/*
* getBaseType
* If the given type is a domain, return its base type;
* otherwise return the type's own OID.
*/
Oid
getBaseType(Oid typid)
{
int32 typmod = -1;
return getBaseTypeAndTypmod(typid, &typmod);
}
/*
* SendRowDescriptionMessage --- send a RowDescription message to the frontend
*
* Notes: the TupleDesc has typically been manufactured by ExecTypeFromTL()
* or some similar function; it does not contain a full set of fields.
* The targetlist will be NIL when executing a utility function that does
* not have a plan. If the targetlist isn't NIL then it is a Query node's
* targetlist; it is up to us to ignore resjunk columns in it. The formats[]
* array pointer might be NULL (if we are doing Describe on a prepared stmt);
* send zeroes for the format codes in that case.
*/
void
SendRowDescriptionMessage(TupleDesc typeinfo, List *targetlist, int16 *formats)
{
Form_pg_attribute *attrs = typeinfo->attrs;
int natts = typeinfo->natts;
int proto = PG_PROTOCOL_MAJOR(FrontendProtocol);
int i;
StringInfoData buf;
ListCell *tlist_item = list_head(targetlist);
pq_beginmessage(&buf, 'T'); /* tuple descriptor message type */
pq_sendint(&buf, natts, 2); /* # of attrs in tuples */
for (i = 0; i < natts; ++i)
{
Oid atttypid = attrs[i]->atttypid;
int32 atttypmod = attrs[i]->atttypmod;
pq_sendstring(&buf, NameStr(attrs[i]->attname));
/* column ID info appears in protocol 3.0 and up */
if (proto >= 3)
{
/* Do we have a non-resjunk tlist item? */
while (tlist_item &&
((TargetEntry *) lfirst(tlist_item))->resjunk)
tlist_item = lnext(tlist_item);
if (tlist_item)
{
TargetEntry *tle = (TargetEntry *) lfirst(tlist_item);
pq_sendint(&buf, tle->resorigtbl, 4);
pq_sendint(&buf, tle->resorigcol, 2);
tlist_item = lnext(tlist_item);
}
else
{
/* No info available, so send zeroes */
pq_sendint(&buf, 0, 4);
pq_sendint(&buf, 0, 2);
}
}
/* If column is a domain, send the base type and typmod instead */
atttypid = getBaseTypeAndTypmod(atttypid, &atttypmod);
pq_sendint(&buf, (int) atttypid, sizeof(atttypid));
pq_sendint(&buf, attrs[i]->attlen, sizeof(attrs[i]->attlen));
/* typmod appears in protocol 2.0 and up */
if (proto >= 2)
pq_sendint(&buf, atttypmod, sizeof(atttypmod));
/* format info appears in protocol 3.0 and up */
if (proto >= 3)
{
if (formats)
pq_sendint(&buf, formats[i], 2);
else
pq_sendint(&buf, 0, 2);
}
}
pq_endmessage(&buf);
}
/*
* transformArrayType()
* Identify the types involved in a subscripting operation
*
* On entry, arrayType/arrayTypmod identify the type of the input value
* to be subscripted (which could be a domain type). These are modified
* if necessary to identify the actual array type and typmod, and the
* array's element type is returned. An error is thrown if the input isn't
* an array type.
*/
Oid
transformArrayType(Oid *arrayType, int32 *arrayTypmod)
{
Oid origArrayType = *arrayType;
Oid elementType;
HeapTuple type_tuple_array;
Form_pg_type type_struct_array;
/*
* If the input is a domain, smash to base type, and extract the actual
* typmod to be applied to the base type. Subscripting a domain is an
* operation that necessarily works on the base array type, not the domain
* itself. (Note that we provide no method whereby the creator of a
* domain over an array type could hide its ability to be subscripted.)
*/
*arrayType = getBaseTypeAndTypmod(*arrayType, arrayTypmod);
/*
* We treat int2vector and oidvector as though they were domains over
* int2[] and oid[]. This is needed because array slicing could create an
* array that doesn't satisfy the dimensionality constraints of the
* xxxvector type; so we want the result of a slice operation to be
* considered to be of the more general type.
