Tsearch2 functionality migrates to core. The bulk of this work is by

Oleg Bartunov and Teodor Sigaev, but I did a lot of editorializing,
so anything that's broken is probably my fault.

Documentation is nonexistent as yet, but let's land the patch so we can
get some portability testing done.

1 files changed, 524 insertions, 0 deletions

diff --git a/src/backend/utils/adt/tsquery_rewrite.c b/src/backend/utils/adt/tsquery_rewrite.c
new file mode 100644
index 00000000000..f0d22c644ae
--- /dev/null
+++ b/src/backend/utils/adt/tsquery_rewrite.c
@@ -0,0 +1,524 @@
+/*-------------------------------------------------------------------------
+ *
+ * tsquery_rewrite.c
+ *	  Utilities for reconstructing tsquery
+ *
+ * Portions Copyright (c) 1996-2007, PostgreSQL Global Development Group
+ *
+ *
+ * IDENTIFICATION
+ *	  $PostgreSQL: pgsql/src/backend/utils/adt/tsquery_rewrite.c,v 1.1 2007/08/21 01:11:19 tgl Exp $
+ *
+ *-------------------------------------------------------------------------
+ */
+
+#include "postgres.h"
+
+#include "executor/spi.h"
+#include "tsearch/ts_type.h"
+#include "tsearch/ts_utils.h"
+
+
+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, 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);
+					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 *) palloc(sizeof(QTNode));
+
+			memset(tnode, 0, sizeof(QTNode));
+			tnode->child = (QTNode **) palloc(sizeof(QTNode *) * ex->nchild);
+			tnode->nchild = ex->nchild;
+			tnode->valnode = (QueryItem *) palloc(sizeof(QueryItem));
+			*(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;
+
+					pfree(tnode->valnode);
+					pfree(tnode->child);
+					pfree(tnode);
+					if (subs)
+					{
+						tnode = QTNCopy(subs);
+						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)
+			{
+				pfree(tnode->valnode);
+				pfree(tnode->child);
+				pfree(tnode);
+			}
+			else
+				QTNSort(node);
+			pfree(counters);
+		}
+	}
+	else if (QTNEq(node, ex))
+	{
+		QTNFree(node);
+		if (subs)
+		{
+			node = QTNCopy(subs);
+			node->flags |= QTN_NOCHANGE;
+		}
+		else
+		{
+			node = NULL;
+		}
+		*isfind = true;
+	}
+
+	return node;
+}
+
+static QTNode *
+dofindsubquery(QTNode *root, QTNode *ex, QTNode *subs, bool *isfind)
+{
+	root = findeq(root, ex, 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, 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, QTNode *subs, bool *isfind)
+{
+	bool		DidFind = false;
+
+	root = dofindsubquery(root, ex, subs, &DidFind);
+
+	if (!subs && DidFind)
+		root = dropvoidsubtree(root);
+
+	if (isfind)
+		*isfind = DidFind;
+
+	return root;
+}
+
+Datum
+ts_rewrite_accum(PG_FUNCTION_ARGS)
+{
+	TSQuery		acc;
+	ArrayType  *qa;
+	TSQuery		q;
+	QTNode	   *qex = NULL,
+			   *subs = NULL,
+			   *acctree = NULL;
+	bool		isfind = false;
+	Datum	   *elemsp;
+	int			nelemsp;
+	MemoryContext aggcontext;
+	MemoryContext oldcontext;
+
+	aggcontext = ((AggState *) fcinfo->context)->aggcontext;
+
+	if (PG_ARGISNULL(0) || PG_GETARG_POINTER(0) == NULL)
+	{
+		acc = (TSQuery) MemoryContextAlloc(aggcontext, HDRSIZETQ);
+		SET_VARSIZE(acc, HDRSIZETQ);
+		acc->size = 0;
+	}
+	else
+		acc = PG_GETARG_TSQUERY(0);
+
+	if (PG_ARGISNULL(1) || PG_GETARG_POINTER(1) == NULL)
+		PG_RETURN_TSQUERY(acc);
+	else
+		qa = PG_GETARG_ARRAYTYPE_P_COPY(1);
+
+	if (ARR_NDIM(qa) != 1)
+		elog(ERROR, "array must be one-dimensional, not %d dimensions",
+			 ARR_NDIM(qa));
+	if (ArrayGetNItems(ARR_NDIM(qa), ARR_DIMS(qa)) != 3)
+		elog(ERROR, "array should have only three elements");
+	if (ARR_ELEMTYPE(qa) != TSQUERYOID)
+		elog(ERROR, "array should contain tsquery type");
+
+	deconstruct_array(qa, TSQUERYOID, -1, false, 'i', &elemsp, NULL, &nelemsp);
+
+	q = DatumGetTSQuery(elemsp[0]);
+	if (q->size == 0)
+	{
+		pfree(elemsp);
+		PG_RETURN_POINTER(acc);
+	}
+
+	if (!acc->size)
+	{
+		if (VARSIZE(acc) > HDRSIZETQ)
+		{
