Commit e4b14cc3 authored by Andrés G. Aragoneses's avatar Andrés G. Aragoneses

Playlists: (refactoring) more progress towards immutability

PlaylistParser.Parse() was mutable (the result of its execution was
available at one of the properties of its instance. This can be
avoided by making Parse() static, and return the result instead
of just a bool indicating its success (from now on, a null value
returned means a failure to parse).

To do this, the PlaylistParser class has to be split in two:
- static class PlaylistParser
- DTO class ParsedPlaylist

This doesn't only make the code safer, it allows me to remove
the lock{} inside Parse() method, and makes everything a bit
more readable and maintainable.
parent a715b96e
......@@ -177,10 +177,10 @@ namespace Banshee.Playlist
relative_dir = relative_dir + System.IO.Path.DirectorySeparatorChar;
}
var parser = new PlaylistParser (new Uri (relative_dir));
if (parser.Parse (uri)) {
var parsed_playlist = PlaylistParser.Parse (uri, new Uri (relative_dir));
if (parsed_playlist != null) {
List<string> uris = new List<string> ();
foreach (PlaylistElement element in parser.Elements) {
foreach (PlaylistElement element in parsed_playlist.Elements) {
if (element.Uri.IsFile) {
uris.Add (element.Uri.LocalPath);
} else {
......@@ -211,7 +211,7 @@ namespace Banshee.Playlist
// Only import an non-empty playlist
if (uris.Count > 0) {
ImportPlaylistWorker worker = new ImportPlaylistWorker (
parser.Title,
parsed_playlist.Title,
uris.ToArray (), source, importer);
worker.Import ();
}
......
......@@ -104,8 +104,8 @@ namespace Banshee.Playlists.Formats
case "entryref":
string href = xml_reader["HREF"] ?? xml_reader["href"];
if (href != null) {
PlaylistParser secondary = new PlaylistParser ();
if (secondary.Parse (new SafeUri (ResolveUri (href)))) {
var secondary = PlaylistParser.Parse (new SafeUri (ResolveUri (href)));
if (secondary != null) {
// splice in Elements of secondary
foreach (PlaylistElement e in secondary.Elements) {
Elements.Add (e);
......
//
// ParsedPlaylist.cs
//
// Authors:
// Aaron Bockover <abockover@novell.com>
// Bertrand Lorentz <bertrand.lorentz@gmail.com>
// Andrés G. Aragoneses <knocte@gmail.com>
//
// Copyright (C) 2007 Novell, Inc.
// Copyright (C) 2014 Andrés G. Aragoneses
//
// Permission is hereby granted, free of charge, to any person obtaining
// a copy of this software and associated documentation files (the
// "Software"), to deal in the Software without restriction, including
// without limitation the rights to use, copy, modify, merge, publish,
// distribute, sublicense, and/or sell copies of the Software, and to
// permit persons to whom the Software is furnished to do so, subject to
// the following conditions:
//
// The above copyright notice and this permission notice shall be
// included in all copies or substantial portions of the Software.
//
// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
// EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
// MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
// NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE
// LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION
// OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION
// WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
//
using System.Collections.Generic;
namespace Banshee.Playlists.Formats
{
public class ParsedPlaylist
{
internal ParsedPlaylist (string title, List<PlaylistElement> elements)
{
Title = title;
Elements = elements;
}
public List<PlaylistElement> Elements { get; private set; }
public string Title { get; private set; }
}
}
......@@ -4,8 +4,10 @@
// Authors:
// Aaron Bockover <abockover@novell.com>
// Bertrand Lorentz <bertrand.lorentz@gmail.com>
// Andrés G. Aragoneses <knocte@gmail.com>
//
// Copyright (C) 2007 Novell, Inc.
