[Tracing] Introduce HeapDumpWriter helper class

base/trace_event/process_memory_dump.cc

 // Copyright 2015 The Chromium 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 "base/trace_event/process_memory_dump.h"
 
 #include <vector>
 
 #include "base/process/process_metrics.h"
 #include "base/stl_util.h"
@@ skipping 127 matching lines @@
   return allocator_dump ? allocator_dump
                         : CreateAllocatorDump(
                               GetSharedGlobalAllocatorDumpName(guid), guid);
 }
 
 MemoryAllocatorDump* ProcessMemoryDump::GetSharedGlobalAllocatorDump(
     const MemoryAllocatorDumpGuid& guid) const {
   return GetAllocatorDump(GetSharedGlobalAllocatorDumpName(guid));
 }
 
+void ProcessMemoryDump::AddHeapDump(const std::string& absolute_name,
+                                    scoped_refptr<TracedValue> heap_dump) {
+  DCHECK_EQ(0ul, heap_dumps_.count(absolute_name));
+  heap_dumps_[absolute_name] = heap_dump;
+}
+
 void ProcessMemoryDump::Clear() {
   if (has_process_totals_) {
     process_totals_.Clear();
     has_process_totals_ = false;
   }
 
   if (has_process_mmaps_) {
     process_mmaps_.Clear();
     has_process_mmaps_ = false;
   }
 
   allocator_dumps_storage_.clear();
   allocator_dumps_.clear();
   allocator_dumps_edges_.clear();
+  heap_dumps_.clear();
 }
 
 void ProcessMemoryDump::TakeAllDumpsFrom(ProcessMemoryDump* other) {
   DCHECK(!other->has_process_totals() && !other->has_process_mmaps());
 
   // Moves the ownership of all MemoryAllocatorDump(s) contained in |other|
   // into this ProcessMemoryDump.
   for (MemoryAllocatorDump* mad : other->allocator_dumps_storage_) {
     // Check that we don't merge duplicates.
     DCHECK_EQ(0ul, allocator_dumps_.count(mad->absolute_name()));
     allocator_dumps_storage_.push_back(mad);
     allocator_dumps_[mad->absolute_name()] = mad;
   }
   other->allocator_dumps_storage_.weak_clear();
   other->allocator_dumps_.clear();
 
   // Move all the edges.
   allocator_dumps_edges_.insert(allocator_dumps_edges_.end(),
                                 other->allocator_dumps_edges_.begin(),
                                 other->allocator_dumps_edges_.end());
   other->allocator_dumps_edges_.clear();
+
+  heap_dumps_.insert(other->heap_dumps_.begin(), other->heap_dumps_.end());
+  other->heap_dumps_.clear();
 }
 
 void ProcessMemoryDump::AsValueInto(TracedValue* value) const {
   if (has_process_totals_) {
     value->BeginDictionary("process_totals");
     process_totals_.AsValueInto(value);
     value->EndDictionary();
   }
 
   if (has_process_mmaps_) {
     value->BeginDictionary("process_mmaps");
     process_mmaps_.AsValueInto(value);
     value->EndDictionary();
   }
 
   if (allocator_dumps_storage_.size() > 0) {
     value->BeginDictionary("allocators");
     for (const MemoryAllocatorDump* allocator_dump : allocator_dumps_storage_)
       allocator_dump->AsValueInto(value);
     value->EndDictionary();
   }
 
+  if (heap_dumps_.size() > 0) {
+    value->BeginDictionary("heaps");
+    for (const auto& name_and_dump : heap_dumps_)
+      value->SetValueWithCopiedName(name_and_dump.first, *name_and_dump.second);
+    value->EndDictionary();  // "heaps"
+  }
+
   value->BeginArray("allocators_graph");
   for (const MemoryAllocatorDumpEdge& edge : allocator_dumps_edges_) {
     value->BeginDictionary();
     value->SetString("source", edge.source.ToString());
     value->SetString("target", edge.target.ToString());
     value->SetInteger("importance", edge.importance);
     value->SetString("type", edge.type);
     value->EndDictionary();
   }
   value->EndArray();
@@ skipping 14 matching lines @@
 
 void ProcessMemoryDump::AddSuballocation(const MemoryAllocatorDumpGuid& source,
                                          const std::string& target_node_name) {
   std::string child_mad_name = target_node_name + "/__" + source.ToString();
   MemoryAllocatorDump* target_child_mad = CreateAllocatorDump(child_mad_name);
   AddOwnershipEdge(source, target_child_mad->guid());
 }
 
 }  // namespace trace_event
 }  // namespace base