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Diffstat (limited to 'src/backend/utils/misc/queryjumble.c')
-rw-r--r-- | src/backend/utils/misc/queryjumble.c | 858 |
1 files changed, 858 insertions, 0 deletions
diff --git a/src/backend/utils/misc/queryjumble.c b/src/backend/utils/misc/queryjumble.c new file mode 100644 index 0000000..9f2cd1f --- /dev/null +++ b/src/backend/utils/misc/queryjumble.c @@ -0,0 +1,858 @@ +/*------------------------------------------------------------------------- + * + * queryjumble.c + * Query normalization and fingerprinting. + * + * Normalization is a process whereby similar queries, typically differing only + * in their constants (though the exact rules are somewhat more subtle than + * that) are recognized as equivalent, and are tracked as a single entry. This + * is particularly useful for non-prepared queries. + * + * Normalization is implemented by fingerprinting queries, selectively + * serializing those fields of each query tree's nodes that are judged to be + * essential to the query. This is referred to as a query jumble. This is + * distinct from a regular serialization in that various extraneous + * information is ignored as irrelevant or not essential to the query, such + * as the collations of Vars and, most notably, the values of constants. + * + * This jumble is acquired at the end of parse analysis of each query, and + * a 64-bit hash of it is stored into the query's Query.queryId field. + * The server then copies this value around, making it available in plan + * tree(s) generated from the query. The executor can then use this value + * to blame query costs on the proper queryId. + * + * Portions Copyright (c) 1996-2021, PostgreSQL Global Development Group + * Portions Copyright (c) 1994, Regents of the University of California + * + * + * IDENTIFICATION + * src/backend/utils/misc/queryjumble.c + * + *------------------------------------------------------------------------- + */ +#include "postgres.h" + +#include "common/hashfn.h" +#include "miscadmin.h" +#include "parser/scansup.h" +#include "utils/queryjumble.h" + +#define JUMBLE_SIZE 1024 /* query serialization buffer size */ + +/* GUC parameters */ +int compute_query_id = COMPUTE_QUERY_ID_AUTO; + +/* True when compute_query_id is ON, or AUTO and a module requests them */ +bool query_id_enabled = false; + +static uint64 compute_utility_query_id(const char *str, int query_location, int query_len); +static void AppendJumble(JumbleState *jstate, + const unsigned char *item, Size size); +static void JumbleQueryInternal(JumbleState *jstate, Query *query); +static void JumbleRangeTable(JumbleState *jstate, List *rtable); +static void JumbleRowMarks(JumbleState *jstate, List *rowMarks); +static void JumbleExpr(JumbleState *jstate, Node *node); +static void RecordConstLocation(JumbleState *jstate, int location); + +/* + * Given a possibly multi-statement source string, confine our attention to the + * relevant part of the string. + */ +const char * +CleanQuerytext(const char *query, int *location, int *len) +{ + int query_location = *location; + int query_len = *len; + + /* First apply starting offset, unless it's -1 (unknown). */ + if (query_location >= 0) + { + Assert(query_location <= strlen(query)); + query += query_location; + /* Length of 0 (or -1) means "rest of string" */ + if (query_len <= 0) + query_len = strlen(query); + else + Assert(query_len <= strlen(query)); + } + else + { + /* If query location is unknown, distrust query_len as well */ + query_location = 0; + query_len = strlen(query); + } + + /* + * Discard leading and trailing whitespace, too. Use scanner_isspace() + * not libc's isspace(), because we want to match the lexer's