[NOT TO COMMIT YET] Using proc/pid/status file contents to get process metrics in linux.

base/process/process_metrics_linux.cc

Index: base/process/process_metrics_linux.cc
diff --git a/base/process/process_metrics_linux.cc b/base/process/process_metrics_linux.cc
index adca7c5ee23bd53914342cffd2aab166402fe920..375b9fbe6cf08b61187451c9e9a0df71e63e8cd9 100644
--- a/base/process/process_metrics_linux.cc
+++ b/base/process/process_metrics_linux.cc
@@ -59,30 +59,9 @@ size_t ReadProcStatusAndGetFieldAsSizeT(pid_t pid, const std::string& field) {
     if (!ReadFileToString(stat_file, &status))
       return 0;
   }
-
-  StringPairs pairs;
-  SplitStringIntoKeyValuePairs(status, ':', '\n', &pairs);
-  TrimKeyValuePairs(&pairs);
-  for (size_t i = 0; i < pairs.size(); ++i) {
-    const std::string& key = pairs[i].first;
-    const std::string& value_str = pairs[i].second;
-    if (key == field) {
-      std::vector<StringPiece> split_value_str = SplitStringPiece(
-          value_str, " ", base::TRIM_WHITESPACE, base::SPLIT_WANT_ALL);
-      if (split_value_str.size() != 2 || split_value_str[1] != "kB") {
-        NOTREACHED();
-        return 0;
-      }
-      size_t value;
-      if (!StringToSizeT(split_value_str[0], &value)) {
-        NOTREACHED();
-        return 0;
-      }
-      return value;
-    }
-  }
-  NOTREACHED();
-  return 0;
+  size_t value;
+  CHECK(ParseProcStatusAndGetField(status, field, &value));

[Lei Zhang, 2015/10/07 16:10:54]

CHECK() is a bit strong. Any project that uses this code will crash if a
/proc/<pid>/status file is ever malformed.

[ssid, 2015/10/07 17:11:34]

Sorry I beleived NOTREACHED was CHECK. Just realized it is DCHECK. fixed it.

+  return value;
 }
 
 #if defined(OS_LINUX)
@@ -432,6 +411,31 @@ int ParseProcStatCPU(const std::string& input) {
   return -1;
 }
 
+bool ParseProcStatusAndGetField(const std::string& proc_status_contents,
+                                const std::string& field,
+                                size_t* value) {
+  StringPairs pairs;
+  SplitStringIntoKeyValuePairs(proc_status_contents, ':', '\n', &pairs);
+  TrimKeyValuePairs(&pairs);
+  for (size_t i = 0; i < pairs.size(); ++i) {
+    const std::string& key = pairs[i].first;
+    const std::string& value_str = pairs[i].second;
+    if (key == field) {
+      std::vector<StringPiece> split_value_str = SplitStringPiece(
+          value_str, " ", base::TRIM_WHITESPACE, base::SPLIT_WANT_ALL);
+      if (split_value_str.size() != 2 || split_value_str[1] != "kB") {
+        return false;
+      }
+      if (StringToSizeT(split_value_str[0], value)) {
+        *value *= 1024;
+        return true;
+      }
+      return false;
+    }
+  }
+  return false;
+}
+
 const char kProcSelfExe[] = "/proc/self/exe";
 
 int GetNumberOfThreads(ProcessHandle process) {