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postgresql/src/backend/utils/adt/jsonpath_exec.c

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/*-------------------------------------------------------------------------
*
* jsonpath_exec.c
* Routines for SQL/JSON path execution.
*
* Jsonpath is executed in the global context stored in JsonPathExecContext,
* which is passed to almost every function involved into execution. Entry
* point for jsonpath execution is executeJsonPath() function, which
* initializes execution context including initial JsonPathItem and JsonbValue,
* flags, stack for calculation of @ in filters.
*
* The result of jsonpath query execution is enum JsonPathExecResult and
* if succeeded sequence of JsonbValue, written to JsonValueList *found, which
* is passed through the jsonpath items. When found == NULL, we're inside
* exists-query and we're interested only in whether result is empty. In this
* case execution is stopped once first result item is found, and the only
* execution result is JsonPathExecResult. The values of JsonPathExecResult
* are following:
* - jperOk -- result sequence is not empty
* - jperNotFound -- result sequence is empty
* - jperError -- error occurred during execution
*
* Jsonpath is executed recursively (see executeItem()) starting form the
* first path item (which in turn might be, for instance, an arithmetic
* expression evaluated separately). On each step single JsonbValue obtained
* from previous path item is processed. The result of processing is a
* sequence of JsonbValue (probably empty), which is passed to the next path
* item one by one. When there is no next path item, then JsonbValue is added
* to the 'found' list. When found == NULL, then execution functions just
* return jperOk (see executeNextItem()).
*
* Many of jsonpath operations require automatic unwrapping of arrays in lax
* mode. So, if input value is array, then corresponding operation is
* processed not on array itself, but on all of its members one by one.
* executeItemOptUnwrapTarget() function have 'unwrap' argument, which indicates
* whether unwrapping of array is needed. When unwrap == true, each of array
* members is passed to executeItemOptUnwrapTarget() again but with unwrap == false
* in order to evade subsequent array unwrapping.
*
* All boolean expressions (predicates) are evaluated by executeBoolItem()
* function, which returns tri-state JsonPathBool. When error is occurred
* during predicate execution, it returns jpbUnknown. According to standard
* predicates can be only inside filters. But we support their usage as
* jsonpath expression. This helps us to implement @@ operator. In this case
* resulting JsonPathBool is transformed into jsonb bool or null.
*
* Arithmetic and boolean expression are evaluated recursively from expression
* tree top down to the leaves. Therefore, for binary arithmetic expressions
* we calculate operands first. Then we check that results are numeric
* singleton lists, calculate the result and pass it to the next path item.
*
* Copyright (c) 2019, PostgreSQL Global Development Group
*
* IDENTIFICATION
* src/backend/utils/adt/jsonpath_exec.c
*
*-------------------------------------------------------------------------
*/
#include "postgres.h"
#include "catalog/pg_collation.h"
#include "catalog/pg_type.h"
#include "funcapi.h"
#include "lib/stringinfo.h"
#include "miscadmin.h"
#include "regex/regex.h"
#include "utils/builtins.h"
#include "utils/datum.h"
#include "utils/formatting.h"
#include "utils/float.h"
#include "utils/guc.h"
#include "utils/json.h"
#include "utils/jsonpath.h"
#include "utils/date.h"
#include "utils/timestamp.h"
#include "utils/varlena.h"
/*
* Represents "base object" and it's "id" for .keyvalue() evaluation.
*/
typedef struct JsonBaseObjectInfo
{
JsonbContainer *jbc;
int id;
} JsonBaseObjectInfo;
/*
* Context of jsonpath execution.
*/
typedef struct JsonPathExecContext
{
Jsonb *vars; /* variables to substitute into jsonpath */
JsonbValue *root; /* for $ evaluation */
JsonbValue *current; /* for @ evaluation */
JsonBaseObjectInfo baseObject; /* "base object" for .keyvalue()
* evaluation */
int lastGeneratedObjectId; /* "id" counter for .keyvalue()
* evaluation */
int innermostArraySize; /* for LAST array index evaluation */
bool laxMode; /* true for "lax" mode, false for "strict"
* mode */
bool ignoreStructuralErrors; /* with "true" structural errors such
* as absence of required json item or
* unexpected json item type are
* ignored */
bool throwErrors; /* with "false" all suppressible errors are
* suppressed */
} JsonPathExecContext;
/* Context for LIKE_REGEX execution. */
typedef struct JsonLikeRegexContext
{
text *regex;
int cflags;
} JsonLikeRegexContext;
/* Result of jsonpath predicate evaluation */
typedef enum JsonPathBool
{
jpbFalse = 0,
jpbTrue = 1,
jpbUnknown = 2
} JsonPathBool;
/* Result of jsonpath expression evaluation */
typedef enum JsonPathExecResult
{
jperOk = 0,
jperNotFound = 1,
jperError = 2
} JsonPathExecResult;
#define jperIsError(jper) ((jper) == jperError)
/*
* List of jsonb values with shortcut for single-value list.
*/
typedef struct JsonValueList
{
JsonbValue *singleton;
List *list;
} JsonValueList;
typedef struct JsonValueListIterator
{
JsonbValue *value;
List *list;
ListCell *next;
} JsonValueListIterator;
/* strict/lax flags is decomposed into four [un]wrap/error flags */
#define jspStrictAbsenseOfErrors(cxt) (!(cxt)->laxMode)
#define jspAutoUnwrap(cxt) ((cxt)->laxMode)
#define jspAutoWrap(cxt) ((cxt)->laxMode)
#define jspIgnoreStructuralErrors(cxt) ((cxt)->ignoreStructuralErrors)
#define jspThrowErrors(cxt) ((cxt)->throwErrors)
/* Convenience macro: return or throw error depending on context */
#define RETURN_ERROR(throw_error) \
do { \
if (jspThrowErrors(cxt)) \
throw_error; \
else \
return jperError; \
} while (0)
typedef JsonPathBool (*JsonPathPredicateCallback) (JsonPathItem *jsp,
JsonbValue *larg,
JsonbValue *rarg,
void *param);
typedef Numeric (*BinaryArithmFunc) (Numeric num1, Numeric num2, bool *error);
static JsonPathExecResult executeJsonPath(JsonPath *path, Jsonb *vars,
Jsonb *json, bool throwErrors, JsonValueList *result);
static JsonPathExecResult executeItem(JsonPathExecContext *cxt,
JsonPathItem *jsp, JsonbValue *jb, JsonValueList *found);
static JsonPathExecResult executeItemOptUnwrapTarget(JsonPathExecContext *cxt,
JsonPathItem *jsp, JsonbValue *jb,
JsonValueList *found, bool unwrap);
static JsonPathExecResult executeItemUnwrapTargetArray(JsonPathExecContext *cxt,
JsonPathItem *jsp, JsonbValue *jb,
JsonValueList *found, bool unwrapElements);
static JsonPathExecResult executeNextItem(JsonPathExecContext *cxt,
JsonPathItem *cur, JsonPathItem *next,
JsonbValue *v, JsonValueList *found, bool copy);
static JsonPathExecResult executeItemOptUnwrapResult(JsonPathExecContext *cxt, JsonPathItem *jsp, JsonbValue *jb,
bool unwrap, JsonValueList *found);
static JsonPathExecResult executeItemOptUnwrapResultNoThrow(JsonPathExecContext *cxt, JsonPathItem *jsp,
JsonbValue *jb, bool unwrap, JsonValueList *found);
static JsonPathBool executeBoolItem(JsonPathExecContext *cxt,
JsonPathItem *jsp, JsonbValue *jb, bool canHaveNext);
static JsonPathBool executeNestedBoolItem(JsonPathExecContext *cxt,
JsonPathItem *jsp, JsonbValue *jb);
static JsonPathExecResult executeAnyItem(JsonPathExecContext *cxt,
JsonPathItem *jsp, JsonbContainer *jbc, JsonValueList *found,
uint32 level, uint32 first, uint32 last,
bool ignoreStructuralErrors, bool unwrapNext);
static JsonPathBool executePredicate(JsonPathExecContext *cxt,
