/src/postgres/src/backend/utils/adt/jsonb.c

Source
/*-------------------------------------------------------------------------
 *
 * jsonb.c
 *    I/O routines for jsonb type
 *
 * Copyright (c) 2014-2026, PostgreSQL Global Development Group
 *
 * IDENTIFICATION
 *    src/backend/utils/adt/jsonb.c
 *
 *-------------------------------------------------------------------------
 */
#include "postgres.h"

#include "access/htup_details.h"
#include "catalog/pg_type.h"
#include "funcapi.h"
#include "libpq/pqformat.h"
#include "miscadmin.h"
#include "utils/builtins.h"
#include "utils/fmgroids.h"
#include "utils/json.h"
#include "utils/jsonb.h"
#include "utils/jsonfuncs.h"
#include "utils/lsyscache.h"
#include "utils/typcache.h"

typedef struct JsonbAggState
{
  JsonbInState pstate;
  JsonTypeCategory key_category;
  Oid     key_output_func;
  JsonTypeCategory val_category;
  Oid     val_output_func;
} JsonbAggState;

static inline Datum jsonb_from_cstring(char *json, int len, bool unique_keys,
                     Node *escontext);
static bool checkStringLen(size_t len, Node *escontext);
static JsonParseErrorType jsonb_in_object_start(void *pstate);
static JsonParseErrorType jsonb_in_object_end(void *pstate);
static JsonParseErrorType jsonb_in_array_start(void *pstate);
static JsonParseErrorType jsonb_in_array_end(void *pstate);
static JsonParseErrorType jsonb_in_object_field_start(void *pstate, char *fname, bool isnull);
static void jsonb_put_escaped_value(StringInfo out, JsonbValue *scalarVal);
static JsonParseErrorType jsonb_in_scalar(void *pstate, char *token, JsonTokenType tokentype);
static void composite_to_jsonb(Datum composite, JsonbInState *result);
static void array_dim_to_jsonb(JsonbInState *result, int dim, int ndims, int *dims,
                 const Datum *vals, const bool *nulls, int *valcount,
                 JsonTypeCategory tcategory, Oid outfuncoid);
static void array_to_jsonb_internal(Datum array, JsonbInState *result);
static void datum_to_jsonb_internal(Datum val, bool is_null, JsonbInState *result,
                  JsonTypeCategory tcategory, Oid outfuncoid,
                  bool key_scalar);
static void add_jsonb(Datum val, bool is_null, JsonbInState *result,
            Oid val_type, bool key_scalar);
static char *JsonbToCStringWorker(StringInfo out, JsonbContainer *in, int estimated_len, bool indent);
static void add_indent(StringInfo out, bool indent, int level);

/*
 * jsonb type input function
 */
Datum
jsonb_in(PG_FUNCTION_ARGS)
{
  char     *json = PG_GETARG_CSTRING(0);

  return jsonb_from_cstring(json, strlen(json), false, fcinfo->context);
}

/*
 * jsonb type recv function
 *
 * The type is sent as text in binary mode, so this is almost the same
 * as the input function, but it's prefixed with a version number so we
 * can change the binary format sent in future if necessary. For now,
 * only version 1 is supported.
 */
Datum
jsonb_recv(PG_FUNCTION_ARGS)
{
  StringInfo  buf = (StringInfo) PG_GETARG_POINTER(0);
  int     version = pq_getmsgint(buf, 1);
  char     *str;
  int     nbytes;

  if (version == 1)
    str = pq_getmsgtext(buf, buf->len - buf->cursor, &nbytes);
  else
    elog(ERROR, "unsupported jsonb version number %d", version);

  return jsonb_from_cstring(str, nbytes, false, NULL);
}

/*
 * jsonb type output function
 */
Datum
jsonb_out(PG_FUNCTION_ARGS)
{
  Jsonb    *jb = PG_GETARG_JSONB_P(0);
  char     *out;

  out = JsonbToCString(NULL, &jb->root, VARSIZE(jb));

  PG_RETURN_CSTRING(out);
}

/*
 * jsonb type send function
 *
 * Just send jsonb as a version number, then a string of text
 */
Datum
jsonb_send(PG_FUNCTION_ARGS)
{
  Jsonb    *jb = PG_GETARG_JSONB_P(0);
  StringInfoData buf;
  StringInfoData jtext;
  int     version = 1;

  initStringInfo(&jtext);
  (void) JsonbToCString(&jtext, &jb->root, VARSIZE(jb));

  pq_begintypsend(&buf);
  pq_sendint8(&buf, version);
  pq_sendtext(&buf, jtext.data, jtext.len);
  pfree(jtext.data);

  PG_RETURN_BYTEA_P(pq_endtypsend(&buf));
}

/*
 * jsonb_from_text
 *
 * Turns json text string into a jsonb Datum.
 */
Datum
jsonb_from_text(text *js, bool unique_keys)
{
  return jsonb_from_cstring(VARDATA_ANY(js),
                VARSIZE_ANY_EXHDR(js),
                unique_keys,
                NULL);
}

/*
 * Get the type name of a jsonb container.
 */
static const char *
JsonbContainerTypeName(JsonbContainer *jbc)
{
  JsonbValue  scalar;

  if (JsonbExtractScalar(jbc, &scalar))
    return JsonbTypeName(&scalar);
  else if (JsonContainerIsArray(jbc))
    return "array";
  else if (JsonContainerIsObject(jbc))
    return "object";
  else
  {
    elog(ERROR, "invalid jsonb container type: 0x%08x", jbc->header);
    return "unknown";
  }
}

/*
 * Get the type name of a jsonb value.
 */
const char *
JsonbTypeName(JsonbValue *val)
{
  switch (val->type)
  {
    case jbvBinary:
      return JsonbContainerTypeName(val->val.binary.data);
    case jbvObject:
      return "object";
    case jbvArray:
      return "array";
    case jbvNumeric:
      return "number";
    case jbvString:
      return "string";
    case jbvBool:
      return "boolean";
    case jbvNull:
      return "null";
    case jbvDatetime:
      switch (val->val.datetime.typid)
      {
        case DATEOID:
          return "date";
        case TIMEOID:
          return "time without time zone";
        case TIMETZOID:
          return "time with time zone";
        case TIMESTAMPOID:
          return "timestamp without time zone";
        case TIMESTAMPTZOID:
          return "timestamp with time zone";
        default:
          elog(ERROR, "unrecognized jsonb value datetime type: %d",
             val->val.datetime.typid);
      }
      return "unknown";
    default:
      elog(ERROR, "unrecognized jsonb value type: %d", val->type);
      return "unknown";
  }
}

/*
 * SQL function jsonb_typeof(jsonb) -> text
 *
 * This function is here because the analog json function is in json.c, since
 * it uses the json parser internals not exposed elsewhere.
 */
Datum
jsonb_typeof(PG_FUNCTION_ARGS)
{
  Jsonb    *in = PG_GETARG_JSONB_P(0);
  const char *result = JsonbContainerTypeName(&in->root);

