Refactor the functions related to collecting code statistics to a new class.

src/heap/code-stats.cc

Index: src/heap/code-stats.cc
diff --git a/src/heap/code-stats.cc b/src/heap/code-stats.cc
new file mode 100644
index 0000000000000000000000000000000000000000..d4ff5fbba75c4ba010350de0bdea694d9250b329
--- /dev/null
+++ b/src/heap/code-stats.cc
@@ -0,0 +1,220 @@
+// Copyright 2016 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.
+
+#include "src/heap/code-stats.h"
+#include "src/objects-inl.h"
+
+namespace v8 {
+namespace internal {
+
+// Record code statisitcs.
+void CodeStatistics::RecordCodeAndMetadataStatistics(HeapObject* object,
+                                                     Isolate* isolate) {
+  if (!object->IsAbstractCode()) {
+    return;
+  }
+
+  // Record code+metadata statisitcs.
+  AbstractCode* abstract_code = AbstractCode::cast(object);
+  int size = abstract_code->SizeIncludingMetadata();
+  if (abstract_code->IsCode()) {
+    size += isolate->code_and_metadata_size();
+    isolate->set_code_and_metadata_size(size);
+  } else {
+    size += isolate->bytecode_and_metadata_size();
+    isolate->set_bytecode_and_metadata_size(size);
+  }
+
+#ifdef DEBUG
+  // Record code kind and code comment statistics.
+  isolate->code_kind_statistics()[abstract_code->kind()] +=
+      abstract_code->Size();
+  CodeStatistics::CollectCodeCommentStatistics(object, isolate);
+#endif
+}
+
+void CodeStatistics::ResetCodeAndMetadataStatistics(Isolate* isolate) {
+  isolate->set_code_and_metadata_size(0);
+  isolate->set_bytecode_and_metadata_size(0);
+#ifdef DEBUG
+  ResetCodeStatistics(isolate);
+#endif
+}
+
+// Collects code size statistics:
+// - code and metadata size
+// - by code kind (only in debug mode)
+// - by code comment (only in debug mode)
+void CodeStatistics::CollectCodeStatistics(PagedSpace* space,
+                                           Isolate* isolate) {
+  HeapObjectIterator obj_it(space);
+  for (HeapObject* obj = obj_it.Next(); obj != NULL; obj = obj_it.Next()) {
+    RecordCodeAndMetadataStatistics(obj, isolate);
+  }
+}
+
+// Collects code size statistics in LargeObjectSpace:
+// - code and metadata size
+// - by code kind (only in debug mode)
+// - by code comment (only in debug mode)
+void CodeStatistics::CollectCodeStatistics(LargeObjectSpace* space,
+                                           Isolate* isolate) {
+  LargeObjectIterator obj_it(space);
+  for (HeapObject* obj = obj_it.Next(); obj != NULL; obj = obj_it.Next()) {
+    RecordCodeAndMetadataStatistics(obj, isolate);
+  }
+}
+
+#ifdef DEBUG
+void CodeStatistics::ReportCodeStatistics(Isolate* isolate) {
+  // Report code kind statistics
+  int* code_kind_statistics = isolate->code_kind_statistics();
+  PrintF("\n   Code kind histograms: \n");
+  for (int i = 0; i < AbstractCode::NUMBER_OF_KINDS; i++) {
+    if (code_kind_statistics[i] > 0) {
+      PrintF("     %-20s: %10d bytes\n",
+             AbstractCode::Kind2String(static_cast<AbstractCode::Kind>(i)),
+             code_kind_statistics[i]);
+    }
+  }
+  PrintF("\n");
+
+  // Report code and metadata statisitcs
+  if (isolate->code_and_metadata_size() > 0) {
+    PrintF("Code size including metadata    : %10d bytes\n",
+           isolate->code_and_metadata_size());
+  }
+  if (isolate->bytecode_and_metadata_size() > 0) {
+    PrintF("Bytecode size including metadata: %10d bytes\n",
+           isolate->bytecode_and_metadata_size());
+  }
+
+  // Report code comment statistics
+  CommentStatistic* comments_statistics =
+      isolate->paged_space_comments_statistics();
+  PrintF(
+      "Code comment statistics (\"   [ comment-txt   :    size/   "
+      "count  (average)\"):\n");
+  for (int i = 0; i <= CommentStatistic::kMaxComments; i++) {
+    const CommentStatistic& cs = comments_statistics[i];
+    if (cs.size > 0) {
+      PrintF("   %-30s: %10d/%6d     (%d)\n", cs.comment, cs.size, cs.count,
+             cs.size / cs.count);
+    }
+  }
+  PrintF("\n");
+}
+
+void CodeStatistics::ResetCodeStatistics(Isolate* isolate) {