JsonPathItem *pred, JsonPathItem *larg, JsonPathItem *rarg,
JsonbValue *jb, bool unwrapRightArg,
JsonPathPredicateCallback exec, void *param);
static JsonPathExecResult executeBinaryArithmExpr(JsonPathExecContext *cxt,
JsonPathItem *jsp, JsonbValue *jb,
BinaryArithmFunc func, JsonValueList *found);
static JsonPathExecResult executeUnaryArithmExpr(JsonPathExecContext *cxt,
JsonPathItem *jsp, JsonbValue *jb, PGFunction func,
JsonValueList *found);
static JsonPathBool executeStartsWith(JsonPathItem *jsp,
JsonbValue *whole, JsonbValue *initial, void *param);
static JsonPathBool executeLikeRegex(JsonPathItem *jsp, JsonbValue *str,
JsonbValue *rarg, void *param);
static JsonPathExecResult executeNumericItemMethod(JsonPathExecContext *cxt,
JsonPathItem *jsp, JsonbValue *jb, bool unwrap, PGFunction func,
JsonValueList *found);
static JsonPathExecResult executeKeyValueMethod(JsonPathExecContext *cxt,
JsonPathItem *jsp, JsonbValue *jb, JsonValueList *found);
static JsonPathExecResult appendBoolResult(JsonPathExecContext *cxt,
JsonPathItem *jsp, JsonValueList *found, JsonPathBool res);
static void getJsonPathItem(JsonPathExecContext *cxt, JsonPathItem *item,
JsonbValue *value);
static void getJsonPathVariable(JsonPathExecContext *cxt,
JsonPathItem *variable, Jsonb *vars, JsonbValue *value);
static int JsonbArraySize(JsonbValue *jb);
static JsonPathBool executeComparison(JsonPathItem *cmp, JsonbValue *lv,
JsonbValue *rv, void *p);
static JsonPathBool compareItems(int32 op, JsonbValue *jb1, JsonbValue *jb2);
static int compareNumeric(Numeric a, Numeric b);
static JsonbValue *copyJsonbValue(JsonbValue *src);
static JsonPathExecResult getArrayIndex(JsonPathExecContext *cxt,
JsonPathItem *jsp, JsonbValue *jb, int32 *index);
static JsonBaseObjectInfo setBaseObject(JsonPathExecContext *cxt,
JsonbValue *jbv, int32 id);
static void JsonValueListAppend(JsonValueList *jvl, JsonbValue *jbv);
static int JsonValueListLength(const JsonValueList *jvl);
static bool JsonValueListIsEmpty(JsonValueList *jvl);
static JsonbValue *JsonValueListHead(JsonValueList *jvl);
static List *JsonValueListGetList(JsonValueList *jvl);
static void JsonValueListInitIterator(const JsonValueList *jvl,
JsonValueListIterator *it);
static JsonbValue *JsonValueListNext(const JsonValueList *jvl,
JsonValueListIterator *it);
static int JsonbType(JsonbValue *jb);
static JsonbValue *JsonbInitBinary(JsonbValue *jbv, Jsonb *jb);
static int JsonbType(JsonbValue *jb);
static JsonbValue *getScalar(JsonbValue *scalar, enum jbvType type);
static JsonbValue *wrapItemsInArray(const JsonValueList *items);
/****************** User interface to JsonPath executor ********************/
/*
* jsonb_path_exists
* Returns true if jsonpath returns at least one item for the specified
* jsonb value. This function and jsonb_path_match() are used to
* implement @? and @@ operators, which in turn are intended to have an
* index support. Thus, it's desirable to make it easier to achieve
* consistency between index scan results and sequential scan results.
* So, we throw as less errors as possible. Regarding this function,
* such behavior also matches behavior of JSON_EXISTS() clause of
* SQL/JSON. Regarding jsonb_path_match(), this function doesn't have
* an analogy in SQL/JSON, so we define its behavior on our own.
*/
Datum
jsonb_path_exists(PG_FUNCTION_ARGS)
{
Jsonb *jb = PG_GETARG_JSONB_P(0);
JsonPath *jp = PG_GETARG_JSONPATH_P(1);
JsonPathExecResult res;
Jsonb *vars = NULL;
bool silent = true;
if (PG_NARGS() == 4)
{
vars = PG_GETARG_JSONB_P(2);
silent = PG_GETARG_BOOL(3);
}
res = executeJsonPath(jp, vars, jb, !silent, NULL);
PG_FREE_IF_COPY(jb, 0);
PG_FREE_IF_COPY(jp, 1);
if (jperIsError(res))
PG_RETURN_NULL();
PG_RETURN_BOOL(res == jperOk);
}
/*
* jsonb_path_exists_opr
* Implementation of operator "jsonb @? jsonpath" (2-argument version of
* jsonb_path_exists()).
*/
Datum
jsonb_path_exists_opr(PG_FUNCTION_ARGS)
{
/* just call the other one -- it can handle both cases */
return jsonb_path_exists(fcinfo);
}
/*
* jsonb_path_match
* Returns jsonpath predicate result item for the specified jsonb value.
* See jsonb_path_exists() comment for details regarding error handling.
*/
Datum
jsonb_path_match(PG_FUNCTION_ARGS)
{
Jsonb *jb = PG_GETARG_JSONB_P(0);
JsonPath *jp = PG_GETARG_JSONPATH_P(1);
JsonValueList found = {0};
Jsonb *vars = NULL;
bool silent = true;
if (PG_NARGS() == 4)
{
vars = PG_GETARG_JSONB_P(2);
silent = PG_GETARG_BOOL(3);
}
(void) executeJsonPath(jp, vars, jb, !silent, &found);
PG_FREE_IF_COPY(jb, 0);
PG_FREE_IF_COPY(jp, 1);
if (JsonValueListLength(&found) == 1)
{
JsonbValue *jbv = JsonValueListHead(&found);
if (jbv->type == jbvBool)
PG_RETURN_BOOL(jbv->val.boolean);
if (jbv->type == jbvNull)
PG_RETURN_NULL();
}
if (!silent)
ereport(ERROR,
(errcode(ERRCODE_SINGLETON_SQL_JSON_ITEM_REQUIRED),
errmsg("single boolean result is expected")));
PG_RETURN_NULL();
}
/*
* jsonb_path_match_opr
* Implementation of operator "jsonb @@ jsonpath" (2-argument version of
* jsonb_path_match()).
*/
Datum
jsonb_path_match_opr(PG_FUNCTION_ARGS)
{
/* just call the other one -- it can handle both cases */
return jsonb_path_match(fcinfo);
}
/*
* jsonb_path_query
* Executes jsonpath for given jsonb document and returns result as
* rowset.
*/
Datum
jsonb_path_query(PG_FUNCTION_ARGS)
{
FuncCallContext *funcctx;
List *found;
JsonbValue *v;
ListCell *c;
if (SRF_IS_FIRSTCALL())
{
JsonPath *jp;
Jsonb *jb;
MemoryContext oldcontext;
Jsonb *vars;
bool silent;
JsonValueList found = {0};
funcctx = SRF_FIRSTCALL_INIT();
oldcontext = MemoryContextSwitchTo(funcctx->multi_call_memory_ctx);
jb = PG_GETARG_JSONB_P_COPY(0);
jp = PG_GETARG_JSONPATH_P_COPY(1);
vars = PG_GETARG_JSONB_P_COPY(2);
silent = PG_GETARG_BOOL(3);
(void) executeJsonPath(jp, vars, jb, !silent, &found);
funcctx->user_fctx = JsonValueListGetList(&found);
MemoryContextSwitchTo(oldcontext);
}
funcctx = SRF_PERCALL_SETUP();
found = funcctx->user_fctx;
c = list_head(found);
if (c == NULL)
SRF_RETURN_DONE(funcctx);
v = lfirst(c);
funcctx->user_fctx = list_delete_first(found);
SRF_RETURN_NEXT(funcctx, JsonbPGetDatum(JsonbValueToJsonb(v)));
}
/*
* jsonb_path_query_array
* Executes jsonpath for given jsonb document and returns result as
* jsonb array.
*/
Datum
jsonb_path_query_array(PG_FUNCTION_ARGS)
{
Jsonb *jb = PG_GETARG_JSONB_P(0);
JsonPath *jp = PG_GETARG_JSONPATH_P(1);
JsonValueList found = {0};
Jsonb *vars = PG_GETARG_JSONB_P(2);
bool silent = PG_GETARG_BOOL(3);
(void) executeJsonPath(jp, vars, jb, !silent, &found);
PG_RETURN_JSONB_P(JsonbValueToJsonb(wrapItemsInArray(&found)));
}
/*
* jsonb_path_query_first
* Executes jsonpath for given jsonb document and returns first result
* item. If there are no items, NULL returned.
*/
Datum
jsonb_path_query_first(PG_FUNCTION_ARGS)
{
Jsonb *jb = PG_GETARG_JSONB_P(0);
JsonPath *jp = PG_GETARG_JSONPATH_P(1);
JsonValueList found = {0};
Jsonb *vars = PG_GETARG_JSONB_P(2);
bool silent = PG_GETARG_BOOL(3);
(void) executeJsonPath(jp, vars, jb, !silent, &found);
if (JsonValueListLength(&found) >= 1)
PG_RETURN_JSONB_P(JsonbValueToJsonb(JsonValueListHead(&found)));
else
PG_RETURN_NULL();
}
/********************Execute functions for JsonPath**************************/
/*
* Interface to jsonpath executor
*
* 'path' - jsonpath to be executed
* 'vars' - variables to be substituted to jsonpath
* 'json' - target document for jsonpath evaluation
* 'throwErrors' - whether we should throw suppressible errors
* 'result' - list to store result items into
*
* Returns an error if a recoverable error happens during processing, or NULL
* on no error.
