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// Copyright 2013 The Flutter 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 "flutter/fml/message.h"
#include "flutter/fml/logging.h"
namespace fml {
size_t MessageSerializable::GetSerializableTag() const {
return 0;
};
Message::Message() = default;
Message::~Message() = default;
static uint32_t NextPowerOfTwoSize(uint32_t x) {
if (x == 0) {
return 1;
}
--x;
x |= x >> 1;
x |= x >> 2;
x |= x >> 4;
x |= x >> 8;
x |= x >> 16;
return x + 1;
}
const uint8_t* Message::GetBuffer() const {
return buffer_;
}
size_t Message::GetBufferSize() const {
return buffer_length_;
}
size_t Message::GetDataLength() const {
return data_length_;
}
size_t Message::GetSizeRead() const {
return size_read_;
}
bool Message::Reserve(size_t size) {
if (buffer_length_ >= size) {
return true;
}
return Resize(NextPowerOfTwoSize(size));
}
bool Message::Resize(size_t size) {
if (buffer_ == nullptr) {
// This is the initial resize where we have no previous buffer.
FML_DCHECK(buffer_length_ == 0);
void* buffer = ::malloc(size);
const bool success = buffer != nullptr;
if (success) {
buffer_ = static_cast<uint8_t*>(buffer);
buffer_length_ = size;
}
return success;
}
FML_DCHECK(size > buffer_length_);
void* resized = ::realloc(buffer_, size);
const bool success = resized != nullptr;
// In case of failure, the input buffer to realloc is still valid.
if (success) {
buffer_ = static_cast<uint8_t*>(resized);
buffer_length_ = size;
}
return success;
}
uint8_t* Message::PrepareEncode(size_t size) {
if (!Reserve(data_length_ + size)) {
return nullptr;
}
auto old_length = data_length_;
data_length_ += size;
return buffer_ + old_length;
}
uint8_t* Message::PrepareDecode(size_t size) {
if ((size + size_read_) > buffer_length_) {
return nullptr;
}
auto* buffer = buffer_ + size_read_;
size_read_ += size;
return buffer;
}
void Message::ResetRead() {
size_read_ = 0;
}
} // namespace fml