Get rid of device/host clock synchronization in android_commands.py.

tools/android/md5sum/md5sum.cc

+// Copyright (c) 2012 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.
+
+// Md5sum implementation for Android. This version handles files as well as
+// directories. Its output is sorted by file path.
+
+#include <fstream>
+#include <iostream>
+#include <set>
+#include <string>
+
+#include "base/file_path.h"
+#include "base/file_util.h"
+#include "base/logging.h"
+#include "base/md5.h"
+
+namespace {
+
+// Returns whether |path|'s MD5 was successfully written to |digest_string|.
+bool MD5Sum(const char* path, std::string* digest_string) {
+  std::ifstream stream(path);
+  if (!stream.good()) {
+    LOG(ERROR) << "Could not open file " << path;
+    return false;
+  }
+  base::MD5Context ctx;
+  base::MD5Init(&ctx);
+  char buf[1024];
+  while (stream.good()) {
+    std::streamsize bytes_read = stream.readsome(buf, sizeof(buf));
+    if (bytes_read == 0)
+      break;
+    base::MD5Update(&ctx, base::StringPiece(buf, bytes_read));
+  }
+  if (stream.fail()) {
+    LOG(ERROR) << "Error reading file " << path;
+    return false;
+  }
+  base::MD5Digest digest;
+  base::MD5Final(&digest, &ctx);
+  *digest_string = base::MD5DigestToBase16(digest);
+  return true;
+}
+
+// Returns the set of all files contained in |files|. This handles directories
+// by walking them recursively.
+std::set<std::string> MakeFileSet(const char** files) {
+  std::set<std::string> file_set;
+  for (const char** file = files; *file; ++file) {
+    FilePath file_path(*file);
+    if (file_util::DirectoryExists(file_path)) {
+      file_util::FileEnumerator file_enumerator(
+          file_path, true /* recurse */, file_util::FileEnumerator::FILES);
+      for (FilePath child, empty; (child = file_enumerator.Next()) != empty; ) {
+        file_util::AbsolutePath(&child);
+        file_set.insert(child.value());
+      }
+    } else {
+      file_set.insert(*file);
+    }
+  }
+  return file_set;
+}
+
+}  // namespace
+
+int main(int argc, const char* argv[]) {
+  if (argc < 2) {
+    LOG(ERROR) << "Usage: md5sum <path/to/file_or_dir>...";
+    return 1;
+  }
+  const std::set<std::string> files = MakeFileSet(argv + 1);
+  bool failed = false;
+  std::string digest;
+  for (std::set<std::string>::const_iterator it = files.begin();
+       it != files.end(); ++it) {
+    if (!MD5Sum(it->c_str(), &digest))
+      failed = true;
+    FilePath file_path(*it);
+    file_util::AbsolutePath(&file_path);
+    std::cout << digest << "  " << file_path.value() << std::endl;
+  }
+  return failed;
+}