base/trace_event/memory_allocator_dump.cc

   1 // Copyright 2015 The Chromium Authors. All rights reserved.
   2 // Use of this source code is governed by a BSD-style license that can be
   3 // found in the LICENSE file.
   4
   5 #include "base/trace_event/memory_allocator_dump.h"
   6
   7 #include "base/format_macros.h"
   8 #include "base/strings/stringprintf.h"
   9 #include "base/trace_event/memory_dump_manager.h"
  10 #include "base/trace_event/memory_dump_provider.h"
  11 #include "base/trace_event/process_memory_dump.h"
  12 #include "base/trace_event/trace_event_argument.h"
  13 #include "base/values.h"
  14
  15 namespace base {
  16 namespace trace_event {
  17
  18 namespace {
  19 // Returns the c-string pointer from a dictionary value without performing extra
  20 // std::string copies. The ptr will be valid as long as the value exists.
  21 bool GetDictionaryValueAsCStr(const DictionaryValue* dict_value,
  22                               const std::string& key,
  23                               const char** out_cstr) {
  24   const Value* value = nullptr;
  25   const StringValue* str_value = nullptr;
  26   if (!dict_value->GetWithoutPathExpansion(key, &value))
  27     return false;
  28   if (!value->GetAsString(&str_value))
  29     return false;
  30   *out_cstr = str_value->GetString().c_str();
  31   return true;
  32 }
  33 }  // namespace
  34
  35 const char MemoryAllocatorDump::kNameOuterSize[] = "outer_size";
  36 const char MemoryAllocatorDump::kNameInnerSize[] = "inner_size";
  37 const char MemoryAllocatorDump::kNameObjectsCount[] = "objects_count";
  38 const char MemoryAllocatorDump::kTypeScalar[] = "scalar";
  39 const char MemoryAllocatorDump::kTypeString[] = "string";
  40 const char MemoryAllocatorDump::kUnitsBytes[] = "bytes";
  41 const char MemoryAllocatorDump::kUnitsObjects[] = "objects";
  42
  43 MemoryAllocatorDump::MemoryAllocatorDump(const std::string& absolute_name,
  44                                          ProcessMemoryDump* process_memory_dump)
  45     : absolute_name_(absolute_name), process_memory_dump_(process_memory_dump) {
  46   // The |absolute_name| cannot be empty.
  47   DCHECK(!absolute_name.empty());
  48
  49   // The |absolute_name| can contain slash separator, but not leading or
  50   // trailing ones.
  51   DCHECK(absolute_name[0] != '/' && *absolute_name.rbegin() != '/');
  52
  53   // Dots are not allowed anywhere as the underlying base::DictionaryValue
  54   // would treat them magically and split in sub-nodes, which is not intended.
  55   DCHECK_EQ(std::string::npos, absolute_name.find_first_of('.'));
  56 }
  57
  58 MemoryAllocatorDump::~MemoryAllocatorDump() {
  59 }
  60
  61 void MemoryAllocatorDump::Add(const std::string& name,
  62                               const char* type,
  63                               const char* units,
  64                               scoped_ptr<Value> value) {
  65   scoped_ptr<DictionaryValue> attribute(new DictionaryValue());
  66   DCHECK(!attributes_.HasKey(name));
  67   attribute->SetStringWithoutPathExpansion("type", type);
  68   attribute->SetStringWithoutPathExpansion("units", units);
  69   attribute->SetWithoutPathExpansion("value", value.Pass());
  70   attributes_.SetWithoutPathExpansion(name, attribute.Pass());
  71 }
  72
  73 bool MemoryAllocatorDump::Get(const std::string& name,
  74                               const char** out_type,
  75                               const char** out_units,
  76                               const Value** out_value) const {
  77   const DictionaryValue* attribute = nullptr;
  78   if (!attributes_.GetDictionaryWithoutPathExpansion(name, &attribute))
  79     return false;
  80
  81   if (!GetDictionaryValueAsCStr(attribute, "type", out_type))
  82     return false;
  83
  84   if (!GetDictionaryValueAsCStr(attribute, "units", out_units))
  85     return false;
  86
  87   if (!attribute->GetWithoutPathExpansion("value", out_value))
  88     return false;
  89
  90   return true;
  91 }
  92
  93 void MemoryAllocatorDump::AddScalar(const std::string& name,
  94                                     const char* units,
  95                                     uint64 value) {
  96   scoped_ptr<Value> hex_value(new StringValue(StringPrintf("%" PRIx64, value)));
  97   Add(name, kTypeScalar, units, hex_value.Pass());
  98 }
  99
 100 void MemoryAllocatorDump::AddString(const std::string& name,
 101                                     const char* units,
 102                                     const std::string& value) {
 103   scoped_ptr<Value> str_value(new StringValue(value));
 104   Add(name, kTypeString, units, str_value.Pass());
 105 }
 106
 107 void MemoryAllocatorDump::AsValueInto(TracedValue* value) const {
 108   value->BeginDictionary(absolute_name_.c_str());
 109   value->BeginDictionary("attrs");
 110
 111   for (DictionaryValue::Iterator it(attributes_); !it.IsAtEnd(); it.Advance())
 112     value->SetValue(it.key().c_str(), it.value().DeepCopy());
 113
 114   value->EndDictionary();  // "attrs": { ... }
 115   value->EndDictionary();  // "allocator_name/heap_subheap": { ... }
 116 }
 117
 118 }  // namespace trace_event
 119 }  // namespace base