3367 lines
94 KiB
C
3367 lines
94 KiB
C
/*
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** 2001 September 15
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**
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** The author disclaims copyright to this source code. In place of
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** a legal notice, here is a blessing:
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**
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** May you do good and not evil.
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** May you find forgiveness for yourself and forgive others.
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** May you share freely, never taking more than you give.
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**
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*************************************************************************
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** This file contains code for implementations of the r-tree and r*-tree
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** algorithms packaged as an SQLite virtual table module.
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*/
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/*
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** Database Format of R-Tree Tables
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** --------------------------------
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**
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** The data structure for a single virtual r-tree table is stored in three
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** native SQLite tables declared as follows. In each case, the '%' character
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** in the table name is replaced with the user-supplied name of the r-tree
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** table.
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**
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** CREATE TABLE %_node(nodeno INTEGER PRIMARY KEY, data BLOB)
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** CREATE TABLE %_parent(nodeno INTEGER PRIMARY KEY, parentnode INTEGER)
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** CREATE TABLE %_rowid(rowid INTEGER PRIMARY KEY, nodeno INTEGER)
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**
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** The data for each node of the r-tree structure is stored in the %_node
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** table. For each node that is not the root node of the r-tree, there is
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** an entry in the %_parent table associating the node with its parent.
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** And for each row of data in the table, there is an entry in the %_rowid
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** table that maps from the entries rowid to the id of the node that it
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** is stored on.
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**
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** The root node of an r-tree always exists, even if the r-tree table is
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** empty. The nodeno of the root node is always 1. All other nodes in the
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** table must be the same size as the root node. The content of each node
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** is formatted as follows:
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**
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** 1. If the node is the root node (node 1), then the first 2 bytes
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** of the node contain the tree depth as a big-endian integer.
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** For non-root nodes, the first 2 bytes are left unused.
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**
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** 2. The next 2 bytes contain the number of entries currently
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** stored in the node.
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**
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** 3. The remainder of the node contains the node entries. Each entry
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** consists of a single 8-byte integer followed by an even number
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** of 4-byte coordinates. For leaf nodes the integer is the rowid
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** of a record. For internal nodes it is the node number of a
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** child page.
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*/
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#if !defined(SQLITE_CORE) || defined(SQLITE_ENABLE_RTREE)
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/*
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** This file contains an implementation of a couple of different variants
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** of the r-tree algorithm. See the README file for further details. The
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** same data-structure is used for all, but the algorithms for insert and
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** delete operations vary. The variants used are selected at compile time
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** by defining the following symbols:
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*/
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/* Either, both or none of the following may be set to activate
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** r*tree variant algorithms.
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*/
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#define VARIANT_RSTARTREE_CHOOSESUBTREE 0
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#define VARIANT_RSTARTREE_REINSERT 1
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/*
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** Exactly one of the following must be set to 1.
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*/
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#define VARIANT_GUTTMAN_QUADRATIC_SPLIT 0
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#define VARIANT_GUTTMAN_LINEAR_SPLIT 0
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#define VARIANT_RSTARTREE_SPLIT 1
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#define VARIANT_GUTTMAN_SPLIT \
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(VARIANT_GUTTMAN_LINEAR_SPLIT||VARIANT_GUTTMAN_QUADRATIC_SPLIT)
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#if VARIANT_GUTTMAN_QUADRATIC_SPLIT
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#define PickNext QuadraticPickNext
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#define PickSeeds QuadraticPickSeeds
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#define AssignCells splitNodeGuttman
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#endif
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#if VARIANT_GUTTMAN_LINEAR_SPLIT
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#define PickNext LinearPickNext
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#define PickSeeds LinearPickSeeds
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#define AssignCells splitNodeGuttman
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#endif
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#if VARIANT_RSTARTREE_SPLIT
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#define AssignCells splitNodeStartree
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#endif
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#if !defined(NDEBUG) && !defined(SQLITE_DEBUG)
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# define NDEBUG 1
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#endif
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#ifndef SQLITE_CORE
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#include "sqlite3ext.h"
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SQLITE_EXTENSION_INIT1
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#else
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#include "sqlite3.h"
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#endif
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#include <string.h>
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#include <assert.h>
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#ifndef SQLITE_AMALGAMATION
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#include "sqlite3rtree.h"
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typedef sqlite3_int64 i64;
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typedef unsigned char u8;
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typedef unsigned int u32;
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#endif
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/* The following macro is used to suppress compiler warnings.
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*/
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#ifndef UNUSED_PARAMETER
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# define UNUSED_PARAMETER(x) (void)(x)
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#endif
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typedef struct Rtree Rtree;
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typedef struct RtreeCursor RtreeCursor;
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typedef struct RtreeNode RtreeNode;
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typedef struct RtreeCell RtreeCell;
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typedef struct RtreeConstraint RtreeConstraint;
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typedef struct RtreeMatchArg RtreeMatchArg;
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typedef struct RtreeGeomCallback RtreeGeomCallback;
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typedef union RtreeCoord RtreeCoord;
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/* The rtree may have between 1 and RTREE_MAX_DIMENSIONS dimensions. */
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#define RTREE_MAX_DIMENSIONS 5
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/* Size of hash table Rtree.aHash. This hash table is not expected to
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** ever contain very many entries, so a fixed number of buckets is
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** used.
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*/
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#define HASHSIZE 128
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/*
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** An rtree virtual-table object.
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*/
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struct Rtree {
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sqlite3_vtab base;
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sqlite3 *db; /* Host database connection */
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int iNodeSize; /* Size in bytes of each node in the node table */
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int nDim; /* Number of dimensions */
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int nBytesPerCell; /* Bytes consumed per cell */
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int iDepth; /* Current depth of the r-tree structure */
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char *zDb; /* Name of database containing r-tree table */
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char *zName; /* Name of r-tree table */
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RtreeNode *aHash[HASHSIZE]; /* Hash table of in-memory nodes. */
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int nBusy; /* Current number of users of this structure */
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/* List of nodes removed during a CondenseTree operation. List is
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** linked together via the pointer normally used for hash chains -
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** RtreeNode.pNext. RtreeNode.iNode stores the depth of the sub-tree
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** headed by the node (leaf nodes have RtreeNode.iNode==0).
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*/
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RtreeNode *pDeleted;
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int iReinsertHeight; /* Height of sub-trees Reinsert() has run on */
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/* Statements to read/write/delete a record from xxx_node */
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sqlite3_stmt *pReadNode;
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sqlite3_stmt *pWriteNode;
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sqlite3_stmt *pDeleteNode;
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/* Statements to read/write/delete a record from xxx_rowid */
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sqlite3_stmt *pReadRowid;
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sqlite3_stmt *pWriteRowid;
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sqlite3_stmt *pDeleteRowid;
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/* Statements to read/write/delete a record from xxx_parent */
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sqlite3_stmt *pReadParent;
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sqlite3_stmt *pWriteParent;
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sqlite3_stmt *pDeleteParent;
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int eCoordType;
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};
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/* Possible values for eCoordType: */
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#define RTREE_COORD_REAL32 0
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#define RTREE_COORD_INT32 1
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/*
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** If SQLITE_RTREE_INT_ONLY is defined, then this virtual table will
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** only deal with integer coordinates. No floating point operations
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** will be done.
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*/
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#ifdef SQLITE_RTREE_INT_ONLY
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typedef sqlite3_int64 RtreeDValue; /* High accuracy coordinate */
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typedef int RtreeValue; /* Low accuracy coordinate */
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#else
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typedef double RtreeDValue; /* High accuracy coordinate */
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typedef float RtreeValue; /* Low accuracy coordinate */
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#endif
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/*
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** The minimum number of cells allowed for a node is a third of the
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** maximum. In Gutman's notation:
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**
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** m = M/3
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**
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** If an R*-tree "Reinsert" operation is required, the same number of
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** cells are removed from the overfull node and reinserted into the tree.
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*/
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#define RTREE_MINCELLS(p) ((((p)->iNodeSize-4)/(p)->nBytesPerCell)/3)
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#define RTREE_REINSERT(p) RTREE_MINCELLS(p)
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#define RTREE_MAXCELLS 51
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/*
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** The smallest possible node-size is (512-64)==448 bytes. And the largest
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** supported cell size is 48 bytes (8 byte rowid + ten 4 byte coordinates).
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** Therefore all non-root nodes must contain at least 3 entries. Since
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** 2^40 is greater than 2^64, an r-tree structure always has a depth of
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** 40 or less.
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*/
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#define RTREE_MAX_DEPTH 40
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/*
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** An rtree cursor object.
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*/
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struct RtreeCursor {
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sqlite3_vtab_cursor base;
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RtreeNode *pNode; /* Node cursor is currently pointing at */
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int iCell; /* Index of current cell in pNode */
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int iStrategy; /* Copy of idxNum search parameter */
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int nConstraint; /* Number of entries in aConstraint */
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RtreeConstraint *aConstraint; /* Search constraints. */
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};
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union RtreeCoord {
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RtreeValue f;
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int i;
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};
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/*
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** The argument is an RtreeCoord. Return the value stored within the RtreeCoord
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** formatted as a RtreeDValue (double or int64). This macro assumes that local
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** variable pRtree points to the Rtree structure associated with the
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** RtreeCoord.
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*/
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#ifdef SQLITE_RTREE_INT_ONLY
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# define DCOORD(coord) ((RtreeDValue)coord.i)
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#else
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# define DCOORD(coord) ( \
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(pRtree->eCoordType==RTREE_COORD_REAL32) ? \
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((double)coord.f) : \
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((double)coord.i) \
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)
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#endif
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/*
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** A search constraint.
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*/
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struct RtreeConstraint {
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int iCoord; /* Index of constrained coordinate */
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int op; /* Constraining operation */
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RtreeDValue rValue; /* Constraint value. */
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int (*xGeom)(sqlite3_rtree_geometry*, int, RtreeDValue*, int*);
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sqlite3_rtree_geometry *pGeom; /* Constraint callback argument for a MATCH */
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};
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/* Possible values for RtreeConstraint.op */
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#define RTREE_EQ 0x41
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#define RTREE_LE 0x42
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#define RTREE_LT 0x43
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#define RTREE_GE 0x44
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#define RTREE_GT 0x45
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#define RTREE_MATCH 0x46
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/*
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** An rtree structure node.
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*/
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struct RtreeNode {
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RtreeNode *pParent; /* Parent node */
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i64 iNode;
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int nRef;
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int isDirty;
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u8 *zData;
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RtreeNode *pNext; /* Next node in this hash chain */
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};
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#define NCELL(pNode) readInt16(&(pNode)->zData[2])
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/*
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** Structure to store a deserialized rtree record.
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*/
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struct RtreeCell {
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i64 iRowid;
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RtreeCoord aCoord[RTREE_MAX_DIMENSIONS*2];
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};
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/*
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** Value for the first field of every RtreeMatchArg object. The MATCH
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** operator tests that the first field of a blob operand matches this
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** value to avoid operating on invalid blobs (which could cause a segfault).
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*/
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#define RTREE_GEOMETRY_MAGIC 0x891245AB
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/*
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** An instance of this structure must be supplied as a blob argument to
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** the right-hand-side of an SQL MATCH operator used to constrain an
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** r-tree query.
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*/
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struct RtreeMatchArg {
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u32 magic; /* Always RTREE_GEOMETRY_MAGIC */
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int (*xGeom)(sqlite3_rtree_geometry *, int, RtreeDValue*, int *);
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void *pContext;
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int nParam;
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RtreeDValue aParam[1];
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};
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/*
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** When a geometry callback is created (see sqlite3_rtree_geometry_callback),
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** a single instance of the following structure is allocated. It is used
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** as the context for the user-function created by by s_r_g_c(). The object
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** is eventually deleted by the destructor mechanism provided by
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** sqlite3_create_function_v2() (which is called by s_r_g_c() to create
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** the geometry callback function).
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*/
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struct RtreeGeomCallback {
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int (*xGeom)(sqlite3_rtree_geometry*, int, RtreeDValue*, int*);
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void *pContext;
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};
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#ifndef MAX
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# define MAX(x,y) ((x) < (y) ? (y) : (x))
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#endif
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#ifndef MIN
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# define MIN(x,y) ((x) > (y) ? (y) : (x))
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#endif
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/*
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** Functions to deserialize a 16 bit integer, 32 bit real number and
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** 64 bit integer. The deserialized value is returned.
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*/
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static int readInt16(u8 *p){
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return (p[0]<<8) + p[1];
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}
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static void readCoord(u8 *p, RtreeCoord *pCoord){
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u32 i = (
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(((u32)p[0]) << 24) +
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(((u32)p[1]) << 16) +
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(((u32)p[2]) << 8) +
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(((u32)p[3]) << 0)
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);
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*(u32 *)pCoord = i;
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}
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static i64 readInt64(u8 *p){
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return (
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(((i64)p[0]) << 56) +
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(((i64)p[1]) << 48) +
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(((i64)p[2]) << 40) +
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(((i64)p[3]) << 32) +
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(((i64)p[4]) << 24) +
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(((i64)p[5]) << 16) +
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(((i64)p[6]) << 8) +
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(((i64)p[7]) << 0)
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);
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}
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/*
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** Functions to serialize a 16 bit integer, 32 bit real number and
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** 64 bit integer. The value returned is the number of bytes written
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** to the argument buffer (always 2, 4 and 8 respectively).
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*/
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static int writeInt16(u8 *p, int i){
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p[0] = (i>> 8)&0xFF;
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p[1] = (i>> 0)&0xFF;
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return 2;
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}
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static int writeCoord(u8 *p, RtreeCoord *pCoord){
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u32 i;
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assert( sizeof(RtreeCoord)==4 );
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assert( sizeof(u32)==4 );
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i = *(u32 *)pCoord;
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p[0] = (i>>24)&0xFF;
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p[1] = (i>>16)&0xFF;
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p[2] = (i>> 8)&0xFF;
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p[3] = (i>> 0)&0xFF;
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return 4;
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}
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static int writeInt64(u8 *p, i64 i){
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p[0] = (i>>56)&0xFF;
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p[1] = (i>>48)&0xFF;
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p[2] = (i>>40)&0xFF;
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p[3] = (i>>32)&0xFF;
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p[4] = (i>>24)&0xFF;
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p[5] = (i>>16)&0xFF;
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p[6] = (i>> 8)&0xFF;
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p[7] = (i>> 0)&0xFF;
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return 8;
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}
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/*
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** Increment the reference count of node p.
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*/
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static void nodeReference(RtreeNode *p){
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if( p ){
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p->nRef++;
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}
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}
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/*
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** Clear the content of node p (set all bytes to 0x00).
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*/
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static void nodeZero(Rtree *pRtree, RtreeNode *p){
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memset(&p->zData[2], 0, pRtree->iNodeSize-2);
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p->isDirty = 1;
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}
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/*
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** Given a node number iNode, return the corresponding key to use
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** in the Rtree.aHash table.
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*/
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static int nodeHash(i64 iNode){
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return (
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(iNode>>56) ^ (iNode>>48) ^ (iNode>>40) ^ (iNode>>32) ^
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(iNode>>24) ^ (iNode>>16) ^ (iNode>> 8) ^ (iNode>> 0)
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) % HASHSIZE;
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}
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/*
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** Search the node hash table for node iNode. If found, return a pointer
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** to it. Otherwise, return 0.
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*/
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static RtreeNode *nodeHashLookup(Rtree *pRtree, i64 iNode){
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RtreeNode *p;
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for(p=pRtree->aHash[nodeHash(iNode)]; p && p->iNode!=iNode; p=p->pNext);
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return p;
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}
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/*
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** Add node pNode to the node hash table.
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*/
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static void nodeHashInsert(Rtree *pRtree, RtreeNode *pNode){
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int iHash;
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assert( pNode->pNext==0 );
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iHash = nodeHash(pNode->iNode);
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pNode->pNext = pRtree->aHash[iHash];
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pRtree->aHash[iHash] = pNode;
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}
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/*
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** Remove node pNode from the node hash table.
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*/
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static void nodeHashDelete(Rtree *pRtree, RtreeNode *pNode){
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RtreeNode **pp;
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if( pNode->iNode!=0 ){
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pp = &pRtree->aHash[nodeHash(pNode->iNode)];
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for( ; (*pp)!=pNode; pp = &(*pp)->pNext){ assert(*pp); }
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*pp = pNode->pNext;
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pNode->pNext = 0;
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}
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}
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/*
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** Allocate and return new r-tree node. Initially, (RtreeNode.iNode==0),
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** indicating that node has not yet been assigned a node number. It is
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** assigned a node number when nodeWrite() is called to write the
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** node contents out to the database.
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*/
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static RtreeNode *nodeNew(Rtree *pRtree, RtreeNode *pParent){
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RtreeNode *pNode;
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pNode = (RtreeNode *)sqlite3_malloc(sizeof(RtreeNode) + pRtree->iNodeSize);
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if( pNode ){
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memset(pNode, 0, sizeof(RtreeNode) + pRtree->iNodeSize);
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pNode->zData = (u8 *)&pNode[1];
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pNode->nRef = 1;
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pNode->pParent = pParent;
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pNode->isDirty = 1;
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nodeReference(pParent);
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}
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return pNode;
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}
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/*
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** Obtain a reference to an r-tree node.
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*/
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static int
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nodeAcquire(
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Rtree *pRtree, /* R-tree structure */
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i64 iNode, /* Node number to load */
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RtreeNode *pParent, /* Either the parent node or NULL */
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RtreeNode **ppNode /* OUT: Acquired node */
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){
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int rc;
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int rc2 = SQLITE_OK;
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RtreeNode *pNode;
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/* Check if the requested node is already in the hash table. If so,
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** increase its reference count and return it.
