| // 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/heap_profiler_type_name_deduplicator.h" |
| |
| #include <stddef.h> |
| #include <stdlib.h> |
| #include <string> |
| #include <utility> |
| |
| #include "base/json/string_escape.h" |
| #include "base/strings/stringprintf.h" |
| #include "base/trace_event/trace_event_memory_overhead.h" |
| |
| namespace base { |
| namespace trace_event { |
| |
| namespace { |
| |
| // Extract directory name if |type_name| was file name. Otherwise, return |
| // |type_name|. |
| StringPiece ExtractDirNameFromFileName(const char* type_name) { |
| StringPiece result(type_name); |
| size_t last_seperator = result.find_last_of("\\/"); |
| |
| // If |type_name| was a not a file path, the seperator will not be found, so |
| // the whole type name is returned. |
| if (last_seperator == StringPiece::npos) |
| return result; |
| |
| // Remove the file name from the path. |
| result.remove_suffix(result.length() - last_seperator); |
| |
| // Remove the parent directory references. |
| const char kParentDirectory[] = ".."; |
| const size_t kParentDirectoryLength = 3; // '../' or '..\'. |
| while (result.starts_with(kParentDirectory)) { |
| result.remove_prefix(kParentDirectoryLength); |
| } |
| return result; |
| } |
| |
| } // namespace |
| |
| TypeNameDeduplicator::TypeNameDeduplicator() { |
| // A null pointer has type ID 0 ("unknown type"); |
| type_ids_.insert(std::make_pair(nullptr, 0)); |
| } |
| |
| TypeNameDeduplicator::~TypeNameDeduplicator() {} |
| |
| int TypeNameDeduplicator::Insert(const char* type_name) { |
| auto result = type_ids_.insert(std::make_pair(type_name, 0)); |
| auto& elem = result.first; |
| bool did_not_exist_before = result.second; |
| |
| if (did_not_exist_before) { |
| // The type IDs are assigned sequentially and they are zero-based, so |
| // |size() - 1| is the ID of the new element. |
| elem->second = static_cast<int>(type_ids_.size() - 1); |
| } |
| |
| return elem->second; |
| } |
| |
| void TypeNameDeduplicator::AppendAsTraceFormat(std::string* out) const { |
| out->append("{"); // Begin the type names dictionary. |
| |
| auto it = type_ids_.begin(); |
| std::string buffer; |
| |
| // Write the first entry manually; the null pointer must not be dereferenced. |
| // (The first entry is the null pointer because a |std::map| is ordered.) |
| it++; |
| out->append("\"0\":\"[unknown]\""); |
| |
| for (; it != type_ids_.end(); it++) { |
| // Type IDs in the trace are strings, write them as stringified keys of |
| // a dictionary. |
| SStringPrintf(&buffer, ",\"%d\":", it->second); |
| |
| // TODO(ssid): crbug.com/594803 the type name is misused for file name in |
| // some cases. |
| StringPiece type_info = ExtractDirNameFromFileName(it->first); |
| |
| // |EscapeJSONString| appends, it does not overwrite |buffer|. |
| bool put_in_quotes = true; |
| EscapeJSONString(type_info, put_in_quotes, &buffer); |
| out->append(buffer); |
| } |
| |
| out->append("}"); // End the type names dictionary. |
| } |
| |
| void TypeNameDeduplicator::EstimateTraceMemoryOverhead( |
| TraceEventMemoryOverhead* overhead) { |
| // The size here is only an estimate; it fails to take into account the size |
| // of the tree nodes for the map, but as an estimate this should be fine. |
| size_t map_size = type_ids_.size() * sizeof(std::pair<const char*, int>); |
| |
| overhead->Add("TypeNameDeduplicator", |
| sizeof(TypeNameDeduplicator) + map_size); |
| } |
| |
| } // namespace trace_event |
| } // namespace base |