/*
* SQL function to_json(anyvalue)
*/
Datum
to_json(PG_FUNCTION_ARGS)
{
Datum val = PG_GETARG_DATUM(0);
Oid val_type = get_fn_expr_argtype(fcinfo->flinfo, 0);
StringInfo result;
TYPCATEGORY tcategory;
Oid typoutput;
bool typisvarlena;
Oid castfunc = InvalidOid;
if (val_type == InvalidOid)
ereport(ERROR,
(errcode(ERRCODE_INVALID_PARAMETER_VALUE),
errmsg("could not determine input data type")));
result = makeStringInfo();
getTypeOutputInfo(val_type, &typoutput, &typisvarlena);
if (val_type > FirstNormalObjectId)
{
HeapTuple tuple;
Form_pg_cast castForm;
tuple = SearchSysCache2(CASTSOURCETARGET,
ObjectIdGetDatum(val_type),
ObjectIdGetDatum(JSONOID));
if (HeapTupleIsValid(tuple))
{
castForm = (Form_pg_cast) GETSTRUCT(tuple);
if (castForm->castmethod == COERCION_METHOD_FUNCTION)
castfunc = typoutput = castForm->castfunc;
ReleaseSysCache(tuple);
}
}
if (castfunc != InvalidOid)
tcategory = TYPCATEGORY_JSON_CAST;
else if (val_type == RECORDARRAYOID)
tcategory = TYPCATEGORY_ARRAY;
else if (val_type == RECORDOID)
tcategory = TYPCATEGORY_COMPOSITE;
else if (val_type == JSONOID)
tcategory = TYPCATEGORY_JSON;
else
tcategory = TypeCategory(val_type);
datum_to_json(val, false, result, tcategory, typoutput);
PG_RETURN_TEXT_P(cstring_to_text(result->data));
}
/*
* 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_json(StringInfo result, int dim, int ndims,int * dims, Datum *vals,
bool *nulls, int * valcount, TYPCATEGORY tcategory,
Oid typoutputfunc, bool use_line_feeds)
{
int i;
char *sep;
Assert(dim < ndims);
sep = use_line_feeds ? ",\n " : ",";
appendStringInfoChar(result, '[');
for (i = 1; i <= dims[dim]; i++)
{
if (i > 1)
appendStringInfoString(result,sep);
if (dim + 1 == ndims)
{
datum_to_json(vals[*valcount], nulls[*valcount], result, tcategory,
typoutputfunc);
(*valcount)++;
}
else
{
/*
* Do we want line feeds on inner dimensions of arrays?
* For now we'll say no.
*/
array_dim_to_json(result, dim+1, ndims, dims, vals, nulls,
valcount, tcategory, typoutputfunc, false);
}
}
appendStringInfoChar(result, ']');
}
/*
* Turn a composite / record into JSON.
*/
static void
composite_to_json(Datum composite, StringInfo result, bool use_line_feeds)
{
HeapTupleHeader td;
Oid tupType;
int32 tupTypmod;
TupleDesc tupdesc;
HeapTupleData tmptup, *tuple;
int i;
bool needsep = false;
char *sep;
sep = use_line_feeds ? ",\n " : ",";
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, origval;
bool isnull;
char *attname;
TYPCATEGORY tcategory;
Oid typoutput;
bool typisvarlena;
if (tupdesc->attrs[i]->attisdropped)
continue;
if (needsep)
appendStringInfoString(result,sep);
needsep = true;
attname = NameStr(tupdesc->attrs[i]->attname);
escape_json(result,attname);
appendStringInfoChar(result,':');
origval = heap_getattr(tuple, i + 1, tupdesc, &isnull);
if (tupdesc->attrs[i]->atttypid == RECORDARRAYOID)
tcategory = TYPCATEGORY_ARRAY;
else if (tupdesc->attrs[i]->atttypid == RECORDOID)
tcategory = TYPCATEGORY_COMPOSITE;
else if (tupdesc->attrs[i]->atttypid == JSONOID)
tcategory = TYPCATEGORY_JSON;
else
tcategory = TypeCategory(tupdesc->attrs[i]->atttypid);
getTypeOutputInfo(tupdesc->attrs[i]->atttypid,
&typoutput, &typisvarlena);
/*
* If we have a toasted datum, forcibly detoast it here to avoid memory
* leakage inside the type's output routine.
