1 // Copyright 2013 The Chromium Authors. All rights reserved.
2 // Use of this source code is governed by a BSD-style license that can be
3 // found in the LICENSE file.
5 // Component updates can be either differential updates or full updates.
6 // Full updates come in CRX format; differential updates come in CRX-style
7 // archives, but have a different magic number. They contain "commands.json", a
8 // list of commands for the patcher to follow. The patcher uses these commands,
9 // the other files in the archive, and the files from the existing installation
10 // of the component to create the contents of a full update, which is then
11 // installed normally.
12 // Component updates are specified by the 'codebasediff' attribute of an
13 // updatecheck response:
14 // <updatecheck codebase="http://example.com/extension_1.2.3.4.crx"
15 // hash="12345" size="9854" status="ok" version="1.2.3.4"
16 // prodversionmin="2.0.143.0"
17 // codebasediff="http://example.com/diff_1.2.3.4.crx"
18 // hashdiff="123" sizediff="101"
20 // The component updater will attempt a differential update if it is available
21 // and allowed to, and fall back to a full update if it fails.
23 // After installation (diff or full), the component updater records "fp", the
24 // fingerprint of the installed files, to later identify the existing files to
25 // the server so that a proper differential update can be provided next cycle.
28 #ifndef CHROME_BROWSER_COMPONENT_UPDATER_COMPONENT_PATCHER_H_
29 #define CHROME_BROWSER_COMPONENT_UPDATER_COMPONENT_PATCHER_H_
31 #include "base/basictypes.h"
32 #include "base/compiler_specific.h"
33 #include "chrome/browser/component_updater/component_unpacker.h"
39 class ComponentInstaller;
41 // Applies a delta patch to a single file. Specifically, creates a file at
42 // |output_file| using |input_file| patched according to the algorithm
43 // specified by |patch_type| using |patch_file|. Sets the value of error to
44 // the error code of the failing patch operation, if there is such a failure.
45 class ComponentPatcher {
47 // The type of a patch file.
54 virtual ComponentUnpacker::Error Patch(PatchType patch_type,
55 const base::FilePath& input_file,
56 const base::FilePath& patch_file,
57 const base::FilePath& output_file,
59 virtual ~ComponentPatcher() {}
62 class ComponentPatcherCrossPlatform : public ComponentPatcher {
64 ComponentPatcherCrossPlatform();
65 virtual ComponentUnpacker::Error Patch(PatchType patch_type,
66 const base::FilePath& input_file,
67 const base::FilePath& patch_file,
68 const base::FilePath& output_file,
71 DISALLOW_COPY_AND_ASSIGN(ComponentPatcherCrossPlatform);
74 // This function takes an unpacked differential CRX (|input_dir|) and a
75 // component installer, and creates a new (non-differential) unpacked CRX, which
76 // is then installed normally.
77 // The non-differential files are written into the |unpack_dir| directory.
78 // Sets |error| to the error code of the first failing patch operation.
79 ComponentUnpacker::Error DifferentialUpdatePatch(
80 const base::FilePath& input_dir,
81 const base::FilePath& unpack_dir,
82 ComponentPatcher* component_patcher,
83 ComponentInstaller* installer,
86 #endif // CHROME_BROWSER_COMPONENT_UPDATER_COMPONENT_PATCHER_H_