1 files changed, 39 insertions, 0 deletions
diff --git a/contrib/ltree/crc32.c b/contrib/ltree/crc32.c
new file mode 100644
index 0000000..8fed334
--- /dev/null
+++ b/contrib/ltree/crc32.c
@@ -0,0 +1,39 @@
+/* contrib/ltree/crc32.c */
+
+/*
+ * Implements CRC-32, as used in ltree.
+ *
+ * Note that the CRC is used in the on-disk format of GiST indexes, so we
+ * must stay backwards-compatible!
+ */
+
+#include "postgres.h"
+
+#ifdef LOWER_NODE
+#include <ctype.h>
+#define TOLOWER(x)	tolower((unsigned char) (x))
+#else
+#define TOLOWER(x)	(x)
+#endif
+
+#include "crc32.h"
+#include "utils/pg_crc.h"
+
+unsigned int
+ltree_crc32_sz(const char *buf, int size)
+{
+	pg_crc32	crc;
+	const char *p = buf;
+
+	INIT_TRADITIONAL_CRC32(crc);
+	while (size > 0)
+	{
+		char		c = (char) TOLOWER(*p);
+
+		COMP_TRADITIONAL_CRC32(crc, &c, 1);
+		size--;
+		p++;
+	}
+	FIN_TRADITIONAL_CRC32(crc);
+	return (unsigned int) crc;
+}