  PG_RETURN_TEXT_P(cstring_to_text(result));
}

/*
 * jsonb_from_cstring
 *
 * Turns json string into a jsonb Datum.
 *
 * Uses the json parser (with hooks) to construct a jsonb.
 *
 * If escontext points to an ErrorSaveContext, errors are reported there
 * instead of being thrown.
 */
static inline Datum
jsonb_from_cstring(char *json, int len, bool unique_keys, Node *escontext)
{
  JsonLexContext lex;
  JsonbInState state;
  JsonSemAction sem;

  memset(&state, 0, sizeof(state));
  memset(&sem, 0, sizeof(sem));
  makeJsonLexContextCstringLen(&lex, json, len, GetDatabaseEncoding(), true);

  state.unique_keys = unique_keys;
  state.escontext = escontext;
  sem.semstate = &state;

  sem.object_start = jsonb_in_object_start;
  sem.array_start = jsonb_in_array_start;
  sem.object_end = jsonb_in_object_end;
  sem.array_end = jsonb_in_array_end;
  sem.scalar = jsonb_in_scalar;
  sem.object_field_start = jsonb_in_object_field_start;

  if (!pg_parse_json_or_errsave(&lex, &sem, escontext))
    return (Datum) 0;

  /* after parsing, the result field has the composed jsonb structure */
  PG_RETURN_POINTER(JsonbValueToJsonb(state.result));
}

static bool
checkStringLen(size_t len, Node *escontext)
{
  if (len > JENTRY_OFFLENMASK)
    ereturn(escontext, false,
        (errcode(ERRCODE_PROGRAM_LIMIT_EXCEEDED),
         errmsg("string too long to represent as jsonb string"),
         errdetail("Due to an implementation restriction, jsonb strings cannot exceed %d bytes.",
               JENTRY_OFFLENMASK)));

  return true;
}

static JsonParseErrorType
jsonb_in_object_start(void *pstate)
{
  JsonbInState *_state = (JsonbInState *) pstate;

  pushJsonbValue(_state, WJB_BEGIN_OBJECT, NULL);
  _state->parseState->unique_keys = _state->unique_keys;

  return JSON_SUCCESS;
}

static JsonParseErrorType
jsonb_in_object_end(void *pstate)
{
  JsonbInState *_state = (JsonbInState *) pstate;

  pushJsonbValue(_state, WJB_END_OBJECT, NULL);

  return JSON_SUCCESS;
}

static JsonParseErrorType
jsonb_in_array_start(void *pstate)
{
  JsonbInState *_state = (JsonbInState *) pstate;

  pushJsonbValue(_state, WJB_BEGIN_ARRAY, NULL);

  return JSON_SUCCESS;
}

static JsonParseErrorType
jsonb_in_array_end(void *pstate)
{
  JsonbInState *_state = (JsonbInState *) pstate;

  pushJsonbValue(_state, WJB_END_ARRAY, NULL);

  return JSON_SUCCESS;
}

static JsonParseErrorType
jsonb_in_object_field_start(void *pstate, char *fname, bool isnull)
{
  JsonbInState *_state = (JsonbInState *) pstate;
  JsonbValue  v;

  Assert(fname != NULL);
  v.type = jbvString;
  v.val.string.len = strlen(fname);
  if (!checkStringLen(v.val.string.len, _state->escontext))
    return JSON_SEM_ACTION_FAILED;
  v.val.string.val = fname;

  pushJsonbValue(_state, WJB_KEY, &v);

  return JSON_SUCCESS;
}

static void
jsonb_put_escaped_value(StringInfo out, JsonbValue *scalarVal)
{
  switch (scalarVal->type)
  {
    case jbvNull:
      appendBinaryStringInfo(out, "null", 4);
      break;
    case jbvString:
      escape_json_with_len(out, scalarVal->val.string.val, scalarVal->val.string.len);
      break;
    case jbvNumeric:
      appendStringInfoString(out,
                   DatumGetCString(DirectFunctionCall1(numeric_out,
                                     PointerGetDatum(scalarVal->val.numeric))));
      break;
    case jbvBool:
      if (scalarVal->val.boolean)
        appendBinaryStringInfo(out, "true", 4);
      else
        appendBinaryStringInfo(out, "false", 5);
      break;
    default:
      elog(ERROR, "unknown jsonb scalar type");
  }
}

/*
 * For jsonb we always want the de-escaped value - that's what's in token
 */
static JsonParseErrorType
jsonb_in_scalar(void *pstate, char *token, JsonTokenType tokentype)
{
  JsonbInState *_state = (JsonbInState *) pstate;
  JsonbValue  v;
  Datum   numd;

  switch (tokentype)
  {

    case JSON_TOKEN_STRING:
      Assert(token != NULL);
      v.type = jbvString;
      v.val.string.len = strlen(token);
      if (!checkStringLen(v.val.string.len, _state->escontext))
        return JSON_SEM_ACTION_FAILED;
      v.val.string.val = token;
      break;
    case JSON_TOKEN_NUMBER:

      /*
       * No need to check size of numeric values, because maximum
       * numeric size is well below the JsonbValue restriction
       */
      Assert(token != NULL);
      v.type = jbvNumeric;
      if (!DirectInputFunctionCallSafe(numeric_in, token,
                       InvalidOid, -1,
                       _state->escontext,
                       &numd))
        return JSON_SEM_ACTION_FAILED;
      v.val.numeric = DatumGetNumeric(numd);
      break;
    case JSON_TOKEN_TRUE:
      v.type = jbvBool;
      v.val.boolean = true;
      break;
    case JSON_TOKEN_FALSE:
      v.type = jbvBool;
      v.val.boolean = false;
      break;
    case JSON_TOKEN_NULL:
      v.type = jbvNull;
      break;
    default:
      /* should not be possible */
      elog(ERROR, "invalid json token type");
      break;
  }

  if (_state->parseState == NULL)
  {
    /* single scalar */
    JsonbValue  va;

    va.type = jbvArray;
    va.val.array.rawScalar = true;
    va.val.array.nElems = 1;

    pushJsonbValue(_state, WJB_BEGIN_ARRAY, &va);
    pushJsonbValue(_state, WJB_ELEM, &v);
    pushJsonbValue(_state, WJB_END_ARRAY, NULL);
  }
  else
  {
    JsonbValue *o = &_state->parseState->contVal;

    switch (o->type)
    {
      case jbvArray:
        pushJsonbValue(_state, WJB_ELEM, &v);
        break;
      case jbvObject:
        pushJsonbValue(_state, WJB_VALUE, &v);
        break;
      default:
        elog(ERROR, "unexpected parent of nested structure");
    }
  }

  return JSON_SUCCESS;
}

/*
 * JsonbToCString
 *     Converts jsonb value to a C-string.
 *
 * If 'out' argument is non-null, the resulting C-string is stored inside the
 * StringBuffer.  The resulting string is always returned.
 *
 * A typical case for passing the StringInfo in rather than NULL is where the
 * caller wants access to the len attribute without having to call strlen, e.g.
 * if they are converting it to a text* object.
 */
char *
JsonbToCString(StringInfo out, JsonbContainer *in, int estimated_len)
{
  return JsonbToCStringWorker(out, in, estimated_len, false);
}

/*
 * same thing but with indentation turned on
 */
char *
JsonbToCStringIndent(StringInfo out, JsonbContainer *in, int estimated_len)
{
  return JsonbToCStringWorker(out, in, estimated_len, true);
}

/*
 * common worker for above two functions
 */
static char *
JsonbToCStringWorker(StringInfo out, JsonbContainer *in, int estimated_len, bool indent)
{
  bool    first = true;
  JsonbIterator *it;
  JsonbValue  v;
  JsonbIteratorToken type = WJB_DONE;
  int     level = 0;
  bool    redo_switch = false;

  /* If we are indenting, don't add a space after a comma */
  int     ispaces = indent ? 1 : 2;

