}
}
-
+/*
+** This function is used to process a single interior node when searching
+** a b-tree for a term or term prefix. The node data is passed to this
+** function via the zNode/nNode parameters. The term to search for is
+** passed in zTerm/nTerm.
+**
+** If piFirst is not NULL, then this function sets *piFirst to the blockid
+** of the child node that heads the sub-tree that may contain the term.
+**
+** If piLast is not NULL, then *piLast is set to the right-most child node
+** that heads a sub-tree that may contain a term for which zTerm/nTerm is
+** a prefix.
+**
+** If an OOM error occurs, SQLITE_NOMEM is returned. Otherwise, SQLITE_OK.
+*/
static int fts3ScanInteriorNode(
Fts3Table *p, /* Virtual table handle */
const char *zTerm, /* Term to select leaves for */
const char *zEnd = &zCsr[nNode];/* End of interior node buffer */
char *zBuffer = 0; /* Buffer to load terms into */
int nAlloc = 0; /* Size of allocated buffer */
+ int isFirstTerm = 1; /* True when processing first term on page */
+ sqlite3_int64 iChild; /* Block id of child node to descend to */
- int isFirstTerm = 1; /* True when processing first term on page */
- int dummy;
- sqlite3_int64 iChild; /* Block id of child node to descend to */
- int nBlock; /* Size of child node in bytes */
-
- zCsr += sqlite3Fts3GetVarint32(zCsr, &dummy);
+ /* Skip over the 'height' varint that occurs at the start of every
+ ** interior node. Then load the blockid of the left-child of the b-tree
+ ** node into variable iChild. */
+ zCsr += sqlite3Fts3GetVarint(zCsr, &iChild);
zCsr += sqlite3Fts3GetVarint(zCsr, &iChild);
while( zCsr<zEnd && (piFirst || piLast) ){
- int cmp; /* memcmp() result */
- int nSuffix; /* Size of term suffix */
- int nPrefix = 0; /* Size of term prefix */
- int nBuffer; /* Total term size */
+ int cmp; /* memcmp() result */
+ int nSuffix; /* Size of term suffix */
+ int nPrefix = 0; /* Size of term prefix */
+ int nBuffer; /* Total term size */
- /* Load the next term on the node into zBuffer */
+ /* Load the next term on the node into zBuffer. Use realloc() to expand
+ ** the size of zBuffer if required. */
if( !isFirstTerm ){
zCsr += sqlite3Fts3GetVarint32(zCsr, &nPrefix);
}
/*
-** The buffer pointed to by argument zNode (size nNode bytes) contains the
-** root node of a b-tree segment. The segment is guaranteed to be at least
-** one level high (i.e. the root node is not also a leaf). If successful,
-** this function locates the leaf node of the segment that may contain the
-** term specified by arguments zTerm and nTerm and writes its block number
-** to *piLeaf.
-**
-** It is possible that the returned leaf node does not contain the specified
-** term. However, if the segment does contain said term, it is stored on
-** the identified leaf node. Because this function only inspects interior
-** segment nodes (and never loads leaf nodes into memory), it is not possible
-** to be sure.
+** The buffer pointed to by argument zNode (size nNode bytes) contains an
+** interior node of a b-tree segment. The zTerm buffer (size nTerm bytes)
+** contains a term. This function searches the sub-tree headed by the zNode
+** node for the range of leaf nodes that may contain the specified term
+** or terms for which the specified term is a prefix.
+**
+** If piLeaf is not NULL, then *piLeaf is set to the blockid of the
+** left-most leaf node in the tree that may contain the specified term.
+** If piLeaf2 is not NULL, then *piLeaf2 is set to the blockid of the
+** right-most leaf node that may contain a term for which the specified
+** term is a prefix.
+**
+** It is possible that the range of returned leaf nodes does not contain
+** the specified term or any terms for which it is a prefix. However, if the
+** segment does contain any such terms, they are stored within the identified
+** range. Because this function only inspects interior segment nodes (and
+** never loads leaf nodes into memory), it is not possible to be sure.
