Extend CPU profiler with mapping ticks to source lines

include/v8-profiler.h

Index: include/v8-profiler.h
diff --git a/include/v8-profiler.h b/include/v8-profiler.h
index 7fc193db58e9ded01a0b857c33134d0aed6b31d1..37392a1cd3f5e31ca5094327d3d3180ca02846d2 100644
--- a/include/v8-profiler.h
+++ b/include/v8-profiler.h
@@ -17,6 +17,14 @@ 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.
  */
@@ -43,6 +51,17 @@ class V8_EXPORT CpuProfileNode {
    */
   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.
     */