
|
}
|
|
*ppResult = pLeft;
|
|
return SQLITE_OK;
|
|
}
|
|
|
|
/* Add a new term pTerm[0..nTerm-1] to the query *q.
|
|
*/
|
|
static void queryAdd(Query *q, const char *pTerm, int nTerm){
|
|
QueryTerm *t;
|
|
++q->nTerms;
|
|
q->pTerms = realloc(q->pTerms, q->nTerms * sizeof(q->pTerms[0]));
|
|
if( q->pTerms==0 ){
|
|
q->nTerms = 0;
|
|
return;
|
|
}
|
|
t = &q->pTerms[q->nTerms - 1];
|
|
memset(t, 0, sizeof(*t));
|
|
t->pTerm = malloc(nTerm+1);
|
|
memcpy(t->pTerm, pTerm, nTerm);
|
|
t->pTerm[nTerm] = 0;
|
|
t->nTerm = nTerm;
|
|
t->isOr = q->nextIsOr;
|
|
q->nextIsOr = 0;
|
|
t->iColumn = q->nextColumn;
|
|
q->nextColumn = q->dfltColumn;
|
|
}
|
|
|
|
/*
|
|
** Check to see if the string zToken[0...nToken-1] matches any
|
|
** column name in the virtual table. If it does,
|
|
** return the zero-indexed column number. If not, return -1.
|
|
*/
|
|
static int checkColumnSpecifier(
|
|
fulltext_vtab *pVtab, /* The virtual table */
|
|
const char *zToken, /* Text of the token */
|
|
int nToken /* Number of characters in the token */
|
|
){
|
|
int i;
|
|
for(i=0; i<pVtab->nColumn; i++){
|
|
if( memcmp(pVtab->azColumn[i], zToken, nToken)==0
|
|
&& pVtab->azColumn[i][nToken]==0 ){
|
|
return i;
|
|
}
|
|
}
|
|
return -1;
|
|
}
|
|
|
|
/*
|
|
** Parse the text at pSegment[0..nSegment-1]. Add additional terms
|
|
** to the query being assemblied in pQuery.
|
|
**
|
|
** inPhrase is true if pSegment[0..nSegement-1] is contained within
|
|
** double-quotes. If inPhrase is true, then the first term
|
|
** is marked with the number of terms in the phrase less one and
|
|
** OR and "-" syntax is ignored. If inPhrase is false, then every
|
|
** term found is marked with nPhrase=0 and OR and "-" syntax is significant.
|
|
*/
|
|
static int tokenizeSegment(
|
|
sqlite3_tokenizer *pTokenizer, /* The tokenizer to use */
|
|
const char *pSegment, int nSegment, /* Query expression being parsed */
|
|
int inPhrase, /* True if within "..." */
|
|
Query *pQuery /* Append results here */
|
|
){
|
|
const sqlite3_tokenizer_module *pModule = pTokenizer->pModule;
|
|
sqlite3_tokenizer_cursor *pCursor;
|
|
int firstIndex = pQuery->nTerms;
|
|
int iCol;
|
|
int nTerm = 1;
|
|
|
|
int rc = pModule->xOpen(pTokenizer, pSegment, nSegment, &pCursor);
|
|
if( rc!=SQLITE_OK ) return rc;
|
|
pCursor->pTokenizer = pTokenizer;
|
|
|
|
while( 1 ){
|
|
const char *pToken;
|
|
int nToken, iBegin, iEnd, iPos;
|
|
|
|
rc = pModule->xNext(pCursor,
|
|
&pToken, &nToken,
|
|
&iBegin, &iEnd, &iPos);
|
|
if( rc!=SQLITE_OK ) break;
|
|
if( !inPhrase &&
|
|
pSegment[iEnd]==':' &&
|
|
(iCol = checkColumnSpecifier(pQuery->pFts, pToken, nToken))>=0 ){
|
|
pQuery->nextColumn = iCol;
|
|
continue;
|
|
}
|
|
if( !inPhrase && pQuery->nTerms>0 && nToken==2
|
|
&& pSegment[iBegin]=='O' && pSegment[iBegin+1]=='R' ){
|
|
pQuery->nextIsOr = 1;
|
|
continue;
|
|
}
|
|
queryAdd(pQuery, pToken, nToken);
|
|
if( !inPhrase && iBegin>0 && pSegment[iBegin-1]=='-' ){
|
|
pQuery->pTerms[pQuery->nTerms-1].isNot = 1;
|
|
}
|
|
pQuery->pTerms[pQuery->nTerms-1].iPhrase = nTerm;
|
|
if( inPhrase ){
|
|
nTerm++;
|
|
}
|
|
}
|
|
|
|
if( inPhrase && pQuery->nTerms>firstIndex ){
|
|
pQuery->pTerms[firstIndex].nPhrase = pQuery->nTerms - firstIndex - 1;
|
|
}
|
|
|
|
return pModule->xClose(pCursor);
|
|
}
|
|
|
|
/* Parse a query string, yielding a Query object pQuery.
