Coverage API revamp

runtime/vm/coverage.h

Index: runtime/vm/coverage.h
diff --git a/runtime/vm/coverage.h b/runtime/vm/coverage.h
index 72c639ae01844c7b531516fc877034e66619e72c..12c4023fa882ec2e55d0bcc48cdef1c5c49ea0a6 100644
--- a/runtime/vm/coverage.h
+++ b/runtime/vm/coverage.h
@@ -23,20 +23,27 @@ class Library;
 class Script;
 class String;
 
+class CoverageFilter : public ValueObject {
+ public:
+  virtual bool GetCoverage(const Library& lib,

[Michael Lippautz (Google), 2014/06/27 00:16:48]

Performance of using only one filter function (and therefore iterate over all
libraries, classes, and functions) is 3x slower than with fine-grained (separate
methods) filtering. 

Still in domain of milliseconds (~30ms).

[Cutch, 2014/06/27 15:07:19]

Maybe rename to "ShouldOutputCoverageFor"

Also, mark it as const.

[Michael Lippautz (Google), 2014/06/27 17:12:24]

Done.

+                           const Script& script,
+                           const Class& cls,
+                           const Function& func) = 0;
+  virtual ~CoverageFilter() {}
+};
+
 class CodeCoverage : public AllStatic {
  public:
   static void Write(Isolate* isolate);
-  static void PrintJSON(Isolate* isolate, JSONStream* stream);
-
-  static void PrintJSONForScript(const Script& script, JSONStream* stream);
-  static void PrintJSONForLibrary(
-      const Library& lib, const Script& script_filter, JSONStream* stream);
-  static void PrintJSONForClass(const Class& lib, JSONStream* stream);
+  static void PrintJSON(Isolate* isolate,
+                        JSONStream* stream,
+                        CoverageFilter* filter);
 
  private:
-  static void PrintClass(const Class& cls,
+  static void PrintClass(const Library& lib,
+                         const Class& cls,
                          const JSONArray& arr,
-                         const Script& script_filter);
+                         CoverageFilter* filter);
   static void CompileAndAdd(const Function& function,
                             const JSONArray& hits_arr,
                             const GrowableArray<intptr_t>& pos_to_line);