*
* Note, jsonb and jsonpath values should be available and untoasted during
* work because JsonPathItem, JsonbValue and result item could have pointers
* into input values. If caller needs to just check if document matches
* jsonpath, then it doesn't provide a result arg. In this case executor
* works till first positive result and does not check the rest if possible.
* In other case it tries to find all the satisfied result items.
*/
static JsonPathExecResult
executeJsonPath(JsonPath *path, Jsonb *vars, Jsonb *json, bool throwErrors,
JsonValueList *result)
{
JsonPathExecContext cxt;
JsonPathExecResult res;
JsonPathItem jsp;
JsonbValue jbv;
jspInit(&jsp, path);
if (!JsonbExtractScalar(&json->root, &jbv))
JsonbInitBinary(&jbv, json);
if (vars && !JsonContainerIsObject(&vars->root))
{
ereport(ERROR,
(errcode(ERRCODE_INVALID_PARAMETER_VALUE),
errmsg("\"vars\" argument is not an object"),
errdetail("Jsonpath parameters should be encoded as key-value pairs of \"vars\" object.")));
}
cxt.vars = vars;
cxt.laxMode = (path->header & JSONPATH_LAX) != 0;
cxt.ignoreStructuralErrors = cxt.laxMode;
cxt.root = &jbv;
cxt.current = &jbv;
cxt.baseObject.jbc = NULL;
cxt.baseObject.id = 0;
cxt.lastGeneratedObjectId = vars ? 2 : 1;
cxt.innermostArraySize = -1;
cxt.throwErrors = throwErrors;
if (jspStrictAbsenseOfErrors(&cxt) && !result)
{
/*
* In strict mode we must get a complete list of values to check that
* there are no errors at all.
*/
JsonValueList vals = {0};
res = executeItem(&cxt, &jsp, &jbv, &vals);
if (jperIsError(res))
return res;
return JsonValueListIsEmpty(&vals) ? jperNotFound : jperOk;
}
res = executeItem(&cxt, &jsp, &jbv, result);
Assert(!throwErrors || !jperIsError(res));
return res;
}
/*
* Execute jsonpath with automatic unwrapping of current item in lax mode.
*/
static JsonPathExecResult
executeItem(JsonPathExecContext *cxt, JsonPathItem *jsp,
JsonbValue *jb, JsonValueList *found)
{
return executeItemOptUnwrapTarget(cxt, jsp, jb, found, jspAutoUnwrap(cxt));
}
/*
* Main jsonpath executor function: walks on jsonpath structure, finds
* relevant parts of jsonb and evaluates expressions over them.
* When 'unwrap' is true current SQL/JSON item is unwrapped if it is an array.
*/
static JsonPathExecResult
executeItemOptUnwrapTarget(JsonPathExecContext *cxt, JsonPathItem *jsp,
JsonbValue *jb, JsonValueList *found, bool unwrap)
{
JsonPathItem elem;
JsonPathExecResult res = jperNotFound;
JsonBaseObjectInfo baseObject;
check_stack_depth();
CHECK_FOR_INTERRUPTS();
switch (jsp->type)
{
/* all boolean item types: */
case jpiAnd:
case jpiOr:
case jpiNot:
case jpiIsUnknown:
case jpiEqual:
case jpiNotEqual:
case jpiLess:
case jpiGreater:
case jpiLessOrEqual:
case jpiGreaterOrEqual:
case jpiExists:
case jpiStartsWith:
case jpiLikeRegex:
{
JsonPathBool st = executeBoolItem(cxt, jsp, jb, true);
res = appendBoolResult(cxt, jsp, found, st);
break;
}
case jpiKey:
if (JsonbType(jb) == jbvObject)
{
JsonbValue *v;
JsonbValue key;
key.type = jbvString;
key.val.string.val = jspGetString(jsp, &key.val.string.len);
v = findJsonbValueFromContainer(jb->val.binary.data,
JB_FOBJECT, &key);
if (v != NULL)
{
res = executeNextItem(cxt, jsp, NULL,
v, found, false);
/* free value if it was not added to found list */
if (jspHasNext(jsp) || !found)
pfree(v);
}
else if (!jspIgnoreStructuralErrors(cxt))
{
Assert(found);
if (!jspThrowErrors(cxt))
return jperError;
ereport(ERROR,
(errcode(ERRCODE_SQL_JSON_MEMBER_NOT_FOUND), \
errmsg("JSON object does not contain key \"%s\"",
pnstrdup(key.val.string.val,
key.val.string.len))));
}
}
else if (unwrap && JsonbType(jb) == jbvArray)
return executeItemUnwrapTargetArray(cxt, jsp, jb, found, false);
else if (!jspIgnoreStructuralErrors(cxt))
{
Assert(found);
RETURN_ERROR(ereport(ERROR,
(errcode(ERRCODE_SQL_JSON_MEMBER_NOT_FOUND),
errmsg("jsonpath member accessor can only be applied to an object"))));
}
break;
case jpiRoot:
jb = cxt->root;
baseObject = setBaseObject(cxt, jb, 0);
res = executeNextItem(cxt, jsp, NULL, jb, found, true);
cxt->baseObject = baseObject;
break;
case jpiCurrent:
res = executeNextItem(cxt, jsp, NULL, cxt->current,
found, true);
break;
case jpiAnyArray:
if (JsonbType(jb) == jbvArray)
{
bool hasNext = jspGetNext(jsp, &elem);
res = executeItemUnwrapTargetArray(cxt, hasNext ? &elem : NULL,
jb, found, jspAutoUnwrap(cxt));
}
else if (jspAutoWrap(cxt))
res = executeNextItem(cxt, jsp, NULL, jb, found, true);
else if (!jspIgnoreStructuralErrors(cxt))
RETURN_ERROR(ereport(ERROR,
(errcode(ERRCODE_SQL_JSON_ARRAY_NOT_FOUND),
errmsg("jsonpath wildcard array accessor can only be applied to an array"))));
break;
case jpiIndexArray:
if (JsonbType(jb) == jbvArray || jspAutoWrap(cxt))
{
int innermostArraySize = cxt->innermostArraySize;
int i;
int size = JsonbArraySize(jb);
bool singleton = size < 0;
bool hasNext = jspGetNext(jsp, &elem);
if (singleton)
size = 1;
cxt->innermostArraySize = size; /* for LAST evaluation */
for (i = 0; i < jsp->content.array.nelems; i++)
{
JsonPathItem from;
JsonPathItem to;
int32 index;
int32 index_from;
int32 index_to;
bool range = jspGetArraySubscript(jsp, &from,
&to, i);
res = getArrayIndex(cxt, &from, jb, &index_from);
if (jperIsError(res))
break;
if (range)
{
res = getArrayIndex(cxt, &to, jb, &index_to);
if (jperIsError(res))
break;
}
else
index_to = index_from;
if (!jspIgnoreStructuralErrors(cxt) &&
(index_from < 0 ||
index_from > index_to ||
index_to >= size))
RETURN_ERROR(ereport(ERROR,
(errcode(ERRCODE_INVALID_SQL_JSON_SUBSCRIPT),
errmsg("jsonpath array subscript is out of bounds"))));
if (index_from < 0)
index_from = 0;
if (index_to >= size)
index_to = size - 1;
res = jperNotFound;
for (index = index_from; index <= index_to; index++)
{
JsonbValue *v;
bool copy;
if (singleton)
{
v = jb;
copy = true;
}
else
{
v = getIthJsonbValueFromContainer(jb->val.binary.data,
(uint32) index);
if (v == NULL)
continue;
copy = false;
}
if (!hasNext && !found)
return jperOk;
res = executeNextItem(cxt, jsp, &elem, v, found,
copy);
if (jperIsError(res))
break;
if (res == jperOk && !found)
break;
}
if (jperIsError(res))
break;
if (res == jperOk && !found)
break;
}
cxt->innermostArraySize = innermostArraySize;
}
else if (!jspIgnoreStructuralErrors(cxt))
{
RETURN_ERROR(ereport(ERROR,
(errcode(ERRCODE_SQL_JSON_ARRAY_NOT_FOUND),
errmsg("jsonpath array accessor can only be applied to an array"))));
}
break;
case jpiLast:
{
JsonbValue tmpjbv;
JsonbValue *lastjbv;
int last;
bool hasNext = jspGetNext(jsp, &elem);
if (cxt->innermostArraySize < 0)
elog(ERROR, "evaluating jsonpath LAST outside of array subscript");
if (!hasNext && !found)
{
res = jperOk;
break;
}
last = cxt->innermostArraySize - 1;
lastjbv = hasNext ? &tmpjbv : palloc(sizeof(*lastjbv));
lastjbv->type = jbvNumeric;
