postgresql/contrib/tsearch2/query_rewrite.c
2006-05-31 14:53:41 +00:00

550 lines
11 KiB
C

#include "postgres.h"
#include "executor/spi.h"
#include "query_util.h"
MemoryContext AggregateContext = NULL;
static int
addone(int *counters, int last, int total)
{
counters[last]++;
if (counters[last] >= total)
{
if (last == 0)
return 0;
if (addone(counters, last - 1, total - 1) == 0)
return 0;
counters[last] = counters[last - 1] + 1;
}
return 1;
}
static QTNode *
findeq(QTNode * node, QTNode * ex, MemoryType memtype, QTNode * subs, bool *isfind)
{
if ((node->sign & ex->sign) != ex->sign || node->valnode->type != ex->valnode->type || node->valnode->val != ex->valnode->val)
return node;
if (node->flags & QTN_NOCHANGE)
return node;
if (node->valnode->type == OPR)
{
if (node->nchild == ex->nchild)
{
if (QTNEq(node, ex))
{
QTNFree(node);
if (subs)
{
node = QTNCopy(subs, memtype);
node->flags |= QTN_NOCHANGE;
}
else
node = NULL;
*isfind = true;
}
}
else if (node->nchild > ex->nchild)
{
int *counters = (int *) palloc(sizeof(int) * node->nchild);
int i;
QTNode *tnode = (QTNode *) MEMALLOC(memtype, sizeof(QTNode));
memset(tnode, 0, sizeof(QTNode));
tnode->child = (QTNode **) MEMALLOC(memtype, sizeof(QTNode *) * ex->nchild);
tnode->nchild = ex->nchild;
tnode->valnode = (ITEM *) MEMALLOC(memtype, sizeof(ITEM));
*(tnode->valnode) = *(ex->valnode);
for (i = 0; i < ex->nchild; i++)
counters[i] = i;
do
{
tnode->sign = 0;
for (i = 0; i < ex->nchild; i++)
{
tnode->child[i] = node->child[counters[i]];
tnode->sign |= tnode->child[i]->sign;
}
if (QTNEq(tnode, ex))
{
int j = 0;
MEMFREE(memtype, tnode->valnode);
MEMFREE(memtype, tnode->child);
MEMFREE(memtype, tnode);
if (subs)
{
tnode = QTNCopy(subs, memtype);
tnode->flags = QTN_NOCHANGE | QTN_NEEDFREE;
}
else
tnode = NULL;
node->child[counters[0]] = tnode;
for (i = 1; i < ex->nchild; i++)
node->child[counters[i]] = NULL;
for (i = 0; i < node->nchild; i++)
{
if (node->child[i])
{
node->child[j] = node->child[i];
j++;
}
}
node->nchild = j;
*isfind = true;
break;
}
} while (addone(counters, ex->nchild - 1, node->nchild));
if (tnode && (tnode->flags & QTN_NOCHANGE) == 0)
{
MEMFREE(memtype, tnode->valnode);
MEMFREE(memtype, tnode->child);
MEMFREE(memtype, tnode);
}
else
QTNSort(node);
pfree(counters);
}
}
else if (QTNEq(node, ex))
{
QTNFree(node);
if (subs)
{
node = QTNCopy(subs, memtype);
node->flags |= QTN_NOCHANGE;
}
else
{
node = NULL;
}
*isfind = true;
}
return node;
}
static QTNode *
dofindsubquery(QTNode * root, QTNode * ex, MemoryType memtype, QTNode * subs, bool *isfind)
{
root = findeq(root, ex, memtype, subs, isfind);
