mirror of
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f41042cea0
This reverts commit 54547bd87f49326d67051254c363e6597d16ffda. This appears to have been a thinko on my part. I will try to come up wioth a better solution.
1805 lines
50 KiB
C
1805 lines
50 KiB
C
/*-------------------------------------------------------------------------
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*
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* jsonb_util.c
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* converting between Jsonb and JsonbValues, and iterating.
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*
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* Copyright (c) 2014-2015, PostgreSQL Global Development Group
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*
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*
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* IDENTIFICATION
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* src/backend/utils/adt/jsonb_util.c
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*
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*-------------------------------------------------------------------------
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*/
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#include "postgres.h"
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#include "access/hash.h"
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#include "catalog/pg_collation.h"
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#include "miscadmin.h"
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#include "utils/builtins.h"
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#include "utils/jsonb.h"
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#include "utils/memutils.h"
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/*
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* Maximum number of elements in an array (or key/value pairs in an object).
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* This is limited by two things: the size of the JEntry array must fit
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* in MaxAllocSize, and the number of elements (or pairs) must fit in the bits
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* reserved for that in the JsonbContainer.header field.
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*
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* (The total size of an array's or object's elements is also limited by
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* JENTRY_OFFLENMASK, but we're not concerned about that here.)
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*/
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#define JSONB_MAX_ELEMS (Min(MaxAllocSize / sizeof(JsonbValue), JB_CMASK))
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#define JSONB_MAX_PAIRS (Min(MaxAllocSize / sizeof(JsonbPair), JB_CMASK))
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static void fillJsonbValue(JsonbContainer *container, int index,
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char *base_addr, uint32 offset,
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JsonbValue *result);
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static bool equalsJsonbScalarValue(JsonbValue *a, JsonbValue *b);
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static int compareJsonbScalarValue(JsonbValue *a, JsonbValue *b);
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static Jsonb *convertToJsonb(JsonbValue *val);
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static void convertJsonbValue(StringInfo buffer, JEntry *header, JsonbValue *val, int level);
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static void convertJsonbArray(StringInfo buffer, JEntry *header, JsonbValue *val, int level);
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static void convertJsonbObject(StringInfo buffer, JEntry *header, JsonbValue *val, int level);
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static void convertJsonbScalar(StringInfo buffer, JEntry *header, JsonbValue *scalarVal);
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static int reserveFromBuffer(StringInfo buffer, int len);
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static void appendToBuffer(StringInfo buffer, const char *data, int len);
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static void copyToBuffer(StringInfo buffer, int offset, const char *data, int len);
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static short padBufferToInt(StringInfo buffer);
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static JsonbIterator *iteratorFromContainer(JsonbContainer *container, JsonbIterator *parent);
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static JsonbIterator *freeAndGetParent(JsonbIterator *it);
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static JsonbParseState *pushState(JsonbParseState **pstate);
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static void appendKey(JsonbParseState *pstate, JsonbValue *scalarVal);
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static void appendValue(JsonbParseState *pstate, JsonbValue *scalarVal);
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static void appendElement(JsonbParseState *pstate, JsonbValue *scalarVal);
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static int lengthCompareJsonbStringValue(const void *a, const void *b);
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static int lengthCompareJsonbPair(const void *a, const void *b, void *arg);
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static void uniqueifyJsonbObject(JsonbValue *object);
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static JsonbValue *pushJsonbValueScalar(JsonbParseState **pstate,
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JsonbIteratorToken seq,
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JsonbValue *scalarVal);
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/*
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* Turn an in-memory JsonbValue into a Jsonb for on-disk storage.
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*
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* There isn't a JsonbToJsonbValue(), because generally we find it more
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* convenient to directly iterate through the Jsonb representation and only
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* really convert nested scalar values. JsonbIteratorNext() does this, so that
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* clients of the iteration code don't have to directly deal with the binary
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* representation (JsonbDeepContains() is a notable exception, although all
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* exceptions are internal to this module). In general, functions that accept
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* a JsonbValue argument are concerned with the manipulation of scalar values,
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* or simple containers of scalar values, where it would be inconvenient to
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* deal with a great amount of other state.
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*/
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Jsonb *
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JsonbValueToJsonb(JsonbValue *val)
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{
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Jsonb *out;
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if (IsAJsonbScalar(val))
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{
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/* Scalar value */
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JsonbParseState *pstate = NULL;
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JsonbValue *res;
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JsonbValue scalarArray;
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scalarArray.type = jbvArray;
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scalarArray.val.array.rawScalar = true;
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scalarArray.val.array.nElems = 1;
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pushJsonbValue(&pstate, WJB_BEGIN_ARRAY, &scalarArray);
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pushJsonbValue(&pstate, WJB_ELEM, val);
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res = pushJsonbValue(&pstate, WJB_END_ARRAY, NULL);
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out = convertToJsonb(res);
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}
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else if (val->type == jbvObject || val->type == jbvArray)
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{
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out = convertToJsonb(val);
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}
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else
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{
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Assert(val->type == jbvBinary);
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out = palloc(VARHDRSZ + val->val.binary.len);
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SET_VARSIZE(out, VARHDRSZ + val->val.binary.len);
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memcpy(VARDATA(out), val->val.binary.data, val->val.binary.len);
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}
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return out;
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}
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/*
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* Get the offset of the variable-length portion of a Jsonb node within
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* the variable-length-data part of its container. The node is identified
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* by index within the container's JEntry array.
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*/
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uint32
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getJsonbOffset(const JsonbContainer *jc, int index)
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{
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uint32 offset = 0;
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int i;
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/*
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* Start offset of this entry is equal to the end offset of the previous
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* entry. Walk backwards to the most recent entry stored as an end
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* offset, returning that offset plus any lengths in between.
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*/
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for (i = index - 1; i >= 0; i--)
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{
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offset += JBE_OFFLENFLD(jc->children[i]);
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if (JBE_HAS_OFF(jc->children[i]))
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break;
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}
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return offset;
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}
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/*
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* Get the length of the variable-length portion of a Jsonb node.
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* The node is identified by index within the container's JEntry array.
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*/
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uint32
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getJsonbLength(const JsonbContainer *jc, int index)
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{
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uint32 off;
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uint32 len;
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/*
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* If the length is stored directly in the JEntry, just return it.
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* Otherwise, get the begin offset of the entry, and subtract that from
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* the stored end+1 offset.
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*/
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if (JBE_HAS_OFF(jc->children[index]))
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{
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off = getJsonbOffset(jc, index);
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len = JBE_OFFLENFLD(jc->children[index]) - off;
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}
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else
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len = JBE_OFFLENFLD(jc->children[index]);
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return len;
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}
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/*
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* BT comparator worker function. Returns an integer less than, equal to, or
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* greater than zero, indicating whether a is less than, equal to, or greater
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* than b. Consistent with the requirements for a B-Tree operator class
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*
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* Strings are compared lexically, in contrast with other places where we use a
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* much simpler comparator logic for searching through Strings. Since this is
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* called from B-Tree support function 1, we're careful about not leaking
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* memory here.
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*/
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int
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compareJsonbContainers(JsonbContainer *a, JsonbContainer *b)
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{
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JsonbIterator *ita,
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*itb;
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int res = 0;
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ita = JsonbIteratorInit(a);
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itb = JsonbIteratorInit(b);
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do
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{
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JsonbValue va,
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vb;
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int ra,
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rb;
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ra = JsonbIteratorNext(&ita, &va, false);
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rb = JsonbIteratorNext(&itb, &vb, false);
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if (ra == rb)
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{
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if (ra == WJB_DONE)
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{
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/* Decisively equal */
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break;
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}
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if (ra == WJB_END_ARRAY || ra == WJB_END_OBJECT)
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{
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/*
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* There is no array or object to compare at this stage of
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* processing. jbvArray/jbvObject values are compared
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* initially, at the WJB_BEGIN_ARRAY and WJB_BEGIN_OBJECT
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* tokens.
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*/
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continue;
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}
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if (va.type == vb.type)
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{
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switch (va.type)
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{
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case jbvString:
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case jbvNull:
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case jbvNumeric:
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case jbvBool:
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res = compareJsonbScalarValue(&va, &vb);
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break;
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case jbvArray:
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/*
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* This could be a "raw scalar" pseudo array. That's
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* a special case here though, since we still want the
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* general type-based comparisons to apply, and as far
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* as we're concerned a pseudo array is just a scalar.
