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Postgres FD Implementation
Commit 0ca6bda8 authored by Tom Lane's avatar Tom Lane
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Get rid of bogus dependency on typcategory in to_json() and friends. 

These functions were relying on typcategory to identify arrays and
composites, which is not reliable and not the normal way to do it.
Using typcategory to identify boolean, numeric types, and json itself is
also pretty questionable, though the code in those cases didn't seem to be
at risk of anything worse than wrong output.  Instead, use the standard
lsyscache functions to identify arrays and composites, and rely on a direct
check of the type OID for the other cases.

In HEAD, also be sure to look through domains so that a domain is treated
the same as its base type for conversions to JSON.  However, this is a
small behavioral change; given the lack of field complaints, we won't
back-patch it.

In passing, refactor so that there's only one copy of the code that decides
which conversion strategy to apply, not multiple copies that could (and
have) gotten out of sync.
parent f1d8dd36
Hide whitespace changes
Inline Side-by-side
Showing with 181 additions and 229 deletions
src/backend/utils/adt/json.c
View file @ 0ca6bda8
......@@ -48,6 +48,18 @@ typedef enum /* contexts of JSON parser */
JSON_PARSE_END /* saw the end of a document, expect nothing */
} JsonParseContext;
typedef enum /* type categories for datum_to_json */
{
JSONTYPE_NULL, /* null, so we didn't bother to identify */
JSONTYPE_BOOL, /* boolean (built-in types only) */
JSONTYPE_NUMERIC, /* numeric (ditto) */
JSONTYPE_JSON, /* JSON itself (and JSONB) */
JSONTYPE_ARRAY, /* array */
JSONTYPE_COMPOSITE, /* composite */
JSONTYPE_CAST, /* something with an explicit cast to JSON */
JSONTYPE_OTHER /* all else */
} JsonTypeCategory;
static inline void json_lex(JsonLexContext *lex);
static inline void json_lex_string(JsonLexContext *lex);
static inline void json_lex_number(JsonLexContext *lex, char *s, bool *num_err);
......@@ -64,12 +76,16 @@ static void composite_to_json(Datum composite, StringInfo result,
bool use_line_feeds);
static void array_dim_to_json(StringInfo result, int dim, int ndims, int *dims,
Datum *vals, bool *nulls, int *valcount,
TYPCATEGORY tcategory, Oid typoutputfunc,
JsonTypeCategory tcategory, Oid outfuncoid,
bool use_line_feeds);
static void array_to_json_internal(Datum array, StringInfo result,
bool use_line_feeds);
static void json_categorize_type(Oid typoid,
JsonTypeCategory *tcategory,
Oid *outfuncoid);
static void datum_to_json(Datum val, bool is_null, StringInfo result,
TYPCATEGORY tcategory, Oid typoutputfunc, bool key_scalar);
JsonTypeCategory tcategory, Oid outfuncoid,
bool key_scalar);
static void add_json(Datum val, bool is_null, StringInfo result,
Oid val_type, bool key_scalar);
......@@ -143,14 +159,6 @@ lex_expect(JsonParseContext ctx, JsonLexContext *lex, JsonTokenType token)
report_parse_error(ctx, lex);;
}
/*
* All the defined type categories are upper case , so use lower case here
* so we avoid any possible clash.
*/
/* fake type category for JSON so we can distinguish it in datum_to_json */
#define TYPCATEGORY_JSON 'j'
/* fake category for types that have a cast to json */
#define TYPCATEGORY_JSON_CAST 'c'
/* chars to consider as part of an alphanumeric token */
#define JSON_ALPHANUMERIC_CHAR(c) \
(((c) >= 'a' && (c) <= 'z') || \
......@@ -1219,14 +1227,95 @@ extract_mb_char(char *s)
}
/*
* Turn a scalar Datum into JSON, appending the string to "result".
* Determine how we want to print values of a given type in datum_to_json.
*
* Hand off a non-scalar datum to composite_to_json or array_to_json_internal
* as appropriate.
* Given the datatype OID, return its JsonTypeCategory, as well as the type's
* output function OID. If the returned category is JSONTYPE_CAST, we
* return the OID of the type->JSON cast function instead.