  /*
   * Don't indent the very first item. This gets set to the indent flag at
   * the bottom of the loop.
   */
  bool    use_indent = false;
  bool    raw_scalar = false;
  bool    last_was_key = false;

  if (out == NULL)
    out = makeStringInfo();

  enlargeStringInfo(out, (estimated_len >= 0) ? estimated_len : 64);

  it = JsonbIteratorInit(in);

  while (redo_switch ||
       ((type = JsonbIteratorNext(&it, &v, false)) != WJB_DONE))
  {
    redo_switch = false;
    switch (type)
    {
      case WJB_BEGIN_ARRAY:
        if (!first)
          appendBinaryStringInfo(out, ", ", ispaces);

        if (!v.val.array.rawScalar)
        {
          add_indent(out, use_indent && !last_was_key, level);
          appendStringInfoCharMacro(out, '[');
        }
        else
          raw_scalar = true;

        first = true;
        level++;
        break;
      case WJB_BEGIN_OBJECT:
        if (!first)
          appendBinaryStringInfo(out, ", ", ispaces);

        add_indent(out, use_indent && !last_was_key, level);
        appendStringInfoCharMacro(out, '{');

        first = true;
        level++;
        break;
      case WJB_KEY:
        if (!first)
          appendBinaryStringInfo(out, ", ", ispaces);
        first = true;

        add_indent(out, use_indent, level);

        /* json rules guarantee this is a string */
        jsonb_put_escaped_value(out, &v);
        appendBinaryStringInfo(out, ": ", 2);

        type = JsonbIteratorNext(&it, &v, false);
        if (type == WJB_VALUE)
        {
          first = false;
          jsonb_put_escaped_value(out, &v);
        }
        else
        {
          Assert(type == WJB_BEGIN_OBJECT || type == WJB_BEGIN_ARRAY);

          /*
           * We need to rerun the current switch() since we need to
           * output the object which we just got from the iterator
           * before calling the iterator again.
           */
          redo_switch = true;
        }
        break;
      case WJB_ELEM:
        if (!first)
          appendBinaryStringInfo(out, ", ", ispaces);
        first = false;

        if (!raw_scalar)
          add_indent(out, use_indent, level);
        jsonb_put_escaped_value(out, &v);
        break;
      case WJB_END_ARRAY:
        level--;
        if (!raw_scalar)
        {
          add_indent(out, use_indent, level);
          appendStringInfoCharMacro(out, ']');
        }
        first = false;
        break;
      case WJB_END_OBJECT:
        level--;
        add_indent(out, use_indent, level);
        appendStringInfoCharMacro(out, '}');
        first = false;
        break;
      default:
        elog(ERROR, "unknown jsonb iterator token type");
    }
    use_indent = indent;
    last_was_key = redo_switch;
  }

  Assert(level == 0);

  return out->data;
}

static void
add_indent(StringInfo out, bool indent, int level)
{
  if (indent)
  {
    appendStringInfoCharMacro(out, '\n');
    appendStringInfoSpaces(out, level * 4);
  }
}


/*
 * Turn a Datum into jsonb, adding it to the result JsonbInState.
 *
 * tcategory and outfuncoid are from a previous call to json_categorize_type,
 * except that if is_null is true then they can be invalid.
 *
 * If key_scalar is true, the value is stored as a key, so insist
 * it's of an acceptable type, and force it to be a jbvString.
 *
 * Note: currently, we assume that result->escontext is NULL and errors
 * will be thrown.
 */
static void
datum_to_jsonb_internal(Datum val, bool is_null, JsonbInState *result,
            JsonTypeCategory tcategory, Oid outfuncoid,
            bool key_scalar)
{
  char     *outputstr;
  Numeric   numeric_val;
  bool    numeric_to_string;
  JsonbValue  jb;
  bool    scalar_jsonb = false;

  check_stack_depth();

  /* Convert val to a JsonbValue in jb (in most cases) */
  if (is_null)
  {
    Assert(!key_scalar);
    jb.type = jbvNull;
  }
  else if (key_scalar &&
       (tcategory == JSONTYPE_ARRAY ||
        tcategory == JSONTYPE_COMPOSITE ||
        tcategory == JSONTYPE_JSON ||
        tcategory == JSONTYPE_JSONB ||
        tcategory == JSONTYPE_CAST))
  {
    ereport(ERROR,
        (errcode(ERRCODE_INVALID_PARAMETER_VALUE),
         errmsg("key value must be scalar, not array, composite, or json")));
  }
  else
  {
    switch (tcategory)
    {
      case JSONTYPE_ARRAY:
        array_to_jsonb_internal(val, result);
        break;
      case JSONTYPE_COMPOSITE:
        composite_to_jsonb(val, result);
        break;
      case JSONTYPE_BOOL:
        if (key_scalar)
        {
          outputstr = DatumGetBool(val) ? "true" : "false";
          jb.type = jbvString;
          jb.val.string.len = strlen(outputstr);
          jb.val.string.val = outputstr;
        }
        else
        {
          jb.type = jbvBool;
          jb.val.boolean = DatumGetBool(val);
        }
        break;
      case JSONTYPE_NUMERIC:
        if (key_scalar)
        {
          /* always stringify keys */
          numeric_to_string = true;
          numeric_val = NULL; /* pacify stupider compilers */
        }
        else
        {
          Datum   numd;

          switch (outfuncoid)
          {
            case F_NUMERIC_OUT:
              numeric_val = DatumGetNumeric(val);
              break;
            case F_INT2OUT:
              numeric_val = int64_to_numeric(DatumGetInt16(val));
              break;
            case F_INT4OUT:
              numeric_val = int64_to_numeric(DatumGetInt32(val));
              break;
            case F_INT8OUT:
              numeric_val = int64_to_numeric(DatumGetInt64(val));
              break;
#ifdef NOT_USED

              /*
               * Ideally we'd short-circuit these two cases
               * using float[48]_numeric.  However, those
               * functions are currently slower than the generic
               * coerce-via-I/O approach.  And they may round
               * off differently.  Until/unless that gets fixed,
               * continue to use coerce-via-I/O for floats.
               */
            case F_FLOAT4OUT:
              numd = DirectFunctionCall1(float4_numeric, val);
              numeric_val = DatumGetNumeric(numd);
              break;
            case F_FLOAT8OUT:
              numd = DirectFunctionCall1(float8_numeric, val);
              numeric_val = DatumGetNumeric(numd);
              break;
#endif
            default:
              outputstr = OidOutputFunctionCall(outfuncoid, val);
              numd = DirectFunctionCall3(numeric_in,
                             CStringGetDatum(outputstr),
                             ObjectIdGetDatum(InvalidOid),
                             Int32GetDatum(-1));
              numeric_val = DatumGetNumeric(numd);
              break;
          }
          /* Must convert to string if it's Inf or NaN */
          numeric_to_string = (numeric_is_inf(numeric_val) ||
                     numeric_is_nan(numeric_val));
        }
        if (numeric_to_string)
        {
          outputstr = OidOutputFunctionCall(outfuncoid, val);
          jb.type = jbvString;
          jb.val.string.len = strlen(outputstr);
          jb.val.string.val = outputstr;
        }
        else
        {
          jb.type = jbvNumeric;
          jb.val.numeric = numeric_val;
        }
        break;
      case JSONTYPE_DATE:
        jb.type = jbvString;
        jb.val.string.val = JsonEncodeDateTime(NULL, val,
                             DATEOID, NULL);
        jb.val.string.len = strlen(jb.val.string.val);
        break;
      case JSONTYPE_TIMESTAMP:
        jb.type = jbvString;
        jb.val.string.val = JsonEncodeDateTime(NULL, val,
                             TIMESTAMPOID, NULL);
        jb.val.string.len = strlen(jb.val.string.val);
        break;
      case JSONTYPE_TIMESTAMPTZ:
        jb.type = jbvString;
        jb.val.string.val = JsonEncodeDateTime(NULL, val,
                             TIMESTAMPTZOID, NULL);
        jb.val.string.len = strlen(jb.val.string.val);
        break;
      case JSONTYPE_CAST:
        /* cast to JSON, and then process as JSON */
        val = OidFunctionCall1(outfuncoid, val);
        pg_fallthrough;
      case JSONTYPE_JSON:
        {
          /* parse the json right into the existing result object */
          JsonLexContext lex;
          JsonSemAction sem;
          text     *json = DatumGetTextPP(val);