behavior. + */ + while (query_len > 0 && scanner_isspace(query[0])) + query++, query_location++, query_len--; + while (query_len > 0 && scanner_isspace(query[query_len - 1])) + query_len--; + + *location = query_location; + *len = query_len; + + return query; +} + +JumbleState * +JumbleQuery(Query *query, const char *querytext) +{ + JumbleState *jstate = NULL; + + Assert(IsQueryIdEnabled()); + + if (query->utilityStmt) + { + query->queryId = compute_utility_query_id(querytext, + query->stmt_location, + query->stmt_len); + } + else + { + jstate = (JumbleState *) palloc(sizeof(JumbleState)); + + /* Set up workspace for query jumbling */ + jstate->jumble = (unsigned char *) palloc(JUMBLE_SIZE); + jstate->jumble_len = 0; + jstate->clocations_buf_size = 32; + jstate->clocations = (LocationLen *) + palloc(jstate->clocations_buf_size * sizeof(LocationLen)); + jstate->clocations_count = 0; + jstate->highest_extern_param_id = 0; + + /* Compute query ID and mark the Query node with it */ + JumbleQueryInternal(jstate, query); + query->queryId = DatumGetUInt64(hash_any_extended(jstate->jumble, + jstate->jumble_len, + 0)); + + /* + * If we are unlucky enough to get a hash of zero, use 1 instead, to + * prevent confusion with the utility-statement case. + */ + if (query->queryId == UINT64CONST(0)) + query->queryId = UINT64CONST(1); + } + + return jstate; +} + +/* + * Enables query identifier computation. + * + * Third-party plugins can use this function to inform core that they require + * a query identifier to be computed. + */ +void +EnableQueryId(void) +{ + if (compute_query_id != COMPUTE_QUERY_ID_OFF) + query_id_enabled = true; +} + +/* + * Compute a query identifier for the given utility query string. + */ +static uint64 +compute_utility_query_id(const char *query_text, int query_location, int query_len) +{ + uint64 queryId; + const char *sql; + + /* + * Confine our attention to the relevant part of the string, if the query + * is a portion of a multi-statement source string. + */ + sql = CleanQuerytext(query_text, &query_location, &query_len); + + queryId = DatumGetUInt64(hash_any_extended((const unsigned char *) sql, + query_len, 0)); + + /* + * If we are unlucky enough to get a hash of zero(invalid), use queryID as + * 2 instead, queryID 1 is already in use for normal statements. + */ + if (queryId == UINT64CONST(0)) + queryId = UINT64CONST(2); + + return queryId; +} + +/* + * AppendJumble: Append a value that is substantive in a given query to + * the current jumble. + */ +static void +AppendJumble(JumbleState *jstate, const unsigned char *item, Size size) +{ + unsigned char *jumble = jstate->jumble; + Size jumble_len = jstate->jumble_len; + + /* + * Whenever the jumble buffer is full, we hash the current contents and + * reset the buffer to contain just that hash value, thus relying on the + * hash to summarize everything so far. + */ + while (size > 0) + { + Size part_size; + + if (jumble_len >= JUMBLE_SIZE) + { + uint64 start_hash; + + start_hash = DatumGetUInt64(hash_any_extended(jumble, + JUMBLE_SIZE, 0)); + memcpy(jumble, &start_hash, sizeof(start_hash)); + jumble_len = sizeof(start_hash); + } + part_size = Min(size, JUMBLE_SIZE - jumble_len); + memcpy(jumble + jumble_len, item, part_size); + jumble_len += part_size; + item += part_size; + size -= part_size; + } + jstate->jumble_len = jumble_len; +} + +/* + * Wrappers around AppendJumble to encapsulate details of serialization + * of individual local variable elements. + */ +#define APP_JUMB(item) \ + AppendJumble(jstate, (const unsigned char *) &(item), sizeof(item)) +#define APP_JUMB_STRING(str) \ + AppendJumble(jstate, (const unsigned char *) (str), strlen(str) + 1) + +/* + * JumbleQueryInternal: Selectively serialize the query tree, appending + * significant data to the "query jumble" while ignoring nonsignificant data. + * + * Rule of thumb for what to include is that we should ignore anything not + * semantically significant (such as alias names) as well as anything that can + * be deduced from child nodes (else we'd just be double-hashing that piece + * of information). + */ +static void +JumbleQueryInternal(JumbleState *jstate, Query *query) +{ + Assert(IsA(query, Query)); + Assert(query->utilityStmt == NULL); + + APP_JUMB(query->commandType); + /* resultRelation is usually predictable from commandType */ + JumbleExpr(jstate, (Node *) query->cteList); + JumbleRangeTable(jstate, query->rtable); + JumbleExpr(jstate, (Node *) query->jointree); + JumbleExpr(jstate, (Node *) query->targetList); + JumbleExpr(jstate, (Node *) query->onConflict); + JumbleExpr(jstate, (Node *) query->returningList); + JumbleExpr(jstate, (Node *) query->groupClause); + APP_JUMB(query->groupDistinct); + JumbleExpr(jstate, (Node *) query->groupingSets); + JumbleExpr(jstate, query->havingQual); + JumbleExpr(jstate, (Node *) query->windowClause); + JumbleExpr(jstate, (Node *) query->distinctClause); + JumbleExpr(jstate, (Node *) query->sortClause); + JumbleExpr(jstate, query->limitOffset); + JumbleExpr(jstate, query->limitCount); + APP_JUMB(query->limitOption); + JumbleRowMarks(jstate, query->rowMarks); + JumbleExpr(jstate, query->setOperations); +} + +/* + * Jumble a range table + */ +static void +JumbleRangeTable(JumbleState *jstate, List *rtable) +{ + ListCell *lc; + + foreach(lc, rtable) + { + RangeTblEntry *rte = lfirst_node(RangeTblEntry, lc); + + APP_JUMB(rte->rtekind); + switch (rte->rtekind) + { + case RTE_RELATION: + APP_JUMB(rte->relid); + JumbleExpr(jstate, (Node *) rte->tablesample); + APP_JUMB(rte->inh); + break; + case RTE_SUBQUERY: + JumbleQueryInternal(jstate, rte->subquery); + break; + case RTE_JOIN: + APP_JUMB(rte->jointype); + break; + case RTE_FUNCTION: + JumbleExpr(jstate, (Node *) rte->functions); + break; + case RTE_TABLEFUNC: + JumbleExpr(jstate, (Node *) rte->tablefunc); + break; + case RTE_VALUES: + JumbleExpr(jstate, (Node *) rte->values_lists); + break; + case RTE_CTE: + + /* + * Depending on the CTE name here isn't ideal, but it's the + * only info we have to identify the referenced WITH item. + */ + APP_JUMB_STRING(rte->ctename); + APP_JUMB(rte->ctelevelsup); + break; + case RTE_NAMEDTUPLESTORE: + APP_JUMB_STRING(rte->enrname); + break; + case RTE_RESULT: + break; + default: + elog(ERROR, "unrecognized RTE kind: %d", (int) rte->rtekind); + break; + } + } +} + +/* + * Jumble a rowMarks list + */ +static void +JumbleRowMarks(JumbleState *jstate, List *rowMarks) +{ + ListCell *lc; + + foreach(lc, rowMarks) + { + RowMarkClause *rowmark = lfirst_node(RowMarkClause, lc); + + if (!rowmark->pushedDown) + { + APP_JUMB(rowmark->rti); + APP_JUMB(rowmark->strength); + APP_JUMB(rowmark->waitPolicy); + } + } +} + +/* + * Jumble an expression tree + * + * In general this function should handle all the same node types that + * expression_tree_walker() does, and therefore it's coded to be as parallel + * to that function as possible. However, since we are only invoked on + * queries immediately post-parse-analysis, we need not handle node types + * that only appear in planning. + * + * Note: the reason we don't simply use expression_tree_walker() is that the + * point of that function is to support tree walkers that don't care about + * most tree node types, but here we care about all types. We should complain + * about any unrecognized node type. + */ +static void +JumbleExpr(JumbleState *jstate, Node *node) +{ + ListCell *temp; + + if (node == NULL) + return; + + /* Guard against stack overflow due to overly complex expressions */ + check_stack_depth(); + + /* + * We always emit the node's NodeTag, then any additional fields that are + * considered significant, and then we recurse to any child nodes. + */ + APP_JUMB(node->type); + + switch (nodeTag(node)) + { + case T_Var: + { + Var *var = (Var *) node; + + APP_JUMB(var->varno); + APP_JUMB(var->varattno); + APP_JUMB(var->varlevelsup); + } + break; + case T_Const: + { + Const *c = (Const *) node; + + /* We jumble only the constant's type, not its value */ + APP_JUMB(c->consttype); + /* Also, record its parse location for query normalization */ + RecordConstLocation(jstate, c->location); + } + break; + case T_Param: + { + Param *p = (Param *) node; + + APP_JUMB(p->paramkind); + APP_JUMB(p->paramid); + APP_JUMB(p->paramtype); + /* Also, track the highest external Param id */ + if (p->paramkind == PARAM_EXTERN && + p->paramid > jstate->highest_extern_param_id) + jstate->highest_extern_param_id = p->paramid; + } + break; + case T_Aggref: + { + Aggref *expr = (Aggref *) node; + + APP_JUMB(expr->aggfnoid); + JumbleExpr(jstate, (Node *) expr->aggdirectargs); + JumbleExpr(jstate, (Node *) expr->args); + JumbleExpr(jstate, (Node *) expr->aggorder); + JumbleExpr(jstate, (Node *) expr->aggdistinct); + JumbleExpr(jstate, (Node *) expr->aggfilter); + } + break; + case T_GroupingFunc: + { + GroupingFunc *grpnode = (GroupingFunc *) node; + + JumbleExpr(jstate, (Node *) grpnode->refs); + APP_JUMB(grpnode->agglevelsup); + } + break; + case T_WindowFunc: + { + WindowFunc *expr = (WindowFunc *) node; + + APP_JUMB(expr->winfnoid); + APP_JUMB(expr->winref); + JumbleExpr(jstate, (Node *) expr->args); + JumbleExpr(jstate, (Node *) expr->aggfilter); + } + break; + case T_SubscriptingRef: + { + SubscriptingRef *sbsref = (SubscriptingRef *) node; + + JumbleExpr(jstate, (Node *) sbsref->refupperindexpr); + JumbleExpr(jstate, (Node *) sbsref->reflowerindexpr); + JumbleExpr(jstate, (Node *) sbsref->refexpr); + JumbleExpr(jstate, (Node *) sbsref->refassgnexpr); + } + break; + case T_FuncExpr: + { + FuncExpr *expr = (FuncExpr *) node; + + APP_JUMB(expr->funcid); + JumbleExpr(jstate, (Node *) expr->args); + } + break; + case T_NamedArgExpr: + { + NamedArgExpr *nae = (NamedArgExpr *) node; + + APP_JUMB(nae->argnumber); + JumbleExpr(jstate, (Node *) nae->arg); + } + break; + case T_OpExpr: + case T_DistinctExpr: /* struct-equivalent to OpExpr */ + case T_NullIfExpr: /* struct-equivalent to OpExpr */ + { + OpExpr *expr = (OpExpr *) node; + + APP_JUMB(expr->opno); + JumbleExpr(jstate, (Node *) expr->args); + } + break; + case T_ScalarArrayOpExpr: + { + ScalarArrayOpExpr *expr = (ScalarArrayOpExpr *) node; + + APP_JUMB(expr->opno); + APP_JUMB(expr->useOr); + JumbleExpr(jstate, (Node *) expr->args); + } + break; + case T_BoolExpr: + { + BoolExpr *expr = (BoolExpr *) node; + + APP_JUMB(expr->boolop); + JumbleExpr(jstate, (Node *) expr->args); + } + break; + case T_SubLink: + { + SubLink *sublink = (SubLink *) node; + + APP_JUMB(sublink->subLinkType); + APP_JUMB(sublink->subLinkId); + JumbleExpr(jstate, (Node *) sublink->testexpr); + JumbleQueryInternal(jstate, castNode(Query, sublink->subselect)); + } + break; + case T_FieldSelect: + { + FieldSelect *fs = (FieldSelect *) node; + + APP_JUMB(fs->fieldnum); + JumbleExpr(jstate, (Node *) fs->arg); + } + break; + case T_FieldStore: + { + FieldStore *fstore = (FieldStore *) node; + + JumbleExpr(jstate, (Node *) fstore->arg); + JumbleExpr(jstate, (Node *) fstore->newvals); + } + break; + case T_RelabelType: + { + RelabelType *rt = (RelabelType *) node; + + APP_JUMB(rt->resulttype); + JumbleExpr(jstate, (Node *) rt->arg); + } + break; + case