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Use the sqlite3_blob interface for reading values from the %_node shadow
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table in RTREE.  This is a work in progress.  There are still some minor
problems.
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D. Richard Hipp committed Feb 2, 2017
1 parent d9901ae commit ce015fb
Showing 1 changed file with 78 additions and 28 deletions.
106 changes: 78 additions & 28 deletions ext/rtree/rtree.c
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Expand Up @@ -133,6 +133,9 @@ struct Rtree {
RtreeNode *pDeleted;
int iReinsertHeight; /* Height of sub-trees Reinsert() has run on */

/* Blob I/O on xxx_node */
sqlite3_blob *pNodeBlob;

/* Statements to read/write/delete a record from xxx_node */
sqlite3_stmt *pReadNode;
sqlite3_stmt *pWriteNode;
Expand Down Expand Up @@ -615,6 +618,16 @@ static RtreeNode *nodeNew(Rtree *pRtree, RtreeNode *pParent){
return pNode;
}

/*
** Clear the Rtree.pNodeBlob object
*/
static void nodeBlobReset(Rtree *pRtree){
if( pRtree->pNodeBlob ){
sqlite3_blob_close(pRtree->pNodeBlob);
pRtree->pNodeBlob = 0;
}
}

/*
** Obtain a reference to an r-tree node.
*/
Expand All @@ -624,9 +637,8 @@ static int nodeAcquire(
RtreeNode *pParent, /* Either the parent node or NULL */
RtreeNode **ppNode /* OUT: Acquired node */
){
int rc;
int rc2 = SQLITE_OK;
RtreeNode *pNode;
int rc = SQLITE_OK;
RtreeNode *pNode = 0;

/* Check if the requested node is already in the hash table. If so,
** increase its reference count and return it.
Expand All @@ -642,28 +654,42 @@ static int nodeAcquire(
return SQLITE_OK;
}

sqlite3_bind_int64(pRtree->pReadNode, 1, iNode);
rc = sqlite3_step(pRtree->pReadNode);
if( rc==SQLITE_ROW ){
const u8 *zBlob = sqlite3_column_blob(pRtree->pReadNode, 0);
if( pRtree->iNodeSize==sqlite3_column_bytes(pRtree->pReadNode, 0) ){
pNode = (RtreeNode *)sqlite3_malloc(sizeof(RtreeNode)+pRtree->iNodeSize);
if( !pNode ){
rc2 = SQLITE_NOMEM;
}else{
pNode->pParent = pParent;
pNode->zData = (u8 *)&pNode[1];
pNode->nRef = 1;
pNode->iNode = iNode;
pNode->isDirty = 0;
pNode->pNext = 0;
memcpy(pNode->zData, zBlob, pRtree->iNodeSize);
nodeReference(pParent);
}
if( pRtree->pNodeBlob ){
sqlite3_blob *pBlob = pRtree->pNodeBlob;
pRtree->pNodeBlob = 0;
rc = sqlite3_blob_reopen(pBlob, iNode);
pRtree->pNodeBlob = pBlob;
if( rc ){
nodeBlobReset(pRtree);
if( rc==SQLITE_NOMEM ) return rc;
}
}
if( pRtree->pNodeBlob==0 ){
char *zTab = sqlite3_mprintf("%s_node", pRtree->zName);
if( zTab==0 ) return SQLITE_NOMEM;
rc = sqlite3_blob_open(pRtree->db, pRtree->zDb, zTab, "data", iNode, 0,
&pRtree->pNodeBlob);
sqlite3_free(zTab);
}
if( rc ){
nodeBlobReset(pRtree);
*ppNode = 0;
}else if( pRtree->iNodeSize==sqlite3_blob_bytes(pRtree->pNodeBlob) ){
pNode = (RtreeNode *)sqlite3_malloc(sizeof(RtreeNode)+pRtree->iNodeSize);
if( !pNode ){
rc = SQLITE_NOMEM;
}else{
pNode->pParent = pParent;
pNode->zData = (u8 *)&pNode[1];
pNode->nRef = 1;
pNode->iNode = iNode;
pNode->isDirty = 0;
pNode->pNext = 0;
rc = sqlite3_blob_read(pRtree->pNodeBlob, pNode->zData,
pRtree->iNodeSize, 0);
nodeReference(pParent);
}
}
rc = sqlite3_reset(pRtree->pReadNode);
if( rc==SQLITE_OK ) rc = rc2;

