sqlite3/ext/fts5/fts5_buffer.c

409 lines
10 KiB
C
Raw Normal View History

2023-06-27 18:34:42 +08:00
/*
** 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 sqlite3Fts5BufferSize(int *pRc, Fts5Buffer *pBuf, u32 nByte){
if( (u32)pBuf->nSpace<nByte ){
u64 nNew = pBuf->nSpace ? pBuf->nSpace : 64;
u8 *pNew;
while( nNew<nByte ){
nNew = nNew * 2;
}
pNew = sqlite3_realloc64(pBuf->p, nNew);
if( pNew==0 ){
*pRc = SQLITE_NOMEM;
return 1;
}else{
pBuf->nSpace = (int)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( fts5BufferGrow(pRc, pBuf, 9) ) return;
pBuf->n += sqlite3Fts5PutVarint(&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 (int)((((u32)aBuf[0])<<24) + (aBuf[1]<<16) + (aBuf[2]<<8) + aBuf[3]);
}
/*
** 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,
u32 nData,
const u8 *pData
){
if( nData ){
if( fts5BufferGrow(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 = (int)strlen(zStr);
sqlite3Fts5BufferAppendBlob(pRc, pBuf, nStr+1, (const u8*)zStr);
pBuf->n--;
}
/*
** 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);
}
}
}
char *sqlite3Fts5Mprintf(int *pRc, const char *zFmt, ...){
char *zRet = 0;
if( *pRc==SQLITE_OK ){
va_list ap;
va_start(ap, zFmt);
zRet = sqlite3_vmprintf(zFmt, ap);
va_end(ap);
if( zRet==0 ){
*pRc = SQLITE_NOMEM;
}
}
return zRet;
}
/*
** 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;
u32 iVal;
fts5FastGetVarint32(a, i, iVal);
if( iVal<=1 ){
if( iVal==0 ){
*pi = i;
return 0;
}
fts5FastGetVarint32(a, i, iVal);
iOff = ((i64)iVal) << 32;
assert( iOff>=0 );
fts5FastGetVarint32(a, i, iVal);
if( iVal<2 ){
/* This is a corrupt record. So stop parsing it here. */
*piOff = -1;
return 1;
}
*piOff = iOff + ((iVal-2) & 0x7FFFFFFF);
}else{
*piOff = (iOff & (i64)0x7FFFFFFF<<32)+((iOff + (iVal-2)) & 0x7FFFFFFF);
}
*pi = i;
assert_nc( *piOff>=iOff );
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->bEof = 1;
}
return pIter->bEof;
}
int sqlite3Fts5PoslistReaderInit(
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;
sqlite3Fts5PoslistReaderNext(pIter);
return pIter->bEof;
}
/*
** Append position iPos to the position list being accumulated in buffer
** pBuf, which must be already be large enough to hold the new data.
** The previous position written to this list is *piPrev. *piPrev is set
** to iPos before returning.
*/
void sqlite3Fts5PoslistSafeAppend(
Fts5Buffer *pBuf,
i64 *piPrev,
i64 iPos
){
if( iPos>=*piPrev ){
static const i64 colmask = ((i64)(0x7FFFFFFF)) << 32;
if( (iPos & colmask) != (*piPrev & colmask) ){
pBuf->p[pBuf->n++] = 1;
pBuf->n += sqlite3Fts5PutVarint(&pBuf->p[pBuf->n], (iPos>>32));
*piPrev = (iPos & colmask);
}
pBuf->n += sqlite3Fts5PutVarint(&pBuf->p[pBuf->n], (iPos-*piPrev)+2);
*piPrev = iPos;
}
}
int sqlite3Fts5PoslistWriterAppend(
Fts5Buffer *pBuf,
Fts5PoslistWriter *pWriter,
i64 iPos
){
int rc = 0; /* Initialized only to suppress erroneous warning from Clang */
if( fts5BufferGrow(&rc, pBuf, 5+5+5) ) return rc;
sqlite3Fts5PoslistSafeAppend(pBuf, &pWriter->iPrev, iPos);
return SQLITE_OK;
}
void *sqlite3Fts5MallocZero(int *pRc, sqlite3_int64 nByte){
void *pRet = 0;
if( *pRc==SQLITE_OK ){
pRet = sqlite3_malloc64(nByte);
if( pRet==0 ){
if( nByte>0 ) *pRc = SQLITE_NOMEM;
}else{
memset(pRet, 0, (size_t)nByte);
}
}
return pRet;
