Add DiskInfo struct and functions.

base/process/process_metrics.h

 // 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.
 
 // This file contains routines for gathering resource statistics for processes
 // running on the system.
 
 #ifndef BASE_PROCESS_PROCESS_METRICS_H_
 #define BASE_PROCESS_PROCESS_METRICS_H_
 
 #include <string>
 
 #include "base/base_export.h"
 #include "base/basictypes.h"
+#include "base/gtest_prod_util.h"
 #include "base/process/process_handle.h"
 #include "base/time/time.h"
 
 #if defined(OS_MACOSX)
 #include <mach/mach.h>
 #endif
 
 namespace base {
 
 #if defined(OS_WIN)
@@ skipping 229 matching lines @@
 
   // Gem data will be -1 if not supported.
   int gem_objects;
   long long gem_size;
 };
 
 // Retrieves data from /proc/meminfo about system-wide memory consumption.
 // Fills in the provided |meminfo| structure. Returns true on success.
 // Exposed for memory debugging widget.
 BASE_EXPORT bool GetSystemMemoryInfo(SystemMemoryInfoKB* meminfo);
+
+// Data from /proc/diskstats about system-wide disk I/O.
+struct BASE_EXPORT SystemDiskInfo {
+  SystemDiskInfo();
+
+  uint64 reads;
+  uint64 reads_merged;
+  uint64 sectors_read;
+  uint64 read_time;
+  uint64 writes;
+  uint64 writes_merged;
+  uint64 sectors_written;
+  uint64 write_time;
+  uint64 io;
+  uint64 io_time;
+  uint64 weighted_io_time;
+};
+
+// Checks whether the candidate string is a valid disk name, [sh]d[a-z]+
+// for a generic disk or mmcblk[0-9]+ for the MMC case.
+// Names of disk partitions (e.g. sda1) are not valid.
+BASE_EXPORT bool IsValidDiskName(const std::string& candidate);
+
+// Retrieves data from /proc/diskstats about system-wide disk I/O.
+// Fills in the provided |diskinfo| structure. Returns true on success.
+BASE_EXPORT bool GetSystemDiskInfo(SystemDiskInfo* diskinfo);
 #endif  // defined(OS_LINUX) || defined(OS_ANDROID)
 
 #if defined(OS_CHROMEOS)
 // Data from files in directory /sys/block/zram0 about ZRAM usage.
 struct BASE_EXPORT SwapInfo {
   SwapInfo()
       : num_reads(0),
         num_writes(0),
         compr_data_size(0),
         orig_data_size(0),
@@ skipping 15 matching lines @@
 // Collects and holds performance metrics for system memory and disk.
 // Provides functionality to retrieve the data on various platforms and
 // to serialize the stored data.
 class SystemMetrics {
  public:
   SystemMetrics() : committed_memory_(0) { }
 
   static SystemMetrics Sample();
 
  private:
+  FRIEND_TEST_ALL_PREFIXES(SystemMetricsTest, SystemMetrics);
+
   size_t committed_memory_;
 #if defined(OS_LINUX) || defined(OS_ANDROID)
   SystemMemoryInfoKB memory_info_;
 #endif
 };
 
 }  // namespace base
 
 #endif  // BASE_PROCESS_PROCESS_METRICS_H_