[profiler] Implement POC Sampling Heap Profiler

src/profiler/heap-snapshot-generator.cc

 // Copyright 2013 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/profiler/heap-snapshot-generator.h"
 
 #include "src/code-stubs.h"
 #include "src/conversions.h"
 #include "src/debug/debug.h"
 #include "src/objects-body-descriptors.h"
@@ skipping 2594 matching lines @@
 }
 
 
 bool HeapSnapshotGenerator::FillReferences() {
   SnapshotFiller filler(snapshot_, &entries_);
   return v8_heap_explorer_.IterateAndExtractReferences(&filler)
       && dom_explorer_.IterateAndExtractReferences(&filler);
 }
 
 
-template<int bytes> struct MaxDecimalDigitsIn;
-template<> struct MaxDecimalDigitsIn<4> {
-  static const int kSigned = 11;
-  static const int kUnsigned = 10;
-};
-template<> struct MaxDecimalDigitsIn<8> {
-  static const int kSigned = 20;
-  static const int kUnsigned = 20;
-};
-
-
-class OutputStreamWriter {
- public:
-  explicit OutputStreamWriter(v8::OutputStream* stream)
-      : stream_(stream),
-        chunk_size_(stream->GetChunkSize()),
-        chunk_(chunk_size_),
-        chunk_pos_(0),
-        aborted_(false) {
-    DCHECK(chunk_size_ > 0);
-  }
-  bool aborted() { return aborted_; }
-  void AddCharacter(char c) {
-    DCHECK(c != '\0');
-    DCHECK(chunk_pos_ < chunk_size_);
-    chunk_[chunk_pos_++] = c;
-    MaybeWriteChunk();
-  }
-  void AddString(const char* s) {
-    AddSubstring(s, StrLength(s));
-  }
-  void AddSubstring(const char* s, int n) {
-    if (n <= 0) return;
-    DCHECK(static_cast<size_t>(n) <= strlen(s));
-    const char* s_end = s + n;
-    while (s < s_end) {
-      int s_chunk_size =
-          Min(chunk_size_ - chunk_pos_, static_cast<int>(s_end - s));
-      DCHECK(s_chunk_size > 0);
-      MemCopy(chunk_.start() + chunk_pos_, s, s_chunk_size);
-      s += s_chunk_size;
-      chunk_pos_ += s_chunk_size;
-      MaybeWriteChunk();
-    }
-  }
-  void AddNumber(unsigned n) { AddNumberImpl<unsigned>(n, "%u"); }
-  void Finalize() {
-    if (aborted_) return;
-    DCHECK(chunk_pos_ < chunk_size_);
-    if (chunk_pos_ != 0) {
-      WriteChunk();
-    }
-    stream_->EndOfStream();
-  }
-
- private:
-  template<typename T>
-  void AddNumberImpl(T n, const char* format) {
-    // Buffer for the longest value plus trailing \0
-    static const int kMaxNumberSize =
-        MaxDecimalDigitsIn<sizeof(T)>::kUnsigned + 1;
-    if (chunk_size_ - chunk_pos_ >= kMaxNumberSize) {
-      int result = SNPrintF(
-          chunk_.SubVector(chunk_pos_, chunk_size_), format, n);
-      DCHECK(result != -1);
-      chunk_pos_ += result;
-      MaybeWriteChunk();
-    } else {
-      EmbeddedVector<char, kMaxNumberSize> buffer;
-      int result = SNPrintF(buffer, format, n);
-      USE(result);
-      DCHECK(result != -1);
-      AddString(buffer.start());
-    }
-  }
-  void MaybeWriteChunk() {
-    DCHECK(chunk_pos_ <= chunk_size_);
-    if (chunk_pos_ == chunk_size_) {
-      WriteChunk();
-    }
-  }
-  void WriteChunk() {
-    if (aborted_) return;
-    if (stream_->WriteAsciiChunk(chunk_.start(), chunk_pos_) ==
-        v8::OutputStream::kAbort) aborted_ = true;
-    chunk_pos_ = 0;
-  }
-
-  v8::OutputStream* stream_;
-  int chunk_size_;
-  ScopedVector<char> chunk_;
-  int chunk_pos_;
-  bool aborted_;
-};
-
-
 // type, name|index, to_node.
 const int HeapSnapshotJSONSerializer::kEdgeFieldsCount = 3;
 // type, name, id, self_size, edge_count, trace_node_id.
 const int HeapSnapshotJSONSerializer::kNodeFieldsCount = 6;
 
 void HeapSnapshotJSONSerializer::Serialize(v8::OutputStream* stream) {
   if (AllocationTracker* allocation_tracker =
       snapshot_->profiler()->allocation_tracker()) {
     allocation_tracker->PrepareForSerialization();
   }
@@ skipping 440 matching lines @@
   for (int i = 1; i < sorted_strings.length(); ++i) {
     writer_->AddCharacter(',');
     SerializeString(sorted_strings[i]);
     if (writer_->aborted()) return;
   }
 }
 
 
 }  // namespace internal
 }  // namespace v8