}
/*
** Return a nul-terminated copy of the string indicated by pIn. If nIn
** is non-negative, then it is the length of the string in bytes. Otherwise,
** the length of the string is determined using strlen().
**
** It is the responsibility of the caller to eventually free the returned
** buffer using sqlite3_free(). If an OOM error occurs, NULL is returned.
*/
char *sqlite3Fts5Strndup(int *pRc, const char *pIn, int nIn){
char *zRet = 0;
if( *pRc==SQLITE_OK ){
if( nIn<0 ){
nIn = (int)strlen(pIn);
}
zRet = (char*)sqlite3_malloc(nIn+1);
if( zRet ){
memcpy(zRet, pIn, nIn);
zRet[nIn] = '\0';
}else{
*pRc = SQLITE_NOMEM;
}
}
return zRet;
}
/*
** Return true if character 't' may be part of an FTS5 bareword, or false
** otherwise. Characters that may be part of barewords:
**
** * All non-ASCII characters,
** * The 52 upper and lower case ASCII characters, and
** * The 10 integer ASCII characters.
** * The underscore character "_" (0x5F).
** * The unicode "subsitute" character (0x1A).
*/
int sqlite3Fts5IsBareword(char t){
u8 aBareword[128] = {
0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, /* 0x00 .. 0x0F */
0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1, 0, 0, 0, 0, 0, /* 0x10 .. 0x1F */
0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, /* 0x20 .. 0x2F */
1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 0, 0, 0, 0, 0, 0, /* 0x30 .. 0x3F */
0, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, /* 0x40 .. 0x4F */
1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 0, 0, 0, 0, 1, /* 0x50 .. 0x5F */
0, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, /* 0x60 .. 0x6F */
1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 0, 0, 0, 0, 0 /* 0x70 .. 0x7F */
};
return (t & 0x80) || aBareword[(int)t];
}
/*************************************************************************
*/
typedef struct Fts5TermsetEntry Fts5TermsetEntry;
struct Fts5TermsetEntry {
char *pTerm;
int nTerm;
int iIdx; /* Index (main or aPrefix[] entry) */
Fts5TermsetEntry *pNext;
};
struct Fts5Termset {
Fts5TermsetEntry *apHash[512];
};
int sqlite3Fts5TermsetNew(Fts5Termset **pp){
int rc = SQLITE_OK;
*pp = sqlite3Fts5MallocZero(&rc, sizeof(Fts5Termset));
return rc;
}
int sqlite3Fts5TermsetAdd(
Fts5Termset *p,
int iIdx,
const char *pTerm, int nTerm,
int *pbPresent
){
int rc = SQLITE_OK;
*pbPresent = 0;
if( p ){
int i;
u32 hash = 13;
Fts5TermsetEntry *pEntry;
/* Calculate a hash value for this term. This is the same hash checksum
** used by the fts5_hash.c module. This is not important for correct
** operation of the module, but is necessary to ensure that some tests
** designed to produce hash table collisions really do work. */
for(i=nTerm-1; i>=0; i--){
hash = (hash << 3) ^ hash ^ pTerm[i];
}
hash = (hash << 3) ^ hash ^ iIdx;
hash = hash % ArraySize(p->apHash);
for(pEntry=p->apHash[hash]; pEntry; pEntry=pEntry->pNext){
if( pEntry->iIdx==iIdx
&& pEntry->nTerm==nTerm
&& memcmp(pEntry->pTerm, pTerm, nTerm)==0
){
*pbPresent = 1;
break;
}
}
if( pEntry==0 ){
pEntry = sqlite3Fts5MallocZero(&rc, sizeof(Fts5TermsetEntry) + nTerm);
if( pEntry ){
pEntry->pTerm = (char*)&pEntry[1];
pEntry->nTerm = nTerm;
pEntry->iIdx = iIdx;
memcpy(pEntry->pTerm, pTerm, nTerm);
pEntry->pNext = p->apHash[hash];
p->apHash[hash] = pEntry;
}
}
}
return rc;
}
void sqlite3Fts5TermsetFree(Fts5Termset *p){
if( p ){
u32 i;
for(i=0; i<ArraySize(p->apHash); i++){
Fts5TermsetEntry *pEntry = p->apHash[i];
while( pEntry ){
Fts5TermsetEntry *pDel = pEntry;
pEntry = pEntry->pNext;
sqlite3_free(pDel);
}
}
sqlite3_free(p);
}
}