// Copyright (C) 2014 Andrés G. Aragoneses
//
// Permission is hereby granted, free of charge, to any person obtaining
// a copy of this software and associated documentation files (the
......@@ -30,13 +32,12 @@
using System;
using System.IO;
using System.Net;
using System.Collections.Generic;
using Hyena;
namespace Banshee.Playlists.Formats
{
public class PlaylistParser
public static class PlaylistParser
{
private static PlaylistFormatDescription [] playlist_formats = new PlaylistFormatDescription [] {
M3uPlaylistFormat.FormatDescription,
......@@ -46,111 +47,104 @@ namespace Banshee.Playlists.Formats
XspfPlaylistFormat.FormatDescription
};
private List<PlaylistElement> elements;
private Uri base_uri = null;
private string title = null;
private readonly int HTTP_REQUEST_RETRIES = 3;
private static readonly int HTTP_REQUEST_RETRIES = 3;
public PlaylistParser (Uri baseUri)
public static ParsedPlaylist Parse (SafeUri uri)
{
base_uri = baseUri;
return Parse (uri, null);
}
public PlaylistParser ()
{
if (Environment.CurrentDirectory.Equals ("/")) {
// System.Uri doesn't like / as a value
base_uri = new Uri ("file:///");
} else {
base_uri = new Uri (Environment.CurrentDirectory);
}
}
public bool Parse (SafeUri uri)
public static ParsedPlaylist Parse (SafeUri uri, Uri baseUri)
{
ThreadAssist.AssertNotInMainThread ();
lock (this) {
elements = null;
HttpWebResponse response = null;
Stream stream = null;
Stream web_stream = null;
bool partial_read = false;
long saved_position = 0;
if (uri.Scheme == "file") {
stream = Banshee.IO.File.OpenRead (uri);
} else if (uri.Scheme == "http") {
response = Download (uri, HTTP_REQUEST_RETRIES);
web_stream = response.GetResponseStream ();
try {
stream = new MemoryStream ();
byte [] buffer = new byte[4096];
int read;
// If we haven't read the whole stream and if
// it turns out to be a playlist, we'll read the rest
read = web_stream.Read (buffer, 0, buffer.Length);
stream.Write (buffer, 0, read);
if ((read = web_stream.Read (buffer, 0, buffer.Length)) > 0) {
partial_read = true;
stream.Write (buffer, 0, read);
saved_position = stream.Position;
}
stream.Position = 0;
} finally {
if (!partial_read) {
web_stream.Close ();
response.Close ();
}
}
if (baseUri == null) {
if (Environment.CurrentDirectory.Equals ("/")) {
// System.Uri doesn't like / as a value
baseUri = new Uri ("file:///");
} else {
Hyena.Log.DebugFormat ("Not able to parse playlist at {0}", uri);
return false;
baseUri = new Uri (Environment.CurrentDirectory);
}
}
PlaylistFormatDescription matching_format = null;
HttpWebResponse response = null;
Stream stream = null;
Stream web_stream = null;
bool partial_read = false;
long saved_position = 0;
if (uri.Scheme == "file") {
stream = Banshee.IO.File.OpenRead (uri);
} else if (uri.Scheme == "http") {
response = Download (uri, HTTP_REQUEST_RETRIES);
web_stream = response.GetResponseStream ();
try {
stream = new MemoryStream ();
foreach (PlaylistFormatDescription format in playlist_formats) {
stream.Position = 0;
byte [] buffer = new byte[4096];
int read;
if (format.MagicHandler (new StreamReader (stream))) {
matching_format = format;
break;
// If we haven't read the whole stream and if
// it turns out to be a playlist, we'll read the rest
read = web_stream.Read (buffer, 0, buffer.Length);
stream.Write (buffer, 0, read);
if ((read = web_stream.Read (buffer, 0, buffer.Length)) > 0) {
partial_read = true;
stream.Write (buffer, 0, read);
saved_position = stream.Position;
}
}
if (matching_format == null) {
if (partial_read) {
stream.Position = 0;
} finally {
if (!partial_read) {
web_stream.Close ();
response.Close ();
}
return false;
}
} else {
Hyena.Log.DebugFormat ("Not able to parse playlist at {0}", uri);
return null;
}
PlaylistFormatDescription matching_format = null;
foreach (PlaylistFormatDescription format in playlist_formats) {
stream.Position = 0;
if (format.MagicHandler (new StreamReader (stream))) {
matching_format = format;
break;
}
}
if (matching_format == null) {
if (partial_read) {
try {
stream.Position = saved_position;
