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mirror of https://github.com/postgres/postgres.git synced 2025-11-19 13:42:17 +03:00

SQL/JSON constructors

This patch introduces the SQL/JSON standard constructors for JSON:

JSON()
JSON_ARRAY()
JSON_ARRAYAGG()
JSON_OBJECT()
JSON_OBJECTAGG()

For the most part these functions provide facilities that mimic
existing json/jsonb functions. However, they also offer some useful
additional functionality. In addition to text input, the JSON() function
accepts bytea input, which it will decode and constuct a json value from.
The other functions provide useful options for handling duplicate keys
and null values.

This series of patches will be followed by a consolidated documentation
patch.

Nikita Glukhov

Reviewers have included (in no particular order) Andres Freund, Alexander
Korotkov, Pavel Stehule, Andrew Alsup, Erik Rijkers, Zihong Yu,
Himanshu Upadhyaya, Daniel Gustafsson, Justin Pryzby.

Discussion: https://postgr.es/m/cd0bb935-0158-78a7-08b5-904886deac4b@postgrespro.ru
This commit is contained in:
Andrew Dunstan
2022-03-03 13:02:10 -05:00
parent f79b803dcc
commit f4fb45d15c
37 changed files with 3615 additions and 130 deletions

View File

@@ -14,6 +14,7 @@
#include "access/htup_details.h"
#include "access/transam.h"
#include "catalog/pg_proc.h"
#include "catalog/pg_type.h"
#include "funcapi.h"
#include "libpq/pqformat.h"
@@ -1126,6 +1127,39 @@ add_jsonb(Datum val, bool is_null, JsonbInState *result,
datum_to_jsonb(val, is_null, result, tcategory, outfuncoid, key_scalar);
}
bool
to_jsonb_is_immutable(Oid typoid)
{
JsonbTypeCategory tcategory;
Oid outfuncoid;
jsonb_categorize_type(typoid, &tcategory, &outfuncoid);
switch (tcategory)
{
case JSONBTYPE_BOOL:
case JSONBTYPE_JSON:
case JSONBTYPE_JSONB:
return true;
case JSONBTYPE_DATE:
case JSONBTYPE_TIMESTAMP:
case JSONBTYPE_TIMESTAMPTZ:
return false;
case JSONBTYPE_ARRAY:
return false; /* TODO recurse into elements */
case JSONBTYPE_COMPOSITE:
return false; /* TODO recurse into fields */
case JSONBTYPE_NUMERIC:
case JSONBTYPE_JSONCAST:
default:
return func_volatile(outfuncoid) == PROVOLATILE_IMMUTABLE;
}
}
/*
* SQL function to_jsonb(anyvalue)
*/
@@ -1153,24 +1187,12 @@ to_jsonb(PG_FUNCTION_ARGS)
PG_RETURN_POINTER(JsonbValueToJsonb(result.res));
}
/*
* SQL function jsonb_build_object(variadic "any")
*/
Datum
jsonb_build_object(PG_FUNCTION_ARGS)
jsonb_build_object_worker(int nargs, Datum *args, bool *nulls, Oid *types,
bool absent_on_null, bool unique_keys)
{
int nargs;
int i;
JsonbInState result;
Datum *args;
bool *nulls;
Oid *types;
/* build argument values to build the object */
nargs = extract_variadic_args(fcinfo, 0, true, &args, &types, &nulls);
if (nargs < 0)
PG_RETURN_NULL();
if (nargs % 2 != 0)
ereport(ERROR,
@@ -1183,15 +1205,26 @@ jsonb_build_object(PG_FUNCTION_ARGS)
memset(&result, 0, sizeof(JsonbInState));
result.res = pushJsonbValue(&result.parseState, 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 */
@@ -1200,7 +1233,26 @@ jsonb_build_object(PG_FUNCTION_ARGS)
result.res = pushJsonbValue(&result.parseState, WJB_END_OBJECT, NULL);
PG_RETURN_POINTER(JsonbValueToJsonb(result.res));
return JsonbPGetDatum(JsonbValueToJsonb(result.res));
}
/*
* 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));
}
/*
@@ -1219,37 +1271,50 @@ jsonb_build_object_noargs(PG_FUNCTION_ARGS)