          makeJsonLexContext(&lex, json, true);

          memset(&sem, 0, sizeof(sem));

          sem.semstate = result;

          sem.object_start = jsonb_in_object_start;
          sem.array_start = jsonb_in_array_start;
          sem.object_end = jsonb_in_object_end;
          sem.array_end = jsonb_in_array_end;
          sem.scalar = jsonb_in_scalar;
          sem.object_field_start = jsonb_in_object_field_start;

          pg_parse_json_or_ereport(&lex, &sem);
          freeJsonLexContext(&lex);
        }
        break;
      case JSONTYPE_JSONB:
        {
          Jsonb    *jsonb = DatumGetJsonbP(val);
          JsonbIterator *it;

          it = JsonbIteratorInit(&jsonb->root);

          if (JB_ROOT_IS_SCALAR(jsonb))
          {
            (void) JsonbIteratorNext(&it, &jb, true);
            Assert(jb.type == jbvArray);
            (void) JsonbIteratorNext(&it, &jb, true);
            scalar_jsonb = true;
          }
          else
          {
            JsonbIteratorToken type;

            while ((type = JsonbIteratorNext(&it, &jb, false))
                 != WJB_DONE)
            {
              if (type == WJB_END_ARRAY || type == WJB_END_OBJECT ||
                type == WJB_BEGIN_ARRAY || type == WJB_BEGIN_OBJECT)
                pushJsonbValue(result, type, NULL);
              else
                pushJsonbValue(result, type, &jb);
            }
          }
        }
        break;
      default:
        /* special-case text types to save useless palloc/memcpy ops */
        if (outfuncoid == F_TEXTOUT ||
          outfuncoid == F_VARCHAROUT ||
          outfuncoid == F_BPCHAROUT)
        {
          text     *txt = DatumGetTextPP(val);

          jb.val.string.len = VARSIZE_ANY_EXHDR(txt);
          jb.val.string.val = VARDATA_ANY(txt);
        }
        else
        {
          outputstr = OidOutputFunctionCall(outfuncoid, val);
          jb.val.string.len = strlen(outputstr);
          jb.val.string.val = outputstr;
        }
        jb.type = jbvString;
        (void) checkStringLen(jb.val.string.len, NULL);
        break;
    }
  }

  /* Now insert jb into result, unless we did it recursively */
  if (!is_null && !scalar_jsonb &&
    tcategory >= JSONTYPE_JSON && tcategory <= JSONTYPE_CAST)
  {
    /* work has been done recursively */
    return;
  }
  else if (result->parseState == NULL)
  {
    /* single root scalar */
    JsonbValue  va;

    va.type = jbvArray;
    va.val.array.rawScalar = true;
    va.val.array.nElems = 1;

    pushJsonbValue(result, WJB_BEGIN_ARRAY, &va);
    pushJsonbValue(result, WJB_ELEM, &jb);
    pushJsonbValue(result, WJB_END_ARRAY, NULL);
  }
  else
  {
    JsonbValue *o = &result->parseState->contVal;

    switch (o->type)
    {
      case jbvArray:
        pushJsonbValue(result, WJB_ELEM, &jb);
        break;
      case jbvObject:
        pushJsonbValue(result,
                 key_scalar ? WJB_KEY : WJB_VALUE,
                 &jb);
        break;
      default:
        elog(ERROR, "unexpected parent of nested structure");
    }
  }
}

/*
 * Process a single dimension of an array.
 * If it's the innermost dimension, output the values, otherwise call
 * ourselves recursively to process the next dimension.
 */
static void
array_dim_to_jsonb(JsonbInState *result, int dim, int ndims, int *dims, const Datum *vals,
           const bool *nulls, int *valcount, JsonTypeCategory tcategory,
           Oid outfuncoid)
{
  int     i;

  Assert(dim < ndims);

  pushJsonbValue(result, WJB_BEGIN_ARRAY, NULL);

  for (i = 1; i <= dims[dim]; i++)
  {
    if (dim + 1 == ndims)
    {
      datum_to_jsonb_internal(vals[*valcount], nulls[*valcount], result, tcategory,
                  outfuncoid, false);
      (*valcount)++;
    }
    else
    {
      array_dim_to_jsonb(result, dim + 1, ndims, dims, vals, nulls,
                 valcount, tcategory, outfuncoid);
    }
  }

  pushJsonbValue(result, WJB_END_ARRAY, NULL);
}

/*
 * Turn an array into JSON.
 */
static void
array_to_jsonb_internal(Datum array, JsonbInState *result)
{
  ArrayType  *v = DatumGetArrayTypeP(array);
  Oid     element_type = ARR_ELEMTYPE(v);
  int      *dim;
  int     ndim;
  int     nitems;
  int     count = 0;
  Datum    *elements;
  bool     *nulls;
  int16   typlen;
  bool    typbyval;
  char    typalign;
  JsonTypeCategory tcategory;
  Oid     outfuncoid;

  ndim = ARR_NDIM(v);
  dim = ARR_DIMS(v);
  nitems = ArrayGetNItems(ndim, dim);

  if (nitems <= 0)
  {
    pushJsonbValue(result, WJB_BEGIN_ARRAY, NULL);
    pushJsonbValue(result, WJB_END_ARRAY, NULL);
    return;
  }

  get_typlenbyvalalign(element_type,
             &typlen, &typbyval, &typalign);

  json_categorize_type(element_type, true,
             &tcategory, &outfuncoid);

  deconstruct_array(v, element_type, typlen, typbyval,
            typalign, &elements, &nulls,
            &nitems);

  array_dim_to_jsonb(result, 0, ndim, dim, elements, nulls, &count, tcategory,
             outfuncoid);

  pfree(elements);
  pfree(nulls);
}

/*
 * Turn a composite / record into JSON.
 */
static void
composite_to_jsonb(Datum composite, JsonbInState *result)
{
  HeapTupleHeader td;
  Oid     tupType;
  int32   tupTypmod;
  TupleDesc tupdesc;
  HeapTupleData tmptup,
         *tuple;
  int     i;

