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-rw-r--r--ext/fts5/fts5_buffer.c299
1 files changed, 299 insertions, 0 deletions
diff --git a/ext/fts5/fts5_buffer.c b/ext/fts5/fts5_buffer.c
new file mode 100644
index 000000000..94fb4216d
--- /dev/null
+++ b/ext/fts5/fts5_buffer.c
@@ -0,0 +1,299 @@
+/*
+** 2014 May 31
+**
+** 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.
+**
+******************************************************************************
+*/
+
+
+#ifdef SQLITE_ENABLE_FTS5
+
+#include "fts5Int.h"
+
+int sqlite3Fts5BufferGrow(int *pRc, Fts5Buffer *pBuf, int nByte){
+ /* A no-op if an error has already occurred */
+ if( *pRc ) return 1;
+
+ if( (pBuf->n + nByte) > pBuf->nSpace ){
+ u8 *pNew;
+ int nNew = pBuf->nSpace ? pBuf->nSpace*2 : 64;
+ while( nNew<(pBuf->n + nByte) ){
+ nNew = nNew * 2;
+ }
+ pNew = sqlite3_realloc(pBuf->p, nNew);
+ if( pNew==0 ){
+ *pRc = SQLITE_NOMEM;
+ return 1;
+ }else{
+ pBuf->nSpace = nNew;
+ pBuf->p = pNew;
+ }
+ }
+ return 0;
+}
+
+/*
+** Encode value iVal as an SQLite varint and append it to the buffer object
+** pBuf. If an OOM error occurs, set the error code in p.
+*/
+void sqlite3Fts5BufferAppendVarint(int *pRc, Fts5Buffer *pBuf, i64 iVal){
+ if( sqlite3Fts5BufferGrow(pRc, pBuf, 9) ) return;
+ pBuf->n += sqlite3PutVarint(&pBuf->p[pBuf->n], iVal);
+}
+
+void sqlite3Fts5Put32(u8 *aBuf, int iVal){
+ aBuf[0] = (iVal>>24) & 0x00FF;
+ aBuf[1] = (iVal>>16) & 0x00FF;
+ aBuf[2] = (iVal>> 8) & 0x00FF;
+ aBuf[3] = (iVal>> 0) & 0x00FF;
+}
+
+int sqlite3Fts5Get32(const u8 *aBuf){
+ return (aBuf[0] << 24) + (aBuf[1] << 16) + (aBuf[2] << 8) + aBuf[3];
+}
+
+void sqlite3Fts5BufferAppend32(int *pRc, Fts5Buffer *pBuf, int iVal){
+ if( sqlite3Fts5BufferGrow(pRc, pBuf, 4) ) return;
+ sqlite3Fts5Put32(&pBuf->p[pBuf->n], iVal);
+ pBuf->n += 4;
+}
+
+/*
+** Append buffer nData/pData to buffer pBuf. If an OOM error occurs, set
+** the error code in p. If an error has already occurred when this function
+** is called, it is a no-op.
+*/
+void sqlite3Fts5BufferAppendBlob(
+ int *pRc,
+ Fts5Buffer *pBuf,
+ int nData,
+ const u8 *pData
+){
+ assert( *pRc || nData>=0 );
+ if( sqlite3Fts5BufferGrow(pRc, pBuf, nData) ) return;
+ memcpy(&pBuf->p[pBuf->n], pData, nData);
+ pBuf->n += nData;
+}
+
+/*
+** Append the nul-terminated string zStr to the buffer pBuf. This function
+** ensures that the byte following the buffer data is set to 0x00, even
+** though this byte is not included in the pBuf->n count.
+*/
+void sqlite3Fts5BufferAppendString(
+ int *pRc,
+ Fts5Buffer *pBuf,
+ const char *zStr
+){
+ int nStr = strlen(zStr);
+ if( sqlite3Fts5BufferGrow(pRc, pBuf, nStr+1) ) return;
+ sqlite3Fts5BufferAppendBlob(pRc, pBuf, nStr, (const u8*)zStr);
+ if( *pRc==SQLITE_OK ) pBuf->p[pBuf->n] = 0x00;
+}
+
+/*
+** Argument zFmt is a printf() style format string. This function performs
+** the printf() style processing, then appends the results to buffer pBuf.
+**
+** Like sqlite3Fts5BufferAppendString(), this function ensures that the byte
+** following the buffer data is set to 0x00, even though this byte is not
+** included in the pBuf->n count.
+*/
+void sqlite3Fts5BufferAppendPrintf(
+ int *pRc,
+ Fts5Buffer *pBuf,
+ char *zFmt, ...
+){
+ if( *pRc==SQLITE_OK ){
+ char *zTmp;
+ va_list ap;
+ va_start(ap, zFmt);
+ zTmp = sqlite3_vmprintf(zFmt, ap);
+ va_end(ap);
+
+ if( zTmp==0 ){
+ *pRc = SQLITE_NOMEM;
+ }else{
+ sqlite3Fts5BufferAppendString(pRc, pBuf, zTmp);
+ sqlite3_free(zTmp);
+ }
+ }
+}
+
+/*
+** Free any buffer allocated by pBuf. Zero the structure before returning.
+*/
+void sqlite3Fts5BufferFree(Fts5Buffer *pBuf){
+ sqlite3_free(pBuf->p);
+ memset(pBuf, 0, sizeof(Fts5Buffer));
+}
+
+/*
+** Zero the contents of the buffer object. But do not free the associated
+** memory allocation.