*/
static void
json_categorize_type(Oid typoid,
JsonTypeCategory *tcategory,
Oid *outfuncoid)
{
bool typisvarlena;
/* Look through any domain */
typoid = getBaseType(typoid);
/* We'll usually need to return the type output function */
getTypeOutputInfo(typoid, outfuncoid, &typisvarlena);
/* Check for known types */
switch (typoid)
{
case BOOLOID:
*tcategory = JSONTYPE_BOOL;
break;
case INT2OID:
case INT4OID:
case INT8OID:
case FLOAT4OID:
case FLOAT8OID:
case NUMERICOID:
*tcategory = JSONTYPE_NUMERIC;
break;
case JSONOID:
case JSONBOID:
*tcategory = JSONTYPE_JSON;
break;
default:
/* Check for arrays and composites */
if (OidIsValid(get_element_type(typoid)))
*tcategory = JSONTYPE_ARRAY;
else if (type_is_rowtype(typoid))
*tcategory = JSONTYPE_COMPOSITE;
else
{
/* It's probably the general case ... */
*tcategory = JSONTYPE_OTHER;
/* but let's look for a cast to json, if it's not built-in */
if (typoid >= FirstNormalObjectId)
{
HeapTuple tuple;
tuple = SearchSysCache2(CASTSOURCETARGET,
ObjectIdGetDatum(typoid),
ObjectIdGetDatum(JSONOID));
if (HeapTupleIsValid(tuple))
{
Form_pg_cast castForm = (Form_pg_cast) GETSTRUCT(tuple);
if (castForm->castmethod == COERCION_METHOD_FUNCTION)
{
*tcategory = JSONTYPE_CAST;
*outfuncoid = castForm->castfunc;
}
ReleaseSysCache(tuple);
}
}
}
break;
}
}
/*
* Turn a Datum into JSON text, appending the string to "result".
*
* 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 being printed as a key, so insist
* it's of an acceptable type, and force it to be quoted.
*/
static void
datum_to_json(Datum val, bool is_null, StringInfo result,
TYPCATEGORY tcategory, Oid typoutputfunc, bool key_scalar)
JsonTypeCategory tcategory, Oid outfuncoid,
bool key_scalar)
{
char *outputstr;
text *jsontext;
......@@ -1239,22 +1328,32 @@ datum_to_json(Datum val, bool is_null, StringInfo result,
return;
}
if (key_scalar &&
(tcategory == JSONTYPE_ARRAY ||
tcategory == JSONTYPE_COMPOSITE ||
tcategory == JSONTYPE_JSON ||
tcategory == JSONTYPE_CAST))
ereport(ERROR,
(errcode(ERRCODE_INVALID_PARAMETER_VALUE),
errmsg("key value must be scalar, not array, composite or json")));
switch (tcategory)
{
case TYPCATEGORY_ARRAY:
case JSONTYPE_ARRAY:
array_to_json_internal(val, result, false);
break;
case TYPCATEGORY_COMPOSITE:
case JSONTYPE_COMPOSITE:
composite_to_json(val, result, false);
break;
case TYPCATEGORY_BOOLEAN:
if (!key_scalar)
appendStringInfoString(result, DatumGetBool(val) ? "true" : "false");
case JSONTYPE_BOOL:
outputstr = DatumGetBool(val) ? "true" : "false";
if (key_scalar)
escape_json(result, outputstr);
else
escape_json(result, DatumGetBool(val) ? "true" : "false");
appendStringInfoString(result, outputstr);
break;
case TYPCATEGORY_NUMERIC:
outputstr = OidOutputFunctionCall(typoutputfunc, val);
case JSONTYPE_NUMERIC:
outputstr = OidOutputFunctionCall(outfuncoid, val);
if (key_scalar)
{
/* always quote keys */
......@@ -1276,21 +1375,22 @@ datum_to_json(Datum val, bool is_null, StringInfo result,
}
pfree(outputstr);
break;
case TYPCATEGORY_JSON:
/* JSON and JSONB will already be escaped */
outputstr = OidOutputFunctionCall(typoutputfunc, val);
case JSONTYPE_JSON:
/* JSON and JSONB output will already be escaped */
outputstr = OidOutputFunctionCall(outfuncoid, val);
appendStringInfoString(result, outputstr);
pfree(outputstr);
break;
case TYPCATEGORY_JSON_CAST:
jsontext = DatumGetTextP(OidFunctionCall1(typoutputfunc, val));
case JSONTYPE_CAST:
/* outfuncoid refers to a cast function, not an output function */
jsontext = DatumGetTextP(OidFunctionCall1(outfuncoid, val));
outputstr = text_to_cstring(jsontext);
appendStringInfoString(result, outputstr);
pfree(outputstr);
pfree(jsontext);
break;
default:
outputstr = OidOutputFunctionCall(typoutputfunc, val);
outputstr = OidOutputFunctionCall(outfuncoid, val);
if (key_scalar && *outputstr == '\0')
ereport(ERROR,
(errcode(ERRCODE_INVALID_PARAMETER_VALUE),
......@@ -1308,8 +1408,8 @@ datum_to_json(Datum val, bool is_null, StringInfo result,
*/
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)
bool *nulls, int *valcount, JsonTypeCategory tcategory,
Oid outfuncoid, bool use_line_feeds)
{
int i;
const char *sep;
......@@ -1328,7 +1428,7 @@ array_dim_to_json(StringInfo result, int dim, int ndims, int *dims, Datum *vals,
if (dim + 1 == ndims)
{
datum_to_json(vals[*valcount], nulls[*valcount], result, tcategory,
typoutputfunc, false);
outfuncoid, false);
(*valcount)++;
}
else
......@@ -1338,7 +1438,7 @@ array_dim_to_json(StringInfo result, int dim, int ndims, int *dims, Datum *vals,
* we'll say no.
