Support using UMA_HISTOGRAM_CUSTOM_ENUMERATION from the renderer.

base/metrics/histogram.cc

 // Copyright (c) 2011 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.
 
 // Histogram is an object that aggregates statistics, and can summarize them in
 // various forms, including ASCII graphical, HTML, and numerically (as a
 // vector of numbers corresponding to each of the aggregating buckets).
 // See header file for details and examples.
 
 #include "base/metrics/histogram.h"
@@ skipping 221 matching lines @@
   Pickle pickle;
   pickle.WriteString(histogram.histogram_name());
   pickle.WriteInt(histogram.declared_min());
   pickle.WriteInt(histogram.declared_max());
   pickle.WriteSize(histogram.bucket_count());
   pickle.WriteUInt32(histogram.range_checksum());
   pickle.WriteInt(histogram.histogram_type());
   pickle.WriteInt(histogram.flags());
 
   snapshot.Serialize(&pickle);
+
+  histogram.SerializeRanges(&pickle);
+
   return std::string(static_cast<const char*>(pickle.data()), pickle.size());
 }
 
 // static
 bool Histogram::DeserializeHistogramInfo(const std::string& histogram_info) {
   if (histogram_info.empty()) {
-      return false;
+    return false;
   }
 
   Pickle pickle(histogram_info.data(),
                 static_cast<int>(histogram_info.size()));
   std::string histogram_name;
   int declared_min;
   int declared_max;
   size_t bucket_count;
   uint32 range_checksum;
   int histogram_type;
   int pickle_flags;
   SampleSet sample;
 
   void* iter = NULL;
   if (!pickle.ReadString(&iter, &histogram_name) ||
       !pickle.ReadInt(&iter, &declared_min) ||
       !pickle.ReadInt(&iter, &declared_max) ||
       !pickle.ReadSize(&iter, &bucket_count) ||
       !pickle.ReadUInt32(&iter, &range_checksum) ||
       !pickle.ReadInt(&iter, &histogram_type) ||
       !pickle.ReadInt(&iter, &pickle_flags) ||
       !sample.Histogram::SampleSet::Deserialize(&iter, pickle)) {
     DLOG(ERROR) << "Pickle error decoding Histogram: " << histogram_name;
     return false;
   }
+
   DCHECK(pickle_flags & kIPCSerializationSourceFlag);
   // Since these fields may have come from an untrusted renderer, do additional
   // checks above and beyond those in Histogram::Initialize()
   if (declared_max <= 0 || declared_min <= 0 || declared_max < declared_min ||
       INT_MAX / sizeof(Count) <= bucket_count || bucket_count < 2) {
     DLOG(ERROR) << "Values error decoding Histogram: " << histogram_name;
     return false;
   }
 
   Flags flags = static_cast<Flags>(pickle_flags & ~kIPCSerializationSourceFlag);
 
   DCHECK_NE(NOT_VALID_IN_RENDERER, histogram_type);
 
   Histogram* render_histogram(NULL);
 
   if (histogram_type == HISTOGRAM) {
     render_histogram = Histogram::FactoryGet(
         histogram_name, declared_min, declared_max, bucket_count, flags);
   } else if (histogram_type == LINEAR_HISTOGRAM) {
     render_histogram = LinearHistogram::FactoryGet(
         histogram_name, declared_min, declared_max, bucket_count, flags);
   } else if (histogram_type == BOOLEAN_HISTOGRAM) {
     render_histogram = BooleanHistogram::FactoryGet(histogram_name, flags);
+  } else if (histogram_type == CUSTOM_HISTOGRAM) {
+    std::vector<Histogram::Sample> sample_ranges(bucket_count);
+    if (!CustomHistogram::DeserializeRanges(&iter, pickle, &sample_ranges)) {
+      DLOG(ERROR) << "Pickle error decoding ranges: " << histogram_name;
+      return false;
+    }
+    render_histogram =
+        CustomHistogram::FactoryGet(histogram_name, sample_ranges, flags);
   } else {
     DLOG(ERROR) << "Error Deserializing Histogram Unknown histogram_type: "
                 << histogram_type;
     return false;
   }
 
   DCHECK_EQ(render_histogram->declared_min(), declared_min);
   DCHECK_EQ(render_histogram->declared_max(), declared_max);
   DCHECK_EQ(render_histogram->bucket_count(), bucket_count);
   DCHECK_EQ(render_histogram->range_checksum(), range_checksum);
@@ skipping 126 matching lines @@
   if (StatisticsRecorder::dump_on_exit()) {
     std::string output;
     WriteAscii(true, "\n", &output);
     DLOG(INFO) << output;
   }
 
   // Just to make sure most derived class did this properly...
   DCHECK(ValidateBucketRanges());
 }
 
+bool Histogram::SerializeRanges(Pickle* pickle) const {
+  return true;
+}
+
 // Calculate what range of values are held in each bucket.
 // We have to be careful that we don't pick a ratio between starting points in
 // consecutive buckets that is sooo small, that the integer bounds are the same
 // (effectively making one bucket get no values).  We need to avoid:
 //   ranges(i) == ranges(i + 1)
 // To avoid that, we just do a fine-grained bucket width as far as we need to
 // until we get a ratio that moves us along at least 2 units at a time.  From
 // that bucket onward we do use the exponential growth of buckets.
 void Histogram::InitializeBucketRange() {
   double log_max = log(static_cast<double>(declared_max()));
@@ skipping 521 matching lines @@
 }
 
 CustomHistogram::CustomHistogram(const std::string& name,
                                  const std::vector<Sample>& custom_ranges)
     : Histogram(name, custom_ranges[1], custom_ranges.back(),
                 custom_ranges.size()) {
   DCHECK_GT(custom_ranges.size(), 1u);
   DCHECK_EQ(custom_ranges[0], 0);
 }
 
+bool CustomHistogram::SerializeRanges(Pickle* pickle) const {
+  for (size_t i = 0; i < cached_ranges()->size(); ++i) {
+    if (!pickle->WriteInt(cached_ranges()->ranges(i)))
+      return false;
+  }
+  return true;
+}
+
+// static
+bool CustomHistogram::DeserializeRanges(
+    void** iter, const Pickle& pickle, std::vector<Histogram::Sample>* ranges) {
+  for (size_t i = 0; i < ranges->size(); ++i) {
+    if (!pickle.ReadInt(iter, &(*ranges)[i]))
+      return false;
+  }
+  return true;
+}
+
 void CustomHistogram::InitializedCustomBucketRange(
     const std::vector<Sample>& custom_ranges) {
   DCHECK_GT(custom_ranges.size(), 1u);
   DCHECK_EQ(custom_ranges[0], 0);
   DCHECK_LE(custom_ranges.size(), bucket_count());
   for (size_t index = 0; index < custom_ranges.size(); ++index)
     SetBucketRange(index, custom_ranges[index]);
   ResetRangeChecksum();
 }
 
@@ skipping 288 matching lines @@
 
 // static
 StatisticsRecorder::HistogramMap* StatisticsRecorder::histograms_ = NULL;
 // static
 StatisticsRecorder::RangesMap* StatisticsRecorder::ranges_ = NULL;
 // static
 base::Lock* StatisticsRecorder::lock_ = NULL;
 // static
 bool StatisticsRecorder::dump_on_exit_ = false;
 }  // namespace base