|
|
**
|
|
** The calling function will need to queryClear() to clean up
|
|
** the dynamically allocated memory held by pQuery.
|
|
*/
|
|
static int parseQuery(
|
|
fulltext_vtab *v, /* The fulltext index */
|
|
const char *zInput, /* Input text of the query string */
|
|
int nInput, /* Size of the input text */
|
|
int dfltColumn, /* Default column of the index to match against */
|
|
Query *pQuery /* Write the parse results here. */
|
|
){
|
|
int iInput, inPhrase = 0;
|
|
|
|
if( zInput==0 ) nInput = 0;
|
|
if( nInput<0 ) nInput = strlen(zInput);
|
|
pQuery->nTerms = 0;
|
|
pQuery->pTerms = NULL;
|
|
pQuery->nextIsOr = 0;
|
|
pQuery->nextColumn = dfltColumn;
|
|
pQuery->dfltColumn = dfltColumn;
|
|
pQuery->pFts = v;
|
|
|
|
for(iInput=0; iInput<nInput; ++iInput){
|
|
int i;
|
|
for(i=iInput; i<nInput && zInput[i]!='"'; ++i){}
|
|
if( i>iInput ){
|
|
tokenizeSegment(v->pTokenizer, zInput+iInput, i-iInput, inPhrase,
|
|
pQuery);
|
|
}
|
|
iInput = i;
|
|
if( i<nInput ){
|
|
assert( zInput[i]=='"' );
|
|
inPhrase = !inPhrase;
|
|
}
|
|
}
|
|
|
|
if( inPhrase ){
|
|
/* unmatched quote */
|
|
queryClear(pQuery);
|
|
return SQLITE_ERROR;
|
|
}
|
|
return SQLITE_OK;
|
|
}
|
|
|
|
/* Perform a full-text query using the search expression in
|
|
** zInput[0..nInput-1]. Return a list of matching documents
|
|
** in pResult.
|
|
**
|
|
** Queries must match column iColumn. Or if iColumn>=nColumn
|
|
** they are allowed to match against any column.
|
|
*/
|
|
static int fulltextQuery(
|
|
fulltext_vtab *v, /* The full text index */
|
|
int iColumn, /* Match against this column by default */
|
|
const char *zInput, /* The query string */
|
|
int nInput, /* Number of bytes in zInput[] */
|
|
DocList **pResult, /* Write the result doclist here */
|
|
Query *pQuery /* Put parsed query string here */
|
|
){
|
|
int i, iNext, rc;
|
|
DocList *pLeft = NULL;
|
|
DocList *pRight, *pNew, *pOr;
|
|
int nNot = 0;
|
|
QueryTerm *aTerm;
|
|
|
|
rc = parseQuery(v, zInput, nInput, iColumn, pQuery);
|
|
if( rc!=SQLITE_OK ) return rc;
|
|
|
|
/* Merge AND terms. */
|
|
aTerm = pQuery->pTerms;
|
|
for(i = 0; i<pQuery->nTerms; i=iNext){
|
|
if( aTerm[i].isNot ){
|
|
/* Handle all NOT terms in a separate pass */
|
|
nNot++;
|
|
iNext = i + aTerm[i].nPhrase+1;
|
|
continue;
|
|
}
|
|
iNext = i + aTerm[i].nPhrase + 1;
|
|
rc = docListOfTerm(v, aTerm[i].iColumn, &aTerm[i], &pRight);
|
|
if( rc ){
|
|
queryClear(pQuery);
|
|
return rc;
|
|
}
|
|
while( iNext<pQuery->nTerms && aTerm[iNext].isOr ){
|
|
rc = docListOfTerm(v, aTerm[iNext].iColumn, &aTerm[iNext], &pOr);
|
|
iNext += aTerm[iNext].nPhrase + 1;
|
|
if( rc ){
|
|
queryClear(pQuery);
|
|
return rc;
|
|
}
|
|
pNew = docListNew(DL_DOCIDS);
|
|
docListOrMerge(pRight, pOr, pNew);
|
|
docListDelete(pRight);
|
|
docListDelete(pOr);
|
|
pRight = pNew;
|
|
}
|
|
if( pLeft==0 ){
|
|
pLeft = pRight;
|
|
}else{
|
|
pNew = docListNew(DL_DOCIDS);
|
|
docListAndMerge(pLeft, pRight, pNew);
|
|
docListDelete(pRight);
|
|
docListDelete(pLeft);
|
|
pLeft = pNew;
|
|
}
|
|
}
|
|
|
|
if( nNot && pLeft==0 ){
|
|
/* We do not yet know how to handle a query of only NOT terms */
|
|
return SQLITE_ERROR;
|
|
}
|
|
|
|
/* Do the EXCEPT terms */
|
|
for(i=0; i<pQuery->nTerms; i += aTerm[i].nPhrase + 1){
|
|
if( !aTerm[i].isNot ) continue;
|
|
rc = docListOfTerm(v, aTerm[i].iColumn, &aTerm[i], &pRight);
|
|
if( rc ){
|
|
queryClear(pQuery);
|
|
docListDelete(pLeft);
|
|
return rc;
|
|
}
|
|
pNew = docListNew(DL_DOCIDS);
|
|
docListExceptMerge(pLeft, pRight, pNew);
|
|
docListDelete(pRight);
|
|
docListDelete(pLeft);
|
|
pLeft = pNew;
|
|
}
|
|
|
|
*pResult = pLeft;
|
|
return rc;