**
** If an error occurs, an error code other than SQLITE_OK is returned.
*/
int rc; /* Return code */
int iHeight; /* Height of this node in tree */
+ assert( piLeaf || piLeaf2 );
+
sqlite3Fts3GetVarint32(zNode, &iHeight);
rc = fts3ScanInteriorNode(p, zTerm, nTerm, zNode, nNode, piLeaf, piLeaf2);
if( rc==SQLITE_OK && iHeight>1 ){
- const char *zBlob;
- int nBlob;
+ char *zBlob = 0; /* Blob read from %_segments table */
+ int nBlob; /* Size of zBlob in bytes */
if( piLeaf && piLeaf2 && (*piLeaf!=*piLeaf2) ){
rc = sqlite3Fts3ReadBlock(p, *piLeaf, &zBlob, &nBlob);
if( rc==SQLITE_OK ){
rc = fts3SelectLeaf(p, zTerm, nTerm, zBlob, nBlob, piLeaf, 0);
}
+ sqlite3_free(zBlob);
piLeaf = 0;
+ zBlob = 0;
}
rc = sqlite3Fts3ReadBlock(p, piLeaf ? *piLeaf : *piLeaf2, &zBlob, &nBlob);
if( rc==SQLITE_OK ){
rc = fts3SelectLeaf(p, zTerm, nTerm, zBlob, nBlob, piLeaf, piLeaf2);
}
+ sqlite3_free(zBlob);
}
return rc;
*/
rc = sqlite3Fts3SegReaderNew(p, iAge, 0, 0, 0, zRoot, nRoot, &pNew);
}else{
- int rc2; /* Return value of sqlite3Fts3ReadBlock() */
sqlite3_int64 i1; /* First leaf that may contain zTerm */
- sqlite3_int64 i2; /* Last leaf that may contain zTerm */
+ sqlite3_int64 i2; /* Final leaf that may contain zTerm */
rc = fts3SelectLeaf(p, zTerm, nTerm, zRoot, nRoot, &i1, (isPrefix?&i2:0));
if( isPrefix==0 ) i2 = i1;
if( rc==SQLITE_OK ){
rc = sqlite3Fts3SegReaderNew(p, iAge, i1, i2, 0, 0, 0, &pNew);
}
-
- /* The following call to ReadBlock() serves to reset the SQL statement
- ** used to retrieve blocks of data from the %_segments table. If it is
- ** not reset here, then it may remain classified as an active statement
- ** by SQLite, which may lead to "DROP TABLE" or "DETACH" commands
- ** failing.
- */
- rc2 = sqlite3Fts3ReadBlock(p, 0, 0, 0);
- if( rc==SQLITE_OK ){
- rc = rc2;
- }
}
- iAge++;
+ assert( (pNew==0)==(rc!=SQLITE_OK) );
/* If a new Fts3SegReader was allocated, add it to the array. */
- assert( pNew!=0 || rc!=SQLITE_OK );
if( rc==SQLITE_OK ){
rc = fts3SegReaderArrayAdd(&pArray, pNew);
- }else{
- sqlite3Fts3SegReaderFree(p, pNew);
}
if( rc==SQLITE_OK ){
rc = sqlite3Fts3SegReaderCost(pCsr, pNew, &pArray->nCost);
}
+ iAge++;
}
if( rc==SQLITE_DONE ){
return rc;
}
-static void fts3DoclistStripPositions(char *aList, int *pnList){
+/*
+** This function removes the position information from a doclist. When
+** called, buffer aList (size *pnList bytes) contains a doclist that includes
+** position information. This function removes the position information so
+** that aList contains only docids, and adjusts *pnList to reflect the new
+** (possibly reduced) size of the doclist.
+*/
+static void fts3DoclistStripPositions(
+ char *aList, /* IN/OUT: Buffer containing doclist */
+ int *pnList /* IN/OUT: Size of doclist in bytes */
+){
if( aList ){
char *aEnd = &aList[*pnList]; /* Pointer to one byte after EOF */
char *p = aList; /* Input cursor */
char *pOut = aList; /* Output cursor */
- sqlite3_int64 iPrev = 0;
while( p<aEnd ){
sqlite3_int64 delta;
return rc;
}
+/*
+** This function merges two doclists according to the requirements of a
+** NEAR operator.