PG_RETURN_POINTER(JsonbValueToJsonb(result.res));
}
/*
* SQL function jsonb_build_array(variadic "any")
*/
Datum
jsonb_build_array(PG_FUNCTION_ARGS)
jsonb_build_array_worker(int nargs, Datum *args, bool *nulls, Oid *types,
bool absent_on_null)
{
int nargs;
int i;
JsonbInState result;
Datum *args;
bool *nulls;
Oid *types;
/* build argument values to build the array */
nargs = extract_variadic_args(fcinfo, 0, true, &args, &types, &nulls);
if (nargs < 0)
PG_RETURN_NULL();
memset(&result, 0, sizeof(JsonbInState));
result.res = pushJsonbValue(&result.parseState, 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);
}
result.res = pushJsonbValue(&result.parseState, WJB_END_ARRAY, NULL);
PG_RETURN_POINTER(JsonbValueToJsonb(result.res));
return JsonbPGetDatum(JsonbValueToJsonb(result.res));
}
/*
* 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.
*/
@@ -1490,6 +1555,8 @@ clone_parse_state(JsonbParseState *state)
{
ocursor->contVal = icursor->contVal;
ocursor->size = icursor->size;
ocursor->unique_keys = icursor->unique_keys;
ocursor->skip_nulls = icursor->skip_nulls;
icursor = icursor->next;
if (icursor == NULL)
break;
@@ -1501,12 +1568,8 @@ clone_parse_state(JsonbParseState *state)
return result;
}
/*
* jsonb_agg aggregate function
*/
Datum
jsonb_agg_transfn(PG_FUNCTION_ARGS)
static Datum
jsonb_agg_transfn_worker(FunctionCallInfo fcinfo, bool absent_on_null)
{
MemoryContext oldcontext,
aggcontext;
@@ -1554,6 +1617,9 @@ jsonb_agg_transfn(PG_FUNCTION_ARGS)
result = state->res;
}
if (absent_on_null && PG_ARGISNULL(1))
PG_RETURN_POINTER(state);
/* turn the argument into jsonb in the normal function context */
val = PG_ARGISNULL(1) ? (Datum) 0 : PG_GETARG_DATUM(1);
@@ -1623,6 +1689,24 @@ jsonb_agg_transfn(PG_FUNCTION_ARGS)
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)
{
@@ -1655,11 +1739,9 @@ jsonb_agg_finalfn(PG_FUNCTION_ARGS)
PG_RETURN_POINTER(out);
}
/*
* jsonb_object_agg aggregate function
*/
Datum
jsonb_object_agg_transfn(PG_FUNCTION_ARGS)
static Datum
jsonb_object_agg_transfn_worker(FunctionCallInfo fcinfo,
bool absent_on_null, bool unique_keys)
{
MemoryContext oldcontext,
aggcontext;
@@ -1673,6 +1755,7 @@ jsonb_object_agg_transfn(PG_FUNCTION_ARGS)
*jbval;
JsonbValue v;
JsonbIteratorToken type;
bool skip;
if (!AggCheckCallContext(fcinfo, &aggcontext))
{
@@ -1692,6 +1775,9 @@ jsonb_object_agg_transfn(PG_FUNCTION_ARGS)
state->res = result;
result->res = pushJsonbValue(&result->parseState,
WJB_BEGIN_OBJECT, NULL);
result->parseState->unique_keys = unique_keys;
result->parseState->skip_nulls = absent_on_null;
MemoryContextSwitchTo(oldcontext);
arg_type = get_fn_expr_argtype(fcinfo->flinfo, 1);
@@ -1727,6 +1813,15 @@ jsonb_object_agg_transfn(PG_FUNCTION_ARGS)
(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);
val = PG_GETARG_DATUM(1);
memset(&elem, 0, sizeof(JsonbInState));
@@ -1782,6 +1877,16 @@ jsonb_object_agg_transfn(PG_FUNCTION_ARGS)
}
result->res = pushJsonbValue(&result->parseState,
WJB_KEY, &v);
if (skip)
{
v.type = jbvNull;
result->res = pushJsonbValue(&result->parseState,
WJB_VALUE, &v);
MemoryContextSwitchTo(oldcontext);
PG_RETURN_POINTER(state);
}
break;
case WJB_END_ARRAY:
break;
@@ -1854,6 +1959,43 @@ jsonb_object_agg_transfn(PG_FUNCTION_ARGS)
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)
{