|
|
}
|
|
|
|
/*
|
|
** This is the xFilter interface for the virtual table. See
|
|
** the virtual table xFilter method documentation for additional
|
|
** information.
|
|
**
|
|
** If idxNum==QUERY_GENERIC then do a full table scan against
|
|
** the %_content table.
|
|
**
|
|
** If idxNum==QUERY_ROWID then do a rowid lookup for a single entry
|
|
** in the %_content table.
|
|
**
|
|
** If idxNum>=QUERY_FULLTEXT then use the full text index. The
|
|
** column on the left-hand side of the MATCH operator is column
|
|
** number idxNum-QUERY_FULLTEXT, 0 indexed. argv[0] is the right-hand
|
|
** side of the MATCH operator.
|
|
*/
|
|
/* TODO(shess) Upgrade the cursor initialization and destruction to
|
|
** account for fulltextFilter() being called multiple times on the
|
|
** same cursor. The current solution is very fragile. Apply fix to
|
|
** fts2 as appropriate.
|
|
*/
|
|
static int fulltextFilter(
|
|
sqlite3_vtab_cursor *pCursor, /* The cursor used for this query */
|
|
int idxNum, const char *idxStr, /* Which indexing scheme to use */
|
|
int argc, sqlite3_value **argv /* Arguments for the indexing scheme */
|
|
){
|
|
fulltext_cursor *c = (fulltext_cursor *) pCursor;
|
|
fulltext_vtab *v = cursor_vtab(c);
|
|
int rc;
|
|
char *zSql;
|
|
|
|
TRACE(("FTS1 Filter %p\n",pCursor));
|
|
|
|
zSql = sqlite3_mprintf("select rowid, * from %%_content %s",
|
|
idxNum==QUERY_GENERIC ? "" : "where rowid=?");
|
|
sqlite3_finalize(c->pStmt);
|
|
rc = sql_prepare(v->db, v->zDb, v->zName, &c->pStmt, zSql);
|
|
sqlite3_free(zSql);
|
|
if( rc!=SQLITE_OK ) return rc;
|
|
|
|
c->iCursorType = idxNum;
|
|
switch( idxNum ){
|
|
case QUERY_GENERIC:
|
|
break;
|
|
|
|
case QUERY_ROWID:
|
|
rc = sqlite3_bind_int64(c->pStmt, 1, sqlite3_value_int64(argv[0]));
|
|
if( rc!=SQLITE_OK ) return rc;
|
|
break;
|
|
|
|
default: /* full-text search */
|
|
{
|
|
const char *zQuery = (const char *)sqlite3_value_text(argv[0]);
|
|
DocList *pResult;
|
|
assert( idxNum<=QUERY_FULLTEXT+v->nColumn);
|
|
assert( argc==1 );
|
|
queryClear(&c->q);
|
|
rc = fulltextQuery(v, idxNum-QUERY_FULLTEXT, zQuery, -1, &pResult, &c->q);
|
|
if( rc!=SQLITE_OK ) return rc;
|
|
if( c->result.pDoclist!=NULL ) docListDelete(c->result.pDoclist);
|
|
readerInit(&c->result, pResult);
|
|
break;
|
|
}
|
|
}
|
|
|
|
return fulltextNext(pCursor);
|
|
}
|
|
|
|
/* This is the xEof method of the virtual table. The SQLite core
|
|
** calls this routine to find out if it has reached the end of
|