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*/
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if( (pNode = nodeHashLookup(pRtree, iNode)) ){
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assert( !pParent || !pNode->pParent || pNode->pParent==pParent );
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if( pParent && !pNode->pParent ){
|
|
nodeReference(pParent);
|
|
pNode->pParent = pParent;
|
|
}
|
|
pNode->nRef++;
|
|
*ppNode = pNode;
|
|
return SQLITE_OK;
|
|
}
|
|
|
|
sqlite3_bind_int64(pRtree->pReadNode, 1, iNode);
|
|
rc = sqlite3_step(pRtree->pReadNode);
|
|
if( rc==SQLITE_ROW ){
|
|
const u8 *zBlob = sqlite3_column_blob(pRtree->pReadNode, 0);
|
|
if( pRtree->iNodeSize==sqlite3_column_bytes(pRtree->pReadNode, 0) ){
|
|
pNode = (RtreeNode *)sqlite3_malloc(sizeof(RtreeNode)+pRtree->iNodeSize);
|
|
if( !pNode ){
|
|
rc2 = SQLITE_NOMEM;
|
|
}else{
|
|
pNode->pParent = pParent;
|
|
pNode->zData = (u8 *)&pNode[1];
|
|
pNode->nRef = 1;
|
|
pNode->iNode = iNode;
|
|
pNode->isDirty = 0;
|
|
pNode->pNext = 0;
|
|
memcpy(pNode->zData, zBlob, pRtree->iNodeSize);
|
|
nodeReference(pParent);
|
|
}
|
|
}
|
|
}
|
|
rc = sqlite3_reset(pRtree->pReadNode);
|
|
if( rc==SQLITE_OK ) rc = rc2;
|
|
|
|
/* If the root node was just loaded, set pRtree->iDepth to the height
|
|
** of the r-tree structure. A height of zero means all data is stored on
|
|
** the root node. A height of one means the children of the root node
|
|
** are the leaves, and so on. If the depth as specified on the root node
|
|
** is greater than RTREE_MAX_DEPTH, the r-tree structure must be corrupt.
|
|
*/
|
|
if( pNode && iNode==1 ){
|
|
pRtree->iDepth = readInt16(pNode->zData);
|
|
if( pRtree->iDepth>RTREE_MAX_DEPTH ){
|
|
rc = SQLITE_CORRUPT_VTAB;
|
|
}
|
|
}
|
|
|
|
/* If no error has occurred so far, check if the "number of entries"
|
|
** field on the node is too large. If so, set the return code to
|
|
** SQLITE_CORRUPT_VTAB.
|
|
*/
|
|
if( pNode && rc==SQLITE_OK ){
|
|
if( NCELL(pNode)>((pRtree->iNodeSize-4)/pRtree->nBytesPerCell) ){
|
|
rc = SQLITE_CORRUPT_VTAB;
|
|
}
|
|
}
|
|
|
|
if( rc==SQLITE_OK ){
|
|
if( pNode!=0 ){
|
|
nodeHashInsert(pRtree, pNode);
|
|
}else{
|
|
rc = SQLITE_CORRUPT_VTAB;
|
|
}
|
|
*ppNode = pNode;
|
|
}else{
|
|
sqlite3_free(pNode);
|
|
*ppNode = 0;
|
|
}
|
|
|
|
return rc;
|
|
}
|
|
|
|
/*
|
|
** Overwrite cell iCell of node pNode with the contents of pCell.
|
|
*/
|
|
static void nodeOverwriteCell(
|
|
Rtree *pRtree,
|
|
RtreeNode *pNode,
|
|
RtreeCell *pCell,
|
|
int iCell
|
|
){
|
|
int ii;
|
|
u8 *p = &pNode->zData[4 + pRtree->nBytesPerCell*iCell];
|
|
p += writeInt64(p, pCell->iRowid);
|
|
for(ii=0; ii<(pRtree->nDim*2); ii++){
|
|
p += writeCoord(p, &pCell->aCoord[ii]);
|
|
}
|
|
pNode->isDirty = 1;
|
|
}
|
|
|
|
/*
|
|
** Remove cell the cell with index iCell from node pNode.
|
|
*/
|
|
static void nodeDeleteCell(Rtree *pRtree, RtreeNode *pNode, int iCell){
|
|
u8 *pDst = &pNode->zData[4 + pRtree->nBytesPerCell*iCell];
|
|
u8 *pSrc = &pDst[pRtree->nBytesPerCell];
|
|
int nByte = (NCELL(pNode) - iCell - 1) * pRtree->nBytesPerCell;
|
|
memmove(pDst, pSrc, nByte);
|
|
writeInt16(&pNode->zData[2], NCELL(pNode)-1);
|
|
pNode->isDirty = 1;
|
|
}
|
|
|
|
/*
|
|
** Insert the contents of cell pCell into node pNode. If the insert
|
|
** is successful, return SQLITE_OK.
|
|
**
|
|
** If there is not enough free space in pNode, return SQLITE_FULL.
|
|
*/
|
|
static int
|
|
nodeInsertCell(
|
|
Rtree *pRtree,
|
|
RtreeNode *pNode,
|
|
RtreeCell *pCell
|
|
){
|
|
int nCell; /* Current number of cells in pNode */
|
|
int nMaxCell; /* Maximum number of cells for pNode */
|
|
|
|
nMaxCell = (pRtree->iNodeSize-4)/pRtree->nBytesPerCell;
|
|
nCell = NCELL(pNode);
|
|
|
|
assert( nCell<=nMaxCell );
|
|
if( nCell<nMaxCell ){
|
|
nodeOverwriteCell(pRtree, pNode, pCell, nCell);
|
|
writeInt16(&pNode->zData[2], nCell+1);
|
|
pNode->isDirty = 1;
|
|
}
|
|
|
|
return (nCell==nMaxCell);
|
|
}
|
|
|
|
/*
|
|
** If the node is dirty, write it out to the database.
|
|
*/
|
|
static int
|
|
nodeWrite(Rtree *pRtree, RtreeNode *pNode){
|
|
int rc = SQLITE_OK;
|
|
if( pNode->isDirty ){
|
|
sqlite3_stmt *p = pRtree->pWriteNode;
|
|
if( pNode->iNode ){
|
|
sqlite3_bind_int64(p, 1, pNode->iNode);
|
|
}else{
|
|
sqlite3_bind_null(p, 1);
|
|
}
|
|
sqlite3_bind_blob(p, 2, pNode->zData, pRtree->iNodeSize, SQLITE_STATIC);
|
|
sqlite3_step(p);
|
|
pNode->isDirty = 0;
|
|
rc = sqlite3_reset(p);
|
|
if( pNode->iNode==0 && rc==SQLITE_OK ){
|
|
pNode->iNode = sqlite3_last_insert_rowid(pRtree->db);
|
|
nodeHashInsert(pRtree, pNode);
|
|
}
|
|
}
|
|
return rc;
|
|
}
|
|
|
|
/*
|
|
** Release a reference to a node. If the node is dirty and the reference
|
|
** count drops to zero, the node data is written to the database.
|
|
*/
|
|
static int
|
|
nodeRelease(Rtree *pRtree, RtreeNode *pNode){
|
|
int rc = SQLITE_OK;
|
|
if( pNode ){
|
|
assert( pNode->nRef>0 );
|
|
pNode->nRef--;
|
|
if( pNode->nRef==0 ){
|
|
if( pNode->iNode==1 ){
|
|
pRtree->iDepth = -1;
|
|
}
|
|
if( pNode->pParent ){
|
|
rc = nodeRelease(pRtree, pNode->pParent);
|
|
}
|
|
if( rc==SQLITE_OK ){
|
|
rc = nodeWrite(pRtree, pNode);
|
|
}
|
|
nodeHashDelete(pRtree, pNode);
|
|
sqlite3_free(pNode);
|
|
}
|
|
}
|
|
return rc;
|
|
}
|
|
|
|
/*
|
|
** Return the 64-bit integer value associated with cell iCell of
|
|
** node pNode. If pNode is a leaf node, this is a rowid. If it is
|
|
** an internal node, then the 64-bit integer is a child page number.
|
|
*/
|
|
static i64 nodeGetRowid(
|
|
Rtree *pRtree,
|
|
RtreeNode *pNode,
|
|
int iCell
|
|
){
|
|
assert( iCell<NCELL(pNode) );
|
|
return readInt64(&pNode->zData[4 + pRtree->nBytesPerCell*iCell]);
|
|
}
|
|
|
|
/*
|
|
** Return coordinate iCoord from cell iCell in node pNode.
|
|
*/
|
|
static void nodeGetCoord(
|
|
Rtree *pRtree,
|
|
RtreeNode *pNode,
|
|
int iCell,
|
|
int iCoord,
|
|
RtreeCoord *pCoord /* Space to write result to */
|
|
){
|
|
readCoord(&pNode->zData[12 + pRtree->nBytesPerCell*iCell + 4*iCoord], pCoord);
|
|
}
|
|
|
|
/*
|
|
** Deserialize cell iCell of node pNode. Populate the structure pointed
|
|
** to by pCell with the results.
|
|
*/
|
|
static void nodeGetCell(
|
|
Rtree *pRtree,
|
|
RtreeNode *pNode,
|
|
int iCell,
|
|
RtreeCell *pCell
|
|
){
|
|
int ii;
|
|
pCell->iRowid = nodeGetRowid(pRtree, pNode, iCell);
|
|
for(ii=0; ii<pRtree->nDim*2; ii++){
|
|
nodeGetCoord(pRtree, pNode, iCell, ii, &pCell->aCoord[ii]);
|
|
}
|
|
}
|
|
|
|
|
|
/* Forward declaration for the function that does the work of
|
|
** the virtual table module xCreate() and xConnect() methods.
|
|
*/
|
|
static int rtreeInit(
|
|
sqlite3 *, void *, int, const char *const*, sqlite3_vtab **, char **, int
|
|
);
|
|
|
|
/*
|
|
** Rtree virtual table module xCreate method.
|
|
*/
|
|
static int rtreeCreate(
|
|
sqlite3 *db,
|
|
void *pAux,
|
|
int argc, const char *const*argv,
|
|
sqlite3_vtab **ppVtab,
|
|
char **pzErr
|
|
){
|
|
return rtreeInit(db, pAux, argc, argv, ppVtab, pzErr, 1);
|
|
}
|
|
|
|
/*
|
|
** Rtree virtual table module xConnect method.
|
|
*/
|
|
static int rtreeConnect(
|
|
sqlite3 *db,
|
|
void *pAux,
|
|
int argc, const char *const*argv,
|
|
sqlite3_vtab **ppVtab,
|
|
char **pzErr
|
|
){
|
|
return rtreeInit(db, pAux, argc, argv, ppVtab, pzErr, 0);
|
|
}
|
|
|
|
/*
|
|
** Increment the r-tree reference count.
|
|
*/
|
|
static void rtreeReference(Rtree *pRtree){
|
|
pRtree->nBusy++;
|
|
}
|
|
|
|
/*
|
|
** Decrement the r-tree reference count. When the reference count reaches
|
|
** zero the structure is deleted.
|
|
*/
|
|
static void rtreeRelease(Rtree *pRtree){
|
|
pRtree->nBusy--;
|
|
if( pRtree->nBusy==0 ){
|
|
sqlite3_finalize(pRtree->pReadNode);
|
|
sqlite3_finalize(pRtree->pWriteNode);
|
|
sqlite3_finalize(pRtree->pDeleteNode);
|
|
sqlite3_finalize(pRtree->pReadRowid);
|
|
sqlite3_finalize(pRtree->pWriteRowid);
|
|
sqlite3_finalize(pRtree->pDeleteRowid);
|
|
sqlite3_finalize(pRtree->pReadParent);
|
|
sqlite3_finalize(pRtree->pWriteParent);
|
|
sqlite3_finalize(pRtree->pDeleteParent);
|
|
sqlite3_free(pRtree);
|
|
}
|
|
}
|
|
|
|
/*
|
|
** Rtree virtual table module xDisconnect method.
|
|
*/
|
|
static int rtreeDisconnect(sqlite3_vtab *pVtab){
|
|
rtreeRelease((Rtree *)pVtab);
|
|
return SQLITE_OK;
|
|
}
|
|
|
|
/*
|
|
** Rtree virtual table module xDestroy method.
|
|
*/
|
|
static int rtreeDestroy(sqlite3_vtab *pVtab){
|
|
Rtree *pRtree = (Rtree *)pVtab;
|
|
int rc;
|
|
char *zCreate = sqlite3_mprintf(
|
|
"DROP TABLE '%q'.'%q_node';"
|
|
"DROP TABLE '%q'.'%q_rowid';"
|
|
"DROP TABLE '%q'.'%q_parent';",
|
|
pRtree->zDb, pRtree->zName,
|
|
pRtree->zDb, pRtree->zName,
|
|
pRtree->zDb, pRtree->zName
|
|
);
|
|
if( !zCreate ){
|
|
rc = SQLITE_NOMEM;
|
|
}else{
|
|
rc = sqlite3_exec(pRtree->db, zCreate, 0, 0, 0);
|
|
sqlite3_free(zCreate);
|
|
}
|
|
if( rc==SQLITE_OK ){
|
|
rtreeRelease(pRtree);
|
|
}
|
|
|
|
return rc;
|
|
}
|
|
|
|
/*
|
|
** Rtree virtual table module xOpen method.
|
|
*/
|
|
static int rtreeOpen(sqlite3_vtab *pVTab, sqlite3_vtab_cursor **ppCursor){
|
|
int rc = SQLITE_NOMEM;
|
|
RtreeCursor *pCsr;
|
|
|
|
pCsr = (RtreeCursor *)sqlite3_malloc(sizeof(RtreeCursor));
|
|
if( pCsr ){
|
|
memset(pCsr, 0, sizeof(RtreeCursor));
|
|
pCsr->base.pVtab = pVTab;
|
|
rc = SQLITE_OK;
|
|
}
|
|
*ppCursor = (sqlite3_vtab_cursor *)pCsr;
|
|
|
|
return rc;
|
|
}
|
|
|
|
|
|
/*
|
|
** Free the RtreeCursor.aConstraint[] array and its contents.
|
|
*/
|
|
static void freeCursorConstraints(RtreeCursor *pCsr){
|
|
if( pCsr->aConstraint ){
|
|
int i; /* Used to iterate through constraint array */
|
|
for(i=0; i<pCsr->nConstraint; i++){
|
|
sqlite3_rtree_geometry *pGeom = pCsr->aConstraint[i].pGeom;
|
|
if( pGeom ){
|
|
if( pGeom->xDelUser ) pGeom->xDelUser(pGeom->pUser);
|
|
sqlite3_free(pGeom);
|
|
}
|
|
}
|
|
sqlite3_free(pCsr->aConstraint);
|
|
pCsr->aConstraint = 0;
|
|
}
|
|
}
|
|
|
|
/*
|
|
** Rtree virtual table module xClose method.
|
|
*/
|
|
static int rtreeClose(sqlite3_vtab_cursor *cur){
|
|
Rtree *pRtree = (Rtree *)(cur->pVtab);
|
|
int rc;
|
|
RtreeCursor *pCsr = (RtreeCursor *)cur;
|
|
freeCursorConstraints(pCsr);
|
|
rc = nodeRelease(pRtree, pCsr->pNode);
|
|
sqlite3_free(pCsr);
|
|
return rc;
|
|
}
|
|
|
|
/*
|
|
** Rtree virtual table module xEof method.
|
|
**
|
|
** Return non-zero if the cursor does not currently point to a valid
|
|
** record (i.e if the scan has finished), or zero otherwise.
|
|
*/
|
|
static int rtreeEof(sqlite3_vtab_cursor *cur){
|
|
RtreeCursor *pCsr = (RtreeCursor *)cur;
|
|
return (pCsr->pNode==0);
|
|
}
|
|
|
|
/*
|
|
** The r-tree constraint passed as the second argument to this function is
|
|
** guaranteed to be a MATCH constraint.
|
|
*/
|
|
static int testRtreeGeom(
|
|
Rtree *pRtree, /* R-Tree object */
|
|
RtreeConstraint *pConstraint, /* MATCH constraint to test */
|
|
RtreeCell *pCell, /* Cell to test */
|
|
int *pbRes /* OUT: Test result */
|
|
){
|
|
int i;
|
|
RtreeDValue aCoord[RTREE_MAX_DIMENSIONS*2];
|
|
int nCoord = pRtree->nDim*2;
|
|
|
|
assert( pConstraint->op==RTREE_MATCH );
|
|
assert( pConstraint->pGeom );
|
|
|
|
for(i=0; i<nCoord; i++){
|
|
aCoord[i] = DCOORD(pCell->aCoord[i]);
|
|
}
|
|
return pConstraint->xGeom(pConstraint->pGeom, nCoord, aCoord, pbRes);
|
|
}
|
|
|
|
/*
|
|
** Cursor pCursor currently points to a cell in a non-leaf page.
|
|
** Set *pbEof to true if the sub-tree headed by the cell is filtered
|
|
** (excluded) by the constraints in the pCursor->aConstraint[]
|
|
** array, or false otherwise.
|
|
**
|
|
** Return SQLITE_OK if successful or an SQLite error code if an error
|
|
** occurs within a geometry callback.
|
|
*/
|
|
static int testRtreeCell(Rtree *pRtree, RtreeCursor *pCursor, int *pbEof){
|
|
RtreeCell cell;
|
|
int ii;
|
|
int bRes = 0;
|
|
int rc = SQLITE_OK;
|
|
|
|
nodeGetCell(pRtree, pCursor->pNode, pCursor->iCell, &cell);
|
|
for(ii=0; bRes==0 && ii<pCursor->nConstraint; ii++){
|
|
RtreeConstraint *p = &pCursor->aConstraint[ii];
|
|
RtreeDValue cell_min = DCOORD(cell.aCoord[(p->iCoord>>1)*2]);
|
|
RtreeDValue cell_max = DCOORD(cell.aCoord[(p->iCoord>>1)*2+1]);
|
|
|
|
assert(p->op==RTREE_LE || p->op==RTREE_LT || p->op==RTREE_GE
|
|
|| p->op==RTREE_GT || p->op==RTREE_EQ || p->op==RTREE_MATCH
|
|
);
|
|
|
|
switch( p->op ){
|
|
case RTREE_LE: case RTREE_LT:
|
|
bRes = p->rValue<cell_min;
|
|
break;
|
|
|
|
case RTREE_GE: case RTREE_GT:
|
|
bRes = p->rValue>cell_max;
|
|
break;
|
|
|
|
case RTREE_EQ:
|
|
bRes = (p->rValue>cell_max || p->rValue<cell_min);
|
|
break;
|
|
|
|
default: {
|
|
assert( p->op==RTREE_MATCH );
|
|
rc = testRtreeGeom(pRtree, p, &cell, &bRes);
|
|
bRes = !bRes;
|
|
break;
|
|
}
|
|
}
|
|
}
|
|
|
|
*pbEof = bRes;
|
|
return rc;
