diff -r 000000000000 -r 08ec8eefde2f persistentstorage/sqlite3api/SQLite/rtree.c --- /dev/null Thu Jan 01 00:00:00 1970 +0000 +++ b/persistentstorage/sqlite3api/SQLite/rtree.c Fri Jan 22 11:06:30 2010 +0200 @@ -0,0 +1,2854 @@ +/* +** 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 1.9 2008/09/08 11:07:03 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 +#include + +#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]; +}; + +#define MAX(x,y) ((x) < (y) ? (y) : (x)) +#define MIN(x,y) ((x) > (y) ? (y) : (x)) + +/* +** 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 = 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( nCellzData[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( iCellzData[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; iinDim*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, 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, (int)pAux); +} + +/* +** 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, (int)pAux); +} + +/* +** 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 && iinConstraint; 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->rValuerValue>cell_max; break; + case RTREE_EQ: + bRes = (p->rValue>cell_max || p->rValueaConstraint[] 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; iinConstraint; 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 = (coordrValue); 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 && iiiCell = 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->iCelliCell++){ + 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; iiaConstraint[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->iCelliCell++){ + 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->iCellpNode) ); + } + } + + 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; iinConstraint; 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; jjaConstraintUsage[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; jaConstraintUsage[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].fa1[1].f)) + || ( isInt && (a2[0].ia1[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; iinDim*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( x2iDepth-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; jjiDepth-1) ){ + overlap = cellOverlapEnlargement(pRtree,&cell,pCell,aCell,nCell,iCell); + } +#endif + if( (iCell==0) + || (overlappParent ){ + 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 _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 _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; inDim; 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; jjx4 ) x4 = right; + if( left>x3 ){ + x3 = left; + iCellRight = jj; + } + if( rightmaxNormalInnerWidth ){ + 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; iifDiff ){ + 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; iifWaste ){ + 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( iLeft1 ){ + + 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( iLeftnDim+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; iinDim; ii++){ + int jj; + aaSorted[ii] = &((int *)&aaSorted[pRtree->nDim])[ii*nCell]; + for(jj=0; jjnDim; 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( kk0; 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; iiNode==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; iiRowid ){ + newCellIsRight = 1; + } + if( rc!=SQLITE_OK ){ + goto splitnode_out; + } + } + if( pNode->iNode==1 ){ + for(i=0; iiRowid, 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; iiiNode; + 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)nDim; iDim++){ + aCenterCoord[iDim] += DCOORD(aCell[ii].aCoord[iDim*2]); + aCenterCoord[iDim] += DCOORD(aCell[ii].aCoord[iDim*2+1]); + } + } + for(iDim=0; iDimnDim; iDim++){ + aCenterCoord[iDim] = aCenterCoord[iDim]/((float)nCell*2.0); + } + + for(ii=0; iinDim; 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 && iiiNode 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 && iiiNode 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; iiaHash[ii] ); + } + return 1; +} +#endif + +/* +** The xUpdate method for rtree module virtual tables. +*/ +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 _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 module name +** argv[1] -> database name +** argv[2] -> table name +** argv[...] -> column names... +*/ +static int rtreeInit( + sqlite3 *db, /* Database connection */ + void *pAux, /* Pointer to head of rtree list */ + 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 eCoordType /* One of the RTREE_COORD_* constants */ +){ + int rc = SQLITE_OK; + int iPageSize = 0; + Rtree *pRtree; + int nDb; /* Length of string argv[1] */ + int nName; /* Length of string argv[2] */ + + 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)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*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