+**
+** Both input doclists must include position information. The output doclist
+** includes position information if the first argument to this function
+** is MERGE_POS_NEAR, or does not if it is MERGE_NEAR.
+*/
static int fts3NearMerge(
int mergetype, /* MERGE_POS_NEAR or MERGE_NEAR */
int nNear, /* Parameter to NEAR operator */
char **paOut, /* OUT: Results of merge (malloced) */
int *pnOut /* OUT: Sized of output buffer */
){
- char *aOut;
- int rc;
+ char *aOut; /* Buffer to write output doclist to */
+ int rc; /* Return code */
assert( mergetype==MERGE_POS_NEAR || MERGE_NEAR );
return rc;
}
+/*
+** This function is used as part of the processing for the snippet() and
+** offsets() functions.
+**
+** Both pLeft and pRight are expression nodes of type FTSQUERY_PHRASE. Both
+** have their respective doclists (including position information) loaded
+** in Fts3Expr.aDoclist/nDoclist. This function removes all entries from
+** each doclist that are not within nNear tokens of a corresponding entry
+** in the other doclist.
+*/
int sqlite3Fts3ExprNearTrim(Fts3Expr *pLeft, Fts3Expr *pRight, int nNear){
- int rc;
+ int rc; /* Return code */
+
+ assert( pLeft->eType==FTSQUERY_PHRASE );
+ assert( pRight->eType==FTSQUERY_PHRASE );
+ assert( pLeft->isLoaded && pRight->isLoaded );
+
if( pLeft->aDoclist==0 || pRight->aDoclist==0 ){
sqlite3_free(pLeft->aDoclist);
sqlite3_free(pRight->aDoclist);
pLeft->aDoclist = 0;
rc = SQLITE_OK;
}else{
- char *aOut;
- int nOut;
+ char *aOut; /* Buffer in which to assemble new doclist */
+ int nOut; /* Size of buffer aOut in bytes */
rc = fts3NearMerge(MERGE_POS_NEAR, nNear,
pLeft->pPhrase->nToken, pLeft->aDoclist, pLeft->nDoclist,
return rc;
}
-typedef struct ExprAndCost ExprAndCost;
-struct ExprAndCost {
- Fts3Expr *pExpr;
- int nCost;
-};
-
-int fts3ExprCost(Fts3Expr *pExpr){
- int nCost; /* Return value */
- if( pExpr->eType==FTSQUERY_PHRASE ){
- Fts3Phrase *pPhrase = pExpr->pPhrase;
- int ii;
- nCost = 0;
- for(ii=0; ii<pPhrase->nToken; ii++){
- nCost += pPhrase->aToken[ii].pArray->nCost;
- }
- }else{
- nCost = fts3ExprCost(pExpr->pLeft) + fts3ExprCost(pExpr->pRight);
- }
- return nCost;
-}
-
-static void fts3ExprAssignCosts(
- Fts3Expr *pExpr, /* Expression to create seg-readers for */
- ExprAndCost **ppExprCost /* OUT: Write to *ppExprCost */
-){
- if( pExpr->eType==FTSQUERY_AND ){
- fts3ExprAssignCosts(pExpr->pLeft, ppExprCost);
- fts3ExprAssignCosts(pExpr->pRight, ppExprCost);
- }else{
- (*ppExprCost)->pExpr = pExpr;
- (*ppExprCost)->nCost = fts3ExprCost(pExpr);;
- (*ppExprCost)++;
- }
-}
+/*
+** Allocate an Fts3SegReaderArray for each token in the expression pExpr.
+** The allocated objects are stored in the Fts3PhraseToken.pArray member
+** variables of each token structure.