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*/
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if (va.val.array.rawScalar != vb.val.array.rawScalar)
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res = (va.val.array.rawScalar) ? -1 : 1;
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if (va.val.array.nElems != vb.val.array.nElems)
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res = (va.val.array.nElems > vb.val.array.nElems) ? 1 : -1;
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break;
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case jbvObject:
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if (va.val.object.nPairs != vb.val.object.nPairs)
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res = (va.val.object.nPairs > vb.val.object.nPairs) ? 1 : -1;
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break;
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case jbvBinary:
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elog(ERROR, "unexpected jbvBinary value");
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}
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}
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else
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{
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/* Type-defined order */
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res = (va.type > vb.type) ? 1 : -1;
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}
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}
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else
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{
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/*
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* It's safe to assume that the types differed, and that the va
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* and vb values passed were set.
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*
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* If the two values were of the same container type, then there'd
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* have been a chance to observe the variation in the number of
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* elements/pairs (when processing WJB_BEGIN_OBJECT, say). They're
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* either two heterogeneously-typed containers, or a container and
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* some scalar type.
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*
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* We don't have to consider the WJB_END_ARRAY and WJB_END_OBJECT
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* cases here, because we would have seen the corresponding
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* WJB_BEGIN_ARRAY and WJB_BEGIN_OBJECT tokens first, and
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* concluded that they don't match.
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*/
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Assert(ra != WJB_END_ARRAY && ra != WJB_END_OBJECT);
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Assert(rb != WJB_END_ARRAY && rb != WJB_END_OBJECT);
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Assert(va.type != vb.type);
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Assert(va.type != jbvBinary);
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Assert(vb.type != jbvBinary);
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/* Type-defined order */
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res = (va.type > vb.type) ? 1 : -1;
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}
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}
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while (res == 0);
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while (ita != NULL)
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{
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JsonbIterator *i = ita->parent;
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pfree(ita);
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ita = i;
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}
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while (itb != NULL)
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{
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JsonbIterator *i = itb->parent;
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pfree(itb);
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itb = i;
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}
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return res;
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}
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/*
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* Find value in object (i.e. the "value" part of some key/value pair in an
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* object), or find a matching element if we're looking through an array. Do
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* so on the basis of equality of the object keys only, or alternatively
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* element values only, with a caller-supplied value "key". The "flags"
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* argument allows the caller to specify which container types are of interest.
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*
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* This exported utility function exists to facilitate various cases concerned
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* with "containment". If asked to look through an object, the caller had
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* better pass a Jsonb String, because their keys can only be strings.
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* Otherwise, for an array, any type of JsonbValue will do.
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*
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* In order to proceed with the search, it is necessary for callers to have
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* both specified an interest in exactly one particular container type with an
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* appropriate flag, as well as having the pointed-to Jsonb container be of
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* one of those same container types at the top level. (Actually, we just do
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* whichever makes sense to save callers the trouble of figuring it out - at
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* most one can make sense, because the container either points to an array
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* (possibly a "raw scalar" pseudo array) or an object.)
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*
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* Note that we can return a jbvBinary JsonbValue if this is called on an
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* object, but we never do so on an array. If the caller asks to look through
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* a container type that is not of the type pointed to by the container,
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* immediately fall through and return NULL. If we cannot find the value,
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* return NULL. Otherwise, return palloc()'d copy of value.
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*/
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JsonbValue *
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findJsonbValueFromContainer(JsonbContainer *container, uint32 flags,
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JsonbValue *key)
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{
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JEntry *children = container->children;
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int count = (container->header & JB_CMASK);
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JsonbValue *result;
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Assert((flags & ~(JB_FARRAY | JB_FOBJECT)) == 0);
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/* Quick out without a palloc cycle if object/array is empty */
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if (count <= 0)
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return NULL;
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result = palloc(sizeof(JsonbValue));
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if (flags & JB_FARRAY & container->header)
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{
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char *base_addr = (char *) (children + count);
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uint32 offset = 0;
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int i;
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for (i = 0; i < count; i++)
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{
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fillJsonbValue(container, i, base_addr, offset, result);
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if (key->type == result->type)
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{
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if (equalsJsonbScalarValue(key, result))
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return result;
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}
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JBE_ADVANCE_OFFSET(offset, children[i]);
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}
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}
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else if (flags & JB_FOBJECT & container->header)
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{
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/* Since this is an object, account for *Pairs* of Jentrys */
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char *base_addr = (char *) (children + count * 2);
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uint32 stopLow = 0,
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stopHigh = count;
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/* Object key passed by caller must be a string */
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Assert(key->type == jbvString);
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/* Binary search on object/pair keys *only* */
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while (stopLow < stopHigh)
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{
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uint32 stopMiddle;
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int difference;
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JsonbValue candidate;
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stopMiddle = stopLow + (stopHigh - stopLow) / 2;
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candidate.type = jbvString;
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candidate.val.string.val =
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base_addr + getJsonbOffset(container, stopMiddle);
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candidate.val.string.len = getJsonbLength(container, stopMiddle);
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difference = lengthCompareJsonbStringValue(&candidate, key);
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if (difference == 0)
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{
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/* Found our key, return corresponding value */
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int index = stopMiddle + count;
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fillJsonbValue(container, index, base_addr,
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getJsonbOffset(container, index),
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result);
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return result;
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}
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else
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{
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if (difference < 0)
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stopLow = stopMiddle + 1;
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else
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stopHigh = stopMiddle;
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}
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}
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}
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/* Not found */
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pfree(result);
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return NULL;
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}
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/*
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* Get i-th value of a Jsonb array.
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*
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* Returns palloc()'d copy of the value, or NULL if it does not exist.
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*/
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JsonbValue *
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getIthJsonbValueFromContainer(JsonbContainer *container, uint32 i)
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{
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JsonbValue *result;
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char *base_addr;
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uint32 nelements;
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if ((container->header & JB_FARRAY) == 0)
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elog(ERROR, "not a jsonb array");
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nelements = container->header & JB_CMASK;
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base_addr = (char *) &container->children[nelements];
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if (i >= nelements)
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return NULL;
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result = palloc(sizeof(JsonbValue));
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fillJsonbValue(container, i, base_addr,
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getJsonbOffset(container, i),
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result);
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return result;
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}
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|
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/*
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* A helper function to fill in a JsonbValue to represent an element of an
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* array, or a key or value of an object.
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*
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* The node's JEntry is at container->children[index], and its variable-length
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* data is at base_addr + offset. We make the caller determine the offset
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* since in many cases the caller can amortize that work across multiple
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* children. When it can't, it can just call getJsonbOffset().
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*
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* A nested array or object will be returned as jbvBinary, ie. it won't be
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* expanded.
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*/
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static void
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fillJsonbValue(JsonbContainer *container, int index,
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char *base_addr, uint32 offset,
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JsonbValue *result)
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{
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JEntry entry = container->children[index];
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|
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if (JBE_ISNULL(entry))
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{
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result->type = jbvNull;
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}
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else if (JBE_ISSTRING(entry))
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{
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result->type = jbvString;
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result->val.string.val = base_addr + offset;
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result->val.string.len = getJsonbLength(container, index);
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Assert(result->val.string.len >= 0);
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}
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else if (JBE_ISNUMERIC(entry))
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{
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result->type = jbvNumeric;
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result->val.numeric = (Numeric) (base_addr + INTALIGN(offset));
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}
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else if (JBE_ISBOOL_TRUE(entry))
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{
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result->type = jbvBool;
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result->val.boolean = true;
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}
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else if (JBE_ISBOOL_FALSE(entry))
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{
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result->type = jbvBool;
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result->val.boolean = false;
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}
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else
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{
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Assert(JBE_ISCONTAINER(entry));
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result->type = jbvBinary;
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/* Remove alignment padding from data pointer and length */
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result->val.binary.data = (JsonbContainer *) (base_addr + INTALIGN(offset));
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result->val.binary.len = getJsonbLength(container, index) -
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(INTALIGN(offset) - offset);
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}
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}
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/*
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* Push JsonbValue into JsonbParseState.
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*
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* Used when parsing JSON tokens to form Jsonb, or when converting an in-memory
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* JsonbValue to a Jsonb.
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*
|
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* Initial state of *JsonbParseState is NULL, since it'll be allocated here
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* originally (caller will get JsonbParseState back by reference).
