Adding upstream version 14.5.upstream/14.5upstream

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 610 insertions, 0 deletions

diff --git a/src/backend/utils/adt/enum.c b/src/backend/utils/adt/enum.c
new file mode 100644
index 0000000..0d89213
--- /dev/null
+++ b/src/backend/utils/adt/enum.c
@@ -0,0 +1,610 @@
+/*-------------------------------------------------------------------------
+ *
+ * enum.c
+ *	  I/O functions, operators, aggregates etc for enum types
+ *
+ * Copyright (c) 2006-2021, PostgreSQL Global Development Group
+ *
+ *
+ * IDENTIFICATION
+ *	  src/backend/utils/adt/enum.c
+ *
+ *-------------------------------------------------------------------------
+ */
+#include "postgres.h"
+
+#include "access/genam.h"
+#include "access/htup_details.h"
+#include "access/table.h"
+#include "catalog/pg_enum.h"
+#include "libpq/pqformat.h"
+#include "storage/procarray.h"
+#include "utils/array.h"
+#include "utils/builtins.h"
+#include "utils/fmgroids.h"
+#include "utils/snapmgr.h"
+#include "utils/syscache.h"
+#include "utils/typcache.h"
+
+
+static Oid	enum_endpoint(Oid enumtypoid, ScanDirection direction);
+static ArrayType *enum_range_internal(Oid enumtypoid, Oid lower, Oid upper);
+
+
+/*
+ * Disallow use of an uncommitted pg_enum tuple.
+ *
+ * We need to make sure that uncommitted enum values don't get into indexes.
+ * If they did, and if we then rolled back the pg_enum addition, we'd have
+ * broken the index because value comparisons will not work reliably without
+ * an underlying pg_enum entry.  (Note that removal of the heap entry
+ * containing an enum value is not sufficient to ensure that it doesn't appear
+ * in upper levels of indexes.)  To do this we prevent an uncommitted row from
+ * being used for any SQL-level purpose.  This is stronger than necessary,
+ * since the value might not be getting inserted into a table or there might
+ * be no index on its column, but it's easy to enforce centrally.
+ *
+ * However, it's okay to allow use of uncommitted values belonging to enum
+ * types that were themselves created in the same transaction, because then
+ * any such index would also be new and would go away altogether on rollback.
+ * We don't implement that fully right now, but we do allow free use of enum
+ * values created during CREATE TYPE AS ENUM, which are surely of the same
+ * lifespan as the enum type.  (This case is required by "pg_restore -1".)
+ * Values added by ALTER TYPE ADD VALUE are currently restricted, but could
+ * be allowed if the enum type could be proven to have been created earlier
+ * in the same transaction.  (Note that comparing tuple xmins would not work
+ * for that, because the type tuple might have been updated in the current
+ * transaction.  Subtransactions also create hazards to be accounted for.)
+ *
+ * This function needs to be called (directly or indirectly) in any of the
+ * functions below that could return an enum value to SQL operations.
+ */
+static void
+check_safe_enum_use(HeapTuple enumval_tup)
+{
+	TransactionId xmin;
+	Form_pg_enum en = (Form_pg_enum) GETSTRUCT(enumval_tup);
+
+	/*
+	 * If the row is hinted as committed, it's surely safe.  This provides a
+	 * fast path for all normal use-cases.
+	 */
+	if (HeapTupleHeaderXminCommitted(enumval_tup->t_data))
+		return;
+
+	/*
+	 * Usually, a row would get hinted as committed when it's read or loaded
+	 * into syscache; but just in case not, let's check the xmin directly.
+	 */
+	xmin = HeapTupleHeaderGetXmin(enumval_tup->t_data);
+	if (!TransactionIdIsInProgress(xmin) &&
+		TransactionIdDidCommit(xmin))
+		return;
+
+	/*
+	 * Check if the enum value is uncommitted.  If not, it's safe, because it
+	 * was made during CREATE TYPE AS ENUM and can't be shorter-lived than its
+	 * owning type.  (This'd also be false for values made by other
+	 * transactions; but the previous tests should have handled all of those.)
+	 */
+	if (!EnumUncommitted(en->oid))
+		return;
+
+	/*
+	 * There might well be other tests we could do here to narrow down the
+	 * unsafe conditions, but for now just raise an exception.