+  // Clear code kind statistics
+  int* code_kind_statistics = isolate->code_kind_statistics();
+  for (int i = 0; i < AbstractCode::NUMBER_OF_KINDS; i++) {
+    code_kind_statistics[i] = 0;
+  }
+
+  // Clear code comment statistics
+  CommentStatistic* comments_statistics =
+      isolate->paged_space_comments_statistics();
+  for (int i = 0; i < CommentStatistic::kMaxComments; i++) {
+    comments_statistics[i].Clear();
+  }
+  comments_statistics[CommentStatistic::kMaxComments].comment = "Unknown";
+  comments_statistics[CommentStatistic::kMaxComments].size = 0;
+  comments_statistics[CommentStatistic::kMaxComments].count = 0;
+}
+
+// Adds comment to 'comment_statistics' table. Performance OK as long as
+// 'kMaxComments' is small
+void CodeStatistics::EnterComment(Isolate* isolate, const char* comment,
+                                  int delta) {
+  CommentStatistic* comments_statistics =
+      isolate->paged_space_comments_statistics();
+  // Do not count empty comments
+  if (delta <= 0) return;
+  CommentStatistic* cs = &comments_statistics[CommentStatistic::kMaxComments];
+  // Search for a free or matching entry in 'comments_statistics': 'cs'
+  // points to result.
+  for (int i = 0; i < CommentStatistic::kMaxComments; i++) {
+    if (comments_statistics[i].comment == NULL) {
+      cs = &comments_statistics[i];
+      cs->comment = comment;
+      break;
+    } else if (strcmp(comments_statistics[i].comment, comment) == 0) {
+      cs = &comments_statistics[i];
+      break;
+    }
+  }
+  // Update entry for 'comment'
+  cs->size += delta;
+  cs->count += 1;
+}
+
+// Call for each nested comment start (start marked with '[ xxx', end marked
+// with ']'.  RelocIterator 'it' must point to a comment reloc info.
+void CodeStatistics::CollectCommentStatistics(Isolate* isolate,
+                                              RelocIterator* it) {
+  DCHECK(!it->done());
+  DCHECK(it->rinfo()->rmode() == RelocInfo::COMMENT);
+  const char* tmp = reinterpret_cast<const char*>(it->rinfo()->data());
+  if (tmp[0] != '[') {
+    // Not a nested comment; skip
+    return;
+  }
+
+  // Search for end of nested comment or a new nested comment
+  const char* const comment_txt =
+      reinterpret_cast<const char*>(it->rinfo()->data());
+  const byte* prev_pc = it->rinfo()->pc();
+  int flat_delta = 0;
+  it->next();
+  while (true) {
+    // All nested comments must be terminated properly, and therefore exit
+    // from loop.
+    DCHECK(!it->done());
+    if (it->rinfo()->rmode() == RelocInfo::COMMENT) {
+      const char* const txt =
+          reinterpret_cast<const char*>(it->rinfo()->data());
+      flat_delta += static_cast<int>(it->rinfo()->pc() - prev_pc);
+      if (txt[0] == ']') break;  // End of nested  comment
+      // A new comment
+      CollectCommentStatistics(isolate, it);
+      // Skip code that was covered with previous comment
+      prev_pc = it->rinfo()->pc();
+    }
+    it->next();
+  }
+  EnterComment(isolate, comment_txt, flat_delta);
+}
+
+// Collects code comment statistics
+void CodeStatistics::CollectCodeCommentStatistics(HeapObject* obj,
+                                                  Isolate* isolate) {
+  // Bytecode objects do not contain RelocInfo. Only process code objects
+  // for code comment statistics.
+  if (!obj->IsCode()) {
+    return;
+  }
+
+  Code* code = Code::cast(obj);
+  RelocIterator it(code);
+  int delta = 0;
+  const byte* prev_pc = code->instruction_start();
+  while (!it.done()) {
+    if (it.rinfo()->rmode() == RelocInfo::COMMENT) {
+      delta += static_cast<int>(it.rinfo()->pc() - prev_pc);
+      CollectCommentStatistics(isolate, &it);
+      prev_pc = it.rinfo()->pc();
+    }
+    it.next();
+  }
+
+  DCHECK(code->instruction_start() <= prev_pc &&
+         prev_pc <= code->instruction_end());
+  delta += static_cast<int>(code->instruction_end() - prev_pc);
+  EnterComment(isolate, "NoComment", delta);
+}
+#endif
+
+}  // namespace internal
+}  // namespace v8