Upload UMA data using protocol buffers.

chrome/common/metrics/metrics_log_manager.cc

 // Copyright (c) 2012 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 "chrome/common/metrics/metrics_log_manager.h"
 
 #if defined(USE_SYSTEM_LIBBZ2)
 #include <bzlib.h>
 #else
 #include "third_party/bzip2/bzlib.h"
 #endif
 
 #include "base/metrics/histogram.h"
 #include "base/string_util.h"
 #include "chrome/common/metrics/metrics_log_base.h"
 
+namespace {
+
+// Used to keep track of discarded protobuf logs without having to track xml and
+// protobuf logs in separate lists.
+const char kDiscardedLog[] = "Log discarded";
+
+}  // anonymous namespace
+
 MetricsLogManager::MetricsLogManager() : max_ongoing_log_store_size_(0) {}
 
 MetricsLogManager::~MetricsLogManager() {}
 
+bool MetricsLogManager::SerializedLog::empty() const {
+  DCHECK_EQ(xml.empty(), proto.empty());
+  return xml.empty();
+}
+
 void MetricsLogManager::BeginLoggingWithLog(MetricsLogBase* log) {
   DCHECK(!current_log_.get());
   current_log_.reset(log);
 }
 
 void MetricsLogManager::StageCurrentLogForUpload() {
   DCHECK(current_log_.get());
   current_log_->CloseLog();
   staged_log_.reset(current_log_.release());
   CompressStagedLog();
 }
 
 bool MetricsLogManager::has_staged_log() const {
-  return staged_log_.get() || !compressed_staged_log_text_.empty();
+  return staged_log_.get() || !staged_log_text().empty();
+}
+
+bool MetricsLogManager::has_staged_log_proto() const {
+  return has_staged_log() && staged_log_text().proto != kDiscardedLog;
 }
 
 void MetricsLogManager::DiscardStagedLog() {
   staged_log_.reset();
-  compressed_staged_log_text_.clear();
+  staged_log_text_.xml.clear();
+  staged_log_text_.proto.clear();
+}
+
+void MetricsLogManager::DiscardStagedLogProto() {
+  staged_log_text_.proto = kDiscardedLog;
 }
 
 void MetricsLogManager::DiscardCurrentLog() {
   current_log_->CloseLog();
   current_log_.reset();
 }
 
 void MetricsLogManager::PauseCurrentLog() {
   DCHECK(!paused_log_.get());
   paused_log_.reset(current_log_.release());
 }
 
 void MetricsLogManager::ResumePausedLog() {
   DCHECK(!current_log_.get());
   current_log_.reset(paused_log_.release());
 }
 
 void MetricsLogManager::StoreStagedLogAsUnsent(LogType log_type) {
   DCHECK(has_staged_log());
+
   // If compressing the log failed, there's nothing to store.
-  if (compressed_staged_log_text_.empty())
+  if (staged_log_text().empty())
     return;
 
   if (log_type == INITIAL_LOG) {
-    unsent_initial_logs_.push_back(compressed_staged_log_text_);
+    unsent_initial_logs_.push_back(staged_log_text_);
   } else {
     // If it's too large, just note that and discard it.
     if (max_ongoing_log_store_size_ &&
-        compressed_staged_log_text_.length() > max_ongoing_log_store_size_) {
+        staged_log_text().xml.length() > max_ongoing_log_store_size_) {
+      // TODO(isherman): We probably want a similar check for protobufs, but we
+      // don't want to prevent XML upload just because the protobuf version is
+      // too long.  In practice, I'm pretty sure the XML version should always
+      // be longer, or at least on the same order of magnitude in length.
       UMA_HISTOGRAM_COUNTS(
           "UMA.Large Accumulated Log Not Persisted",
-          static_cast<int>(compressed_staged_log_text_.length()));
+          static_cast<int>(staged_log_text().xml.length()));
     } else {
-      unsent_ongoing_logs_.push_back(compressed_staged_log_text_);
+      unsent_ongoing_logs_.push_back(staged_log_text_);
     }
   }
   DiscardStagedLog();
 }
 
 void MetricsLogManager::StageNextStoredLogForUpload() {
   // Prioritize initial logs for uploading.
-  std::vector<std::string>* source_list = unsent_initial_logs_.empty() ?
-      &unsent_ongoing_logs_ : &unsent_initial_logs_;
+  std::vector<SerializedLog>* source_list =
+      unsent_initial_logs_.empty() ?
+      &unsent_ongoing_logs_ :
+      &unsent_initial_logs_;
   DCHECK(!source_list->empty());
-  DCHECK(compressed_staged_log_text_.empty());
-  compressed_staged_log_text_ = source_list->back();
+  DCHECK(staged_log_text().empty());
+  staged_log_text_ = source_list->back();
   source_list->pop_back();
 }
 
 void MetricsLogManager::PersistUnsentLogs() {
   DCHECK(log_serializer_.get());
   if (!log_serializer_.get())
     return;
   log_serializer_->SerializeLogs(unsent_initial_logs_, INITIAL_LOG);
   log_serializer_->SerializeLogs(unsent_ongoing_logs_, ONGOING_LOG);
 }
 
 void MetricsLogManager::LoadPersistedUnsentLogs() {
   DCHECK(log_serializer_.get());
   if (!log_serializer_.get())
     return;
   log_serializer_->DeserializeLogs(INITIAL_LOG, &unsent_initial_logs_);
   log_serializer_->DeserializeLogs(ONGOING_LOG, &unsent_ongoing_logs_);
 }
 
 void MetricsLogManager::CompressStagedLog() {
-  int text_size = staged_log_->GetEncodedLogSize();
+  int text_size = staged_log_->GetEncodedLogSizeXml();
   std::string staged_log_text;
   DCHECK_GT(text_size, 0);
-  staged_log_->GetEncodedLog(WriteInto(&staged_log_text, text_size + 1),
-                             text_size);
+  staged_log_->GetEncodedLogXml(WriteInto(&staged_log_text, text_size + 1),
+                                text_size);
 
-  bool success = Bzip2Compress(staged_log_text, &compressed_staged_log_text_);
+  bool success = Bzip2Compress(staged_log_text, &staged_log_text_.xml);
   if (success) {
     // Allow security-conscious users to see all metrics logs that we send.
     DVLOG(1) << "METRICS LOG: " << staged_log_text;
+
+    // Note that we only save the protobuf version if we succeeded in
+    // compressing the XML, so that the two data streams are the same.
+    staged_log_->GetEncodedLogProto(&staged_log_text_.proto);
   } else {
     NOTREACHED() << "Failed to compress log for transmission.";
   }
 }
 
 // static
 // This implementation is based on the Firefox MetricsService implementation.
 bool MetricsLogManager::Bzip2Compress(const std::string& input,
                                       std::string* output) {
   bz_stream stream = {0};
@@ skipping 27 matching lines @@
     // TODO(jar): See if it would be better to do a CHECK() here.
     return false;
   }
   result = BZ2_bzCompressEnd(&stream);
   DCHECK(result == BZ_OK);
 
   output->resize(stream.total_out_lo32);
 
   return true;
 }