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Unified Diff: third_party/sqlite/ext/rtree/rtree.c

Issue 3108030: Move bundled copy of sqlite one level deeper to better separate it... (Closed) Base URL: svn://svn.chromium.org/chrome/trunk/src/
Patch Set: Created 10 years, 4 months ago
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Index: third_party/sqlite/ext/rtree/rtree.c
===================================================================
--- third_party/sqlite/ext/rtree/rtree.c (revision 56608)
+++ third_party/sqlite/ext/rtree/rtree.c (working copy)
@@ -1,2861 +0,0 @@
-/*
-** 2001 September 15
-**
-** The author disclaims copyright to this source code. In place of
-** a legal notice, here is a blessing:
-**
-** May you do good and not evil.
-** May you find forgiveness for yourself and forgive others.
-** May you share freely, never taking more than you give.
-**
-*************************************************************************
-** This file contains code for implementations of the r-tree and r*-tree
-** algorithms packaged as an SQLite virtual table module.
-**
-** $Id: rtree.c,v 1.14 2009/08/06 18:36:47 danielk1977 Exp $
-*/
-
-#if !defined(SQLITE_CORE) || defined(SQLITE_ENABLE_RTREE)
-
-/*
-** This file contains an implementation of a couple of different variants
-** of the r-tree algorithm. See the README file for further details. The
-** same data-structure is used for all, but the algorithms for insert and
-** delete operations vary. The variants used are selected at compile time
-** by defining the following symbols:
-*/
-
-/* Either, both or none of the following may be set to activate
-** r*tree variant algorithms.
-*/
-#define VARIANT_RSTARTREE_CHOOSESUBTREE 0
-#define VARIANT_RSTARTREE_REINSERT 1
-
-/*
-** Exactly one of the following must be set to 1.
-*/
-#define VARIANT_GUTTMAN_QUADRATIC_SPLIT 0
-#define VARIANT_GUTTMAN_LINEAR_SPLIT 0
-#define VARIANT_RSTARTREE_SPLIT 1
-
-#define VARIANT_GUTTMAN_SPLIT \
- (VARIANT_GUTTMAN_LINEAR_SPLIT||VARIANT_GUTTMAN_QUADRATIC_SPLIT)
-
-#if VARIANT_GUTTMAN_QUADRATIC_SPLIT
- #define PickNext QuadraticPickNext
- #define PickSeeds QuadraticPickSeeds
- #define AssignCells splitNodeGuttman
-#endif
-#if VARIANT_GUTTMAN_LINEAR_SPLIT
- #define PickNext LinearPickNext
- #define PickSeeds LinearPickSeeds
- #define AssignCells splitNodeGuttman
-#endif
-#if VARIANT_RSTARTREE_SPLIT
- #define AssignCells splitNodeStartree
-#endif
-
-
-#ifndef SQLITE_CORE
- #include "sqlite3ext.h"
- SQLITE_EXTENSION_INIT1
-#else
- #include "sqlite3.h"
-#endif
-
-#include <string.h>
-#include <assert.h>
-
-#ifndef SQLITE_AMALGAMATION
-typedef sqlite3_int64 i64;
-typedef unsigned char u8;
-typedef unsigned int u32;
-#endif
-
-typedef struct Rtree Rtree;
-typedef struct RtreeCursor RtreeCursor;
-typedef struct RtreeNode RtreeNode;
-typedef struct RtreeCell RtreeCell;
-typedef struct RtreeConstraint RtreeConstraint;
-typedef union RtreeCoord RtreeCoord;
-
-/* The rtree may have between 1 and RTREE_MAX_DIMENSIONS dimensions. */
-#define RTREE_MAX_DIMENSIONS 5
-
-/* Size of hash table Rtree.aHash. This hash table is not expected to
-** ever contain very many entries, so a fixed number of buckets is
-** used.
-*/
-#define HASHSIZE 128
-
-/*
-** An rtree virtual-table object.
-*/
-struct Rtree {
- sqlite3_vtab base;
- sqlite3 *db; /* Host database connection */
- int iNodeSize; /* Size in bytes of each node in the node table */
- int nDim; /* Number of dimensions */
- int nBytesPerCell; /* Bytes consumed per cell */
- int iDepth; /* Current depth of the r-tree structure */
- char *zDb; /* Name of database containing r-tree table */
- char *zName; /* Name of r-tree table */
- RtreeNode *aHash[HASHSIZE]; /* Hash table of in-memory nodes. */
- int nBusy; /* Current number of users of this structure */
-
- /* List of nodes removed during a CondenseTree operation. List is
- ** linked together via the pointer normally used for hash chains -
- ** RtreeNode.pNext. RtreeNode.iNode stores the depth of the sub-tree
- ** headed by the node (leaf nodes have RtreeNode.iNode==0).
