Initial commit of sync engine code to browser/sync....

chrome/browser/sync/util/fast_dump.h

+// Copyright (c) 2009 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.
+
+#ifndef CHROME_BROWSER_SYNC_UTIL_FAST_DUMP_H_
+#define CHROME_BROWSER_SYNC_UTIL_FAST_DUMP_H_
+
+#include <ostream>
+#include <streambuf>
+#include <string>
+
+#include "base/string_util.h"
+
+using std::ostream;
+using std::streambuf;
+using std::string;
+
+// This seems totally gratuitous, and it would be if std::ostream was fast, but
+// std::ostream is slow. It's slow because it creates a ostream::sentry (mutex)
+// for every little << operator. When you want to dump a whole lot of stuff
+// under a single mutex lock, use this FastDump class.
+namespace browser_sync {
+class FastDump {
+ public:
+  explicit FastDump(ostream* outs) : sentry_(*outs), out_(outs->rdbuf()) {
+  }
+  ostream::sentry sentry_;
+  streambuf* const out_;
+};
+}  // namespace browser_sync
+
+inline browser_sync::FastDump& operator <<
+  (browser_sync::FastDump& dump, int64 n) {
+  string numbuf(Int64ToString(n));
+  const char* number = numbuf.c_str();
+  dump.out_->sputn(number, numbuf.length());
+  return dump;
+}
+
+inline browser_sync::FastDump& operator <<
+  (browser_sync::FastDump& dump, int32 n) {
+  string numbuf(IntToString(n));
+  const char* number = numbuf.c_str();
+  dump.out_->sputn(number, numbuf.length());
+  return dump;
+}
+
+inline browser_sync::FastDump& operator <<
+  (browser_sync::FastDump& dump, const char* s) {
+  dump.out_->sputn(s, strlen(s));
+  return dump;
+}
+
+inline browser_sync::FastDump& operator <<
+  (browser_sync::FastDump& dump, const string& s) {
+  dump.out_->sputn(s.data(), s.size());
+  return dump;
+}
+
+#endif  // CHROME_BROWSER_SYNC_UTIL_FAST_DUMP_H_