Differential updates for components.

chrome/browser/component_updater/component_patcher_win.cc

+// Copyright (c) 2013 The Chromium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#include "chrome/browser/component_updater/component_patcher_win.h"
+
+#include <string>
+
+#include "base/base_paths.h"
+#include "base/command_line.h"
+#include "base/file_util.h"
+#include "base/path_service.h"
+#include "base/process_util.h"
+#include "base/string_util.h"
+#include "chrome/installer/util/util_constants.h"
+
+namespace {
+
+std::string PatchTypeToCommandLineSwitch(PatchType patch_type) {
+  if (patch_type == PATCH_TYPE_COURGETTE) {
+    return std::string(installer::switches::kCourgette);
+  } else if (patch_type == PATCH_TYPE_BSDIFF) {
+    return std::string(installer::switches::kBsdiff);
+  } else {
+    return std::string();
+  }
+}
+
+// Finds the path to the setup.exe. First, it looks for the program in the
+// "installer" directory. If the program is not found there, it tries to find it
+// in the directory where chrome.dll. Returns the path to the setup.exe, if the
+// path exists, otherwise it returns an an empty path.
+base::FilePath FindSetupProgram() {
+  base::FilePath exe_dir;
+  if (!PathService::Get(base::DIR_MODULE, &exe_dir))
+    return base::FilePath();
+
+  const std::string installer_dir(WideToASCII(installer::kInstallerDir));
+  const std::string setup_exe(WideToASCII(installer::kSetupExe));
+
+  base::FilePath setup_path = exe_dir;
+  setup_path = setup_path.AppendASCII(installer_dir);
+  setup_path = setup_path.AppendASCII(setup_exe);
+  if (file_util::PathExists(setup_path))
+    return setup_path;
+
+  setup_path = exe_dir;
+  setup_path = setup_path.AppendASCII(setup_exe);
+  if (file_util::PathExists(setup_path))
+    return setup_path;
+
+  return base::FilePath();
+}
+
+}  // namespace
+
+// Applies the patch to the input file. Returns DELTA_OK if the pacth was
+// successfully applied, DELTA_OPERATION_FAILURE if the patch operation
+// encountered errors, and DELTA_PATCH_PROCESS_FAILURE if there was an error
+// when running the patch code out of process. In the error case, detailed error
+// information could be returned in the error parameter.
+DeltaUpdateResult ComponentPatcherWin::Patch(PatchType patch_type,
+                                const base::FilePath& input_file,
+                                const base::FilePath& patch_file,
+                                const base::FilePath& output_file,
+                                int* error) {
+    *error = 0;
+
+    const base::FilePath exe_path = FindSetupProgram();
+    if (exe_path.empty()) {
+      return DELTA_PATCH_PROCESS_FAILURE;
+    }
+
+    const std::string patch_type_str(PatchTypeToCommandLineSwitch(patch_type));
+
+    CommandLine cl(CommandLine::NO_PROGRAM);
+    cl.AppendSwitchASCII(installer::switches::kPatch, patch_type_str.c_str());
+    cl.AppendSwitchPath(installer::switches::kInputFile, input_file);
+    cl.AppendSwitchPath(installer::switches::kPatchFile, patch_file);
+    cl.AppendSwitchPath(installer::switches::kOutputFile, output_file);
+
+    base::LaunchOptions launch_options;
+    launch_options.wait = true;
+    launch_options.start_hidden = true;
+    CommandLine setup_path(exe_path);
+    setup_path.AppendArguments(cl, false);
+
+    base::ProcessHandle ph;
+    int exit_code = 0;
+    if (!base::LaunchProcess(setup_path, launch_options, &ph) ||
+        !base::WaitForExitCode(ph, &exit_code)) {
+      return DELTA_PATCH_PROCESS_FAILURE;
+    }
+
+    *error = exit_code;
+    return *error ? DELTA_OPERATION_FAILURE : DELTA_OK;
+}
+