diff options
Diffstat (limited to 'src/backend/utils/adt/jsonpath.c')
| -rw-r--r-- | src/backend/utils/adt/jsonpath.c | 257 |
1 files changed, 257 insertions, 0 deletions
diff --git a/src/backend/utils/adt/jsonpath.c b/src/backend/utils/adt/jsonpath.c index 91af0300952..0ac14153aae 100644 --- a/src/backend/utils/adt/jsonpath.c +++ b/src/backend/utils/adt/jsonpath.c @@ -67,7 +67,9 @@ #include "lib/stringinfo.h" #include "libpq/pqformat.h" #include "miscadmin.h" +#include "nodes/nodeFuncs.h" #include "utils/builtins.h" +#include "utils/formatting.h" #include "utils/json.h" #include "utils/jsonpath.h" @@ -1077,3 +1079,258 @@ jspGetArraySubscript(JsonPathItem *v, JsonPathItem *from, JsonPathItem *to, return true; } + +/* SQL/JSON datatype status: */ +typedef enum JsonPathDatatypeStatus +{ + jpdsNonDateTime, /* null, bool, numeric, string, array, object */ + jpdsUnknownDateTime, /* unknown datetime type */ + jpdsDateTimeZoned, /* timetz, timestamptz */ + jpdsDateTimeNonZoned /* time, timestamp, date */ +} JsonPathDatatypeStatus; + +/* Context for jspIsMutableWalker() */ +typedef struct JsonPathMutableContext +{ + List *varnames; /* list of variable names */ + List *varexprs; /* list of variable expressions */ + JsonPathDatatypeStatus current; /* status of @ item */ + bool lax; /* jsonpath is lax or strict */ + bool mutable; /* resulting mutability status */ +} JsonPathMutableContext; + +/* + * Recursive walker for jspIsMutable() + */ +static JsonPathDatatypeStatus +jspIsMutableWalker(JsonPathItem *jpi, JsonPathMutableContext *cxt) +{ + JsonPathItem next; + JsonPathDatatypeStatus status = jpdsNonDateTime; + + while (!cxt->mutable) + { + JsonPathItem arg; + JsonPathDatatypeStatus leftStatus; + JsonPathDatatypeStatus rightStatus; + + switch (jpi->type) + { + case jpiRoot: + Assert(status == jpdsNonDateTime); + break; + + case jpiCurrent: + Assert(status == jpdsNonDateTime); + status = cxt->current; + break; + + case jpiFilter: + { + JsonPathDatatypeStatus prevStatus = cxt->current; + + cxt->current = status; + jspGetArg(jpi, &arg); + jspIsMutableWalker(&arg, cxt); + + cxt->current = prevStatus; + break; + } + + case jpiVariable: + { + int32 len; + const char *name = jspGetString(jpi, &len); + ListCell *lc1; + ListCell *lc2; + + Assert(status == jpdsNonDateTime); + + forboth(lc1, cxt->varnames, lc2, cxt->varexprs) + { + String *varname = lfirst_node(String, lc1); + Node *varexpr = lfirst(lc2); + + if (strncmp(varname->sval, name, len)) + continue; + + switch (exprType(varexpr)) + { + case DATEOID: + case TIMEOID: + case TIMESTAMPOID: + status = jpdsDateTimeNonZoned; + break; + + case TIMETZOID: + case TIMESTAMPTZOID: + status = jpdsDateTimeZoned; + break; + + default: + status = jpdsNonDateTime; + break; + } + + break; + } + break; + } + + case jpiEqual: + case jpiNotEqual: + case jpiLess: + case jpiGreater: + case jpiLessOrEqual: + case jpiGreaterOrEqual: + Assert(status == jpdsNonDateTime); + jspGetLeftArg(jpi, &arg); + leftStatus = jspIsMutableWalker(&arg, cxt); + + jspGetRightArg(jpi, &arg); + rightStatus = jspIsMutableWalker(&arg, cxt); + + /* + * Comparison of datetime type with different timezone status + * is mutable. + */ + if (leftStatus != jpdsNonDateTime && + rightStatus != jpdsNonDateTime && + (leftStatus == jpdsUnknownDateTime || + rightStatus == jpdsUnknownDateTime || + leftStatus != rightStatus)) + cxt->mutable = true; + break; + + case jpiNot: + case jpiIsUnknown: + case jpiExists: + case jpiPlus: + case jpiMinus: + Assert(status == jpdsNonDateTime); + jspGetArg(jpi, &arg); + jspIsMutableWalker(&arg, cxt); + break; + + case jpiAnd: + case jpiOr: + case jpiAdd: + case jpiSub: + case jpiMul: + case jpiDiv: + case jpiMod: + case jpiStartsWith: + Assert(status == jpdsNonDateTime); + jspGetLeftArg(jpi, &arg); + jspIsMutableWalker(&arg, cxt); + jspGetRightArg(jpi, &arg); + jspIsMutableWalker(&arg, cxt); + break; + + case jpiIndexArray: + for (int i = 0; i < jpi->content.array.nelems; i++) + { + JsonPathItem from; + JsonPathItem to; + + if (jspGetArraySubscript(jpi, &from, &to, i)) + jspIsMutableWalker(&to, cxt); + + jspIsMutableWalker(&from, cxt); + } + /* FALLTHROUGH */ + + case jpiAnyArray: + if (!cxt->lax) + status = jpdsNonDateTime; + break; + + case jpiAny: + if (jpi->content.anybounds.first > 0) + status = jpdsNonDateTime; + break; + + case jpiDatetime: + if (jpi->content.arg) + { + char *template; + int flags; + + jspGetArg(jpi, &arg); + if (arg.type != jpiString) + { + status = jpdsNonDateTime; + break; /* there will be runtime error */ + } + + template = jspGetString(&arg, NULL); + flags = datetime_format_flags(template, NULL); + if (flags & DCH_ZONED) + status = jpdsDateTimeZoned; + else + status = jpdsDateTimeNonZoned; + } + else + { + status = jpdsUnknownDateTime; + } + break; + + case jpiLikeRegex: + Assert(status == jpdsNonDateTime); + jspInitByBuffer(&arg, jpi->base, jpi->content.like_regex.expr); + jspIsMutableWalker(&arg, cxt); + break; + + /* literals */ + case jpiNull: + case jpiString: + case jpiNumeric: + case jpiBool: + /* accessors */ + case jpiKey: + case jpiAnyKey: + /* special items */ + case jpiSubscript: + case jpiLast: + /* item methods */ + case jpiType: + case jpiSize: + case jpiAbs: + case jpiFloor: + case jpiCeiling: + case jpiDouble: + case jpiKeyValue: + status = jpdsNonDateTime; + break; + } + + if (!jspGetNext(jpi, &next)) + break; + + jpi = &next; + } + + return status; +} + +/* + * Check whether jsonpath expression is immutable or not. + */ +bool +jspIsMutable(JsonPath *path, List *varnames, List *varexprs) +{ + JsonPathMutableContext cxt; + JsonPathItem jpi; + + cxt.varnames = varnames; + cxt.varexprs = varexprs; + cxt.current = jpdsNonDateTime; + cxt.lax = (path->header & JSONPATH_LAX) != 0; + cxt.mutable = false; + + jspInit(&jpi, path); + jspIsMutableWalker(&jpi, &cxt); + + return cxt.mutable; +} |