Add uri_normalize function

README.md

@@ -110,3 +110,19 @@ A number of functions are provided to extract parts of a URI:
 
     Extracts the fragment part of a URI (roughly speaking, everything
     after the `#`).  If there is no fragment part, returns null.
+
+Other functions:
+
+- `uri_normalize(uri) returns uri`
+
+    Performs syntax-based normalization of the URI.  This includes
+    case normalization, percent-encoding normalization, and removing
+    redundant `.` and `..` path segments.  See
+    [RFC 3986 section 6.2.2](http://tools.ietf.org/html/rfc3986#section-6.2.2)
+    for the full details.
+
+    Note that this module (and similar modules in other programming
+    languages) compares URIs for equality in their original form,
+    without normalization.  If you want to consider distinct URIs
+    without regard for mostly irrelevant syntax differences, pass them
+    through this function.

test/expected/test.out

@@ -16,6 +16,11 @@ VALUES ('http://www.postgresql.org/'),
        ('/'),
        ('foobar'),
        ('/foobar');
+-- normalization test values from <https://tools.ietf.org/html/rfc3986#section-6.2.2>
+INSERT INTO test (b)
+VALUES ('HTTP://www.EXAMPLE.com/'),
+       ('http://www.ex%41mple.com/'),
+       ('eXAMPLE://a/./b/../b/%63/%7bfoo%7d');
 SELECT * FROM test;
  a  |                                            b                                            
 ----+-----------------------------------------------------------------------------------------
@@ -33,7 +38,10 @@ SELECT * FROM test;
  12 | /
  13 | foobar
  14 | /foobar
-(14 rows)
+ 15 | HTTP://www.EXAMPLE.com/
+ 16 | http://www.ex%41mple.com/
+ 17 | eXAMPLE://a/./b/../b/%63/%7bfoo%7d
+(17 rows)
 