- */
- RtreeNode *pDeleted;
- int iReinsertHeight; /* Height of sub-trees Reinsert() has run on */
-
- /* Statements to read/write/delete a record from xxx_node */
- sqlite3_stmt *pReadNode;
- sqlite3_stmt *pWriteNode;
- sqlite3_stmt *pDeleteNode;
-
- /* Statements to read/write/delete a record from xxx_rowid */
- sqlite3_stmt *pReadRowid;
- sqlite3_stmt *pWriteRowid;
- sqlite3_stmt *pDeleteRowid;
-
- /* Statements to read/write/delete a record from xxx_parent */
- sqlite3_stmt *pReadParent;
- sqlite3_stmt *pWriteParent;
- sqlite3_stmt *pDeleteParent;
-
- int eCoordType;
-};
-
-/* Possible values for eCoordType: */
-#define RTREE_COORD_REAL32 0
-#define RTREE_COORD_INT32 1
-
-/*
-** The minimum number of cells allowed for a node is a third of the
-** maximum. In Gutman's notation:
-**
-** m = M/3
-**
-** If an R*-tree "Reinsert" operation is required, the same number of
-** cells are removed from the overfull node and reinserted into the tree.
-*/
-#define RTREE_MINCELLS(p) ((((p)->iNodeSize-4)/(p)->nBytesPerCell)/3)
-#define RTREE_REINSERT(p) RTREE_MINCELLS(p)
-#define RTREE_MAXCELLS 51
-
-/*
-** An rtree cursor object.
-*/
-struct RtreeCursor {
- sqlite3_vtab_cursor base;
- RtreeNode *pNode; /* Node cursor is currently pointing at */
- int iCell; /* Index of current cell in pNode */
- int iStrategy; /* Copy of idxNum search parameter */
- int nConstraint; /* Number of entries in aConstraint */
- RtreeConstraint *aConstraint; /* Search constraints. */
-};
-
-union RtreeCoord {
- float f;
- int i;
-};
-
-/*
-** The argument is an RtreeCoord. Return the value stored within the RtreeCoord
-** formatted as a double. This macro assumes that local variable pRtree points
-** to the Rtree structure associated with the RtreeCoord.
-*/
-#define DCOORD(coord) ( \
- (pRtree->eCoordType==RTREE_COORD_REAL32) ? \
- ((double)coord.f) : \
- ((double)coord.i) \
-)
-
-/*
-** A search constraint.
-*/
-struct RtreeConstraint {
- int iCoord; /* Index of constrained coordinate */
- int op; /* Constraining operation */
- double rValue; /* Constraint value. */
-};
-
-/* Possible values for RtreeConstraint.op */
-#define RTREE_EQ 0x41
-#define RTREE_LE 0x42
-#define RTREE_LT 0x43
-#define RTREE_GE 0x44
-#define RTREE_GT 0x45
-
-/*
-** An rtree structure node.
-**
-** Data format (RtreeNode.zData):
-**
-** 1. If the node is the root node (node 1), then the first 2 bytes
-** of the node contain the tree depth as a big-endian integer.
-** For non-root nodes, the first 2 bytes are left unused.
-**
-** 2. The next 2 bytes contain the number of entries currently
-** stored in the node.
-**
-** 3. The remainder of the node contains the node entries. Each entry
-** consists of a single 8-byte integer followed by an even number
-** of 4-byte coordinates. For leaf nodes the integer is the rowid
-** of a record. For internal nodes it is the node number of a
-** child page.
-*/
-struct RtreeNode {
- RtreeNode *pParent; /* Parent node */
- i64 iNode;
- int nRef;
- int isDirty;
- u8 *zData;
- RtreeNode *pNext; /* Next node in this hash chain */
-};
-#define NCELL(pNode) readInt16(&(pNode)->zData[2])
-
-/*
-** Structure to store a deserialized rtree record.
-*/
-struct RtreeCell {
- i64 iRowid;
- RtreeCoord aCoord[RTREE_MAX_DIMENSIONS*2];
-};
-
-#ifndef MAX
-# define MAX(x,y) ((x) < (y) ? (y) : (x))
-#endif
-#ifndef MIN
-# define MIN(x,y) ((x) > (y) ? (y) : (x))
-#endif
-
-/*
-** Functions to deserialize a 16 bit integer, 32 bit real number and
-** 64 bit integer. The deserialized value is returned.
