json.h File Reference

#include "lib/stringinfo.h"

Include dependency graph for json.h:

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Go to the source code of this file.

Functions
void	composite_to_json (Datum composite, StringInfo result, bool use_line_feeds)
void	escape_json (StringInfo buf, const char *str)
void	escape_json_with_len (StringInfo buf, const char *str, int len)
void	escape_json_text (StringInfo buf, const text *txt)
char *	JsonEncodeDateTime (char *buf, Datum value, Oid typid, const int *tzp)
bool	to_json_is_immutable (Oid typoid)
Datum	json_build_object_worker (int nargs, const Datum *args, const bool *nulls, const Oid *types, bool absent_on_null, bool unique_keys)
Datum	json_build_array_worker (int nargs, const Datum *args, const bool *nulls, const Oid *types, bool absent_on_null)
bool	json_validate (text *json, bool check_unique_keys, bool throw_error)

Function Documentation

composite_to_json()

void composite_to_json ( Datum  composite, StringInfo  result, bool  use_line_feeds  )

extern

Definition at line 521 of file json.c.

{
    HeapTupleHeader td;
    Oid         tupType;
    int32       tupTypmod;
    TupleDesc   tupdesc;
    HeapTupleData tmptup,
               *tuple;
    int         i;
    bool        needsep = false;
    const char *sep;
    int         seplen;
 
    /*
     * We can avoid expensive strlen() calls by precalculating the separator
     * length.
     */
    sep = use_line_feeds ? ",\n " : ",";
    seplen = use_line_feeds ? strlen(",\n ") : strlen(",");
 
    td = DatumGetHeapTupleHeader(composite);
 
    /* Extract rowtype info and find a tupdesc */
    tupType = HeapTupleHeaderGetTypeId(td);
    tupTypmod = HeapTupleHeaderGetTypMod(td);
    tupdesc = lookup_rowtype_tupdesc(tupType, tupTypmod);
 
    /* Build a temporary HeapTuple control structure */
    tmptup.t_len = HeapTupleHeaderGetDatumLength(td);
    tmptup.t_data = td;
    tuple = &tmptup;
 
    appendStringInfoChar(result, '{');
 
    for (i = 0; i < tupdesc->natts; i++)
    {
        Datum       val;
        bool        isnull;
        char       *attname;
        JsonTypeCategory tcategory;
        Oid         outfuncoid;
        Form_pg_attribute att = TupleDescAttr(tupdesc, i);
 
        if (att->attisdropped)
            continue;
 
        if (needsep)
            appendBinaryStringInfo(result, sep, seplen);
        needsep = true;
 
        attname = NameStr(att->attname);
        escape_json(result, attname);
        appendStringInfoChar(result, ':');
 
        val = heap_getattr(tuple, i + 1, tupdesc, &isnull);
 
        if (isnull)
        {
            tcategory = JSONTYPE_NULL;
            outfuncoid = InvalidOid;
        }
        else
            json_categorize_type(att->atttypid, false, &tcategory,
                                 &outfuncoid);
 
        datum_to_json_internal(val, isnull, result, tcategory, outfuncoid,
                               false);
    }
 
    appendStringInfoChar(result, '}');
    ReleaseTupleDesc(tupdesc);
}

References appendBinaryStringInfo(), appendStringInfoChar(), attname, datum_to_json_internal(), DatumGetHeapTupleHeader, escape_json(), fb(), heap_getattr(), HeapTupleHeaderGetDatumLength(), HeapTupleHeaderGetTypeId(), HeapTupleHeaderGetTypMod(), i, InvalidOid, json_categorize_type(), JSONTYPE_NULL, lookup_rowtype_tupdesc(), NameStr, TupleDescData::natts, ReleaseTupleDesc, TupleDescAttr(), and val.

Referenced by CopyToJsonOneRow(), datum_to_json_internal(), row_to_json(), and row_to_json_pretty().

escape_json()

void escape_json ( StringInfo  buf, const char *  str  )

extern

Definition at line 1572 of file json.c.