lastjbv->val.numeric =
DatumGetNumeric(DirectFunctionCall1(int4_numeric,
Int32GetDatum(last)));
res = executeNextItem(cxt, jsp, &elem,
lastjbv, found, hasNext);
}
break;
case jpiAnyKey:
if (JsonbType(jb) == jbvObject)
{
bool hasNext = jspGetNext(jsp, &elem);
if (jb->type != jbvBinary)
elog(ERROR, "invalid jsonb object type: %d", jb->type);
return executeAnyItem
(cxt, hasNext ? &elem : NULL,
jb->val.binary.data, found, 1, 1, 1,
false, jspAutoUnwrap(cxt));
}
else if (unwrap && JsonbType(jb) == jbvArray)
return executeItemUnwrapTargetArray(cxt, jsp, jb, found, false);
else if (!jspIgnoreStructuralErrors(cxt))
{
Assert(found);
RETURN_ERROR(ereport(ERROR,
(errcode(ERRCODE_SQL_JSON_OBJECT_NOT_FOUND),
errmsg("jsonpath wildcard member accessor can only be applied to an object"))));
}
break;
case jpiAdd:
return executeBinaryArithmExpr(cxt, jsp, jb,
numeric_add_opt_error, found);
case jpiSub:
return executeBinaryArithmExpr(cxt, jsp, jb,
numeric_sub_opt_error, found);
case jpiMul:
return executeBinaryArithmExpr(cxt, jsp, jb,
numeric_mul_opt_error, found);
case jpiDiv:
return executeBinaryArithmExpr(cxt, jsp, jb,
numeric_div_opt_error, found);
case jpiMod:
return executeBinaryArithmExpr(cxt, jsp, jb,
numeric_mod_opt_error, found);
case jpiPlus:
return executeUnaryArithmExpr(cxt, jsp, jb, NULL, found);
case jpiMinus:
return executeUnaryArithmExpr(cxt, jsp, jb, numeric_uminus,
found);
case jpiFilter:
{
JsonPathBool st;
if (unwrap && JsonbType(jb) == jbvArray)
return executeItemUnwrapTargetArray(cxt, jsp, jb, found,
false);
jspGetArg(jsp, &elem);
st = executeNestedBoolItem(cxt, &elem, jb);
if (st != jpbTrue)
res = jperNotFound;
else
res = executeNextItem(cxt, jsp, NULL,
jb, found, true);
break;
}
case jpiAny:
{
bool hasNext = jspGetNext(jsp, &elem);
/* first try without any intermediate steps */
if (jsp->content.anybounds.first == 0)
{
bool savedIgnoreStructuralErrors;
savedIgnoreStructuralErrors = cxt->ignoreStructuralErrors;
cxt->ignoreStructuralErrors = true;
res = executeNextItem(cxt, jsp, &elem,
jb, found, true);
cxt->ignoreStructuralErrors = savedIgnoreStructuralErrors;
if (res == jperOk && !found)
break;
}
if (jb->type == jbvBinary)
res = executeAnyItem
(cxt, hasNext ? &elem : NULL,
jb->val.binary.data, found,
1,
jsp->content.anybounds.first,
jsp->content.anybounds.last,
true, jspAutoUnwrap(cxt));
break;
}
case jpiNull:
case jpiBool:
case jpiNumeric:
case jpiString:
case jpiVariable:
{
JsonbValue vbuf;
JsonbValue *v;
bool hasNext = jspGetNext(jsp, &elem);
if (!hasNext && !found)
{
res = jperOk; /* skip evaluation */
break;
}
v = hasNext ? &vbuf : palloc(sizeof(*v));
baseObject = cxt->baseObject;
getJsonPathItem(cxt, jsp, v);
res = executeNextItem(cxt, jsp, &elem,
v, found, hasNext);
cxt->baseObject = baseObject;
}
break;
case jpiType:
{
JsonbValue *jbv = palloc(sizeof(*jbv));
jbv->type = jbvString;
jbv->val.string.val = pstrdup(JsonbTypeName(jb));
jbv->val.string.len = strlen(jbv->val.string.val);
res = executeNextItem(cxt, jsp, NULL, jbv,
found, false);
}
break;
case jpiSize:
{
int size = JsonbArraySize(jb);
if (size < 0)
{
if (!jspAutoWrap(cxt))
{
if (!jspIgnoreStructuralErrors(cxt))
RETURN_ERROR(ereport(ERROR,
(errcode(ERRCODE_SQL_JSON_ARRAY_NOT_FOUND),
errmsg("jsonpath item method .%s() can only be applied to an array",
jspOperationName(jsp->type)))));
break;
}
size = 1;
}
jb = palloc(sizeof(*jb));
jb->type = jbvNumeric;
jb->val.numeric =
DatumGetNumeric(DirectFunctionCall1(int4_numeric,
Int32GetDatum(size)));
res = executeNextItem(cxt, jsp, NULL, jb, found, false);
}
break;
case jpiAbs:
return executeNumericItemMethod(cxt, jsp, jb, unwrap, numeric_abs,
found);
case jpiFloor:
return executeNumericItemMethod(cxt, jsp, jb, unwrap, numeric_floor,
found);
case jpiCeiling:
return executeNumericItemMethod(cxt, jsp, jb, unwrap, numeric_ceil,
found);
case jpiDouble:
{
JsonbValue jbv;
if (unwrap && JsonbType(jb) == jbvArray)
return executeItemUnwrapTargetArray(cxt, jsp, jb, found,
false);
if (jb->type == jbvNumeric)
{
char *tmp = DatumGetCString(DirectFunctionCall1(numeric_out,
NumericGetDatum(jb->val.numeric)));
bool have_error = false;
(void) float8in_internal_opt_error(tmp,
NULL,
"double precision",
tmp,
&have_error);
if (have_error)
RETURN_ERROR(ereport(ERROR,
(errcode(ERRCODE_NON_NUMERIC_SQL_JSON_ITEM),
errmsg("jsonpath item method .%s() can only be applied to a numeric value",
jspOperationName(jsp->type)))));
res = jperOk;
}
else if (jb->type == jbvString)
{
/* cast string as double */
double val;
char *tmp = pnstrdup(jb->val.string.val,
jb->val.string.len);
bool have_error = false;
val = float8in_internal_opt_error(tmp,
NULL,
"double precision",
tmp,
&have_error);
if (have_error || isinf(val))
RETURN_ERROR(ereport(ERROR,
(errcode(ERRCODE_NON_NUMERIC_SQL_JSON_ITEM),
errmsg("jsonpath item method .%s() can only be applied to a numeric value",
jspOperationName(jsp->type)))));
jb = &jbv;
jb->type = jbvNumeric;
jb->val.numeric = DatumGetNumeric(DirectFunctionCall1(float8_numeric,
Float8GetDatum(val)));
res = jperOk;
}
if (res == jperNotFound)
RETURN_ERROR(ereport(ERROR,
(errcode(ERRCODE_NON_NUMERIC_SQL_JSON_ITEM),
errmsg("jsonpath item method .%s() can only be applied to a string or numeric value",
jspOperationName(jsp->type)))));
res = executeNextItem(cxt, jsp, NULL, jb, found, true);
}
break;
case jpiKeyValue:
if (unwrap && JsonbType(jb) == jbvArray)
return executeItemUnwrapTargetArray(cxt, jsp, jb, found, false);
return executeKeyValueMethod(cxt, jsp, jb, found);
default:
elog(ERROR, "unrecognized jsonpath item type: %d", jsp->type);
}
return res;
}
/*
* Unwrap current array item and execute jsonpath for each of its elements.
*/
static JsonPathExecResult
executeItemUnwrapTargetArray(JsonPathExecContext *cxt, JsonPathItem *jsp,
JsonbValue *jb, JsonValueList *found,
bool unwrapElements)
{
if (jb->type != jbvBinary)
{
Assert(jb->type != jbvArray);
elog(ERROR, "invalid jsonb array value type: %d", jb->type);
}
return executeAnyItem
(cxt, jsp, jb->val.binary.data, found, 1, 1, 1,
false, unwrapElements);
}
/*
* Execute next jsonpath item if exists. Otherwise put "v" to the "found"
* list if provided.
*/
static JsonPathExecResult
executeNextItem(JsonPathExecContext *cxt,
JsonPathItem *cur, JsonPathItem *next,
JsonbValue *v, JsonValueList *found, bool copy)
{
JsonPathItem elem;
bool hasNext;
if (!cur)
hasNext = next != NULL;
else if (next)
hasNext = jspHasNext(cur);
else
{
next = &elem;
hasNext = jspGetNext(cur, next);
}
if (hasNext)
return executeItem(cxt, next, v, found);
if (found)
JsonValueListAppend(found, copy ? copyJsonbValue(v) : v);
return jperOk;
}
/*
* Same as executeItem(), but when "unwrap == true" automatically unwraps
* each array item from the resulting sequence in lax mode.