|
** a query's results set.
|
|
*/
|
|
static int fulltextEof(sqlite3_vtab_cursor *pCursor){
|
|
fulltext_cursor *c = (fulltext_cursor *) pCursor;
|
|
return c->eof;
|
|
}
|
|
|
|
/* This is the xColumn method of the virtual table. The SQLite
|
|
** core calls this method during a query when it needs the value
|
|
** of a column from the virtual table. This method needs to use
|
|
** one of the sqlite3_result_*() routines to store the requested
|
|
** value back in the pContext.
|
|
*/
|
|
static int fulltextColumn(sqlite3_vtab_cursor *pCursor,
|
|
sqlite3_context *pContext, int idxCol){
|
|
fulltext_cursor *c = (fulltext_cursor *) pCursor;
|
|
fulltext_vtab *v = cursor_vtab(c);
|
|
|
|
if( idxCol<v->nColumn ){
|
|
sqlite3_value *pVal = sqlite3_column_value(c->pStmt, idxCol+1);
|
|
sqlite3_result_value(pContext, pVal);
|
|
}else if( idxCol==v->nColumn ){
|
|
/* The extra column whose name is the same as the table.
|
|
** Return a blob which is a pointer to the cursor
|
|
*/
|
|
sqlite3_result_blob(pContext, &c, sizeof(c), SQLITE_TRANSIENT);
|
|
}
|
|
return SQLITE_OK;
|
|
}
|
|
|
|
/* This is the xRowid method. The SQLite core calls this routine to
|
|
** retrive the rowid for the current row of the result set. The
|
|
** rowid should be written to *pRowid.
|
|
*/
|
|
static int fulltextRowid(sqlite3_vtab_cursor *pCursor, sqlite_int64 *pRowid){
|
|
fulltext_cursor *c = (fulltext_cursor *) pCursor;
|
|
|
|
*pRowid = sqlite3_column_int64(c->pStmt, 0);
|
|
return SQLITE_OK;
|
|
}
|
|
|
|
/* Add all terms in [zText] to the given hash table. If [iColumn] > 0,
|
|
* we also store positions and offsets in the hash table using the given
|
|
* column number. */
|
|
static int buildTerms(fulltext_vtab *v, fts1Hash *terms, sqlite_int64 iDocid,
|
|
const char *zText, int iColumn){
|
|
sqlite3_tokenizer *pTokenizer = v->pTokenizer;
|
|
sqlite3_tokenizer_cursor *pCursor;
|
|
const char *pToken;
|
|
int nTokenBytes;
|
|
int iStartOffset, iEndOffset, iPosition;
|
|
int rc;
|
|
|
|
rc = pTokenizer->pModule->xOpen(pTokenizer, zText, -1, &pCursor);
|
|
if( rc!=SQLITE_OK ) return rc;
|
|
|
|
pCursor->pTokenizer = pTokenizer;
|
|
while( SQLITE_OK==pTokenizer->pModule->xNext(pCursor,
|
|
&pToken, &nTokenBytes,
|
|
&iStartOffset, &iEndOffset,
|
|
&iPosition) ){
|
|
DocList *p;
|
|
|
|
/* Positions can't be negative; we use -1 as a terminator internally. */
|
|
if( iPosition<0 ){
|
|
pTokenizer->pModule->xClose(pCursor);