{
    appendStringInfoCharMacro(buf, '"');
 
    for (; *str != '\0'; str++)
        escape_json_char(buf, *str);
 
    appendStringInfoCharMacro(buf, '"');
}

References appendStringInfoCharMacro, buf, escape_json_char(), and str.

Referenced by appendJSONKeyValue(), composite_to_json(), datum_to_json_internal(), escape_yaml(), ExplainDummyGroup(), ExplainOpenGroup(), ExplainProperty(), ExplainPropertyList(), ExplainPropertyListNested(), generate_error_response(), populate_scalar(), sn_object_field_start(), sn_scalar(), transform_string_values_object_field_start(), transformJsonTableColumn(), and write_jsonlog().

escape_json_text()

void escape_json_text ( StringInfo  buf, const text *  txt  )

extern

Definition at line 1706 of file json.c.

{
    /* must cast away the const, unfortunately */
    text       *tunpacked = pg_detoast_datum_packed(unconstify(text *, txt));
    int         len = VARSIZE_ANY_EXHDR(tunpacked);
    char       *str;
 
    str = VARDATA_ANY(tunpacked);
 
    escape_json_with_len(buf, str, len);
 
    /* pfree any detoasted values */
    if (tunpacked != txt)
        pfree(tunpacked);
}

References buf, escape_json_with_len(), fb(), len, pfree(), pg_detoast_datum_packed(), str, unconstify, VARDATA_ANY(), and VARSIZE_ANY_EXHDR().

Referenced by datum_to_json_internal(), json_object(), json_object_two_arg(), and transform_string_values_scalar().

escape_json_with_len()

void escape_json_with_len ( StringInfo  buf, const char *  str, int  len  )

extern

Definition at line 1601 of file json.c.

{
    int         vlen;
 
    Assert(len >= 0);
 
    /*
     * Since we know the minimum length we'll need to append, let's just
     * enlarge the buffer now rather than incrementally making more space when
     * we run out.  Add two extra bytes for the enclosing quotes.
     */
    enlargeStringInfo(buf, len + 2);
 
    /*
     * Figure out how many bytes to process using SIMD.  Round 'len' down to
     * the previous multiple of sizeof(Vector8), assuming that's a power-of-2.
     */
    vlen = len & (int) (~(sizeof(Vector8) - 1));
 
    appendStringInfoCharMacro(buf, '"');
 
    for (int i = 0, copypos = 0;;)
    {
        /*
         * To speed this up, try searching sizeof(Vector8) bytes at once for
         * special characters that we need to escape.  When we find one, we
         * fall out of the Vector8 loop and copy the portion we've vector
         * searched and then we process sizeof(Vector8) bytes one byte at a
         * time.  Once done, come back and try doing vector searching again.
         * We'll also process any remaining bytes at the tail end of the
         * string byte-by-byte.  This optimization assumes that most chunks of
         * sizeof(Vector8) bytes won't contain any special characters.
         */
        for (; i < vlen; i += sizeof(Vector8))
        {
            Vector8     chunk;
 
            vector8_load(&chunk, (const uint8 *) &str[i]);
 
            /*
             * Break on anything less than ' ' or if we find a '"' or '\\'.
             * Those need special handling.  That's done in the per-byte loop.
             */
            if (vector8_has_le(chunk, (unsigned char) 0x1F) ||
                vector8_has(chunk, (unsigned char) '"') ||
                vector8_has(chunk, (unsigned char) '\\'))
                break;
 
#ifdef ESCAPE_JSON_FLUSH_AFTER
 
            /*
             * Flush what's been checked so far out to the destination buffer
             * every so often to avoid having to re-read cachelines when
             * escaping large strings.
             */
            if (i - copypos >= ESCAPE_JSON_FLUSH_AFTER)
            {
                appendBinaryStringInfo(buf, &str[copypos], i - copypos);
                copypos = i;
            }
#endif
        }
 
        /*
         * Write to the destination up to the point that we've vector searched
         * so far.  Do this only when switching into per-byte mode rather than
         * once every sizeof(Vector8) bytes.
         */
        if (copypos < i)
        {
            appendBinaryStringInfo(buf, &str[copypos], i - copypos);
            copypos = i;
        }
 