if (root && (root->flags & QTN_NOCHANGE) == 0 && root->valnode->type == OPR)
{
int i;
for (i = 0; i < root->nchild; i++)
root->child[i] = dofindsubquery(root->child[i], ex, memtype, subs, isfind);
}
return root;
}
static QTNode *
dropvoidsubtree(QTNode * root)
{
if (!root)
return NULL;
if (root->valnode->type == OPR)
{
int i,
j = 0;
for (i = 0; i < root->nchild; i++)
{
if (root->child[i])
{
root->child[j] = root->child[i];
j++;
}
}
root->nchild = j;
if (root->valnode->val == (int4) '!' && root->nchild == 0)
{
QTNFree(root);
root = NULL;
}
else if (root->nchild == 1)
{
QTNode *nroot = root->child[0];
pfree(root);
root = nroot;
}
}
return root;
}
static QTNode *
findsubquery(QTNode * root, QTNode * ex, MemoryType memtype, QTNode * subs, bool *isfind)
{
bool DidFind = false;
root = dofindsubquery(root, ex, memtype, subs, &DidFind);
if (!subs && DidFind)
root = dropvoidsubtree(root);
if (isfind)
*isfind = DidFind;
return root;
}
static Oid tsqOid = InvalidOid;
static void
get_tsq_Oid(void)
{
int ret;
bool isnull;
if ((ret = SPI_exec("select oid from pg_type where typname='tsquery'", 1)) < 0)
/* internal error */
elog(ERROR, "SPI_exec to get tsquery oid returns %d", ret);
if (SPI_processed < 1)
/* internal error */
elog(ERROR, "there is no tsvector type");
tsqOid = DatumGetObjectId(SPI_getbinval(SPI_tuptable->vals[0], SPI_tuptable->tupdesc, 1, &isnull));
if (tsqOid == InvalidOid)
/* internal error */
elog(ERROR, "tsquery type has InvalidOid");
}
PG_FUNCTION_INFO_V1(tsquery_rewrite);
PG_FUNCTION_INFO_V1(rewrite_accum);
Datum rewrite_accum(PG_FUNCTION_ARGS);
Datum
rewrite_accum(PG_FUNCTION_ARGS)
{
QUERYTYPE *acc = (QUERYTYPE *) PG_GETARG_POINTER(0);
ArrayType *qa = (ArrayType *) DatumGetPointer(PG_DETOAST_DATUM_COPY(PG_GETARG_DATUM(1)));
QUERYTYPE *q;
QTNode *qex,
*subs = NULL,
*acctree;
bool isfind = false;
Datum *elemsp;
int nelemsp;
AggregateContext = ((AggState *) fcinfo->context)->aggcontext;
if (acc == NULL || PG_ARGISNULL(0))
{
acc = (QUERYTYPE *) MEMALLOC(AggMemory, sizeof(QUERYTYPE));
acc->len = HDRSIZEQT;
acc->size = 0;
}
if (qa == NULL || PG_ARGISNULL(1))
{
PG_FREE_IF_COPY(qa, 1);
PG_RETURN_POINTER(acc);
}
if (ARR_NDIM(qa) != 1)
elog(ERROR, "array must be one-dimensional, not %d dimension", ARR_NDIM(qa));
if (ArrayGetNItems(ARR_NDIM(qa), ARR_DIMS(qa)) != 3)
elog(ERROR, "array should have only three elements");
if (tsqOid == InvalidOid)
{
SPI_connect();
get_tsq_Oid();
SPI_finish();
}
if (ARR_ELEMTYPE(qa) != tsqOid)
elog(ERROR, "array should contain tsquery type");
deconstruct_array(qa, tsqOid, -1, false, 'i', &elemsp, NULL, &nelemsp);
q = (QUERYTYPE *) DatumGetPointer(elemsp[0]);
if (q->size == 0)
{
pfree(elemsp);
