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. 4 5 #ifndef CHROME_INSTALLER_SETUP_ARCHIVE_PATCH_HELPER_H_ 6 #define CHROME_INSTALLER_SETUP_ARCHIVE_PATCH_HELPER_H_ 7 8 #include "base/basictypes.h" 9 #include "base/files/file_path.h" 10 11 namespace installer { 12 13 // A helper class that facilitates uncompressing and patching the chrome archive 14 // and installer. 15 // 16 // Chrome's installer is deployed along with a compressed archive containing 17 // either 1) an uncompressd archive of the product binaries or 2) a patch file 18 // to be applied to the uncompressed archive of the version being updated. To 19 // obtain the uncompressed archive, the contents of the compressed archive are 20 // uncompressed and extracted. Installation proceeds directly if the 21 // uncompressed archive is found after this step. Otherwise, the patch is 22 // applied to the previous version's uncompressed archive using either 23 // Courgette's ensemble patching or bspatch. 24 // 25 // Chrome's installer itself may also be deployed as a patch against the 26 // previous version's saved installer binary. The same process is followed to 27 // obtain the new installer. The compressed archive unconditionally contains a 28 // patch file in this case. 29 class ArchivePatchHelper { 30 public: 31 // Constructs an instance that can uncompress |compressed_archive| into 32 // |working_directory| and optionally apply the extracted patch file to 33 // |patch_source|, writing the result to |target|. 34 ArchivePatchHelper(const base::FilePath& working_directory, 35 const base::FilePath& compressed_archive, 36 const base::FilePath& patch_source, 37 const base::FilePath& target); 38 39 ~ArchivePatchHelper(); 40 41 // Uncompresses |compressed_archive| in |working_directory| then applies the 42 // extracted patch file to |patch_source|, writing the result to |target|. 43 // Ensemble patching via Courgette is attempted first. If that fails, bspatch 44 // is attempted. Returns false if uncompression or both patching steps fail. 45 static bool UncompressAndPatch(const base::FilePath& working_directory, 46 const base::FilePath& compressed_archive, 47 const base::FilePath& patch_source, 48 const base::FilePath& target); 49 50 // Uncompresses compressed_archive() into the working directory. On success, 51 // last_uncompressed_file (if not NULL) is populated with the path to the last 52 // file extracted from the archive. 53 bool Uncompress(base::FilePath* last_uncompressed_file); 54 55 // Attempts to use courgette to apply last_uncompressed_file() to 56 // patch_source() to generate target(). Returns false if patching fails. 57 bool EnsemblePatch(); 58 59 // Attempts to use bspatch to apply last_uncompressed_file() to patch_source() 60 // to generate target(). Returns false if patching fails. 61 bool BinaryPatch(); 62 63 const base::FilePath& compressed_archive() const { 64 return compressed_archive_; 65 } 66 void set_patch_source(const base::FilePath& patch_source) { 67 patch_source_ = patch_source; 68 } 69 const base::FilePath& patch_source() const { 70 return patch_source_; 71 } 72 const base::FilePath& target() const { 73 return target_; 74 } 75 76 // Returns the path of the last file extracted by Uncompress(). 77 const base::FilePath& last_uncompressed_file() const { 78 return last_uncompressed_file_; 79 } 80 void set_last_uncompressed_file( 81 const base::FilePath& last_uncompressed_file) { 82 last_uncompressed_file_ = last_uncompressed_file; 83 } 84 85 private: 86 base::FilePath working_directory_; 87 base::FilePath compressed_archive_; 88 base::FilePath patch_source_; 89 base::FilePath target_; 90 base::FilePath last_uncompressed_file_; 91 92 DISALLOW_COPY_AND_ASSIGN(ArchivePatchHelper); 93 }; 94 95 } // namespace installer 96 97 #endif // CHROME_INSTALLER_SETUP_ARCHIVE_PATCH_HELPER_H_ 98