*/
if (*arrayType == INT2VECTOROID)
*arrayType = INT2ARRAYOID;
else if (*arrayType == OIDVECTOROID)
*arrayType = OIDARRAYOID;
/* Get the type tuple for the array */
type_tuple_array = SearchSysCache1(TYPEOID, ObjectIdGetDatum(*arrayType));
if (!HeapTupleIsValid(type_tuple_array))
elog(ERROR, "cache lookup failed for type %u", *arrayType);
type_struct_array = (Form_pg_type) GETSTRUCT(type_tuple_array);
/* needn't check typisdefined since this will fail anyway */
elementType = type_struct_array->typelem;
if (elementType == InvalidOid)
ereport(ERROR,
(errcode(ERRCODE_DATATYPE_MISMATCH),
errmsg("cannot subscript type %s because it is not an array",
format_type_be(origArrayType))));
ReleaseSysCache(type_tuple_array);
return elementType;
}
/*
* Send description for each column when using v2 protocol
*/
static void
SendRowDescriptionCols_2(StringInfo buf, TupleDesc typeinfo, List *targetlist, int16 *formats)
{
int natts = typeinfo->natts;
int i;
for (i = 0; i < natts; ++i)
{
Form_pg_attribute att = TupleDescAttr(typeinfo, i);
Oid atttypid = att->atttypid;
int32 atttypmod = att->atttypmod;
/* If column is a domain, send the base type and typmod instead */
atttypid = getBaseTypeAndTypmod(atttypid, &atttypmod);
pq_sendstring(buf, NameStr(att->attname));
/* column ID only info appears in protocol 3.0 and up */
pq_sendint32(buf, atttypid);
pq_sendint16(buf, att->attlen);
pq_sendint32(buf, atttypmod);
/* format info only appears in protocol 3.0 and up */
}
}
/*
* transformArrayType()
* Identify the types involved in a subscripting operation
*
* On entry, arrayType/arrayTypmod identify the type of the input value
* to be subscripted (which could be a domain type). These are modified
* if necessary to identify the actual array type and typmod, and the
* array's element type is returned. An error is thrown if the input isn't
* an array type.
*/
Oid
transformArrayType(Oid *arrayType, int32 *arrayTypmod)
{
Oid origArrayType = *arrayType;
Oid elementType;
HeapTuple type_tuple_array;
Form_pg_type type_struct_array;
/*
* If the input is a domain, smash to base type, and extract the actual
* typmod to be applied to the base type. Subscripting a domain is an
* operation that necessarily works on the base array type, not the domain
* itself. (Note that we provide no method whereby the creator of a
* domain over an array type could hide its ability to be subscripted.)
*/
*arrayType = getBaseTypeAndTypmod(*arrayType, arrayTypmod);
/* Get the type tuple for the array */
type_tuple_array = SearchSysCache1(TYPEOID, ObjectIdGetDatum(*arrayType));
if (!HeapTupleIsValid(type_tuple_array))
elog(ERROR, "cache lookup failed for type %u", *arrayType);
type_struct_array = (Form_pg_type) GETSTRUCT(type_tuple_array);
/* needn't check typisdefined since this will fail anyway */
elementType = type_struct_array->typelem;
if (elementType == InvalidOid)
ereport(ERROR,
(errcode(ERRCODE_DATATYPE_MISMATCH),
errmsg("cannot subscript type %s because it is not an array",
format_type_be(origArrayType))));
ReleaseSysCache(type_tuple_array);
return elementType;
}
/*
* Send description for each column when using v3+ protocol
*/
static void
SendRowDescriptionCols_3(StringInfo buf, TupleDesc typeinfo, List *targetlist, int16 *formats)
{
int natts = typeinfo->natts;
int i;
ListCell *tlist_item = list_head(targetlist);
/*
* Preallocate memory for the entire message to be sent. That allows to
* use the significantly faster inline pqformat.h functions and to avoid
* reallocations.
*
* Have to overestimate the size of the column-names, to account for
* character set overhead.
*/
enlargeStringInfo(buf, (NAMEDATALEN * MAX_CONVERSION_GROWTH /* attname */
+ sizeof(Oid) /* resorigtbl */
+ sizeof(AttrNumber) /* resorigcol */
+ sizeof(Oid) /* atttypid */
+ sizeof(int16) /* attlen */
+ sizeof(int32) /* attypmod */
+ sizeof(int16) /* format */
) * natts);
for (i = 0; i < natts; ++i)
{
Form_pg_attribute att = TupleDescAttr(typeinfo, i);
Oid atttypid = att->atttypid;
int32 atttypmod = att->atttypmod;
Oid resorigtbl;
AttrNumber resorigcol;
int16 format;
/*
* If column is a domain, send the base type and typmod instead.