-*/
-static int readInt16(u8 *p){
- return (p[0]<<8) + p[1];
-}
-static void readCoord(u8 *p, RtreeCoord *pCoord){
- u32 i = (
- (((u32)p[0]) << 24) +
- (((u32)p[1]) << 16) +
- (((u32)p[2]) << 8) +
- (((u32)p[3]) << 0)
- );
- *(u32 *)pCoord = i;
-}
-static i64 readInt64(u8 *p){
- return (
- (((i64)p[0]) << 56) +
- (((i64)p[1]) << 48) +
- (((i64)p[2]) << 40) +
- (((i64)p[3]) << 32) +
- (((i64)p[4]) << 24) +
- (((i64)p[5]) << 16) +
- (((i64)p[6]) << 8) +
- (((i64)p[7]) << 0)
- );
-}
-
-/*
-** Functions to serialize a 16 bit integer, 32 bit real number and
-** 64 bit integer. The value returned is the number of bytes written
-** to the argument buffer (always 2, 4 and 8 respectively).
-*/
-static int writeInt16(u8 *p, int i){
- p[0] = (i>> 8)&0xFF;
- p[1] = (i>> 0)&0xFF;
- return 2;
-}
-static int writeCoord(u8 *p, RtreeCoord *pCoord){
- u32 i;
- assert( sizeof(RtreeCoord)==4 );
- assert( sizeof(u32)==4 );
- i = *(u32 *)pCoord;
- p[0] = (i>>24)&0xFF;
- p[1] = (i>>16)&0xFF;
- p[2] = (i>> 8)&0xFF;
- p[3] = (i>> 0)&0xFF;
- return 4;
-}
-static int writeInt64(u8 *p, i64 i){
- p[0] = (i>>56)&0xFF;
- p[1] = (i>>48)&0xFF;
- p[2] = (i>>40)&0xFF;
- p[3] = (i>>32)&0xFF;
- p[4] = (i>>24)&0xFF;
- p[5] = (i>>16)&0xFF;
- p[6] = (i>> 8)&0xFF;
- p[7] = (i>> 0)&0xFF;
- return 8;
-}
-
-/*
-** Increment the reference count of node p.
-*/
-static void nodeReference(RtreeNode *p){
- if( p ){
- p->nRef++;
- }
-}
-
-/*
-** Clear the content of node p (set all bytes to 0x00).
-*/
-static void nodeZero(Rtree *pRtree, RtreeNode *p){
- if( p ){
- memset(&p->zData[2], 0, pRtree->iNodeSize-2);
- p->isDirty = 1;
- }
-}
-
-/*
-** Given a node number iNode, return the corresponding key to use
-** in the Rtree.aHash table.
-*/
-static int nodeHash(i64 iNode){
- return (
- (iNode>>56) ^ (iNode>>48) ^ (iNode>>40) ^ (iNode>>32) ^
- (iNode>>24) ^ (iNode>>16) ^ (iNode>> 8) ^ (iNode>> 0)
- ) % HASHSIZE;
-}
-
-/*
-** Search the node hash table for node iNode. If found, return a pointer
-** to it. Otherwise, return 0.
-*/
-static RtreeNode *nodeHashLookup(Rtree *pRtree, i64 iNode){
- RtreeNode *p;
- assert( iNode!=0 );
- for(p=pRtree->aHash[nodeHash(iNode)]; p && p->iNode!=iNode; p=p->pNext);
- return p;
-}
-
-/*
-** Add node pNode to the node hash table.
-*/
-static void nodeHashInsert(Rtree *pRtree, RtreeNode *pNode){
- if( pNode ){
- int iHash;
- assert( pNode->pNext==0 );
- iHash = nodeHash(pNode->iNode);
- pNode->pNext = pRtree->aHash[iHash];
- pRtree->aHash[iHash] = pNode;
- }
-}
-
-/*
-** Remove node pNode from the node hash table.
-*/
-static void nodeHashDelete(Rtree *pRtree, RtreeNode *pNode){
- RtreeNode **pp;
- if( pNode->iNode!=0 ){
- pp = &pRtree->aHash[nodeHash(pNode->iNode)];
- for( ; (*pp)!=pNode; pp = &(*pp)->pNext){ assert(*pp); }
- *pp = pNode->pNext;
- pNode->pNext = 0;
- }
-}
-
-/*
-** Allocate and return new r-tree node. Initially, (RtreeNode.iNode==0),
-** indicating that node has not yet been assigned a node number. It is
-** assigned a node number when nodeWrite() is called to write the
-** node contents out to the database.