|
|
return SQLITE_ERROR;
|
|
}
|
|
|
|
p = fts1HashFind(terms, pToken, nTokenBytes);
|
|
if( p==NULL ){
|
|
p = docListNew(DL_DEFAULT);
|
|
docListAddDocid(p, iDocid);
|
|
fts1HashInsert(terms, pToken, nTokenBytes, p);
|
|
}
|
|
if( iColumn>=0 ){
|
|
docListAddPosOffset(p, iColumn, iPosition, iStartOffset, iEndOffset);
|
|
}
|
|
}
|
|
|
|
/* TODO(shess) Check return? Should this be able to cause errors at
|
|
** this point? Actually, same question about sqlite3_finalize(),
|
|
** though one could argue that failure there means that the data is
|
|
** not durable. *ponder*
|
|
*/
|
|
pTokenizer->pModule->xClose(pCursor);
|
|
return rc;
|
|
}
|
|
|
|
/* Update the %_terms table to map the term [pTerm] to the given rowid. */
|
|
static int index_insert_term(fulltext_vtab *v, const char *pTerm, int nTerm,
|
|
DocList *d){
|
|
sqlite_int64 iIndexRow;
|
|
DocList doclist;
|
|
int iSegment = 0, rc;
|
|
|
|
rc = term_select(v, pTerm, nTerm, iSegment, &iIndexRow, &doclist);
|
|
if( rc==SQLITE_DONE ){
|
|
docListInit(&doclist, DL_DEFAULT, 0, 0);
|
|
docListUpdate(&doclist, d);
|
|
/* TODO(shess) Consider length(doclist)>CHUNK_MAX? */
|
|
rc = term_insert(v, NULL, pTerm, nTerm, iSegment, &doclist);
|
|
goto err;
|
|
}
|
|
if( rc!=SQLITE_ROW ) return SQLITE_ERROR;
|
|
|
|
docListUpdate(&doclist, d);
|
|
if( doclist.nData<=CHUNK_MAX ){
|
|
rc = term_update(v, iIndexRow, &doclist);
|
|
goto err;
|
|
}
|
|
|
|
/* Doclist doesn't fit, delete what's there, and accumulate
|
|
** forward.
|
|
*/
|
|
rc = term_delete(v, iIndexRow);
|
|
if( rc!=SQLITE_OK ) goto err;
|
|
|
|
/* Try to insert the doclist into a higher segment bucket. On
|
|
** failure, accumulate existing doclist with the doclist from that
|
|
** bucket, and put results in the next bucket.
|
|
*/
|
|
iSegment++;
|
|
while( (rc=term_insert(v, &iIndexRow, pTerm, nTerm, iSegment,
|
|
&doclist))!=SQLITE_OK ){
|
|
sqlite_int64 iSegmentRow;
|
|
DocList old;
|
|
int rc2;
|
|
|
|
/* Retain old error in case the term_insert() error was really an
|
|
** error rather than a bounced insert.
|
|
*/
|
|
rc2 = term_select(v, pTerm, nTerm, iSegment, &iSegmentRow, &old);
|
|
if( rc2!=SQLITE_ROW ) goto err;
|
|
|
|
rc = term_delete(v, iSegmentRow);
|
|
if( rc!=SQLITE_OK ) goto err;
|
|
|
|
/* Reusing lowest-number deleted row keeps the index smaller. */
|
|
if( iSegmentRow<iIndexRow ) iIndexRow = iSegmentRow;
|
|
|
|
/* doclist contains the newer data, so accumulate it over old.
