/*
** 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.
**
******************************************************************************
*/
#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);
}
/*
** 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
){
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);
}
/*
** Advance the iterator object passed as the only argument. Return true
** if the iterator reaches EOF, or false otherwise.
*/
int sqlite3Fts5PoslistReaderNext(Fts5PoslistReader *pIter){
if( pIter->i>=pIter->n ){
pIter->bEof = 1;
}else{
int iVal;
pIter->i += getVarint32(&pIter->a[pIter->i], iVal);
if( iVal==1 ){
pIter->i += getVarint32(&pIter->a[pIter->i], iVal);
if( pIter->iCol>=0 && iVal>pIter->iCol ){
pIter->bEof = 1;
}else{
pIter->iPos = ((u64)iVal << 32);
pIter->i += getVarint32(&pIter->a[pIter->i], iVal);
}
}
pIter->iPos += (iVal-2);
}
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
){
int rc = SQLITE_OK;
int iCol = (int)(iPos >> 32);
int iOff = (iPos & 0x7FFFFFFF);
if( iCol!=pWriter->iCol ){
fts5BufferAppendVarint(&rc, pBuf, 1);
fts5BufferAppendVarint(&rc, pBuf, iCol);
pWriter->iCol = iCol;
pWriter->iOff = 0;
}
fts5BufferAppendVarint(&rc, pBuf, (iOff - pWriter->iOff) + 2);
return rc;
}