1 files changed, 80 insertions, 0 deletions
diff --git a/src/backend/utils/adt/pg_locale_builtin.c b/src/backend/utils/adt/pg_locale_builtin.c
index 4246971a4d8..d3aa7bceacd 100644
--- a/src/backend/utils/adt/pg_locale_builtin.c
+++ b/src/backend/utils/adt/pg_locale_builtin.c
@@ -13,6 +13,8 @@
 
 #include "catalog/pg_database.h"
 #include "catalog/pg_collation.h"
+#include "common/unicode_case.h"
+#include "common/unicode_category.h"
 #include "mb/pg_wchar.h"
 #include "miscadmin.h"
 #include "utils/builtins.h"
@@ -22,6 +24,84 @@
 
 extern pg_locale_t create_pg_locale_builtin(Oid collid,
 											MemoryContext context);
+extern size_t strlower_builtin(char *dst, size_t dstsize, const char *src,
+							   ssize_t srclen, pg_locale_t locale);
+extern size_t strtitle_builtin(char *dst, size_t dstsize, const char *src,
+							   ssize_t srclen, pg_locale_t locale);
+extern size_t strupper_builtin(char *dst, size_t dstsize, const char *src,
+							   ssize_t srclen, pg_locale_t locale);
+
+
+struct WordBoundaryState
+{
+	const char *str;
+	size_t		len;
+	size_t		offset;
+	bool		init;
+	bool		prev_alnum;
+};
+
+/*
+ * Simple word boundary iterator that draws boundaries each time the result of
+ * pg_u_isalnum() changes.
+ */
+static size_t
+initcap_wbnext(void *state)
+{
+	struct WordBoundaryState *wbstate = (struct WordBoundaryState *) state;
+
+	while (wbstate->offset < wbstate->len &&
+		   wbstate->str[wbstate->offset] != '\0')
+	{
+		pg_wchar	u = utf8_to_unicode((unsigned char *) wbstate->str +
+										wbstate->offset);
+		bool		curr_alnum = pg_u_isalnum(u, true);
+
+		if (!wbstate->init || curr_alnum != wbstate->prev_alnum)
+		{
+			size_t		prev_offset = wbstate->offset;
+
+			wbstate->init = true;
+			wbstate->offset += unicode_utf8len(u);
+			wbstate->prev_alnum = curr_alnum;
+			return prev_offset;
+		}
+
+		wbstate->offset += unicode_utf8len(u);
+	}
+
+	return wbstate->len;
+}
+
+size_t
+strlower_builtin(char *dest, size_t destsize, const char *src, ssize_t srclen,
+				 pg_locale_t locale)
+{
+	return unicode_strlower(dest, destsize, src, srclen);
+}
+
+size_t
+strtitle_builtin(char *dest, size_t destsize, const char *src, ssize_t srclen,
+				 pg_locale_t locale)
+{
+	struct WordBoundaryState wbstate = {
+		.str = src,
+		.len = srclen,
+		.offset = 0,
+		.init = false,
+		.prev_alnum = false,
+	};
+
+	return unicode_strtitle(dest, destsize, src, srclen,
+							initcap_wbnext, &wbstate);
+}
+
+size_t
+strupper_builtin(char *dest, size_t destsize, const char *src, ssize_t srclen,
+				 pg_locale_t locale)
+{
+	return unicode_strupper(dest, destsize, src, srclen);
+}
 
 pg_locale_t
 create_pg_locale_builtin(Oid collid, MemoryContext context)