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*
|
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* Only sequential tokens pertaining to non-container types should pass a
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* JsonbValue. There is one exception -- WJB_BEGIN_ARRAY callers may pass a
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* "raw scalar" pseudo array to append it - the actual scalar should be passed
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* next and it will be added as the only member of the array.
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*
|
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* Values of type jvbBinary, which are rolled up arrays and objects,
|
|
* are unpacked before being added to the result.
|
|
*/
|
|
JsonbValue *
|
|
pushJsonbValue(JsonbParseState **pstate, JsonbIteratorToken seq,
|
|
JsonbValue *jbval)
|
|
{
|
|
JsonbIterator *it;
|
|
JsonbValue *res = NULL;
|
|
JsonbValue v;
|
|
JsonbIteratorToken tok;
|
|
|
|
if (!jbval || (seq != WJB_ELEM && seq != WJB_VALUE) ||
|
|
jbval->type != jbvBinary)
|
|
{
|
|
/* drop through */
|
|
return pushJsonbValueScalar(pstate, seq, jbval);
|
|
}
|
|
|
|
/* unpack the binary and add each piece to the pstate */
|
|
it = JsonbIteratorInit(jbval->val.binary.data);
|
|
while ((tok = JsonbIteratorNext(&it, &v, false)) != WJB_DONE)
|
|
res = pushJsonbValueScalar(pstate, tok,
|
|
tok < WJB_BEGIN_ARRAY ? &v : NULL);
|
|
|
|
return res;
|
|
}
|
|
|
|
/*
|
|
* Do the actual pushing, with only scalar or pseudo-scalar-array values
|
|
* accepted.
|
|
*/
|
|
static JsonbValue *
|
|
pushJsonbValueScalar(JsonbParseState **pstate, JsonbIteratorToken seq,
|
|
JsonbValue *scalarVal)
|
|
{
|
|
JsonbValue *result = NULL;
|
|
|
|
switch (seq)
|
|
{
|
|
case WJB_BEGIN_ARRAY:
|
|
Assert(!scalarVal || scalarVal->val.array.rawScalar);
|
|
*pstate = pushState(pstate);
|
|
result = &(*pstate)->contVal;
|
|
(*pstate)->contVal.type = jbvArray;
|
|
(*pstate)->contVal.val.array.nElems = 0;
|
|
(*pstate)->contVal.val.array.rawScalar = (scalarVal &&
|
|
scalarVal->val.array.rawScalar);
|
|
if (scalarVal && scalarVal->val.array.nElems > 0)
|
|
{
|
|
/* Assume that this array is still really a scalar */
|
|
Assert(scalarVal->type == jbvArray);
|
|
(*pstate)->size = scalarVal->val.array.nElems;
|
|
}
|
|
else
|
|
{
|
|
(*pstate)->size = 4;
|
|
}
|
|
(*pstate)->contVal.val.array.elems = palloc(sizeof(JsonbValue) *
|
|
(*pstate)->size);
|
|
break;
|
|
case WJB_BEGIN_OBJECT:
|
|
Assert(!scalarVal);
|
|
*pstate = pushState(pstate);
|
|
result = &(*pstate)->contVal;
|
|
(*pstate)->contVal.type = jbvObject;
|
|
(*pstate)->contVal.val.object.nPairs = 0;
|
|
(*pstate)->size = 4;
|
|
(*pstate)->contVal.val.object.pairs = palloc(sizeof(JsonbPair) *
|
|
(*pstate)->size);
|
|
break;
|
|
case WJB_KEY:
|
|
Assert(scalarVal->type == jbvString);
|
|
appendKey(*pstate, scalarVal);
|
|
break;
|
|
case WJB_VALUE:
|
|
Assert(IsAJsonbScalar(scalarVal));
|
|
appendValue(*pstate, scalarVal);
|
|
break;
|
|
case WJB_ELEM:
|
|
Assert(IsAJsonbScalar(scalarVal));
|
|
appendElement(*pstate, scalarVal);
|
|
break;
|
|
case WJB_END_OBJECT:
|
|
uniqueifyJsonbObject(&(*pstate)->contVal);
|
|
/* fall through! */
|
|
case WJB_END_ARRAY:
|
|
/* Steps here common to WJB_END_OBJECT case */
|
|
Assert(!scalarVal);
|
|
result = &(*pstate)->contVal;
|
|
|
|
/*
|
|
* Pop stack and push current array/object as value in parent
|
|
* array/object
|
|
*/
|
|
*pstate = (*pstate)->next;
|
|
if (*pstate)
|
|
{
|
|
switch ((*pstate)->contVal.type)
|
|
{
|
|
case jbvArray:
|
|
appendElement(*pstate, result);
|
|
break;
|
|
case jbvObject:
|
|
appendValue(*pstate, result);
|
|
break;
|
|
default:
|
|
elog(ERROR, "invalid jsonb container type");
|
|
}
|
|
}
|
|
break;
|
|
default:
|
|
elog(ERROR, "unrecognized jsonb sequential processing token");
|
|
}
|
|
|
|
return result;
|
|
}
|
|
|
|
/*
|
|
* pushJsonbValue() worker: Iteration-like forming of Jsonb
|
|
*/
|
|
static JsonbParseState *
|
|
pushState(JsonbParseState **pstate)
|
|
{
|
|
JsonbParseState *ns = palloc(sizeof(JsonbParseState));
|
|
|
|
ns->next = *pstate;
|
|
return ns;
|
|
}
|
|
|
|
/*
|
|
* pushJsonbValue() worker: Append a pair key to state when generating a Jsonb
|
|
*/
|
|
static void
|
|
appendKey(JsonbParseState *pstate, JsonbValue *string)
|
|
{
|
|
JsonbValue *object = &pstate->contVal;
|
|
|
|
Assert(object->type == jbvObject);
|
|
Assert(string->type == jbvString);
|
|
|
|
if (object->val.object.nPairs >= JSONB_MAX_PAIRS)
|
|
ereport(ERROR,
|
|
(errcode(ERRCODE_PROGRAM_LIMIT_EXCEEDED),
|
|
errmsg("number of jsonb object pairs exceeds the maximum allowed (%zu)",
|
|
JSONB_MAX_PAIRS)));
|
|
|
|
if (object->val.object.nPairs >= pstate->size)
|
|
{
|
|
pstate->size *= 2;
|
|
object->val.object.pairs = repalloc(object->val.object.pairs,
|
|
sizeof(JsonbPair) * pstate->size);
|
|
}
|
|
|
|
object->val.object.pairs[object->val.object.nPairs].key = *string;
|
|
object->val.object.pairs[object->val.object.nPairs].order = object->val.object.nPairs;
|
|
}
|
|
|
|
/*
|
|
* pushJsonbValue() worker: Append a pair value to state when generating a
|
|
* Jsonb
|
|
*/
|
|
static void
|
|
appendValue(JsonbParseState *pstate, JsonbValue *scalarVal)
|
|
{
|
|
JsonbValue *object = &pstate->contVal;
|
|
|
|
Assert(object->type == jbvObject);
|
|
|
|
object->val.object.pairs[object->val.object.nPairs++].value = *scalarVal;
|
|
}
|
|
|
|
/*
|
|
* pushJsonbValue() worker: Append an element to state when generating a Jsonb
|
|
*/
|
|
static void
|
|
appendElement(JsonbParseState *pstate, JsonbValue *scalarVal)
|
|
{
|
|
JsonbValue *array = &pstate->contVal;
|
|
|
|
Assert(array->type == jbvArray);
|
|
|
|
if (array->val.array.nElems >= JSONB_MAX_ELEMS)
|
|
ereport(ERROR,
|
|
(errcode(ERRCODE_PROGRAM_LIMIT_EXCEEDED),
|
|
errmsg("number of jsonb array elements exceeds the maximum allowed (%zu)",
|
|
JSONB_MAX_ELEMS)));
|
|
|
|
if (array->val.array.nElems >= pstate->size)
|
|
{
|
|
pstate->size *= 2;
|
|
array->val.array.elems = repalloc(array->val.array.elems,
|
|
sizeof(JsonbValue) * pstate->size);
|
|
}
|
|
|
|
array->val.array.elems[array->val.array.nElems++] = *scalarVal;
|
|
}
|
|
|
|
/*
|
|
* Given a JsonbContainer, expand to JsonbIterator to iterate over items
|
|
* fully expanded to in-memory representation for manipulation.
