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Fixes to the version of "varsep" group_concat so that (1) it builds under

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separate compilation and (2) omits tabs in source code and (3) runs faster
than trunk.  This variant of the group_concat_varsep branch might be preferred
over the tip because it preserves (undocumented) legacy behavior about the
position of separators relative to terms.

FossilOrigin-Name: 04399cf9645e04b171090ff8a3c27752929c10d2cd8778e26f8f3337aa902ab6
This commit is contained in:
drh
2021-10-01 00:25:06 +00:00
parent 34896c6855
commit f06db3e892
5 changed files with 75 additions and 57 deletions
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94
src/func.c
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@@ -1715,17 +1715,23 @@ static void minMaxFinalize(sqlite3_context *context){
/*
** group_concat(EXPR, ?SEPARATOR?)
**
** The SEPARATOR goes before the EXPR string. This is tragic. The
** groupConcatInverse() implementation would have been easier if the
** SEPARATOR were appended after EXPR. And the order is undocumented,
** so we could change it, in theory. But the old behavior has been
** around for so long that we dare not, for fear of breaking something.
*/
typedef struct {
StrAccum str; /* The accumulated concatenation */
#ifndef SQLITE_OMIT_WINDOWFUNC
int nAccum; /* Number of strings presently concatenated */
int nFirstSepLength; /* Used to detect separator length change */
int nFirstSepLength; /* Used to detect separator length change */
/* If pnSepLengths!=0, refs an array of inter-string separator lengths,
* stored as actually incorporated into presently accumulated result.
* (Hence, its slots in use number nAccum-1 between method calls.)
* If pnSepLengths==0, nFirstSepLength is the length used throughout.
*/
** stored as actually incorporated into presently accumulated result.
** (Hence, its slots in use number nAccum-1 between method calls.)
** If pnSepLengths==0, nFirstSepLength is the length used throughout.
*/
int *pnSepLengths;
#endif
} GroupConcatCtx;
@@ -1746,38 +1752,45 @@ static void groupConcatStep(
sqlite3 *db = sqlite3_context_db_handle(context);
int firstTerm = pGCC->str.mxAlloc==0;
pGCC->str.mxAlloc = db->aLimit[SQLITE_LIMIT_LENGTH];
if( !firstTerm ){
if( argc==2 ){
zSep = (char*)sqlite3_value_text(argv[1]);
nSep = sqlite3_value_bytes(argv[1]);
}else{
zSep = ",";
nSep = 1;
if( argc==1 ){
if( !firstTerm ){
sqlite3_str_appendchar(&pGCC->str, 1, ',');
}
if( zSep )
sqlite3_str_append(&pGCC->str, zSep, nSep);
#ifndef SQLITE_OMIT_WINDOWFUNC
else
nSep = 0;
else{
pGCC->nFirstSepLength = 1;
}
#endif
}else if( !firstTerm ){
zSep = (char*)sqlite3_value_text(argv[1]);
nSep = sqlite3_value_bytes(argv[1]);
if( zSep ){
sqlite3_str_append(&pGCC->str, zSep, nSep);
}
#ifndef SQLITE_OMIT_WINDOWFUNC
else{
nSep = 0;
}
if( nSep != pGCC->nFirstSepLength || pGCC->pnSepLengths != 0 ){
int * pnsl = pGCC->pnSepLengths;
if( pnsl == 0 ){
/* First separator length variation seen, start tracking them. */
pnsl = (int*)sqlite3_malloc64((pGCC->nAccum+1) * sizeof(int));
if( pnsl!=0 ){
int i = 0, nA = pGCC->nAccum-1;
while( i<nA ) pnsl[i++] = pGCC->nFirstSepLength;
}
}else{
pnsl = (int*)sqlite3_realloc64(pnsl, pGCC->nAccum * sizeof(int));
}
if( pnsl!=0 ){
if( pGCC->nAccum>0 )
pnsl[pGCC->nAccum-1] = nSep;
pGCC->pnSepLengths = pnsl;
}else{
setStrAccumError(&pGCC->str, SQLITE_NOMEM);
}
int *pnsl = pGCC->pnSepLengths;
if( pnsl == 0 ){
/* First separator length variation seen, start tracking them. */
pnsl = (int*)sqlite3_malloc64((pGCC->nAccum+1) * sizeof(int));
if( pnsl!=0 ){
int i = 0, nA = pGCC->nAccum-1;
while( i<nA ) pnsl[i++] = pGCC->nFirstSepLength;
}
}else{
pnsl = (int*)sqlite3_realloc64(pnsl, pGCC->nAccum * sizeof(int));
}
if( pnsl!=0 ){
if( pGCC->nAccum>0 ){
pnsl[pGCC->nAccum-1] = nSep;
}
pGCC->pnSepLengths = pnsl;
}else{
sqlite3StrAccumSetError(&pGCC->str, SQLITE_NOMEM);
}
}
#endif
}
@@ -1811,9 +1824,9 @@ static void groupConcatInverse(
if( pGCC->pnSepLengths!=0 ){
assert(pGCC->nAccum >= 0);
if( pGCC->nAccum>0 ){
nVS += *pGCC->pnSepLengths;
memmove(pGCC->pnSepLengths, pGCC->pnSepLengths+1,
(pGCC->nAccum-1)*sizeof(int));
nVS += *pGCC->pnSepLengths;
memmove(pGCC->pnSepLengths, pGCC->pnSepLengths+1,
(pGCC->nAccum-1)*sizeof(int));
}
}else{
/* If removing single accumulated string, harmlessly over-do. */
@@ -1844,8 +1857,9 @@ static void groupConcatFinalize(sqlite3_context *context){
sqlite3_result_error_toobig(context);
}else if( pAccum->accError==SQLITE_NOMEM ){
sqlite3_result_error_nomem(context);
}else{
sqlite3_result_text(context, sqlite3StrAccumFinish(pAccum), -1,
}else{
int n = pAccum->nChar;
sqlite3_result_text(context, sqlite3StrAccumFinish(pAccum), n,
sqlite3_free);
}
#ifndef SQLITE_OMIT_WINDOWFUNC
@@ -1865,7 +1879,7 @@ static void groupConcatValue(sqlite3_context *context){
sqlite3_result_error_nomem(context);
}else{
const char *zText = sqlite3_str_value(pAccum);
sqlite3_result_text(context, zText, -1, SQLITE_TRANSIENT);
sqlite3_result_text(context, zText, pAccum->nChar, SQLITE_TRANSIENT);
}
}
}