  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;

  pushJsonbValue(result, WJB_BEGIN_OBJECT, NULL);

  for (i = 0; i < tupdesc->natts; i++)
  {
    Datum   val;
    bool    isnull;
    char     *attname;
    JsonTypeCategory tcategory;
    Oid     outfuncoid;
    JsonbValue  v;
    Form_pg_attribute att = TupleDescAttr(tupdesc, i);

    if (att->attisdropped)
      continue;

    attname = NameStr(att->attname);

    v.type = jbvString;
    /* don't need checkStringLen here - can't exceed maximum name length */
    v.val.string.len = strlen(attname);
    v.val.string.val = attname;

    pushJsonbValue(result, WJB_KEY, &v);

    val = heap_getattr(tuple, i + 1, tupdesc, &isnull);

    if (isnull)
    {
      tcategory = JSONTYPE_NULL;
      outfuncoid = InvalidOid;
    }
    else
      json_categorize_type(att->atttypid, true, &tcategory,
                 &outfuncoid);

    datum_to_jsonb_internal(val, isnull, result, tcategory, outfuncoid,
                false);
  }

  pushJsonbValue(result, WJB_END_OBJECT, NULL);
  ReleaseTupleDesc(tupdesc);
}

/*
 * Append JSON text for "val" to "result".
 *
 * This is just a thin wrapper around datum_to_jsonb.  If the same type will be
 * printed many times, avoid using this; better to do the json_categorize_type
 * lookups only once.
 */

static void
add_jsonb(Datum val, bool is_null, JsonbInState *result,
      Oid val_type, bool key_scalar)
{
  JsonTypeCategory tcategory;
  Oid     outfuncoid;

  if (val_type == InvalidOid)
    ereport(ERROR,
        (errcode(ERRCODE_INVALID_PARAMETER_VALUE),
         errmsg("could not determine input data type")));

  if (is_null)
  {
    tcategory = JSONTYPE_NULL;
    outfuncoid = InvalidOid;
  }
  else
    json_categorize_type(val_type, true,
               &tcategory, &outfuncoid);

  datum_to_jsonb_internal(val, is_null, result, tcategory, outfuncoid,
              key_scalar);
}


/*
 * Is the given type immutable when coming out of a JSONB context?
 */
bool
to_jsonb_is_immutable(Oid typoid)
{
  bool    has_mutable = false;

  json_check_mutability(typoid, true, &has_mutable);
  return !has_mutable;
}

/*
 * SQL function to_jsonb(anyvalue)
 */
Datum
to_jsonb(PG_FUNCTION_ARGS)
{
  Datum   val = PG_GETARG_DATUM(0);
  Oid     val_type = get_fn_expr_argtype(fcinfo->flinfo, 0);
  JsonTypeCategory tcategory;
  Oid     outfuncoid;

  if (val_type == InvalidOid)
    ereport(ERROR,
        (errcode(ERRCODE_INVALID_PARAMETER_VALUE),
         errmsg("could not determine input data type")));

  json_categorize_type(val_type, true,
             &tcategory, &outfuncoid);

  PG_RETURN_DATUM(datum_to_jsonb(val, tcategory, outfuncoid));
}

/*
 * Turn a Datum into jsonb.
 *
 * tcategory and outfuncoid are from a previous call to json_categorize_type.
 */
Datum
datum_to_jsonb(Datum val, JsonTypeCategory tcategory, Oid outfuncoid)
{
  JsonbInState result;

  memset(&result, 0, sizeof(JsonbInState));

  datum_to_jsonb_internal(val, false, &result, tcategory, outfuncoid,
              false);

  return JsonbPGetDatum(JsonbValueToJsonb(result.result));
}

Datum
jsonb_build_object_worker(int nargs, const Datum *args, const bool *nulls, const Oid *types,
              bool absent_on_null, bool unique_keys)
{
  int     i;
  JsonbInState result;

  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.",
             "jsonb_build_object()")));

  memset(&result, 0, sizeof(JsonbInState));

  pushJsonbValue(&result, WJB_BEGIN_OBJECT, NULL);
  result.parseState->unique_keys = unique_keys;
  result.parseState->skip_nulls = absent_on_null;

  for (i = 0; i < nargs; i += 2)
  {
    /* process key */
    bool    skip;

    if (nulls[i])
      ereport(ERROR,
          (errcode(ERRCODE_INVALID_PARAMETER_VALUE),
           errmsg("argument %d: key must not be null", i + 1)));

    /* skip null values if absent_on_null */
    skip = absent_on_null && nulls[i + 1];

    /* we need to save skipped keys for the key uniqueness check */
    if (skip && !unique_keys)
      continue;

    add_jsonb(args[i], false, &result, types[i], true);

    /* process value */
    add_jsonb(args[i + 1], nulls[i + 1], &result, types[i + 1], false);
  }

  pushJsonbValue(&result, WJB_END_OBJECT, NULL);

  return JsonbPGetDatum(JsonbValueToJsonb(result.result));
}

/*
 * SQL function jsonb_build_object(variadic "any")
 */
Datum
jsonb_build_object(PG_FUNCTION_ARGS)
{
  Datum    *args;
  bool     *nulls;
  Oid      *types;

  /* build argument values to build the object */
  int     nargs = extract_variadic_args(fcinfo, 0, true,
                        &args, &types, &nulls);

  if (nargs < 0)
    PG_RETURN_NULL();

  PG_RETURN_DATUM(jsonb_build_object_worker(nargs, args, nulls, types, false, false));
}

/*
 * degenerate case of jsonb_build_object where it gets 0 arguments.
 */
Datum
jsonb_build_object_noargs(PG_FUNCTION_ARGS)
{
  JsonbInState result;

  memset(&result, 0, sizeof(JsonbInState));

  pushJsonbValue(&result, WJB_BEGIN_OBJECT, NULL);
  pushJsonbValue(&result, WJB_END_OBJECT, NULL);

  PG_RETURN_POINTER(JsonbValueToJsonb(result.result));
}

Datum
jsonb_build_array_worker(int nargs, const Datum *args, const bool *nulls, const Oid *types,
             bool absent_on_null)
{
  int     i;
  JsonbInState result;

  memset(&result, 0, sizeof(JsonbInState));

  pushJsonbValue(&result, WJB_BEGIN_ARRAY, NULL);

  for (i = 0; i < nargs; i++)
  {
    if (absent_on_null && nulls[i])
      continue;

    add_jsonb(args[i], nulls[i], &result, types[i], false);
  }

  pushJsonbValue(&result, WJB_END_ARRAY, NULL);

  return JsonbPGetDatum(JsonbValueToJsonb(result.result));
}

/*
 * SQL function jsonb_build_array(variadic "any")
 */
Datum
jsonb_build_array(PG_FUNCTION_ARGS)
{
  Datum    *args;
  bool     *nulls;
  Oid      *types;

  /* build argument values to build the object */
  int     nargs = extract_variadic_args(fcinfo, 0, true,
                        &args, &types, &nulls);

  if (nargs < 0)
    PG_RETURN_NULL();

  PG_RETURN_DATUM(jsonb_build_array_worker(nargs, args, nulls, types, false));
}


/*
 * degenerate case of jsonb_build_array where it gets 0 arguments.
 */
Datum
jsonb_build_array_noargs(PG_FUNCTION_ARGS)
{
  JsonbInState result;

  memset(&result, 0, sizeof(JsonbInState));

  pushJsonbValue(&result, WJB_BEGIN_ARRAY, NULL);
  pushJsonbValue(&result, WJB_END_ARRAY, NULL);