+	 */
+	ereport(ERROR,
+			(errcode(ERRCODE_UNSAFE_NEW_ENUM_VALUE_USAGE),
+			 errmsg("unsafe use of new value \"%s\" of enum type %s",
+					NameStr(en->enumlabel),
+					format_type_be(en->enumtypid)),
+			 errhint("New enum values must be committed before they can be used.")));
+}
+
+
+/* Basic I/O support */
+
+Datum
+enum_in(PG_FUNCTION_ARGS)
+{
+	char	   *name = PG_GETARG_CSTRING(0);
+	Oid			enumtypoid = PG_GETARG_OID(1);
+	Oid			enumoid;
+	HeapTuple	tup;
+
+	/* must check length to prevent Assert failure within SearchSysCache */
+	if (strlen(name) >= NAMEDATALEN)
+		ereport(ERROR,
+				(errcode(ERRCODE_INVALID_TEXT_REPRESENTATION),
+				 errmsg("invalid input value for enum %s: \"%s\"",
+						format_type_be(enumtypoid),
+						name)));
+
+	tup = SearchSysCache2(ENUMTYPOIDNAME,
+						  ObjectIdGetDatum(enumtypoid),
+						  CStringGetDatum(name));
+	if (!HeapTupleIsValid(tup))
+		ereport(ERROR,
+				(errcode(ERRCODE_INVALID_TEXT_REPRESENTATION),
+				 errmsg("invalid input value for enum %s: \"%s\"",
+						format_type_be(enumtypoid),
+						name)));
+
+	/* check it's safe to use in SQL */
+	check_safe_enum_use(tup);
+
+	/*
+	 * This comes from pg_enum.oid and stores system oids in user tables. This
+	 * oid must be preserved by binary upgrades.
+	 */
+	enumoid = ((Form_pg_enum) GETSTRUCT(tup))->oid;
+
+	ReleaseSysCache(tup);
+
+	PG_RETURN_OID(enumoid);
+}
+
+Datum
+enum_out(PG_FUNCTION_ARGS)
+{
+	Oid			enumval = PG_GETARG_OID(0);
+	char	   *result;
+	HeapTuple	tup;
+	Form_pg_enum en;
+
+	tup = SearchSysCache1(ENUMOID, ObjectIdGetDatum(enumval));
+	if (!HeapTupleIsValid(tup))
+		ereport(ERROR,
+				(errcode(ERRCODE_INVALID_BINARY_REPRESENTATION),
+				 errmsg("invalid internal value for enum: %u",
+						enumval)));
+	en = (Form_pg_enum) GETSTRUCT(tup);
+
+	result = pstrdup(NameStr(en->enumlabel));
+
+	ReleaseSysCache(tup);
+
+	PG_RETURN_CSTRING(result);
+}
+
+/* Binary I/O support */
+Datum
+enum_recv(PG_FUNCTION_ARGS)
+{
+	StringInfo	buf = (StringInfo) PG_GETARG_POINTER(0);
+	Oid			enumtypoid = PG_GETARG_OID(1);
+	Oid			enumoid;
+	HeapTuple	tup;
+	char	   *name;
+	int			nbytes;
+
+	name = pq_getmsgtext(buf, buf->len - buf->cursor, &nbytes);
+
+	/* must check length to prevent Assert failure within SearchSysCache */
+	if (strlen(name) >= NAMEDATALEN)
+		ereport(ERROR,
+				(errcode(ERRCODE_INVALID_TEXT_REPRESENTATION),
+				 errmsg("invalid input value for enum %s: \"%s\"",
+						format_type_be(enumtypoid),
+						name)));
+
+	tup = SearchSysCache2(ENUMTYPOIDNAME,
+						  ObjectIdGetDatum(enumtypoid),
+						  CStringGetDatum(name));
+	if (!HeapTupleIsValid(tup))
+		ereport(ERROR,
+				(errcode(ERRCODE_INVALID_TEXT_REPRESENTATION),
+				 errmsg("invalid input value for enum %s: \"%s\"",
+						format_type_be(enumtypoid),
+						name)));
+
+	/* check it's safe to use in SQL */
+	check_safe_enum_use(tup);
+
+	enumoid = ((Form_pg_enum) GETSTRUCT(tup))->oid;
+
+	ReleaseSysCache(tup);
+
+	pfree(name);
+
+	PG_RETURN_OID(enumoid);
+}
+
+Datum
+enum_send(PG_FUNCTION_ARGS)
+{
+	Oid			enumval = PG_GETARG_OID(0);
+	StringInfoData buf;
+	HeapTuple	tup;
+	Form_pg_enum en;
+
+	tup = SearchSysCache1(ENUMOID, ObjectIdGetDatum(enumval));
+	if (!HeapTupleIsValid(tup))
+		ereport(ERROR,
+				(errcode(ERRCODE_INVALID_BINARY_REPRESENTATION),
+				 errmsg("invalid internal value for enum: %u",
+						enumval)));
+	en = (Form_pg_enum) GETSTRUCT(tup);
+
+	pq_begintypsend(&buf);
+	pq_sendtext(&buf, NameStr(en->enumlabel), strlen(NameStr(en->enumlabel)));
+
+	ReleaseSysCache(tup);
+
+	PG_RETURN_BYTEA_P(pq_endtypsend(&buf));
+}
+
+/* Comparison functions and related */
+
+/*
+ * enum_cmp_internal is the common engine for all the visible comparison
+ * functions, except for enum_eq and enum_ne which can just check for OID
+ * equality directly.