|
|
}
|
|
|
|
/*
|
|
** Test if the cell that cursor pCursor currently points to
|
|
** would be filtered (excluded) by the constraints in the
|
|
** pCursor->aConstraint[] array. If so, set *pbEof to true before
|
|
** returning. If the cell is not filtered (excluded) by the constraints,
|
|
** set pbEof to zero.
|
|
**
|
|
** Return SQLITE_OK if successful or an SQLite error code if an error
|
|
** occurs within a geometry callback.
|
|
**
|
|
** This function assumes that the cell is part of a leaf node.
|
|
*/
|
|
static int testRtreeEntry(Rtree *pRtree, RtreeCursor *pCursor, int *pbEof){
|
|
RtreeCell cell;
|
|
int ii;
|
|
*pbEof = 0;
|
|
|
|
nodeGetCell(pRtree, pCursor->pNode, pCursor->iCell, &cell);
|
|
for(ii=0; ii<pCursor->nConstraint; ii++){
|
|
RtreeConstraint *p = &pCursor->aConstraint[ii];
|
|
RtreeDValue coord = DCOORD(cell.aCoord[p->iCoord]);
|
|
int res;
|
|
assert(p->op==RTREE_LE || p->op==RTREE_LT || p->op==RTREE_GE
|
|
|| p->op==RTREE_GT || p->op==RTREE_EQ || p->op==RTREE_MATCH
|
|
);
|
|
switch( p->op ){
|
|
case RTREE_LE: res = (coord<=p->rValue); break;
|
|
case RTREE_LT: res = (coord<p->rValue); break;
|
|
case RTREE_GE: res = (coord>=p->rValue); break;
|
|
case RTREE_GT: res = (coord>p->rValue); break;
|
|
case RTREE_EQ: res = (coord==p->rValue); break;
|
|
default: {
|
|
int rc;
|
|
assert( p->op==RTREE_MATCH );
|
|
rc = testRtreeGeom(pRtree, p, &cell, &res);
|
|
if( rc!=SQLITE_OK ){
|
|
return rc;
|
|
}
|
|
break;
|
|
}
|
|
}
|
|
|
|
if( !res ){
|
|
*pbEof = 1;
|
|
return SQLITE_OK;
|
|
}
|
|
}
|
|
|
|
return SQLITE_OK;
|
|
}
|
|
|
|
/*
|
|
** Cursor pCursor currently points at a node that heads a sub-tree of
|
|
** height iHeight (if iHeight==0, then the node is a leaf). Descend
|
|
** to point to the left-most cell of the sub-tree that matches the
|
|
** configured constraints.
|
|
*/
|
|
static int descendToCell(
|
|
Rtree *pRtree,
|
|
RtreeCursor *pCursor,
|
|
int iHeight,
|
|
int *pEof /* OUT: Set to true if cannot descend */
|
|
){
|
|
int isEof;
|
|
int rc;
|
|
int ii;
|
|
RtreeNode *pChild;
|
|
sqlite3_int64 iRowid;
|
|
|
|
RtreeNode *pSavedNode = pCursor->pNode;
|
|
int iSavedCell = pCursor->iCell;
|
|
|
|
assert( iHeight>=0 );
|
|
|
|
if( iHeight==0 ){
|
|
rc = testRtreeEntry(pRtree, pCursor, &isEof);
|
|
}else{
|
|
rc = testRtreeCell(pRtree, pCursor, &isEof);
|
|
}
|
|
if( rc!=SQLITE_OK || isEof || iHeight==0 ){
|
|
goto descend_to_cell_out;
|
|
}
|
|
|
|
iRowid = nodeGetRowid(pRtree, pCursor->pNode, pCursor->iCell);
|
|
rc = nodeAcquire(pRtree, iRowid, pCursor->pNode, &pChild);
|
|
if( rc!=SQLITE_OK ){
|
|
goto descend_to_cell_out;
|
|
}
|
|
|
|
nodeRelease(pRtree, pCursor->pNode);
|
|
pCursor->pNode = pChild;
|
|
isEof = 1;
|
|
for(ii=0; isEof && ii<NCELL(pChild); ii++){
|
|
pCursor->iCell = ii;
|
|
rc = descendToCell(pRtree, pCursor, iHeight-1, &isEof);
|
|
if( rc!=SQLITE_OK ){
|
|
goto descend_to_cell_out;
|
|
}
|
|
}
|
|
|
|
if( isEof ){
|
|
assert( pCursor->pNode==pChild );
|
|
nodeReference(pSavedNode);
|
|
nodeRelease(pRtree, pChild);
|
|
pCursor->pNode = pSavedNode;
|
|
pCursor->iCell = iSavedCell;
|
|
}
|
|
|
|
descend_to_cell_out:
|
|
*pEof = isEof;
|
|
return rc;
|
|
}
|
|
|
|
/*
|
|
** One of the cells in node pNode is guaranteed to have a 64-bit
|
|
** integer value equal to iRowid. Return the index of this cell.
|
|
*/
|
|
static int nodeRowidIndex(
|
|
Rtree *pRtree,
|
|
RtreeNode *pNode,
|
|
i64 iRowid,
|
|
int *piIndex
|
|
){
|
|
int ii;
|
|
int nCell = NCELL(pNode);
|
|
for(ii=0; ii<nCell; ii++){
|
|
if( nodeGetRowid(pRtree, pNode, ii)==iRowid ){
|
|
*piIndex = ii;
|
|
return SQLITE_OK;
|
|
}
|
|
}
|
|
return SQLITE_CORRUPT_VTAB;
|
|
}
|
|
|
|
/*
|
|
** Return the index of the cell containing a pointer to node pNode
|
|
** in its parent. If pNode is the root node, return -1.
|
|
*/
|
|
static int nodeParentIndex(Rtree *pRtree, RtreeNode *pNode, int *piIndex){
|
|
RtreeNode *pParent = pNode->pParent;
|
|
if( pParent ){
|
|
return nodeRowidIndex(pRtree, pParent, pNode->iNode, piIndex);
|
|
}
|
|
*piIndex = -1;
|
|
return SQLITE_OK;
|
|
}
|
|
|
|
/*
|
|
** Rtree virtual table module xNext method.
|
|
*/
|
|
static int rtreeNext(sqlite3_vtab_cursor *pVtabCursor){
|
|
Rtree *pRtree = (Rtree *)(pVtabCursor->pVtab);
|
|
RtreeCursor *pCsr = (RtreeCursor *)pVtabCursor;
|
|
int rc = SQLITE_OK;
|
|
|
|
/* RtreeCursor.pNode must not be NULL. If is is NULL, then this cursor is
|
|
** already at EOF. It is against the rules to call the xNext() method of
|
|
** a cursor that has already reached EOF.
|
|
*/
|
|
assert( pCsr->pNode );
|
|
|
|
if( pCsr->iStrategy==1 ){
|
|
/* This "scan" is a direct lookup by rowid. There is no next entry. */
|
|
nodeRelease(pRtree, pCsr->pNode);
|
|
pCsr->pNode = 0;
|
|
}else{
|
|
/* Move to the next entry that matches the configured constraints. */
|
|
int iHeight = 0;
|
|
while( pCsr->pNode ){
|
|
RtreeNode *pNode = pCsr->pNode;
|
|
int nCell = NCELL(pNode);
|
|
for(pCsr->iCell++; pCsr->iCell<nCell; pCsr->iCell++){
|
|
int isEof;
|
|
rc = descendToCell(pRtree, pCsr, iHeight, &isEof);
|
|
if( rc!=SQLITE_OK || !isEof ){
|
|
return rc;
|
|
}
|
|
}
|
|
pCsr->pNode = pNode->pParent;
|
|
rc = nodeParentIndex(pRtree, pNode, &pCsr->iCell);
|
|
if( rc!=SQLITE_OK ){
|
|
return rc;
|
|
}
|
|
nodeReference(pCsr->pNode);
|
|
nodeRelease(pRtree, pNode);
|
|
iHeight++;
|
|
}
|
|
}
|
|
|
|
return rc;
|
|
}
|
|
|
|
/*
|
|
** Rtree virtual table module xRowid method.
|
|
*/
|
|
static int rtreeRowid(sqlite3_vtab_cursor *pVtabCursor, sqlite_int64 *pRowid){
|
|
Rtree *pRtree = (Rtree *)pVtabCursor->pVtab;
|
|
RtreeCursor *pCsr = (RtreeCursor *)pVtabCursor;
|
|
|
|
assert(pCsr->pNode);
|
|
*pRowid = nodeGetRowid(pRtree, pCsr->pNode, pCsr->iCell);
|
|
|
|
return SQLITE_OK;
|
|
}
|
|
|
|
/*
|
|
** Rtree virtual table module xColumn method.
|
|
*/
|
|
static int rtreeColumn(sqlite3_vtab_cursor *cur, sqlite3_context *ctx, int i){
|
|
Rtree *pRtree = (Rtree *)cur->pVtab;
|
|
RtreeCursor *pCsr = (RtreeCursor *)cur;
|
|
|
|
if( i==0 ){
|
|
i64 iRowid = nodeGetRowid(pRtree, pCsr->pNode, pCsr->iCell);
|
|
sqlite3_result_int64(ctx, iRowid);
|
|
}else{
|
|
RtreeCoord c;
|
|
nodeGetCoord(pRtree, pCsr->pNode, pCsr->iCell, i-1, &c);
|
|
#ifndef SQLITE_RTREE_INT_ONLY
|
|
if( pRtree->eCoordType==RTREE_COORD_REAL32 ){
|
|
sqlite3_result_double(ctx, c.f);
|
|
}else
|
|
#endif
|
|
{
|
|
assert( pRtree->eCoordType==RTREE_COORD_INT32 );
|
|
sqlite3_result_int(ctx, c.i);
|
|
}
|
|
}
|
|
|
|
return SQLITE_OK;
|
|
}
|
|
|
|
/*
|
|
** Use nodeAcquire() to obtain the leaf node containing the record with
|
|
** rowid iRowid. If successful, set *ppLeaf to point to the node and
|
|
** return SQLITE_OK. If there is no such record in the table, set
|
|
** *ppLeaf to 0 and return SQLITE_OK. If an error occurs, set *ppLeaf
|
|
** to zero and return an SQLite error code.
|
|
*/
|
|
static int findLeafNode(Rtree *pRtree, i64 iRowid, RtreeNode **ppLeaf){
|
|
int rc;
|
|
*ppLeaf = 0;
|
|
sqlite3_bind_int64(pRtree->pReadRowid, 1, iRowid);
|
|
if( sqlite3_step(pRtree->pReadRowid)==SQLITE_ROW ){
|
|
i64 iNode = sqlite3_column_int64(pRtree->pReadRowid, 0);
|
|
rc = nodeAcquire(pRtree, iNode, 0, ppLeaf);
|
|
sqlite3_reset(pRtree->pReadRowid);
|
|
}else{
|
|
rc = sqlite3_reset(pRtree->pReadRowid);
|
|
}
|
|
return rc;
|
|
}
|
|
|
|
/*
|
|
** This function is called to configure the RtreeConstraint object passed
|
|
** as the second argument for a MATCH constraint. The value passed as the
|
|
** first argument to this function is the right-hand operand to the MATCH
|
|
** operator.
|
|
*/
|
|
static int deserializeGeometry(sqlite3_value *pValue, RtreeConstraint *pCons){
|
|
RtreeMatchArg *p;
|
|
sqlite3_rtree_geometry *pGeom;
|
|
int nBlob;
|
|
|
|
/* Check that value is actually a blob. */
|
|
if( sqlite3_value_type(pValue)!=SQLITE_BLOB ) return SQLITE_ERROR;
|
|
|
|
/* Check that the blob is roughly the right size. */
|
|
nBlob = sqlite3_value_bytes(pValue);
|
|
if( nBlob<(int)sizeof(RtreeMatchArg)
|
|
|| ((nBlob-sizeof(RtreeMatchArg))%sizeof(RtreeDValue))!=0
|
|
){
|
|
return SQLITE_ERROR;
|
|
}
|
|
|
|
pGeom = (sqlite3_rtree_geometry *)sqlite3_malloc(
|
|
sizeof(sqlite3_rtree_geometry) + nBlob
|
|
);
|
|
if( !pGeom ) return SQLITE_NOMEM;
|
|
memset(pGeom, 0, sizeof(sqlite3_rtree_geometry));
|
|
p = (RtreeMatchArg *)&pGeom[1];
|
|
|
|
memcpy(p, sqlite3_value_blob(pValue), nBlob);
|
|
if( p->magic!=RTREE_GEOMETRY_MAGIC
|
|
|| nBlob!=(int)(sizeof(RtreeMatchArg) + (p->nParam-1)*sizeof(RtreeDValue))
|
|
){
|
|
sqlite3_free(pGeom);
|
|
return SQLITE_ERROR;
|
|
}
|
|
|
|
pGeom->pContext = p->pContext;
|
|
pGeom->nParam = p->nParam;
|
|
pGeom->aParam = p->aParam;
|
|
|
|
pCons->xGeom = p->xGeom;
|
|
pCons->pGeom = pGeom;
|
|
return SQLITE_OK;
|
|
}
|
|
|
|
/*
|
|
** Rtree virtual table module xFilter method.
|
|
*/
|
|
static int rtreeFilter(
|
|
sqlite3_vtab_cursor *pVtabCursor,
|
|
int idxNum, const char *idxStr,
|
|
int argc, sqlite3_value **argv
|
|
){
|
|
Rtree *pRtree = (Rtree *)pVtabCursor->pVtab;
|
|
RtreeCursor *pCsr = (RtreeCursor *)pVtabCursor;
|
|
|
|
RtreeNode *pRoot = 0;
|
|
int ii;
|
|
int rc = SQLITE_OK;
|
|
|
|
rtreeReference(pRtree);
|
|
|
|
freeCursorConstraints(pCsr);
|
|
pCsr->iStrategy = idxNum;
|
|
|
|
if( idxNum==1 ){
|
|
/* Special case - lookup by rowid. */
|
|
RtreeNode *pLeaf; /* Leaf on which the required cell resides */
|
|
i64 iRowid = sqlite3_value_int64(argv[0]);
|
|
rc = findLeafNode(pRtree, iRowid, &pLeaf);
|
|
pCsr->pNode = pLeaf;
|
|
if( pLeaf ){
|
|
assert( rc==SQLITE_OK );
|
|
rc = nodeRowidIndex(pRtree, pLeaf, iRowid, &pCsr->iCell);
|
|
}
|
|
}else{
|
|
/* Normal case - r-tree scan. Set up the RtreeCursor.aConstraint array
|
|
** with the configured constraints.
|
|
*/
|
|
if( argc>0 ){
|
|
pCsr->aConstraint = sqlite3_malloc(sizeof(RtreeConstraint)*argc);
|
|
pCsr->nConstraint = argc;
|
|
if( !pCsr->aConstraint ){
|
|
rc = SQLITE_NOMEM;
|
|
}else{
|
|
memset(pCsr->aConstraint, 0, sizeof(RtreeConstraint)*argc);
|
|
assert( (idxStr==0 && argc==0)
|
|
|| (idxStr && (int)strlen(idxStr)==argc*2) );
|
|
for(ii=0; ii<argc; ii++){
|
|
RtreeConstraint *p = &pCsr->aConstraint[ii];
|
|
p->op = idxStr[ii*2];
|
|
p->iCoord = idxStr[ii*2+1]-'a';
|
|
if( p->op==RTREE_MATCH ){
|
|
/* A MATCH operator. The right-hand-side must be a blob that
|
|
** can be cast into an RtreeMatchArg object. One created using
|
|
** an sqlite3_rtree_geometry_callback() SQL user function.
|
|
*/
|
|
rc = deserializeGeometry(argv[ii], p);
|
|
if( rc!=SQLITE_OK ){
|
|
break;
|
|
}
|
|
}else{
|
|
#ifdef SQLITE_RTREE_INT_ONLY
|
|
p->rValue = sqlite3_value_int64(argv[ii]);
|
|
#else
|
|
p->rValue = sqlite3_value_double(argv[ii]);
|
|
#endif
|
|
}
|
|
}
|
|
}
|
|
}
|
|
|
|
if( rc==SQLITE_OK ){
|
|
pCsr->pNode = 0;
|
|
rc = nodeAcquire(pRtree, 1, 0, &pRoot);
|
|
}
|
|
if( rc==SQLITE_OK ){
|
|
int isEof = 1;
|
|
int nCell = NCELL(pRoot);
|
|
pCsr->pNode = pRoot;
|
|
for(pCsr->iCell=0; rc==SQLITE_OK && pCsr->iCell<nCell; pCsr->iCell++){
|
|
assert( pCsr->pNode==pRoot );
|
|
rc = descendToCell(pRtree, pCsr, pRtree->iDepth, &isEof);
|
|
if( !isEof ){
|
|
break;
|
|
}
|
|
}
|
|
if( rc==SQLITE_OK && isEof ){
|
|
assert( pCsr->pNode==pRoot );
|
|
nodeRelease(pRtree, pRoot);
|
|
pCsr->pNode = 0;
|
|
}
|
|
assert( rc!=SQLITE_OK || !pCsr->pNode || pCsr->iCell<NCELL(pCsr->pNode) );
|
|
}
|
|
}
|
|
|
|
rtreeRelease(pRtree);
|
|
return rc;