-*/
-static RtreeNode *nodeNew(Rtree *pRtree, RtreeNode *pParent, int zero){
- RtreeNode *pNode;
- pNode = (RtreeNode *)sqlite3_malloc(sizeof(RtreeNode) + pRtree->iNodeSize);
- if( pNode ){
- memset(pNode, 0, sizeof(RtreeNode) + (zero?pRtree->iNodeSize:0));
- pNode->zData = (u8 *)&pNode[1];
- pNode->nRef = 1;
- pNode->pParent = pParent;
- pNode->isDirty = 1;
- nodeReference(pParent);
- }
- return pNode;
-}
-
-/*
-** Obtain a reference to an r-tree node.
-*/
-static int
-nodeAcquire(
- Rtree *pRtree, /* R-tree structure */
- i64 iNode, /* Node number to load */
- RtreeNode *pParent, /* Either the parent node or NULL */
- RtreeNode **ppNode /* OUT: Acquired node */
-){
- int rc;
- RtreeNode *pNode;
-
- /* Check if the requested node is already in the hash table. If so,
- ** increase its reference count and return it.
- */
- if( (pNode = nodeHashLookup(pRtree, iNode)) ){
- assert( !pParent || !pNode->pParent || pNode->pParent==pParent );
- if( pParent && !pNode->pParent ){
- nodeReference(pParent);
- pNode->pParent = pParent;
- }
- pNode->nRef++;
- *ppNode = pNode;
- return SQLITE_OK;
- }
-
- pNode = (RtreeNode *)sqlite3_malloc(sizeof(RtreeNode) + pRtree->iNodeSize);
- if( !pNode ){
- *ppNode = 0;
- return SQLITE_NOMEM;
- }
- pNode->pParent = pParent;
- pNode->zData = (u8 *)&pNode[1];
- pNode->nRef = 1;
- pNode->iNode = iNode;
- pNode->isDirty = 0;
- pNode->pNext = 0;
-
- 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);
- memcpy(pNode->zData, zBlob, pRtree->iNodeSize);
- nodeReference(pParent);
- }else{
- sqlite3_free(pNode);
- pNode = 0;
- }
-
- *ppNode = pNode;
- rc = sqlite3_reset(pRtree->pReadNode);
-
- if( rc==SQLITE_OK && iNode==1 ){
- pRtree->iDepth = readInt16(pNode->zData);
- }
-
- assert( (rc==SQLITE_OK && pNode) || (pNode==0 && rc!=SQLITE_OK) );
- nodeHashInsert(pRtree, pNode);
-
- 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;
-}
-
-/*
-** Rtree virtual table module xClose method.
-*/
-static int rtreeClose(sqlite3_vtab_cursor *cur){
- Rtree *pRtree = (Rtree *)(cur->pVtab);
- int rc;
- RtreeCursor *pCsr = (RtreeCursor *)cur;
- sqlite3_free(pCsr->aConstraint);
- 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);
-}
-
-/*
-** Cursor pCursor currently points to a cell in a non-leaf page.
-** Return true if the sub-tree headed by the cell is filtered
-** (excluded) by the constraints in the pCursor->aConstraint[]
-** array, or false otherwise.
-*/
-static int testRtreeCell(Rtree *pRtree, RtreeCursor *pCursor){
- RtreeCell cell;
- int ii;
- int bRes = 0;
-
- nodeGetCell(pRtree, pCursor->pNode, pCursor->iCell, &cell);
- for(ii=0; bRes==0 && ii<pCursor->nConstraint; ii++){
- RtreeConstraint *p = &pCursor->aConstraint[ii];
- double cell_min = DCOORD(cell.aCoord[(p->iCoord>>1)*2]);
- double 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
- );
-
- 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;
- }
- }
-
- return bRes;
-}
-
-/*
-** Return true if the cell that cursor pCursor currently points to
-** would be filtered (excluded) by the constraints in the
-** pCursor->aConstraint[] array, or false otherwise.
-**
-** This function assumes that the cell is part of a leaf node.
