Implement write methods for SparseHistogram

Implementation based on existing methods in Histogram.

BUG=


Review URL: https://chromiumcodereview.appspot.com/13469020

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@192636 0039d316-1c4b-4281-b951-d872f2087c98

base/metrics/histogram.cc

@@ -340,12 +340,7 @@ double Histogram::GetBucketSize(Count current, size_t i) const {
 }
 
 const string Histogram::GetAsciiBucketRange(size_t i) const {
-  string result;
-  if (kHexRangePrintingFlag & flags())
-    StringAppendF(&result, "%#x", ranges(i));
-  else
-    StringAppendF(&result, "%d", ranges(i));
-  return result;
+  return GetSimpleAsciiBucketRange(ranges(i));
 }
 
 //------------------------------------------------------------------------------
@@ -490,27 +485,6 @@ void Histogram::WriteAsciiBucketContext(const int64 past,
   }
 }
 
-void Histogram::WriteAsciiBucketValue(Count current,
-                                      double scaled_sum,
-                                      string* output) const {
-  StringAppendF(output, " (%d = %3.1f%%)", current, current/scaled_sum);
-}
-
-void Histogram::WriteAsciiBucketGraph(double current_size,
-                                      double max_size,
-                                      string* output) const {
-  const int k_line_length = 72;  // Maximal horizontal width of graph.
-  int x_count = static_cast<int>(k_line_length * (current_size / max_size)
-                                 + 0.5);
-  int x_remainder = k_line_length - x_count;
-
-  while (0 < x_count--)
-    output->append("-");
-  output->append("O");
-  while (0 < x_remainder--)
-    output->append(" ");
-}
-
 void Histogram::GetParameters(DictionaryValue* params) const {
   params->SetString("type", HistogramTypeToString(GetHistogramType()));
   params->SetInteger("min", declared_min());

base/metrics/histogram.h

@@ -511,15 +511,6 @@ class BASE_EXPORT Histogram : public HistogramBase {
                                const int64 remaining, const size_t i,
                                std::string* output) const;
 
-  // Write textual description of the bucket contents (relative to histogram).
-  // Output is the count in the buckets, as well as the percentage.
-  void WriteAsciiBucketValue(Count current, double scaled_sum,
-                             std::string* output) const;
-
-  // Produce actual graph (set of blank vs non blank char's) for a bucket.
-  void WriteAsciiBucketGraph(double current_size, double max_size,
-                             std::string* output) const;
-
   // WriteJSON calls these.
   virtual void GetParameters(DictionaryValue* params) const OVERRIDE;
 

base/metrics/histogram_base.cc

@@ -14,6 +14,7 @@
 #include "base/metrics/sparse_histogram.h"
 #include "base/pickle.h"
 #include "base/process_util.h"
+#include "base/stringprintf.h"
 #include "base/values.h"
 
 namespace base {
@@ -124,4 +125,35 @@ void HistogramBase::WriteJSON(std::string* output) const {
   serializer.Serialize(root);
 }
 
+void HistogramBase::WriteAsciiBucketGraph(double current_size,
+                                          double max_size,
+                                          std::string* output) const {
+  const int k_line_length = 72;  // Maximal horizontal width of graph.
+  int x_count = static_cast<int>(k_line_length * (current_size / max_size)
+                                 + 0.5);
+  int x_remainder = k_line_length - x_count;
+
+  while (0 < x_count--)
+    output->append("-");
+  output->append("O");
+  while (0 < x_remainder--)
+    output->append(" ");
+}
+
+const std::string HistogramBase::GetSimpleAsciiBucketRange(
+    Sample sample) const {
+  std::string result;
+  if (kHexRangePrintingFlag & flags())
+    StringAppendF(&result, "%#x", sample);
+  else
+    StringAppendF(&result, "%d", sample);
+  return result;
+}
+
+void HistogramBase::WriteAsciiBucketValue(Count current,
+                                          double scaled_sum,
+                                          std::string* output) const {
+  StringAppendF(output, " (%d = %3.1f%%)", current, current/scaled_sum);
+}
+
 }  // namespace base

base/metrics/histogram_base.h

@@ -142,6 +142,21 @@ protected:
   // counts to |buckets| and the total sample count to |count|.
   virtual void GetCountAndBucketData(Count* count,
                                      ListValue* buckets) const = 0;
+
+  //// Produce actual graph (set of blank vs non blank char's) for a bucket.
+  void WriteAsciiBucketGraph(double current_size,
+                             double max_size,
+                             std::string* output) const;
+
+  // Return a string description of what goes in a given bucket.
+  const std::string GetSimpleAsciiBucketRange(Sample sample) const;
+
+  // Write textual description of the bucket contents (relative to histogram).
+  // Output is the count in the buckets, as well as the percentage.
+  void WriteAsciiBucketValue(Count current,
+                             double scaled_sum,
+                             std::string* output) const;
+
  private:
   const std::string histogram_name_;
   int32 flags_;