|
|
}
|
|
|
|
/*
|
|
** Rtree virtual table module xBestIndex method. There are three
|
|
** table scan strategies to choose from (in order from most to
|
|
** least desirable):
|
|
**
|
|
** idxNum idxStr Strategy
|
|
** ------------------------------------------------
|
|
** 1 Unused Direct lookup by rowid.
|
|
** 2 See below R-tree query or full-table scan.
|
|
** ------------------------------------------------
|
|
**
|
|
** If strategy 1 is used, then idxStr is not meaningful. If strategy
|
|
** 2 is used, idxStr is formatted to contain 2 bytes for each
|
|
** constraint used. The first two bytes of idxStr correspond to
|
|
** the constraint in sqlite3_index_info.aConstraintUsage[] with
|
|
** (argvIndex==1) etc.
|
|
**
|
|
** The first of each pair of bytes in idxStr identifies the constraint
|
|
** operator as follows:
|
|
**
|
|
** Operator Byte Value
|
|
** ----------------------
|
|
** = 0x41 ('A')
|
|
** <= 0x42 ('B')
|
|
** < 0x43 ('C')
|
|
** >= 0x44 ('D')
|
|
** > 0x45 ('E')
|
|
** MATCH 0x46 ('F')
|
|
** ----------------------
|
|
**
|
|
** The second of each pair of bytes identifies the coordinate column
|
|
** to which the constraint applies. The leftmost coordinate column
|
|
** is 'a', the second from the left 'b' etc.
|
|
*/
|
|
static int rtreeBestIndex(sqlite3_vtab *tab, sqlite3_index_info *pIdxInfo){
|
|
int rc = SQLITE_OK;
|
|
int ii;
|
|
|
|
int iIdx = 0;
|
|
char zIdxStr[RTREE_MAX_DIMENSIONS*8+1];
|
|
memset(zIdxStr, 0, sizeof(zIdxStr));
|
|
UNUSED_PARAMETER(tab);
|
|
|
|
assert( pIdxInfo->idxStr==0 );
|
|
for(ii=0; ii<pIdxInfo->nConstraint && iIdx<(int)(sizeof(zIdxStr)-1); ii++){
|
|
struct sqlite3_index_constraint *p = &pIdxInfo->aConstraint[ii];
|
|
|
|
if( p->usable && p->iColumn==0 && p->op==SQLITE_INDEX_CONSTRAINT_EQ ){
|
|
/* We have an equality constraint on the rowid. Use strategy 1. */
|
|
int jj;
|
|
for(jj=0; jj<ii; jj++){
|
|
pIdxInfo->aConstraintUsage[jj].argvIndex = 0;
|
|
pIdxInfo->aConstraintUsage[jj].omit = 0;
|
|
}
|
|
pIdxInfo->idxNum = 1;
|
|
pIdxInfo->aConstraintUsage[ii].argvIndex = 1;
|
|
pIdxInfo->aConstraintUsage[jj].omit = 1;
|
|
|
|
/* This strategy involves a two rowid lookups on an B-Tree structures
|
|
** and then a linear search of an R-Tree node. This should be
|
|
** considered almost as quick as a direct rowid lookup (for which
|
|
** sqlite uses an internal cost of 0.0).
|
|
*/
|
|
pIdxInfo->estimatedCost = 10.0;
|
|
return SQLITE_OK;
|
|
}
|
|
|
|
if( p->usable && (p->iColumn>0 || p->op==SQLITE_INDEX_CONSTRAINT_MATCH) ){
|
|
u8 op;
|
|
switch( p->op ){
|
|
case SQLITE_INDEX_CONSTRAINT_EQ: op = RTREE_EQ; break;
|
|
case SQLITE_INDEX_CONSTRAINT_GT: op = RTREE_GT; break;
|
|
case SQLITE_INDEX_CONSTRAINT_LE: op = RTREE_LE; break;
|
|
case SQLITE_INDEX_CONSTRAINT_LT: op = RTREE_LT; break;
|
|
case SQLITE_INDEX_CONSTRAINT_GE: op = RTREE_GE; break;
|
|
default:
|
|
assert( p->op==SQLITE_INDEX_CONSTRAINT_MATCH );
|
|
op = RTREE_MATCH;
|
|
break;
|
|
}
|
|
zIdxStr[iIdx++] = op;
|
|
zIdxStr[iIdx++] = p->iColumn - 1 + 'a';
|
|
pIdxInfo->aConstraintUsage[ii].argvIndex = (iIdx/2);
|
|
pIdxInfo->aConstraintUsage[ii].omit = 1;
|
|
}
|
|
}
|
|
|
|
pIdxInfo->idxNum = 2;
|
|
pIdxInfo->needToFreeIdxStr = 1;
|
|
if( iIdx>0 && 0==(pIdxInfo->idxStr = sqlite3_mprintf("%s", zIdxStr)) ){
|
|
return SQLITE_NOMEM;
|
|
}
|
|
assert( iIdx>=0 );
|
|
pIdxInfo->estimatedCost = (2000000.0 / (double)(iIdx + 1));
|
|
return rc;
|
|
}
|
|
|
|
/*
|
|
** Return the N-dimensional volumn of the cell stored in *p.
|
|
*/
|
|
static RtreeDValue cellArea(Rtree *pRtree, RtreeCell *p){
|
|
RtreeDValue area = (RtreeDValue)1;
|
|
int ii;
|
|
for(ii=0; ii<(pRtree->nDim*2); ii+=2){
|
|
area = (area * (DCOORD(p->aCoord[ii+1]) - DCOORD(p->aCoord[ii])));
|
|
}
|
|
return area;
|
|
}
|
|
|
|
/*
|
|
** Return the margin length of cell p. The margin length is the sum
|
|
** of the objects size in each dimension.
|
|
*/
|
|
static RtreeDValue cellMargin(Rtree *pRtree, RtreeCell *p){
|
|
RtreeDValue margin = (RtreeDValue)0;
|
|
int ii;
|
|
for(ii=0; ii<(pRtree->nDim*2); ii+=2){
|
|
margin += (DCOORD(p->aCoord[ii+1]) - DCOORD(p->aCoord[ii]));
|
|
}
|
|
return margin;
|
|
}
|
|
|
|
/*
|
|
** Store the union of cells p1 and p2 in p1.
|
|
*/
|
|
static void cellUnion(Rtree *pRtree, RtreeCell *p1, RtreeCell *p2){
|
|
int ii;
|
|
if( pRtree->eCoordType==RTREE_COORD_REAL32 ){
|
|
for(ii=0; ii<(pRtree->nDim*2); ii+=2){
|
|
p1->aCoord[ii].f = MIN(p1->aCoord[ii].f, p2->aCoord[ii].f);
|
|
p1->aCoord[ii+1].f = MAX(p1->aCoord[ii+1].f, p2->aCoord[ii+1].f);
|
|
}
|
|
}else{
|
|
for(ii=0; ii<(pRtree->nDim*2); ii+=2){
|
|
p1->aCoord[ii].i = MIN(p1->aCoord[ii].i, p2->aCoord[ii].i);
|
|
p1->aCoord[ii+1].i = MAX(p1->aCoord[ii+1].i, p2->aCoord[ii+1].i);
|
|
}
|
|
}
|
|
}
|
|
|
|
/*
|
|
** Return true if the area covered by p2 is a subset of the area covered
|
|
** by p1. False otherwise.
|
|
*/
|
|
static int cellContains(Rtree *pRtree, RtreeCell *p1, RtreeCell *p2){
|
|
int ii;
|
|
int isInt = (pRtree->eCoordType==RTREE_COORD_INT32);
|
|
for(ii=0; ii<(pRtree->nDim*2); ii+=2){
|
|
RtreeCoord *a1 = &p1->aCoord[ii];
|
|
RtreeCoord *a2 = &p2->aCoord[ii];
|
|
if( (!isInt && (a2[0].f<a1[0].f || a2[1].f>a1[1].f))
|
|
|| ( isInt && (a2[0].i<a1[0].i || a2[1].i>a1[1].i))
|
|
){
|
|
return 0;
|
|
}
|
|
}
|
|
return 1;
|
|
}
|
|
|
|
/*
|
|
** Return the amount cell p would grow by if it were unioned with pCell.
|
|
*/
|
|
static RtreeDValue cellGrowth(Rtree *pRtree, RtreeCell *p, RtreeCell *pCell){
|
|
RtreeDValue area;
|
|
RtreeCell cell;
|
|
memcpy(&cell, p, sizeof(RtreeCell));
|
|
area = cellArea(pRtree, &cell);
|
|
cellUnion(pRtree, &cell, pCell);
|
|
return (cellArea(pRtree, &cell)-area);
|
|
}
|
|
|
|
#if VARIANT_RSTARTREE_CHOOSESUBTREE || VARIANT_RSTARTREE_SPLIT
|
|
static RtreeDValue cellOverlap(
|
|
Rtree *pRtree,
|
|
RtreeCell *p,
|
|
RtreeCell *aCell,
|
|
int nCell,
|
|
int iExclude
|
|
){
|
|
int ii;
|
|
RtreeDValue overlap = 0.0;
|
|
for(ii=0; ii<nCell; ii++){
|
|
#if VARIANT_RSTARTREE_CHOOSESUBTREE
|
|
if( ii!=iExclude )
|
|
#else
|
|
assert( iExclude==-1 );
|
|
UNUSED_PARAMETER(iExclude);
|
|
#endif
|
|
{
|
|
int jj;
|
|
RtreeDValue o = (RtreeDValue)1;
|
|
for(jj=0; jj<(pRtree->nDim*2); jj+=2){
|
|
RtreeDValue x1, x2;
|
|
|
|
x1 = MAX(DCOORD(p->aCoord[jj]), DCOORD(aCell[ii].aCoord[jj]));
|
|
x2 = MIN(DCOORD(p->aCoord[jj+1]), DCOORD(aCell[ii].aCoord[jj+1]));
|
|
|
|
if( x2<x1 ){
|
|
o = 0.0;
|
|
break;
|
|
}else{
|
|
o = o * (x2-x1);
|
|
}
|
|
}
|
|
overlap += o;
|
|
}
|
|
}
|
|
return overlap;
|
|
}
|
|
#endif
|
|
|
|
#if VARIANT_RSTARTREE_CHOOSESUBTREE
|
|
static RtreeDValue cellOverlapEnlargement(
|
|
Rtree *pRtree,
|
|
RtreeCell *p,
|
|
RtreeCell *pInsert,
|
|
RtreeCell *aCell,
|
|
int nCell,
|
|
int iExclude
|
|
){
|
|
RtreeDValue before, after;
|
|
before = cellOverlap(pRtree, p, aCell, nCell, iExclude);
|
|
cellUnion(pRtree, p, pInsert);
|
|
after = cellOverlap(pRtree, p, aCell, nCell, iExclude);
|
|
return (after-before);
|
|
}
|
|
#endif
|
|
|
|
|
|
/*
|
|
** This function implements the ChooseLeaf algorithm from Gutman[84].
|
|
** ChooseSubTree in r*tree terminology.
|
|
*/
|
|
static int ChooseLeaf(
|
|
Rtree *pRtree, /* Rtree table */
|
|
RtreeCell *pCell, /* Cell to insert into rtree */
|
|
int iHeight, /* Height of sub-tree rooted at pCell */
|
|
RtreeNode **ppLeaf /* OUT: Selected leaf page */
|
|
){
|
|
int rc;
|
|
int ii;
|
|
RtreeNode *pNode;
|
|
rc = nodeAcquire(pRtree, 1, 0, &pNode);
|
|
|
|
for(ii=0; rc==SQLITE_OK && ii<(pRtree->iDepth-iHeight); ii++){
|
|
int iCell;
|
|
sqlite3_int64 iBest = 0;
|
|
|
|
RtreeDValue fMinGrowth = 0.0;
|
|
RtreeDValue fMinArea = 0.0;
|
|
#if VARIANT_RSTARTREE_CHOOSESUBTREE
|
|
RtreeDValue fMinOverlap = 0.0;
|
|
RtreeDValue overlap;
|
|
#endif
|
|
|
|
int nCell = NCELL(pNode);
|
|
RtreeCell cell;
|
|
RtreeNode *pChild;
|
|
|
|
RtreeCell *aCell = 0;
|
|
|
|
#if VARIANT_RSTARTREE_CHOOSESUBTREE
|
|
if( ii==(pRtree->iDepth-1) ){
|
|
int jj;
|
|
aCell = sqlite3_malloc(sizeof(RtreeCell)*nCell);
|
|
if( !aCell ){
|
|
rc = SQLITE_NOMEM;
|
|
nodeRelease(pRtree, pNode);
|
|
pNode = 0;
|
|
continue;
|
|
}
|
|
for(jj=0; jj<nCell; jj++){
|
|
nodeGetCell(pRtree, pNode, jj, &aCell[jj]);
|
|
}
|
|
}
|
|
#endif
|
|
|
|
/* Select the child node which will be enlarged the least if pCell
|
|
** is inserted into it. Resolve ties by choosing the entry with
|
|
** the smallest area.
|
|
*/
|
|
for(iCell=0; iCell<nCell; iCell++){
|
|
int bBest = 0;
|
|
RtreeDValue growth;
|
|
RtreeDValue area;
|
|
nodeGetCell(pRtree, pNode, iCell, &cell);
|
|
growth = cellGrowth(pRtree, &cell, pCell);
|
|
area = cellArea(pRtree, &cell);
|
|
|
|
#if VARIANT_RSTARTREE_CHOOSESUBTREE
|
|
if( ii==(pRtree->iDepth-1) ){
|
|
overlap = cellOverlapEnlargement(pRtree,&cell,pCell,aCell,nCell,iCell);
|
|
}else{
|
|
overlap = 0.0;
|
|
}
|
|
if( (iCell==0)
|
|
|| (overlap<fMinOverlap)
|
|
|| (overlap==fMinOverlap && growth<fMinGrowth)
|
|
|| (overlap==fMinOverlap && growth==fMinGrowth && area<fMinArea)
|
|
){
|
|
bBest = 1;
|
|
fMinOverlap = overlap;
|
|
}
|
|
#else
|
|
if( iCell==0||growth<fMinGrowth||(growth==fMinGrowth && area<fMinArea) ){
|
|
bBest = 1;
|
|
}
|
|
#endif
|
|
if( bBest ){
|
|
fMinGrowth = growth;
|
|
fMinArea = area;
|
|
iBest = cell.iRowid;
|
|
}
|
|
}
|
|
|
|
sqlite3_free(aCell);
|
|
rc = nodeAcquire(pRtree, iBest, pNode, &pChild);
|
|
nodeRelease(pRtree, pNode);
|
|
pNode = pChild;
|
|
}
|
|
|
|
*ppLeaf = pNode;
|
|
return rc;
|
|
}
|
|
|
|
/*
|
|
** A cell with the same content as pCell has just been inserted into
|
|
** the node pNode. This function updates the bounding box cells in
|
|
** all ancestor elements.
|
|
*/
|
|
static int AdjustTree(
|
|
Rtree *pRtree, /* Rtree table */
|
|
RtreeNode *pNode, /* Adjust ancestry of this node. */
|
|
RtreeCell *pCell /* This cell was just inserted */
|
|
){
|
|
RtreeNode *p = pNode;
|
|
while( p->pParent ){
|
|
RtreeNode *pParent = p->pParent;
|
|
RtreeCell cell;
|
|
int iCell;
|
|
|
|
if( nodeParentIndex(pRtree, p, &iCell) ){
|
|
return SQLITE_CORRUPT_VTAB;
|
|
}
|
|
|
|
nodeGetCell(pRtree, pParent, iCell, &cell);
|
|
if( !cellContains(pRtree, &cell, pCell) ){
|
|
cellUnion(pRtree, &cell, pCell);
|
|
nodeOverwriteCell(pRtree, pParent, &cell, iCell);
|
|
}
|
|
|
|
p = pParent;
|
|
}
|
|
return SQLITE_OK;
|
|
}
|
|
|
|
/*
|
|
** Write mapping (iRowid->iNode) to the <rtree>_rowid table.
|
|
*/
|
|
static int rowidWrite(Rtree *pRtree, sqlite3_int64 iRowid, sqlite3_int64 iNode){
|
|
sqlite3_bind_int64(pRtree->pWriteRowid, 1, iRowid);
|
|
sqlite3_bind_int64(pRtree->pWriteRowid, 2, iNode);
|
|
sqlite3_step(pRtree->pWriteRowid);
|
|
return sqlite3_reset(pRtree->pWriteRowid);
|
|
}
|
|
|
|
/*
|
|
** Write mapping (iNode->iPar) to the <rtree>_parent table.
|
|
*/
|
|
static int parentWrite(Rtree *pRtree, sqlite3_int64 iNode, sqlite3_int64 iPar){
|
|
sqlite3_bind_int64(pRtree->pWriteParent, 1, iNode);
|
|
sqlite3_bind_int64(pRtree->pWriteParent, 2, iPar);
|
|
sqlite3_step(pRtree->pWriteParent);
|
|
return sqlite3_reset(pRtree->pWriteParent);
|
|
}
|
|
|
|
static int rtreeInsertCell(Rtree *, RtreeNode *, RtreeCell *, int);
|
|
|
|
#if VARIANT_GUTTMAN_LINEAR_SPLIT
|
|
/*
|
|
** Implementation of the linear variant of the PickNext() function from
|
|
** Guttman[84].
|
|
*/
|
|
static RtreeCell *LinearPickNext(
|
|
Rtree *pRtree,
|
|
RtreeCell *aCell,
|
|
int nCell,
|
|
RtreeCell *pLeftBox,
|
|
RtreeCell *pRightBox,
|
|
int *aiUsed
|
|
){
|
|
int ii;
|
|
for(ii=0; aiUsed[ii]; ii++);
|
|
aiUsed[ii] = 1;
|
|
return &aCell[ii];
|
|
}
|
|
|
|
/*
|
|
** Implementation of the linear variant of the PickSeeds() function from
|
|
** Guttman[84].
|
|
*/
|
|
static void LinearPickSeeds(
|
|
Rtree *pRtree,
|
|
RtreeCell *aCell,
|
|
int nCell,
|
|
int *piLeftSeed,
|
|
int *piRightSeed
|
|
){
|
|
int i;
|
|
int iLeftSeed = 0;
|
|
int iRightSeed = 1;
|
|
RtreeDValue maxNormalInnerWidth = (RtreeDValue)0;