-*/
-static int testRtreeEntry(Rtree *pRtree, RtreeCursor *pCursor){
- RtreeCell cell;
- int ii;
-
- nodeGetCell(pRtree, pCursor->pNode, pCursor->iCell, &cell);
- for(ii=0; ii<pCursor->nConstraint; ii++){
- RtreeConstraint *p = &pCursor->aConstraint[ii];
- double 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
- );
- 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;
- }
-
- if( !res ) return 1;
- }
-
- return 0;
-}
-
-/*
-** 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 ){
- isEof = testRtreeEntry(pRtree, pCursor);
- }else{
- isEof = testRtreeCell(pRtree, pCursor);
- }
- if( isEof || iHeight==0 ){
- *pEof = isEof;
- return SQLITE_OK;
- }
-
- iRowid = nodeGetRowid(pRtree, pCursor->pNode, pCursor->iCell);
- rc = nodeAcquire(pRtree, iRowid, pCursor->pNode, &pChild);
- if( rc!=SQLITE_OK ){
- return rc;
- }
-
- 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 ){
- return rc;
- }
- }
-
- if( isEof ){
- assert( pCursor->pNode==pChild );
- nodeReference(pSavedNode);
- nodeRelease(pRtree, pChild);
- pCursor->pNode = pSavedNode;
- pCursor->iCell = iSavedCell;
- }
-
- *pEof = isEof;
- return SQLITE_OK;
-}
-
-/*
-** 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 ii;
- for(ii=0; nodeGetRowid(pRtree, pNode, ii)!=iRowid; ii++){
- assert( ii<(NCELL(pNode)-1) );
- }
- return ii;
-}
-
-/*
-** 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){
- RtreeNode *pParent = pNode->pParent;
- if( pParent ){
- return nodeRowidIndex(pRtree, pParent, pNode->iNode);
- }
- return -1;
-}
-
-/*
-** 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;
-
- 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 if( pCsr->pNode ){
- /* 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;
- pCsr->iCell = nodeParentIndex(pRtree, pNode);
- 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);
- if( pRtree->eCoordType==RTREE_COORD_REAL32 ){
- sqlite3_result_double(ctx, c.f);
- }else{
- 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;
-}
-
-
-/*
-** 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);
-
- sqlite3_free(pCsr->aConstraint);
- pCsr->aConstraint = 0;
- 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 && rc==SQLITE_OK ){
- pCsr->iCell = nodeRowidIndex(pRtree, pLeaf, iRowid);
- }
- }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{
- assert( (idxStr==0 && argc==0) || 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';
- p->rValue = sqlite3_value_double(argv[ii]);
- }
- }
- }
-
- 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.
-** 3 Unused Full table scan.
-** ------------------------------------------------
-**
-** If strategy 1 or 3 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')
-** ----------------------
-**
-** 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, cCol;
-
- int iIdx = 0;
- char zIdxStr[RTREE_MAX_DIMENSIONS*8+1];
- memset(zIdxStr, 0, sizeof(zIdxStr));
-
- assert( pIdxInfo->idxStr==0 );
- for(ii=0; ii<pIdxInfo->nConstraint; 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 ){
- u8 op = 0;
- 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;
- }
- if( op ){
- /* Make sure this particular constraint has not been used before.
- ** If it has been used before, ignore it.
- **
- ** A <= or < can be used if there is a prior >= or >.
- ** A >= or > can be used if there is a prior < or <=.
- ** A <= or < is disqualified if there is a prior <=, <, or ==.
- ** A >= or > is disqualified if there is a prior >=, >, or ==.
- ** A == is disqualifed if there is any prior constraint.
- */
- int j, opmsk;
- static const unsigned char compatible[] = { 0, 0, 1, 1, 2, 2 };
- assert( compatible[RTREE_EQ & 7]==0 );
- assert( compatible[RTREE_LT & 7]==1 );
- assert( compatible[RTREE_LE & 7]==1 );
- assert( compatible[RTREE_GT & 7]==2 );
- assert( compatible[RTREE_GE & 7]==2 );
- cCol = p->iColumn - 1 + 'a';
- opmsk = compatible[op & 7];
- for(j=0; j<iIdx; j+=2){
- if( zIdxStr[j+1]==cCol && (compatible[zIdxStr[j] & 7] & opmsk)!=0 ){
- op = 0;
- break;
- }
- }
- }
- if( op ){
- assert( iIdx<sizeof(zIdxStr)-1 );
- zIdxStr[iIdx++] = op;
- zIdxStr[iIdx++] = cCol;
- 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 float cellArea(Rtree *pRtree, RtreeCell *p){
- float area = 1.0;
- 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 float cellMargin(Rtree *pRtree, RtreeCell *p){
- float margin = 0.0;
- 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 float cellGrowth(Rtree *pRtree, RtreeCell *p, RtreeCell *pCell){
- float 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 float cellOverlap(
- Rtree *pRtree,
- RtreeCell *p,
- RtreeCell *aCell,
- int nCell,
- int iExclude
-){
- int ii;
- float overlap = 0.0;
- for(ii=0; ii<nCell; ii++){
- if( ii!=iExclude ){
- int jj;
- float o = 1.0;
- for(jj=0; jj<(pRtree->nDim*2); jj+=2){
- double x1;
- double 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 float cellOverlapEnlargement(
- Rtree *pRtree,
- RtreeCell *p,
- RtreeCell *pInsert,
- RtreeCell *aCell,
- int nCell,
- int iExclude
-){
- float before;
- float 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;
-
- float fMinGrowth;
- float fMinArea;
- float fMinOverlap;
