beagle r4777 - trunk/beagle/Util

[dbera svn gnome org]

Author: dbera
Date: Wed Jun 11 03:14:28 2008
New Revision: 4777
URL: http://svn.gnome.org/viewvc/beagle?rev=4777&view=rev

Log:
Cleanup our Uri handling methods.

* Uri.Fragment is treated differently than Uri.Path (based on when to escape and when to not). Make the API explicit if the fragment needs to be escaped.

* Previous UriToEscapedString (which was converted from a legacy code) did some juggling with the scheme, hostname etc. and then merely appended the path and the fragment. This worked since we always create Uris where the path and the fragment are escaped.

Now, instead of duplicating efforts, we either return the original string used to create the already escaped Uri or we use the AbsoluteUri (which is more correct than uri.ToString()). For our path Uris, we really want the string we used to create the path-uri, so that works as before. For the rest, AbsoluteUri makes sure the Uri is already escaped which is what the earlier method would have done.


Modified:
   trunk/beagle/Util/UriFu.cs

Modified: trunk/beagle/Util/UriFu.cs
==============================================================================
--- trunk/beagle/Util/UriFu.cs	(original)
+++ trunk/beagle/Util/UriFu.cs	Wed Jun 11 03:14:28 2008
@@ -1,6 +1,7 @@
 //
 // UriFu.cs
 //
+// Copyright (C) 2008 D Bera <dbera web gmail com>
 // Copyright (C) 2004 Novell, Inc.
 //
 
@@ -31,70 +32,93 @@
 
 namespace Beagle.Util {
 
-	public class UriFu {
+	/* Beagle URIs : A bunch of hacks
+	 * ------------------------------
+	 *
+	 * Every indexed document is identified by a URI.
+	 * In general URI format is not very flexible so we
+	 * construct our own URI format and convince System.Uri
+	 * to use that. Also, we do our own URI<->string conversion
+	 * and use that during XML serialization/deserialization.
+	 *
+	 * The format is similar to the Uri RFC:
+	 *
+	 * Scheme
+	 * SchemeDelimiter
+	 * Userinfo
+	 * Host (case sensitive - different from the RFC)
+	 * Absolute path and query (escaped)
+	 * Zero or more fragments: each fragment is
+	 *   - '#' (unescaped)
+	 *   - fragment path (escaped)
+	 *
+	 * The difference is the presence of multiple fragments
+	 * and case-sensitive hostname.
+	 *
+	 * Also there are a bunch of functions for converting a
+	 * file path to a file:/// URI. This is needed because
+	 * sometimes path can contain characters prohibited
+	 * in the path component of a URI. These paths first need
+	 * to be escaped. Otherwise Uri() will think these are
+	 * special characters!
+	 *
+	 * Note: Beagle internal uris are of the form "uid:xyz".
+	 *
+	 */
 
-		private UriFu () { } // class is static
+	public static class UriFu {
 
 		static public Uri PathToFileUri (string path)
 		{
-			return PathToFileUri (path, null);
+			return new Uri (PathToFileUriString (path), true);
 		}
 
-		static public Uri PathToFileUri (string path, string fragment)
-		{
-			return new Uri (PathToFileUriString (path, fragment), true);
-		}
+		// DEPRECATED! path is always escaped but escaping of fragment is
+		// context dependent.
+		//static public Uri PathToFileUri (string path, string fragment)
+		//
 
-		static public string PathToFileUriString (string path)
+		// Whether fragment should be escaped or not is crucial and depends on the context.
+		// Hence the caller of the method should set it accordingly and no default
+		// value for escape_fragment is provided.
+		static public Uri AddFragment (Uri uri, string fragment, bool dont_escape_fragment)
 		{
-			return PathToFileUriString (path, null);
+			if (fragment [0] == '#')
+				fragment = fragment.Substring (1);
+
+			if (! dont_escape_fragment)
+				fragment = StringFu.HexEscape (fragment);
+
+			fragment = String.Concat (uri.Fragment,
+						  '#',
+						  fragment); // Append to existing fragment
+
+			return new Uri (uri, fragment, true /* dont escape*/);
 		}
 
-		static public string PathToFileUriString (string path, string fragment)
+		static public string PathToFileUriString (string path)
 		{
-			string str = String.Concat (Uri.UriSchemeFile,
-						    Uri.SchemeDelimiter,
-						    StringFu.HexEscape (Path.GetFullPath (path)));
-			if (fragment != null)
-				str = str + fragment;
-			return str;
+			return String.Concat (Uri.UriSchemeFile,
+					      Uri.SchemeDelimiter,
+					      StringFu.HexEscape (Path.GetFullPath (path)));
 		}
 
-		static public Uri EscapedStringToUri (string path)
+		static public Uri EscapedStringToUri (string uri_string)
 		{
-			// Our current hackery attempts to serialize Uri strings in
-			// escaped and constructable form, so we don't require any
-			// extra processing on deserialization right now.
-			return new Uri (path, true);
+			return new Uri (uri_string, true);
 		}
 
-		// UriBuilder is a piece of shit so we have to do this ourselves.
 		static public string UriToEscapedString (Uri uri)
 		{
-			StringBuilder builder = new StringBuilder ();
-
-			builder.Append (uri.Scheme);
+			if (uri.UserEscaped)
+				return uri.OriginalString;
 
-			if (uri.ToString ().IndexOf (Uri.SchemeDelimiter) == uri.Scheme.Length)
-				builder.Append (Uri.SchemeDelimiter);
-			else
-				builder.Append (':');
-
-			if (uri.Host != String.Empty) {
-				if (uri.UserInfo != String.Empty)
-					builder.Append (uri.UserInfo + "@");
-
-				builder.Append (uri.Host);
-			}
-
-			if (! uri.IsDefaultPort)
-				builder.Append (":" + uri.Port);
-
-			// Both PathAndQuery and Fragment are escaped for us
-			builder.Append (uri.PathAndQuery);
-			builder.Append (uri.Fragment);
-
-			return builder.ToString ();
+			// Do not use uri.ToString(), it actually unescapes certain characters.
+			// uri.AbsoluteUri also returns "uid:xxx" from the beagle internal
+			// uid:xxx URIs.
+			// If AbsoluteUri is found to skip any information in the URI, then
+			// manually the string needs to be constructed.
+			return uri.AbsoluteUri;
 		}
 
 		// Get a uri of our liking from a user-entered uri
@@ -135,6 +159,8 @@
 
 		//////////////////////////////////
 
+		// Uri.ToString() should not be used. Use Uri.AbsoluteUri
+
 		static public bool Equals (Uri uri1, Uri uri2)
 		{
 			return uri1.ToString () == uri2.ToString ();