Extend CPU profiler with mapping ticks to source lines

include/v8-profiler.h

 // Copyright 2010 the V8 project authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #ifndef V8_V8_PROFILER_H_
 #define V8_V8_PROFILER_H_
 
 #include "v8.h"
 
 /**
  * Profiler support for the V8 JavaScript engine.
  */
 namespace v8 {
 
 class HeapGraphNode;
 struct HeapStatsUpdate;
 
 typedef uint32_t SnapshotObjectId;
 
+typedef struct {

[yurys, 2014/07/29 13:15:10]

struct LineTick, also it can be nested in CpuProfileNode

+  /** The 1-based number of the source line where the function originates. */
+  unsigned int line;

[yurys, 2014/07/29 13:15:10]

Why only line number, column would also be interesting for minfied sources?
Internally you could store map: position -> tick count and convert positions to
(line, column) pairs when returning results.

+
+  /** The count of samples associated with the source line. */
+  unsigned int ticks;

[alph, 2014/07/29 12:55:55]

hitCount?

+} LineTick;
+
 /**
  * CpuProfileNode represents a node in a call graph.
  */
 class V8_EXPORT CpuProfileNode {
  public:
   /** Returns function name (empty string for anonymous functions.) */
   Handle<String> GetFunctionName() const;
 
   /** Returns id of the script where function is located. */
   int GetScriptId() const;
 
   /** Returns resource name for script from where the function originates. */
   Handle<String> GetScriptResourceName() const;
 
   /**
    * Returns the number, 1-based, of the line where the function originates.
    * kNoLineNumberInfo if no line number information is available.
    */
   int GetLineNumber() const;
 
   /**
    * Returns 1-based number of the column where the function originates.
    * kNoColumnNumberInfo if no column number information is available.
    */
   int GetColumnNumber() const;
 
+  /**
+   * Returns the number of the function's source lines that collect the samples.
+   */
+  unsigned int GetHitLineCount() const;
+
+  /** Returns the set of source lines that collect the samples.
+   *  The caller allocates buffer and responsible for releasing it.
+   *  True if all available entries are copied, otherwise false.

[alph, 2014/07/29 12:55:55]

According to the implementation it copies nothing if buffer is not large enough.
I think it should be stated more clearly here.

+   */
+  bool GetLineTicks(LineTick* entries, unsigned int number) const;
+
   /** Returns bailout reason for the function
     * if the optimization was disabled for it.
     */
   const char* GetBailoutReason() const;
 
   /**
     * Returns the count of samples where the function was currently executing.
     */
   unsigned GetHitCount() const;
 
@@ skipping 546 matching lines @@
   uint32_t index;  // Index of the time interval that was changed.
   uint32_t count;  // New value of count field for the interval with this index.
   uint32_t size;  // New value of size field for the interval with this index.
 };
 
 
 }  // namespace v8
 
 
 #endif  // V8_V8_PROFILER_H_