*/
static JsonPathExecResult
executeItemOptUnwrapResult(JsonPathExecContext *cxt, JsonPathItem *jsp,
JsonbValue *jb, bool unwrap,
JsonValueList *found)
{
if (unwrap && jspAutoUnwrap(cxt))
{
JsonValueList seq = {0};
JsonValueListIterator it;
JsonPathExecResult res = executeItem(cxt, jsp, jb, &seq);
JsonbValue *item;
if (jperIsError(res))
return res;
JsonValueListInitIterator(&seq, &it);
while ((item = JsonValueListNext(&seq, &it)))
{
Assert(item->type != jbvArray);
if (JsonbType(item) == jbvArray)
executeItemUnwrapTargetArray(cxt, NULL, item, found, false);
else
JsonValueListAppend(found, item);
}
return jperOk;
}
return executeItem(cxt, jsp, jb, found);
}
/*
* Same as executeItemOptUnwrapResult(), but with error suppression.
*/
static JsonPathExecResult
executeItemOptUnwrapResultNoThrow(JsonPathExecContext *cxt,
JsonPathItem *jsp,
JsonbValue *jb, bool unwrap,
JsonValueList *found)
{
JsonPathExecResult res;
bool throwErrors = cxt->throwErrors;
cxt->throwErrors = false;
res = executeItemOptUnwrapResult(cxt, jsp, jb, unwrap, found);
cxt->throwErrors = throwErrors;
return res;
}
/* Execute boolean-valued jsonpath expression. */
static JsonPathBool
executeBoolItem(JsonPathExecContext *cxt, JsonPathItem *jsp,
JsonbValue *jb, bool canHaveNext)
{
JsonPathItem larg;
JsonPathItem rarg;
JsonPathBool res;
JsonPathBool res2;
if (!canHaveNext && jspHasNext(jsp))
elog(ERROR, "boolean jsonpath item cannot have next item");
switch (jsp->type)
{
case jpiAnd:
jspGetLeftArg(jsp, &larg);
res = executeBoolItem(cxt, &larg, jb, false);
if (res == jpbFalse)
return jpbFalse;
/*
* SQL/JSON says that we should check second arg in case of
* jperError
*/
jspGetRightArg(jsp, &rarg);
res2 = executeBoolItem(cxt, &rarg, jb, false);
return res2 == jpbTrue ? res : res2;
case jpiOr:
jspGetLeftArg(jsp, &larg);
res = executeBoolItem(cxt, &larg, jb, false);
if (res == jpbTrue)
return jpbTrue;
jspGetRightArg(jsp, &rarg);
res2 = executeBoolItem(cxt, &rarg, jb, false);
return res2 == jpbFalse ? res : res2;
case jpiNot:
jspGetArg(jsp, &larg);
res = executeBoolItem(cxt, &larg, jb, false);
if (res == jpbUnknown)
return jpbUnknown;
return res == jpbTrue ? jpbFalse : jpbTrue;
case jpiIsUnknown:
jspGetArg(jsp, &larg);
res = executeBoolItem(cxt, &larg, jb, false);
return res == jpbUnknown ? jpbTrue : jpbFalse;
case jpiEqual:
case jpiNotEqual:
case jpiLess:
case jpiGreater:
case jpiLessOrEqual:
case jpiGreaterOrEqual:
jspGetLeftArg(jsp, &larg);
jspGetRightArg(jsp, &rarg);
return executePredicate(cxt, jsp, &larg, &rarg, jb, true,
executeComparison, NULL);
case jpiStartsWith: /* 'whole STARTS WITH initial' */
jspGetLeftArg(jsp, &larg); /* 'whole' */
jspGetRightArg(jsp, &rarg); /* 'initial' */
return executePredicate(cxt, jsp, &larg, &rarg, jb, false,
executeStartsWith, NULL);
case jpiLikeRegex: /* 'expr LIKE_REGEX pattern FLAGS flags' */
{
/*
* 'expr' is a sequence-returning expression. 'pattern' is a
* regex string literal. SQL/JSON standard requires XQuery
* regexes, but we use Postgres regexes here. 'flags' is a
* string literal converted to integer flags at compile-time.
*/
JsonLikeRegexContext lrcxt = {0};
jspInitByBuffer(&larg, jsp->base,
jsp->content.like_regex.expr);
return executePredicate(cxt, jsp, &larg, NULL, jb, false,
executeLikeRegex, &lrcxt);
}
case jpiExists:
jspGetArg(jsp, &larg);
if (jspStrictAbsenseOfErrors(cxt))
{
/*
* In strict mode we must get a complete list of values to
* check that there are no errors at all.
*/
JsonValueList vals = {0};
JsonPathExecResult res =
executeItemOptUnwrapResultNoThrow(cxt, &larg, jb,
false, &vals);
if (jperIsError(res))
return jpbUnknown;
return JsonValueListIsEmpty(&vals) ? jpbFalse : jpbTrue;
}
else
{
JsonPathExecResult res =
executeItemOptUnwrapResultNoThrow(cxt, &larg, jb,
false, NULL);
if (jperIsError(res))
return jpbUnknown;
return res == jperOk ? jpbTrue : jpbFalse;
}
default:
elog(ERROR, "invalid boolean jsonpath item type: %d", jsp->type);
return jpbUnknown;
}
}
/*
* Execute nested (filters etc.) boolean expression pushing current SQL/JSON
* item onto the stack.
*/
static JsonPathBool
executeNestedBoolItem(JsonPathExecContext *cxt, JsonPathItem *jsp,
JsonbValue *jb)
{
JsonbValue *prev;
JsonPathBool res;
prev = cxt->current;
cxt->current = jb;
res = executeBoolItem(cxt, jsp, jb, false);
cxt->current = prev;
return res;
}
/*
* Implementation of several jsonpath nodes:
* - jpiAny (.** accessor),
* - jpiAnyKey (.* accessor),
* - jpiAnyArray ([*] accessor)
*/
static JsonPathExecResult
executeAnyItem(JsonPathExecContext *cxt, JsonPathItem *jsp, JsonbContainer *jbc,
JsonValueList *found, uint32 level, uint32 first, uint32 last,
bool ignoreStructuralErrors, bool unwrapNext)
{
JsonPathExecResult res = jperNotFound;
JsonbIterator *it;
int32 r;
JsonbValue v;
check_stack_depth();
if (level > last)
return res;
it = JsonbIteratorInit(jbc);
/*
* Recursively iterate over jsonb objects/arrays
*/
while ((r = JsonbIteratorNext(&it, &v, true)) != WJB_DONE)
{
if (r == WJB_KEY)
{
r = JsonbIteratorNext(&it, &v, true);
Assert(r == WJB_VALUE);
}
if (r == WJB_VALUE || r == WJB_ELEM)
{
if (level >= first ||
(first == PG_UINT32_MAX && last == PG_UINT32_MAX &&
v.type != jbvBinary)) /* leaves only requested */
{
/* check expression */
if (jsp)
{
if (ignoreStructuralErrors)
{
bool savedIgnoreStructuralErrors;
savedIgnoreStructuralErrors = cxt->ignoreStructuralErrors;
cxt->ignoreStructuralErrors = true;
res = executeItemOptUnwrapTarget(cxt, jsp, &v, found, unwrapNext);
cxt->ignoreStructuralErrors = savedIgnoreStructuralErrors;
}
else
res = executeItemOptUnwrapTarget(cxt, jsp, &v, found, unwrapNext);
if (jperIsError(res))
break;
if (res == jperOk && !found)
break;
}
else if (found)
JsonValueListAppend(found, copyJsonbValue(&v));
else
return jperOk;
}
if (level < last && v.type == jbvBinary)
{
res = executeAnyItem
(cxt, jsp, v.val.binary.data, found,
level + 1, first, last,
ignoreStructuralErrors, unwrapNext);
if (jperIsError(res))
break;
if (res == jperOk && found == NULL)
break;
}
}
}
return res;
}
/*
* Execute unary or binary predicate.
*
* Predicates have existence semantics, because their operands are item
* sequences. Pairs of items from the left and right operand's sequences are
* checked. TRUE returned only if any pair satisfying the condition is found.
* In strict mode, even if the desired pair has already been found, all pairs
* still need to be examined to check the absence of errors. If any error
* occurs, UNKNOWN (analogous to SQL NULL) is returned.