|
|
|
|
/* Pick two "seed" cells from the array of cells. The algorithm used
|
|
** here is the LinearPickSeeds algorithm from Gutman[1984]. The
|
|
** indices of the two seed cells in the array are stored in local
|
|
** variables iLeftSeek and iRightSeed.
|
|
*/
|
|
for(i=0; i<pRtree->nDim; i++){
|
|
RtreeDValue x1 = DCOORD(aCell[0].aCoord[i*2]);
|
|
RtreeDValue x2 = DCOORD(aCell[0].aCoord[i*2+1]);
|
|
RtreeDValue x3 = x1;
|
|
RtreeDValue x4 = x2;
|
|
int jj;
|
|
|
|
int iCellLeft = 0;
|
|
int iCellRight = 0;
|
|
|
|
for(jj=1; jj<nCell; jj++){
|
|
RtreeDValue left = DCOORD(aCell[jj].aCoord[i*2]);
|
|
RtreeDValue right = DCOORD(aCell[jj].aCoord[i*2+1]);
|
|
|
|
if( left<x1 ) x1 = left;
|
|
if( right>x4 ) x4 = right;
|
|
if( left>x3 ){
|
|
x3 = left;
|
|
iCellRight = jj;
|
|
}
|
|
if( right<x2 ){
|
|
x2 = right;
|
|
iCellLeft = jj;
|
|
}
|
|
}
|
|
|
|
if( x4!=x1 ){
|
|
RtreeDValue normalwidth = (x3 - x2) / (x4 - x1);
|
|
if( normalwidth>maxNormalInnerWidth ){
|
|
iLeftSeed = iCellLeft;
|
|
iRightSeed = iCellRight;
|
|
}
|
|
}
|
|
}
|
|
|
|
*piLeftSeed = iLeftSeed;
|
|
*piRightSeed = iRightSeed;
|
|
}
|
|
#endif /* VARIANT_GUTTMAN_LINEAR_SPLIT */
|
|
|
|
#if VARIANT_GUTTMAN_QUADRATIC_SPLIT
|
|
/*
|
|
** Implementation of the quadratic variant of the PickNext() function from
|
|
** Guttman[84].
|
|
*/
|
|
static RtreeCell *QuadraticPickNext(
|
|
Rtree *pRtree,
|
|
RtreeCell *aCell,
|
|
int nCell,
|
|
RtreeCell *pLeftBox,
|
|
RtreeCell *pRightBox,
|
|
int *aiUsed
|
|
){
|
|
#define FABS(a) ((a)<0.0?-1.0*(a):(a))
|
|
|
|
int iSelect = -1;
|
|
RtreeDValue fDiff;
|
|
int ii;
|
|
for(ii=0; ii<nCell; ii++){
|
|
if( aiUsed[ii]==0 ){
|
|
RtreeDValue left = cellGrowth(pRtree, pLeftBox, &aCell[ii]);
|
|
RtreeDValue right = cellGrowth(pRtree, pLeftBox, &aCell[ii]);
|
|
RtreeDValue diff = FABS(right-left);
|
|
if( iSelect<0 || diff>fDiff ){
|
|
fDiff = diff;
|
|
iSelect = ii;
|
|
}
|
|
}
|
|
}
|
|
aiUsed[iSelect] = 1;
|
|
return &aCell[iSelect];
|
|
}
|
|
|
|
/*
|
|
** Implementation of the quadratic variant of the PickSeeds() function from
|
|
** Guttman[84].
|
|
*/
|
|
static void QuadraticPickSeeds(
|
|
Rtree *pRtree,
|
|
RtreeCell *aCell,
|
|
int nCell,
|
|
int *piLeftSeed,
|
|
int *piRightSeed
|
|
){
|
|
int ii;
|
|
int jj;
|
|
|
|
int iLeftSeed = 0;
|
|
int iRightSeed = 1;
|
|
RtreeDValue fWaste = 0.0;
|
|
|
|
for(ii=0; ii<nCell; ii++){
|
|
for(jj=ii+1; jj<nCell; jj++){
|
|
RtreeDValue right = cellArea(pRtree, &aCell[jj]);
|
|
RtreeDValue growth = cellGrowth(pRtree, &aCell[ii], &aCell[jj]);
|
|
RtreeDValue waste = growth - right;
|
|
|
|
if( waste>fWaste ){
|
|
iLeftSeed = ii;
|
|
iRightSeed = jj;
|
|
fWaste = waste;
|
|
}
|
|
}
|
|
}
|
|
|
|
*piLeftSeed = iLeftSeed;
|
|
*piRightSeed = iRightSeed;
|
|
}
|
|
#endif /* VARIANT_GUTTMAN_QUADRATIC_SPLIT */
|
|
|
|
/*
|
|
** Arguments aIdx, aDistance and aSpare all point to arrays of size
|
|
** nIdx. The aIdx array contains the set of integers from 0 to
|
|
** (nIdx-1) in no particular order. This function sorts the values
|
|
** in aIdx according to the indexed values in aDistance. For
|
|
** example, assuming the inputs:
|
|
**
|
|
** aIdx = { 0, 1, 2, 3 }
|
|
** aDistance = { 5.0, 2.0, 7.0, 6.0 }
|
|
**
|
|
** this function sets the aIdx array to contain:
|
|
**
|
|
** aIdx = { 0, 1, 2, 3 }
|
|
**
|
|
** The aSpare array is used as temporary working space by the
|
|
** sorting algorithm.
|
|
*/
|
|
static void SortByDistance(
|
|
int *aIdx,
|
|
int nIdx,
|
|
RtreeDValue *aDistance,
|
|
int *aSpare
|
|
){
|
|
if( nIdx>1 ){
|
|
int iLeft = 0;
|
|
int iRight = 0;
|
|
|
|
int nLeft = nIdx/2;
|
|
int nRight = nIdx-nLeft;
|
|
int *aLeft = aIdx;
|
|
int *aRight = &aIdx[nLeft];
|
|
|
|
SortByDistance(aLeft, nLeft, aDistance, aSpare);
|
|
SortByDistance(aRight, nRight, aDistance, aSpare);
|
|
|
|
memcpy(aSpare, aLeft, sizeof(int)*nLeft);
|
|
aLeft = aSpare;
|
|
|
|
while( iLeft<nLeft || iRight<nRight ){
|
|
if( iLeft==nLeft ){
|
|
aIdx[iLeft+iRight] = aRight[iRight];
|
|
iRight++;
|
|
}else if( iRight==nRight ){
|
|
aIdx[iLeft+iRight] = aLeft[iLeft];
|
|
iLeft++;
|
|
}else{
|
|
RtreeDValue fLeft = aDistance[aLeft[iLeft]];
|
|
RtreeDValue fRight = aDistance[aRight[iRight]];
|
|
if( fLeft<fRight ){
|
|
aIdx[iLeft+iRight] = aLeft[iLeft];
|
|
iLeft++;
|
|
}else{
|
|
aIdx[iLeft+iRight] = aRight[iRight];
|
|
iRight++;
|
|
}
|
|
}
|
|
}
|
|
|
|
#if 0
|
|
/* Check that the sort worked */
|
|
{
|
|
int jj;
|
|
for(jj=1; jj<nIdx; jj++){
|
|
RtreeDValue left = aDistance[aIdx[jj-1]];
|
|
RtreeDValue right = aDistance[aIdx[jj]];
|
|
assert( left<=right );
|
|
}
|
|
}
|
|
#endif
|
|
}
|
|
}
|
|
|
|
/*
|
|
** Arguments aIdx, aCell and aSpare all point to arrays of size
|
|
** nIdx. The aIdx array contains the set of integers from 0 to
|
|
** (nIdx-1) in no particular order. This function sorts the values
|
|
** in aIdx according to dimension iDim of the cells in aCell. The
|
|
** minimum value of dimension iDim is considered first, the
|
|
** maximum used to break ties.
|
|
**
|
|
** The aSpare array is used as temporary working space by the
|
|
** sorting algorithm.
|
|
*/
|
|
static void SortByDimension(
|
|
Rtree *pRtree,
|
|
int *aIdx,
|
|
int nIdx,
|
|
int iDim,
|
|
RtreeCell *aCell,
|
|
int *aSpare
|
|
){
|
|
if( nIdx>1 ){
|
|
|
|
int iLeft = 0;
|
|
int iRight = 0;
|
|
|
|
int nLeft = nIdx/2;
|
|
int nRight = nIdx-nLeft;
|
|
int *aLeft = aIdx;
|
|
int *aRight = &aIdx[nLeft];
|
|
|
|
SortByDimension(pRtree, aLeft, nLeft, iDim, aCell, aSpare);
|
|
SortByDimension(pRtree, aRight, nRight, iDim, aCell, aSpare);
|
|
|
|
memcpy(aSpare, aLeft, sizeof(int)*nLeft);
|
|
aLeft = aSpare;
|
|
while( iLeft<nLeft || iRight<nRight ){
|
|
RtreeDValue xleft1 = DCOORD(aCell[aLeft[iLeft]].aCoord[iDim*2]);
|
|
RtreeDValue xleft2 = DCOORD(aCell[aLeft[iLeft]].aCoord[iDim*2+1]);
|
|
RtreeDValue xright1 = DCOORD(aCell[aRight[iRight]].aCoord[iDim*2]);
|
|
RtreeDValue xright2 = DCOORD(aCell[aRight[iRight]].aCoord[iDim*2+1]);
|
|
if( (iLeft!=nLeft) && ((iRight==nRight)
|
|
|| (xleft1<xright1)
|
|
|| (xleft1==xright1 && xleft2<xright2)
|
|
)){
|
|
aIdx[iLeft+iRight] = aLeft[iLeft];
|
|
iLeft++;
|
|
}else{
|
|
aIdx[iLeft+iRight] = aRight[iRight];
|
|
iRight++;
|
|
}
|
|
}
|
|
|
|
#if 0
|
|
/* Check that the sort worked */
|
|
{
|
|
int jj;
|
|
for(jj=1; jj<nIdx; jj++){
|
|
RtreeDValue xleft1 = aCell[aIdx[jj-1]].aCoord[iDim*2];
|
|
RtreeDValue xleft2 = aCell[aIdx[jj-1]].aCoord[iDim*2+1];
|
|
RtreeDValue xright1 = aCell[aIdx[jj]].aCoord[iDim*2];
|
|
RtreeDValue xright2 = aCell[aIdx[jj]].aCoord[iDim*2+1];
|
|
assert( xleft1<=xright1 && (xleft1<xright1 || xleft2<=xright2) );
|
|
}
|
|
}
|
|
#endif
|
|
}
|
|
}
|
|
|
|
#if VARIANT_RSTARTREE_SPLIT
|
|
/*
|
|
** Implementation of the R*-tree variant of SplitNode from Beckman[1990].
|
|
*/
|
|
static int splitNodeStartree(
|
|
Rtree *pRtree,
|
|
RtreeCell *aCell,
|
|
int nCell,
|
|
RtreeNode *pLeft,
|
|
RtreeNode *pRight,
|
|
RtreeCell *pBboxLeft,
|
|
RtreeCell *pBboxRight
|
|
){
|
|
int **aaSorted;
|
|
int *aSpare;
|
|
int ii;
|
|
|
|
int iBestDim = 0;
|
|
int iBestSplit = 0;
|
|
RtreeDValue fBestMargin = 0.0;
|
|
|
|
int nByte = (pRtree->nDim+1)*(sizeof(int*)+nCell*sizeof(int));
|
|
|
|
aaSorted = (int **)sqlite3_malloc(nByte);
|
|
if( !aaSorted ){
|
|
return SQLITE_NOMEM;
|
|
}
|
|
|
|
aSpare = &((int *)&aaSorted[pRtree->nDim])[pRtree->nDim*nCell];
|
|
memset(aaSorted, 0, nByte);
|
|
for(ii=0; ii<pRtree->nDim; ii++){
|
|
int jj;
|
|
aaSorted[ii] = &((int *)&aaSorted[pRtree->nDim])[ii*nCell];
|
|
for(jj=0; jj<nCell; jj++){
|
|
aaSorted[ii][jj] = jj;
|
|
}
|
|
SortByDimension(pRtree, aaSorted[ii], nCell, ii, aCell, aSpare);
|
|
}
|
|
|
|
for(ii=0; ii<pRtree->nDim; ii++){
|
|
RtreeDValue margin = 0.0;
|
|
RtreeDValue fBestOverlap = 0.0;
|
|
RtreeDValue fBestArea = 0.0;
|
|
int iBestLeft = 0;
|
|
int nLeft;
|
|
|
|
for(
|
|
nLeft=RTREE_MINCELLS(pRtree);
|
|
nLeft<=(nCell-RTREE_MINCELLS(pRtree));
|
|
nLeft++
|
|
){
|
|
RtreeCell left;
|
|
RtreeCell right;
|
|
int kk;
|
|
RtreeDValue overlap;
|
|
RtreeDValue area;
|
|
|
|
memcpy(&left, &aCell[aaSorted[ii][0]], sizeof(RtreeCell));
|
|
memcpy(&right, &aCell[aaSorted[ii][nCell-1]], sizeof(RtreeCell));
|
|
for(kk=1; kk<(nCell-1); kk++){
|
|
if( kk<nLeft ){
|
|
cellUnion(pRtree, &left, &aCell[aaSorted[ii][kk]]);
|
|
}else{
|
|
cellUnion(pRtree, &right, &aCell[aaSorted[ii][kk]]);
|
|
}
|
|
}
|
|
margin += cellMargin(pRtree, &left);
|
|
margin += cellMargin(pRtree, &right);
|
|
overlap = cellOverlap(pRtree, &left, &right, 1, -1);
|
|
area = cellArea(pRtree, &left) + cellArea(pRtree, &right);
|
|
if( (nLeft==RTREE_MINCELLS(pRtree))
|
|
|| (overlap<fBestOverlap)
|
|
|| (overlap==fBestOverlap && area<fBestArea)
|
|
){
|
|
iBestLeft = nLeft;
|
|
fBestOverlap = overlap;
|
|
fBestArea = area;
|
|
}
|
|
}
|
|
|
|
if( ii==0 || margin<fBestMargin ){
|
|
iBestDim = ii;
|
|
fBestMargin = margin;
|
|
iBestSplit = iBestLeft;
|
|
}
|
|
}
|
|
|
|
memcpy(pBboxLeft, &aCell[aaSorted[iBestDim][0]], sizeof(RtreeCell));
|
|
memcpy(pBboxRight, &aCell[aaSorted[iBestDim][iBestSplit]], sizeof(RtreeCell));
|
|
for(ii=0; ii<nCell; ii++){
|
|
RtreeNode *pTarget = (ii<iBestSplit)?pLeft:pRight;
|
|
RtreeCell *pBbox = (ii<iBestSplit)?pBboxLeft:pBboxRight;
|
|
RtreeCell *pCell = &aCell[aaSorted[iBestDim][ii]];
|
|
nodeInsertCell(pRtree, pTarget, pCell);
|
|
cellUnion(pRtree, pBbox, pCell);
|
|
}
|
|
|
|
sqlite3_free(aaSorted);
|
|
return SQLITE_OK;
|
|
}
|
|
#endif
|
|
|
|
#if VARIANT_GUTTMAN_SPLIT
|
|
/*
|
|
** Implementation of the regular R-tree SplitNode from Guttman[1984].
|
|
*/
|
|
static int splitNodeGuttman(
|
|
Rtree *pRtree,
|
|
RtreeCell *aCell,
|
|
int nCell,
|
|
RtreeNode *pLeft,
|
|
RtreeNode *pRight,
|
|
RtreeCell *pBboxLeft,
|
|
RtreeCell *pBboxRight
|
|
){
|
|
int iLeftSeed = 0;
|
|
int iRightSeed = 1;
|
|
int *aiUsed;
|
|
int i;
|
|
|
|
aiUsed = sqlite3_malloc(sizeof(int)*nCell);
|
|
if( !aiUsed ){
|
|
return SQLITE_NOMEM;
|
|
}
|
|
memset(aiUsed, 0, sizeof(int)*nCell);
|
|
|
|
PickSeeds(pRtree, aCell, nCell, &iLeftSeed, &iRightSeed);
|
|
|
|
memcpy(pBboxLeft, &aCell[iLeftSeed], sizeof(RtreeCell));
|
|
memcpy(pBboxRight, &aCell[iRightSeed], sizeof(RtreeCell));
|
|
nodeInsertCell(pRtree, pLeft, &aCell[iLeftSeed]);
|
|
nodeInsertCell(pRtree, pRight, &aCell[iRightSeed]);
|
|
aiUsed[iLeftSeed] = 1;
|
|
aiUsed[iRightSeed] = 1;
|
|
|
|
for(i=nCell-2; i>0; i--){
|
|
RtreeCell *pNext;
|
|
pNext = PickNext(pRtree, aCell, nCell, pBboxLeft, pBboxRight, aiUsed);
|
|
RtreeDValue diff =
|
|
cellGrowth(pRtree, pBboxLeft, pNext) -
|
|
cellGrowth(pRtree, pBboxRight, pNext)
|
|
;
|
|
if( (RTREE_MINCELLS(pRtree)-NCELL(pRight)==i)
|
|
|| (diff>0.0 && (RTREE_MINCELLS(pRtree)-NCELL(pLeft)!=i))
|
|
){
|
|
nodeInsertCell(pRtree, pRight, pNext);
|
|
cellUnion(pRtree, pBboxRight, pNext);
|
|
}else{
|
|
nodeInsertCell(pRtree, pLeft, pNext);
|
|
cellUnion(pRtree, pBboxLeft, pNext);
|
|
}
|
|
}
|
|
|
|
sqlite3_free(aiUsed);
|
|
return SQLITE_OK;
|
|
}
|
|
#endif
|
|
|
|
static int updateMapping(
|
|
Rtree *pRtree,
|
|
i64 iRowid,
|
|
RtreeNode *pNode,
|
|
int iHeight
|
|
){
|
|
int (*xSetMapping)(Rtree *, sqlite3_int64, sqlite3_int64);
|
|
xSetMapping = ((iHeight==0)?rowidWrite:parentWrite);
|
|
if( iHeight>0 ){
|
|
RtreeNode *pChild = nodeHashLookup(pRtree, iRowid);
|
|
if( pChild ){
|
|
nodeRelease(pRtree, pChild->pParent);
|
|
nodeReference(pNode);
|
|
pChild->pParent = pNode;
|
|
}
|
|
}
|
|
return xSetMapping(pRtree, iRowid, pNode->iNode);
|
|
}
|
|
|
|
static int SplitNode(
|
|
Rtree *pRtree,
|
|
RtreeNode *pNode,
|
|
RtreeCell *pCell,
|
|
int iHeight
|
|
){
|
|
int i;
|
|
int newCellIsRight = 0;
|
|
|
|
int rc = SQLITE_OK;
|
|
int nCell = NCELL(pNode);
|
|
RtreeCell *aCell;
|
|
int *aiUsed;
|
|
|
|
RtreeNode *pLeft = 0;
|
|
RtreeNode *pRight = 0;
|
|
|
|
RtreeCell leftbbox;
|
|
RtreeCell rightbbox;