*/
array_dim_to_json(result, dim + 1, ndims, dims, vals, nulls,
valcount, tcategory, typoutputfunc, false);
valcount, tcategory, outfuncoid, false);
}
}
......@@ -1361,12 +1461,9 @@ array_to_json_internal(Datum array, StringInfo result, bool use_line_feeds)
bool *nulls;
int16 typlen;
bool typbyval;
char typalign,
typdelim;
Oid typioparam;
Oid typoutputfunc;
TYPCATEGORY tcategory;
Oid castfunc = InvalidOid;
char typalign;
JsonTypeCategory tcategory;
Oid outfuncoid;
ndim = ARR_NDIM(v);
dim = ARR_DIMS(v);
......@@ -1378,44 +1475,18 @@ array_to_json_internal(Datum array, StringInfo result, bool use_line_feeds)
return;
}
get_type_io_data(element_type, IOFunc_output,
&typlen, &typbyval, &typalign,
&typdelim, &typioparam, &typoutputfunc);
if (element_type > FirstNormalObjectId)
{
HeapTuple tuple;
Form_pg_cast castForm;
tuple = SearchSysCache2(CASTSOURCETARGET,
ObjectIdGetDatum(element_type),
ObjectIdGetDatum(JSONOID));
if (HeapTupleIsValid(tuple))
{
castForm = (Form_pg_cast) GETSTRUCT(tuple);
if (castForm->castmethod == COERCION_METHOD_FUNCTION)
castfunc = typoutputfunc = castForm->castfunc;
get_typlenbyvalalign(element_type,
&typlen, &typbyval, &typalign);
ReleaseSysCache(tuple);
}
}
json_categorize_type(element_type,
&tcategory, &outfuncoid);
deconstruct_array(v, element_type, typlen, typbyval,
typalign, &elements, &nulls,
&nitems);
if (castfunc != InvalidOid)
tcategory = TYPCATEGORY_JSON_CAST;
else if (element_type == RECORDOID)
tcategory = TYPCATEGORY_COMPOSITE;
else if (element_type == JSONOID || element_type == JSONBOID)
tcategory = TYPCATEGORY_JSON;
else
tcategory = TypeCategory(element_type);
array_dim_to_json(result, 0, ndim, dim, elements, nulls, &count, tcategory,
typoutputfunc, use_line_feeds);
outfuncoid, use_line_feeds);
pfree(elements);
pfree(nulls);
......@@ -1458,10 +1529,8 @@ composite_to_json(Datum composite, StringInfo result, bool use_line_feeds)
Datum val;
bool isnull;
char *attname;
TYPCATEGORY tcategory;
Oid typoutput;
bool typisvarlena;
Oid castfunc = InvalidOid;
JsonTypeCategory tcategory;
Oid outfuncoid;
if (tupdesc->attrs[i]->attisdropped)
continue;
......@@ -1476,41 +1545,16 @@ composite_to_json(Datum composite, StringInfo result, bool use_line_feeds)
val = heap_getattr(tuple, i + 1, tupdesc, &isnull);
getTypeOutputInfo(tupdesc->attrs[i]->atttypid,
&typoutput, &typisvarlena);
if (tupdesc->attrs[i]->atttypid > FirstNormalObjectId)
if (isnull)
{
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);
}
tcategory = JSONTYPE_NULL;
outfuncoid = InvalidOid;
}
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 ||
tupdesc->attrs[i]->atttypid == JSONBOID)
tcategory = TYPCATEGORY_JSON;
else
tcategory = TypeCategory(tupdesc->attrs[i]->atttypid);
json_categorize_type(tupdesc->attrs[i]->atttypid,
&tcategory, &outfuncoid);
datum_to_json(val, isnull, result, tcategory, typoutput, false);
datum_to_json(val, isnull, result, tcategory, outfuncoid, false);
}
appendStringInfoChar(result, '}');
......@@ -1518,65 +1562,34 @@ composite_to_json(Datum composite, StringInfo result, bool use_line_feeds)
}
/*
* append Json for orig_val to result. If it's a field key, make sure it's
* of an acceptable type and is quoted.