+*/
static int fts3ExprAllocateSegReaders(
Fts3Cursor *pCsr, /* FTS3 table */
Fts3Expr *pExpr, /* Expression to create seg-readers for */
}
if( pExpr->eType==FTSQUERY_PHRASE ){
- Fts3Table *p = (Fts3Table *)pCsr->base.pVtab;
Fts3Phrase *pPhrase = pExpr->pPhrase;
int ii;
return rc;
}
+/*
+** Free the Fts3SegReaderArray objects associated with each token in the
+** expression pExpr. In other words, this function frees the resources
+** allocated by fts3ExprAllocateSegReaders().
+*/
static void fts3ExprFreeSegReaders(Fts3Expr *pExpr){
if( pExpr ){
Fts3Phrase *pPhrase = pExpr->pPhrase;
}
/*
-** Evaluate the full-text expression pExpr against fts3 table pTab. Store
-** the resulting doclist in *paOut and *pnOut. This routine mallocs for
-** the space needed to store the output. The caller is responsible for
+** Return the sum of the costs of all tokens in the expression pExpr. This
+** function must be called after Fts3SegReaderArrays have been allocated
+** for all tokens using fts3ExprAllocateSegReaders().
+*/
+int fts3ExprCost(Fts3Expr *pExpr){
+ int nCost; /* Return value */
+ if( pExpr->eType==FTSQUERY_PHRASE ){
+ Fts3Phrase *pPhrase = pExpr->pPhrase;
+ int ii;
+ nCost = 0;
+ for(ii=0; ii<pPhrase->nToken; ii++){
+ nCost += pPhrase->aToken[ii].pArray->nCost;
+ }
+ }else{
+ nCost = fts3ExprCost(pExpr->pLeft) + fts3ExprCost(pExpr->pRight);
+ }
+ return nCost;
+}
+
+/*
+** The following is a helper function (and type) for fts3EvalExpr(). It
+** must be called after Fts3SegReaders have been allocated for every token
+** in the expression. See the context it is called from in fts3EvalExpr()
+** for further explanation.
+*/
+typedef struct ExprAndCost ExprAndCost;
+struct ExprAndCost {
+ Fts3Expr *pExpr;
+ int nCost;
+};
+static void fts3ExprAssignCosts(
+ Fts3Expr *pExpr, /* Expression to create seg-readers for */
+ ExprAndCost **ppExprCost /* OUT: Write to *ppExprCost */
+){
+ if( pExpr->eType==FTSQUERY_AND ){
+ fts3ExprAssignCosts(pExpr->pLeft, ppExprCost);
+ fts3ExprAssignCosts(pExpr->pRight, ppExprCost);
+ }else{
+ (*ppExprCost)->pExpr = pExpr;
+ (*ppExprCost)->nCost = fts3ExprCost(pExpr);;
+ (*ppExprCost)++;
+ }
+}
+
+/*
+** Evaluate the full-text expression pExpr against FTS3 table pTab. Store
+** the resulting doclist in *paOut and *pnOut. This routine mallocs for
+** the space needed to store the output. The caller is responsible for
** freeing the space when it has finished.
+**
+** This function is called in two distinct contexts:
+**
+** * From within the virtual table xFilter() method. In this case, the
+** output doclist contains entries for all rows in the table, based on
+** data read from the full-text index.
+**
+** In this case, if the query expression contains one or more tokens that
+** are very common, then the returned doclist may contain a superset of
+** the documents that actually match the expression.
+**
+** * From within the virtual table xNext() method. This call is only made
+** if the call from within xFilter() found that there were very common
+** tokens in the query expression and did return a superset of the
+** matching documents. In this case the returned doclist contains only
+** entries that correspond to the current row of the table. Instead of
+** reading the data for each token from the full-text index, the data is
+** already available in-memory in the Fts3PhraseToken.pDeferred structures.
+** See fts3EvalDeferred() for how it gets there.
+**
+** In the first case above, Fts3Cursor.doDeferred==0. In the second (if it is
+** required) Fts3Cursor.doDeferred==1.