* Lookup before sending any ints, for efficiency.
*/
atttypid = getBaseTypeAndTypmod(atttypid, &atttypmod);
/* Do we have a non-resjunk tlist item? */
while (tlist_item &&
((TargetEntry *) lfirst(tlist_item))->resjunk)
tlist_item = lnext(tlist_item);
if (tlist_item)
{
TargetEntry *tle = (TargetEntry *) lfirst(tlist_item);
resorigtbl = tle->resorigtbl;
resorigcol = tle->resorigcol;
tlist_item = lnext(tlist_item);
}
else
{
/* No info available, so send zeroes */
resorigtbl = 0;
resorigcol = 0;
}
if (formats)
format = formats[i];
else
format = 0;
pq_writestring(buf, NameStr(att->attname));
pq_writeint32(buf, resorigtbl);
pq_writeint16(buf, resorigcol);
pq_writeint32(buf, atttypid);
pq_writeint16(buf, att->attlen);
pq_writeint32(buf, atttypmod);
pq_writeint16(buf, format);
}
}
/*
* SendRowDescriptionMessage --- send a RowDescription message to the frontend
*
* Notes: the TupleDesc has typically been manufactured by ExecTypeFromTL()
* or some similar function; it does not contain a full set of fields.
* The targetlist will be NIL when executing a utility function that does
* not have a plan. If the targetlist isn't NIL then it is a Query node's
* targetlist; it is up to us to ignore resjunk columns in it. The formats[]
* array pointer might be NULL (if we are doing Describe on a prepared stmt);
* send zeroes for the format codes in that case.
*/
void
SendRowDescriptionMessage(TupleDesc typeinfo, List *targetlist, int16 *formats)
{
Form_pg_attribute *attrs = typeinfo->attrs;
int natts = typeinfo->natts;
int proto = PG_PROTOCOL_MAJOR(FrontendProtocol);
int i;
StringInfoData buf;
ListCell *tlist_item = list_head(targetlist);
pq_beginmessage(&buf, 'T'); /* tuple descriptor message type */
pq_sendint(&buf, natts, 2); /* # of attrs in tuples */
for (i = 0; i < natts; ++i)
{
Oid atttypid = attrs[i]->atttypid;
int32 atttypmod = attrs[i]->atttypmod;
pq_sendstring(&buf, NameStr(attrs[i]->attname));
#ifdef PGXC
/*
* Send the type name from a Postgres-XC backend node.
* This preserves from OID inconsistencies as architecture is shared nothing.
*/
if (IsConnFromCoord())
{
char *typenamespace = NULL;
char *typename;
Oid nspid;
nspid = get_typenamespace(atttypid);
if (OidIsValid(nspid) && nspid != PG_CATALOG_NAMESPACE)
{
typenamespace = get_namespace_name(nspid);
}
typename = get_typename(atttypid);
pq_sendstring(&buf, quote_qualified_identifier(typenamespace,
typename));
}
#endif
/* column ID info appears in protocol 3.0 and up */
if (proto >= 3)
{
/* Do we have a non-resjunk tlist item? */
while (tlist_item &&
((TargetEntry *) lfirst(tlist_item))->resjunk)
tlist_item = lnext(tlist_item);
if (tlist_item)
{
TargetEntry *tle = (TargetEntry *) lfirst(tlist_item);
pq_sendint(&buf, tle->resorigtbl, 4);
pq_sendint(&buf, tle->resorigcol, 2);
tlist_item = lnext(tlist_item);
}
else
{
/* No info available, so send zeroes */
pq_sendint(&buf, 0, 4);
pq_sendint(&buf, 0, 2);
}
}
/* If column is a domain, send the base type and typmod instead */
atttypid = getBaseTypeAndTypmod(atttypid, &atttypmod);
pq_sendint(&buf, (int) atttypid, sizeof(atttypid));
pq_sendint(&buf, attrs[i]->attlen, sizeof(attrs[i]->attlen));
/* typmod appears in protocol 2.0 and up */
if (proto >= 2)
pq_sendint(&buf, atttypmod, sizeof(atttypmod));
/* format info appears in protocol 3.0 and up */
if (proto >= 3)
{
if (formats)
pq_sendint(&buf, formats[i], 2);
else
pq_sendint(&buf, 0, 2);
}
}
pq_endmessage(&buf);
}