-
- 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++){
- float growth;
- float area;
- float overlap = 0.0;
- 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);
- }
-#endif
- if( (iCell==0)
- || (overlap<fMinOverlap)
- || (overlap==fMinOverlap && growth<fMinGrowth)
- || (overlap==fMinOverlap && growth==fMinGrowth && area<fMinArea)
- ){
- fMinOverlap = overlap;
- 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 void 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 ){
- RtreeCell cell;
- RtreeNode *pParent = p->pParent;
- int iCell = nodeParentIndex(pRtree, p);
-
- nodeGetCell(pRtree, pParent, iCell, &cell);
- if( !cellContains(pRtree, &cell, pCell) ){
- cellUnion(pRtree, &cell, pCell);
- nodeOverwriteCell(pRtree, pParent, &cell, iCell);
- }
-
- p = pParent;
- }
-}
-
-/*
-** 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;
- float maxNormalInnerWidth = 0.0;
-
- /* 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++){
- float x1 = aCell[0].aCoord[i*2];
- float x2 = aCell[0].aCoord[i*2+1];
- float x3 = x1;
- float x4 = x2;
- int jj;
-
- int iCellLeft = 0;
- int iCellRight = 0;
-
- for(jj=1; jj<nCell; jj++){
- float left = aCell[jj].aCoord[i*2];
- float right = 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 ){
- float 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;
- float fDiff;
- int ii;
- for(ii=0; ii<nCell; ii++){
- if( aiUsed[ii]==0 ){
- float left = cellGrowth(pRtree, pLeftBox, &aCell[ii]);
- float right = cellGrowth(pRtree, pLeftBox, &aCell[ii]);
- float 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;
- float fWaste = 0.0;
-
- for(ii=0; ii<nCell; ii++){
- for(jj=ii+1; jj<nCell; jj++){
- float right = cellArea(pRtree, &aCell[jj]);
- float growth = cellGrowth(pRtree, &aCell[ii], &aCell[jj]);
- float 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,
- float *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{
- float fLeft = aDistance[aLeft[iLeft]];
- float 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++){
- float left = aDistance[aIdx[jj-1]];
- float 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 ){
- double xleft1 = DCOORD(aCell[aLeft[iLeft]].aCoord[iDim*2]);
- double xleft2 = DCOORD(aCell[aLeft[iLeft]].aCoord[iDim*2+1]);
- double xright1 = DCOORD(aCell[aRight[iRight]].aCoord[iDim*2]);
- double 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++){
- float xleft1 = aCell[aIdx[jj-1]].aCoord[iDim*2];
- float xleft2 = aCell[aIdx[jj-1]].aCoord[iDim*2+1];
- float xright1 = aCell[aIdx[jj]].aCoord[iDim*2];
- float 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;
- int iBestSplit;
- float fBestMargin;
-
- 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++){
- float margin = 0.0;
- float fBestOverlap;
- float fBestArea;
- int iBestLeft;
- int nLeft;
-
- for(
- nLeft=RTREE_MINCELLS(pRtree);
- nLeft<=(nCell-RTREE_MINCELLS(pRtree));
- nLeft++
- ){
- RtreeCell left;
- RtreeCell right;
- int kk;
- float overlap;
- float 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);
- 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);
- float 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, 1);
- pLeft = nodeNew(pRtree, pNode, 1);
- pRtree->iDepth++;
- pNode->isDirty = 1;
- writeInt16(pNode->zData, pRtree->iDepth);
- }else{
- pLeft = pNode;
- pRight = nodeNew(pRtree, pLeft->pParent, 1);
- 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. */
- if( (0==pRight->iNode && 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 = nodeParentIndex(pRtree, pLeft);
- nodeOverwriteCell(pRtree, pParent, &leftbbox, iCell);
- AdjustTree(pRtree, pParent, &leftbbox);
- }
- 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;
-}
-
-static int fixLeafParent(Rtree *pRtree, RtreeNode *pLeaf){
- int rc = SQLITE_OK;
- if( pLeaf->iNode!=1 && pLeaf->pParent==0 ){
- sqlite3_bind_int64(pRtree->pReadParent, 1, pLeaf->iNode);
- if( sqlite3_step(pRtree->pReadParent)==SQLITE_ROW ){
- i64 iNode = sqlite3_column_int64(pRtree->pReadParent, 0);
- rc = nodeAcquire(pRtree, iNode, 0, &pLeaf->pParent);
- }else{
- rc = SQLITE_ERROR;
- }
- sqlite3_reset(pRtree->pReadParent);
- if( rc==SQLITE_OK ){
- rc = fixLeafParent(pRtree, pLeaf->pParent);
- }
- }
- return rc;
-}
-
-static int deleteCell(Rtree *, RtreeNode *, int, int);
-
-static int removeNode(Rtree *pRtree, RtreeNode *pNode, int iHeight){
- int rc;
- RtreeNode *pParent;
- int iCell;
-
- assert( pNode->nRef==1 );
-
- /* Remove the entry in the parent cell. */
- iCell = nodeParentIndex(pRtree, pNode);
- pParent = pNode->pParent;
- pNode->pParent = 0;
- if( SQLITE_OK!=(rc = deleteCell(pRtree, pParent, iCell, iHeight+1))
- || SQLITE_OK!=(rc = nodeRelease(pRtree, pParent))
- ){
- 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 void fixBoundingBox(Rtree *pRtree, RtreeNode *pNode){
- RtreeNode *pParent = pNode->pParent;
- 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;
- ii = nodeParentIndex(pRtree, pNode);
- nodeOverwriteCell(pRtree, pParent, &box, ii);
- fixBoundingBox(pRtree, pParent);
- }
-}
-
-/*
-** 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){
- 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.