+**
+** If the SQLite invokes the snippet(), offsets() or matchinfo() function
+** as part of a SELECT on an FTS3 table, this function is called on each
+** individual phrase expression in the query. If there were very common tokens
+** found in the xFilter() call, then this function is called once for phrase
+** for each row visited, and the returned doclist contains entries for the
+** current row only. Otherwise, if there were no very common tokens, then this
+** function is called once only for each phrase in the query and the returned
+** doclist contains entries for all rows of the table.
+**
+** Fts3Cursor.doDeferred==1 when this function is called on phrases as a
+** result of a snippet(), offsets() or matchinfo() invocation.
*/
static int fts3EvalExpr(
Fts3Cursor *p, /* Virtual table cursor handle */
}
/*
-**
-*/
-static int fts3EvalDeferred(Fts3Cursor *pCsr, int *pbRes){
+** This function is called from within xNext() for each row visited by
+** an FTS3 query. If evaluating the FTS3 query expression within xFilter()
+** was able to determine the exact set of matching rows, this function sets
+** *pbRes to true and returns SQLITE_IO immediately.
+**
+** Otherwise, if evaluating the query expression within xFilter() returned a
+** superset of the matching documents instead of an exact set (this happens
+** when the query includes very common tokens and it is deemed too expensive to
+** load their doclists from disk), this function tests if the current row
+** really does match the FTS3 query.
+**
+** If an error occurs, an SQLite error code is returned. Otherwise, SQLITE_OK
+** is returned and *pbRes is set to true if the current row matches the
+** FTS3 query (and should be included in the results returned to SQLite), or
+** false otherwise.
+*/
+static int fts3EvalDeferred(
+ Fts3Cursor *pCsr, /* FTS3 cursor pointing at row to test */
+ int *pbRes /* OUT: Set to true if row is a match */
+){
int rc = SQLITE_OK;
if( pCsr->pDeferred==0 ){
*pbRes = 1;
** number idxNum-FTS3_FULLTEXT_SEARCH, 0 indexed. argv[0] is the right-hand
** side of the MATCH operator.
*/
-/* TODO(shess) Upgrade the cursor initialization and destruction to
-** account for fts3FilterMethod() being called multiple times on the
-** same cursor. The current solution is very fragile. Apply fix to
-** fts3 as appropriate.
-*/
static int fts3FilterMethod(
sqlite3_vtab_cursor *pCursor, /* The cursor used for this query */
int idxNum, /* Strategy index */
if( pCsr->aDoclist ){
*pRowid = pCsr->iPrevId;
}else{
+ /* This branch runs if the query is implemented using a full-table scan
+ ** (not using the full-text index). In this case grab the rowid from the
+ ** SELECT statement.
+ */
+ assert( pCsr->isRequireSeek==0 );
*pRowid = sqlite3_column_int64(pCsr->pStmt, 0);
}
return SQLITE_OK;
}
/*
-** The fts3 built-in tokenizers - "simple" and "porter" - are implemented
-** in files fts3_tokenizer1.c and fts3_porter.c respectively. The following
-** two forward declarations are for functions declared in these files
-** used to retrieve the respective implementations.
+** The fts3 built-in tokenizers - "simple", "porter" and "icu"- are
+** implemented in files fts3_tokenizer1.c, fts3_porter.c and fts3_icu.c
+** respectively. The following three forward declarations are for functions
+** declared in these files used to retrieve the respective implementations.
**
** Calling sqlite3Fts3SimpleTokenizerModule() sets the value pointed
** to by the argument to point to the "simple" tokenizer implementation.
-** Function ...PorterTokenizerModule() sets *pModule to point to the
-** porter tokenizer/stemmer implementation.
+** And so on.