|
|
*
|
|
* See JsonbIteratorNext() for notes on memory management.
|
|
*/
|
|
JsonbIterator *
|
|
JsonbIteratorInit(JsonbContainer *container)
|
|
{
|
|
return iteratorFromContainer(container, NULL);
|
|
}
|
|
|
|
/*
|
|
* Get next JsonbValue while iterating
|
|
*
|
|
* Caller should initially pass their own, original iterator. They may get
|
|
* back a child iterator palloc()'d here instead. The function can be relied
|
|
* on to free those child iterators, lest the memory allocated for highly
|
|
* nested objects become unreasonable, but only if callers don't end iteration
|
|
* early (by breaking upon having found something in a search, for example).
|
|
*
|
|
* Callers in such a scenario, that are particularly sensitive to leaking
|
|
* memory in a long-lived context may walk the ancestral tree from the final
|
|
* iterator we left them with to its oldest ancestor, pfree()ing as they go.
|
|
* They do not have to free any other memory previously allocated for iterators
|
|
* but not accessible as direct ancestors of the iterator they're last passed
|
|
* back.
|
|
*
|
|
* Returns "Jsonb sequential processing" token value. Iterator "state"
|
|
* reflects the current stage of the process in a less granular fashion, and is
|
|
* mostly used here to track things internally with respect to particular
|
|
* iterators.
|
|
*
|
|
* Clients of this function should not have to handle any jbvBinary values
|
|
* (since recursive calls will deal with this), provided skipNested is false.
|
|
* It is our job to expand the jbvBinary representation without bothering them
|
|
* with it. However, clients should not take it upon themselves to touch array
|
|
* or Object element/pair buffers, since their element/pair pointers are
|
|
* garbage. Also, *val will not be set when returning WJB_END_ARRAY or
|
|
* WJB_END_OBJECT, on the assumption that it's only useful to access values
|
|
* when recursing in.
|
|
*/
|
|
JsonbIteratorToken
|
|
JsonbIteratorNext(JsonbIterator **it, JsonbValue *val, bool skipNested)
|
|
{
|
|
if (*it == NULL)
|
|
return WJB_DONE;
|
|
|
|
/*
|
|
* When stepping into a nested container, we jump back here to start
|
|
* processing the child. We will not recurse further in one call, because
|
|
* processing the child will always begin in JBI_ARRAY_START or
|
|
* JBI_OBJECT_START state.
|
|
*/
|
|
recurse:
|
|
switch ((*it)->state)
|
|
{
|
|
case JBI_ARRAY_START:
|
|
/* Set v to array on first array call */
|
|
val->type = jbvArray;
|
|
val->val.array.nElems = (*it)->nElems;
|
|
|
|
/*
|
|
* v->val.array.elems is not actually set, because we aren't doing
|
|
* a full conversion
|
|
*/
|
|
val->val.array.rawScalar = (*it)->isScalar;
|
|
(*it)->curIndex = 0;
|
|
(*it)->curDataOffset = 0;
|
|
(*it)->curValueOffset = 0; /* not actually used */
|
|
/* Set state for next call */
|
|
(*it)->state = JBI_ARRAY_ELEM;
|
|
return WJB_BEGIN_ARRAY;
|
|
|
|
case JBI_ARRAY_ELEM:
|
|
if ((*it)->curIndex >= (*it)->nElems)
|
|
{
|
|
/*
|
|
* All elements within array already processed. Report this
|
|
* to caller, and give it back original parent iterator (which
|
|
* independently tracks iteration progress at its level of
|
|
* nesting).
|
|
*/
|
|
*it = freeAndGetParent(*it);
|
|
return WJB_END_ARRAY;
|
|
}
|
|
|
|
fillJsonbValue((*it)->container, (*it)->curIndex,
|
|
(*it)->dataProper, (*it)->curDataOffset,
|
|
val);
|
|
|
|
JBE_ADVANCE_OFFSET((*it)->curDataOffset,
|
|
(*it)->children[(*it)->curIndex]);
|
|
(*it)->curIndex++;
|
|
|
|
if (!IsAJsonbScalar(val) && !skipNested)
|
|
{
|
|
/* Recurse into container. */
|
|
*it = iteratorFromContainer(val->val.binary.data, *it);
|
|
goto recurse;
|
|
}
|
|
else
|
|
{
|
|
/*
|
|
* Scalar item in array, or a container and caller didn't want
|
|
* us to recurse into it.
|
|
*/
|
|
return WJB_ELEM;
|
|
}
|
|
|
|
case JBI_OBJECT_START:
|
|
/* Set v to object on first object call */
|
|
val->type = jbvObject;
|
|
val->val.object.nPairs = (*it)->nElems;
|
|
|
|
/*
|
|
* v->val.object.pairs is not actually set, because we aren't
|
|
* doing a full conversion
|
|
*/
|
|
(*it)->curIndex = 0;
|
|
(*it)->curDataOffset = 0;
|
|
(*it)->curValueOffset = getJsonbOffset((*it)->container,
|
|
(*it)->nElems);
|
|
/* Set state for next call */
|
|
(*it)->state = JBI_OBJECT_KEY;
|
|
return WJB_BEGIN_OBJECT;
|
|
|
|
case JBI_OBJECT_KEY:
|
|
if ((*it)->curIndex >= (*it)->nElems)
|
|
{
|
|
/*
|
|
* All pairs within object already processed. Report this to
|
|
* caller, and give it back original containing iterator
|
|
* (which independently tracks iteration progress at its level
|
|
* of nesting).
|
|
*/
|
|
*it = freeAndGetParent(*it);
|
|
return WJB_END_OBJECT;
|
|
}
|
|
else
|
|
{
|
|
/* Return key of a key/value pair. */
|
|
fillJsonbValue((*it)->container, (*it)->curIndex,
|
|
(*it)->dataProper, (*it)->curDataOffset,
|
|
val);
|
|
if (val->type != jbvString)
|
|
elog(ERROR, "unexpected jsonb type as object key");
|
|
|
|
/* Set state for next call */
|
|
(*it)->state = JBI_OBJECT_VALUE;
|
|
return WJB_KEY;
|
|
}
|
|
|
|
case JBI_OBJECT_VALUE:
|
|
/* Set state for next call */
|
|
(*it)->state = JBI_OBJECT_KEY;
|
|
|
|
fillJsonbValue((*it)->container, (*it)->curIndex + (*it)->nElems,
|
|
(*it)->dataProper, (*it)->curValueOffset,
|
|
val);
|
|
|
|
JBE_ADVANCE_OFFSET((*it)->curDataOffset,
|
|
(*it)->children[(*it)->curIndex]);
|
|
JBE_ADVANCE_OFFSET((*it)->curValueOffset,
|
|
(*it)->children[(*it)->curIndex + (*it)->nElems]);
|
|
(*it)->curIndex++;
|
|
|
|
/*
|
|
* Value may be a container, in which case we recurse with new,
|
|
* child iterator (unless the caller asked not to, by passing
|
|
* skipNested).
|
|
*/
|
|
if (!IsAJsonbScalar(val) && !skipNested)
|
|
{
|
|
*it = iteratorFromContainer(val->val.binary.data, *it);
|
|
goto recurse;
|
|
}
|
|
else
|
|
return WJB_VALUE;
|
|
}
|
|
|
|
elog(ERROR, "invalid iterator state");
|
|
return -1;
|
|
}
|
|
|
|
/*
|
|
* Initialize an iterator for iterating all elements in a container.