* Append JSON text for "val" to "result".
*
* This is just a thin wrapper around datum_to_json. 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_json(Datum val, bool is_null, StringInfo result, Oid val_type, bool key_scalar)
add_json(Datum val, bool is_null, StringInfo result,
Oid val_type, bool key_scalar)
{
TYPCATEGORY tcategory;
Oid typoutput;
bool typisvarlena;
Oid castfunc = InvalidOid;
JsonTypeCategory tcategory;
Oid outfuncoid;
if (val_type == InvalidOid)
ereport(ERROR,
(errcode(ERRCODE_INVALID_PARAMETER_VALUE),
errmsg("could not determine input data type")));
getTypeOutputInfo(val_type, &typoutput, &typisvarlena);
if (val_type > FirstNormalObjectId)
if (is_null)
{
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);
}
tcategory = JSONTYPE_NULL;
outfuncoid = InvalidOid;
}
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 || val_type == JSONBOID)
tcategory = TYPCATEGORY_JSON;
else
tcategory = TypeCategory(val_type);
json_categorize_type(val_type,
&tcategory, &outfuncoid);
if (key_scalar &&
(tcategory == TYPCATEGORY_ARRAY ||
tcategory == TYPCATEGORY_COMPOSITE ||
tcategory == TYPCATEGORY_JSON ||
tcategory == TYPCATEGORY_JSON_CAST))
ereport(ERROR,
(errcode(ERRCODE_INVALID_PARAMETER_VALUE),
errmsg("key value must be scalar, not array, composite or json")));
datum_to_json(val, is_null, result, tcategory, typoutput, key_scalar);
datum_to_json(val, is_null, result, tcategory, outfuncoid, key_scalar);
}
/*
......@@ -1654,51 +1667,20 @@ 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;
JsonTypeCategory tcategory;
Oid outfuncoid;
if (val_type == InvalidOid)
ereport(ERROR,
(errcode(ERRCODE_INVALID_PARAMETER_VALUE),
errmsg("could not determine input data type")));
result = makeStringInfo();
json_categorize_type(val_type,
&tcategory, &outfuncoid);
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 || val_type == JSONBOID)
tcategory = TYPCATEGORY_JSON;
else
tcategory = TypeCategory(val_type);
result = makeStringInfo();
datum_to_json(val, false, result, tcategory, typoutput, false);
datum_to_json(val, false, result, tcategory, outfuncoid, false);
PG_RETURN_TEXT_P(cstring_to_text_with_len(result->data, result->len));
}
......@@ -1714,10 +1696,8 @@ json_agg_transfn(PG_FUNCTION_ARGS)
oldcontext;
StringInfo state;
Datum val;
TYPCATEGORY tcategory;
Oid typoutput;
bool typisvarlena;
Oid castfunc = InvalidOid;
JsonTypeCategory tcategory;
Oid outfuncoid;
if (val_type == InvalidOid)
ereport(ERROR,
......@@ -1734,9 +1714,9 @@ json_agg_transfn(PG_FUNCTION_ARGS)
{
/*
* 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.
* duration of the aggregate call. MemoryContextSwitchTo is only
* needed the first time, as the StringInfo routines make sure they
* use the right context to enlarge the object if necessary.
*/
oldcontext = MemoryContextSwitchTo(aggcontext);
state = makeStringInfo();
......@@ -1753,52 +1733,24 @@ json_agg_transfn(PG_FUNCTION_ARGS)
/* fast path for NULLs */
if (PG_ARGISNULL(1))
{
val = (Datum) 0;
datum_to_json(val, true, state, 0, InvalidOid, false);
datum_to_json((Datum) 0, true, state, JSONTYPE_NULL, InvalidOid, false);
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 || val_type == JSONBOID)
tcategory = TYPCATEGORY_JSON;
else
tcategory = TypeCategory(val_type);
/* XXX we do this every time?? */
json_categorize_type(val_type,
&tcategory, &outfuncoid);
/* add some whitespace if structured type and not first item */
if (!PG_ARGISNULL(0) &&
(tcategory == TYPCATEGORY_ARRAY || tcategory == TYPCATEGORY_COMPOSITE))
(tcategory == JSONTYPE_ARRAY || tcategory == JSONTYPE_COMPOSITE))
{
appendStringInfoString(state, "\n ");
}
datum_to_json(val, false, state, tcategory, typoutput, false);
datum_to_json(val, false, state, tcategory, outfuncoid, false);
/*
* The transition type for array_agg() is declared to be "internal", which
......
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