*/
if (typisvarlena && ! isnull)
val = PointerGetDatum(PG_DETOAST_DATUM(origval));
else
val = origval;
datum_to_json(val, result, tcategory, typoutput);
/* Clean up detoasted copy, if any */
if (val != origval)
pfree(DatumGetPointer(val));
}
appendStringInfoChar(result,'}');
ReleaseTupleDesc(tupdesc);
}
/*
* json_agg transition function
*/
Datum
json_agg_transfn(PG_FUNCTION_ARGS)
{
Oid val_type = get_fn_expr_argtype(fcinfo->flinfo, 1);
MemoryContext aggcontext,
oldcontext;
StringInfo state;
Datum val;
TYPCATEGORY tcategory;
Oid typoutput;
bool typisvarlena;
Oid castfunc = InvalidOid;
if (val_type == InvalidOid)
ereport(ERROR,
(errcode(ERRCODE_INVALID_PARAMETER_VALUE),
errmsg("could not determine input data type")));
if (!AggCheckCallContext(fcinfo, &aggcontext))
{
/* cannot be called directly because of internal-type argument */
elog(ERROR, "json_agg_transfn called in non-aggregate context");
}
if (PG_ARGISNULL(0))
{
/*
* Make this StringInfo in a context where it will persist for the
* duration off the aggregate call. It's only needed for this initial
* piece, as the StringInfo routines make sure they use the right
* context to enlarge the object if necessary.
*/
oldcontext = MemoryContextSwitchTo(aggcontext);
state = makeStringInfo();
MemoryContextSwitchTo(oldcontext);
appendStringInfoChar(state, '[');
}
else
{
state = (StringInfo) PG_GETARG_POINTER(0);
appendStringInfoString(state, ", ");
}
/* fast path for NULLs */
if (PG_ARGISNULL(1))
{
val = (Datum) 0;
datum_to_json(val, true, state, 0, InvalidOid);
PG_RETURN_POINTER(state);
}
val = PG_GETARG_DATUM(1);
getTypeOutputInfo(val_type, &typoutput, &typisvarlena);
if (val_type > FirstNormalObjectId)
{
HeapTuple tuple;
Form_pg_cast castForm;
tuple = SearchSysCache2(CASTSOURCETARGET,
ObjectIdGetDatum(val_type),
ObjectIdGetDatum(JSONOID));
if (HeapTupleIsValid(tuple))
{
castForm = (Form_pg_cast) GETSTRUCT(tuple);
if (castForm->castmethod == COERCION_METHOD_FUNCTION)
castfunc = typoutput = castForm->castfunc;
ReleaseSysCache(tuple);
}
}
if (castfunc != InvalidOid)
tcategory = TYPCATEGORY_JSON_CAST;
else if (val_type == RECORDARRAYOID)
tcategory = TYPCATEGORY_ARRAY;
else if (val_type == RECORDOID)
tcategory = TYPCATEGORY_COMPOSITE;
else if (val_type == JSONOID)
tcategory = TYPCATEGORY_JSON;
else
tcategory = TypeCategory(val_type);
if (!PG_ARGISNULL(0) &&
(tcategory == TYPCATEGORY_ARRAY || tcategory == TYPCATEGORY_COMPOSITE))
{
appendStringInfoString(state, "\n ");
}
datum_to_json(val, false, state, tcategory, typoutput);
/*
* The transition type for array_agg() is declared to be "internal", which
* is a pass-by-value type the same size as a pointer. So we can safely
* pass the ArrayBuildState pointer through nodeAgg.c's machinations.
*/
PG_RETURN_POINTER(state);
}
/*
* Turn a composite / record into JSON.