|
|
*/
|
|
static JsonbIterator *
|
|
iteratorFromContainer(JsonbContainer *container, JsonbIterator *parent)
|
|
{
|
|
JsonbIterator *it;
|
|
|
|
it = palloc(sizeof(JsonbIterator));
|
|
it->container = container;
|
|
it->parent = parent;
|
|
it->nElems = container->header & JB_CMASK;
|
|
|
|
/* Array starts just after header */
|
|
it->children = container->children;
|
|
|
|
switch (container->header & (JB_FARRAY | JB_FOBJECT))
|
|
{
|
|
case JB_FARRAY:
|
|
it->dataProper =
|
|
(char *) it->children + it->nElems * sizeof(JEntry);
|
|
it->isScalar = (container->header & JB_FSCALAR) != 0;
|
|
/* This is either a "raw scalar", or an array */
|
|
Assert(!it->isScalar || it->nElems == 1);
|
|
|
|
it->state = JBI_ARRAY_START;
|
|
break;
|
|
|
|
case JB_FOBJECT:
|
|
it->dataProper =
|
|
(char *) it->children + it->nElems * sizeof(JEntry) * 2;
|
|
it->state = JBI_OBJECT_START;
|
|
break;
|
|
|
|
default:
|
|
elog(ERROR, "unknown type of jsonb container");
|
|
}
|
|
|
|
return it;
|
|
}
|
|
|
|
/*
|
|
* JsonbIteratorNext() worker: Return parent, while freeing memory for current
|
|
* iterator
|
|
*/
|
|
static JsonbIterator *
|
|
freeAndGetParent(JsonbIterator *it)
|
|
{
|
|
JsonbIterator *v = it->parent;
|
|
|
|
pfree(it);
|
|
return v;
|
|
}
|
|
|
|
/*
|
|
* Worker for "contains" operator's function
|
|
*
|
|
* Formally speaking, containment is top-down, unordered subtree isomorphism.
|
|
*
|
|
* Takes iterators that belong to some container type. These iterators
|
|
* "belong" to those values in the sense that they've just been initialized in
|
|
* respect of them by the caller (perhaps in a nested fashion).
|
|
*
|
|
* "val" is lhs Jsonb, and mContained is rhs Jsonb when called from top level.
|
|
* We determine if mContained is contained within val.
|
|
*/
|
|
bool
|
|
JsonbDeepContains(JsonbIterator **val, JsonbIterator **mContained)
|
|
{
|
|
uint32 rval,
|
|
rcont;
|
|
JsonbValue vval,
|
|
vcontained;
|
|
|
|
/*
|
|
* Guard against stack overflow due to overly complex Jsonb.
|
|
*
|
|
* Functions called here independently take this precaution, but that
|
|
* might not be sufficient since this is also a recursive function.
|
|
*/
|
|
check_stack_depth();
|
|
|
|
rval = JsonbIteratorNext(val, &vval, false);
|
|
rcont = JsonbIteratorNext(mContained, &vcontained, false);
|
|
|
|
if (rval != rcont)
|
|
{
|
|
/*
|
|
* The differing return values can immediately be taken as indicating
|
|
* two differing container types at this nesting level, which is
|
|
* sufficient reason to give up entirely (but it should be the case
|
|
* that they're both some container type).
|
|
*/
|
|
Assert(rval == WJB_BEGIN_OBJECT || rval == WJB_BEGIN_ARRAY);
|
|
Assert(rcont == WJB_BEGIN_OBJECT || rcont == WJB_BEGIN_ARRAY);
|
|
return false;
|
|
}
|
|
else if (rcont == WJB_BEGIN_OBJECT)
|
|
{
|
|
Assert(vval.type == jbvObject);
|
|
Assert(vcontained.type == jbvObject);
|
|
|
|
/*
|
|
* If the lhs has fewer pairs than the rhs, it can't possibly contain
|
|
* the rhs. (This conclusion is safe only because we de-duplicate
|
|
* keys in all Jsonb objects; thus there can be no corresponding
|
|
* optimization in the array case.) The case probably won't arise
|
|
* often, but since it's such a cheap check we may as well make it.
|
|
*/
|
|
if (vval.val.object.nPairs < vcontained.val.object.nPairs)
|
|
return false;
|
|
|
|
/* Work through rhs "is it contained within?" object */
|
|
for (;;)
|
|
{
|
|
JsonbValue *lhsVal; /* lhsVal is from pair in lhs object */
|
|
|
|
rcont = JsonbIteratorNext(mContained, &vcontained, false);
|
|
|
|
/*
|
|
* When we get through caller's rhs "is it contained within?"
|
|
* object without failing to find one of its values, it's
|
|
* contained.
|
|
*/
|
|
if (rcont == WJB_END_OBJECT)
|
|
return true;
|
|
|
|
Assert(rcont == WJB_KEY);
|
|
|
|
/* First, find value by key... */
|
|
lhsVal = findJsonbValueFromContainer((*val)->container,
|
|
JB_FOBJECT,
|
|
&vcontained);
|
|
|
|
if (!lhsVal)
|
|
return false;
|
|
|
|
/*
|
|
* ...at this stage it is apparent that there is at least a key
|
|
* match for this rhs pair.
|
|
*/
|
|
rcont = JsonbIteratorNext(mContained, &vcontained, true);
|
|
|
|
Assert(rcont == WJB_VALUE);
|
|
|
|
/*
|
|
* Compare rhs pair's value with lhs pair's value just found using
|
|
* key
|
|
*/
|
|
if (lhsVal->type != vcontained.type)
|
|
{
|
|
return false;
|
|
}
|
|
else if (IsAJsonbScalar(lhsVal))
|
|
{
|
|
if (!equalsJsonbScalarValue(lhsVal, &vcontained))
|
|
return false;
|
|
}
|
|
else
|
|
{
|
|
/* Nested container value (object or array) */
|
|
JsonbIterator *nestval,
|
|
*nestContained;
|
|
|
|
Assert(lhsVal->type == jbvBinary);
|
|
Assert(vcontained.type == jbvBinary);
|
|
|
|
nestval = JsonbIteratorInit(lhsVal->val.binary.data);
|
|
nestContained = JsonbIteratorInit(vcontained.val.binary.data);
|
|
|
|
/*
|
|
* Match "value" side of rhs datum object's pair recursively.
|
|
* It's a nested structure.
|
|
*
|
|
* Note that nesting still has to "match up" at the right
|
|
* nesting sub-levels. However, there need only be zero or
|
|
* more matching pairs (or elements) at each nesting level
|
|
* (provided the *rhs* pairs/elements *all* match on each
|
|
* level), which enables searching nested structures for a
|
|
* single String or other primitive type sub-datum quite
|
|
* effectively (provided the user constructed the rhs nested
|
|
* structure such that we "know where to look").
|
|
*
|
|
* In other words, the mapping of container nodes in the rhs
|
|
* "vcontained" Jsonb to internal nodes on the lhs is
|
|
* injective, and parent-child edges on the rhs must be mapped
|
|
* to parent-child edges on the lhs to satisfy the condition
|
|
* of containment (plus of course the mapped nodes must be
|
|
* equal).
|
|
*/
|
|
if (!JsonbDeepContains(&nestval, &nestContained))
|
|
return false;
|
|
}
|
|
}
|
|
}
|
|
else if (rcont == WJB_BEGIN_ARRAY)
|
|
{
|
|
JsonbValue *lhsConts = NULL;
|
|
uint32 nLhsElems = vval.val.array.nElems;
|
|
|
|
Assert(vval.type == jbvArray);
|
|
Assert(vcontained.type == jbvArray);
|
|
|
|
/*
|
|
* Handle distinction between "raw scalar" pseudo arrays, and real
|
|
* arrays.
|
|
*
|
|
* A raw scalar may contain another raw scalar, and an array may
|
|
* contain a raw scalar, but a raw scalar may not contain an array. We
|
|
* don't do something like this for the object case, since objects can
|
|
* only contain pairs, never raw scalars (a pair is represented by an
|
|
* rhs object argument with a single contained pair).
|
|
*/
|
|
if (vval.val.array.rawScalar && !vcontained.val.array.rawScalar)
|
|
return false;
|
|
|
|
/* Work through rhs "is it contained within?" array */
|
|
for (;;)
|
|
{
|
|
rcont = JsonbIteratorNext(mContained, &vcontained, true);
|
|
|
|
/*
|
|
* When we get through caller's rhs "is it contained within?"
|
|
* array without failing to find one of its values, it's
|
|
* contained.