PG_RETURN_POINTER(acc);
}
if (!acc->size)
{
if (acc->len > HDRSIZEQT)
{
pfree(elemsp);
PG_RETURN_POINTER(acc);
}
else
acctree = QT2QTN(GETQUERY(q), GETOPERAND(q));
}
else
acctree = QT2QTN(GETQUERY(acc), GETOPERAND(acc));
QTNTernary(acctree);
QTNSort(acctree);
q = (QUERYTYPE *) DatumGetPointer(elemsp[1]);
if (q->size == 0)
{
pfree(elemsp);
PG_RETURN_POINTER(acc);
}
qex = QT2QTN(GETQUERY(q), GETOPERAND(q));
QTNTernary(qex);
QTNSort(qex);
q = (QUERYTYPE *) DatumGetPointer(elemsp[2]);
if (q->size)
subs = QT2QTN(GETQUERY(q), GETOPERAND(q));
acctree = findsubquery(acctree, qex, PlainMemory, subs, &isfind);
if (isfind || !acc->size)
{
/* pfree( acc ); do not pfree(p), because nodeAgg.c will */
if (acctree)
{
QTNBinary(acctree);
acc = QTN2QT(acctree, AggMemory);
}
else
{
acc = (QUERYTYPE *) MEMALLOC(AggMemory, HDRSIZEQT * 2);
acc->len = HDRSIZEQT * 2;
acc->size = 0;
}
}
pfree(elemsp);
QTNFree(qex);
QTNFree(subs);
QTNFree(acctree);
PG_RETURN_POINTER(acc);
}
PG_FUNCTION_INFO_V1(rewrite_finish);
Datum rewrite_finish(PG_FUNCTION_ARGS);
Datum
rewrite_finish(PG_FUNCTION_ARGS)
{
QUERYTYPE *acc = (QUERYTYPE *) PG_GETARG_POINTER(0);
QUERYTYPE *rewrited;
if (acc == NULL || PG_ARGISNULL(0) || acc->size == 0)
{
acc = (QUERYTYPE *) palloc(sizeof(QUERYTYPE));
acc->len = HDRSIZEQT;
acc->size = 0;
}
rewrited = (QUERYTYPE *) palloc(acc->len);
memcpy(rewrited, acc, acc->len);
pfree(acc);
PG_RETURN_POINTER(rewrited);
}
Datum tsquery_rewrite(PG_FUNCTION_ARGS);
Datum
tsquery_rewrite(PG_FUNCTION_ARGS)
{
QUERYTYPE *query = (QUERYTYPE *) DatumGetPointer(PG_DETOAST_DATUM_COPY(PG_GETARG_DATUM(0)));
text *in = PG_GETARG_TEXT_P(1);
QUERYTYPE *rewrited = query;
QTNode *tree;
char *buf;
void *plan;
Portal portal;
bool isnull;
int i;
if (query->size == 0)
{
PG_FREE_IF_COPY(in, 1);
PG_RETURN_POINTER(rewrited);
}
tree = QT2QTN(GETQUERY(query), GETOPERAND(query));
QTNTernary(tree);
QTNSort(tree);
buf = (char *) palloc(VARSIZE(in));
memcpy(buf, VARDATA(in), VARSIZE(in) - VARHDRSZ);
buf[VARSIZE(in) - VARHDRSZ] = '\0';
SPI_connect();
if (tsqOid == InvalidOid)
get_tsq_Oid();
if ((plan = SPI_prepare(buf, 0, NULL)) == NULL)
elog(ERROR, "SPI_prepare('%s') returns NULL", buf);
if ((portal = SPI_cursor_open(NULL, plan, NULL, NULL, false)) == NULL)
elog(ERROR, "SPI_cursor_open('%s') returns NULL", buf);
SPI_cursor_fetch(portal, true, 100);
if (SPI_tuptable->tupdesc->natts != 2)
elog(ERROR, "number of fields doesn't equal to 2");
if (SPI_gettypeid(SPI_tuptable->tupdesc, 1) != tsqOid)
elog(ERROR, "column #1 isn't of tsquery type");
if (SPI_gettypeid(SPI_tuptable->tupdesc, 2) != tsqOid)
elog(ERROR, "column #2 isn't of tsquery type");