  PG_RETURN_POINTER(JsonbValueToJsonb(result.result));
}


/*
 * SQL function jsonb_object(text[])
 *
 * take a one or two dimensional array of text as name value pairs
 * for a jsonb object.
 *
 */
Datum
jsonb_object(PG_FUNCTION_ARGS)
{
  ArrayType  *in_array = PG_GETARG_ARRAYTYPE_P(0);
  int     ndims = ARR_NDIM(in_array);
  Datum    *in_datums;
  bool     *in_nulls;
  int     in_count,
        count,
        i;
  JsonbInState result;

  memset(&result, 0, sizeof(JsonbInState));

  pushJsonbValue(&result, WJB_BEGIN_OBJECT, NULL);

  switch (ndims)
  {
    case 0:
      goto close_object;
      break;

    case 1:
      if ((ARR_DIMS(in_array)[0]) % 2)
        ereport(ERROR,
            (errcode(ERRCODE_ARRAY_SUBSCRIPT_ERROR),
             errmsg("array must have even number of elements")));
      break;

    case 2:
      if ((ARR_DIMS(in_array)[1]) != 2)
        ereport(ERROR,
            (errcode(ERRCODE_ARRAY_SUBSCRIPT_ERROR),
             errmsg("array must have two columns")));
      break;

    default:
      ereport(ERROR,
          (errcode(ERRCODE_ARRAY_SUBSCRIPT_ERROR),
           errmsg("wrong number of array subscripts")));
  }

  deconstruct_array_builtin(in_array, TEXTOID, &in_datums, &in_nulls, &in_count);

  count = in_count / 2;

  for (i = 0; i < count; ++i)
  {
    JsonbValue  v;
    char     *str;
    int     len;

    if (in_nulls[i * 2])
      ereport(ERROR,
          (errcode(ERRCODE_NULL_VALUE_NOT_ALLOWED),
           errmsg("null value not allowed for object key")));

    str = TextDatumGetCString(in_datums[i * 2]);
    len = strlen(str);

    v.type = jbvString;

    v.val.string.len = len;
    v.val.string.val = str;

    pushJsonbValue(&result, WJB_KEY, &v);

    if (in_nulls[i * 2 + 1])
    {
      v.type = jbvNull;
    }
    else
    {
      str = TextDatumGetCString(in_datums[i * 2 + 1]);
      len = strlen(str);

      v.type = jbvString;

      v.val.string.len = len;
      v.val.string.val = str;
    }

    pushJsonbValue(&result, WJB_VALUE, &v);
  }

  pfree(in_datums);
  pfree(in_nulls);

close_object:
  pushJsonbValue(&result, WJB_END_OBJECT, NULL);

  PG_RETURN_POINTER(JsonbValueToJsonb(result.result));
}

/*
 * SQL function jsonb_object(text[], text[])
 *
 * take separate name and value arrays of text to construct a jsonb object
 * pairwise.
 */
Datum
jsonb_object_two_arg(PG_FUNCTION_ARGS)
{
  ArrayType  *key_array = PG_GETARG_ARRAYTYPE_P(0);
  ArrayType  *val_array = PG_GETARG_ARRAYTYPE_P(1);
  int     nkdims = ARR_NDIM(key_array);
  int     nvdims = ARR_NDIM(val_array);
  Datum    *key_datums,
         *val_datums;
  bool     *key_nulls,
         *val_nulls;
  int     key_count,
        val_count,
        i;
  JsonbInState result;

  memset(&result, 0, sizeof(JsonbInState));

  pushJsonbValue(&result, WJB_BEGIN_OBJECT, NULL);

  if (nkdims > 1 || nkdims != nvdims)
    ereport(ERROR,
        (errcode(ERRCODE_ARRAY_SUBSCRIPT_ERROR),
         errmsg("wrong number of array subscripts")));

  if (nkdims == 0)
    goto close_object;

  deconstruct_array_builtin(key_array, TEXTOID, &key_datums, &key_nulls, &key_count);
  deconstruct_array_builtin(val_array, TEXTOID, &val_datums, &val_nulls, &val_count);

  if (key_count != val_count)
    ereport(ERROR,
        (errcode(ERRCODE_ARRAY_SUBSCRIPT_ERROR),
         errmsg("mismatched array dimensions")));

  for (i = 0; i < key_count; ++i)
  {
    JsonbValue  v;
    char     *str;
    int     len;

    if (key_nulls[i])
      ereport(ERROR,
          (errcode(ERRCODE_NULL_VALUE_NOT_ALLOWED),
           errmsg("null value not allowed for object key")));

    str = TextDatumGetCString(key_datums[i]);
    len = strlen(str);

    v.type = jbvString;

    v.val.string.len = len;
    v.val.string.val = str;

    pushJsonbValue(&result, WJB_KEY, &v);

    if (val_nulls[i])
    {
      v.type = jbvNull;
    }
    else
    {
      str = TextDatumGetCString(val_datums[i]);
      len = strlen(str);

      v.type = jbvString;

      v.val.string.len = len;
      v.val.string.val = str;
    }

    pushJsonbValue(&result, WJB_VALUE, &v);
  }

  pfree(key_datums);
  pfree(key_nulls);
  pfree(val_datums);
  pfree(val_nulls);

close_object:
  pushJsonbValue(&result, WJB_END_OBJECT, NULL);

  PG_RETURN_POINTER(JsonbValueToJsonb(result.result));
}


/*
 * Functions for jsonb_agg, jsonb_object_agg, and variants
 */

static Datum
jsonb_agg_transfn_worker(FunctionCallInfo fcinfo, bool absent_on_null)
{
  MemoryContext aggcontext;
  JsonbAggState *state;
  Datum   val;
  JsonbInState *result;

  if (!AggCheckCallContext(fcinfo, &aggcontext))
  {
    /* cannot be called directly because of internal-type argument */
    elog(ERROR, "jsonb_agg_transfn called in non-aggregate context");
  }

  /* set up the accumulator on the first go round */

  if (PG_ARGISNULL(0))
  {
    Oid     arg_type = get_fn_expr_argtype(fcinfo->flinfo, 1);

    if (arg_type == InvalidOid)
      ereport(ERROR,
          (errcode(ERRCODE_INVALID_PARAMETER_VALUE),
           errmsg("could not determine input data type")));

    state = MemoryContextAllocZero(aggcontext, sizeof(JsonbAggState));
    result = &state->pstate;
    result->outcontext = aggcontext;
    pushJsonbValue(result, WJB_BEGIN_ARRAY, NULL);

    json_categorize_type(arg_type, true, &state->val_category,
               &state->val_output_func);
  }
  else
  {
    state = (JsonbAggState *) PG_GETARG_POINTER(0);
    result = &state->pstate;
  }

  if (absent_on_null && PG_ARGISNULL(1))
    PG_RETURN_POINTER(state);

  /*
   * We run this code in the normal function context, so that we don't leak
   * any cruft from datatype output functions and such into the aggcontext.
   * But the "result" JsonbValue will be constructed in aggcontext, so that
   * it remains available across calls.
   */
  val = PG_ARGISNULL(1) ? (Datum) 0 : PG_GETARG_DATUM(1);

  datum_to_jsonb_internal(val, PG_ARGISNULL(1), result, state->val_category,
              state->val_output_func, false);

  PG_RETURN_POINTER(state);
}

/*
 * jsonb_agg aggregate function
 */
Datum
jsonb_agg_transfn(PG_FUNCTION_ARGS)
{
  return jsonb_agg_transfn_worker(fcinfo, false);
}

/*
 * jsonb_agg_strict aggregate function
 */
Datum
jsonb_agg_strict_transfn(PG_FUNCTION_ARGS)
{
  return jsonb_agg_transfn_worker(fcinfo, true);
}

Datum
jsonb_agg_finalfn(PG_FUNCTION_ARGS)
{
  JsonbAggState *arg;
  JsonbInState result;
  Jsonb    *out;

  /* cannot be called directly because of internal-type argument */
  Assert(AggCheckCallContext(fcinfo, NULL));

  if (PG_ARGISNULL(0))
    PG_RETURN_NULL();   /* returns null iff no input values */

  arg = (JsonbAggState *) PG_GETARG_POINTER(0);