+ */
+static int
+enum_cmp_internal(Oid arg1, Oid arg2, FunctionCallInfo fcinfo)
+{
+	TypeCacheEntry *tcache;
+
+	/*
+	 * We don't need the typcache except in the hopefully-uncommon case that
+	 * one or both Oids are odd.  This means that cursory testing of code that
+	 * fails to pass flinfo to an enum comparison function might not disclose
+	 * the oversight.  To make such errors more obvious, Assert that we have a
+	 * place to cache even when we take a fast-path exit.
+	 */
+	Assert(fcinfo->flinfo != NULL);
+
+	/* Equal OIDs are equal no matter what */
+	if (arg1 == arg2)
+		return 0;
+
+	/* Fast path: even-numbered Oids are known to compare correctly */
+	if ((arg1 & 1) == 0 && (arg2 & 1) == 0)
+	{
+		if (arg1 < arg2)
+			return -1;
+		else
+			return 1;
+	}
+
+	/* Locate the typcache entry for the enum type */
+	tcache = (TypeCacheEntry *) fcinfo->flinfo->fn_extra;
+	if (tcache == NULL)
+	{
+		HeapTuple	enum_tup;
+		Form_pg_enum en;
+		Oid			typeoid;
+
+		/* Get the OID of the enum type containing arg1 */
+		enum_tup = SearchSysCache1(ENUMOID, ObjectIdGetDatum(arg1));
+		if (!HeapTupleIsValid(enum_tup))
+			ereport(ERROR,
+					(errcode(ERRCODE_INVALID_BINARY_REPRESENTATION),
+					 errmsg("invalid internal value for enum: %u",
+							arg1)));
+		en = (Form_pg_enum) GETSTRUCT(enum_tup);
+		typeoid = en->enumtypid;
+		ReleaseSysCache(enum_tup);
+		/* Now locate and remember the typcache entry */
+		tcache = lookup_type_cache(typeoid, 0);
+		fcinfo->flinfo->fn_extra = (void *) tcache;
+	}
+
+	/* The remaining comparison logic is in typcache.c */
+	return compare_values_of_enum(tcache, arg1, arg2);
+}
+
+Datum
+enum_lt(PG_FUNCTION_ARGS)
+{
+	Oid			a = PG_GETARG_OID(0);
+	Oid			b = PG_GETARG_OID(1);
+
+	PG_RETURN_BOOL(enum_cmp_internal(a, b, fcinfo) < 0);
+}
+
+Datum
+enum_le(PG_FUNCTION_ARGS)
+{
+	Oid			a = PG_GETARG_OID(0);
+	Oid			b = PG_GETARG_OID(1);
+
+	PG_RETURN_BOOL(enum_cmp_internal(a, b, fcinfo) <= 0);
+}
+
+Datum
+enum_eq(PG_FUNCTION_ARGS)
+{
+	Oid			a = PG_GETARG_OID(0);
+	Oid			b = PG_GETARG_OID(1);
+
+	PG_RETURN_BOOL(a == b);
+}
+
+Datum
+enum_ne(PG_FUNCTION_ARGS)
+{
+	Oid			a = PG_GETARG_OID(0);
+	Oid			b = PG_GETARG_OID(1);
+
+	PG_RETURN_BOOL(a != b);
+}
+
+Datum
+enum_ge(PG_FUNCTION_ARGS)
+{
+	Oid			a = PG_GETARG_OID(0);
+	Oid			b = PG_GETARG_OID(1);
+
+	PG_RETURN_BOOL(enum_cmp_internal(a, b, fcinfo) >= 0);
+}
+
+Datum
+enum_gt(PG_FUNCTION_ARGS)
+{
+	Oid			a = PG_GETARG_OID(0);
+	Oid			b = PG_GETARG_OID(1);
+
+	PG_RETURN_BOOL(enum_cmp_internal(a, b, fcinfo) > 0);
+}
+
+Datum
+enum_smaller(PG_FUNCTION_ARGS)
+{
+	Oid			a = PG_GETARG_OID(0);
+	Oid			b = PG_GETARG_OID(1);
+
+	PG_RETURN_OID(enum_cmp_internal(a, b, fcinfo) < 0 ? a : b);
+}
+
+Datum
+enum_larger(PG_FUNCTION_ARGS)