|
|
** Then steal accumulated data for doclist.
|
|
*/
|
|
docListAccumulate(&old, &doclist);
|
|
docListDestroy(&doclist);
|
|
doclist = old;
|
|
|
|
iSegment++;
|
|
}
|
|
|
|
err:
|
|
docListDestroy(&doclist);
|
|
return rc;
|
|
}
|
|
|
|
/* Add doclists for all terms in [pValues] to the hash table [terms]. */
|
|
static int insertTerms(fulltext_vtab *v, fts1Hash *terms, sqlite_int64 iRowid,
|
|
sqlite3_value **pValues){
|
|
int i;
|
|
for(i = 0; i < v->nColumn ; ++i){
|
|
char *zText = (char*)sqlite3_value_text(pValues[i]);
|
|
int rc = buildTerms(v, terms, iRowid, zText, i);
|
|
if( rc!=SQLITE_OK ) return rc;
|
|
}
|
|
return SQLITE_OK;
|
|
}
|
|
|
|
/* Add empty doclists for all terms in the given row's content to the hash
|
|
* table [pTerms]. */
|
|
static int deleteTerms(fulltext_vtab *v, fts1Hash *pTerms, sqlite_int64 iRowid){
|
|
const char **pValues;
|
|
int i;
|
|
|
|
int rc = content_select(v, iRowid, &pValues);
|
|
if( rc!=SQLITE_OK ) return rc;
|
|
|
|
for(i = 0 ; i < v->nColumn; ++i) {
|
|
rc = buildTerms(v, pTerms, iRowid, pValues[i], -1);
|
|
if( rc!=SQLITE_OK ) break;
|
|
}
|
|
|
|
freeStringArray(v->nColumn, pValues);
|
|
return SQLITE_OK;
|
|
}
|
|
|
|
/* Insert a row into the %_content table; set *piRowid to be the ID of the
|
|
* new row. Fill [pTerms] with new doclists for the %_term table. */
|
|
static int index_insert(fulltext_vtab *v, sqlite3_value *pRequestRowid,
|
|
sqlite3_value **pValues,
|
|
sqlite_int64 *piRowid, fts1Hash *pTerms){
|
|
int rc;
|
|
|
|
rc = content_insert(v, pRequestRowid, pValues); /* execute an SQL INSERT */
|
|
if( rc!=SQLITE_OK ) return rc;
|
|
*piRowid = sqlite3_last_insert_rowid(v->db);
|
|
return insertTerms(v, pTerms, *piRowid, pValues);
|
|
}
|
|
|
|
/* Delete a row from the %_content table; fill [pTerms] with empty doclists
|
|
* to be written to the %_term table. */
|
|
static int index_delete(fulltext_vtab *v, sqlite_int64 iRow, fts1Hash *pTerms){
|
|
int rc = deleteTerms(v, pTerms, iRow);
|
|
if( rc!=SQLITE_OK ) return rc;
|
|
return content_delete(v, iRow); /* execute an SQL DELETE */
|
|
}
|
|
|
|
/* Update a row in the %_content table; fill [pTerms] with new doclists for the
|
|
* %_term table. */
|
|
static int index_update(fulltext_vtab *v, sqlite_int64 iRow,
|
|
sqlite3_value **pValues, fts1Hash *pTerms){
|
|
/* Generate an empty doclist for each term that previously appeared in this
|
|
* row. */
|
|
int rc = deleteTerms(v, pTerms, iRow);
|
|
if( rc!=SQLITE_OK ) return rc;
|
|
|
|
rc = content_update(v, pValues, iRow); /* execute an SQL UPDATE */
|
|
if( rc!=SQLITE_OK ) return rc;
|
|
|
|
/* Now add positions for terms which appear in the updated row. */
|
|
return insertTerms(v, pTerms, iRow, pValues);
|
|
}
|
|
|
|
/* This function implements the xUpdate callback; it is the top-level entry
|
|
* point for inserting, deleting or updating a row in a full-text table. */
|
|
static int fulltextUpdate(sqlite3_vtab *pVtab, int nArg, sqlite3_value **ppArg,
|
|
sqlite_int64 *pRowid){
|
|
fulltext_vtab *v = (fulltext_vtab *) pVtab;
|
|
fts1Hash terms; /* maps term string -> PosList */
|
|
int rc;
|
|
fts1HashElem *e;
|
|
|
|
TRACE(("FTS1 Update %p\n", pVtab));
|
|
|
|
