Add a new, improved version of citext as a contrib module.

David E. Wheeler

1 files changed, 268 insertions, 0 deletions

diff --git a/contrib/citext/citext.c b/contrib/citext/citext.c
new file mode 100644
index 00000000000..eb885c0037e
--- /dev/null
+++ b/contrib/citext/citext.c
@@ -0,0 +1,268 @@
+/*
+ * $PostgreSQL: pgsql/contrib/citext/citext.c,v 1.1 2008/07/29 18:31:20 tgl Exp $
+ */
+#include "postgres.h"
+
+#include "access/hash.h"
+#include "fmgr.h"
+#include "utils/builtins.h"
+#include "utils/formatting.h"
+
+#ifdef PG_MODULE_MAGIC
+PG_MODULE_MAGIC;
+#endif
+
+/*
+ *      ====================
+ *      FORWARD DECLARATIONS
+ *      ====================
+ */
+
+static int32  citextcmp      (text *left, text *right);
+extern Datum  citext_cmp     (PG_FUNCTION_ARGS);
+extern Datum  citext_hash    (PG_FUNCTION_ARGS);
+extern Datum  citext_eq      (PG_FUNCTION_ARGS);
+extern Datum  citext_ne      (PG_FUNCTION_ARGS);
+extern Datum  citext_gt      (PG_FUNCTION_ARGS);
+extern Datum  citext_ge      (PG_FUNCTION_ARGS);
+extern Datum  citext_lt      (PG_FUNCTION_ARGS);
+extern Datum  citext_le      (PG_FUNCTION_ARGS);
+extern Datum  citext_smaller (PG_FUNCTION_ARGS);
+extern Datum  citext_larger  (PG_FUNCTION_ARGS);
+
+/*
+ *      =================
+ *      UTILITY FUNCTIONS
+ *      =================
+ */
+
+/*
+ * citextcmp()
+ * Internal comparison function for citext strings.
+ * Returns int32 negative, zero, or positive.
+ */
+static int32
+citextcmp (text *left, text *right)
+{
+   char   *lcstr, *rcstr;
+   int32	result;
+
+   lcstr = str_tolower(VARDATA_ANY(left), VARSIZE_ANY_EXHDR(left));
+   rcstr = str_tolower(VARDATA_ANY(right), VARSIZE_ANY_EXHDR(right));
+
+   result = varstr_cmp(lcstr, strlen(lcstr),
+					   rcstr, strlen(rcstr));
+
+   pfree(lcstr);
+   pfree(rcstr);
+
+   return result;
+}
+
+/*
+ *      ==================
+ *      INDEXING FUNCTIONS
+ *      ==================
+ */
+
+PG_FUNCTION_INFO_V1(citext_cmp);
+
+Datum
+citext_cmp(PG_FUNCTION_ARGS)
+{
+   text *left  = PG_GETARG_TEXT_PP(0);
+   text *right = PG_GETARG_TEXT_PP(1);
+   int32 result;
+
+   result = citextcmp(left, right);
+
+   PG_FREE_IF_COPY(left, 0);
+   PG_FREE_IF_COPY(right, 1);
+
+   PG_RETURN_INT32(result);
+}
+
+PG_FUNCTION_INFO_V1(citext_hash);
+
+Datum
+citext_hash(PG_FUNCTION_ARGS)
+{
+   text       *txt = PG_GETARG_TEXT_PP(0);
+   char       *str;
+   Datum       result;
+
+   str    = str_tolower(VARDATA_ANY(txt), VARSIZE_ANY_EXHDR(txt));
+   result = hash_any((unsigned char *) str, strlen(str));
+   pfree(str);
+
+   /* Avoid leaking memory for toasted inputs */
+   PG_FREE_IF_COPY(txt, 0);
+
+   PG_RETURN_DATUM(result);
+}
+
+/*
+ *      ==================
+ *      OPERATOR FUNCTIONS
+ *      ==================
+ */
+
+PG_FUNCTION_INFO_V1(citext_eq);
+
+Datum
+citext_eq(PG_FUNCTION_ARGS)
+{
+   text *left  = PG_GETARG_TEXT_PP(0);
+   text *right = PG_GETARG_TEXT_PP(1);
+   char *lcstr, *rcstr;
+   bool  result;
+
+   /* We can't compare lengths in advance of downcasing ... */
+
+   lcstr = str_tolower(VARDATA_ANY(left), VARSIZE_ANY_EXHDR(left));