 -- error cases
 SELECT uri 'http://host:port/';
@@ -42,6 +50,7 @@ LINE 1: SELECT uri 'http://host:port/';
                    ^
 \x on
 SELECT b AS uri,
+       uri_normalize(b),
        uri_scheme(b),
        uri_userinfo(b),
        uri_host(b),
@@ -54,6 +63,7 @@ SELECT b AS uri,
   FROM test;
 -[ RECORD 1 ]--+----------------------------------------------------------------------------------------
 uri            | http://www.postgresql.org/
+uri_normalize  | http://www.postgresql.org/
 uri_scheme     | http
 uri_userinfo   | _null_
 uri_host       | www.postgresql.org
@@ -65,6 +75,7 @@ uri_query      | _null_
 uri_fragment   | _null_
 -[ RECORD 2 ]--+----------------------------------------------------------------------------------------
 uri            | http://www.postgresql.org/docs/devel/static/xfunc-sql.html#XFUNC-SQL-FUNCTION-ARGUMENTS
+uri_normalize  | http://www.postgresql.org/docs/devel/static/xfunc-sql.html#XFUNC-SQL-FUNCTION-ARGUMENTS
 uri_scheme     | http
 uri_userinfo   | _null_
 uri_host       | www.postgresql.org
@@ -76,6 +87,7 @@ uri_query      | _null_
 uri_fragment   | XFUNC-SQL-FUNCTION-ARGUMENTS
 -[ RECORD 3 ]--+----------------------------------------------------------------------------------------
 uri            | https://duckduckgo.com/?q=postgresql&ia=about
+uri_normalize  | https://duckduckgo.com/?q=postgresql&ia=about
 uri_scheme     | https
 uri_userinfo   | _null_
 uri_host       | duckduckgo.com
@@ -87,6 +99,7 @@ uri_query      | q=postgresql&ia=about
 uri_fragment   | _null_
 -[ RECORD 4 ]--+----------------------------------------------------------------------------------------
 uri            | ftp://ftp.gnu.org/gnu/bison
+uri_normalize  | ftp://ftp.gnu.org/gnu/bison
 uri_scheme     | ftp
 uri_userinfo   | _null_
 uri_host       | ftp.gnu.org
@@ -98,6 +111,7 @@ uri_query      | _null_
 uri_fragment   | _null_
 -[ RECORD 5 ]--+----------------------------------------------------------------------------------------
 uri            | mailto:foo@example.com
+uri_normalize  | mailto:foo@example.com
 uri_scheme     | mailto
 uri_userinfo   | _null_
 uri_host       | _null_
@@ -109,6 +123,7 @@ uri_query      | _null_
 uri_fragment   | _null_
 -[ RECORD 6 ]--+----------------------------------------------------------------------------------------
 uri            | ssh://username@review.openstack.org:29418/openstack/nova.git
+uri_normalize  | ssh://username@review.openstack.org:29418/openstack/nova.git
 uri_scheme     | ssh
 uri_userinfo   | username
 uri_host       | review.openstack.org
@@ -120,6 +135,7 @@ uri_query      | _null_
 uri_fragment   | _null_
 -[ RECORD 7 ]--+----------------------------------------------------------------------------------------
 uri            | http://admin:password@192.168.0.1
+uri_normalize  | http://admin:password@192.168.0.1
 uri_scheme     | http
 uri_userinfo   | admin:password
 uri_host       | 192.168.0.1
@@ -131,6 +147,7 @@ uri_query      | _null_
 uri_fragment   | _null_
 -[ RECORD 8 ]--+----------------------------------------------------------------------------------------
 uri            | http://[FEDC:BA98:7654:3210:FEDC:BA98:7654:3210]:80/index.html
+uri_normalize  | http://[fedc:ba98:7654:3210:fedc:ba98:7654:3210]:80/index.html
 uri_scheme     | http
 uri_userinfo   | _null_
 uri_host       | FEDC:BA98:7654:3210:FEDC:BA98:7654:3210
@@ -142,6 +159,7 @@ uri_query      | _null_
 uri_fragment   | _null_
 -[ RECORD 9 ]--+----------------------------------------------------------------------------------------
 uri            | http://[1080::8:800:200C:417A]/foo
+uri_normalize  | http://[1080:0000:0000:0000:0008:0800:200c:417a]/foo
 uri_scheme     | http
 uri_userinfo   | _null_
 uri_host       | 1080::8:800:200C:417A
@@ -153,6 +171,7 @@ uri_query      | _null_
 uri_fragment   | _null_
 -[ RECORD 10 ]-+----------------------------------------------------------------------------------------
 uri            | http://host:
+uri_normalize  | http://host:
 uri_scheme     | http
 uri_userinfo   | _null_
 uri_host       | host
@@ -164,6 +183,7 @@ uri_query      | _null_
 uri_fragment   | _null_
 -[ RECORD 11 ]-+----------------------------------------------------------------------------------------
 uri            | 
+uri_normalize  | 
 uri_scheme     | _null_
 uri_userinfo   | _null_
 uri_host       | _null_
@@ -175,6 +195,7 @@ uri_query      | _null_
 uri_fragment   | _null_
 -[ RECORD 12 ]-+----------------------------------------------------------------------------------------
 uri            | /
+uri_normalize  | /
 uri_scheme     | _null_
 uri_userinfo   | _null_
 uri_host       | _null_
@@ -186,6 +207,7 @@ uri_query      | _null_
 uri_fragment   | _null_
 -[ RECORD 13 ]-+----------------------------------------------------------------------------------------
 uri            | foobar
+uri_normalize  | foobar
 uri_scheme     | _null_
 uri_userinfo   | _null_
 uri_host       | _null_
@@ -197,6 +219,7 @@ uri_query      | _null_
 uri_fragment   | _null_
 -[ RECORD 14 ]-+----------------------------------------------------------------------------------------
 uri            | /foobar
+uri_normalize  | /foobar
 uri_scheme     | _null_
 uri_userinfo   | _null_
 uri_host       | _null_
@@ -206,6 +229,42 @@ uri_path       | /foobar
 uri_path_array | {foobar}
 uri_query      | _null_
 uri_fragment   | _null_
+-[ RECORD 15 ]-+----------------------------------------------------------------------------------------
+uri            | HTTP://www.EXAMPLE.com/
+uri_normalize  | http://www.example.com/
+uri_scheme     | HTTP
+uri_userinfo   | _null_
+uri_host       | www.EXAMPLE.com
+uri_host_inet  | _null_
+uri_port       | _null_
+uri_path       | /
+uri_path_array | {""}
+uri_query      | _null_
+uri_fragment   | _null_
+-[ RECORD 16 ]-+----------------------------------------------------------------------------------------
+uri            | http://www.ex%41mple.com/
+uri_normalize  | http://www.example.com/
+uri_scheme     | http
+uri_userinfo   | _null_
+uri_host       | www.ex%41mple.com
+uri_host_inet  | _null_
+uri_port       | _null_
+uri_path       | /
+uri_path_array | {""}
+uri_query      | _null_
+uri_fragment   | _null_
+-[ RECORD 17 ]-+----------------------------------------------------------------------------------------
+uri            | eXAMPLE://a/./b/../b/%63/%7bfoo%7d
+uri_normalize  | example://a/b/c/%7Bfoo%7D
+uri_scheme     | eXAMPLE
+uri_userinfo   | _null_
+uri_host       | a
+uri_host_inet  | _null_
+uri_port       | _null_
+uri_path       | /./b/../b/%63/%7bfoo%7d
+uri_path_array | {.,b,..,b,%63,%7bfoo%7d}
+uri_query      | _null_
+uri_fragment   | _null_
 
