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// Copyright (C) 2017 The Android Open Source Project
//
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
// http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.
#include "protobuf_io.h"
#include "common/trace.h"
#include "serialize/arena_ptr.h"
#include <android-base/chrono_utils.h>
#include <android-base/logging.h>
#include <android-base/unique_fd.h>
#include <fcntl.h>
#include <sys/mman.h>
#include <sys/stat.h>
#include <sys/types.h>
#include <unistd.h>
#include <utils/Trace.h>
#include "google/protobuf/io/zero_copy_stream_impl_lite.h"
#include "system/iorap/src/serialize/TraceFile.pb.h"
namespace iorap {
namespace serialize {
ArenaPtr<proto::TraceFile> ProtobufIO::Open(std::string file_path) {
// TODO: file a bug about this.
// Note: can't use {} here, clang think it's narrowing from long->int.
android::base::unique_fd fd(TEMP_FAILURE_RETRY(::open(file_path.c_str(), O_RDONLY)));
if (fd.get() < 0) {
PLOG(DEBUG) << "ProtobufIO: open failed: " << file_path;
return nullptr;
}
return Open(fd.get(), file_path.c_str());
}
ArenaPtr<proto::TraceFile> ProtobufIO::Open(int fd, const char* file_path) {
ScopedFormatTrace atrace_protobuf_io_open(ATRACE_TAG_ACTIVITY_MANAGER,
"ProtobufIO::Open %s",
file_path);
android::base::Timer timer{};
struct stat buf;
if (fstat(fd, /*out*/&buf) < 0) {
PLOG(ERROR) << "ProtobufIO: open error, fstat failed: " << file_path;
return nullptr;
}
// XX: off64_t for stat::st_size ?
// Using the mmap appears to be the only way to do zero-copy with protobuf lite.
void* data = mmap(/*addr*/nullptr,
buf.st_size,
PROT_READ, MAP_SHARED | MAP_POPULATE,
fd,
/*offset*/0);
if (data == nullptr) {
PLOG(ERROR) << "ProtobufIO: open error, mmap failed: " << file_path;
return nullptr;
}
ArenaPtr<proto::TraceFile> protobuf_trace_file = ArenaPtr<proto::TraceFile>::Make();
if (protobuf_trace_file == nullptr) {
LOG(ERROR) << "ProtobufIO: open error, failed to create arena: " << file_path;
return nullptr;
}
google::protobuf::io::ArrayInputStream protobuf_input_stream{data, static_cast<int>(buf.st_size)};
if (!protobuf_trace_file->ParseFromZeroCopyStream(/*in*/&protobuf_input_stream)) {
// XX: Does protobuf on android already have the right LogHandler ?
LOG(ERROR) << "ProtobufIO: open error, protobuf parsing failed: " << file_path;
return nullptr;
}
if (munmap(data, buf.st_size) < 0) {
PLOG(WARNING) << "ProtobufIO: open problem, munmap failed, possibly memory leak? "
<< file_path;
}
LOG(VERBOSE) << "ProtobufIO: open succeeded: " << file_path << ", duration: " << timer;
return protobuf_trace_file;
}
iorap::expected<size_t /*bytes written*/, int /*errno*/> ProtobufIO::WriteFully(
const ::google::protobuf::MessageLite& message,
std::string_view file_path) {
std::string str{file_path};
android::base::unique_fd fd(TEMP_FAILURE_RETRY(
::open(str.c_str(),
O_CREAT | O_TRUNC | O_RDWR,
S_IRUSR | S_IWUSR | S_IRGRP | S_IWGRP))); // ugo: rw-rw----
if (fd.get() < 0) {
int err = errno;
PLOG(ERROR) << "ProtobufIO: open failed: " << file_path;
return unexpected{err};
}
return WriteFully(message, fd.get(), file_path);
}
iorap::expected<size_t /*bytes written*/, int /*errno*/> ProtobufIO::WriteFully(
const ::google::protobuf::MessageLite& message,
int fd,
std::string_view file_path) {
int byte_size = message.ByteSize();
if (byte_size < 0) {
DCHECK(false) << "Invalid protobuf size: " << byte_size;
LOG(ERROR) << "ProtobufIO: Invalid protobuf size: " << byte_size;
return unexpected{EDOM};
}
size_t serialized_size = static_cast<size_t>(byte_size);
// Change the file to be exactly the length of the protobuf.
if (ftruncate(fd, static_cast<off_t>(serialized_size)) < 0) {
int err = errno;
PLOG(ERROR) << "ProtobufIO: ftruncate (size=" << serialized_size << ") failed";
return unexpected{err};
}
// Using the mmap appears to be the only way to do zero-copy with protobuf lite.
void* data = mmap(/*addr*/nullptr,
serialized_size,
PROT_WRITE,
MAP_SHARED,
fd,
/*offset*/0);
if (data == nullptr) {
int err = errno;
PLOG(ERROR) << "ProtobufIO: mmap failed: " << file_path;
return unexpected{err};
}
// Zero-copy write from protobuf to file via memory-map.
::google::protobuf::io::ArrayOutputStream output_stream{data, byte_size};
if (!message.SerializeToZeroCopyStream(/*inout*/&output_stream)) {
// This should never happen since we pre-allocated the file and memory map to be large
// enough to store the full protobuf.
DCHECK(false) << "ProtobufIO:: SerializeToZeroCopyStream failed despite precalculating size";
LOG(ERROR) << "ProtobufIO: SerializeToZeroCopyStream failed";
return unexpected{EXFULL};
}
// Guarantee that changes are written back prior to munmap.
if (msync(data, static_cast<size_t>(serialized_size), MS_SYNC) < 0) {
int err = errno;
PLOG(ERROR) << "ProtobufIO: msync failed";
return unexpected{err};
}
if (munmap(data, serialized_size) < 0) {
PLOG(WARNING) << "ProtobufIO: munmap failed, possibly memory leak? "
<< file_path;
}
return serialized_size;
}
} // namespace serialize
} // namespace iorap
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