+   rcstr = str_tolower(VARDATA_ANY(right), VARSIZE_ANY_EXHDR(right));
+
+   /*
+    * Since we only care about equality or not-equality, we can
+    * avoid all the expense of strcoll() here, and just do bitwise
+    * comparison.
+    */
+   result = (strcmp(lcstr, rcstr) == 0);
+
+   pfree(lcstr);
+   pfree(rcstr);
+   PG_FREE_IF_COPY(left, 0);
+   PG_FREE_IF_COPY(right, 1);
+
+   PG_RETURN_BOOL(result);
+}
+
+PG_FUNCTION_INFO_V1(citext_ne);
+
+Datum
+citext_ne(PG_FUNCTION_ARGS)
+{
+   text *left  = PG_GETARG_TEXT_PP(0);
+   text *right = PG_GETARG_TEXT_PP(1);
+   char *lcstr, *rcstr;
+   bool  result;
+
+   /* We can't compare lengths in advance of downcasing ... */
+
+   lcstr = str_tolower(VARDATA_ANY(left), VARSIZE_ANY_EXHDR(left));
+   rcstr = str_tolower(VARDATA_ANY(right), VARSIZE_ANY_EXHDR(right));
+
+   /*
+    * Since we only care about equality or not-equality, we can
+    * avoid all the expense of strcoll() here, and just do bitwise
+    * comparison.
+    */
+   result = (strcmp(lcstr, rcstr) != 0);
+
+   pfree(lcstr);
+   pfree(rcstr);
+   PG_FREE_IF_COPY(left, 0);
+   PG_FREE_IF_COPY(right, 1);
+
+   PG_RETURN_BOOL(result);
+}
+
+PG_FUNCTION_INFO_V1(citext_lt);
+
+Datum
+citext_lt(PG_FUNCTION_ARGS)
+{
+   text *left  = PG_GETARG_TEXT_PP(0);
+   text *right = PG_GETARG_TEXT_PP(1);
+   bool  result;
+
+   result = citextcmp(left, right) < 0;
+
+   PG_FREE_IF_COPY(left, 0);
+   PG_FREE_IF_COPY(right, 1);
+
+   PG_RETURN_BOOL(result);
+}
+
+PG_FUNCTION_INFO_V1(citext_le);
+
+Datum
+citext_le(PG_FUNCTION_ARGS)
+{
+   text *left  = PG_GETARG_TEXT_PP(0);
+   text *right = PG_GETARG_TEXT_PP(1);
+   bool  result;
+
+   result = citextcmp(left, right) <= 0;
+
+   PG_FREE_IF_COPY(left, 0);
+   PG_FREE_IF_COPY(right, 1);
+
+   PG_RETURN_BOOL(result);
+}
+
+PG_FUNCTION_INFO_V1(citext_gt);
+
+Datum
+citext_gt(PG_FUNCTION_ARGS)
+{
+   text *left  = PG_GETARG_TEXT_PP(0);
+   text *right = PG_GETARG_TEXT_PP(1);
+   bool  result;
+
+   result = citextcmp(left, right) > 0;
+
+   PG_FREE_IF_COPY(left, 0);
+   PG_FREE_IF_COPY(right, 1);
+
+   PG_RETURN_BOOL(result);
+}
+
+PG_FUNCTION_INFO_V1(citext_ge);
+
+Datum
+citext_ge(PG_FUNCTION_ARGS)
+{
+   text *left  = PG_GETARG_TEXT_PP(0);
+   text *right = PG_GETARG_TEXT_PP(1);
+   bool  result;
+
+   result = citextcmp(left, right) >= 0;
+
+   PG_FREE_IF_COPY(left, 0);
+   PG_FREE_IF_COPY(right, 1);
+
+   PG_RETURN_BOOL(result);
+}
+
+/*
+ *      ===================
+ *      AGGREGATE FUNCTIONS
+ *      ===================
+ */
+
+PG_FUNCTION_INFO_V1(citext_smaller);
+
+Datum
+citext_smaller(PG_FUNCTION_ARGS)
+{
+   text *left  = PG_GETARG_TEXT_PP(0);
+   text *right = PG_GETARG_TEXT_PP(1);
+   text *result;
+
+   result = citextcmp(left, right) < 0 ? left : right;
+   PG_RETURN_TEXT_P(result);
+}
+
+PG_FUNCTION_INFO_V1(citext_larger);
+
+Datum
+citext_larger(PG_FUNCTION_ARGS)
+{
+   text *left  = PG_GETARG_TEXT_PP(0);
+   text *right = PG_GETARG_TEXT_PP(1);
+   text *result;
+
+   result = citextcmp(left, right) > 0 ? left : right;
+   PG_RETURN_TEXT_P(result);
+}