+*/
+void sqlite3Fts5BufferZero(Fts5Buffer *pBuf){
+ pBuf->n = 0;
+}
+
+/*
+** Set the buffer to contain nData/pData. If an OOM error occurs, leave an
+** the error code in p. If an error has already occurred when this function
+** is called, it is a no-op.
+*/
+void sqlite3Fts5BufferSet(
+ int *pRc,
+ Fts5Buffer *pBuf,
+ int nData,
+ const u8 *pData
+){
+ pBuf->n = 0;
+ sqlite3Fts5BufferAppendBlob(pRc, pBuf, nData, pData);
+}
+
+int sqlite3Fts5PoslistNext64(
+ const u8 *a, int n, /* Buffer containing poslist */
+ int *pi, /* IN/OUT: Offset within a[] */
+ i64 *piOff /* IN/OUT: Current offset */
+){
+ int i = *pi;
+ if( i>=n ){
+ /* EOF */
+ *piOff = -1;
+ return 1;
+ }else{
+ i64 iOff = *piOff;
+ int iVal;
+ i += getVarint32(&a[i], iVal);
+ if( iVal==1 ){
+ i += getVarint32(&a[i], iVal);
+ iOff = ((i64)iVal) << 32;
+ i += getVarint32(&a[i], iVal);
+ }
+ *piOff = iOff + (iVal-2);
+ *pi = i;
+ return 0;
+ }
+}
+
+
+/*
+** Advance the iterator object passed as the only argument. Return true
+** if the iterator reaches EOF, or false otherwise.
+*/
+int sqlite3Fts5PoslistReaderNext(Fts5PoslistReader *pIter){
+ if( sqlite3Fts5PoslistNext64(pIter->a, pIter->n, &pIter->i, &pIter->iPos)
+ || (pIter->iCol>=0 && (pIter->iPos >> 32) > pIter->iCol)
+ ){
+ pIter->bEof = 1;
+ }
+ return pIter->bEof;
+}
+
+int sqlite3Fts5PoslistReaderInit(
+ int iCol, /* If (iCol>=0), this column only */
+ const u8 *a, int n, /* Poslist buffer to iterate through */
+ Fts5PoslistReader *pIter /* Iterator object to initialize */
+){
+ memset(pIter, 0, sizeof(*pIter));
+ pIter->a = a;
+ pIter->n = n;
+ pIter->iCol = iCol;
+ do {
+ sqlite3Fts5PoslistReaderNext(pIter);
+ }while( pIter->bEof==0 && (pIter->iPos >> 32)<iCol );
+ return pIter->bEof;
+}
+
+int sqlite3Fts5PoslistWriterAppend(
+ Fts5Buffer *pBuf,
+ Fts5PoslistWriter *pWriter,
+ i64 iPos
+){
+ static const i64 colmask = ((i64)(0x7FFFFFFF)) << 32;
+ int rc = SQLITE_OK;
+ if( (iPos & colmask) != (pWriter->iPrev & colmask) ){
+ fts5BufferAppendVarint(&rc, pBuf, 1);
+ fts5BufferAppendVarint(&rc, pBuf, (iPos >> 32));
+ pWriter->iPrev = (iPos & colmask);
+ }
+ fts5BufferAppendVarint(&rc, pBuf, (iPos - pWriter->iPrev) + 2);
+ pWriter->iPrev = iPos;
+ return rc;
+}
+
+int sqlite3Fts5PoslistNext(
+ const u8 *a, int n, /* Buffer containing poslist */
+ int *pi, /* IN/OUT: Offset within a[] */
+ int *piCol, /* IN/OUT: Current column */
+ int *piOff /* IN/OUT: Current token offset */
+){
+ int i = *pi;
+ int iVal;
+ if( i>=n ){
+ /* EOF */
+ return 1;
+ }
+ i += getVarint32(&a[i], iVal);
+ if( iVal==1 ){
+ i += getVarint32(&a[i], iVal);
+ *piCol = iVal;
+ *piOff = 0;
+ i += getVarint32(&a[i], iVal);
+ }
+ *piOff += (iVal-2);
+ *pi = i;
+ return 0;
+}
+
+void sqlite3Fts5BufferAppendListElem(
+ int *pRc, /* IN/OUT: Error code */
+ Fts5Buffer *pBuf, /* Buffer to append to */
+ const char *z, int n /* Value to append to buffer */
+){
+ int bParen = (n==0);
+ int nMax = n*2 + 2 + 1;
+ u8 *pOut;
+ int i;
+
+ /* Ensure the buffer has space for the new list element */
+ if( sqlite3Fts5BufferGrow(pRc, pBuf, nMax) ) return;
+ pOut = &pBuf->p[pBuf->n];
+
+ /* Figure out if we need the enclosing {} */
+ for(i=0; i<n && bParen==0; i++){
+ if( z[i]=='"' || z[i]==' ' ){
+ bParen = 1;
+ }
+ }
+
+ if( bParen ) *pOut++ = '{';
+ for(i=0; i<n; i++){
+ *pOut++ = z[i];
+ }
+ if( bParen ) *pOut++ = '}';
+
+ pBuf->n = pOut - pBuf->p;
+ *pOut = '\0';
+}
+
+void *sqlite3Fts5MallocZero(int *pRc, int nByte){
+ void *pRet = 0;
+ if( *pRc==SQLITE_OK ){
+ pRet = sqlite3_malloc(nByte);
+ if( pRet==0 && nByte>0 ){
+ *pRc = SQLITE_NOMEM;
+ }else{
+ memset(pRet, 0, nByte);
+ }
+ }
+ return pRet;
+}
+#endif /* SQLITE_ENABLE_FTS5 */
+
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