|
|
*/
|
|
if (rcont == WJB_END_ARRAY)
|
|
return true;
|
|
|
|
Assert(rcont == WJB_ELEM);
|
|
|
|
if (IsAJsonbScalar(&vcontained))
|
|
{
|
|
if (!findJsonbValueFromContainer((*val)->container,
|
|
JB_FARRAY,
|
|
&vcontained))
|
|
return false;
|
|
}
|
|
else
|
|
{
|
|
uint32 i;
|
|
|
|
/*
|
|
* If this is first container found in rhs array (at this
|
|
* depth), initialize temp lhs array of containers
|
|
*/
|
|
if (lhsConts == NULL)
|
|
{
|
|
uint32 j = 0;
|
|
|
|
/* Make room for all possible values */
|
|
lhsConts = palloc(sizeof(JsonbValue) * nLhsElems);
|
|
|
|
for (i = 0; i < nLhsElems; i++)
|
|
{
|
|
/* Store all lhs elements in temp array */
|
|
rcont = JsonbIteratorNext(val, &vval, true);
|
|
Assert(rcont == WJB_ELEM);
|
|
|
|
if (vval.type == jbvBinary)
|
|
lhsConts[j++] = vval;
|
|
}
|
|
|
|
/* No container elements in temp array, so give up now */
|
|
if (j == 0)
|
|
return false;
|
|
|
|
/* We may have only partially filled array */
|
|
nLhsElems = j;
|
|
}
|
|
|
|
/* XXX: Nested array containment is O(N^2) */
|
|
for (i = 0; i < nLhsElems; i++)
|
|
{
|
|
/* Nested container value (object or array) */
|
|
JsonbIterator *nestval,
|
|
*nestContained;
|
|
bool contains;
|
|
|
|
nestval = JsonbIteratorInit(lhsConts[i].val.binary.data);
|
|
nestContained = JsonbIteratorInit(vcontained.val.binary.data);
|
|
|
|
contains = JsonbDeepContains(&nestval, &nestContained);
|
|
|
|
if (nestval)
|
|
pfree(nestval);
|
|
if (nestContained)
|
|
pfree(nestContained);
|
|
if (contains)
|
|
break;
|
|
}
|
|
|
|
/*
|
|
* Report rhs container value is not contained if couldn't
|
|
* match rhs container to *some* lhs cont
|
|
*/
|
|
if (i == nLhsElems)
|
|
return false;
|
|
}
|
|
}
|
|
}
|
|
else
|
|
{
|
|
elog(ERROR, "invalid jsonb container type");
|
|
}
|
|
|
|
elog(ERROR, "unexpectedly fell off end of jsonb container");
|
|
return false;
|
|
}
|
|
|
|
/*
|
|
* Hash a JsonbValue scalar value, mixing the hash value into an existing
|
|
* hash provided by the caller.
|
|
*
|
|
* Some callers may wish to independently XOR in JB_FOBJECT and JB_FARRAY
|
|
* flags.
|
|
*/
|
|
void
|
|
JsonbHashScalarValue(const JsonbValue *scalarVal, uint32 *hash)
|
|
{
|
|
uint32 tmp;
|
|
|
|
/* Compute hash value for scalarVal */
|
|
switch (scalarVal->type)
|
|
{
|
|
case jbvNull:
|
|
tmp = 0x01;
|
|
break;
|
|
case jbvString:
|
|
tmp = DatumGetUInt32(hash_any((const unsigned char *) scalarVal->val.string.val,
|
|
scalarVal->val.string.len));
|
|
break;
|
|
case jbvNumeric:
|
|
/* Must hash equal numerics to equal hash codes */
|
|
tmp = DatumGetUInt32(DirectFunctionCall1(hash_numeric,
|
|
NumericGetDatum(scalarVal->val.numeric)));
|
|
break;
|
|
case jbvBool:
|
|
tmp = scalarVal->val.boolean ? 0x02 : 0x04;
|
|
|
|
break;
|
|
default:
|
|
elog(ERROR, "invalid jsonb scalar type");
|
|
tmp = 0; /* keep compiler quiet */
|
|
break;
|
|
}
|
|
|
|
/*
|
|
* Combine hash values of successive keys, values and elements by rotating
|
|
* the previous value left 1 bit, then XOR'ing in the new
|
|
* key/value/element's hash value.
|
|
*/
|
|
*hash = (*hash << 1) | (*hash >> 31);
|
|
*hash ^= tmp;
|
|
}
|
|
|
|
/*
|
|
* Are two scalar JsonbValues of the same type a and b equal?
|
|
*/
|
|
static bool
|
|
equalsJsonbScalarValue(JsonbValue *aScalar, JsonbValue *bScalar)
|
|
{
|
|
if (aScalar->type == bScalar->type)
|
|
{
|
|
switch (aScalar->type)
|
|
{
|
|
case jbvNull:
|
|
return true;
|
|
case jbvString:
|
|
return lengthCompareJsonbStringValue(aScalar, bScalar) == 0;
|
|
case jbvNumeric:
|
|
return DatumGetBool(DirectFunctionCall2(numeric_eq,
|
|
PointerGetDatum(aScalar->val.numeric),
|
|
PointerGetDatum(bScalar->val.numeric)));
|
|
case jbvBool:
|
|
return aScalar->val.boolean == bScalar->val.boolean;
|
|
|
|
default:
|
|
elog(ERROR, "invalid jsonb scalar type");
|
|
}
|
|
}
|
|
elog(ERROR, "jsonb scalar type mismatch");
|
|
return -1;
|
|
}
|
|
|
|
/*
|
|
* Compare two scalar JsonbValues, returning -1, 0, or 1.
|
|
*
|
|
* Strings are compared using the default collation. Used by B-tree
|
|
* operators, where a lexical sort order is generally expected.
|
|
*/
|
|
static int
|
|
compareJsonbScalarValue(JsonbValue *aScalar, JsonbValue *bScalar)
|
|
{
|
|
if (aScalar->type == bScalar->type)
|
|
{
|
|
switch (aScalar->type)
|
|
{
|
|
case jbvNull:
|
|
return 0;
|
|
case jbvString:
|
|
return varstr_cmp(aScalar->val.string.val,
|
|
aScalar->val.string.len,
|
|
bScalar->val.string.val,
|
|
bScalar->val.string.len,
|
|
DEFAULT_COLLATION_OID);
|
|
case jbvNumeric:
|
|
return DatumGetInt32(DirectFunctionCall2(numeric_cmp,
|
|
PointerGetDatum(aScalar->val.numeric),
|
|
PointerGetDatum(bScalar->val.numeric)));
|
|
case jbvBool:
|
|
if (aScalar->val.boolean == bScalar->val.boolean)
|
|
return 0;
|
|
else if (aScalar->val.boolean >bScalar->val.boolean)
|
|
return 1;
|
|
else
|
|
return -1;
|
|
default:
|
|
elog(ERROR, "invalid jsonb scalar type");
|
|
}
|
|
}
|
|
elog(ERROR, "jsonb scalar type mismatch");
|
|
return -1;
|
|
}
|
|
|
|
|
|
/*
|
|
* Functions for manipulating the resizeable buffer used by convertJsonb and
|
|
* its subroutines.
|
|
*/
|
|
|
|
/*
|
|
* Reserve 'len' bytes, at the end of the buffer, enlarging it if necessary.
|
|
* Returns the offset to the reserved area. The caller is expected to fill
|
|
* the reserved area later with copyToBuffer().
|
|
*/
|
|
static int
|
|
reserveFromBuffer(StringInfo buffer, int len)
|
|
{
|
|
int offset;
|
|
|
|
/* Make more room if needed */
|
|
enlargeStringInfo(buffer, len);
|
|
|
|
/* remember current offset */
|
|
offset = buffer->len;
|
|
|
|
/* reserve the space */
|
|
buffer->len += len;
|
|
|
|
/*
|
|
* Keep a trailing null in place, even though it's not useful for us; it
|
|
* seems best to preserve the invariants of StringInfos.
|
|
*/
|
|
buffer->data[buffer->len] = '\0';
|
|
|
|
return offset;
|
|
}
|
|
|
|
/*
|
|
* Copy 'len' bytes to a previously reserved area in buffer.
|
|
*/
|
|
static void
|
|
copyToBuffer(StringInfo buffer, int offset, const char *data, int len)
|
|
{
|
|
memcpy(buffer->data + offset, data, len);
|
|
}
|
|
|
|
/*
|
|
* A shorthand for reserveFromBuffer + copyToBuffer.
|
|
*/
|
|
static void
|
|
appendToBuffer(StringInfo buffer, const char *data, int len)
|
|
{
|
|
int offset;
|
|
|
|
offset = reserveFromBuffer(buffer, len);
|
|
copyToBuffer(buffer, offset, data, len);
|
|
}
|
|
|
|
|
|
/*
|
|
* Append padding, so that the length of the StringInfo is int-aligned.
|
|
* Returns the number of padding bytes appended.
