diff options
Diffstat (limited to 'src/backend/utils/adt/tsquery_util.c')
| -rw-r--r-- | src/backend/utils/adt/tsquery_util.c | 82 |
1 files changed, 59 insertions, 23 deletions
diff --git a/src/backend/utils/adt/tsquery_util.c b/src/backend/utils/adt/tsquery_util.c index 0f338aa653d..9add11f6574 100644 --- a/src/backend/utils/adt/tsquery_util.c +++ b/src/backend/utils/adt/tsquery_util.c @@ -17,6 +17,9 @@ #include "tsearch/ts_utils.h" #include "miscadmin.h" +/* + * Build QTNode tree for a tsquery given in QueryItem array format. + */ QTNode * QT2QTN(QueryItem *in, char *operand) { @@ -50,6 +53,12 @@ QT2QTN(QueryItem *in, char *operand) return node; } +/* + * Free a QTNode tree. + * + * Referenced "word" and "valnode" items are freed if marked as transient + * by flags. + */ void QTNFree(QTNode *in) { @@ -62,26 +71,27 @@ QTNFree(QTNode *in) if (in->valnode->type == QI_VAL && in->word && (in->flags & QTN_WORDFREE) != 0) pfree(in->word); - if (in->child) + if (in->valnode->type == QI_OPR) { - if (in->valnode) - { - if (in->valnode->type == QI_OPR && in->nchild > 0) - { - int i; - - for (i = 0; i < in->nchild; i++) - QTNFree(in->child[i]); - } - if (in->flags & QTN_NEEDFREE) - pfree(in->valnode); - } - pfree(in->child); + int i; + + for (i = 0; i < in->nchild; i++) + QTNFree(in->child[i]); } + if (in->child) + pfree(in->child); + + if (in->flags & QTN_NEEDFREE) + pfree(in->valnode); pfree(in); } +/* + * Sort comparator for QTNodes. + * + * The sort order is somewhat arbitrary. + */ int QTNodeCompare(QTNode *an, QTNode *bn) { @@ -135,12 +145,19 @@ QTNodeCompare(QTNode *an, QTNode *bn) } } +/* + * qsort comparator for QTNode pointers. + */ static int cmpQTN(const void *a, const void *b) { return QTNodeCompare(*(QTNode *const *) a, *(QTNode *const *) b); } +/* + * Canonicalize a QTNode tree by sorting the children of AND/OR nodes + * into an arbitrary but well-defined order. + */ void QTNSort(QTNode *in) { @@ -158,13 +175,16 @@ QTNSort(QTNode *in) qsort((void *) in->child, in->nchild, sizeof(QTNode *), cmpQTN); } +/* + * Are two QTNode trees equal according to QTNodeCompare? + */ bool QTNEq(QTNode *a, QTNode *b) { uint32 sign = a->sign & b->sign; if (!(sign == a->sign && sign == b->sign)) - return 0; + return false; return (QTNodeCompare(a, b) == 0) ? true : false; } @@ -190,14 +210,17 @@ QTNTernary(QTNode *in) for (i = 0; i < in->nchild; i++) QTNTernary(in->child[i]); + /* Only AND and OR are associative, so don't flatten other node types */ + if (in->valnode->qoperator.oper != OP_AND && + in->valnode->qoperator.oper != OP_OR) + return; + for (i = 0; i < in->nchild; i++) { QTNode *cc = in->child[i]; - /* OP_Phrase isn't associative */ if (cc->valnode->type == QI_OPR && - in->valnode->qoperator.oper == cc->valnode->qoperator.oper && - in->valnode->qoperator.oper != OP_PHRASE) + in->valnode->qoperator.oper == cc->valnode->qoperator.oper) { int oldnchild = in->nchild; @@ -236,9 +259,6 @@ QTNBinary(QTNode *in) for (i = 0; i < in->nchild; i++) QTNBinary(in->child[i]); - if (in->nchild <= 2) - return; - while (in->nchild > 2) { QTNode *nn = (QTNode *) palloc0(sizeof(QTNode)); @@ -263,8 +283,9 @@ QTNBinary(QTNode *in) } /* - * Count the total length of operand string in tree, including '\0'- - * terminators. + * Count the total length of operand strings in tree (including '\0'- + * terminators) and the total number of nodes. + * Caller must initialize *sumlen and *nnode to zeroes. */ static void cntsize(QTNode *in, int *sumlen, int *nnode) @@ -293,6 +314,10 @@ typedef struct char *curoperand; } QTN2QTState; +/* + * Recursively convert a QTNode tree into flat tsquery format. + * Caller must have allocated arrays of the correct size. + */ static void fillQT(QTN2QTState *state, QTNode *in) { @@ -330,6 +355,9 @@ fillQT(QTN2QTState *state, QTNode *in) } } +/* + * Build flat tsquery from a QTNode tree. + */ TSQuery QTN2QT(QTNode *in) { @@ -358,6 +386,11 @@ QTN2QT(QTNode *in) return out; } +/* + * Copy a QTNode tree. + * + * Modifiable copies of the words and valnodes are made, too. + */ QTNode * QTNCopy(QTNode *in) { @@ -393,6 +426,9 @@ QTNCopy(QTNode *in) return out; } +/* + * Clear the specified flag bit(s) in all nodes of a QTNode tree. + */ void QTNClearFlags(QTNode *in, uint32 flags) { |