*/
static void
composite_to_json(Datum composite, StringInfo result, bool use_line_feeds)
{
HeapTupleHeader td;
Oid tupType;
int32 tupTypmod;
TupleDesc tupdesc;
HeapTupleData tmptup,
*tuple;
int i;
bool needsep = false;
const char *sep;
sep = use_line_feeds ? ",\n " : ",";
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;
TYPCATEGORY tcategory;
Oid typoutput;
bool typisvarlena;
Oid castfunc = InvalidOid;
if (tupdesc->attrs[i]->attisdropped)
continue;
if (needsep)
appendStringInfoString(result, sep);
needsep = true;
attname = NameStr(tupdesc->attrs[i]->attname);
escape_json(result, attname);
appendStringInfoChar(result, ':');
val = heap_getattr(tuple, i + 1, tupdesc, &isnull);
getTypeOutputInfo(tupdesc->attrs[i]->atttypid,
&typoutput, &typisvarlena);
if (tupdesc->attrs[i]->atttypid > FirstNormalObjectId)
{
HeapTuple cast_tuple;
Form_pg_cast castForm;
cast_tuple = SearchSysCache2(CASTSOURCETARGET,
ObjectIdGetDatum(tupdesc->attrs[i]->atttypid),
ObjectIdGetDatum(JSONOID));
if (HeapTupleIsValid(cast_tuple))
{
castForm = (Form_pg_cast) GETSTRUCT(cast_tuple);
if (castForm->castmethod == COERCION_METHOD_FUNCTION)
castfunc = typoutput = castForm->castfunc;
ReleaseSysCache(cast_tuple);
}
}
if (castfunc != InvalidOid)
tcategory = TYPCATEGORY_JSON_CAST;
else if (tupdesc->attrs[i]->atttypid == RECORDARRAYOID)
tcategory = TYPCATEGORY_ARRAY;
else if (tupdesc->attrs[i]->atttypid == RECORDOID)
tcategory = TYPCATEGORY_COMPOSITE;
else if (tupdesc->attrs[i]->atttypid == JSONOID)
tcategory = TYPCATEGORY_JSON;
else
tcategory = TypeCategory(tupdesc->attrs[i]->atttypid);
datum_to_json(val, isnull, result, tcategory, typoutput);
}
appendStringInfoChar(result, '}');
ReleaseTupleDesc(tupdesc);
}
/*
* SQL function to_json(anyvalue)
*/
Datum
to_json(PG_FUNCTION_ARGS)
{
Oid val_type = get_fn_expr_argtype(fcinfo->flinfo, 0);
StringInfo result;
Datum orig_val,
val;
TYPCATEGORY tcategory;
Oid typoutput;
bool typisvarlena;
Oid castfunc = InvalidOid;
if (val_type == InvalidOid)
ereport(ERROR,
(errcode(ERRCODE_INVALID_PARAMETER_VALUE),
errmsg("could not determine input data type")));
result = makeStringInfo();
orig_val = PG_ARGISNULL(0) ? (Datum) 0 : PG_GETARG_DATUM(0);
getTypeOutputInfo(val_type, &typoutput, &typisvarlena);
if (val_type > FirstNormalObjectId)
{
HeapTuple tuple;
Form_pg_cast castForm;
tuple = SearchSysCache2(CASTSOURCETARGET,
ObjectIdGetDatum(val_type),
ObjectIdGetDatum(JSONOID));
if (HeapTupleIsValid(tuple))
{
castForm = (Form_pg_cast) GETSTRUCT(tuple);
if (castForm->castmethod == COERCION_METHOD_FUNCTION)
castfunc = typoutput = castForm->castfunc;
ReleaseSysCache(tuple);
}
}
if (castfunc != InvalidOid)
tcategory = TYPCATEGORY_JSON_CAST;
else if (val_type == RECORDARRAYOID)
tcategory = TYPCATEGORY_ARRAY;
else if (val_type == RECORDOID)
tcategory = TYPCATEGORY_COMPOSITE;
else if (val_type == JSONOID)
tcategory = TYPCATEGORY_JSON;
else
tcategory = TypeCategory(val_type);
/*
* If we have a toasted datum, forcibly detoast it here to avoid memory
* leakage inside the type's output routine.
*/
if (typisvarlena && orig_val != (Datum) 0)
val = PointerGetDatum(PG_DETOAST_DATUM(orig_val));
else
val = orig_val;
datum_to_json(val, false, result, tcategory, typoutput);
/* Clean up detoasted copy, if any */
if (val != orig_val)
pfree(DatumGetPointer(val));
PG_RETURN_TEXT_P(cstring_to_text(result->data));
}
