Nagram/TMessagesProj/jni/webrtc/base/metrics/persistent_histogram_storage.cc
2020-08-14 19:58:22 +03:00

152 lines
5.1 KiB
C++

// Copyright 2018 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/metrics/persistent_histogram_storage.h"
#include "base/files/file_util.h"
#include "base/files/important_file_writer.h"
#include "base/logging.h"
#include "base/metrics/persistent_histogram_allocator.h"
#include "base/metrics/persistent_memory_allocator.h"
#include "base/process/memory.h"
#include "base/strings/string_util.h"
#include "base/strings/stringprintf.h"
#include "base/time/time.h"
#include "build/build_config.h"
#if defined(OS_WIN)
#include <windows.h>
// Dummy line to stop `git cl format` from reordering these includes.
#include <memoryapi.h>
#elif defined(OS_POSIX) || defined(OS_FUCHSIA)
#include <sys/mman.h>
#endif
namespace {
constexpr size_t kAllocSize = 1 << 20; // 1 MiB
void* AllocateLocalMemory(size_t size) {
void* address;
#if defined(OS_WIN)
address =
::VirtualAlloc(nullptr, size, MEM_RESERVE | MEM_COMMIT, PAGE_READWRITE);
if (address)
return address;
#elif defined(OS_POSIX) || defined(OS_FUCHSIA)
// MAP_ANON is deprecated on Linux but MAP_ANONYMOUS is not universal on Mac.
// MAP_SHARED is not available on Linux <2.4 but required on Mac.
address = ::mmap(nullptr, size, PROT_READ | PROT_WRITE, MAP_ANON | MAP_SHARED,
-1, 0);
if (address != MAP_FAILED)
return address;
#else
#error This architecture is not (yet) supported.
#endif
// As a last resort, just allocate the memory from the heap. This will
// achieve the same basic result but the acquired memory has to be
// explicitly zeroed and thus realized immediately (i.e. all pages are
// added to the process now instead of only when first accessed).
if (!base::UncheckedMalloc(size, &address))
return nullptr;
DCHECK(address);
memset(address, 0, size);
return address;
}
} // namespace
namespace base {
PersistentHistogramStorage::PersistentHistogramStorage(
StringPiece allocator_name,
StorageDirManagement storage_dir_management)
: storage_dir_management_(storage_dir_management) {
DCHECK(!allocator_name.empty());
DCHECK(IsStringASCII(allocator_name));
// This code may be executed before crash handling and/or OOM handling has
// been initialized for the process. Silently ignore a failed allocation
// (no metric persistence) rather that generating a crash that won't be
// caught/reported.
void* memory = AllocateLocalMemory(kAllocSize);
if (!memory)
return;
GlobalHistogramAllocator::CreateWithPersistentMemory(memory, kAllocSize, 0,
0, // No identifier.
allocator_name);
GlobalHistogramAllocator::Get()->CreateTrackingHistograms(allocator_name);
}
PersistentHistogramStorage::~PersistentHistogramStorage() {
PersistentHistogramAllocator* allocator = GlobalHistogramAllocator::Get();
if (!allocator)
return;
allocator->UpdateTrackingHistograms();
if (disabled_)
return;
// Stop if the storage base directory has not been properly set.
if (storage_base_dir_.empty()) {
LOG(ERROR)
<< "Could not write \"" << allocator->Name()
<< "\" persistent histograms to file as the storage base directory "
"is not properly set.";
return;
}
FilePath storage_dir = storage_base_dir_.AppendASCII(allocator->Name());
switch (storage_dir_management_) {
case StorageDirManagement::kCreate:
if (!CreateDirectory(storage_dir)) {
LOG(ERROR)
<< "Could not write \"" << allocator->Name()
<< "\" persistent histograms to file as the storage directory "
"cannot be created.";
return;
}
break;
case StorageDirManagement::kUseExisting:
if (!DirectoryExists(storage_dir)) {
// When the consumer of this class decides to use an existing storage
// directory, it should ensure the directory's existence if it's
// essential.
LOG(ERROR)
<< "Could not write \"" << allocator->Name()
<< "\" persistent histograms to file as the storage directory "
"does not exist.";
return;
}
break;
}
// Save data using the current time as the filename. The actual filename
// doesn't matter (so long as it ends with the correct extension) but this
// works as well as anything.
Time::Exploded exploded;
Time::Now().LocalExplode(&exploded);
const FilePath file_path =
storage_dir
.AppendASCII(StringPrintf("%04d%02d%02d%02d%02d%02d", exploded.year,
exploded.month, exploded.day_of_month,
exploded.hour, exploded.minute,
exploded.second))
.AddExtension(PersistentMemoryAllocator::kFileExtension);
StringPiece contents(static_cast<const char*>(allocator->data()),
allocator->used());
if (!ImportantFileWriter::WriteFileAtomically(file_path, contents)) {
LOG(ERROR) << "Persistent histograms fail to write to file: "
<< file_path.value();
}
}
} // namespace base