[gnome-ostree] build: Add zdisks task

[Colin Walters <walters src gnome org>]

commit 44d399704338a1351befbe29e9a5c146215a625f
Author: Colin Walters <walters verbum org>
Date:   Sun Mar 3 18:23:46 2013 -0500

    build: Add zdisks task
    
    So it's relatively efficient to download.

 Makefile-ostbuild.am        |    1 +
 src/js/tasks/task-zdisks.js |  115 +++++++++++++++++++++++++++++++++++++++++++
 2 files changed, 116 insertions(+), 0 deletions(-)
---
diff --git a/Makefile-ostbuild.am b/Makefile-ostbuild.am
index 033413c..948b099 100644
--- a/Makefile-ostbuild.am
+++ b/Makefile-ostbuild.am
@@ -75,6 +75,7 @@ jsosttasks_DATA= \
        src/js/tasks/task-bdiff.js \
        src/js/tasks/task-builddisks.js \
        src/js/tasks/task-smoketest.js \
+       src/js/tasks/task-zdisks.js \
        $(NULL)
 
 endif
diff --git a/src/js/tasks/task-zdisks.js b/src/js/tasks/task-zdisks.js
new file mode 100644
index 0000000..4cd6cec
--- /dev/null
+++ b/src/js/tasks/task-zdisks.js
@@ -0,0 +1,115 @@
+// -*- indent-tabs-mode: nil; tab-width: 2; -*-
+// Copyright (C) 2013 Colin Walters <walters verbum org>
+//
+// This library is free software; you can redistribute it and/or
+// modify it under the terms of the GNU Lesser General Public
+// License as published by the Free Software Foundation; either
+// version 2 of the License, or (at your option) any later version.
+//
+// This library is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+// Lesser General Public License for more details.
+//
+// You should have received a copy of the GNU Lesser General Public
+// License along with this library; if not, write to the
+// Free Software Foundation, Inc., 59 Temple Place - Suite 330,
+// Boston, MA 02111-1307, USA.
+
+const GLib = imports.gi.GLib;
+const Gio = imports.gi.Gio;
+const Lang = imports.lang;
+const Format = imports.format;
+
+const GSystem = imports.gi.GSystem;
+
+const Builtin = imports.builtin;
+const ArgParse = imports.argparse;
+const Task = imports.task;
+const ProcUtil = imports.procutil;
+const BuildUtil = imports.buildutil;
+const LibQA = imports.libqa;
+const JsonDB = imports.jsondb;
+const JsonUtil = imports.jsonutil;
+const JSUtil = imports.jsutil;
+const GuestFish = imports.guestfish;
+
+const TaskZDisks = new Lang.Class({
+    Name: 'TaskZDisks',
+    Extends: Task.TaskDef,
+
+    TaskName: "zdisks",
+    TaskAfter: ['builddisks'],
+
+    // Legacy
+    _VERSION_RE: /^(\d+)\.(\d+)$/,
+
+    execute: function(cancellable) {
+        let subworkdir = Gio.File.new_for_path('.');
+
+             let baseImageDir = this.workdir.resolve_relative_path('images/z');
+        GSystem.file_ensure_directory(baseImageDir, true, cancellable);
+             let currentImageLink = baseImageDir.get_child('current');
+
+             let sourceImageDir = this.workdir.get_child('images');
+        let sourceCurrent = sourceImageDir.get_child('current');
+        let sourceRevision = sourceCurrent.query_info('standard::symlink-target',
+                                                      Gio.FileQueryInfoFlags.NOFOLLOW_SYMLINKS,
+                                                      cancellable).get_symlink_target();
+        let targetImageDir = baseImageDir.get_child(sourceRevision);
+        if (targetImageDir.query_exists(null)) {
+            print("Already created " + targetImageDir.get_path());
+            return;
+        }
+
+        let workImageDir = subworkdir.get_child('images');
+        GSystem.file_ensure_directory(workImageDir, true, cancellable);
+
+        let e = sourceCurrent.enumerate_children('standard::*', Gio.FileQueryInfoFlags.NOFOLLOW_SYMLINKS,
+                                                 cancellable);
+        let info;
+             while ((info = e.next_file(cancellable)) != null) {
+                 let name = info.get_name();
+            if (!JSUtil.stringEndswith(name, '.qcow2'))
+                continue;
+            let inPath = e.get_child(info);
+            let outPath = workImageDir.get_child(name + '.gz');
+            let outStream = outPath.create(Gio.FileCreateFlags.REPLACE_DESTINATION, cancellable);
+            let compressor = Gio.ZlibCompressor.new(Gio.ZlibCompressorFormat.GZIP, 7);
+            let outConverter = Gio.ConverterOutputStream.new(outStream, compressor);
+            let inStream = inPath.read(cancellable);
+            outConverter.splice(inStream, Gio.OutputStreamSpliceFlags.CLOSE_SOURCE | 
+                                Gio.OutputStreamSpliceFlags.CLOSE_TARGET, cancellable);
+        }
+
+        GSystem.file_rename(workImageDir, targetImageDir, cancellable);
+
+        BuildUtil.atomicSymlinkSwap(currentImageLink, targetImageDir, cancellable);
+
+        this._cleanOldVersions(baseImageDir, 1, cancellable);
+    },
+
+    _loadVersionsFrom: function(dir, cancellable) {
+             let e = dir.enumerate_children('standard::*', Gio.FileQueryInfoFlags.NOFOLLOW_SYMLINKS, 
cancellable);
+             let info;
+             let results = [];
+             while ((info = e.next_file(cancellable)) != null) {
+                 let name = info.get_name();
+                 let match = this._VERSION_RE.exec(name);
+                 if (!match)
+                           continue;
+                 results.push(name);
+             }
+             results.sort(BuildUtil.compareVersions);
+             return results;
+    },
+
+    _cleanOldVersions: function(dir, retain, cancellable) {
+             let versions = this._loadVersionsFrom(dir, cancellable);
+             while (versions.length > retain) {
+                 let child = dir.get_child(versions.shift());
+                 GSystem.shutil_rm_rf(child, cancellable);
+             }
+    },
+
+});