fts1HashInit(&terms, FTS1_HASH_STRING, 1);
|
|
|
|
if( nArg<2 ){
|
|
rc = index_delete(v, sqlite3_value_int64(ppArg[0]), &terms);
|
|
} else if( sqlite3_value_type(ppArg[0]) != SQLITE_NULL ){
|
|
/* An update:
|
|
* ppArg[0] = old rowid
|
|
* ppArg[1] = new rowid
|
|
* ppArg[2..2+v->nColumn-1] = values
|
|
* ppArg[2+v->nColumn] = value for magic column (we ignore this)
|
|
*/
|
|
sqlite_int64 rowid = sqlite3_value_int64(ppArg[0]);
|
|
if( sqlite3_value_type(ppArg[1]) != SQLITE_INTEGER ||
|
|
sqlite3_value_int64(ppArg[1]) != rowid ){
|
|
rc = SQLITE_ERROR; /* we don't allow changing the rowid */
|
|
} else {
|
|
assert( nArg==2+v->nColumn+1);
|
|
rc = index_update(v, rowid, &ppArg[2], &terms);
|
|
}
|
|
} else {
|
|
/* An insert:
|
|
* ppArg[1] = requested rowid
|
|
* ppArg[2..2+v->nColumn-1] = values
|
|
* ppArg[2+v->nColumn] = value for magic column (we ignore this)
|
|
*/
|
|
assert( nArg==2+v->nColumn+1);
|
|
rc = index_insert(v, ppArg[1], &ppArg[2], pRowid, &terms);
|
|
}
|
|
|
|
if( rc==SQLITE_OK ){
|
|
/* Write updated doclists to disk. */
|
|
for(e=fts1HashFirst(&terms); e; e=fts1HashNext(e)){
|
|
DocList *p = fts1HashData(e);
|
|
rc = index_insert_term(v, fts1HashKey(e), fts1HashKeysize(e), p);
|
|
if( rc!=SQLITE_OK ) break;
|
|
}
|
|
}
|
|
|
|
/* clean up */
|
|
for(e=fts1HashFirst(&terms); e; e=fts1HashNext(e)){
|
|
DocList *p = fts1HashData(e);
|
|
docListDelete(p);
|
|
}
|
|
fts1HashClear(&terms);
|
|
|
|
return rc;
|
|
}
|
|
|
|
/*
|
|
** Implementation of the snippet() function for FTS1
|
|
*/
|
|
static void snippetFunc(
|
|
sqlite3_context *pContext,
|
|
int argc,
|
|
sqlite3_value **argv
|
|
){
|
|
fulltext_cursor *pCursor;
|
|
if( argc<1 ) return;
|
|
if( sqlite3_value_type(argv[0])!=SQLITE_BLOB ||
|
|
sqlite3_value_bytes(argv[0])!=sizeof(pCursor) ){
|
|
sqlite3_result_error(pContext, "illegal first argument to html_snippet",-1);
|
|
}else{
|
|
const char *zStart = "<b>";
|
|
const char *zEnd = "</b>";
|
|
const char *zEllipsis = "<b>...</b>";
|
|
memcpy(&pCursor, sqlite3_value_blob(argv[0]), sizeof(pCursor));
|
|
if( argc>=2 ){
|
|
zStart = (const char*)sqlite3_value_text(argv[1]);
|
|
if( argc>=3 ){
|
|
zEnd = (const char*)sqlite3_value_text(argv[2]);
|
|
if( argc>=4 ){
|
|
zEllipsis = (const char*)sqlite3_value_text(argv[3]);
|
|
}
|
|
}
|
|
}
|
|
snippetAllOffsets(pCursor);
|
|
snippetText(pCursor, zStart, zEnd, zEllipsis);
|
|
sqlite3_result_text(pContext, pCursor->snippet.zSnippet,
|
|
pCursor->snippet.nSnippet, SQLITE_STATIC);
|
|
}
|
|
}
|
|
|
|
/*
|
|
** Implementation of the offsets() function for FTS1
|
|
*/
|
|
static void snippetOffsetsFunc(
|
|
sqlite3_context *pContext,
|
|
int argc,
|
|
sqlite3_value **argv
|
|
){
|
|
fulltext_cursor *pCursor;
|
|
if( argc<1 ) return;
|
|
if( sqlite3_value_type(argv[0])!=SQLITE_BLOB ||
|
|
sqlite3_value_bytes(argv[0])!=sizeof(pCursor) ){
|
|
sqlite3_result_error(pContext, "illegal first argument to offsets",-1);
|
|
}else{
|
|
memcpy(&pCursor, sqlite3_value_blob(argv[0]), sizeof(pCursor));
|
|
snippetAllOffsets(pCursor);
|
|
snippetOffsetText(&pCursor->snippet);
|
|
sqlite3_result_text(pContext,
|
|
pCursor->snippet.zOffset, pCursor->snippet.nOffset,
|
|
SQLITE_STATIC);