Banshee.IO.StreamAssist.Save (web_stream, stream, false);
} finally {
web_stream.Close ();
response.Close ();
}
web_stream.Close ();
response.Close ();
}
stream.Position = 0;
IPlaylistFormat playlist = (IPlaylistFormat)Activator.CreateInstance (matching_format.Type);
playlist.BaseUri = base_uri;
playlist.Load (stream, false);
stream.Dispose ();
elements = playlist.Elements;
Title = playlist.Title ?? Path.GetFileNameWithoutExtension (uri.LocalPath);
return true;
return null;
}
if (partial_read) {
try {
stream.Position = saved_position;
Banshee.IO.StreamAssist.Save (web_stream, stream, false);
} finally {
web_stream.Close ();
response.Close ();
}
}
stream.Position = 0;
IPlaylistFormat playlist = (IPlaylistFormat)Activator.CreateInstance (matching_format.Type);
playlist.BaseUri = baseUri;
playlist.Load (stream, false);
stream.Dispose ();
var title = playlist.Title ?? Path.GetFileNameWithoutExtension (uri.LocalPath);
return new ParsedPlaylist (title, playlist.Elements);
}
private HttpWebResponse Download (SafeUri uri, int nb_retries)
private static HttpWebResponse Download (SafeUri uri, int nb_retries)
{
Hyena.ThreadAssist.AssertNotInMainThread ();
......@@ -193,14 +187,5 @@ namespace Banshee.Playlists.Formats
}
}
}
public List<PlaylistElement> Elements {
get { return elements; }
}
public string Title {
get { return title; }
set { title = value; }
}
}
}
......@@ -96,12 +96,10 @@ namespace Banshee.Playlists.Formats.Tests
[Test]
public void ReadAsxEntryRef ()
{
var parser = new PlaylistParser (BaseUri);
parser.Parse (new SafeUri ("http://download.banshee.fm/test/remote.asx"));
var parsed_playlist = PlaylistParser.Parse (new SafeUri ("http://download.banshee.fm/test/remote.asx"), BaseUri);
IPlaylistFormat plref = LoadPlaylist (new AsxPlaylistFormat (), "entryref.asx");
Assert.AreEqual (2, plref.Elements.Count);
AssertEqual (parser.Elements, plref.Elements);
AssertEqual (parsed_playlist.Elements, plref.Elements);
}
private void AssertEqual (List<PlaylistElement> l1, List<PlaylistElement> l2)
......@@ -159,14 +157,12 @@ namespace Banshee.Playlists.Formats.Tests
[Test]
public void ReadDetectMagic ()
{
var parser = new PlaylistParser (BaseUri);
foreach (string path in Directory.GetFiles (playlists_dir)) {
parser.Parse (new SafeUri (Path.Combine (Environment.CurrentDirectory, path)));
PlaylistParser.Parse (new SafeUri (Path.Combine (Environment.CurrentDirectory, path)), BaseUri);
}
parser.Parse (new SafeUri ("http://download.banshee.fm/test/extended.pls"));
AssertTest (parser.Elements, false);
var parsed_playlist = PlaylistParser.Parse (new SafeUri ("http://download.banshee.fm/test/extended.pls"), BaseUri);
AssertTest (parsed_playlist.Elements, false);
}
#endregion
......
......@@ -321,6 +321,7 @@
<Compile Include="Banshee.Sources\IBatchScrobblerSource.cs" />
<Compile Include="Banshee.Playlists.Formats\PlaylistElement.cs" />
<Compile Include="Banshee.Hardware\FileSystem.cs" />
<Compile Include="Banshee.Playlists.Formats\ParsedPlaylist.cs" />
</ItemGroup>
<ItemGroup>
<EmbeddedResource Include="Banshee.Services.addin.xml">
......
......@@ -290,9 +290,9 @@ namespace Banshee.Streaming
private void LoadStreamUri(string uri)
{
try {
PlaylistParser parser = new PlaylistParser();
if (parser.Parse(new SafeUri(uri))) {
foreach (PlaylistElement element in parser.Elements) {
var parsed_playlist = PlaylistParser.Parse (new SafeUri (uri));
if (parsed_playlist != null) {
foreach (PlaylistElement element in parsed_playlist.Elements) {
if (element.Uri != null) {
// mms can be a nested link
string element_uri = element.Uri.ToString ();
......
......@@ -158,6 +158,7 @@ SOURCES = \
Banshee.Playlists.Formats/InvalidPlaylistException.cs \
Banshee.Playlists.Formats/IPlaylistFormat.cs \
Banshee.Playlists.Formats/M3uPlaylistFormat.cs \
Banshee.Playlists.Formats/ParsedPlaylist.cs \
Banshee.Playlists.Formats/PlaylistElement.cs \
Banshee.Playlists.Formats/PlaylistFormatBase.cs \
Banshee.Playlists.Formats/PlaylistFormatDescription.cs \
......
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