1 files changed, 117 insertions, 0 deletions
diff --git a/src/backend/access/common/scankey.c b/src/backend/access/common/scankey.c
new file mode 100644
index 0000000..bf33c50
--- /dev/null
+++ b/src/backend/access/common/scankey.c
@@ -0,0 +1,117 @@
+/*-------------------------------------------------------------------------
+ *
+ * scankey.c
+ *	  scan key support code
+ *
+ * Portions Copyright (c) 1996-2021, PostgreSQL Global Development Group
+ * Portions Copyright (c) 1994, Regents of the University of California
+ *
+ *
+ * IDENTIFICATION
+ *	  src/backend/access/common/scankey.c
+ *
+ *-------------------------------------------------------------------------
+ */
+#include "postgres.h"
+
+#include "access/skey.h"
+#include "catalog/pg_collation.h"
+
+
+/*
+ * ScanKeyEntryInitialize
+ *		Initializes a scan key entry given all the field values.
+ *		The target procedure is specified by OID (but can be invalid
+ *		if SK_SEARCHNULL or SK_SEARCHNOTNULL is set).
+ *
+ * Note: CurrentMemoryContext at call should be as long-lived as the ScanKey
+ * itself, because that's what will be used for any subsidiary info attached
+ * to the ScanKey's FmgrInfo record.
+ */
+void
+ScanKeyEntryInitialize(ScanKey entry,
+					   int flags,
+					   AttrNumber attributeNumber,
+					   StrategyNumber strategy,
+					   Oid subtype,
+					   Oid collation,
+					   RegProcedure procedure,
+					   Datum argument)
+{
+	entry->sk_flags = flags;
+	entry->sk_attno = attributeNumber;
+	entry->sk_strategy = strategy;
+	entry->sk_subtype = subtype;
+	entry->sk_collation = collation;
+	entry->sk_argument = argument;
+	if (RegProcedureIsValid(procedure))
+	{
+		fmgr_info(procedure, &entry->sk_func);
+	}
+	else
+	{
+		Assert(flags & (SK_SEARCHNULL | SK_SEARCHNOTNULL));
+		MemSet(&entry->sk_func, 0, sizeof(entry->sk_func));
+	}
+}
+
+/*
+ * ScanKeyInit
+ *		Shorthand version of ScanKeyEntryInitialize: flags and subtype
+ *		are assumed to be zero (the usual value), and collation is defaulted.
+ *
+ * This is the recommended version for hardwired lookups in system catalogs.
+ * It cannot handle NULL arguments, unary operators, or nondefault operators,
+ * but we need none of those features for most hardwired lookups.
+ *
+ * We set collation to C_COLLATION_OID always.  This is the correct value
+ * for all collation-aware columns in system catalogs, and it will be ignored
+ * for other column types, so it's not worth trying to be more finicky.
+ *
+ * Note: CurrentMemoryContext at call should be as long-lived as the ScanKey
+ * itself, because that's what will be used for any subsidiary info attached
+ * to the ScanKey's FmgrInfo record.
+ */
+void
+ScanKeyInit(ScanKey entry,
+			AttrNumber attributeNumber,
+			StrategyNumber strategy,
+			RegProcedure procedure,
+			Datum argument)
+{
+	entry->sk_flags = 0;
+	entry->sk_attno = attributeNumber;
+	entry->sk_strategy = strategy;
+	entry->sk_subtype = InvalidOid;
+	entry->sk_collation = C_COLLATION_OID;
+	entry->sk_argument = argument;
+	fmgr_info(procedure, &entry->sk_func);
+}
+
+/*
+ * ScanKeyEntryInitializeWithInfo
+ *		Initializes a scan key entry using an already-completed FmgrInfo
+ *		function lookup record.
+ *
+ * Note: CurrentMemoryContext at call should be as long-lived as the ScanKey
+ * itself, because that's what will be used for any subsidiary info attached
+ * to the ScanKey's FmgrInfo record.
+ */
+void
+ScanKeyEntryInitializeWithInfo(ScanKey entry,
+							   int flags,
+							   AttrNumber attributeNumber,
+							   StrategyNumber strategy,
+							   Oid subtype,
+							   Oid collation,
+							   FmgrInfo *finfo,
+							   Datum argument)
+{
+	entry->sk_flags = flags;
+	entry->sk_attno = attributeNumber;
+	entry->sk_strategy = strategy;
+	entry->sk_subtype = subtype;
+	entry->sk_collation = collation;
+	entry->sk_argument = argument;
+	fmgr_info_copy(&entry->sk_func, finfo, CurrentMemoryContext);
+}