Implement tick events compression in a log file.

src/log.h

 // Copyright 2006-2008 the V8 project authors. All rights reserved.
 // Redistribution and use in source and binary forms, with or without
 // modification, are permitted provided that the following conditions are
 // met:
 //
 //     * Redistributions of source code must retain the above copyright
 //       notice, this list of conditions and the following disclaimer.
 //     * Redistributions in binary form must reproduce the above
 //       copyright notice, this list of conditions and the following
 //       disclaimer in the documentation and/or other materials provided
@@ skipping 89 matching lines @@
   explicit VMState(StateTag state) {}
 #endif
 };
 
 
 #define LOG_EVENTS_AND_TAGS_LIST(V) \
   V(CODE_CREATION_EVENT,            "code-creation",          "cc")       \
   V(CODE_MOVE_EVENT,                "code-move",              "cm")       \
   V(CODE_DELETE_EVENT,              "code-delete",            "cd")       \
   V(TICK_EVENT,                     "tick",                   "t")        \
+  V(REPEAT_META_EVENT,              "repeat",                 "r")        \
   V(BUILTIN_TAG,                    "Builtin",                "bi")       \
   V(CALL_DEBUG_BREAK_TAG,           "CallDebugBreak",         "cdb")      \
   V(CALL_DEBUG_PREPARE_STEP_IN_TAG, "CallDebugPrepareStepIn", "cdbsi")    \
   V(CALL_IC_TAG,                    "CallIC",                 "cic")      \
   V(CALL_INITIALIZE_TAG,            "CallInitialize",         "ci")       \
   V(CALL_MEGAMORPHIC_TAG,           "CallMegamorphic",        "cmm")      \
   V(CALL_MISS_TAG,                  "CallMiss",               "cm")       \
   V(CALL_NORMAL_TAG,                "CallNormal",             "cn")       \
   V(CALL_PRE_MONOMORPHIC_TAG,       "CallPreMonomorphic",     "cpm")      \
   V(EVAL_TAG,                       "Eval",                   "e")        \
@@ skipping 172 matching lines @@
   // Singleton bottom or default vm state.
   static VMState bottom_state_;
 
   // SlidingStateWindow instance keeping a sliding window of the most
   // recent VM states.
   static SlidingStateWindow* sliding_state_window_;
 
   // An array of log events names.
   static const char** log_events_;
 
+  // Counter for repeated tick events.
+  static int tick_repeat_count_;
+
   // Internal implementation classes with access to
   // private members.
   friend class EventLog;
   friend class TimeLog;
   friend class Profiler;
   friend class SlidingStateWindow;
   friend class VMState;
 
   friend class LoggerTestHelper;
 #else
   static bool is_enabled() { return false; }
 #endif
 };
 
 
 // Class that extracts stack trace, used for profiling.
 class StackTracer : public AllStatic {
  public:
   static void Trace(TickSample* sample);
 };
 
 
 } }  // namespace v8::internal
 
 #endif  // V8_LOG_H_