More memory stats code cleanup:...

base/process_util_linux.cc

 // 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.
 
 #include "base/process_util.h"
 
 #include <ctype.h>
 #include <dirent.h>
 #include <errno.h>
 #include <fcntl.h>
@@ skipping 432 matching lines @@
   // are together adding to more than one CPU's worth.
   int percentage = 100 * (cpu - last_cpu_) /
       (kHertz * TimeDelta::FromMicroseconds(time_delta).InSecondsF());
 
   last_time_ = time;
   last_cpu_ = cpu;
 
   return percentage;
 }
 
+namespace {
+
+// The format of /proc/meminfo is:
+//
+// MemTotal:      8235324 kB
+// MemFree:       1628304 kB
+// Buffers:        429596 kB
+// Cached:        4728232 kB
+// ...
+const size_t kMemTotalIndex = 1;
+const size_t kMemFreeIndex = 4;
+const size_t kMemBuffersIndex = 7;
+const size_t kMemCacheIndex = 10;
+
+}  // namespace
+
+size_t GetSystemCommitCharge() {
+  // Used memory is: total - free - buffers - caches
+  FilePath meminfo_file("/proc/meminfo");
+  std::string meminfo_data;
+  if (!file_util::ReadFileToString(meminfo_file, &meminfo_data))
+    LOG(ERROR) << "Failed to open /proc/meminfo.";

[vandebo (ex-Chrome), 2009/11/09 19:10:29]

Should this be ERROR, or just WARNING?  It doesn't seem that we should kill the
browser if /proc isn't mounted.

+    return 0;
+  std::vector<std::string> meminfo_fields;
+  SplitStringAlongWhitespace(meminfo_data, &meminfo_fields);
+
+  if (meminfo_fields.size() < kMemCacheIndex) {
+    LOG(ERROR) << "Failed to parse /proc/meminfo.  Only found " <<
+      meminfo_fields.size() << " fields.";
+    return 0;
+  }
+
+  DCHECK_EQ(meminfo_fields[kMemTotalIndex-1], "MemTotal:");
+  DCHECK_EQ(meminfo_fields[kMemFreeIndex-1], "MemFree:");
+  DCHECK_EQ(meminfo_fields[kMemBuffersIndex-1], "Buffers:");
+  DCHECK_EQ(meminfo_fields[kMemCacheIndex-1], "Cached:");
+
+  size_t result_in_kb;
+  result_in_kb = StringToInt(meminfo_fields[kMemTotalIndex]);
+  result_in_kb -= StringToInt(meminfo_fields[kMemFreeIndex]);
+  result_in_kb -= StringToInt(meminfo_fields[kMemBuffersIndex]);
+  result_in_kb -= StringToInt(meminfo_fields[kMemCacheIndex]);
+
+  return result_in_kb;
+}
+
 }  // namespace base