  /*
   * The final function can be called more than once, so we must not change
   * the stored JsonbValue data structure.  Fortunately, the WJB_END_ARRAY
   * action will only change fields in the JsonbInState struct itself, so we
   * can simply invoke pushJsonbValue on a local copy of that.
   */
  result = arg->pstate;

  pushJsonbValue(&result, WJB_END_ARRAY, NULL);

  /* We expect result.parseState == NULL after closing the array */
  Assert(result.parseState == NULL);

  out = JsonbValueToJsonb(result.result);

  PG_RETURN_POINTER(out);
}

static Datum
jsonb_object_agg_transfn_worker(FunctionCallInfo fcinfo,
                bool absent_on_null, bool unique_keys)
{
  MemoryContext aggcontext;
  JsonbAggState *state;
  Datum   val;
  JsonbInState *result;
  bool    skip;

  if (!AggCheckCallContext(fcinfo, &aggcontext))
  {
    /* cannot be called directly because of internal-type argument */
    elog(ERROR, "jsonb_object_agg_transfn called in non-aggregate context");
  }

  /* set up the accumulator on the first go round */

  if (PG_ARGISNULL(0))
  {
    Oid     arg_type;

    state = MemoryContextAllocZero(aggcontext, sizeof(JsonbAggState));
    result = &state->pstate;
    result->outcontext = aggcontext;
    pushJsonbValue(result, WJB_BEGIN_OBJECT, NULL);
    result->parseState->unique_keys = unique_keys;
    result->parseState->skip_nulls = absent_on_null;

    arg_type = get_fn_expr_argtype(fcinfo->flinfo, 1);

    if (arg_type == InvalidOid)
      ereport(ERROR,
          (errcode(ERRCODE_INVALID_PARAMETER_VALUE),
           errmsg("could not determine input data type")));

    json_categorize_type(arg_type, true, &state->key_category,
               &state->key_output_func);

    arg_type = get_fn_expr_argtype(fcinfo->flinfo, 2);

    if (arg_type == InvalidOid)
      ereport(ERROR,
          (errcode(ERRCODE_INVALID_PARAMETER_VALUE),
           errmsg("could not determine input data type")));

    json_categorize_type(arg_type, true, &state->val_category,
               &state->val_output_func);
  }
  else
  {
    state = (JsonbAggState *) PG_GETARG_POINTER(0);
    result = &state->pstate;
  }

  if (PG_ARGISNULL(1))
    ereport(ERROR,
        (errcode(ERRCODE_INVALID_PARAMETER_VALUE),
         errmsg("field name must not be null")));

  /*
   * Skip null values if absent_on_null unless key uniqueness check is
   * needed (because we must save keys in this case).
   */
  skip = absent_on_null && PG_ARGISNULL(2);

  if (skip && !unique_keys)
    PG_RETURN_POINTER(state);

  /*
   * We run this code in the normal function context, so that we don't leak
   * any cruft from datatype output functions and such into the aggcontext.
   * But the "result" JsonbValue will be constructed in aggcontext, so that
   * it remains available across calls.
   */
  val = PG_GETARG_DATUM(1);

  datum_to_jsonb_internal(val, false, result, state->key_category,
              state->key_output_func, true);

  val = PG_ARGISNULL(2) ? (Datum) 0 : PG_GETARG_DATUM(2);

  datum_to_jsonb_internal(val, PG_ARGISNULL(2), result, state->val_category,
              state->val_output_func, false);

  PG_RETURN_POINTER(state);
}

/*
 * jsonb_object_agg aggregate function
 */
Datum
jsonb_object_agg_transfn(PG_FUNCTION_ARGS)
{
  return jsonb_object_agg_transfn_worker(fcinfo, false, false);
}


/*
 * jsonb_object_agg_strict aggregate function
 */
Datum
jsonb_object_agg_strict_transfn(PG_FUNCTION_ARGS)
{
  return jsonb_object_agg_transfn_worker(fcinfo, true, false);
}

/*
 * jsonb_object_agg_unique aggregate function
 */
Datum
jsonb_object_agg_unique_transfn(PG_FUNCTION_ARGS)
{
  return jsonb_object_agg_transfn_worker(fcinfo, false, true);
}

/*
 * jsonb_object_agg_unique_strict aggregate function
 */
Datum
jsonb_object_agg_unique_strict_transfn(PG_FUNCTION_ARGS)
{
  return jsonb_object_agg_transfn_worker(fcinfo, true, true);
}

Datum
jsonb_object_agg_finalfn(PG_FUNCTION_ARGS)
{
  JsonbAggState *arg;
  JsonbInState result;
  Jsonb    *out;

  /* cannot be called directly because of internal-type argument */
  Assert(AggCheckCallContext(fcinfo, NULL));

  if (PG_ARGISNULL(0))
    PG_RETURN_NULL();   /* returns null iff no input values */

  arg = (JsonbAggState *) PG_GETARG_POINTER(0);

  /*
   * The final function can be called more than once, so we must not change
   * the stored JsonbValue data structure.  Fortunately, the WJB_END_OBJECT
   * action will only destructively change fields in the JsonbInState struct
   * itself, so we can simply invoke pushJsonbValue on a local copy of that.
   * Note that this will run uniqueifyJsonbObject each time; that's hard to
   * avoid, since duplicate pairs may have been added since the previous
   * finalization.  We assume uniqueifyJsonbObject can be applied repeatedly
   * (with the same unique_keys/skip_nulls options) without damaging the
   * data structure.
   */
  result = arg->pstate;

  pushJsonbValue(&result, WJB_END_OBJECT, NULL);

  /* We expect result.parseState == NULL after closing the object */
  Assert(result.parseState == NULL);

  out = JsonbValueToJsonb(result.result);

  PG_RETURN_POINTER(out);
}


/*
 * Extract scalar value from raw-scalar pseudo-array jsonb.
 */
bool
JsonbExtractScalar(JsonbContainer *jbc, JsonbValue *res)
{
  JsonbIterator *it;
  JsonbIteratorToken tok PG_USED_FOR_ASSERTS_ONLY;
  JsonbValue  tmp;

  if (!JsonContainerIsArray(jbc) || !JsonContainerIsScalar(jbc))
  {
    /* inform caller about actual type of container */
    res->type = (JsonContainerIsArray(jbc)) ? jbvArray : jbvObject;
    return false;
  }

  /*
   * A root scalar is stored as an array of one element, so we get the array
   * and then its first (and only) member.
   */
  it = JsonbIteratorInit(jbc);

  tok = JsonbIteratorNext(&it, &tmp, true);
  Assert(tok == WJB_BEGIN_ARRAY);
  Assert(tmp.val.array.nElems == 1 && tmp.val.array.rawScalar);

  tok = JsonbIteratorNext(&it, res, true);
  Assert(tok == WJB_ELEM);
  Assert(IsAJsonbScalar(res));

  tok = JsonbIteratorNext(&it, &tmp, true);
  Assert(tok == WJB_END_ARRAY);

  tok = JsonbIteratorNext(&it, &tmp, true);
  Assert(tok == WJB_DONE);

  return true;
}

/*
 * Emit correct, translatable cast error message
 */
static Datum
cannotCastJsonbValue(enum jbvType type, const char *sqltype, Node *escontext)
{
  static const struct
  {
    enum jbvType type;
    const char *msg;
  }
        messages[] =
  {
    {jbvNull, gettext_noop("cannot cast jsonb null to type %s")},
    {jbvString, gettext_noop("cannot cast jsonb string to type %s")},
    {jbvNumeric, gettext_noop("cannot cast jsonb numeric to type %s")},
    {jbvBool, gettext_noop("cannot cast jsonb boolean to type %s")},
    {jbvArray, gettext_noop("cannot cast jsonb array to type %s")},
    {jbvObject, gettext_noop("cannot cast jsonb object to type %s")},
    {jbvBinary, gettext_noop("cannot cast jsonb array or object to type %s")}
  };

  for (size_t i = 0; i < lengthof(messages); i++)
    if (messages[i].type == type)
      ereturn(escontext, (Datum) 0,
          (errcode(ERRCODE_INVALID_PARAMETER_VALUE),
           errmsg(messages[i].msg, sqltype)));