|
|
|
|
/* Allocate an array and populate it with a copy of pCell and
|
|
** all cells from node pLeft. Then zero the original node.
|
|
*/
|
|
aCell = sqlite3_malloc((sizeof(RtreeCell)+sizeof(int))*(nCell+1));
|
|
if( !aCell ){
|
|
rc = SQLITE_NOMEM;
|
|
goto splitnode_out;
|
|
}
|
|
aiUsed = (int *)&aCell[nCell+1];
|
|
memset(aiUsed, 0, sizeof(int)*(nCell+1));
|
|
for(i=0; i<nCell; i++){
|
|
nodeGetCell(pRtree, pNode, i, &aCell[i]);
|
|
}
|
|
nodeZero(pRtree, pNode);
|
|
memcpy(&aCell[nCell], pCell, sizeof(RtreeCell));
|
|
nCell++;
|
|
|
|
if( pNode->iNode==1 ){
|
|
pRight = nodeNew(pRtree, pNode);
|
|
pLeft = nodeNew(pRtree, pNode);
|
|
pRtree->iDepth++;
|
|
pNode->isDirty = 1;
|
|
writeInt16(pNode->zData, pRtree->iDepth);
|
|
}else{
|
|
pLeft = pNode;
|
|
pRight = nodeNew(pRtree, pLeft->pParent);
|
|
nodeReference(pLeft);
|
|
}
|
|
|
|
if( !pLeft || !pRight ){
|
|
rc = SQLITE_NOMEM;
|
|
goto splitnode_out;
|
|
}
|
|
|
|
memset(pLeft->zData, 0, pRtree->iNodeSize);
|
|
memset(pRight->zData, 0, pRtree->iNodeSize);
|
|
|
|
rc = AssignCells(pRtree, aCell, nCell, pLeft, pRight, &leftbbox, &rightbbox);
|
|
if( rc!=SQLITE_OK ){
|
|
goto splitnode_out;
|
|
}
|
|
|
|
/* Ensure both child nodes have node numbers assigned to them by calling
|
|
** nodeWrite(). Node pRight always needs a node number, as it was created
|
|
** by nodeNew() above. But node pLeft sometimes already has a node number.
|
|
** In this case avoid the all to nodeWrite().
|
|
*/
|
|
if( SQLITE_OK!=(rc = nodeWrite(pRtree, pRight))
|
|
|| (0==pLeft->iNode && SQLITE_OK!=(rc = nodeWrite(pRtree, pLeft)))
|
|
){
|
|
goto splitnode_out;
|
|
}
|
|
|
|
rightbbox.iRowid = pRight->iNode;
|
|
leftbbox.iRowid = pLeft->iNode;
|
|
|
|
if( pNode->iNode==1 ){
|
|
rc = rtreeInsertCell(pRtree, pLeft->pParent, &leftbbox, iHeight+1);
|
|
if( rc!=SQLITE_OK ){
|
|
goto splitnode_out;
|
|
}
|
|
}else{
|
|
RtreeNode *pParent = pLeft->pParent;
|
|
int iCell;
|
|
rc = nodeParentIndex(pRtree, pLeft, &iCell);
|
|
if( rc==SQLITE_OK ){
|
|
nodeOverwriteCell(pRtree, pParent, &leftbbox, iCell);
|
|
rc = AdjustTree(pRtree, pParent, &leftbbox);
|
|
}
|
|
if( rc!=SQLITE_OK ){
|
|
goto splitnode_out;
|
|
}
|
|
}
|
|
if( (rc = rtreeInsertCell(pRtree, pRight->pParent, &rightbbox, iHeight+1)) ){
|
|
goto splitnode_out;
|
|
}
|
|
|
|
for(i=0; i<NCELL(pRight); i++){
|
|
i64 iRowid = nodeGetRowid(pRtree, pRight, i);
|
|
rc = updateMapping(pRtree, iRowid, pRight, iHeight);
|
|
if( iRowid==pCell->iRowid ){
|
|
newCellIsRight = 1;
|
|
}
|
|
if( rc!=SQLITE_OK ){
|
|
goto splitnode_out;
|
|
}
|
|
}
|
|
if( pNode->iNode==1 ){
|
|
for(i=0; i<NCELL(pLeft); i++){
|
|
i64 iRowid = nodeGetRowid(pRtree, pLeft, i);
|
|
rc = updateMapping(pRtree, iRowid, pLeft, iHeight);
|
|
if( rc!=SQLITE_OK ){
|
|
goto splitnode_out;
|
|
}
|
|
}
|
|
}else if( newCellIsRight==0 ){
|
|
rc = updateMapping(pRtree, pCell->iRowid, pLeft, iHeight);
|
|
}
|
|
|
|
if( rc==SQLITE_OK ){
|
|
rc = nodeRelease(pRtree, pRight);
|
|
pRight = 0;
|
|
}
|
|
if( rc==SQLITE_OK ){
|
|
rc = nodeRelease(pRtree, pLeft);
|
|
pLeft = 0;
|
|
}
|
|
|
|
splitnode_out:
|
|
nodeRelease(pRtree, pRight);
|
|
nodeRelease(pRtree, pLeft);
|
|
sqlite3_free(aCell);
|
|
return rc;
|
|
}
|
|
|
|
/*
|
|
** If node pLeaf is not the root of the r-tree and its pParent pointer is
|
|
** still NULL, load all ancestor nodes of pLeaf into memory and populate
|
|
** the pLeaf->pParent chain all the way up to the root node.
|
|
**
|
|
** This operation is required when a row is deleted (or updated - an update
|
|
** is implemented as a delete followed by an insert). SQLite provides the
|
|
** rowid of the row to delete, which can be used to find the leaf on which
|
|
** the entry resides (argument pLeaf). Once the leaf is located, this
|
|
** function is called to determine its ancestry.
|
|
*/
|
|
static int fixLeafParent(Rtree *pRtree, RtreeNode *pLeaf){
|
|
int rc = SQLITE_OK;
|
|
RtreeNode *pChild = pLeaf;
|
|
while( rc==SQLITE_OK && pChild->iNode!=1 && pChild->pParent==0 ){
|
|
int rc2 = SQLITE_OK; /* sqlite3_reset() return code */
|
|
sqlite3_bind_int64(pRtree->pReadParent, 1, pChild->iNode);
|
|
rc = sqlite3_step(pRtree->pReadParent);
|
|
if( rc==SQLITE_ROW ){
|
|
RtreeNode *pTest; /* Used to test for reference loops */
|
|
i64 iNode; /* Node number of parent node */
|
|
|
|
/* Before setting pChild->pParent, test that we are not creating a
|
|
** loop of references (as we would if, say, pChild==pParent). We don't
|
|
** want to do this as it leads to a memory leak when trying to delete
|
|
** the referenced counted node structures.
|
|
*/
|
|
iNode = sqlite3_column_int64(pRtree->pReadParent, 0);
|
|
for(pTest=pLeaf; pTest && pTest->iNode!=iNode; pTest=pTest->pParent);
|
|
if( !pTest ){
|
|
rc2 = nodeAcquire(pRtree, iNode, 0, &pChild->pParent);
|
|
}
|
|
}
|
|
rc = sqlite3_reset(pRtree->pReadParent);
|
|
if( rc==SQLITE_OK ) rc = rc2;
|
|
if( rc==SQLITE_OK && !pChild->pParent ) rc = SQLITE_CORRUPT_VTAB;
|
|
pChild = pChild->pParent;
|
|
}
|
|
return rc;
|
|
}
|
|
|
|
static int deleteCell(Rtree *, RtreeNode *, int, int);
|
|
|
|
static int removeNode(Rtree *pRtree, RtreeNode *pNode, int iHeight){
|
|
int rc;
|
|
int rc2;
|
|
RtreeNode *pParent = 0;
|
|
int iCell;
|
|
|
|
assert( pNode->nRef==1 );
|
|
|
|
/* Remove the entry in the parent cell. */
|
|
rc = nodeParentIndex(pRtree, pNode, &iCell);
|
|
if( rc==SQLITE_OK ){
|
|
pParent = pNode->pParent;
|
|
pNode->pParent = 0;
|
|
rc = deleteCell(pRtree, pParent, iCell, iHeight+1);
|
|
}
|
|
rc2 = nodeRelease(pRtree, pParent);
|
|
if( rc==SQLITE_OK ){
|
|
rc = rc2;
|
|
}
|
|
if( rc!=SQLITE_OK ){
|
|
return rc;
|
|
}
|
|
|
|
/* Remove the xxx_node entry. */
|
|
sqlite3_bind_int64(pRtree->pDeleteNode, 1, pNode->iNode);
|
|
sqlite3_step(pRtree->pDeleteNode);
|
|
if( SQLITE_OK!=(rc = sqlite3_reset(pRtree->pDeleteNode)) ){
|
|
return rc;
|
|
}
|
|
|
|
/* Remove the xxx_parent entry. */
|
|
sqlite3_bind_int64(pRtree->pDeleteParent, 1, pNode->iNode);
|
|
sqlite3_step(pRtree->pDeleteParent);
|
|
if( SQLITE_OK!=(rc = sqlite3_reset(pRtree->pDeleteParent)) ){
|
|
return rc;
|
|
}
|
|
|
|
/* Remove the node from the in-memory hash table and link it into
|
|
** the Rtree.pDeleted list. Its contents will be re-inserted later on.
|
|
*/
|
|
nodeHashDelete(pRtree, pNode);
|
|
pNode->iNode = iHeight;
|
|
pNode->pNext = pRtree->pDeleted;
|
|
pNode->nRef++;
|
|
pRtree->pDeleted = pNode;
|
|
|
|
return SQLITE_OK;
|
|
}
|
|
|
|
static int fixBoundingBox(Rtree *pRtree, RtreeNode *pNode){
|
|
RtreeNode *pParent = pNode->pParent;
|
|
int rc = SQLITE_OK;
|
|
if( pParent ){
|
|
int ii;
|
|
int nCell = NCELL(pNode);
|
|
RtreeCell box; /* Bounding box for pNode */
|
|
nodeGetCell(pRtree, pNode, 0, &box);
|
|
for(ii=1; ii<nCell; ii++){
|
|
RtreeCell cell;
|
|
nodeGetCell(pRtree, pNode, ii, &cell);
|
|
cellUnion(pRtree, &box, &cell);
|
|
}
|
|
box.iRowid = pNode->iNode;
|
|
rc = nodeParentIndex(pRtree, pNode, &ii);
|
|
if( rc==SQLITE_OK ){
|
|
nodeOverwriteCell(pRtree, pParent, &box, ii);
|
|
rc = fixBoundingBox(pRtree, pParent);
|
|
}
|
|
}
|
|
return rc;
|
|
}
|
|
|
|
/*
|
|
** Delete the cell at index iCell of node pNode. After removing the
|
|
** cell, adjust the r-tree data structure if required.
|
|
*/
|
|
static int deleteCell(Rtree *pRtree, RtreeNode *pNode, int iCell, int iHeight){
|
|
RtreeNode *pParent;
|
|
int rc;
|
|
|
|
if( SQLITE_OK!=(rc = fixLeafParent(pRtree, pNode)) ){
|
|
return rc;
|
|
}
|
|
|
|
/* Remove the cell from the node. This call just moves bytes around
|
|
** the in-memory node image, so it cannot fail.
|
|
*/
|
|
nodeDeleteCell(pRtree, pNode, iCell);
|
|
|
|
/* If the node is not the tree root and now has less than the minimum
|
|
** number of cells, remove it from the tree. Otherwise, update the
|
|
** cell in the parent node so that it tightly contains the updated
|
|
** node.
|
|
*/
|
|
pParent = pNode->pParent;
|
|
assert( pParent || pNode->iNode==1 );
|
|
if( pParent ){
|
|
if( NCELL(pNode)<RTREE_MINCELLS(pRtree) ){
|
|
rc = removeNode(pRtree, pNode, iHeight);
|
|
}else{
|
|
rc = fixBoundingBox(pRtree, pNode);
|
|
}
|
|
}
|
|
|
|
return rc;
|
|
}
|
|
|
|
static int Reinsert(
|
|
Rtree *pRtree,
|
|
RtreeNode *pNode,
|
|
RtreeCell *pCell,
|
|
int iHeight
|
|
){
|
|
int *aOrder;
|
|
int *aSpare;
|
|
RtreeCell *aCell;
|
|
RtreeDValue *aDistance;
|
|
int nCell;
|
|
RtreeDValue aCenterCoord[RTREE_MAX_DIMENSIONS];
|
|
int iDim;
|
|
int ii;
|
|
int rc = SQLITE_OK;
|
|
int n;
|
|
|
|
memset(aCenterCoord, 0, sizeof(RtreeDValue)*RTREE_MAX_DIMENSIONS);
|
|
|
|
nCell = NCELL(pNode)+1;
|
|
n = (nCell+1)&(~1);
|
|
|
|
/* Allocate the buffers used by this operation. The allocation is
|
|
** relinquished before this function returns.
|
|
*/
|
|
aCell = (RtreeCell *)sqlite3_malloc(n * (
|
|
sizeof(RtreeCell) + /* aCell array */
|
|
sizeof(int) + /* aOrder array */
|
|
sizeof(int) + /* aSpare array */
|
|
sizeof(RtreeDValue) /* aDistance array */
|
|
));
|
|
if( !aCell ){
|
|
return SQLITE_NOMEM;
|
|
}
|
|
aOrder = (int *)&aCell[n];
|
|
aSpare = (int *)&aOrder[n];
|
|
aDistance = (RtreeDValue *)&aSpare[n];
|
|
|
|
for(ii=0; ii<nCell; ii++){
|
|
if( ii==(nCell-1) ){
|
|
memcpy(&aCell[ii], pCell, sizeof(RtreeCell));
|
|
}else{
|
|
nodeGetCell(pRtree, pNode, ii, &aCell[ii]);
|
|
}
|
|
aOrder[ii] = ii;
|
|
for(iDim=0; iDim<pRtree->nDim; iDim++){
|
|
aCenterCoord[iDim] += DCOORD(aCell[ii].aCoord[iDim*2]);
|
|
aCenterCoord[iDim] += DCOORD(aCell[ii].aCoord[iDim*2+1]);
|
|
}
|
|
}
|
|
for(iDim=0; iDim<pRtree->nDim; iDim++){
|
|
aCenterCoord[iDim] = (aCenterCoord[iDim]/(nCell*(RtreeDValue)2));
|
|
}
|
|
|
|
for(ii=0; ii<nCell; ii++){
|
|
aDistance[ii] = 0.0;
|
|
for(iDim=0; iDim<pRtree->nDim; iDim++){
|
|
RtreeDValue coord = (DCOORD(aCell[ii].aCoord[iDim*2+1]) -
|
|
DCOORD(aCell[ii].aCoord[iDim*2]));
|
|
aDistance[ii] += (coord-aCenterCoord[iDim])*(coord-aCenterCoord[iDim]);
|
|
}
|
|
}
|
|
|
|
SortByDistance(aOrder, nCell, aDistance, aSpare);
|
|
nodeZero(pRtree, pNode);
|
|
|
|
for(ii=0; rc==SQLITE_OK && ii<(nCell-(RTREE_MINCELLS(pRtree)+1)); ii++){
|
|
RtreeCell *p = &aCell[aOrder[ii]];
|
|
nodeInsertCell(pRtree, pNode, p);
|
|
if( p->iRowid==pCell->iRowid ){
|
|
if( iHeight==0 ){
|
|
rc = rowidWrite(pRtree, p->iRowid, pNode->iNode);
|
|
}else{
|
|
rc = parentWrite(pRtree, p->iRowid, pNode->iNode);
|
|
}
|
|
}
|
|
}
|
|
if( rc==SQLITE_OK ){
|
|
rc = fixBoundingBox(pRtree, pNode);
|
|
}
|
|
for(; rc==SQLITE_OK && ii<nCell; ii++){
|
|
/* Find a node to store this cell in. pNode->iNode currently contains
|
|
** the height of the sub-tree headed by the cell.
|
|
*/
|
|
RtreeNode *pInsert;
|
|
RtreeCell *p = &aCell[aOrder[ii]];
|
|
rc = ChooseLeaf(pRtree, p, iHeight, &pInsert);
|
|
if( rc==SQLITE_OK ){
|
|
int rc2;
|
|
rc = rtreeInsertCell(pRtree, pInsert, p, iHeight);
|
|
rc2 = nodeRelease(pRtree, pInsert);
|
|
if( rc==SQLITE_OK ){
|
|
rc = rc2;
|
|
}
|
|
}
|
|
}
|
|
|
|
sqlite3_free(aCell);
|
|
return rc;