*/
static JsonPathBool
executePredicate(JsonPathExecContext *cxt, JsonPathItem *pred,
JsonPathItem *larg, JsonPathItem *rarg, JsonbValue *jb,
bool unwrapRightArg, JsonPathPredicateCallback exec,
void *param)
{
JsonPathExecResult res;
JsonValueListIterator lseqit;
JsonValueList lseq = {0};
JsonValueList rseq = {0};
JsonbValue *lval;
bool error = false;
bool found = false;
/* Left argument is always auto-unwrapped. */
res = executeItemOptUnwrapResultNoThrow(cxt, larg, jb, true, &lseq);
if (jperIsError(res))
return jpbUnknown;
if (rarg)
{
/* Right argument is conditionally auto-unwrapped. */
res = executeItemOptUnwrapResultNoThrow(cxt, rarg, jb,
unwrapRightArg, &rseq);
if (jperIsError(res))
return jpbUnknown;
}
JsonValueListInitIterator(&lseq, &lseqit);
while ((lval = JsonValueListNext(&lseq, &lseqit)))
{
JsonValueListIterator rseqit;
JsonbValue *rval;
bool first = true;
JsonValueListInitIterator(&rseq, &rseqit);
if (rarg)
rval = JsonValueListNext(&rseq, &rseqit);
else
rval = NULL;
/* Loop over right arg sequence or do single pass otherwise */
while (rarg ? (rval != NULL) : first)
{
JsonPathBool res = exec(pred, lval, rval, param);
if (res == jpbUnknown)
{
if (jspStrictAbsenseOfErrors(cxt))
return jpbUnknown;
error = true;
}
else if (res == jpbTrue)
{
if (!jspStrictAbsenseOfErrors(cxt))
return jpbTrue;
found = true;
}
first = false;
if (rarg)
rval = JsonValueListNext(&rseq, &rseqit);
}
}
if (found) /* possible only in strict mode */
return jpbTrue;
if (error) /* possible only in lax mode */
return jpbUnknown;
return jpbFalse;
}
/*
* Execute binary arithmetic expression on singleton numeric operands.
* Array operands are automatically unwrapped in lax mode.
*/
static JsonPathExecResult
executeBinaryArithmExpr(JsonPathExecContext *cxt, JsonPathItem *jsp,
JsonbValue *jb, BinaryArithmFunc func,
JsonValueList *found)
{
JsonPathExecResult jper;
JsonPathItem elem;
JsonValueList lseq = {0};
JsonValueList rseq = {0};
JsonbValue *lval;
JsonbValue *rval;
Numeric res;
jspGetLeftArg(jsp, &elem);
/*
* XXX: By standard only operands of multiplicative expressions are
* unwrapped. We extend it to other binary arithmetic expressions too.
*/
jper = executeItemOptUnwrapResult(cxt, &elem, jb, true, &lseq);
if (jperIsError(jper))
return jper;
jspGetRightArg(jsp, &elem);
jper = executeItemOptUnwrapResult(cxt, &elem, jb, true, &rseq);
if (jperIsError(jper))
return jper;
if (JsonValueListLength(&lseq) != 1 ||
!(lval = getScalar(JsonValueListHead(&lseq), jbvNumeric)))
RETURN_ERROR(ereport(ERROR,
(errcode(ERRCODE_SINGLETON_SQL_JSON_ITEM_REQUIRED),
errmsg("left operand of jsonpath operator %s is not a single numeric value",
jspOperationName(jsp->type)))));
if (JsonValueListLength(&rseq) != 1 ||
!(rval = getScalar(JsonValueListHead(&rseq), jbvNumeric)))
RETURN_ERROR(ereport(ERROR,
(errcode(ERRCODE_SINGLETON_SQL_JSON_ITEM_REQUIRED),
errmsg("right operand of jsonpath operator %s is not a single numeric value",
jspOperationName(jsp->type)))));
if (jspThrowErrors(cxt))
{
res = func(lval->val.numeric, rval->val.numeric, NULL);
}
else
{
bool error = false;
res = func(lval->val.numeric, rval->val.numeric, &error);
if (error)
return jperError;
}
if (!jspGetNext(jsp, &elem) && !found)
return jperOk;
lval = palloc(sizeof(*lval));
lval->type = jbvNumeric;
lval->val.numeric = res;
return executeNextItem(cxt, jsp, &elem, lval, found, false);
}
/*
* Execute unary arithmetic expression for each numeric item in its operand's
* sequence. Array operand is automatically unwrapped in lax mode.
*/
static JsonPathExecResult
executeUnaryArithmExpr(JsonPathExecContext *cxt, JsonPathItem *jsp,
JsonbValue *jb, PGFunction func, JsonValueList *found)
{
JsonPathExecResult jper;
JsonPathExecResult jper2;
JsonPathItem elem;
JsonValueList seq = {0};
JsonValueListIterator it;
JsonbValue *val;
bool hasNext;
jspGetArg(jsp, &elem);
jper = executeItemOptUnwrapResult(cxt, &elem, jb, true, &seq);
if (jperIsError(jper))
return jper;
jper = jperNotFound;
hasNext = jspGetNext(jsp, &elem);
JsonValueListInitIterator(&seq, &it);
while ((val = JsonValueListNext(&seq, &it)))
{
if ((val = getScalar(val, jbvNumeric)))
{
if (!found && !hasNext)
return jperOk;
}
else
{
if (!found && !hasNext)
continue; /* skip non-numerics processing */
RETURN_ERROR(ereport(ERROR,
(errcode(ERRCODE_SQL_JSON_NUMBER_NOT_FOUND),
errmsg("operand of unary jsonpath operator %s is not a numeric value",
jspOperationName(jsp->type)))));
}
if (func)
val->val.numeric =
DatumGetNumeric(DirectFunctionCall1(func,
NumericGetDatum(val->val.numeric)));
jper2 = executeNextItem(cxt, jsp, &elem, val, found, false);
if (jperIsError(jper2))
return jper2;
if (jper2 == jperOk)
{
if (!found)
return jperOk;
jper = jperOk;
}
}
return jper;
}
/*
* STARTS_WITH predicate callback.
*
* Check if the 'whole' string starts from 'initial' string.
*/
static JsonPathBool
executeStartsWith(JsonPathItem *jsp, JsonbValue *whole, JsonbValue *initial,
void *param)
{
if (!(whole = getScalar(whole, jbvString)))
return jpbUnknown; /* error */
if (!(initial = getScalar(initial, jbvString)))
return jpbUnknown; /* error */
if (whole->val.string.len >= initial->val.string.len &&
!memcmp(whole->val.string.val,
initial->val.string.val,
initial->val.string.len))
return jpbTrue;
return jpbFalse;
}
/*
* LIKE_REGEX predicate callback.
*
* Check if the string matches regex pattern.
*/
static JsonPathBool
executeLikeRegex(JsonPathItem *jsp, JsonbValue *str, JsonbValue *rarg,
void *param)
{
JsonLikeRegexContext *cxt = param;
if (!(str = getScalar(str, jbvString)))
return jpbUnknown;
/* Cache regex text and converted flags. */
if (!cxt->regex)
{
uint32 flags = jsp->content.like_regex.flags;
cxt->regex =
cstring_to_text_with_len(jsp->content.like_regex.pattern,
jsp->content.like_regex.patternlen);
/* Convert regex flags. */
cxt->cflags = REG_ADVANCED;
if (flags & JSP_REGEX_ICASE)
cxt->cflags |= REG_ICASE;
if (flags & JSP_REGEX_MLINE)
cxt->cflags |= REG_NEWLINE;
if (flags & JSP_REGEX_SLINE)
cxt->cflags &= ~REG_NEWLINE;
if (flags & JSP_REGEX_WSPACE)
cxt->cflags |= REG_EXPANDED;
/*
* 'q' flag can work together only with 'i'. When other is specified,
* then 'q' has no effect.
*/
if ((flags & JSP_REGEX_QUOTE) &&
!(flags & (JSP_REGEX_MLINE | JSP_REGEX_SLINE | JSP_REGEX_WSPACE)))
{
cxt->cflags &= ~REG_ADVANCED;
cxt->cflags |= REG_QUOTE;
}
}
if (RE_compile_and_execute(cxt->regex, str->val.string.val,
str->val.string.len,
cxt->cflags, DEFAULT_COLLATION_OID, 0, NULL))
return jpbTrue;
return jpbFalse;
}
/*
* Execute numeric item methods (.abs(), .floor(), .ceil()) using the specified
* user function 'func'.
*/
static JsonPathExecResult
executeNumericItemMethod(JsonPathExecContext *cxt, JsonPathItem *jsp,
JsonbValue *jb, bool unwrap, PGFunction func,
JsonValueList *found)
{
JsonPathItem next;
Datum datum;
if (unwrap && JsonbType(jb) == jbvArray)
return executeItemUnwrapTargetArray(cxt, jsp, jb, found, false);
if (!(jb = getScalar(jb, jbvNumeric)))
RETURN_ERROR(ereport(ERROR,
(errcode(ERRCODE_NON_NUMERIC_SQL_JSON_ITEM),
errmsg("jsonpath item method .%s() can only be applied to a numeric value",
jspOperationName(jsp->type)))));
datum = DirectFunctionCall1(func, NumericGetDatum(jb->val.numeric));
if (!jspGetNext(jsp, &next) && !found)
return jperOk;
jb = palloc(sizeof(*jb));
jb->type = jbvNumeric;
jb->val.numeric = DatumGetNumeric(datum);
return executeNextItem(cxt, jsp, &next, jb, found, false);
}
/*
* Implementation of .keyvalue() method.