*/
void sqlite3Fts3SimpleTokenizerModule(sqlite3_tokenizer_module const**ppModule);
void sqlite3Fts3PorterTokenizerModule(sqlite3_tokenizer_module const**ppModule);
+#ifdef SQLITE_ENABLE_ICU
void sqlite3Fts3IcuTokenizerModule(sqlite3_tokenizer_module const**ppModule);
+#endif
/*
** Initialise the fts3 extension. If this extension is built as part
sqlite3_int64 iLeafEndBlock; /* Rowid of final leaf block to traverse */
sqlite3_int64 iEndBlock; /* Rowid of final block in segment (or 0) */
sqlite3_int64 iCurrentBlock; /* Current leaf block (or 0) */
- sqlite3_blob *pBlob; /* Blob open on iStartBlock */
char *aNode; /* Pointer to node data (or NULL) */
int nNode; /* Size of buffer at aNode (or 0) */
- int nTermAlloc; /* Allocated size of zTerm buffer */
Fts3HashElem **ppNextElem;
/* Variables set by fts3SegReaderNext(). These may be read directly
*/
int nTerm; /* Number of bytes in current term */
char *zTerm; /* Pointer to current term */
+ int nTermAlloc; /* Allocated size of zTerm buffer */
char *aDoclist; /* Pointer to doclist of current entry */
int nDoclist; /* Size of doclist in current entry */
#define SQL_DELETE_SEGDIR_BY_LEVEL 16
#define SQL_DELETE_SEGMENTS_RANGE 17
#define SQL_CONTENT_INSERT 18
-#define SQL_GET_BLOCK 19
-#define SQL_DELETE_DOCSIZE 20
-#define SQL_REPLACE_DOCSIZE 21
-#define SQL_SELECT_DOCSIZE 22
-#define SQL_SELECT_DOCTOTAL 23
-#define SQL_REPLACE_DOCTOTAL 24
+#define SQL_DELETE_DOCSIZE 19
+#define SQL_REPLACE_DOCSIZE 20
+#define SQL_SELECT_DOCSIZE 21
+#define SQL_SELECT_DOCTOTAL 22
+#define SQL_REPLACE_DOCTOTAL 23
/*
** This function is used to obtain an SQLite prepared statement handle
/* 16 */ "DELETE FROM %Q.'%q_segdir' WHERE level = ?",
/* 17 */ "DELETE FROM %Q.'%q_segments' WHERE blockid BETWEEN ? AND ?",
/* 18 */ "INSERT INTO %Q.'%q_content' VALUES(%z)",
-/* 19 */ "SELECT block FROM %Q.'%q_segments' WHERE blockid = ?",
-/* 20 */ "DELETE FROM %Q.'%q_docsize' WHERE docid = ?",
-/* 21 */ "REPLACE INTO %Q.'%q_docsize' VALUES(?,?)",
-/* 22 */ "SELECT size FROM %Q.'%q_docsize' WHERE docid=?",
-/* 23 */ "SELECT value FROM %Q.'%q_stat' WHERE id=0",
-/* 24 */ "REPLACE INTO %Q.'%q_stat' VALUES(0,?)",
+/* 19 */ "DELETE FROM %Q.'%q_docsize' WHERE docid = ?",
+/* 20 */ "REPLACE INTO %Q.'%q_docsize' VALUES(?,?)",
+/* 21 */ "SELECT size FROM %Q.'%q_docsize' WHERE docid=?",
+/* 22 */ "SELECT value FROM %Q.'%q_stat' WHERE id=0",
+/* 23 */ "REPLACE INTO %Q.'%q_stat' VALUES(0,?)",
};
int rc = SQLITE_OK;
sqlite3_stmt *pStmt;
}
-/*
-** Read a single block from the %_segments table. If the specified block
-** does not exist, return SQLITE_CORRUPT. If some other error (malloc, IO
-** etc.) occurs, return the appropriate SQLite error code.
-**
-** Otherwise, if successful, set *pzBlock to point to a buffer containing
-** the block read from the database, and *pnBlock to the size of the read
-** block in bytes.
-**
-** WARNING: The returned buffer is only valid until the next call to
-** sqlite3Fts3ReadBlock().
