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..dbb6d3ba9370a1ba663542f37ce287d5638d6bae 100644
--- a/include/v8-profiler.h
+++ b/include/v8-profiler.h
@@ -22,6 +22,14 @@ typedef uint32_t SnapshotObjectId;
  */
 class V8_EXPORT CpuProfileNode {
  public:
+  typedef struct {

[yurys, 2014/08/08 08:13:23]

style: we use C++ style for struct declaration.

struct LineTick {
...
}

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

[yurys, 2014/08/08 08:13:23]

How about providing column as well which I already suggested before? On minified
sources line number doesn't give enough information as the whole script may be
formatted as one line.

[Denis Pravdin, 2014/08/11 05:35:31]

The minified sources is useful to reduce the amount data that needs to be
transferred. It's difficult and inconvenient to use them for profiling purpose.
When developer identifies a position (column in alone line representing his
script) that impacts performance that next step is modification of source code.
I'm not sure that the minified sources give a convenient way to understand a
logic of the algorithm implemented in a function, it's better to use original
version of source file. That's why I would suggest not to provide column in this
patch. We always can do that if the customers find it useful for profiling. What
do you think?

+
+    /** The count of samples associated with the source line. */
+    unsigned int hit_count;
+  } LineTick;
+
   /** Returns function name (empty string for anonymous functions.) */
   Handle<String> GetFunctionName() const;
 
@@ -43,6 +51,18 @@ 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.
+   *  The function copies nothing if buffer is not large enough.
+   */
+  bool GetLineTicks(LineTick* entries, unsigned int number) const;
+
   /** Returns bailout reason for the function
     * if the optimization was disabled for it.
     */