|
|
}
|
|
|
|
/*
|
|
** Insert cell pCell into node pNode. Node pNode is the head of a
|
|
** subtree iHeight high (leaf nodes have iHeight==0).
|
|
*/
|
|
static int rtreeInsertCell(
|
|
Rtree *pRtree,
|
|
RtreeNode *pNode,
|
|
RtreeCell *pCell,
|
|
int iHeight
|
|
){
|
|
int rc = SQLITE_OK;
|
|
if( iHeight>0 ){
|
|
RtreeNode *pChild = nodeHashLookup(pRtree, pCell->iRowid);
|
|
if( pChild ){
|
|
nodeRelease(pRtree, pChild->pParent);
|
|
nodeReference(pNode);
|
|
pChild->pParent = pNode;
|
|
}
|
|
}
|
|
if( nodeInsertCell(pRtree, pNode, pCell) ){
|
|
#if VARIANT_RSTARTREE_REINSERT
|
|
if( iHeight<=pRtree->iReinsertHeight || pNode->iNode==1){
|
|
rc = SplitNode(pRtree, pNode, pCell, iHeight);
|
|
}else{
|
|
pRtree->iReinsertHeight = iHeight;
|
|
rc = Reinsert(pRtree, pNode, pCell, iHeight);
|
|
}
|
|
#else
|
|
rc = SplitNode(pRtree, pNode, pCell, iHeight);
|
|
#endif
|
|
}else{
|
|
rc = AdjustTree(pRtree, pNode, pCell);
|
|
if( rc==SQLITE_OK ){
|
|
if( iHeight==0 ){
|
|
rc = rowidWrite(pRtree, pCell->iRowid, pNode->iNode);
|
|
}else{
|
|
rc = parentWrite(pRtree, pCell->iRowid, pNode->iNode);
|
|
}
|
|
}
|
|
}
|
|
return rc;
|
|
}
|
|
|
|
static int reinsertNodeContent(Rtree *pRtree, RtreeNode *pNode){
|
|
int ii;
|
|
int rc = SQLITE_OK;
|
|
int nCell = NCELL(pNode);
|
|
|
|
for(ii=0; rc==SQLITE_OK && ii<nCell; ii++){
|
|
RtreeNode *pInsert;
|
|
RtreeCell cell;
|
|
nodeGetCell(pRtree, pNode, ii, &cell);
|
|
|
|
/* Find a node to store this cell in. pNode->iNode currently contains
|
|
** the height of the sub-tree headed by the cell.
|
|
*/
|
|
rc = ChooseLeaf(pRtree, &cell, (int)pNode->iNode, &pInsert);
|
|
if( rc==SQLITE_OK ){
|
|
int rc2;
|
|
rc = rtreeInsertCell(pRtree, pInsert, &cell, (int)pNode->iNode);
|
|
rc2 = nodeRelease(pRtree, pInsert);
|
|
if( rc==SQLITE_OK ){
|
|
rc = rc2;
|
|
}
|
|
}
|
|
}
|
|
return rc;
|
|
}
|
|
|
|
/*
|
|
** Select a currently unused rowid for a new r-tree record.
|
|
*/
|
|
static int newRowid(Rtree *pRtree, i64 *piRowid){
|
|
int rc;
|
|
sqlite3_bind_null(pRtree->pWriteRowid, 1);
|
|
sqlite3_bind_null(pRtree->pWriteRowid, 2);
|
|
sqlite3_step(pRtree->pWriteRowid);
|
|
rc = sqlite3_reset(pRtree->pWriteRowid);
|
|
*piRowid = sqlite3_last_insert_rowid(pRtree->db);
|
|
return rc;
|
|
}
|
|
|
|
/*
|
|
** Remove the entry with rowid=iDelete from the r-tree structure.
|
|
*/
|
|
static int rtreeDeleteRowid(Rtree *pRtree, sqlite3_int64 iDelete){
|
|
int rc; /* Return code */
|
|
RtreeNode *pLeaf = 0; /* Leaf node containing record iDelete */
|
|
int iCell; /* Index of iDelete cell in pLeaf */
|
|
RtreeNode *pRoot; /* Root node of rtree structure */
|
|
|
|
|
|
/* Obtain a reference to the root node to initialize Rtree.iDepth */
|
|
rc = nodeAcquire(pRtree, 1, 0, &pRoot);
|
|
|
|
/* Obtain a reference to the leaf node that contains the entry
|
|
** about to be deleted.
|
|
*/
|
|
if( rc==SQLITE_OK ){
|
|
rc = findLeafNode(pRtree, iDelete, &pLeaf);
|
|
}
|
|
|
|
/* Delete the cell in question from the leaf node. */
|
|
if( rc==SQLITE_OK ){
|
|
int rc2;
|
|
rc = nodeRowidIndex(pRtree, pLeaf, iDelete, &iCell);
|
|
if( rc==SQLITE_OK ){
|
|
rc = deleteCell(pRtree, pLeaf, iCell, 0);
|
|
}
|
|
rc2 = nodeRelease(pRtree, pLeaf);
|
|
if( rc==SQLITE_OK ){
|
|
rc = rc2;
|
|
}
|
|
}
|
|
|
|
/* Delete the corresponding entry in the <rtree>_rowid table. */
|
|
if( rc==SQLITE_OK ){
|
|
sqlite3_bind_int64(pRtree->pDeleteRowid, 1, iDelete);
|
|
sqlite3_step(pRtree->pDeleteRowid);
|
|
rc = sqlite3_reset(pRtree->pDeleteRowid);
|
|
}
|
|
|
|
/* Check if the root node now has exactly one child. If so, remove
|
|
** it, schedule the contents of the child for reinsertion and
|
|
** reduce the tree height by one.
|
|
**
|
|
** This is equivalent to copying the contents of the child into
|
|
** the root node (the operation that Gutman's paper says to perform
|
|
** in this scenario).
|
|
*/
|
|
if( rc==SQLITE_OK && pRtree->iDepth>0 && NCELL(pRoot)==1 ){
|
|
int rc2;
|
|
RtreeNode *pChild;
|
|
i64 iChild = nodeGetRowid(pRtree, pRoot, 0);
|
|
rc = nodeAcquire(pRtree, iChild, pRoot, &pChild);
|
|
if( rc==SQLITE_OK ){
|
|
rc = removeNode(pRtree, pChild, pRtree->iDepth-1);
|
|
}
|
|
rc2 = nodeRelease(pRtree, pChild);
|
|
if( rc==SQLITE_OK ) rc = rc2;
|
|
if( rc==SQLITE_OK ){
|
|
pRtree->iDepth--;
|
|
writeInt16(pRoot->zData, pRtree->iDepth);
|
|
pRoot->isDirty = 1;
|
|
}
|
|
}
|
|
|
|
/* Re-insert the contents of any underfull nodes removed from the tree. */
|
|
for(pLeaf=pRtree->pDeleted; pLeaf; pLeaf=pRtree->pDeleted){
|
|
if( rc==SQLITE_OK ){
|
|
rc = reinsertNodeContent(pRtree, pLeaf);
|
|
}
|
|
pRtree->pDeleted = pLeaf->pNext;
|
|
sqlite3_free(pLeaf);
|
|
}
|
|
|
|
/* Release the reference to the root node. */
|
|
if( rc==SQLITE_OK ){
|
|
rc = nodeRelease(pRtree, pRoot);
|
|
}else{
|
|
nodeRelease(pRtree, pRoot);
|
|
}
|
|
|
|
return rc;
|
|
}
|
|
|
|
/*
|
|
** Rounding constants for float->double conversion.
|
|
*/
|
|
#define RNDTOWARDS (1.0 - 1.0/8388608.0) /* Round towards zero */
|
|
#define RNDAWAY (1.0 + 1.0/8388608.0) /* Round away from zero */
|
|
|
|
#if !defined(SQLITE_RTREE_INT_ONLY)
|
|
/*
|
|
** Convert an sqlite3_value into an RtreeValue (presumably a float)
|
|
** while taking care to round toward negative or positive, respectively.
|
|
*/
|
|
static RtreeValue rtreeValueDown(sqlite3_value *v){
|
|
double d = sqlite3_value_double(v);
|
|
float f = (float)d;
|
|
if( f>d ){
|
|
f = (float)(d*(d<0 ? RNDAWAY : RNDTOWARDS));
|
|
}
|
|
return f;
|
|
}
|
|
static RtreeValue rtreeValueUp(sqlite3_value *v){
|
|
double d = sqlite3_value_double(v);
|
|
float f = (float)d;
|
|
if( f<d ){
|
|
f = (float)(d*(d<0 ? RNDTOWARDS : RNDAWAY));
|
|
}
|
|
return f;
|
|
}
|
|
#endif /* !defined(SQLITE_RTREE_INT_ONLY) */
|
|
|
|
|
|
/*
|
|
** The xUpdate method for rtree module virtual tables.
|
|
*/
|
|
static int rtreeUpdate(
|
|
sqlite3_vtab *pVtab,
|
|
int nData,
|
|
sqlite3_value **azData,
|
|
sqlite_int64 *pRowid
|
|
){
|
|
Rtree *pRtree = (Rtree *)pVtab;
|
|
int rc = SQLITE_OK;
|
|
RtreeCell cell; /* New cell to insert if nData>1 */
|
|
int bHaveRowid = 0; /* Set to 1 after new rowid is determined */
|
|
|
|
rtreeReference(pRtree);
|
|
assert(nData>=1);
|
|
|
|
/* Constraint handling. A write operation on an r-tree table may return
|
|
** SQLITE_CONSTRAINT for two reasons:
|
|
**
|
|
** 1. A duplicate rowid value, or
|
|
** 2. The supplied data violates the "x2>=x1" constraint.
|
|
**
|
|
** In the first case, if the conflict-handling mode is REPLACE, then
|
|
** the conflicting row can be removed before proceeding. In the second
|
|
** case, SQLITE_CONSTRAINT must be returned regardless of the
|
|
** conflict-handling mode specified by the user.
|
|
*/
|
|
if( nData>1 ){
|
|
int ii;
|
|
|
|
/* Populate the cell.aCoord[] array. The first coordinate is azData[3]. */
|
|
assert( nData==(pRtree->nDim*2 + 3) );
|
|
#ifndef SQLITE_RTREE_INT_ONLY
|
|
if( pRtree->eCoordType==RTREE_COORD_REAL32 ){
|
|
for(ii=0; ii<(pRtree->nDim*2); ii+=2){
|
|
cell.aCoord[ii].f = rtreeValueDown(azData[ii+3]);
|
|
cell.aCoord[ii+1].f = rtreeValueUp(azData[ii+4]);
|
|
if( cell.aCoord[ii].f>cell.aCoord[ii+1].f ){
|
|
rc = SQLITE_CONSTRAINT;
|
|
goto constraint;
|
|
}
|
|
}
|
|
}else
|
|
#endif
|
|
{
|
|
for(ii=0; ii<(pRtree->nDim*2); ii+=2){
|
|
cell.aCoord[ii].i = sqlite3_value_int(azData[ii+3]);
|
|
cell.aCoord[ii+1].i = sqlite3_value_int(azData[ii+4]);
|
|
if( cell.aCoord[ii].i>cell.aCoord[ii+1].i ){
|
|
rc = SQLITE_CONSTRAINT;
|
|
goto constraint;
|
|
}
|
|
}
|
|
}
|
|
|
|
/* If a rowid value was supplied, check if it is already present in
|
|
** the table. If so, the constraint has failed. */
|
|
if( sqlite3_value_type(azData[2])!=SQLITE_NULL ){
|
|
cell.iRowid = sqlite3_value_int64(azData[2]);
|
|
if( sqlite3_value_type(azData[0])==SQLITE_NULL
|
|
|| sqlite3_value_int64(azData[0])!=cell.iRowid
|
|
){
|
|
int steprc;
|
|
sqlite3_bind_int64(pRtree->pReadRowid, 1, cell.iRowid);
|
|
steprc = sqlite3_step(pRtree->pReadRowid);
|
|
rc = sqlite3_reset(pRtree->pReadRowid);
|
|
if( SQLITE_ROW==steprc ){
|
|
if( sqlite3_vtab_on_conflict(pRtree->db)==SQLITE_REPLACE ){
|
|
rc = rtreeDeleteRowid(pRtree, cell.iRowid);
|
|
}else{
|
|
rc = SQLITE_CONSTRAINT;
|
|
goto constraint;
|
|
}
|
|
}
|
|
}
|
|
bHaveRowid = 1;
|
|
}
|
|
}
|
|
|
|
/* If azData[0] is not an SQL NULL value, it is the rowid of a
|
|
** record to delete from the r-tree table. The following block does
|
|
** just that.
|
|
*/
|
|
if( sqlite3_value_type(azData[0])!=SQLITE_NULL ){
|
|
rc = rtreeDeleteRowid(pRtree, sqlite3_value_int64(azData[0]));
|
|
}
|
|
|
|
/* If the azData[] array contains more than one element, elements
|
|
** (azData[2]..azData[argc-1]) contain a new record to insert into
|
|
** the r-tree structure.
|
|
*/
|
|
if( rc==SQLITE_OK && nData>1 ){
|
|
/* Insert the new record into the r-tree */
|
|
RtreeNode *pLeaf = 0;
|
|
|
|
/* Figure out the rowid of the new row. */
|
|
if( bHaveRowid==0 ){
|
|
rc = newRowid(pRtree, &cell.iRowid);
|
|
}
|
|
*pRowid = cell.iRowid;
|
|
|
|
if( rc==SQLITE_OK ){
|
|
rc = ChooseLeaf(pRtree, &cell, 0, &pLeaf);
|
|
}
|
|
if( rc==SQLITE_OK ){
|
|
int rc2;
|
|
pRtree->iReinsertHeight = -1;
|
|
rc = rtreeInsertCell(pRtree, pLeaf, &cell, 0);
|
|
rc2 = nodeRelease(pRtree, pLeaf);
|
|
if( rc==SQLITE_OK ){
|
|
rc = rc2;
|
|
}
|
|
}
|
|
}
|
|
|
|
constraint:
|
|
rtreeRelease(pRtree);
|
|
return rc;
|
|
}
|
|
|
|
/*
|
|
** The xRename method for rtree module virtual tables.
|
|
*/
|
|
static int rtreeRename(sqlite3_vtab *pVtab, const char *zNewName){
|
|
Rtree *pRtree = (Rtree *)pVtab;
|
|
int rc = SQLITE_NOMEM;
|
|
char *zSql = sqlite3_mprintf(
|
|
"ALTER TABLE %Q.'%q_node' RENAME TO \"%w_node\";"
|
|
"ALTER TABLE %Q.'%q_parent' RENAME TO \"%w_parent\";"
|
|
"ALTER TABLE %Q.'%q_rowid' RENAME TO \"%w_rowid\";"
|
|
, pRtree->zDb, pRtree->zName, zNewName
|
|
, pRtree->zDb, pRtree->zName, zNewName
|
|
, pRtree->zDb, pRtree->zName, zNewName
|
|
);
|
|
if( zSql ){
|
|
rc = sqlite3_exec(pRtree->db, zSql, 0, 0, 0);
|
|
sqlite3_free(zSql);
|
|
}
|
|
return rc;
|
|
}
|
|
|
|
static sqlite3_module rtreeModule = {
|
|
0, /* iVersion */
|
|
rtreeCreate, /* xCreate - create a table */
|
|
rtreeConnect, /* xConnect - connect to an existing table */
|
|
rtreeBestIndex, /* xBestIndex - Determine search strategy */
|
|
rtreeDisconnect, /* xDisconnect - Disconnect from a table */
|
|
rtreeDestroy, /* xDestroy - Drop a table */
|
|
rtreeOpen, /* xOpen - open a cursor */
|
|
rtreeClose, /* xClose - close a cursor */
|
|
rtreeFilter, /* xFilter - configure scan constraints */
|
|
rtreeNext, /* xNext - advance a cursor */
|
|
rtreeEof, /* xEof */
|
|
rtreeColumn, /* xColumn - read data */
|
|
rtreeRowid, /* xRowid - read data */
|
|
rtreeUpdate, /* xUpdate - write data */
|
|
0, /* xBegin - begin transaction */
|
|
0, /* xSync - sync transaction */
|
|
0, /* xCommit - commit transaction */
|
|
0, /* xRollback - rollback transaction */
|
|
0, /* xFindFunction - function overloading */
|
|
rtreeRename, /* xRename - rename the table */
|
|
0, /* xSavepoint */
|
|
0, /* xRelease */
|
|
0 /* xRollbackTo */
|
|
};
|
|
|
|
static int rtreeSqlInit(
|
|
Rtree *pRtree,
|
|
sqlite3 *db,
|
|
const char *zDb,
|
|
const char *zPrefix,
|
|
int isCreate
|
|
){
|
|
int rc = SQLITE_OK;
|
|
|
|
#define N_STATEMENT 9
|
|
static const char *azSql[N_STATEMENT] = {
|
|
/* Read and write the xxx_node table */
|
|
"SELECT data FROM '%q'.'%q_node' WHERE nodeno = :1",
|
|
"INSERT OR REPLACE INTO '%q'.'%q_node' VALUES(:1, :2)",
|
|
"DELETE FROM '%q'.'%q_node' WHERE nodeno = :1",
|
|
|
|
/* Read and write the xxx_rowid table */
|
|
"SELECT nodeno FROM '%q'.'%q_rowid' WHERE rowid = :1",
|
|
"INSERT OR REPLACE INTO '%q'.'%q_rowid' VALUES(:1, :2)",
|
|
"DELETE FROM '%q'.'%q_rowid' WHERE rowid = :1",
|
|
|
|
/* Read and write the xxx_parent table */
|
|
"SELECT parentnode FROM '%q'.'%q_parent' WHERE nodeno = :1",
|
|
"INSERT OR REPLACE INTO '%q'.'%q_parent' VALUES(:1, :2)",
|
|
"DELETE FROM '%q'.'%q_parent' WHERE nodeno = :1"
|
|
};
|
|
sqlite3_stmt **appStmt[N_STATEMENT];
|
|
int i;
|
|
|
|
pRtree->db = db;
|
|
|
|
if( isCreate ){
|
|
char *zCreate = sqlite3_mprintf(
|
|
"CREATE TABLE \"%w\".\"%w_node\"(nodeno INTEGER PRIMARY KEY, data BLOB);"
|
|
"CREATE TABLE \"%w\".\"%w_rowid\"(rowid INTEGER PRIMARY KEY, nodeno INTEGER);"
|
|
"CREATE TABLE \"%w\".\"%w_parent\"(nodeno INTEGER PRIMARY KEY, parentnode INTEGER);"
|
|
"INSERT INTO '%q'.'%q_node' VALUES(1, zeroblob(%d))",
|
|
zDb, zPrefix, zDb, zPrefix, zDb, zPrefix, zDb, zPrefix, pRtree->iNodeSize
|
|
);
|
|
if( !zCreate ){
|
|
return SQLITE_NOMEM;
|
|
}
|
|
rc = sqlite3_exec(db, zCreate, 0, 0, 0);
|
|
sqlite3_free(zCreate);
|
|
if( rc!=SQLITE_OK ){
|
|
return rc;
|
|
}
|
|
}
|
|
|
|
appStmt[0] = &pRtree->pReadNode;
|
|
appStmt[1] = &pRtree->pWriteNode;
|
|
appStmt[2] = &pRtree->pDeleteNode;
|
|
appStmt[3] = &pRtree->pReadRowid;
|
|
appStmt[4] = &pRtree->pWriteRowid;
|
|
appStmt[5] = &pRtree->pDeleteRowid;
|
|
appStmt[6] = &pRtree->pReadParent;
|
|
appStmt[7] = &pRtree->pWriteParent;
|
|
appStmt[8] = &pRtree->pDeleteParent;
|
|
|
|
for(i=0; i<N_STATEMENT && rc==SQLITE_OK; i++){
|
|
char *zSql = sqlite3_mprintf(azSql[i], zDb, zPrefix);
|
|
if( zSql ){
|
|
rc = sqlite3_prepare_v2(db, zSql, -1, appStmt[i], 0);
|
|
}else{
|
|
rc = SQLITE_NOMEM;
|
|
}
|
|
sqlite3_free(zSql);
|
|
}
|
|
|
|
return rc;