-*/
-int sqlite3Fts3ReadBlock(
- Fts3Table *p,
- sqlite3_int64 iBlock,
- char const **pzBlock,
- int *pnBlock
-){
- sqlite3_stmt *pStmt;
- int rc = fts3SqlStmt(p, SQL_GET_BLOCK, &pStmt, 0);
- if( rc!=SQLITE_OK ) return rc;
- sqlite3_reset(pStmt);
-
- if( pzBlock ){
- sqlite3_bind_int64(pStmt, 1, iBlock);
- rc = sqlite3_step(pStmt);
- if( rc!=SQLITE_ROW ){
- return (rc==SQLITE_DONE ? SQLITE_CORRUPT : rc);
- }
-
- *pnBlock = sqlite3_column_bytes(pStmt, 0);
- *pzBlock = (char *)sqlite3_column_blob(pStmt, 0);
- if( sqlite3_column_type(pStmt, 0)!=SQLITE_BLOB ){
- return SQLITE_CORRUPT;
- }
- }
- return SQLITE_OK;
-}
-
/*
** This function ensures that the caller has obtained a shared-cache
** table-lock on the %_content table. This is required before reading
return SQLITE_OK;
}
+/*
+** Discard the contents of the pending-terms hash table.
+*/
void sqlite3Fts3PendingTermsClear(Fts3Table *p){
Fts3HashElem *pElem;
for(pElem=fts3HashFirst(&p->pendingTerms); pElem; pElem=fts3HashNext(pElem)){
** The %_segments table is declared as follows:
**
** CREATE TABLE %_segments(blockid INTEGER PRIMARY KEY, block BLOB)
+**
+** This function reads data from a single row of the %_segments table. The
+** specific row is identified by the iBlockid parameter. If paBlob is not
+** NULL, then a buffer is allocated using sqlite3_malloc() and populated
+** with the contents of the blob stored in the "block" column of the
+** identified table row is. Whether or not paBlob is NULL, *pnBlob is set
+** to the size of the blob in bytes before returning.
+**
+** If an error occurs, or the table does not contain the specified row,
+** an SQLite error code is returned. Otherwise, SQLITE_OK is returned. If
+** paBlob is non-NULL, then it is the responsibility of the caller to
+** eventually free the returned buffer.
+**
+** This function may leave an open sqlite3_blob* handle in the
+** Fts3Table.pSegments variable. This handle is reused by subsequent calls
+** to this function. The handle may be closed by calling the
+** sqlite3Fts3SegmentsClose() function. Reusing a blob handle is a handy
+** performance improvement, but the blob handle should always be closed
+** before control is returned to the user (to prevent a lock being held
+** on the database file for longer than necessary). Thus, any virtual table
+** method (xFilter etc.) that may directly or indirectly call this function
+** must call sqlite3Fts3SegmentsClose() before returning.
*/
-static int fts3SegmentsBlob(
- Fts3Table *p,
- sqlite3_int64 iSegment,
- char **paBlob,
- int *pnBlob
+int sqlite3Fts3ReadBlock(
+ Fts3Table *p, /* FTS3 table handle */
+ sqlite3_int64 iBlockid, /* Access the row with blockid=$iBlockid */
+ char **paBlob, /* OUT: Blob data in malloc'd buffer */
+ int *pnBlob /* OUT: Size of blob data */
){
- int rc;
+ int rc; /* Return code */
+
+ /* pnBlob must be non-NULL. paBlob may be NULL or non-NULL. */
+ assert( pnBlob);
if( p->pSegments ){
- rc = sqlite3_blob_reopen(p->pSegments, iSegment);
+ rc = sqlite3_blob_reopen(p->pSegments, iBlockid);
}else{
if( 0==p->zSegmentsTbl ){
p->zSegmentsTbl = sqlite3_mprintf("%s_segments", p->zName);
if( 0==p->zSegmentsTbl ) return SQLITE_NOMEM;
}
rc = sqlite3_blob_open(
- p->db, p->zDb, p->zSegmentsTbl, "block", iSegment, 0, &p->pSegments
+ p->db, p->zDb, p->zSegmentsTbl, "block", iBlockid, 0, &p->pSegments
);
}
return rc;
}
+/*
+** Close the blob handle at p->pSegments, if it is open. See comments above
+** the sqlite3Fts3ReadBlock() function for details.
