Added support for DESC and NULLS FIRST/LAST to index keys

Fixes issue #3

bin/expected/repack.out

@@ -314,3 +314,35 @@ ERROR: relation "tbl_uk" must have a primary key or not-null unique keys
 \! pg_repack --dbname=contrib_regression --no-order --table=tbl_nn_puk
 ERROR: relation "tbl_nn_puk" must have a primary key or not-null unique keys
 -- => ERROR
+--
+-- pg_repack issue #3
+--
+CREATE TABLE issue3 (col1 int NOT NULL, col2 text NOT NULL);
+CREATE UNIQUE INDEX issue3_idx1 ON issue3 (col1, col2 DESC);
+CREATE UNIQUE INDEX issue3_idx2 ON issue3 (col1 DESC, col2 text_pattern_ops);
+CREATE UNIQUE INDEX issue3_idx3 ON issue3 (col1 DESC, col2 DESC);
+CREATE UNIQUE INDEX issue3_idx4 ON issue3 (col1 NULLS FIRST, col2 text_pattern_ops DESC NULLS LAST);
+SELECT repack.get_index_keys('issue3_idx1'::regclass::oid, 'issue3'::regclass::oid);
+ get_index_keys  
+-----------------
+ col1, col2 DESC
+(1 row)
+
+SELECT repack.get_index_keys('issue3_idx2'::regclass::oid, 'issue3'::regclass::oid);
+      get_index_keys       
+---------------------------
+ col1 DESC, col2 USING ~<~
+(1 row)
+
+SELECT repack.get_index_keys('issue3_idx3'::regclass::oid, 'issue3'::regclass::oid);
+    get_index_keys    
+----------------------
+ col1 DESC, col2 DESC
+(1 row)
+
+SELECT repack.get_index_keys('issue3_idx4'::regclass::oid, 'issue3'::regclass::oid);
+                  get_index_keys                  
+--------------------------------------------------
+ col1 NULLS FIRST, col2 DESC USING ~<~ NULLS LAST
+(1 row)
+

bin/sql/repack.sql

@@ -187,3 +187,17 @@ CREATE UNIQUE INDEX tbl_nn_puk_pcol1_idx ON tbl_nn_puk(col1) WHERE col1 < 10;
 -- => OK
 \! pg_repack --dbname=contrib_regression --no-order --table=tbl_nn_puk
 -- => ERROR
+
+--
+-- pg_repack issue #3
+--
+CREATE TABLE issue3 (col1 int NOT NULL, col2 text NOT NULL);
+CREATE UNIQUE INDEX issue3_idx1 ON issue3 (col1, col2 DESC);
+CREATE UNIQUE INDEX issue3_idx2 ON issue3 (col1 DESC, col2 text_pattern_ops);
+CREATE UNIQUE INDEX issue3_idx3 ON issue3 (col1 DESC, col2 DESC);
+CREATE UNIQUE INDEX issue3_idx4 ON issue3 (col1 NULLS FIRST, col2 text_pattern_ops DESC NULLS LAST);
+
+SELECT repack.get_index_keys('issue3_idx1'::regclass::oid, 'issue3'::regclass::oid);
+SELECT repack.get_index_keys('issue3_idx2'::regclass::oid, 'issue3'::regclass::oid);
+SELECT repack.get_index_keys('issue3_idx3'::regclass::oid, 'issue3'::regclass::oid);
+SELECT repack.get_index_keys('issue3_idx4'::regclass::oid, 'issue3'::regclass::oid);

lib/repack.c

@@ -472,6 +472,36 @@ parse_indexdef(IndexDef *stmt, Oid index, Oid table)
 	stmt->options = sql;
 }
 
+/*
+ * Parse the trailing ... [ DESC ] [ NULLS { FIRST | LAST } ] from an index
+ * definition column.
+ * Returned values point to token. \0's are inserted to separate parsed parts.
+ */
+static void
+parse_desc_nulls(char *token, char **desc, char **nulls)
+{
+#if PG_VERSION_NUM >= 80300
+	char *pos;
+
+	/* easier to walk backwards than to parse quotes and escapes... */
+	if (NULL != (pos = strstr(token, " NULLS FIRST")))
+	{
+		*nulls = pos + 1;
+		*pos = '\0';
+	}
+	else if (NULL != (pos = strstr(token, " NULLS LAST")))
+	{
+		*nulls = pos + 1;
+		*pos = '\0';
+	}
+	if (NULL != (pos = strstr(token, " DESC")))
+	{
+		*desc = pos + 1;
+		*pos = '\0';
+	}
+#endif
+}
+
 /**
  * @fn      Datum repack_get_index_keys(PG_FUNCTION_ARGS)
  * @brief   Get key definition of the index.
@@ -514,12 +544,18 @@ repack_get_index_keys(PG_FUNCTION_ARGS)
 	for (nattr = 0, next = stmt.columns; next; nattr++)
 	{
 		char *opcname;
+		char *coldesc = NULL;
+		char *colnulls = NULL;
 
 		token = next;
 		while (isspace((unsigned char) *token))
 			token++;
 		next = skip_until(index, next, ',');
+		parse_desc_nulls(token, &coldesc, &colnulls);
 		opcname = skip_until(index, token, ' ');
+		appendStringInfoString(&str, token);
+		if (coldesc)
+			appendStringInfo(&str, " %s", coldesc);
 		if (opcname)
 		{
 			/* lookup default operator name from operator class */
@@ -556,12 +592,11 @@ repack_get_index_keys(PG_FUNCTION_ARGS)
 				elog(ERROR, "missing operator %d(%u,%u) in opfamily %u",
 					 strategy, opcintype, opcintype, opfamily);
 
-
 			opcname[-1] = '\0';
-			appendStringInfo(&str, "%s USING %s", token, get_opname(oprid));
+			appendStringInfo(&str, " USING %s", get_opname(oprid));
 		}
-		else
+		if (colnulls)
-			appendStringInfoString(&str, token);
+			appendStringInfo(&str, " %s", colnulls);
 		if (next)
 			appendStringInfoString(&str, ", ");
 	}