+			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 = DatumGetTSQuery(elemsp[1]);
+	if (q->size == 0)
+	{
+		pfree(elemsp);
+		PG_RETURN_POINTER(acc);
+	}
+	qex = QT2QTN(GETQUERY(q), GETOPERAND(q));
+	QTNTernary(qex);
+	QTNSort(qex);
+
+	q = DatumGetTSQuery(elemsp[2]);
+	if (q->size)
+		subs = QT2QTN(GETQUERY(q), GETOPERAND(q));
+
+	acctree = findsubquery(acctree, qex, subs, &isfind);
+
+	if (isfind || !acc->size)
+	{
+		/* pfree( acc ); do not pfree(p), because nodeAgg.c will */
+		if (acctree)
+		{
+			QTNBinary(acctree);
+			oldcontext = MemoryContextSwitchTo(aggcontext);
+			acc = QTN2QT(acctree);
+			MemoryContextSwitchTo(oldcontext);
+		}
+		else
+		{
+			acc = (TSQuery) MemoryContextAlloc(aggcontext, HDRSIZETQ);
+			SET_VARSIZE(acc, HDRSIZETQ);
+			acc->size = 0;
+		}
+	}
+
+	pfree(elemsp);
+	QTNFree(qex);
+	QTNFree(subs);
+	QTNFree(acctree);
+
+	PG_RETURN_TSQUERY(acc);
+}
+
+Datum
+ts_rewrite_finish(PG_FUNCTION_ARGS)
+{
+	TSQuery		acc = PG_GETARG_TSQUERY(0);
+	TSQuery		rewrited;
+
+	if (acc == NULL || PG_ARGISNULL(0) || acc->size == 0)
+	{
+		rewrited = (TSQuery) palloc(HDRSIZETQ);
+		SET_VARSIZE(rewrited, HDRSIZETQ);
+		rewrited->size = 0;
+	}
+	else
+	{
+		rewrited = (TSQuery) palloc(VARSIZE(acc));
+		memcpy(rewrited, acc, VARSIZE(acc));
+		pfree(acc);
+	}
+
+	PG_RETURN_POINTER(rewrited);
+}
+
+Datum
+tsquery_rewrite(PG_FUNCTION_ARGS)
+{
+	TSQuery		query = PG_GETARG_TSQUERY_COPY(0);
+	text	   *in = PG_GETARG_TEXT_P(1);
+	TSQuery		rewrited = query;
+	MemoryContext outercontext = CurrentMemoryContext;
+	MemoryContext oldcontext;
+	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 = TextPGetCString(in);
+
+	SPI_connect();
+
+	if ((plan = SPI_prepare(buf, 0, NULL)) == NULL)
+		elog(ERROR, "SPI_prepare(\"%s\") failed", buf);
+
+	if ((portal = SPI_cursor_open(NULL, plan, NULL, NULL, false)) == NULL)
+		elog(ERROR, "SPI_cursor_open(\"%s\") failed", buf);
+
+	SPI_cursor_fetch(portal, true, 100);
+
+	if (SPI_tuptable->tupdesc->natts != 2 ||
+		SPI_gettypeid(SPI_tuptable->tupdesc, 1) != TSQUERYOID ||
+		SPI_gettypeid(SPI_tuptable->tupdesc, 2) != TSQUERYOID)
+		ereport(ERROR,
+				(errcode(ERRCODE_INVALID_PARAMETER_VALUE),
+				 errmsg("ts_rewrite query must return two tsquery columns")));
+
+	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)
+			{
+				TSQuery		qtex = DatumGetTSQuery(qdata);
+				TSQuery		qtsubs = DatumGetTSQuery(sdata);
+				QTNode	   *qex,
+						   *qsubs = NULL;
+
+				if (qtex->size == 0)
+				{
+					if (qtex != (TSQuery) DatumGetPointer(qdata))
+						pfree(qtex);
+					if (qtsubs != (TSQuery) DatumGetPointer(sdata))
+						pfree(qtsubs);
+					continue;
+				}
+
+				qex = QT2QTN(GETQUERY(qtex), GETOPERAND(qtex));
+
+				QTNTernary(qex);
+				QTNSort(qex);
+
+				if (qtsubs->size)
+					qsubs = QT2QTN(GETQUERY(qtsubs), GETOPERAND(qtsubs));
+
+				oldcontext = MemoryContextSwitchTo(outercontext);
+				tree = findsubquery(tree, qex, qsubs, NULL);
+				MemoryContextSwitchTo(oldcontext);
+
+				QTNFree(qex);
+				if (qtex != (TSQuery) DatumGetPointer(qdata))
+					pfree(qtex);
+				QTNFree(qsubs);
+				if (qtsubs != (TSQuery) 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);
+		QTNFree(tree);
+		PG_FREE_IF_COPY(query, 0);
+	}
+	else
+	{
+		SET_VARSIZE(rewrited, HDRSIZETQ);
+		rewrited->size = 0;
+	}
+
+	pfree(buf);
+	PG_FREE_IF_COPY(in, 1);
+	PG_RETURN_POINTER(rewrited);
+}
+
+Datum
+tsquery_rewrite_query(PG_FUNCTION_ARGS)
+{
+	TSQuery		query = PG_GETARG_TSQUERY_COPY(0);
+	TSQuery		ex = PG_GETARG_TSQUERY(1);
+	TSQuery		subst = PG_GETARG_TSQUERY(2);
+	TSQuery		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, subs, NULL);
+	QTNFree(qex);
+	QTNFree(subs);
+
+	if (!tree)
+	{
+		SET_VARSIZE(rewrited, HDRSIZETQ);
+		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);
+		QTNFree(tree);
+	}
+
+	PG_FREE_IF_COPY(query, 0);
+	PG_FREE_IF_COPY(ex, 1);
+	PG_FREE_IF_COPY(subst, 2);
+	PG_RETURN_POINTER(rewrited);
+}