|
|
}
|
|
}
|
|
|
|
/*
|
|
** This routine implements the xFindFunction method for the FTS1
|
|
** virtual table.
|
|
*/
|
|
static int fulltextFindFunction(
|
|
sqlite3_vtab *pVtab,
|
|
int nArg,
|
|
const char *zName,
|
|
void (**pxFunc)(sqlite3_context*,int,sqlite3_value**),
|
|
void **ppArg
|
|
){
|
|
if( strcmp(zName,"snippet")==0 ){
|
|
*pxFunc = snippetFunc;
|
|
return 1;
|
|
}else if( strcmp(zName,"offsets")==0 ){
|
|
*pxFunc = snippetOffsetsFunc;
|
|
return 1;
|
|
}
|
|
return 0;
|
|
}
|
|
|
|
/*
|
|
** Rename an fts1 table.
|
|
*/
|
|
static int fulltextRename(
|
|
sqlite3_vtab *pVtab,
|
|
const char *zName
|
|
){
|
|
fulltext_vtab *p = (fulltext_vtab *)pVtab;
|
|
int rc = SQLITE_NOMEM;
|
|
char *zSql = sqlite3_mprintf(
|
|
"ALTER TABLE %Q.'%q_content' RENAME TO '%q_content';"
|
|
"ALTER TABLE %Q.'%q_term' RENAME TO '%q_term';"
|
|
, p->zDb, p->zName, zName
|
|
, p->zDb, p->zName, zName
|
|
);
|
|
if( zSql ){
|
|
rc = sqlite3_exec(p->db, zSql, 0, 0, 0);
|
|
sqlite3_free(zSql);
|
|
}
|
|
return rc;
|
|
}
|
|
|
|
static const sqlite3_module fulltextModule = {
|
|
/* iVersion */ 0,
|
|
/* xCreate */ fulltextCreate,
|
|
/* xConnect */ fulltextConnect,
|
|
/* xBestIndex */ fulltextBestIndex,
|
|
/* xDisconnect */ fulltextDisconnect,
|
|
/* xDestroy */ fulltextDestroy,
|
|
/* xOpen */ fulltextOpen,
|
|
/* xClose */ fulltextClose,
|
|
/* xFilter */ fulltextFilter,
|
|
/* xNext */ fulltextNext,
|
|
/* xEof */ fulltextEof,
|
|
/* xColumn */ fulltextColumn,
|
|
/* xRowid */ fulltextRowid,
|
|
/* xUpdate */ fulltextUpdate,
|
|
/* xBegin */ 0,
|
|
/* xSync */ 0,
|
|
/* xCommit */ 0,
|
|
/* xRollback */ 0,
|
|
/* xFindFunction */ fulltextFindFunction,
|
|
/* xRename */ fulltextRename,
|
|
};
|
|
|
|
int sqlite3Fts1Init(sqlite3 *db){
|
|
sqlite3_overload_function(db, "snippet", -1);
|
|
sqlite3_overload_function(db, "offsets", -1);
|
|
return sqlite3_create_module(db, "fts1", &fulltextModule, 0);
|
|
}
|
|
|
|
#if !SQLITE_CORE
|
|
#ifdef _WIN32
|
|
__declspec(dllexport)
|
|
#endif
|
|
int sqlite3_fts1_init(sqlite3 *db, char **pzErrMsg,
|
|
const sqlite3_api_routines *pApi){
|
|
SQLITE_EXTENSION_INIT2(pApi)
|
|
return sqlite3Fts1Init(db);
|
|
}
|
|
#endif
|
|
|
|
#endif /* !defined(SQLITE_CORE) || defined(SQLITE_ENABLE_FTS1) */
|