+{
+	Oid			a = PG_GETARG_OID(0);
+	Oid			b = PG_GETARG_OID(1);
+
+	PG_RETURN_OID(enum_cmp_internal(a, b, fcinfo) > 0 ? a : b);
+}
+
+Datum
+enum_cmp(PG_FUNCTION_ARGS)
+{
+	Oid			a = PG_GETARG_OID(0);
+	Oid			b = PG_GETARG_OID(1);
+
+	PG_RETURN_INT32(enum_cmp_internal(a, b, fcinfo));
+}
+
+/* Enum programming support functions */
+
+/*
+ * enum_endpoint: common code for enum_first/enum_last
+ */
+static Oid
+enum_endpoint(Oid enumtypoid, ScanDirection direction)
+{
+	Relation	enum_rel;
+	Relation	enum_idx;
+	SysScanDesc enum_scan;
+	HeapTuple	enum_tuple;
+	ScanKeyData skey;
+	Oid			minmax;
+
+	/*
+	 * Find the first/last enum member using pg_enum_typid_sortorder_index.
+	 * Note we must not use the syscache.  See comments for RenumberEnumType
+	 * in catalog/pg_enum.c for more info.
+	 */
+	ScanKeyInit(&skey,
+				Anum_pg_enum_enumtypid,
+				BTEqualStrategyNumber, F_OIDEQ,
+				ObjectIdGetDatum(enumtypoid));
+
+	enum_rel = table_open(EnumRelationId, AccessShareLock);
+	enum_idx = index_open(EnumTypIdSortOrderIndexId, AccessShareLock);
+	enum_scan = systable_beginscan_ordered(enum_rel, enum_idx, NULL,
+										   1, &skey);
+
+	enum_tuple = systable_getnext_ordered(enum_scan, direction);
+	if (HeapTupleIsValid(enum_tuple))
+	{
+		/* check it's safe to use in SQL */
+		check_safe_enum_use(enum_tuple);
+		minmax = ((Form_pg_enum) GETSTRUCT(enum_tuple))->oid;
+	}
+	else
+	{
+		/* should only happen with an empty enum */
+		minmax = InvalidOid;
+	}
+
+	systable_endscan_ordered(enum_scan);
+	index_close(enum_idx, AccessShareLock);
+	table_close(enum_rel, AccessShareLock);
+
+	return minmax;
+}
+
+Datum
+enum_first(PG_FUNCTION_ARGS)
+{
+	Oid			enumtypoid;
+	Oid			min;
+
+	/*
+	 * We rely on being able to get the specific enum type from the calling
+	 * expression tree.  Notice that the actual value of the argument isn't
+	 * examined at all; in particular it might be NULL.
+	 */
+	enumtypoid = get_fn_expr_argtype(fcinfo->flinfo, 0);
+	if (enumtypoid == InvalidOid)
+		ereport(ERROR,
+				(errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
+				 errmsg("could not determine actual enum type")));
+
+	/* Get the OID using the index */
+	min = enum_endpoint(enumtypoid, ForwardScanDirection);
+
+	if (!OidIsValid(min))
+		ereport(ERROR,
+				(errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+				 errmsg("enum %s contains no values",
+						format_type_be(enumtypoid))));
+
+	PG_RETURN_OID(min);
+}
+
+Datum
+enum_last(PG_FUNCTION_ARGS)
+{
+	Oid			enumtypoid;
+	Oid			max;
+
+	/*
+	 * We rely on being able to get the specific enum type from the calling
+	 * expression tree.  Notice that the actual value of the argument isn't
+	 * examined at all; in particular it might be NULL.