/* If the root node was just loaded, set pRtree->iDepth to the height
** of the r-tree structure. A height of zero means all data is stored on
Expand Down Expand Up @@ -909,6 +935,7 @@ static void rtreeReference(Rtree *pRtree){
static void rtreeRelease(Rtree *pRtree){
pRtree->nBusy--;
if( pRtree->nBusy==0 ){
nodeBlobReset(pRtree);
sqlite3_finalize(pRtree->pReadNode);
sqlite3_finalize(pRtree->pWriteNode);
sqlite3_finalize(pRtree->pDeleteNode);
Expand Down Expand Up @@ -947,6 +974,7 @@ static int rtreeDestroy(sqlite3_vtab *pVtab){
if( !zCreate ){
rc = SQLITE_NOMEM;
}else{
nodeBlobReset(pRtree);
rc = sqlite3_exec(pRtree->db, zCreate, 0, 0, 0);
sqlite3_free(zCreate);
}
Expand Down Expand Up @@ -3152,6 +3180,27 @@ static int rtreeUpdate(
return rc;
}

/*
** Called when a transaction starts.
** This is a no-op. But the Virtual Table mechanism needs a method
** here or else it will never call the xRollback and xCommit methods,
** and those methods are necessary for clearing the sqlite3_blob object.
*/
static int rtreeBeginTransaction(sqlite3_vtab *pVtab){
(void)pVtab;
return SQLITE_OK;
}

/*
** Called when a transaction completes (either by COMMIT or ROLLBACK).
** The sqlite3_blob object should be released at this point.
*/
static int rtreeEndTransaction(sqlite3_vtab *pVtab){
Rtree *pRtree = (Rtree *)pVtab;
nodeBlobReset(pRtree);
return SQLITE_OK;
}

/*
** The xRename method for rtree module virtual tables.
*/
Expand All @@ -3173,6 +3222,7 @@ static int rtreeRename(sqlite3_vtab *pVtab, const char *zNewName){
return rc;
}


/*
** This function populates the pRtree->nRowEst variable with an estimate
** of the number of rows in the virtual table. If possible, this is based
Expand Down Expand Up @@ -3232,15 +3282,15 @@ static sqlite3_module rtreeModule = {
rtreeColumn, /* xColumn - read data */
rtreeRowid, /* xRowid - read data */
rtreeUpdate, /* xUpdate - write data */
0, /* xBegin - begin transaction */
rtreeBeginTransaction, /* xBegin - begin transaction */
0, /* xSync - sync transaction */
0, /* xCommit - commit transaction */
0, /* xRollback - rollback transaction */
rtreeEndTransaction, /* xCommit - commit transaction */
rtreeEndTransaction, /* xRollback - rollback transaction */
0, /* xFindFunction - function overloading */
rtreeRename, /* xRename - rename the table */
0, /* xSavepoint */
0, /* xRelease */
0 /* xRollbackTo */
0, /* xRollbackTo */
};

static int rtreeSqlInit(
Expand Down Expand Up @@ -3440,7 +3490,7 @@ static int rtreeInit(
pRtree->zDb = (char *)&pRtree[1];
pRtree->zName = &pRtree->zDb[nDb+1];
pRtree->nDim = (u8)((argc-4)/2);
pRtree->nDim2 = argc - 4;
pRtree->nDim2 = pRtree->nDim*2;
pRtree->nBytesPerCell = 8 + pRtree->nDim2*4;
pRtree->eCoordType = (u8)eCoordType;
memcpy(pRtree->zDb, argv[1], nDb);
Expand Down

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