        /*
         * Per-byte loop for Vector8s containing special chars and for
         * processing the tail of the string.
         */
        for (int b = 0; b < sizeof(Vector8); b++)
        {
            /* check if we've finished */
            if (i == len)
                goto done;
 
            Assert(i < len);
 
            escape_json_char(buf, str[i++]);
        }
 
        copypos = i;
        /* We're not done yet.  Try the vector search again. */
    }
 
done:
    appendStringInfoCharMacro(buf, '"');
}

References appendBinaryStringInfo(), appendStringInfoCharMacro, Assert, b, buf, enlargeStringInfo(), escape_json_char(), ESCAPE_JSON_FLUSH_AFTER, fb(), i, len, str, vector8_has(), vector8_has_le(), and vector8_load().

Referenced by AddFileToBackupManifest(), escape_json_text(), hstore_to_json(), hstore_to_json_loose(), jsonb_put_escaped_value(), populate_scalar(), and printJsonPathItem().

json_build_array_worker()

Datum json_build_array_worker ( int  nargs, const Datum *  args, const bool *  nulls, const Oid *  types, bool  absent_on_null  )

extern

Definition at line 1314 of file json.c.

{
    int         i;
    const char *sep = "";
    StringInfoData result;
 
    initStringInfo(&result);
 
    appendStringInfoChar(&result, '[');
 
    for (i = 0; i < nargs; i++)
    {
        if (absent_on_null && nulls[i])
            continue;
 
        appendStringInfoString(&result, sep);
        sep = ", ";
        add_json(args[i], nulls[i], &result, types[i], false);
    }
 
    appendStringInfoChar(&result, ']');
 
    return PointerGetDatum(cstring_to_text_with_len(result.data, result.len));
}

References add_json(), appendStringInfoChar(), appendStringInfoString(), cstring_to_text_with_len(), StringInfoData::data, fb(), i, initStringInfo(), StringInfoData::len, PointerGetDatum(), and types.

Referenced by ExecEvalJsonConstructor(), and json_build_array().

json_build_object_worker()

Datum json_build_object_worker ( int  nargs, const Datum *  args, const bool *  nulls, const Oid *  types, bool  absent_on_null, bool  unique_keys  )

extern

Definition at line 1194 of file json.c.

{
    int         i;
    const char *sep = "";
    StringInfo  result;
    JsonUniqueBuilderState unique_check;
 
    if (nargs % 2 != 0)
        ereport(ERROR,
                (errcode(ERRCODE_INVALID_PARAMETER_VALUE),
                 errmsg("argument list must have even number of elements"),
        /* translator: %s is a SQL function name */
                 errhint("The arguments of %s must consist of alternating keys and values.",
                         "json_build_object()")));
 
    result = makeStringInfo();
 
    appendStringInfoChar(result, '{');
 
    if (unique_keys)
        json_unique_builder_init(&unique_check);
 
    for (i = 0; i < nargs; i += 2)
    {
        StringInfo  out;
        bool        skip;
        int         key_offset;
 
        /* Skip null values if absent_on_null */
        skip = absent_on_null && nulls[i + 1];
 
        if (skip)
        {
            /* If key uniqueness check is needed we must save skipped keys */
            if (!unique_keys)
                continue;
 
            out = json_unique_builder_get_throwawaybuf(&unique_check);
        }
        else
        {
            appendStringInfoString(result, sep);
            sep = ", ";
            out = result;
        }
 
        /* process key */
        if (nulls[i])
            ereport(ERROR,
                    (errcode(ERRCODE_NULL_VALUE_NOT_ALLOWED),
                     errmsg("null value not allowed for object key")));
 
        /* save key offset before appending it */
        key_offset = out->len;
 
        add_json(args[i], false, out, types[i], true);
 
        if (unique_keys)
        {
            /*
             * check key uniqueness after key appending
             *
             * Copy the key first, instead of pointing into the buffer. It
             * will be added to the hash table, but the buffer may get
             * reallocated as we're appending more data to it. That would
             * invalidate pointers to keys in the current buffer.
             */
            const char *key = pstrdup(&out->data[key_offset]);
 
            if (!json_unique_check_key(&unique_check.check, key, 0))
                ereport(ERROR,
                        errcode(ERRCODE_DUPLICATE_JSON_OBJECT_KEY_VALUE),
                        errmsg("duplicate JSON object key value: %s", key));
 
            if (skip)
                continue;
        }
 
        appendStringInfoString(result, " : ");
 
