platform_bootable_recovery/fuse_sideload/include/fuse_provider.h
Tianjie Xu f6158eb918 Support starting fuse from a block map
Factor out a new function from ApplyFromSdcard that installs a package
from a local path. Inside this function, we start the fuse and choose the
type of data provider depending on the path string. And similar to the
existing logic, we treat the package as a block map if the path starts
with a '@'.

This is part of the effort to install larger than 2GiB packages on ILP32
devices.

Bug: 127071893
Test: Build a 32 bit sailfish and create a 3GiB OTA package. Sideload
the package, uncrypt and install the package from sdcard.

Change-Id: I328ea34fa530731acbce7554bfc3059313ad6ece
2019-06-20 13:53:40 -07:00

111 lines
3.4 KiB
C++

/*
* Copyright (C) 2019 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.
*/
#pragma once
#include <stdint.h>
#include <memory>
#include <string>
#include <android-base/unique_fd.h>
#include "otautil/rangeset.h"
// This is the base class to read data from source and provide the data to FUSE.
class FuseDataProvider {
public:
FuseDataProvider(uint64_t file_size, uint32_t block_size)
: file_size_(file_size), fuse_block_size_(block_size) {}
virtual ~FuseDataProvider() = default;
uint64_t file_size() const {
return file_size_;
}
uint32_t fuse_block_size() const {
return fuse_block_size_;
}
// Reads |fetch_size| bytes data starting from |start_block|. Puts the result in |buffer|.
virtual bool ReadBlockAlignedData(uint8_t* buffer, uint32_t fetch_size,
uint32_t start_block) const = 0;
virtual bool Valid() const = 0;
virtual void Close() {}
protected:
FuseDataProvider() = default;
// Size in bytes of the file to read.
uint64_t file_size_ = 0;
// Block size passed to the fuse, this is different from the block size of the block device.
uint32_t fuse_block_size_ = 0;
};
// This class reads data from a file.
class FuseFileDataProvider : public FuseDataProvider {
public:
FuseFileDataProvider(const std::string& path, uint32_t block_size);
static std::unique_ptr<FuseDataProvider> CreateFromFile(const std::string& path,
uint32_t block_size);
bool ReadBlockAlignedData(uint8_t* buffer, uint32_t fetch_size,
uint32_t start_block) const override;
bool Valid() const override {
return fd_ != -1;
}
void Close() override;
private:
// The underlying source to read data from.
android::base::unique_fd fd_;
};
// This class parses a block map and reads data from the underlying block device.
class FuseBlockDataProvider : public FuseDataProvider {
public:
// Constructs the fuse provider from the block map.
static std::unique_ptr<FuseDataProvider> CreateFromBlockMap(const std::string& block_map_path,
uint32_t fuse_block_size);
RangeSet ranges() const {
return ranges_;
}
bool ReadBlockAlignedData(uint8_t* buffer, uint32_t fetch_size,
uint32_t start_block) const override;
bool Valid() const override {
return fd_ != -1;
}
void Close() override;
private:
FuseBlockDataProvider(uint64_t file_size, uint32_t fuse_block_size, android::base::unique_fd&& fd,
uint32_t source_block_size, RangeSet ranges);
// The underlying block device to read data from.
android::base::unique_fd fd_;
// The block size of the source block device.
uint32_t source_block_size_;
// The block ranges from the source block device that consist of the file
RangeSet ranges_;
};