Port parts of base/process_util to Linux.

base/process_util_linux.cc

+// Copyright (c) 2008 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 "base/process_util.h"
+
+#include <string>
+
+#include "base/file_util.h"
+#include "base/logging.h"
+#include "base/string_tokenizer.h"
+#include "base/string_util.h"
+
+namespace {
+
+enum ParsingState {
+  KEY_NAME,
+  KEY_VALUE
+};
+
+}  // namespace
+
+namespace process_util {
+
+// To have /proc/self/io file you must enable CONFIG_TASK_IO_ACCOUNTING
+// in your kernel configuration.
+bool ProcessMetrics::GetIOCounters(IoCounters* io_counters) {
+  std::string proc_io_contents;
+  if (!file_util::ReadFileToString(L"/proc/self/io", &proc_io_contents))
+    return false;
+
+  (*io_counters).OtherOperationCount = 0;
+  (*io_counters).OtherTransferCount = 0;
+
+  StringTokenizer tokenizer(proc_io_contents, ": \n");
+  ParsingState state = KEY_NAME;
+  std::string last_key_name;
+  while (tokenizer.GetNext()) {
+    switch (state) {
+      case KEY_NAME:
+        last_key_name = tokenizer.token();
+        state = KEY_VALUE;
+        break;
+      case KEY_VALUE:
+        DCHECK(!last_key_name.empty());
+        if (last_key_name == "syscr") {

[Evan Stade, 2008/10/13 22:28:11]

maybe pull these string literals out and store them in const char*s

+          (*io_counters).ReadOperationCount = StringToInt64(tokenizer.token());
+        } else if (last_key_name == "syscw") {
+          (*io_counters).WriteOperationCount = StringToInt64(tokenizer.token());
+        } else if (last_key_name == "rchar") {
+          (*io_counters).ReadTransferCount = StringToInt64(tokenizer.token());
+        } else if (last_key_name == "wchar") {
+          (*io_counters).WriteTransferCount = StringToInt64(tokenizer.token());
+        }
+        state = KEY_NAME;
+        break;
+    }
+  }
+  return true;
+}
+
+}  // namespace process_util