        /* process value */
        add_json(args[i + 1], nulls[i + 1], result, types[i + 1], false);
    }
 
    appendStringInfoChar(result, '}');
 
    return PointerGetDatum(cstring_to_text_with_len(result->data, result->len));
}

References add_json(), appendStringInfoChar(), appendStringInfoString(), JsonUniqueBuilderState::check, cstring_to_text_with_len(), StringInfoData::data, ereport, errcode(), errhint(), errmsg, ERROR, fb(), i, json_unique_builder_get_throwawaybuf(), json_unique_builder_init(), json_unique_check_key(), StringInfoData::len, makeStringInfo(), PointerGetDatum(), pstrdup(), skip, and types.

Referenced by ExecEvalJsonConstructor(), and json_build_object().

json_validate()

bool json_validate ( text *  json, bool  check_unique_keys, bool  throw_error  )

extern

Definition at line 1782 of file json.c.

{
    JsonLexContext lex;
    JsonSemAction uniqueSemAction = {0};
    JsonUniqueParsingState state;
    JsonParseErrorType result;
 
    makeJsonLexContext(&lex, json, check_unique_keys);
 
    if (check_unique_keys)
    {
        state.lex = &lex;
        state.stack = NULL;
        state.id_counter = 0;
        state.unique = true;
        json_unique_check_init(&state.check);
 
        uniqueSemAction.semstate = &state;
        uniqueSemAction.object_start = json_unique_object_start;
        uniqueSemAction.object_field_start = json_unique_object_field_start;
        uniqueSemAction.object_end = json_unique_object_end;
    }
 
    result = pg_parse_json(&lex, check_unique_keys ? &uniqueSemAction : &nullSemAction);
 
    if (result != JSON_SUCCESS)
    {
        if (throw_error)
            json_errsave_error(result, &lex, NULL);
 
        return false;           /* invalid json */
    }
 
    if (check_unique_keys && !state.unique)
    {
        if (throw_error)
            ereport(ERROR,
                    (errcode(ERRCODE_DUPLICATE_JSON_OBJECT_KEY_VALUE),
                     errmsg("duplicate JSON object key value")));
 
        return false;           /* not unique keys */
    }
 
    if (check_unique_keys)
        freeJsonLexContext(&lex);
 
    return true;                /* ok */
}

References ereport, errcode(), errmsg, ERROR, fb(), freeJsonLexContext(), json_errsave_error(), JSON_SUCCESS, json_unique_check_init(), json_unique_object_end(), json_unique_object_field_start(), json_unique_object_start(), makeJsonLexContext(), nullSemAction, and pg_parse_json().

Referenced by ExecEvalJsonConstructor(), and ExecEvalJsonIsPredicate().

JsonEncodeDateTime()

char * JsonEncodeDateTime ( char *  buf, Datum  value, Oid  typid, const int *  tzp  )

extern

Definition at line 309 of file json.c.

{
    if (!buf)
        buf = palloc(MAXDATELEN + 1);
 
    switch (typid)
    {
        case DATEOID:
            {
                DateADT     date;
                struct pg_tm tm;
 
                date = DatumGetDateADT(value);
 
                /* Same as date_out(), but forcing DateStyle */
                if (DATE_NOT_FINITE(date))
                    EncodeSpecialDate(date, buf);
                else
                {
                    j2date(date + POSTGRES_EPOCH_JDATE,
                           &(tm.tm_year), &(tm.tm_mon), &(tm.tm_mday));
                    EncodeDateOnly(&tm, USE_XSD_DATES, buf);
                }
            }
            break;
        case TIMEOID:
            {
                TimeADT     time = DatumGetTimeADT(value);
                struct pg_tm tt,
                           *tm = &tt;
                fsec_t      fsec;
 