|
|
*/
|
|
static short
|
|
padBufferToInt(StringInfo buffer)
|
|
{
|
|
int padlen,
|
|
p,
|
|
offset;
|
|
|
|
padlen = INTALIGN(buffer->len) - buffer->len;
|
|
|
|
offset = reserveFromBuffer(buffer, padlen);
|
|
|
|
/* padlen must be small, so this is probably faster than a memset */
|
|
for (p = 0; p < padlen; p++)
|
|
buffer->data[offset + p] = '\0';
|
|
|
|
return padlen;
|
|
}
|
|
|
|
/*
|
|
* Given a JsonbValue, convert to Jsonb. The result is palloc'd.
|
|
*/
|
|
static Jsonb *
|
|
convertToJsonb(JsonbValue *val)
|
|
{
|
|
StringInfoData buffer;
|
|
JEntry jentry;
|
|
Jsonb *res;
|
|
|
|
/* Should not already have binary representation */
|
|
Assert(val->type != jbvBinary);
|
|
|
|
/* Allocate an output buffer. It will be enlarged as needed */
|
|
initStringInfo(&buffer);
|
|
|
|
/* Make room for the varlena header */
|
|
reserveFromBuffer(&buffer, VARHDRSZ);
|
|
|
|
convertJsonbValue(&buffer, &jentry, val, 0);
|
|
|
|
/*
|
|
* Note: the JEntry of the root is discarded. Therefore the root
|
|
* JsonbContainer struct must contain enough information to tell what kind
|
|
* of value it is.
|
|
*/
|
|
|
|
res = (Jsonb *) buffer.data;
|
|
|
|
SET_VARSIZE(res, buffer.len);
|
|
|
|
return res;
|
|
}
|
|
|
|
/*
|
|
* Subroutine of convertJsonb: serialize a single JsonbValue into buffer.
|
|
*
|
|
* The JEntry header for this node is returned in *header. It is filled in
|
|
* with the length of this value and appropriate type bits. If we wish to
|
|
* store an end offset rather than a length, it is the caller's responsibility
|
|
* to adjust for that.
|
|
*
|
|
* If the value is an array or an object, this recurses. 'level' is only used
|
|
* for debugging purposes.
|
|
*/
|
|
static void
|
|
convertJsonbValue(StringInfo buffer, JEntry *header, JsonbValue *val, int level)
|
|
{
|
|
check_stack_depth();
|
|
|
|
if (!val)
|
|
return;
|
|
|
|
/*
|
|
* A JsonbValue passed as val should never have a type of jbvBinary, and
|
|
* neither should any of its sub-components. Those values will be produced
|
|
* by convertJsonbArray and convertJsonbObject, the results of which will
|
|
* not be passed back to this function as an argument.
|
|
*/
|
|
|
|
if (IsAJsonbScalar(val))
|
|
convertJsonbScalar(buffer, header, val);
|
|
else if (val->type == jbvArray)
|
|
convertJsonbArray(buffer, header, val, level);
|
|
else if (val->type == jbvObject)
|
|
convertJsonbObject(buffer, header, val, level);
|
|
else
|
|
elog(ERROR, "unknown type of jsonb container to convert");
|
|
}
|
|
|
|
static void
|
|
convertJsonbArray(StringInfo buffer, JEntry *pheader, JsonbValue *val, int level)
|
|
{
|
|
int base_offset;
|
|
int jentry_offset;
|
|
int i;
|
|
int totallen;
|
|
uint32 header;
|
|
int nElems = val->val.array.nElems;
|
|
|
|
/* Remember where in the buffer this array starts. */
|
|
base_offset = buffer->len;
|
|
|
|
/* Align to 4-byte boundary (any padding counts as part of my data) */
|
|
padBufferToInt(buffer);
|
|
|
|
/*
|
|
* Construct the header Jentry and store it in the beginning of the
|
|
* variable-length payload.
|
|
*/
|
|
header = nElems | JB_FARRAY;
|
|
if (val->val.array.rawScalar)
|
|
{
|
|
Assert(nElems == 1);
|
|
Assert(level == 0);
|
|
header |= JB_FSCALAR;
|
|
}
|
|
|
|
appendToBuffer(buffer, (char *) &header, sizeof(uint32));
|
|
|
|
/* Reserve space for the JEntries of the elements. */
|
|
jentry_offset = reserveFromBuffer(buffer, sizeof(JEntry) * nElems);
|
|
|
|
totallen = 0;
|
|
for (i = 0; i < nElems; i++)
|
|
{
|
|
JsonbValue *elem = &val->val.array.elems[i];
|
|
int len;
|
|
JEntry meta;
|
|
|
|
/*
|
|
* Convert element, producing a JEntry and appending its
|
|
* variable-length data to buffer
|
|
*/
|
|
convertJsonbValue(buffer, &meta, elem, level + 1);
|
|
|
|
len = JBE_OFFLENFLD(meta);
|
|
totallen += len;
|
|
|
|
/*
|
|
* Bail out if total variable-length data exceeds what will fit in a
|
|
* JEntry length field. We check this in each iteration, not just
|
|
* once at the end, to forestall possible integer overflow.
|
|
*/
|
|
if (totallen > JENTRY_OFFLENMASK)
|
|
ereport(ERROR,
|
|
(errcode(ERRCODE_PROGRAM_LIMIT_EXCEEDED),
|
|
errmsg("total size of jsonb array elements exceeds the maximum of %u bytes",
|
|
JENTRY_OFFLENMASK)));
|
|
|
|
/*
|
|
* Convert each JB_OFFSET_STRIDE'th length to an offset.
|
|
*/
|
|
if ((i % JB_OFFSET_STRIDE) == 0)
|
|
meta = (meta & JENTRY_TYPEMASK) | totallen | JENTRY_HAS_OFF;
|
|
|
|
copyToBuffer(buffer, jentry_offset, (char *) &meta, sizeof(JEntry));
|
|
jentry_offset += sizeof(JEntry);
|
|
}
|
|
|
|
/* Total data size is everything we've appended to buffer */
|
|
totallen = buffer->len - base_offset;
|
|
|
|
/* Check length again, since we didn't include the metadata above */
|
|
if (totallen > JENTRY_OFFLENMASK)
|
|
ereport(ERROR,
|
|
(errcode(ERRCODE_PROGRAM_LIMIT_EXCEEDED),
|
|
errmsg("total size of jsonb array elements exceeds the maximum of %u bytes",
|
|
JENTRY_OFFLENMASK)));
|
|
|
|
/* Initialize the header of this node in the container's JEntry array */
|
|
*pheader = JENTRY_ISCONTAINER | totallen;
|
|
}
|
|
|
|
static void
|
|
convertJsonbObject(StringInfo buffer, JEntry *pheader, JsonbValue *val, int level)
|
|
{
|
|
int base_offset;
|
|
int jentry_offset;
|
|
int i;
|
|
int totallen;
|
|
uint32 header;
|
|
int nPairs = val->val.object.nPairs;
|
|
|
|
/* Remember where in the buffer this object starts. */
|
|
base_offset = buffer->len;
|
|
|
|
/* Align to 4-byte boundary (any padding counts as part of my data) */
|
|
padBufferToInt(buffer);
|
|
|
|
/*
|
|
* Construct the header Jentry and store it in the beginning of the
|
|
* variable-length payload.
|
|
*/
|
|
header = nPairs | JB_FOBJECT;
|
|
appendToBuffer(buffer, (char *) &header, sizeof(uint32));
|
|
|
|
/* Reserve space for the JEntries of the keys and values. */
|
|
jentry_offset = reserveFromBuffer(buffer, sizeof(JEntry) * nPairs * 2);
|
|
|
|
/*
|
|
* Iterate over the keys, then over the values, since that is the ordering
|
|
* we want in the on-disk representation.
|
|
*/
|
|
totallen = 0;
|
|
for (i = 0; i < nPairs; i++)
|
|
{
|
|
JsonbPair *pair = &val->val.object.pairs[i];
|
|
int len;
|
|
JEntry meta;
|
|
|
|
/*
|
|
* Convert key, producing a JEntry and appending its variable-length
|
|
* data to buffer
|
|
*/
|
|
convertJsonbScalar(buffer, &meta, &pair->key);
|
|
|
|
len = JBE_OFFLENFLD(meta);
|
|
totallen += len;
|
|
|
|
/*
|
|
* Bail out if total variable-length data exceeds what will fit in a
|
|
* JEntry length field. We check this in each iteration, not just
|
|
* once at the end, to forestall possible integer overflow.