while (SPI_processed > 0 && tree)
{
for (i = 0; i < SPI_processed && tree; i++)
{
Datum qdata = SPI_getbinval(SPI_tuptable->vals[i], SPI_tuptable->tupdesc, 1, &isnull);
Datum sdata;
if (isnull)
continue;
sdata = SPI_getbinval(SPI_tuptable->vals[i], SPI_tuptable->tupdesc, 2, &isnull);
if (!isnull)
{
QUERYTYPE *qtex = (QUERYTYPE *) DatumGetPointer(PG_DETOAST_DATUM(qdata));
QUERYTYPE *qtsubs = (QUERYTYPE *) DatumGetPointer(PG_DETOAST_DATUM(sdata));
QTNode *qex,
*qsubs = NULL;
if (qtex->size == 0)
{
if (qtex != (QUERYTYPE *) DatumGetPointer(qdata))
pfree(qtex);
if (qtsubs != (QUERYTYPE *) DatumGetPointer(sdata))
pfree(qtsubs);
continue;
}
qex = QT2QTN(GETQUERY(qtex), GETOPERAND(qtex));
QTNTernary(qex);
QTNSort(qex);
if (qtsubs->size)
qsubs = QT2QTN(GETQUERY(qtsubs), GETOPERAND(qtsubs));
tree = findsubquery(tree, qex, SPIMemory, qsubs, NULL);
QTNFree(qex);
if (qtex != (QUERYTYPE *) DatumGetPointer(qdata))
pfree(qtex);
QTNFree(qsubs);
if (qtsubs != (QUERYTYPE *) DatumGetPointer(sdata))
pfree(qtsubs);
}
}
SPI_freetuptable(SPI_tuptable);
SPI_cursor_fetch(portal, true, 100);
}
SPI_freetuptable(SPI_tuptable);
SPI_cursor_close(portal);
SPI_freeplan(plan);
SPI_finish();
if (tree)
{
QTNBinary(tree);
rewrited = QTN2QT(tree, PlainMemory);
QTNFree(tree);
PG_FREE_IF_COPY(query, 0);
}
else
{
rewrited->len = HDRSIZEQT;
rewrited->size = 0;
}
pfree(buf);
PG_FREE_IF_COPY(in, 1);
PG_RETURN_POINTER(rewrited);
}
PG_FUNCTION_INFO_V1(tsquery_rewrite_query);
Datum tsquery_rewrite_query(PG_FUNCTION_ARGS);
Datum
tsquery_rewrite_query(PG_FUNCTION_ARGS)
{
QUERYTYPE *query = (QUERYTYPE *) DatumGetPointer(PG_DETOAST_DATUM_COPY(PG_GETARG_DATUM(0)));
QUERYTYPE *ex = (QUERYTYPE *) DatumGetPointer(PG_DETOAST_DATUM(PG_GETARG_DATUM(1)));
QUERYTYPE *subst = (QUERYTYPE *) DatumGetPointer(PG_DETOAST_DATUM(PG_GETARG_DATUM(2)));
QUERYTYPE *rewrited = query;
QTNode *tree,
*qex,
*subs = NULL;
if (query->size == 0 || ex->size == 0)
{
PG_FREE_IF_COPY(ex, 1);
PG_FREE_IF_COPY(subst, 2);
PG_RETURN_POINTER(rewrited);
}
tree = QT2QTN(GETQUERY(query), GETOPERAND(query));
QTNTernary(tree);
QTNSort(tree);
qex = QT2QTN(GETQUERY(ex), GETOPERAND(ex));
QTNTernary(qex);
QTNSort(qex);
if (subst->size)
subs = QT2QTN(GETQUERY(subst), GETOPERAND(subst));
tree = findsubquery(tree, qex, PlainMemory, subs, NULL);
QTNFree(qex);
QTNFree(subs);
if (!tree)
{
rewrited->len = HDRSIZEQT;
rewrited->size = 0;
PG_FREE_IF_COPY(ex, 1);
PG_FREE_IF_COPY(subst, 2);
PG_RETURN_POINTER(rewrited);
}
else
{
QTNBinary(tree);
rewrited = QTN2QT(tree, PlainMemory);
QTNFree(tree);
}
PG_FREE_IF_COPY(query, 0);
PG_FREE_IF_COPY(ex, 1);
PG_FREE_IF_COPY(subst, 2);
PG_RETURN_POINTER(rewrited);
}