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/*
* Copyright (C) 2015 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.
*/
#ifndef AAPT_IO_DATA_H
#define AAPT_IO_DATA_H
#include <memory>
#include "android-base/macros.h"
#include "utils/FileMap.h"
#include "io/Io.h"
namespace aapt {
namespace io {
// Interface for a block of contiguous memory. An instance of this interface owns the data.
class IData : public InputStream {
public:
virtual ~IData() = default;
virtual const void* data() const = 0;
virtual size_t size() const = 0;
};
class DataSegment : public IData {
public:
explicit DataSegment(std::unique_ptr<IData> data, size_t offset, size_t len)
: data_(std::move(data)), offset_(offset), len_(len), next_read_(offset) {}
virtual ~DataSegment() = default;
const void* data() const override {
return static_cast<const uint8_t*>(data_->data()) + offset_;
}
size_t size() const override { return len_; }
bool Next(const void** data, size_t* size) override {
if (next_read_ == offset_ + len_) {
return false;
}
*data = static_cast<const uint8_t*>(data_->data()) + next_read_;
*size = len_ - (next_read_ - offset_);
next_read_ = offset_ + len_;
return true;
}
void BackUp(size_t count) override {
if (count > next_read_ - offset_) {
next_read_ = offset_;
} else {
next_read_ -= count;
}
}
bool CanRewind() const override { return true; }
bool Rewind() override {
next_read_ = offset_;
return true;
}
size_t ByteCount() const override { return next_read_ - offset_; }
bool HadError() const override { return false; }
private:
DISALLOW_COPY_AND_ASSIGN(DataSegment);
std::unique_ptr<IData> data_;
size_t offset_;
size_t len_;
size_t next_read_;
};
// Implementation of IData that exposes a memory mapped file.
// The mmapped file is owned by this object.
class MmappedData : public IData {
public:
explicit MmappedData(android::FileMap&& map) : map_(std::forward<android::FileMap>(map)) {}
virtual ~MmappedData() = default;
const void* data() const override { return map_.getDataPtr(); }
size_t size() const override { return map_.getDataLength(); }
bool Next(const void** data, size_t* size) override {
if (next_read_ == map_.getDataLength()) {
return false;
}
*data = reinterpret_cast<const uint8_t*>(map_.getDataPtr()) + next_read_;
*size = map_.getDataLength() - next_read_;
next_read_ = map_.getDataLength();
return true;
}
void BackUp(size_t count) override {
if (count > next_read_) {
next_read_ = 0;
} else {
next_read_ -= count;
}
}
bool CanRewind() const override { return true; }
bool Rewind() override {
next_read_ = 0;
return true;
}
size_t ByteCount() const override { return next_read_; }
bool HadError() const override { return false; }
private:
DISALLOW_COPY_AND_ASSIGN(MmappedData);
android::FileMap map_;
size_t next_read_ = 0;
};
// Implementation of IData that exposes a block of memory that was malloc'ed (new'ed).
// The memory is owned by this object.
class MallocData : public IData {
public:
MallocData(std::unique_ptr<const uint8_t[]> data, size_t size)
: data_(std::move(data)), size_(size) {}
virtual ~MallocData() = default;
const void* data() const override { return data_.get(); }
size_t size() const override { return size_; }
bool Next(const void** data, size_t* size) override {
if (next_read_ == size_) {
return false;
}
*data = data_.get() + next_read_;
*size = size_ - next_read_;
next_read_ = size_;
return true;
}
void BackUp(size_t count) override {
if (count > next_read_) {
next_read_ = 0;
} else {
next_read_ -= count;
}
}
bool CanRewind() const override { return true; }
bool Rewind() override {
next_read_ = 0;
return true;
}
size_t ByteCount() const override { return next_read_; }
bool HadError() const override { return false; }
private:
DISALLOW_COPY_AND_ASSIGN(MallocData);
std::unique_ptr<const uint8_t[]> data_;
size_t size_;
size_t next_read_ = 0;
};
// When mmap fails because the file has length 0, we use the EmptyData to simulate data of length 0.
class EmptyData : public IData {
public:
virtual ~EmptyData() = default;
const void* data() const override {
static const uint8_t d = 0;
return &d;
}
size_t size() const override { return 0u; }
bool Next(const void** /*data*/, size_t* /*size*/) override { return false; }
void BackUp(size_t /*count*/) override {}
bool CanRewind() const override { return true; }
bool Rewind() override { return true; }
size_t ByteCount() const override { return 0u; }
bool HadError() const override { return false; }
};
} // namespace io
} // namespace aapt
#endif /* AAPT_IO_DATA_H */