T_CoerceViaIO: + { + CoerceViaIO *cio = (CoerceViaIO *) node; + + APP_JUMB(cio->resulttype); + JumbleExpr(jstate, (Node *) cio->arg); + } + break; + case T_ArrayCoerceExpr: + { + ArrayCoerceExpr *acexpr = (ArrayCoerceExpr *) node; + + APP_JUMB(acexpr->resulttype); + JumbleExpr(jstate, (Node *) acexpr->arg); + JumbleExpr(jstate, (Node *) acexpr->elemexpr); + } + break; + case T_ConvertRowtypeExpr: + { + ConvertRowtypeExpr *crexpr = (ConvertRowtypeExpr *) node; + + APP_JUMB(crexpr->resulttype); + JumbleExpr(jstate, (Node *) crexpr->arg); + } + break; + case T_CollateExpr: + { + CollateExpr *ce = (CollateExpr *) node; + + APP_JUMB(ce->collOid); + JumbleExpr(jstate, (Node *) ce->arg); + } + break; + case T_CaseExpr: + { + CaseExpr *caseexpr = (CaseExpr *) node; + + JumbleExpr(jstate, (Node *) caseexpr->arg); + foreach(temp, caseexpr->args) + { + CaseWhen *when = lfirst_node(CaseWhen, temp); + + JumbleExpr(jstate, (Node *) when->expr); + JumbleExpr(jstate, (Node *) when->result); + } + JumbleExpr(jstate, (Node *) caseexpr->defresult); + } + break; + case T_CaseTestExpr: + { + CaseTestExpr *ct = (CaseTestExpr *) node; + + APP_JUMB(ct->typeId); + } + break; + case T_ArrayExpr: + JumbleExpr(jstate, (Node *) ((ArrayExpr *) node)->elements); + break; + case T_RowExpr: + JumbleExpr(jstate, (Node *) ((RowExpr *) node)->args); + break; + case T_RowCompareExpr: + { + RowCompareExpr *rcexpr = (RowCompareExpr *) node; + + APP_JUMB(rcexpr->rctype); + JumbleExpr(jstate, (Node *) rcexpr->largs); + JumbleExpr(jstate, (Node *) rcexpr->rargs); + } + break; + case T_CoalesceExpr: + JumbleExpr(jstate, (Node *) ((CoalesceExpr *) node)->args); + break; + case T_MinMaxExpr: + { + MinMaxExpr *mmexpr = (MinMaxExpr *) node; + + APP_JUMB(mmexpr->op); + JumbleExpr(jstate, (Node *) mmexpr->args); + } + break; + case T_SQLValueFunction: + { + SQLValueFunction *svf = (SQLValueFunction *) node; + + APP_JUMB(svf->op); + /* type is fully determined by op */ + APP_JUMB(svf->typmod); + } + break; + case T_XmlExpr: + { + XmlExpr *xexpr = (XmlExpr *) node; + + APP_JUMB(xexpr->op); + JumbleExpr(jstate, (Node *) xexpr->named_args); + JumbleExpr(jstate, (Node *) xexpr->args); + } + break; + case T_NullTest: + { + NullTest *nt = (NullTest *) node; + + APP_JUMB(nt->nulltesttype); + JumbleExpr(jstate, (Node *) nt->arg); + } + break; + case T_BooleanTest: + { + BooleanTest *bt = (BooleanTest *) node; + + APP_JUMB(bt->booltesttype); + JumbleExpr(jstate, (Node *) bt->arg); + } + break; + case T_CoerceToDomain: + { + CoerceToDomain *cd = (CoerceToDomain *) node; + + APP_JUMB(cd->resulttype); + JumbleExpr(jstate, (Node *) cd->arg); + } + break; + case T_CoerceToDomainValue: + { + CoerceToDomainValue *cdv = (CoerceToDomainValue *) node; + + APP_JUMB(cdv->typeId); + } + break; + case T_SetToDefault: + { + SetToDefault *sd = (SetToDefault *) node; + + APP_JUMB(sd->typeId); + } + break; + case T_CurrentOfExpr: + { + CurrentOfExpr *ce = (CurrentOfExpr *) node; + + APP_JUMB(ce->cvarno); + if (ce->cursor_name) + APP_JUMB_STRING(ce->cursor_name); + APP_JUMB(ce->cursor_param); + } + break; + case T_NextValueExpr: + { + NextValueExpr *nve = (NextValueExpr *) node; + + APP_JUMB(nve->seqid); + APP_JUMB(nve->typeId); + } + break; + case T_InferenceElem: + { + InferenceElem *ie = (InferenceElem *) node; + + APP_JUMB(ie->infercollid); + APP_JUMB(ie->inferopclass); + JumbleExpr(jstate, ie->expr); + } + break; + case T_TargetEntry: + { + TargetEntry *tle = (TargetEntry *) node; + + APP_JUMB(tle->resno); + APP_JUMB(tle->ressortgroupref); + JumbleExpr(jstate, (Node *) tle->expr); + } + break; + case T_RangeTblRef: + { + RangeTblRef *rtr = (RangeTblRef *) node; + + APP_JUMB(rtr->rtindex); + } + break; + case