  /* should be unreachable */
  elog(ERROR, "unknown jsonb type: %d", (int) type);
  return (Datum) 0;
}

Datum
jsonb_bool(PG_FUNCTION_ARGS)
{
  Jsonb    *in = PG_GETARG_JSONB_P(0);
  JsonbValue  v;

  if (!JsonbExtractScalar(&in->root, &v))
    return cannotCastJsonbValue(v.type, "boolean", fcinfo->context);

  if (v.type == jbvNull)
  {
    PG_FREE_IF_COPY(in, 0);
    PG_RETURN_NULL();
  }

  if (v.type != jbvBool)
    return cannotCastJsonbValue(v.type, "boolean", fcinfo->context);

  PG_FREE_IF_COPY(in, 0);

  PG_RETURN_BOOL(v.val.boolean);
}

Datum
jsonb_numeric(PG_FUNCTION_ARGS)
{
  Jsonb    *in = PG_GETARG_JSONB_P(0);
  JsonbValue  v;
  Numeric   retValue;

  if (!JsonbExtractScalar(&in->root, &v))
    return cannotCastJsonbValue(v.type, "numeric", fcinfo->context);

  if (v.type == jbvNull)
  {
    PG_FREE_IF_COPY(in, 0);
    PG_RETURN_NULL();
  }

  if (v.type != jbvNumeric)
    return cannotCastJsonbValue(v.type, "numeric", fcinfo->context);

  /*
   * v.val.numeric points into jsonb body, so we need to make a copy to
   * return
   */
  retValue = DatumGetNumericCopy(NumericGetDatum(v.val.numeric));

  PG_FREE_IF_COPY(in, 0);

  PG_RETURN_NUMERIC(retValue);
}

Datum
jsonb_int2(PG_FUNCTION_ARGS)
{
  Jsonb    *in = PG_GETARG_JSONB_P(0);
  JsonbValue  v;
  Datum   retValue;

  if (!JsonbExtractScalar(&in->root, &v))
    return cannotCastJsonbValue(v.type, "smallint", fcinfo->context);

  if (v.type == jbvNull)
  {
    PG_FREE_IF_COPY(in, 0);
    PG_RETURN_NULL();
  }

  if (v.type != jbvNumeric)
    return cannotCastJsonbValue(v.type, "smallint", fcinfo->context);

  retValue = DirectFunctionCall1(numeric_int2,
                   NumericGetDatum(v.val.numeric));

  PG_FREE_IF_COPY(in, 0);

  PG_RETURN_DATUM(retValue);
}

Datum
jsonb_int4(PG_FUNCTION_ARGS)
{
  Jsonb    *in = PG_GETARG_JSONB_P(0);
  JsonbValue  v;
  Datum   retValue;

  if (!JsonbExtractScalar(&in->root, &v))
    return cannotCastJsonbValue(v.type, "integer", fcinfo->context);

  if (v.type == jbvNull)
  {
    PG_FREE_IF_COPY(in, 0);
    PG_RETURN_NULL();
  }

  if (v.type != jbvNumeric)
    return cannotCastJsonbValue(v.type, "integer", fcinfo->context);

  retValue = DirectFunctionCall1(numeric_int4,
                   NumericGetDatum(v.val.numeric));

  PG_FREE_IF_COPY(in, 0);

  PG_RETURN_DATUM(retValue);
}

Datum
jsonb_int8(PG_FUNCTION_ARGS)
{
  Jsonb    *in = PG_GETARG_JSONB_P(0);
  JsonbValue  v;
  Datum   retValue;

  if (!JsonbExtractScalar(&in->root, &v))
    return cannotCastJsonbValue(v.type, "bigint", fcinfo->context);

  if (v.type == jbvNull)
  {
    PG_FREE_IF_COPY(in, 0);
    PG_RETURN_NULL();
  }

  if (v.type != jbvNumeric)
    return cannotCastJsonbValue(v.type, "bigint", fcinfo->context);

  retValue = DirectFunctionCall1(numeric_int8,
                   NumericGetDatum(v.val.numeric));

  PG_FREE_IF_COPY(in, 0);

  PG_RETURN_DATUM(retValue);
}

Datum
jsonb_float4(PG_FUNCTION_ARGS)
{
  Jsonb    *in = PG_GETARG_JSONB_P(0);
  JsonbValue  v;
  Datum   retValue;

  if (!JsonbExtractScalar(&in->root, &v))
    return cannotCastJsonbValue(v.type, "real", fcinfo->context);

  if (v.type == jbvNull)
  {
    PG_FREE_IF_COPY(in, 0);
    PG_RETURN_NULL();
  }

  if (v.type != jbvNumeric)
    return cannotCastJsonbValue(v.type, "real", fcinfo->context);

  retValue = DirectFunctionCall1(numeric_float4,
                   NumericGetDatum(v.val.numeric));

  PG_FREE_IF_COPY(in, 0);

  PG_RETURN_DATUM(retValue);
}

Datum
jsonb_float8(PG_FUNCTION_ARGS)
{
  Jsonb    *in = PG_GETARG_JSONB_P(0);
  JsonbValue  v;
  Datum   retValue;

  if (!JsonbExtractScalar(&in->root, &v))
    return cannotCastJsonbValue(v.type, "double precision", fcinfo->context);

  if (v.type == jbvNull)
  {
    PG_FREE_IF_COPY(in, 0);
    PG_RETURN_NULL();
  }

  if (v.type != jbvNumeric)
    return cannotCastJsonbValue(v.type, "double precision", fcinfo->context);

  retValue = DirectFunctionCall1(numeric_float8,
                   NumericGetDatum(v.val.numeric));

  PG_FREE_IF_COPY(in, 0);

  PG_RETURN_DATUM(retValue);
}

/*
 * Convert jsonb to a C-string stripping quotes from scalar strings.
 */
char *
JsonbUnquote(Jsonb *jb)
{
  if (JB_ROOT_IS_SCALAR(jb))
  {
    JsonbValue  v;

    (void) JsonbExtractScalar(&jb->root, &v);

    if (v.type == jbvString)
      return pnstrdup(v.val.string.val, v.val.string.len);
    else if (v.type == jbvBool)
      return pstrdup(v.val.boolean ? "true" : "false");
    else if (v.type == jbvNumeric)
      return DatumGetCString(DirectFunctionCall1(numeric_out,
                             PointerGetDatum(v.val.numeric)));
    else if (v.type == jbvNull)
      return pstrdup("null");
    else
    {
      elog(ERROR, "unrecognized jsonb value type %d", v.type);
      return NULL;
    }
  }
  else
    return JsonbToCString(NULL, &jb->root, VARSIZE(jb));
}

Coverage Report

Created: 2026-09-28 06:55