- */
- if( pNode->iNode!=1 ){
- RtreeNode *pParent = pNode->pParent;
- if( (pParent->iNode!=1 || NCELL(pParent)!=1)
- && (NCELL(pNode)<RTREE_MINCELLS(pRtree))
- ){
- rc = removeNode(pRtree, pNode, iHeight);
- }else{
- fixBoundingBox(pRtree, pNode);
- }
- }
-
- return rc;
-}
-
-static int Reinsert(
- Rtree *pRtree,
- RtreeNode *pNode,
- RtreeCell *pCell,
- int iHeight
-){
- int *aOrder;
- int *aSpare;
- RtreeCell *aCell;
- float *aDistance;
- int nCell;
- float aCenterCoord[RTREE_MAX_DIMENSIONS];
- int iDim;
- int ii;
- int rc = SQLITE_OK;
-
- memset(aCenterCoord, 0, sizeof(float)*RTREE_MAX_DIMENSIONS);
-
- nCell = NCELL(pNode)+1;
-
- /* Allocate the buffers used by this operation. The allocation is
- ** relinquished before this function returns.
- */
- aCell = (RtreeCell *)sqlite3_malloc(nCell * (
- sizeof(RtreeCell) + /* aCell array */
- sizeof(int) + /* aOrder array */
- sizeof(int) + /* aSpare array */
- sizeof(float) /* aDistance array */
- ));
- if( !aCell ){
- return SQLITE_NOMEM;
- }
- aOrder = (int *)&aCell[nCell];
- aSpare = (int *)&aOrder[nCell];
- aDistance = (float *)&aSpare[nCell];
-
- 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]/((float)nCell*2.0);
- }
-
- for(ii=0; ii<nCell; ii++){
- aDistance[ii] = 0.0;
- for(iDim=0; iDim<pRtree->nDim; iDim++){
- float 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 ){
- 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{
- AdjustTree(pRtree, pNode, pCell);
- 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, pNode->iNode, &pInsert);
- if( rc==SQLITE_OK ){
- int rc2;
- rc = rtreeInsertCell(pRtree, pInsert, &cell, 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;
-}
-
-#ifndef NDEBUG
-static int hashIsEmpty(Rtree *pRtree){
- int ii;
- for(ii=0; ii<HASHSIZE; ii++){
- assert( !pRtree->aHash[ii] );
- }
- return 1;
-}
-#endif
-
-/*
-** 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;
-
- rtreeReference(pRtree);
-
- assert(nData>=1);
- assert(hashIsEmpty(pRtree));
-
- /* 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 ){
- i64 iDelete; /* The rowid to delete */
- RtreeNode *pLeaf; /* Leaf node containing record iDelete */
- int iCell; /* Index of iDelete cell in pLeaf */
- RtreeNode *pRoot;
-
- /* Obtain a reference to the root node to initialise 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 ){
- iDelete = sqlite3_value_int64(azData[0]);
- rc = findLeafNode(pRtree, iDelete, &pLeaf);
- }
-
- /* Delete the cell in question from the leaf node. */
- if( rc==SQLITE_OK ){
- int rc2;
- iCell = nodeRowidIndex(pRtree, pLeaf, iDelete);
- 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 ){
- if( rc==SQLITE_OK && NCELL(pRoot)==1 ){
- 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);
- }
- 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);
- }
- }
-
- /* 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 a new record into the r-tree */
- RtreeCell cell;
- int ii;
- RtreeNode *pLeaf;
-
- /* Populate the cell.aCoord[] array. The first coordinate is azData[3]. */
- assert( nData==(pRtree->nDim*2 + 3) );
- if( pRtree->eCoordType==RTREE_COORD_REAL32 ){
- for(ii=0; ii<(pRtree->nDim*2); ii+=2){
- cell.aCoord[ii].f = (float)sqlite3_value_double(azData[ii+3]);
- cell.aCoord[ii+1].f = (float)sqlite3_value_double(azData[ii+4]);
- if( cell.aCoord[ii].f>cell.aCoord[ii+1].f ){
- rc = SQLITE_CONSTRAINT;
- goto constraint;
- }
- }
- }else{
- 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;