T_JoinExpr: + { + JoinExpr *join = (JoinExpr *) node; + + APP_JUMB(join->jointype); + APP_JUMB(join->isNatural); + APP_JUMB(join->rtindex); + JumbleExpr(jstate, join->larg); + JumbleExpr(jstate, join->rarg); + JumbleExpr(jstate, join->quals); + } + break; + case T_FromExpr: + { + FromExpr *from = (FromExpr *) node; + + JumbleExpr(jstate, (Node *) from->fromlist); + JumbleExpr(jstate, from->quals); + } + break; + case T_OnConflictExpr: + { + OnConflictExpr *conf = (OnConflictExpr *) node; + + APP_JUMB(conf->action); + JumbleExpr(jstate, (Node *) conf->arbiterElems); + JumbleExpr(jstate, conf->arbiterWhere); + JumbleExpr(jstate, (Node *) conf->onConflictSet); + JumbleExpr(jstate, conf->onConflictWhere); + APP_JUMB(conf->constraint); + APP_JUMB(conf->exclRelIndex); + JumbleExpr(jstate, (Node *) conf->exclRelTlist); + } + break; + case T_List: + foreach(temp, (List *) node) + { + JumbleExpr(jstate, (Node *) lfirst(temp)); + } + break; + case T_IntList: + foreach(temp, (List *) node) + { + APP_JUMB(lfirst_int(temp)); + } + break; + case T_SortGroupClause: + { + SortGroupClause *sgc = (SortGroupClause *) node; + + APP_JUMB(sgc->tleSortGroupRef); + APP_JUMB(sgc->eqop); + APP_JUMB(sgc->sortop); + APP_JUMB(sgc->nulls_first); + } + break; + case T_GroupingSet: + { + GroupingSet *gsnode = (GroupingSet *) node; + + JumbleExpr(jstate, (Node *) gsnode->content); + } + break; + case T_WindowClause: + { + WindowClause *wc = (WindowClause *) node; + + APP_JUMB(wc->winref); + APP_JUMB(wc->frameOptions); + JumbleExpr(jstate, (Node *) wc->partitionClause); + JumbleExpr(jstate, (Node *) wc->orderClause); + JumbleExpr(jstate, wc->startOffset); + JumbleExpr(jstate, wc->endOffset); + } + break; + case T_CommonTableExpr: + { + CommonTableExpr *cte = (CommonTableExpr *) node; + + /* we store the string name because RTE_CTE RTEs need it */ + APP_JUMB_STRING(cte->ctename); + APP_JUMB(cte->ctematerialized); + JumbleQueryInternal(jstate, castNode(Query, cte->ctequery)); + } + break; + case T_SetOperationStmt: + { + SetOperationStmt *setop = (SetOperationStmt *) node; + + APP_JUMB(setop->op); + APP_JUMB(setop->all); + JumbleExpr(jstate, setop->larg); + JumbleExpr(jstate, setop->rarg); + } + break; + case T_RangeTblFunction: + { + RangeTblFunction *rtfunc = (RangeTblFunction *) node; + + JumbleExpr(jstate, rtfunc->funcexpr); + } + break; + case T_TableFunc: + { + TableFunc *tablefunc = (TableFunc *) node; + + JumbleExpr(jstate, tablefunc->docexpr); + JumbleExpr(jstate, tablefunc->rowexpr); + JumbleExpr(jstate, (Node *) tablefunc->colexprs); + } + break; + case T_TableSampleClause: + { + TableSampleClause *tsc = (TableSampleClause *) node; + + APP_JUMB(tsc->tsmhandler); + JumbleExpr(jstate, (Node *) tsc->args); + JumbleExpr(jstate, (Node *) tsc->repeatable); + } + break; + default: + /* Only a warning, since we can stumble along anyway */ + elog(WARNING, "unrecognized node type: %d", + (int) nodeTag(node)); + break; + } +} + +/* + * Record location of constant within query string of query tree + * that is currently being walked. + */ +static void +RecordConstLocation(JumbleState *jstate, int location) +{ + /* -1 indicates unknown or undefined location */ + if (location >= 0) + { + /* enlarge array if needed */ + if (jstate->clocations_count >= jstate->clocations_buf_size) + { + jstate->clocations_buf_size *= 2; + jstate->clocations = (LocationLen *) + repalloc(jstate->clocations, + jstate->clocations_buf_size * + sizeof(LocationLen)); + } + jstate->clocations[jstate->clocations_count].location = location; + /* initialize lengths to -1 to simplify third-party module usage */ + jstate->clocations[jstate->clocations_count].length = -1; + jstate->clocations_count++; + } +} |