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/*
* Copyright (C) 2012 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 _LIBSPARSE_SPARSE_H_
#define _LIBSPARSE_SPARSE_H_
#include <stdbool.h>
#include <stdint.h>
struct sparse_file;
/**
* sparse_file_new - create a new sparse file cookie
*
* @block_size - minimum size of a chunk
* @len - size of the expanded sparse file.
*
* Creates a new sparse_file cookie that can be used to associate data
* blocks. Can later be written to a file with a variety of options.
* block_size specifies the minimum size of a chunk in the file. The maximum
* size of the file is 2**32 * block_size (16TB for 4k block size).
*
* Returns the sparse file cookie, or NULL on error.
*/
struct sparse_file *sparse_file_new(unsigned int block_size, int64_t len);
/**
* sparse_file_destroy - destroy a sparse file cookie
*
* @s - sparse file cookie
*
* Destroys a sparse file cookie. After destroy, all memory passed in to
* sparse_file_add_data can be freed by the caller
*/
void sparse_file_destroy(struct sparse_file *s);
/**
* sparse_file_add_data - associate a data chunk with a sparse file
*
* @s - sparse file cookie
* @data - pointer to data block
* @len - length of the data block
* @block - offset in blocks into the sparse file to place the data chunk
*
* Associates a data chunk with a sparse file cookie. The region
* [block * block_size : block * block_size + len) must not already be used in
* the sparse file. If len is not a multiple of the block size the data
* will be padded with zeros.
*
* The data pointer must remain valid until the sparse file is closed or the
* data block is removed from the sparse file.
*
* Returns 0 on success, negative errno on error.
*/
int sparse_file_add_data(struct sparse_file *s,
void *data, unsigned int len, unsigned int block);
/**
* sparse_file_add_fill - associate a fill chunk with a sparse file
*
* @s - sparse file cookie
* @fill_val - 32 bit fill data
* @len - length of the fill block
* @block - offset in blocks into the sparse file to place the fill chunk
*
* Associates a chunk filled with fill_val with a sparse file cookie.
* The region [block * block_size : block * block_size + len) must not already
* be used in the sparse file. If len is not a multiple of the block size the
* data will be padded with zeros.
*
* Returns 0 on success, negative errno on error.
*/
int sparse_file_add_fill(struct sparse_file *s,
uint32_t fill_val, unsigned int len, unsigned int block);
/**
* sparse_file_add_file - associate a chunk of a file with a sparse file
*
* @s - sparse file cookie
* @filename - filename of the file to be copied
* @file_offset - offset into the copied file
* @len - length of the copied block
* @block - offset in blocks into the sparse file to place the file chunk
*
* Associates a chunk of an existing file with a sparse file cookie.
* The region [block * block_size : block * block_size + len) must not already
* be used in the sparse file. If len is not a multiple of the block size the
* data will be padded with zeros.
*
* Allows adding large amounts of data to a sparse file without needing to keep
* it all mapped. File size is limited by available virtual address space,
* exceptionally large files may need to be added in multiple chunks.
*
* Returns 0 on success, negative errno on error.
*/
int sparse_file_add_file(struct sparse_file *s,
const char *filename, int64_t file_offset, unsigned int len,
unsigned int block);
/**
* sparse_file_write - write a sparse file to a file
*
* @s - sparse file cookie
* @fd - file descriptor to write to
* @gz - write a gzipped file
* @sparse - write in the Android sparse file format
* @crc - append a crc chunk
*
* Writes a sparse file to a file. If gz is true, the data will be passed
* through zlib. If sparse is true, the file will be written in the Android
* sparse file format. If sparse is false, the file will be written by seeking
* over unused chunks, producing a smaller file if the filesystem supports
* sparse files. If crc is true, the crc of the expanded data will be
* calculated and appended in a crc chunk.
*
* Returns 0 on success, negative errno on error.
*/
int sparse_file_write(struct sparse_file *s, int fd, bool gz, bool sparse,
bool crc);
#endif
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