|
|
*/
|
|
if (totallen > JENTRY_OFFLENMASK)
|
|
ereport(ERROR,
|
|
(errcode(ERRCODE_PROGRAM_LIMIT_EXCEEDED),
|
|
errmsg("total size of jsonb object elements exceeds the maximum of %u bytes",
|
|
JENTRY_OFFLENMASK)));
|
|
|
|
/*
|
|
* Convert each JB_OFFSET_STRIDE'th length to an offset.
|
|
*/
|
|
if ((i % JB_OFFSET_STRIDE) == 0)
|
|
meta = (meta & JENTRY_TYPEMASK) | totallen | JENTRY_HAS_OFF;
|
|
|
|
copyToBuffer(buffer, jentry_offset, (char *) &meta, sizeof(JEntry));
|
|
jentry_offset += sizeof(JEntry);
|
|
}
|
|
for (i = 0; i < nPairs; i++)
|
|
{
|
|
JsonbPair *pair = &val->val.object.pairs[i];
|
|
int len;
|
|
JEntry meta;
|
|
|
|
/*
|
|
* Convert value, producing a JEntry and appending its variable-length
|
|
* data to buffer
|
|
*/
|
|
convertJsonbValue(buffer, &meta, &pair->value, level + 1);
|
|
|
|
len = JBE_OFFLENFLD(meta);
|
|
totallen += len;
|
|
|
|
/*
|
|
* Bail out if total variable-length data exceeds what will fit in a
|
|
* JEntry length field. We check this in each iteration, not just
|
|
* once at the end, to forestall possible integer overflow.
|
|
*/
|
|
if (totallen > JENTRY_OFFLENMASK)
|
|
ereport(ERROR,
|
|
(errcode(ERRCODE_PROGRAM_LIMIT_EXCEEDED),
|
|
errmsg("total size of jsonb object elements exceeds the maximum of %u bytes",
|
|
JENTRY_OFFLENMASK)));
|
|
|
|
/*
|
|
* Convert each JB_OFFSET_STRIDE'th length to an offset.
|
|
*/
|
|
if (((i + nPairs) % JB_OFFSET_STRIDE) == 0)
|
|
meta = (meta & JENTRY_TYPEMASK) | totallen | JENTRY_HAS_OFF;
|
|
|
|
copyToBuffer(buffer, jentry_offset, (char *) &meta, sizeof(JEntry));
|
|
jentry_offset += sizeof(JEntry);
|
|
}
|
|
|
|
/* Total data size is everything we've appended to buffer */
|
|
totallen = buffer->len - base_offset;
|
|
|
|
/* Check length again, since we didn't include the metadata above */
|
|
if (totallen > JENTRY_OFFLENMASK)
|
|
ereport(ERROR,
|
|
(errcode(ERRCODE_PROGRAM_LIMIT_EXCEEDED),
|
|
errmsg("total size of jsonb object elements exceeds the maximum of %u bytes",
|
|
JENTRY_OFFLENMASK)));
|
|
|
|
/* Initialize the header of this node in the container's JEntry array */
|
|
*pheader = JENTRY_ISCONTAINER | totallen;
|
|
}
|
|
|
|
static void
|
|
convertJsonbScalar(StringInfo buffer, JEntry *jentry, JsonbValue *scalarVal)
|
|
{
|
|
int numlen;
|
|
short padlen;
|
|
|
|
switch (scalarVal->type)
|
|
{
|
|
case jbvNull:
|
|
*jentry = JENTRY_ISNULL;
|
|
break;
|
|
|
|
case jbvString:
|
|
appendToBuffer(buffer, scalarVal->val.string.val, scalarVal->val.string.len);
|
|
|
|
*jentry = scalarVal->val.string.len;
|
|
break;
|
|
|
|
case jbvNumeric:
|
|
numlen = VARSIZE_ANY(scalarVal->val.numeric);
|
|
padlen = padBufferToInt(buffer);
|
|
|
|
appendToBuffer(buffer, (char *) scalarVal->val.numeric, numlen);
|
|
|
|
*jentry = JENTRY_ISNUMERIC | (padlen + numlen);
|
|
break;
|
|
|
|
case jbvBool:
|
|
*jentry = (scalarVal->val.boolean) ?
|
|
JENTRY_ISBOOL_TRUE : JENTRY_ISBOOL_FALSE;
|
|
break;
|
|
|
|
default:
|
|
elog(ERROR, "invalid jsonb scalar type");
|
|
}
|
|
}
|
|
|
|
/*
|
|
* Compare two jbvString JsonbValue values, a and b.
|
|
*
|
|
* This is a special qsort() comparator used to sort strings in certain
|
|
* internal contexts where it is sufficient to have a well-defined sort order.
|
|
* In particular, object pair keys are sorted according to this criteria to
|
|
* facilitate cheap binary searches where we don't care about lexical sort
|
|
* order.
|
|
*
|
|
* a and b are first sorted based on their length. If a tie-breaker is
|
|
* required, only then do we consider string binary equality.
|
|
*/
|
|
static int
|
|
lengthCompareJsonbStringValue(const void *a, const void *b)
|
|
{
|
|
const JsonbValue *va = (const JsonbValue *) a;
|
|
const JsonbValue *vb = (const JsonbValue *) b;
|
|
int res;
|
|
|
|
Assert(va->type == jbvString);
|
|
Assert(vb->type == jbvString);
|
|
|
|
if (va->val.string.len == vb->val.string.len)
|
|
{
|
|
res = memcmp(va->val.string.val, vb->val.string.val, va->val.string.len);
|
|
}
|
|
else
|
|
{
|
|
res = (va->val.string.len > vb->val.string.len) ? 1 : -1;
|
|
}
|
|
|
|
return res;
|
|
}
|
|
|
|
/*
|
|
* qsort_arg() comparator to compare JsonbPair values.
|
|
*
|
|
* Third argument 'binequal' may point to a bool. If it's set, *binequal is set
|
|
* to true iff a and b have full binary equality, since some callers have an
|
|
* interest in whether the two values are equal or merely equivalent.
|
|
*
|
|
* N.B: String comparisons here are "length-wise"
|
|
*
|
|
* Pairs with equals keys are ordered such that the order field is respected.
|
|
*/
|
|
static int
|
|
lengthCompareJsonbPair(const void *a, const void *b, void *binequal)
|
|
{
|
|
const JsonbPair *pa = (const JsonbPair *) a;
|
|
const JsonbPair *pb = (const JsonbPair *) b;
|
|
int res;
|
|
|
|
res = lengthCompareJsonbStringValue(&pa->key, &pb->key);
|
|
if (res == 0 && binequal)
|
|
*((bool *) binequal) = true;
|
|
|
|
/*
|
|
* Guarantee keeping order of equal pair. Unique algorithm will prefer
|
|
* first element as value.
|
|
*/
|
|
if (res == 0)
|
|
res = (pa->order > pb->order) ? -1 : 1;
|
|
|
|
return res;
|
|
}
|
|
|
|
/*
|
|
* Sort and unique-ify pairs in JsonbValue object
|
|
*/
|
|
static void
|
|
uniqueifyJsonbObject(JsonbValue *object)
|
|
{
|
|
bool hasNonUniq = false;
|
|
|
|
Assert(object->type == jbvObject);
|
|
|
|
if (object->val.object.nPairs > 1)
|
|
qsort_arg(object->val.object.pairs, object->val.object.nPairs, sizeof(JsonbPair),
|
|
lengthCompareJsonbPair, &hasNonUniq);
|
|
|
|
if (hasNonUniq)
|
|
{
|
|
JsonbPair *ptr = object->val.object.pairs + 1,
|
|
*res = object->val.object.pairs;
|
|
|
|
while (ptr - object->val.object.pairs < object->val.object.nPairs)
|
|
{
|
|
/* Avoid copying over duplicate */
|
|
if (lengthCompareJsonbStringValue(ptr, res) != 0)
|
|
{
|
|
res++;
|
|
if (ptr != res)
|
|
memcpy(res, ptr, sizeof(JsonbPair));
|
|
}
|
|
ptr++;
|
|
}
|
|
|
|
object->val.object.nPairs = res + 1 - object->val.object.pairs;
|
|
}
|
|
}
|