*
* .keyvalue() method returns a sequence of object's key-value pairs in the
* following format: '{ "key": key, "value": value, "id": id }'.
*
* "id" field is an object identifier which is constructed from the two parts:
* base object id and its binary offset in base object's jsonb:
* id = 10000000000 * base_object_id + obj_offset_in_base_object
*
* 10000000000 (10^10) -- is a first round decimal number greater than 2^32
* (maximal offset in jsonb). Decimal multiplier is used here to improve the
* readability of identifiers.
*
* Base object is usually a root object of the path: context item '$' or path
* variable '$var', literals can't produce objects for now. But if the path
* contains generated objects (.keyvalue() itself, for example), then they
* become base object for the subsequent .keyvalue().
*
* Id of '$' is 0. Id of '$var' is its ordinal (positive) number in the list
* of variables (see getJsonPathVariable()). Ids for generated objects
* are assigned using global counter JsonPathExecContext.lastGeneratedObjectId.
*/
static JsonPathExecResult
executeKeyValueMethod(JsonPathExecContext *cxt, JsonPathItem *jsp,
JsonbValue *jb, JsonValueList *found)
{
JsonPathExecResult res = jperNotFound;
JsonPathItem next;
JsonbContainer *jbc;
JsonbValue key;
JsonbValue val;
JsonbValue idval;
JsonbValue keystr;
JsonbValue valstr;
JsonbValue idstr;
JsonbIterator *it;
JsonbIteratorToken tok;
int64 id;
bool hasNext;
if (JsonbType(jb) != jbvObject || jb->type != jbvBinary)
RETURN_ERROR(ereport(ERROR,
(errcode(ERRCODE_SQL_JSON_OBJECT_NOT_FOUND),
errmsg("jsonpath item method .%s() can only be applied to an object",
jspOperationName(jsp->type)))));
jbc = jb->val.binary.data;
if (!JsonContainerSize(jbc))
return jperNotFound; /* no key-value pairs */
hasNext = jspGetNext(jsp, &next);
keystr.type = jbvString;
keystr.val.string.val = "key";
keystr.val.string.len = 3;
valstr.type = jbvString;
valstr.val.string.val = "value";
valstr.val.string.len = 5;
idstr.type = jbvString;
idstr.val.string.val = "id";
idstr.val.string.len = 2;
/* construct object id from its base object and offset inside that */
id = jb->type != jbvBinary ? 0 :
(int64) ((char *) jbc - (char *) cxt->baseObject.jbc);
id += (int64) cxt->baseObject.id * INT64CONST(10000000000);
idval.type = jbvNumeric;
idval.val.numeric = DatumGetNumeric(DirectFunctionCall1(int8_numeric,
Int64GetDatum(id)));
it = JsonbIteratorInit(jbc);
while ((tok = JsonbIteratorNext(&it, &key, true)) != WJB_DONE)
{
JsonBaseObjectInfo baseObject;
JsonbValue obj;
JsonbParseState *ps;
JsonbValue *keyval;
Jsonb *jsonb;
if (tok != WJB_KEY)
continue;
res = jperOk;
if (!hasNext && !found)
break;
tok = JsonbIteratorNext(&it, &val, true);
Assert(tok == WJB_VALUE);
ps = NULL;
pushJsonbValue(&ps, WJB_BEGIN_OBJECT, NULL);
pushJsonbValue(&ps, WJB_KEY, &keystr);
pushJsonbValue(&ps, WJB_VALUE, &key);
pushJsonbValue(&ps, WJB_KEY, &valstr);
pushJsonbValue(&ps, WJB_VALUE, &val);
pushJsonbValue(&ps, WJB_KEY, &idstr);
pushJsonbValue(&ps, WJB_VALUE, &idval);
keyval = pushJsonbValue(&ps, WJB_END_OBJECT, NULL);
jsonb = JsonbValueToJsonb(keyval);
JsonbInitBinary(&obj, jsonb);
baseObject = setBaseObject(cxt, &obj, cxt->lastGeneratedObjectId++);
res = executeNextItem(cxt, jsp, &next, &obj, found, true);
cxt->baseObject = baseObject;
if (jperIsError(res))
return res;
if (res == jperOk && !found)
break;
}
return res;
}
/*
* Convert boolean execution status 'res' to a boolean JSON item and execute
* next jsonpath.
*/
static JsonPathExecResult
appendBoolResult(JsonPathExecContext *cxt, JsonPathItem *jsp,
JsonValueList *found, JsonPathBool res)
{
JsonPathItem next;
JsonbValue jbv;
if (!jspGetNext(jsp, &next) && !found)
return jperOk; /* found singleton boolean value */
if (res == jpbUnknown)
{
jbv.type = jbvNull;
}
else
{
jbv.type = jbvBool;
jbv.val.boolean = res == jpbTrue;
}
return executeNextItem(cxt, jsp, &next, &jbv, found, true);
}
/*
* Convert jsonpath's scalar or variable node to actual jsonb value.
*
* If node is a variable then its id returned, otherwise 0 returned.
*/
static void
getJsonPathItem(JsonPathExecContext *cxt, JsonPathItem *item,
JsonbValue *value)
{
switch (item->type)
{
case jpiNull:
value->type = jbvNull;
break;
case jpiBool:
value->type = jbvBool;
value->val.boolean = jspGetBool(item);
break;
case jpiNumeric:
value->type = jbvNumeric;
value->val.numeric = jspGetNumeric(item);
break;
case jpiString:
value->type = jbvString;
value->val.string.val = jspGetString(item,
&value->val.string.len);
break;
case jpiVariable:
getJsonPathVariable(cxt, item, cxt->vars, value);
return;
default:
elog(ERROR, "unexpected jsonpath item type");
}
}
/*
* Get the value of variable passed to jsonpath executor
*/
static void
getJsonPathVariable(JsonPathExecContext *cxt, JsonPathItem *variable,
Jsonb *vars, JsonbValue *value)
{
char *varName;
int varNameLength;
JsonbValue tmp;
JsonbValue *v;
if (!vars)
{
value->type = jbvNull;
return;
}
Assert(variable->type == jpiVariable);
varName = jspGetString(variable, &varNameLength);
tmp.type = jbvString;
tmp.val.string.val = varName;
tmp.val.string.len = varNameLength;
v = findJsonbValueFromContainer(&vars->root, JB_FOBJECT, &tmp);
if (v)
{
*value = *v;
pfree(v);
}
else
{
ereport(ERROR,
(errcode(ERRCODE_UNDEFINED_OBJECT),
errmsg("could not find jsonpath variable \"%s\"",
pnstrdup(varName, varNameLength))));
}
JsonbInitBinary(&tmp, vars);
setBaseObject(cxt, &tmp, 1);
}
/**************** Support functions for JsonPath execution *****************/
/*
* Returns the size of an array item, or -1 if item is not an array.
*/
static int
JsonbArraySize(JsonbValue *jb)
{
Assert(jb->type != jbvArray);
if (jb->type == jbvBinary)
{
JsonbContainer *jbc = jb->val.binary.data;
if (JsonContainerIsArray(jbc) && !JsonContainerIsScalar(jbc))
return JsonContainerSize(jbc);
}
return -1;
}
/* Comparison predicate callback. */
static JsonPathBool
executeComparison(JsonPathItem *cmp, JsonbValue *lv, JsonbValue *rv, void *p)
{
return compareItems(cmp->type, lv, rv);
}
/*
* Perform per-byte comparison of two strings.
*/
static int
binaryCompareStrings(const char *s1, int len1,
const char *s2, int len2)
{
int cmp;
cmp = memcmp(s1, s2, Min(len1, len2));
if (cmp != 0)
return cmp;
if (len1 == len2)
return 0;
return len1 < len2 ? -1 : 1;
}
/*
* Compare two strings in the current server encoding using Unicode codepoint
* collation.
*/
static int
compareStrings(const char *mbstr1, int mblen1,
const char *mbstr2, int mblen2)
{
if (GetDatabaseEncoding() == PG_SQL_ASCII ||
GetDatabaseEncoding() == PG_UTF8)
{
/*
* It's known property of UTF-8 strings that their per-byte comparison
* result matches codepoints comparison result. ASCII can be
* considered as special case of UTF-8.
*/
return binaryCompareStrings(mbstr1, mblen1, mbstr2, mblen2);
}
else
{
char *utf8str1,
*utf8str2;
int cmp,
utf8len1,
utf8len2;
/*
* We have to convert other encodings to UTF-8 first, then compare.
* Input strings may be not null-terminated and pg_server_to_any() may
* return them "as is". So, use strlen() only if there is real
* conversion.
*/
utf8str1 = pg_server_to_any(mbstr1, mblen1, PG_UTF8);
utf8str2 = pg_server_to_any(mbstr2, mblen2, PG_UTF8);
utf8len1 = (mbstr1 == utf8str1) ? mblen1 : strlen(utf8str1);
utf8len2 = (mbstr2 == utf8str2) ? mblen2 : strlen(utf8str2);
cmp = binaryCompareStrings(utf8str1, utf8len1, utf8str2, utf8len2);
/*
* If pg_server_to_any() did no real conversion, then we actually
* compared original strings. So, we already done.
