Add searching features to new TraceEventVector class for tests.

base/test/trace_event_analyzer.h

Index: base/test/trace_event_analyzer.h
diff --git a/base/test/trace_event_analyzer.h b/base/test/trace_event_analyzer.h
index 5e40a062727e9b74755b299d9f4f591973c5e281..cd9a8b3645f22ecfe0c4c702687d38c7388666bc 100644
--- a/base/test/trace_event_analyzer.h
+++ b/base/test/trace_event_analyzer.h
@@ -415,18 +415,55 @@ class QueryNode : public base::RefCounted<QueryNode> {
   Query query_;
 };
 
-// TraceAnalyzer helps tests search for trace events.
-class TraceAnalyzer {
+class TraceEventVector : public std::vector<const TraceEvent*> {

[Paweł Hajdan Jr., 2011/12/12 17:21:51]

Inheritance from std::vector? I'm suspicious. Could you explain more why you're
doing that?

[jbates, 2011/12/12 22:00:32]

Done.

  public:
-  typedef std::vector<const TraceEvent*> TraceEventVector;
-
-  struct Stats {
+  struct RateStats {
     double min_us;
     double max_us;
     double mean_us;
     double standard_deviation_us;
   };
 
+  // Calculate min/max/mean and standard deviation from the times between
+  // adjacent events.
+  bool GetRateStats(RateStats* stats);
+
+  // Starting from |position|, find the first event that matches |query|.
+  // Returns true if found, false otherwise.
+  bool FindFirstOf(Query query,
+                   size_t position,
+                   size_t* return_index) const;
+
+  // Starting from |position|, find the last event that matches |query|.
+  // Returns true if found, false otherwise.
+  bool FindLastOf(Query query,
+                  size_t position,
+                  size_t* return_index) const;
+
+  // Find the closest events to |position| in time that match |query|.
+  // return_second_closest may be NULL. Closeness is determined by comparing
+  // with the event timestamp.
+  // Returns true if found, false otherwise. If both return parameters are
+  // requested, both must be found for a successful result.
+  bool FindClosest(Query query,
+                   size_t position,
+                   size_t* return_closest,
+                   size_t* return_second_closest) const;

[Paweł Hajdan Jr., 2011/12/12 17:21:51]

nit: If second_closest is there, why not third_closest and so on? Would it help
to have a method like that to only return the first value, and then another one
to return a sorted vector?

[jbates, 2011/12/12 22:00:32]

Returning a sorted vector did occur to me, but one or two satisfies all the use
cases I can think of. Basically, the second one is just to find out if the event
was very close to the closest, or if it was closer to the mid-point between two
events. Going from 2 to n adds some complexity, so I didn't think it was worth
it without some use cases.

+
+  // Count matches, inclusive of |begin_position|, exclusive of |end_position|.
+  int CountMatches(Query query,

[Paweł Hajdan Jr., 2011/12/12 17:21:51]

nit: If size_t is generally used, why this and method below return int?

[jbates, 2011/12/12 22:00:32]

Done.

+                   size_t begin_position,
+                   size_t end_position) const;
+
+  // Count all matches.
+  int CountMatches(Query query) const {
+    return CountMatches(query, 0, size());
+  }
+};
+
+// TraceAnalyzer helps tests search for trace events.
+class TraceAnalyzer {
+ public:
   ~TraceAnalyzer();
 
   // Use trace events from JSON string generated by tracing API.
@@ -474,6 +511,10 @@ class TraceAnalyzer {
                        const Query& second,
                        const Query& match);
 
+  // For each event, copy its arguments to the other_event argument map. If
+  // argument name already exists, it will not be overwritten.
+  void MergeAssociatedEventArgs();
+
   // Find all events that match query and replace output vector.
   size_t FindEvents(const Query& query, TraceEventVector* output);
 
@@ -482,10 +523,6 @@ class TraceAnalyzer {
 
   const std::string& GetThreadName(const TraceEvent::ProcessThreadID& thread);
 
-  // Calculate min/max/mean and standard deviation from the times between
-  // adjacent events.
-  static bool GetRateStats(const TraceEventVector& events, Stats* stats);
-
  private:
   TraceAnalyzer();