base/metrics/sparse_histogram.cc

@@ -7,6 +7,7 @@
 #include "base/metrics/sample_map.h"
 #include "base/metrics/statistics_recorder.h"
 #include "base/pickle.h"
+#include "base/stringprintf.h"
 #include "base/synchronization/lock.h"
 
 using std::map;
@@ -69,11 +70,13 @@ bool SparseHistogram::AddSamplesFromPickle(PickleIterator* iter) {
 }
 
 void SparseHistogram::WriteHTMLGraph(string* output) const {
-  // TODO(kaiwang): Implement.
+  output->append("<PRE>");
+  WriteAsciiImpl(true, "<br>", output);
+  output->append("</PRE>");
 }
 
 void SparseHistogram::WriteAscii(string* output) const {
-  // TODO(kaiwang): Implement.
+  WriteAsciiImpl(true, "\n", output);
 }
 
 bool SparseHistogram::SerializeInfoImpl(Pickle* pickle) const {
@@ -106,4 +109,69 @@ void SparseHistogram::GetCountAndBucketData(Count* count,
   // TODO(kaiwang): Implement. (See HistogramBase::WriteJSON.)
 }
 
+void SparseHistogram::WriteAsciiImpl(bool graph_it,
+                                     const std::string& newline,
+                                     std::string* output) const {
+  // Get a local copy of the data so we are consistent.
+  scoped_ptr<HistogramSamples> snapshot = SnapshotSamples();
+  Count total_count = snapshot->TotalCount();
+  double scaled_total_count = total_count / 100.0;
+
+  WriteAsciiHeader(total_count, output);
+  output->append(newline);
+
+  // Determine how wide the largest bucket range is (how many digits to print),
+  // so that we'll be able to right-align starts for the graphical bars.
+  // Determine which bucket has the largest sample count so that we can
+  // normalize the graphical bar-width relative to that sample count.
+  Count largest_count = 0;
+  Sample largest_sample = 0;
+  scoped_ptr<SampleCountIterator> it = snapshot->Iterator();
+  while (!it->Done())
+  {
+    Sample min;
+    Sample max;
+    Count count;
+    it->Get(&min, &max, &count);
+    if (min > largest_sample)
+      largest_sample = min;
+    if (count > largest_count)
+      largest_count = count;
+    it->Next();
+  }
+  size_t print_width = GetSimpleAsciiBucketRange(largest_sample).size() + 1;
+
+  // iterate over each item and display them
+  it = snapshot->Iterator();
+  while (!it->Done())
+  {
+    Sample min;
+    Sample max;
+    Count count;
+    it->Get(&min, &max, &count);
+
+    // value is min, so display it
+    string range = GetSimpleAsciiBucketRange(min);
+    output->append(range);
+    for (size_t j = 0; range.size() + j < print_width + 1; ++j)
+      output->push_back(' ');
+
+    if (graph_it)
+      WriteAsciiBucketGraph(count, largest_count, output);
+    WriteAsciiBucketValue(count, scaled_total_count, output);
+    output->append(newline);
+    it->Next();
+  }
+}
+
+void SparseHistogram::WriteAsciiHeader(const Count total_count,
+                                       std::string* output) const {
+  StringAppendF(output,
+                "Histogram: %s recorded %d samples",
+                histogram_name().c_str(),
+                total_count);
+  if (flags() & ~kHexRangePrintingFlag)
+    StringAppendF(output, " (flags = 0x%x)", flags() & ~kHexRangePrintingFlag);
+}
+
 }  // namespace base

base/metrics/sparse_histogram.h

@@ -90,6 +90,15 @@ class BASE_EXPORT_PRIVATE SparseHistogram : public HistogramBase {
   virtual void GetCountAndBucketData(Count* count,
                                      ListValue* buckets) const OVERRIDE;
 
+  // Helpers for emitting Ascii graphic.  Each method appends data to output.
+  void WriteAsciiImpl(bool graph_it,
+                      const std::string& newline,
+                      std::string* output) const;
+
+  // Write a common header message describing this histogram.
+  void WriteAsciiHeader(const Count total_count,
+                        std::string* output) const;
+
   // For constuctor calling.
   friend class SparseHistogramTest;