*/
if (mbstr1 == utf8str1 && mbstr2 == utf8str2)
return cmp;
/* Free memory if needed */
if (mbstr1 != utf8str1)
pfree(utf8str1);
if (mbstr2 != utf8str2)
pfree(utf8str2);
/*
* When all Unicode codepoints are equal, return result of binary
* comparison. In some edge cases, same characters may have different
* representations in encoding. Then our behavior could diverge from
* standard. However, that allow us to do simple binary comparison
* for "==" operator, which is performance critical in typical cases.
* In future to implement strict standard conformance, we can do
* normalization of input JSON strings.
*/
if (cmp == 0)
return binaryCompareStrings(mbstr1, mblen1, mbstr2, mblen2);
else
return cmp;
}
}
/*
* Compare two SQL/JSON items using comparison operation 'op'.
*/
static JsonPathBool
compareItems(int32 op, JsonbValue *jb1, JsonbValue *jb2)
{
int cmp;
bool res;
if (jb1->type != jb2->type)
{
if (jb1->type == jbvNull || jb2->type == jbvNull)
/*
* Equality and order comparison of nulls to non-nulls returns
* always false, but inequality comparison returns true.
*/
return op == jpiNotEqual ? jpbTrue : jpbFalse;
/* Non-null items of different types are not comparable. */
return jpbUnknown;
}
switch (jb1->type)
{
case jbvNull:
cmp = 0;
break;
case jbvBool:
cmp = jb1->val.boolean == jb2->val.boolean ? 0 :
jb1->val.boolean ? 1 : -1;
break;
case jbvNumeric:
cmp = compareNumeric(jb1->val.numeric, jb2->val.numeric);
break;
case jbvString:
if (op == jpiEqual)
return jb1->val.string.len != jb2->val.string.len ||
memcmp(jb1->val.string.val,
jb2->val.string.val,
jb1->val.string.len) ? jpbFalse : jpbTrue;
cmp = compareStrings(jb1->val.string.val, jb1->val.string.len,
jb2->val.string.val, jb2->val.string.len);
break;
case jbvBinary:
case jbvArray:
case jbvObject:
return jpbUnknown; /* non-scalars are not comparable */
default:
elog(ERROR, "invalid jsonb value type %d", jb1->type);
}
switch (op)
{
case jpiEqual:
res = (cmp == 0);
break;
case jpiNotEqual:
res = (cmp != 0);
break;
case jpiLess:
res = (cmp < 0);
break;
case jpiGreater:
res = (cmp > 0);
break;
case jpiLessOrEqual:
res = (cmp <= 0);
break;
case jpiGreaterOrEqual:
res = (cmp >= 0);
break;
default:
elog(ERROR, "unrecognized jsonpath operation: %d", op);
return jpbUnknown;
}
return res ? jpbTrue : jpbFalse;
}
/* Compare two numerics */
static int
compareNumeric(Numeric a, Numeric b)
{
return DatumGetInt32(DirectFunctionCall2(numeric_cmp,
NumericGetDatum(a),
NumericGetDatum(b)));
}
static JsonbValue *
copyJsonbValue(JsonbValue *src)
{
JsonbValue *dst = palloc(sizeof(*dst));
*dst = *src;
return dst;
}
/*
* Execute array subscript expression and convert resulting numeric item to
* the integer type with truncation.
*/
static JsonPathExecResult
getArrayIndex(JsonPathExecContext *cxt, JsonPathItem *jsp, JsonbValue *jb,
int32 *index)
{
JsonbValue *jbv;
JsonValueList found = {0};
JsonPathExecResult res = executeItem(cxt, jsp, jb, &found);
Datum numeric_index;
bool have_error = false;
if (jperIsError(res))
return res;
if (JsonValueListLength(&found) != 1 ||
!(jbv = getScalar(JsonValueListHead(&found), jbvNumeric)))
RETURN_ERROR(ereport(ERROR,
(errcode(ERRCODE_INVALID_SQL_JSON_SUBSCRIPT),
errmsg("jsonpath array subscript is not a single numeric value"))));
numeric_index = DirectFunctionCall2(numeric_trunc,
NumericGetDatum(jbv->val.numeric),
Int32GetDatum(0));
*index = numeric_int4_opt_error(DatumGetNumeric(numeric_index),
&have_error);
if (have_error)
RETURN_ERROR(ereport(ERROR,
(errcode(ERRCODE_INVALID_SQL_JSON_SUBSCRIPT),
errmsg("jsonpath array subscript is out of integer range"))));
return jperOk;
}
/* Save base object and its id needed for the execution of .keyvalue(). */
static JsonBaseObjectInfo
setBaseObject(JsonPathExecContext *cxt, JsonbValue *jbv, int32 id)
{
JsonBaseObjectInfo baseObject = cxt->baseObject;
cxt->baseObject.jbc = jbv->type != jbvBinary ? NULL :
(JsonbContainer *) jbv->val.binary.data;
cxt->baseObject.id = id;
return baseObject;
}
static void
JsonValueListAppend(JsonValueList *jvl, JsonbValue *jbv)
{
if (jvl->singleton)
{
jvl->list = list_make2(jvl->singleton, jbv);
jvl->singleton = NULL;
}
else if (!jvl->list)
jvl->singleton = jbv;
else
jvl->list = lappend(jvl->list, jbv);
}
static int
JsonValueListLength(const JsonValueList *jvl)
{
return jvl->singleton ? 1 : list_length(jvl->list);
}
static bool
JsonValueListIsEmpty(JsonValueList *jvl)
{
return !jvl->singleton && list_length(jvl->list) <= 0;
}
static JsonbValue *
JsonValueListHead(JsonValueList *jvl)
{
return jvl->singleton ? jvl->singleton : linitial(jvl->list);
}
static List *
JsonValueListGetList(JsonValueList *jvl)
{
if (jvl->singleton)
return list_make1(jvl->singleton);
return jvl->list;
}
static void
JsonValueListInitIterator(const JsonValueList *jvl, JsonValueListIterator *it)
{
if (jvl->singleton)
{
it->value = jvl->singleton;
it->list = NIL;
it->next = NULL;
}
else if (jvl->list != NIL)
{
it->value = (JsonbValue *) linitial(jvl->list);
it->list = jvl->list;
it->next = list_second_cell(jvl->list);
}
else
{
it->value = NULL;
it->list = NIL;
it->next = NULL;
}
}
/*
* Get the next item from the sequence advancing iterator.
*/
static JsonbValue *
JsonValueListNext(const JsonValueList *jvl, JsonValueListIterator *it)
{
JsonbValue *result = it->value;
if (it->next)
{
it->value = lfirst(it->next);
it->next = lnext(it->list, it->next);
}
else
{
it->value = NULL;
}
return result;
}
/*
* Initialize a binary JsonbValue with the given jsonb container.
*/
static JsonbValue *
JsonbInitBinary(JsonbValue *jbv, Jsonb *jb)
{
jbv->type = jbvBinary;
jbv->val.binary.data = &jb->root;
jbv->val.binary.len = VARSIZE_ANY_EXHDR(jb);
return jbv;
}
/*
* Returns jbv* type of of JsonbValue. Note, it never returns jbvBinary as is.
*/
static int
JsonbType(JsonbValue *jb)
{
int type = jb->type;
if (jb->type == jbvBinary)
{
JsonbContainer *jbc = (void *) jb->val.binary.data;
/* Scalars should be always extracted during jsonpath execution. */
Assert(!JsonContainerIsScalar(jbc));
if (JsonContainerIsObject(jbc))
type = jbvObject;
else if (JsonContainerIsArray(jbc))
type = jbvArray;
else
elog(ERROR, "invalid jsonb container type: 0x%08x", jbc->header);
}
return type;
}
/* Get scalar of given type or NULL on type mismatch */
static JsonbValue *
getScalar(JsonbValue *scalar, enum jbvType type)
{
/* Scalars should be always extracted during jsonpath execution. */
Assert(scalar->type != jbvBinary ||
!JsonContainerIsScalar(scalar->val.binary.data));
return scalar->type == type ? scalar : NULL;
}
/* Construct a JSON array from the item list */
static JsonbValue *
wrapItemsInArray(const JsonValueList *items)
{
JsonbParseState *ps = NULL;
JsonValueListIterator it;
JsonbValue *jbv;
pushJsonbValue(&ps, WJB_BEGIN_ARRAY, NULL);
JsonValueListInitIterator(items, &it);
while ((jbv = JsonValueListNext(items, &it)))
pushJsonbValue(&ps, WJB_ELEM, jbv);
return pushJsonbValue(&ps, WJB_END_ARRAY, NULL);
}
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