Adds the ability to load JSON log files to about:net-internals.

Only works with logs created by the new "--log-net-log=file",
which writes NetLog events to the specified file, regardless
of other logging command line parameters.

Using "--log-net-log" without a file name will just write
NetLog events to VLOG(1), as before.

BUG=63687
TEST=None

Review URL: http://codereview.chromium.org/6025017

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@72567 0039d316-1c4b-4281-b951-d872f2087c98

3 files changed, 35 insertions, 7 deletions

diff --git a/chrome/browser/net/chrome_net_log.cc b/chrome/browser/net/chrome_net_log.cc
index 58fe6ad..39ebe79 100644
--- a/chrome/browser/net/chrome_net_log.cc
+++ b/chrome/browser/net/chrome_net_log.cc
@@ -67,7 +67,8 @@ ChromeNetLog::ChromeNetLog()
 
   const CommandLine& command_line = *CommandLine::ForCurrentProcess();
   if (command_line.HasSwitch(switches::kLogNetLog)) {
-    net_log_logger_.reset(new NetLogLogger());
+    net_log_logger_.reset(new NetLogLogger(
+            command_line.GetSwitchValuePath(switches::kLogNetLog)));
     AddObserver(net_log_logger_.get());
   }
 }
diff --git a/chrome/browser/net/net_log_logger.cc b/chrome/browser/net/net_log_logger.cc
index bba75ca..1468e6f 100644
--- a/chrome/browser/net/net_log_logger.cc
+++ b/chrome/browser/net/net_log_logger.cc
@@ -4,11 +4,19 @@
 
 #include "chrome/browser/net/net_log_logger.h"
 
+#include <stdio.h>
+
+#include "base/file_util.h"
 #include "base/json/json_writer.h"
+#include "base/threading/thread_restrictions.h"
 #include "base/values.h"
 
-NetLogLogger::NetLogLogger()
+NetLogLogger::NetLogLogger(const FilePath &log_path)
     : ThreadSafeObserver(net::NetLog::LOG_ALL_BUT_BYTES) {
+  if (!log_path.empty()) {
+    base::ThreadRestrictions::ScopedAllowIO allow_io;
+    file_.Set(file_util::OpenFile(log_path, "w"));
+  }
 }
 
 NetLogLogger::~NetLogLogger() {}
@@ -21,8 +29,16 @@ void NetLogLogger::OnAddEntry(net::NetLog::EventType type,
   scoped_ptr<Value> value(net::NetLog::EntryToDictionaryValue(type, time,
                                                               source, phase,
                                                               params, true));
+  // Don't pretty print, so each JSON value occupies a single line, with no
+  // breaks (Line breaks in any text field will be escaped).  Using strings
+  // instead of integer identifiers allows logs from older versions to be
+  // loaded, though a little extra parsing has to be done when loading a log.
   std::string json;
-  base::JSONWriter::Write(value.get(), true, &json);
-  VLOG(1) << json;
+  base::JSONWriter::Write(value.get(), false, &json);
+  if (!file_.get()) {
+    VLOG(1) << json;
+  } else {
+    fprintf(file_.get(), "%s\n", json.c_str());
+  }
 }
 
diff --git a/chrome/browser/net/net_log_logger.h b/chrome/browser/net/net_log_logger.h
index 564f232..2cb88c6 100644
--- a/chrome/browser/net/net_log_logger.h
+++ b/chrome/browser/net/net_log_logger.h
@@ -6,14 +6,23 @@
 #define CHROME_BROWSER_NET_NET_LOG_LOGGER_H_
 #pragma once
 
+#include "base/scoped_handle.h"
 #include "chrome/browser/net/chrome_net_log.h"
 
+class FilePath;
+
 // NetLogLogger watches the NetLog event stream, and sends all entries to
-// VLOG(1).  This is to debug errors that prevent getting to the
-// about:net-internals page.
+// VLOG(1) or a path specified on creation.  This is to debug errors that
+// prevent getting to the about:net-internals page.
+//
+// Relies on ChromeNetLog only calling an Observer once at a time for
+// thread-safety.
 class NetLogLogger : public ChromeNetLog::ThreadSafeObserver {
  public:
-  NetLogLogger();
+  // If |log_path| is empty or file creation fails, writes to VLOG(1).
+  // Otherwise, writes to |log_path|.  Uses one line per entry, for
+  // easy parsing.
+  explicit NetLogLogger(const FilePath &log_path);
   ~NetLogLogger();
 
   // ThreadSafeObserver implementation:
@@ -24,6 +33,8 @@ class NetLogLogger : public ChromeNetLog::ThreadSafeObserver {
                           net::NetLog::EventParameters* params);
 
  private:
+  ScopedStdioHandle file_;
+
   DISALLOW_COPY_AND_ASSIGN(NetLogLogger);
 };