+*/
void sqlite3Fts3SegmentsClose(Fts3Table *p){
sqlite3_blob_close(p->pSegments);
p->pSegments = 0;
}
-
/*
** Move the iterator passed as the first argument to the next term in the
** segment. If successful, SQLITE_OK is returned. If there is no next term,
}
if( !pNext || pNext>=&pReader->aNode[pReader->nNode] ){
- sqlite3_blob *pBlob;
- int rc;
+ int rc; /* Return code from Fts3ReadBlock() */
if( fts3SegReaderIsPending(pReader) ){
Fts3HashElem *pElem = *(pReader->ppNextElem);
/* If iCurrentBlock>=iLeafEndBlock, this is an EOF condition. All leaf
** blocks have already been traversed. */
+ assert( pReader->iCurrentBlock<=pReader->iLeafEndBlock );
if( pReader->iCurrentBlock>=pReader->iLeafEndBlock ){
return SQLITE_OK;
}
- rc = fts3SegmentsBlob(
+ rc = sqlite3Fts3ReadBlock(
p, ++pReader->iCurrentBlock, &pReader->aNode, &pReader->nNode
);
-
- if( rc!=SQLITE_OK ){
- return rc;
- }
+ if( rc!=SQLITE_OK ) return rc;
pNext = pReader->aNode;
}
Fts3Table *p = (Fts3Table*)pCsr->base.pVtab;
int rc = SQLITE_OK; /* Return code */
int nCost = 0; /* Cost in bytes to return */
- sqlite3_int64 iLeaf; /* Used to iterate through required leaves */
int pgsz = p->nPgsz; /* Database page size */
/* If this seg-reader is reading the pending-terms table, or if all data
** confirms this).
*/
for(iBlock=pReader->iStartBlock; iBlock<=pReader->iLeafEndBlock; iBlock++){
- rc = fts3SegmentsBlob(p, iBlock, 0, &nBlob);
+ rc = sqlite3Fts3ReadBlock(p, iBlock, 0, &nBlob);
if( rc!=SQLITE_OK ) break;
if( (nBlob+35)>pgsz ){
int nOvfl = (nBlob + 34)/pgsz;
}
rc = fts3SegReaderNext(p, pReader);
- finished:
if( rc==SQLITE_OK ){
*ppReader = pReader;
}else{
** (according to memcmp) than the previous term.
*/
static int fts3NodeAddTerm(
- Fts3Table *p, /* Virtual table handle */
+ Fts3Table *p, /* Virtual table handle */
SegmentNode **ppTree, /* IN/OUT: SegmentNode handle */
int isCopyTerm, /* True if zTerm/nTerm is transient */
const char *zTerm, /* Pointer to buffer containing term */
int i; /* Iterator variable */
int rc; /* Return code */
int iIdx; /* Index of new segment */
- int iNewLevel; /* Level to create new segment at */
+ int iNewLevel = 0; /* Level to create new segment at */
sqlite3_stmt *pStmt = 0;
SegmentWriter *pWriter = 0;
int nSegment = 0; /* Number of segments being merged */
iDocid = sqlite3_column_int64(pCsr->pStmt, 0);
for(i=0; i<p->nColumn && rc==SQLITE_OK; i++){
- const char *zText = sqlite3_column_text(pCsr->pStmt, i+1);
+ const char *zText = (const char *)sqlite3_column_text(pCsr->pStmt, i+1);
sqlite3_tokenizer_cursor *pTC = 0;
rc = pModule->xOpen(pT, zText, -1, &pTC);
/* If this is a DELETE or UPDATE operation, remove the old record. */
if( sqlite3_value_type(apVal[0])!=SQLITE_NULL ){
- int isEmpty;
+ int isEmpty = 0;
rc = fts3IsEmpty(p, apVal, &isEmpty);
if( rc==SQLITE_OK ){
if( isEmpty ){
projects / thirdparty / sqlite.git / commitdiff