 \x off
 SELECT DISTINCT b FROM test ORDER BY b;
@@ -214,16 +273,19 @@ SELECT DISTINCT b FROM test ORDER BY b;
  
  /
  /foobar
+ HTTP://www.EXAMPLE.com/
+ eXAMPLE://a/./b/../b/%63/%7bfoo%7d
  foobar
  ftp://ftp.gnu.org/gnu/bison
  http://[1080::8:800:200C:417A]/foo
  http://[FEDC:BA98:7654:3210:FEDC:BA98:7654:3210]:80/index.html
  http://admin:password@192.168.0.1
  http://host:
+ http://www.ex%41mple.com/
  http://www.postgresql.org/
  http://www.postgresql.org/docs/devel/static/xfunc-sql.html#XFUNC-SQL-FUNCTION-ARGUMENTS
  https://duckduckgo.com/?q=postgresql&ia=about
  mailto:foo@example.com
  ssh://username@review.openstack.org:29418/openstack/nova.git
-(14 rows)
+(17 rows)
 

test/sql/test.sql

@@ -20,6 +20,12 @@ VALUES ('http://www.postgresql.org/'),
        ('foobar'),
        ('/foobar');
 
+-- normalization test values from <https://tools.ietf.org/html/rfc3986#section-6.2.2>
+INSERT INTO test (b)
+VALUES ('HTTP://www.EXAMPLE.com/'),
+       ('http://www.ex%41mple.com/'),
+       ('eXAMPLE://a/./b/../b/%63/%7bfoo%7d');
+
 SELECT * FROM test;
 
 -- error cases
@@ -28,6 +34,7 @@ SELECT uri 'http://host:port/';
 
 \x on
 SELECT b AS uri,
+       uri_normalize(b),
        uri_scheme(b),
        uri_userinfo(b),
        uri_host(b),

uri.c

@@ -277,6 +277,35 @@ uri_path_array(PG_FUNCTION_ARGS)
 		PG_RETURN_ARRAYTYPE_P(construct_empty_array(TEXTOID));
 }
 
+PG_FUNCTION_INFO_V1(uri_normalize);
+Datum
+uri_normalize(PG_FUNCTION_ARGS)
+{
+	Datum arg = PG_GETARG_DATUM(0);
+	char *s = TextDatumGetCString(arg);
+	UriUriA uri;
+	int rc;
+	int charsRequired;
+	char *ret;
+
+	parse_uri(s, &uri);
+
+	if ((rc = uriNormalizeSyntaxA(&uri)) != URI_SUCCESS)
+		elog(ERROR, "uriNormalizeSyntaxA() failed: error code %d", rc);
+
+	if ((rc = uriToStringCharsRequiredA(&uri, &charsRequired)) != URI_SUCCESS)
+		elog(ERROR, "uriToStringCharsRequiredA() failed: error code %d", rc);
+	charsRequired++;
+
+	ret = palloc(charsRequired);
+	if ((rc = uriToStringA(ret, &uri, charsRequired, NULL)) != URI_SUCCESS)
+		elog(ERROR, "uriToStringA() failed: error code %d", rc);
+
+	uriFreeUriMembersA(&uri);
+
+	PG_RETURN_URI_P((uritype *) cstring_to_text(ret));
+}
+
 static int
 cmp_text_range(UriTextRangeA a, UriTextRangeA b)
 {

uri.sql

@@ -81,6 +81,13 @@ CREATE FUNCTION uri_path_array(uri) RETURNS text[]
     AS '$libdir/uri';
 
 
+CREATE FUNCTION uri_normalize(uri) RETURNS uri
+    IMMUTABLE
+    STRICT
+    LANGUAGE C
+    AS '$libdir/uri';
+
+
 CREATE FUNCTION uri_lt(uri, uri) RETURNS boolean
     IMMUTABLE
     STRICT