|
|
}
|
|
|
|
/*
|
|
** The second argument to this function contains the text of an SQL statement
|
|
** that returns a single integer value. The statement is compiled and executed
|
|
** using database connection db. If successful, the integer value returned
|
|
** is written to *piVal and SQLITE_OK returned. Otherwise, an SQLite error
|
|
** code is returned and the value of *piVal after returning is not defined.
|
|
*/
|
|
static int getIntFromStmt(sqlite3 *db, const char *zSql, int *piVal){
|
|
int rc = SQLITE_NOMEM;
|
|
if( zSql ){
|
|
sqlite3_stmt *pStmt = 0;
|
|
rc = sqlite3_prepare_v2(db, zSql, -1, &pStmt, 0);
|
|
if( rc==SQLITE_OK ){
|
|
if( SQLITE_ROW==sqlite3_step(pStmt) ){
|
|
*piVal = sqlite3_column_int(pStmt, 0);
|
|
}
|
|
rc = sqlite3_finalize(pStmt);
|
|
}
|
|
}
|
|
return rc;
|
|
}
|
|
|
|
/*
|
|
** This function is called from within the xConnect() or xCreate() method to
|
|
** determine the node-size used by the rtree table being created or connected
|
|
** to. If successful, pRtree->iNodeSize is populated and SQLITE_OK returned.
|
|
** Otherwise, an SQLite error code is returned.
|
|
**
|
|
** If this function is being called as part of an xConnect(), then the rtree
|
|
** table already exists. In this case the node-size is determined by inspecting
|
|
** the root node of the tree.
|
|
**
|
|
** Otherwise, for an xCreate(), use 64 bytes less than the database page-size.
|
|
** This ensures that each node is stored on a single database page. If the
|
|
** database page-size is so large that more than RTREE_MAXCELLS entries
|
|
** would fit in a single node, use a smaller node-size.
|
|
*/
|
|
static int getNodeSize(
|
|
sqlite3 *db, /* Database handle */
|
|
Rtree *pRtree, /* Rtree handle */
|
|
int isCreate, /* True for xCreate, false for xConnect */
|
|
char **pzErr /* OUT: Error message, if any */
|
|
){
|
|
int rc;
|
|
char *zSql;
|
|
if( isCreate ){
|
|
int iPageSize = 0;
|
|
zSql = sqlite3_mprintf("PRAGMA %Q.page_size", pRtree->zDb);
|
|
rc = getIntFromStmt(db, zSql, &iPageSize);
|
|
if( rc==SQLITE_OK ){
|
|
pRtree->iNodeSize = iPageSize-64;
|
|
if( (4+pRtree->nBytesPerCell*RTREE_MAXCELLS)<pRtree->iNodeSize ){
|
|
pRtree->iNodeSize = 4+pRtree->nBytesPerCell*RTREE_MAXCELLS;
|
|
}
|
|
}else{
|
|
*pzErr = sqlite3_mprintf("%s", sqlite3_errmsg(db));
|
|
}
|
|
}else{
|
|
zSql = sqlite3_mprintf(
|
|
"SELECT length(data) FROM '%q'.'%q_node' WHERE nodeno = 1",
|
|
pRtree->zDb, pRtree->zName
|
|
);
|
|
rc = getIntFromStmt(db, zSql, &pRtree->iNodeSize);
|
|
if( rc!=SQLITE_OK ){
|
|
*pzErr = sqlite3_mprintf("%s", sqlite3_errmsg(db));
|
|
}
|
|
}
|
|
|
|
sqlite3_free(zSql);
|
|
return rc;
|
|
}
|
|
|
|
/*
|
|
** This function is the implementation of both the xConnect and xCreate
|
|
** methods of the r-tree virtual table.
|
|
**
|
|
** argv[0] -> module name
|
|
** argv[1] -> database name
|
|
** argv[2] -> table name
|
|
** argv[...] -> column names...
|
|
*/
|
|
static int rtreeInit(
|
|
sqlite3 *db, /* Database connection */
|
|
void *pAux, /* One of the RTREE_COORD_* constants */
|
|
int argc, const char *const*argv, /* Parameters to CREATE TABLE statement */
|
|
sqlite3_vtab **ppVtab, /* OUT: New virtual table */
|
|
char **pzErr, /* OUT: Error message, if any */
|
|
int isCreate /* True for xCreate, false for xConnect */
|
|
){
|
|
int rc = SQLITE_OK;
|
|
Rtree *pRtree;
|
|
int nDb; /* Length of string argv[1] */
|
|
int nName; /* Length of string argv[2] */
|
|
int eCoordType = (pAux ? RTREE_COORD_INT32 : RTREE_COORD_REAL32);
|
|
|
|
const char *aErrMsg[] = {
|
|
0, /* 0 */
|
|
"Wrong number of columns for an rtree table", /* 1 */
|
|
"Too few columns for an rtree table", /* 2 */
|
|
"Too many columns for an rtree table" /* 3 */
|
|
};
|
|
|
|
int iErr = (argc<6) ? 2 : argc>(RTREE_MAX_DIMENSIONS*2+4) ? 3 : argc%2;
|
|
if( aErrMsg[iErr] ){
|
|
*pzErr = sqlite3_mprintf("%s", aErrMsg[iErr]);
|
|
return SQLITE_ERROR;
|
|
}
|
|
|
|
sqlite3_vtab_config(db, SQLITE_VTAB_CONSTRAINT_SUPPORT, 1);
|
|
|
|
/* Allocate the sqlite3_vtab structure */
|
|
nDb = (int)strlen(argv[1]);
|
|
nName = (int)strlen(argv[2]);
|
|
pRtree = (Rtree *)sqlite3_malloc(sizeof(Rtree)+nDb+nName+2);
|
|
if( !pRtree ){
|
|
return SQLITE_NOMEM;
|
|
}
|
|
memset(pRtree, 0, sizeof(Rtree)+nDb+nName+2);
|
|
pRtree->nBusy = 1;
|
|
pRtree->base.pModule = &rtreeModule;
|
|
pRtree->zDb = (char *)&pRtree[1];
|
|
pRtree->zName = &pRtree->zDb[nDb+1];
|
|
pRtree->nDim = (argc-4)/2;
|
|
pRtree->nBytesPerCell = 8 + pRtree->nDim*4*2;
|
|
pRtree->eCoordType = eCoordType;
|
|
memcpy(pRtree->zDb, argv[1], nDb);
|
|
memcpy(pRtree->zName, argv[2], nName);
|
|
|
|
/* Figure out the node size to use. */
|
|
rc = getNodeSize(db, pRtree, isCreate, pzErr);
|
|
|
|
/* Create/Connect to the underlying relational database schema. If
|
|
** that is successful, call sqlite3_declare_vtab() to configure
|
|
** the r-tree table schema.
|
|
*/
|
|
if( rc==SQLITE_OK ){
|
|
if( (rc = rtreeSqlInit(pRtree, db, argv[1], argv[2], isCreate)) ){
|
|
*pzErr = sqlite3_mprintf("%s", sqlite3_errmsg(db));
|
|
}else{
|
|
char *zSql = sqlite3_mprintf("CREATE TABLE x(%s", argv[3]);
|
|
char *zTmp;
|
|
int ii;
|
|
for(ii=4; zSql && ii<argc; ii++){
|
|
zTmp = zSql;
|
|
zSql = sqlite3_mprintf("%s, %s", zTmp, argv[ii]);
|
|
sqlite3_free(zTmp);
|
|
}
|
|
if( zSql ){
|
|
zTmp = zSql;
|
|
zSql = sqlite3_mprintf("%s);", zTmp);
|
|
sqlite3_free(zTmp);
|
|
}
|
|
if( !zSql ){
|
|
rc = SQLITE_NOMEM;
|
|
}else if( SQLITE_OK!=(rc = sqlite3_declare_vtab(db, zSql)) ){
|
|
*pzErr = sqlite3_mprintf("%s", sqlite3_errmsg(db));
|
|
}
|
|
sqlite3_free(zSql);
|
|
}
|
|
}
|
|
|
|
if( rc==SQLITE_OK ){
|
|
*ppVtab = (sqlite3_vtab *)pRtree;
|
|
}else{
|
|
rtreeRelease(pRtree);
|
|
}
|
|
return rc;
|
|
}
|
|
|
|
|
|
/*
|
|
** Implementation of a scalar function that decodes r-tree nodes to
|
|
** human readable strings. This can be used for debugging and analysis.
|
|
**
|
|
** The scalar function takes two arguments, a blob of data containing
|
|
** an r-tree node, and the number of dimensions the r-tree indexes.
|
|
** For a two-dimensional r-tree structure called "rt", to deserialize
|
|
** all nodes, a statement like:
|
|
**
|
|
** SELECT rtreenode(2, data) FROM rt_node;
|
|
**
|
|
** The human readable string takes the form of a Tcl list with one
|
|
** entry for each cell in the r-tree node. Each entry is itself a
|
|
** list, containing the 8-byte rowid/pageno followed by the
|
|
** <num-dimension>*2 coordinates.
|
|
*/
|
|
static void rtreenode(sqlite3_context *ctx, int nArg, sqlite3_value **apArg){
|
|
char *zText = 0;
|
|
RtreeNode node;
|
|
Rtree tree;
|
|
int ii;
|
|
|
|
UNUSED_PARAMETER(nArg);
|
|
memset(&node, 0, sizeof(RtreeNode));
|
|
memset(&tree, 0, sizeof(Rtree));
|
|
tree.nDim = sqlite3_value_int(apArg[0]);
|
|
tree.nBytesPerCell = 8 + 8 * tree.nDim;
|
|
node.zData = (u8 *)sqlite3_value_blob(apArg[1]);
|
|
|
|
for(ii=0; ii<NCELL(&node); ii++){
|
|
char zCell[512];
|
|
int nCell = 0;
|
|
RtreeCell cell;
|
|
int jj;
|
|
|
|
nodeGetCell(&tree, &node, ii, &cell);
|
|
sqlite3_snprintf(512-nCell,&zCell[nCell],"%lld", cell.iRowid);
|
|
nCell = (int)strlen(zCell);
|
|
for(jj=0; jj<tree.nDim*2; jj++){
|
|
#ifndef SQLITE_RTREE_INT_ONLY
|
|
sqlite3_snprintf(512-nCell,&zCell[nCell], " %f",
|
|
(double)cell.aCoord[jj].f);
|
|
#else
|
|
sqlite3_snprintf(512-nCell,&zCell[nCell], " %d",
|
|
cell.aCoord[jj].i);
|
|
#endif
|
|
nCell = (int)strlen(zCell);
|
|
}
|
|
|
|
if( zText ){
|
|
char *zTextNew = sqlite3_mprintf("%s {%s}", zText, zCell);
|
|
sqlite3_free(zText);
|
|
zText = zTextNew;
|
|
}else{
|
|
zText = sqlite3_mprintf("{%s}", zCell);
|
|
}
|
|
}
|
|
|
|
sqlite3_result_text(ctx, zText, -1, sqlite3_free);
|
|
}
|
|
|
|
static void rtreedepth(sqlite3_context *ctx, int nArg, sqlite3_value **apArg){
|
|
UNUSED_PARAMETER(nArg);
|
|
if( sqlite3_value_type(apArg[0])!=SQLITE_BLOB
|
|
|| sqlite3_value_bytes(apArg[0])<2
|
|
){
|
|
sqlite3_result_error(ctx, "Invalid argument to rtreedepth()", -1);
|
|
}else{
|
|
u8 *zBlob = (u8 *)sqlite3_value_blob(apArg[0]);
|
|
sqlite3_result_int(ctx, readInt16(zBlob));
|
|
}
|
|
}
|
|
|
|
/*
|
|
** Register the r-tree module with database handle db. This creates the
|
|
** virtual table module "rtree" and the debugging/analysis scalar
|
|
** function "rtreenode".
|
|
*/
|
|
int sqlite3RtreeInit(sqlite3 *db){
|
|
const int utf8 = SQLITE_UTF8;
|
|
int rc;
|
|
|
|
rc = sqlite3_create_function(db, "rtreenode", 2, utf8, 0, rtreenode, 0, 0);
|
|
if( rc==SQLITE_OK ){
|
|
rc = sqlite3_create_function(db, "rtreedepth", 1, utf8, 0,rtreedepth, 0, 0);
|
|
}
|
|
if( rc==SQLITE_OK ){
|
|
#ifdef SQLITE_RTREE_INT_ONLY
|
|
void *c = (void *)RTREE_COORD_INT32;
|
|
#else
|
|
void *c = (void *)RTREE_COORD_REAL32;
|
|
#endif
|
|
rc = sqlite3_create_module_v2(db, "rtree", &rtreeModule, c, 0);
|
|
}
|
|
if( rc==SQLITE_OK ){
|
|
void *c = (void *)RTREE_COORD_INT32;
|
|
rc = sqlite3_create_module_v2(db, "rtree_i32", &rtreeModule, c, 0);
|
|
}
|
|
|
|
return rc;
|
|
}
|
|
|
|
/*
|
|
** A version of sqlite3_free() that can be used as a callback. This is used
|
|
** in two places - as the destructor for the blob value returned by the
|
|
** invocation of a geometry function, and as the destructor for the geometry
|
|
** functions themselves.
|
|
*/
|
|
static void doSqlite3Free(void *p){
|
|
sqlite3_free(p);
|
|
}
|
|
|
|
/*
|
|
** Each call to sqlite3_rtree_geometry_callback() creates an ordinary SQLite
|
|
** scalar user function. This C function is the callback used for all such
|
|
** registered SQL functions.
|
|
**
|
|
** The scalar user functions return a blob that is interpreted by r-tree
|
|
** table MATCH operators.
|
|
*/
|
|
static void geomCallback(sqlite3_context *ctx, int nArg, sqlite3_value **aArg){
|
|
RtreeGeomCallback *pGeomCtx = (RtreeGeomCallback *)sqlite3_user_data(ctx);
|
|
RtreeMatchArg *pBlob;
|
|
int nBlob;
|
|
|
|
nBlob = sizeof(RtreeMatchArg) + (nArg-1)*sizeof(RtreeDValue);
|
|
pBlob = (RtreeMatchArg *)sqlite3_malloc(nBlob);
|
|
if( !pBlob ){
|
|
sqlite3_result_error_nomem(ctx);
|
|
}else{
|
|
int i;
|
|
pBlob->magic = RTREE_GEOMETRY_MAGIC;
|
|
pBlob->xGeom = pGeomCtx->xGeom;
|
|
pBlob->pContext = pGeomCtx->pContext;
|
|
pBlob->nParam = nArg;
|
|
for(i=0; i<nArg; i++){
|
|
#ifdef SQLITE_RTREE_INT_ONLY
|
|
pBlob->aParam[i] = sqlite3_value_int64(aArg[i]);
|
|
#else
|
|
pBlob->aParam[i] = sqlite3_value_double(aArg[i]);
|
|
#endif
|
|
}
|
|
sqlite3_result_blob(ctx, pBlob, nBlob, doSqlite3Free);
|
|
}
|
|
}
|
|
|
|
/*
|
|
** Register a new geometry function for use with the r-tree MATCH operator.
|
|
*/
|
|
int sqlite3_rtree_geometry_callback(
|
|
sqlite3 *db,
|
|
const char *zGeom,
|
|
int (*xGeom)(sqlite3_rtree_geometry *, int, RtreeDValue *, int *),
|
|
void *pContext
|
|
){
|
|
RtreeGeomCallback *pGeomCtx; /* Context object for new user-function */
|
|
|
|
/* Allocate and populate the context object. */
|
|
pGeomCtx = (RtreeGeomCallback *)sqlite3_malloc(sizeof(RtreeGeomCallback));
|
|
if( !pGeomCtx ) return SQLITE_NOMEM;
|
|
pGeomCtx->xGeom = xGeom;
|
|
pGeomCtx->pContext = pContext;
|
|
|
|
/* Create the new user-function. Register a destructor function to delete
|
|
** the context object when it is no longer required. */
|
|
return sqlite3_create_function_v2(db, zGeom, -1, SQLITE_ANY,
|
|
(void *)pGeomCtx, geomCallback, 0, 0, doSqlite3Free
|
|
);
|
|
}
|
|
|
|
#if !SQLITE_CORE
|
|
#ifdef _WIN32
|
|
__declspec(dllexport)
|
|
#endif
|
|
int sqlite3_rtree_init(
|
|
sqlite3 *db,
|
|
char **pzErrMsg,
|
|
const sqlite3_api_routines *pApi
|
|
){
|
|
SQLITE_EXTENSION_INIT2(pApi)
|
|
return sqlite3RtreeInit(db);
|
|
}
|
|
#endif
|
|
|
|
#endif
|