+	 */
+	enumtypoid = get_fn_expr_argtype(fcinfo->flinfo, 0);
+	if (enumtypoid == InvalidOid)
+		ereport(ERROR,
+				(errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
+				 errmsg("could not determine actual enum type")));
+
+	/* Get the OID using the index */
+	max = enum_endpoint(enumtypoid, BackwardScanDirection);
+
+	if (!OidIsValid(max))
+		ereport(ERROR,
+				(errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+				 errmsg("enum %s contains no values",
+						format_type_be(enumtypoid))));
+
+	PG_RETURN_OID(max);
+}
+
+/* 2-argument variant of enum_range */
+Datum
+enum_range_bounds(PG_FUNCTION_ARGS)
+{
+	Oid			lower;
+	Oid			upper;
+	Oid			enumtypoid;
+
+	if (PG_ARGISNULL(0))
+		lower = InvalidOid;
+	else
+		lower = PG_GETARG_OID(0);
+	if (PG_ARGISNULL(1))
+		upper = InvalidOid;
+	else
+		upper = PG_GETARG_OID(1);
+
+	/*
+	 * We rely on being able to get the specific enum type from the calling
+	 * expression tree.  The generic type mechanism should have ensured that
+	 * both are of the same type.
+	 */
+	enumtypoid = get_fn_expr_argtype(fcinfo->flinfo, 0);
+	if (enumtypoid == InvalidOid)
+		ereport(ERROR,
+				(errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
+				 errmsg("could not determine actual enum type")));
+
+	PG_RETURN_ARRAYTYPE_P(enum_range_internal(enumtypoid, lower, upper));
+}
+
+/* 1-argument variant of enum_range */
+Datum
+enum_range_all(PG_FUNCTION_ARGS)
+{
+	Oid			enumtypoid;
+
+	/*
+	 * We rely on being able to get the specific enum type from the calling
+	 * expression tree.  Notice that the actual value of the argument isn't
+	 * examined at all; in particular it might be NULL.
+	 */
+	enumtypoid = get_fn_expr_argtype(fcinfo->flinfo, 0);
+	if (enumtypoid == InvalidOid)
+		ereport(ERROR,
+				(errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
+				 errmsg("could not determine actual enum type")));
+
+	PG_RETURN_ARRAYTYPE_P(enum_range_internal(enumtypoid,
+											  InvalidOid, InvalidOid));
+}
+
+static ArrayType *
+enum_range_internal(Oid enumtypoid, Oid lower, Oid upper)
+{
+	ArrayType  *result;
+	Relation	enum_rel;
+	Relation	enum_idx;
+	SysScanDesc enum_scan;
+	HeapTuple	enum_tuple;
+	ScanKeyData skey;
+	Datum	   *elems;
+	int			max,
+				cnt;
+	bool		left_found;
+
+	/*
+	 * Scan the enum members in order using pg_enum_typid_sortorder_index.
+	 * Note we must not use the syscache.  See comments for RenumberEnumType
+	 * in catalog/pg_enum.c for more info.
+	 */
+	ScanKeyInit(&skey,
+				Anum_pg_enum_enumtypid,
+				BTEqualStrategyNumber, F_OIDEQ,
+				ObjectIdGetDatum(enumtypoid));
+
+	enum_rel = table_open(EnumRelationId, AccessShareLock);
+	enum_idx = index_open(EnumTypIdSortOrderIndexId, AccessShareLock);
+	enum_scan = systable_beginscan_ordered(enum_rel, enum_idx, NULL, 1, &skey);
+
+	max = 64;
+	elems = (Datum *) palloc(max * sizeof(Datum));
+	cnt = 0;
+	left_found = !OidIsValid(lower);
+
+	while (HeapTupleIsValid(enum_tuple = systable_getnext_ordered(enum_scan, ForwardScanDirection)))
+	{
+		Oid			enum_oid = ((Form_pg_enum) GETSTRUCT(enum_tuple))->oid;
+
+		if (!left_found && lower == enum_oid)
+			left_found = true;
+
+		if (left_found)
+		{
+			/* check it's safe to use in SQL */
+			check_safe_enum_use(enum_tuple);
+
+			if (cnt >= max)
+			{
+				max *= 2;
+				elems = (Datum *) repalloc(elems, max * sizeof(Datum));
+			}
+
+			elems[cnt++] = ObjectIdGetDatum(enum_oid);
+		}
+
+		if (OidIsValid(upper) && upper == enum_oid)
+			break;
+	}
+
+	systable_endscan_ordered(enum_scan);
+	index_close(enum_idx, AccessShareLock);
+	table_close(enum_rel, AccessShareLock);
+
+	/* and build the result array */
+	/* note this hardwires some details about the representation of Oid */
+	result = construct_array(elems, cnt, enumtypoid,
+							 sizeof(Oid), true, TYPALIGN_INT);
+
+	pfree(elems);
+
+	return result;
+}