- }
- }
- }
-
- /* Figure out the rowid of the new row. */
- if( sqlite3_value_type(azData[2])==SQLITE_NULL ){
- rc = newRowid(pRtree, &cell.iRowid);
- }else{
- cell.iRowid = sqlite3_value_int64(azData[2]);
- sqlite3_bind_int64(pRtree->pReadRowid, 1, cell.iRowid);
- if( SQLITE_ROW==sqlite3_step(pRtree->pReadRowid) ){
- sqlite3_reset(pRtree->pReadRowid);
- rc = SQLITE_CONSTRAINT;
- goto constraint;
- }
- rc = sqlite3_reset(pRtree->pReadRowid);
- }
-
- 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 */
-};
-
-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;
-}
-
-/*
-** This routine queries database handle db for the page-size used by
-** database zDb. If successful, the page-size in bytes is written to
-** *piPageSize and SQLITE_OK returned. Otherwise, and an SQLite error
-** code is returned.
-*/
-static int getPageSize(sqlite3 *db, const char *zDb, int *piPageSize){
- int rc = SQLITE_NOMEM;
- char *zSql;
- sqlite3_stmt *pStmt = 0;
-
- zSql = sqlite3_mprintf("PRAGMA %Q.page_size", zDb);
- if( !zSql ){
- return SQLITE_NOMEM;
- }
-
- rc = sqlite3_prepare_v2(db, zSql, -1, &pStmt, 0);
- sqlite3_free(zSql);
- if( rc!=SQLITE_OK ){
- return rc;
- }
-
- if( SQLITE_ROW==sqlite3_step(pStmt) ){
- *piPageSize = sqlite3_column_int(pStmt, 0);
- }
- return sqlite3_finalize(pStmt);
-}
-
-/*
-** 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;
- int iPageSize = 0;
- Rtree *pRtree;
- int nDb; /* Length of string argv[1] */
- int nName; /* Length of string argv[2] */
- int eCoordType = (int)pAux;
-
- 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;
- }
-
- rc = getPageSize(db, argv[1], &iPageSize);
- if( rc!=SQLITE_OK ){
- return rc;
- }
-
- /* Allocate the sqlite3_vtab structure */
- nDb = strlen(argv[1]);
- nName = 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. By default, use 64 bytes less than
- ** the database page-size. This ensures that each node is stored on
- ** a single database page.
- **
- ** If the databasd page-size is so large that more than RTREE_MAXCELLS
- ** entries would fit in a single node, use a smaller node-size.
- */
- pRtree->iNodeSize = iPageSize-64;
- if( (4+pRtree->nBytesPerCell*RTREE_MAXCELLS)<pRtree->iNodeSize ){
- pRtree->iNodeSize = 4+pRtree->nBytesPerCell*RTREE_MAXCELLS;
- }
-
- /* 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 = 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;
-
- 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],"%d", cell.iRowid);
- nCell = strlen(zCell);
- for(jj=0; jj<tree.nDim*2; jj++){
- sqlite3_snprintf(512-nCell,&zCell[nCell]," %f",(double)cell.aCoord[jj].f);
- nCell = 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){
- 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){
- int rc = SQLITE_OK;
-
- if( rc==SQLITE_OK ){
- int utf8 = SQLITE_UTF8;
- rc = sqlite3_create_function(db, "rtreenode", 2, utf8, 0, rtreenode, 0, 0);
- }
- if( rc==SQLITE_OK ){
- int utf8 = SQLITE_UTF8;
- rc = sqlite3_create_function(db, "rtreedepth", 1, utf8, 0,rtreedepth, 0, 0);
- }
- if( rc==SQLITE_OK ){
- void *c = (void *)RTREE_COORD_REAL32;
- 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;
-}
-
-#if !SQLITE_CORE
-int sqlite3_extension_init(
- sqlite3 *db,
- char **pzErrMsg,
- const sqlite3_api_routines *pApi
-){
- SQLITE_EXTENSION_INIT2(pApi)
- return sqlite3RtreeInit(db);
-}
-#endif
-
-#endif
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