                /* Same as time_out(), but forcing DateStyle */
                time2tm(time, tm, &fsec);
                EncodeTimeOnly(tm, fsec, false, 0, USE_XSD_DATES, buf);
            }
            break;
        case TIMETZOID:
            {
                TimeTzADT  *time = DatumGetTimeTzADTP(value);
                struct pg_tm tt,
                           *tm = &tt;
                fsec_t      fsec;
                int         tz;
 
                /* Same as timetz_out(), but forcing DateStyle */
                timetz2tm(time, tm, &fsec, &tz);
                EncodeTimeOnly(tm, fsec, true, tz, USE_XSD_DATES, buf);
            }
            break;
        case TIMESTAMPOID:
            {
                Timestamp   timestamp;
                struct pg_tm tm;
                fsec_t      fsec;
 
                timestamp = DatumGetTimestamp(value);
                /* Same as timestamp_out(), but forcing DateStyle */
                if (TIMESTAMP_NOT_FINITE(timestamp))
                    EncodeSpecialTimestamp(timestamp, buf);
                else if (timestamp2tm(timestamp, NULL, &tm, &fsec, NULL, NULL) == 0)
                    EncodeDateTime(&tm, fsec, false, 0, NULL, USE_XSD_DATES, buf);
                else
                    ereport(ERROR,
                            (errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
                             errmsg("timestamp out of range")));
            }
            break;
        case TIMESTAMPTZOID:
            {
                TimestampTz timestamp;
                struct pg_tm tm;
                int         tz;
                fsec_t      fsec;
                const char *tzn = NULL;
 
                timestamp = DatumGetTimestampTz(value);
 
                /*
                 * If a time zone is specified, we apply the time-zone shift,
                 * convert timestamptz to pg_tm as if it were without a time
                 * zone, and then use the specified time zone for converting
                 * the timestamp into a string.
                 */
                if (tzp)
                {
                    tz = *tzp;
                    timestamp -= (TimestampTz) tz * USECS_PER_SEC;
                }
 
                /* Same as timestamptz_out(), but forcing DateStyle */
                if (TIMESTAMP_NOT_FINITE(timestamp))
                    EncodeSpecialTimestamp(timestamp, buf);
                else if (timestamp2tm(timestamp, tzp ? NULL : &tz, &tm, &fsec,
                                      tzp ? NULL : &tzn, NULL) == 0)
                {
                    if (tzp)
                        tm.tm_isdst = 1;    /* set time-zone presence flag */
 
                    EncodeDateTime(&tm, fsec, true, tz, tzn, USE_XSD_DATES, buf);
                }
                else
                    ereport(ERROR,
                            (errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
                             errmsg("timestamp out of range")));
            }
            break;
        default:
            elog(ERROR, "unknown jsonb value datetime type oid %u", typid);
            return NULL;
    }
 
    return buf;
}

References buf, DATE_NOT_FINITE, DatumGetDateADT(), DatumGetTimeADT(), DatumGetTimestamp(), DatumGetTimestampTz(), DatumGetTimeTzADTP(), elog, EncodeDateOnly(), EncodeDateTime(), EncodeSpecialDate(), EncodeSpecialTimestamp(), EncodeTimeOnly(), ereport, errcode(), errmsg, ERROR, fb(), j2date(), MAXDATELEN, palloc(), POSTGRES_EPOCH_JDATE, time2tm(), timestamp2tm(), TIMESTAMP_NOT_FINITE, timetz2tm(), tm, pg_tm::tm_isdst, pg_tm::tm_mday, pg_tm::tm_mon, pg_tm::tm_year, USE_XSD_DATES, USECS_PER_SEC, and value.

Referenced by convertJsonbScalar(), datum_to_json_internal(), datum_to_jsonb_internal(), and executeItemOptUnwrapTarget().

to_json_is_immutable()

bool to_json_is_immutable ( Oid  typoid )

extern

Definition at line 696 of file json.c.

{
    bool        has_mutable = false;
 
    json_check_mutability(typoid, false, &has_mutable);
    return !has_mutable;
}

References fb(), and json_check_mutability().

Referenced by contain_mutable_functions_walker().