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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_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 fd 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.
+ *
+ * The fd must remain open until the sparse file is closed or the fd block is
+ * removed from the sparse file.
+ *
+ * Returns 0 on success, negative errno on error.
+ */
+int sparse_file_add_fd(struct sparse_file *s,
+		int fd, 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);
+
+/**
+ * sparse_file_len - return the length of a sparse file if written to disk
+ *
+ * @s - sparse file cookie
+ * @sparse - write in the Android sparse file format
+ * @crc - append a crc chunk
+ *
+ * Returns the size a sparse file would be on disk if it were written in the
+ * specified format.  If sparse is true, this is the size of the data in the
+ * sparse format.  If sparse is false, this is the size of the normal
+ * non-sparse file.
+ */
+int64_t sparse_file_len(struct sparse_file *s, bool sparse, bool crc);
+
+/**
+ * sparse_file_callback - call a callback for blocks in sparse file
+ *
+ * @s - sparse file cookie
+ * @sparse - write in the Android sparse file format
+ * @crc - append a crc chunk
+ * @write - function to call for each block
+ * @priv - value that will be passed as the first argument to write
+ *
+ * Writes a sparse file by calling a callback function.  If sparse is true, the
+ * file will be written in the Android sparse file format.  If crc is true, the
+ * crc of the expanded data will be calculated and appended in a crc chunk.
+ * The callback 'write' will be called with data and length for each data,
+ * and with data==NULL to skip over a region (only used for non-sparse format).
+ * The callback should return negative on error, 0 on success.
+ *
+ * Returns 0 on success, negative errno on error.
+ */
+int sparse_file_callback(struct sparse_file *s, bool sparse, bool crc,
+		int (*write)(void *priv, const void *data, int len), void *priv);
+
+/**
+ * sparse_file_read - read a file into a sparse file cookie
+ *
+ * @s - sparse file cookie
+ * @fd - file descriptor to read from
+ * @sparse - read a file in the Android sparse file format
+ * @crc - verify the crc of a file in the Android sparse file format
+ *
+ * Reads a file into a sparse file cookie.  If sparse is true, the file is
+ * assumed to be in the Android sparse file format.  If sparse is false, the
+ * file will be sparsed by looking for block aligned chunks of all zeros or
+ * another 32 bit value.  If crc is true, the crc of the sparse file will be
+ * verified.
+ *
+ * Returns 0 on success, negative errno on error.
+ */
+int sparse_file_read(struct sparse_file *s, int fd, bool sparse, bool crc);
+
+/**
+ * sparse_file_import - import an existing sparse file
+ *
+ * @s - sparse file cookie
+ * @verbose - print verbose errors while reading the sparse file
+ * @crc - verify the crc of a file in the Android sparse file format
+ *
+ * Reads an existing sparse file into a sparse file cookie, recreating the same
+ * sparse cookie that was used to write it.  If verbose is true, prints verbose
+ * errors when the sparse file is formatted incorrectly.
+ *
+ * Returns a new sparse file cookie on success, NULL on error.
+ */
+struct sparse_file *sparse_file_import(int fd, bool verbose, bool crc);
+
+/**
+ * sparse_file_import_auto - import an existing sparse or normal file
+ *
+ * @fd - file descriptor to read from
+ * @crc - verify the crc of a file in the Android sparse file format
+ *
+ * Reads an existing sparse or normal file into a sparse file cookie.
+ * Attempts to determine if the file is sparse or not by looking for the sparse
+ * file magic number in the first 4 bytes.  If the file is not sparse, the file
+ * will be sparsed by looking for block aligned chunks of all zeros or another
+ * 32 bit value.  If crc is true, the crc of the sparse file will be verified.
+ *
+ * Returns a new sparse file cookie on success, NULL on error.
+ */
+struct sparse_file *sparse_file_import_auto(int fd, bool crc);
+
+/** sparse_file_resparse - rechunk an existing sparse file into smaller files
+ *
+ * @in_s - sparse file cookie of the existing sparse file
+ * @max_len - maximum file size
+ * @out_s - array of sparse file cookies
+ * @out_s_count - size of out_s array
+ *
+ * Splits chunks of an existing sparse file into smaller sparse files such that
+ * each sparse file is less than max_len.  Returns the number of sparse_files
+ * that would have been written to out_s if out_s were big enough.
+ */
+int sparse_file_resparse(struct sparse_file *in_s, unsigned int max_len,
+		struct sparse_file **out_s, int out_s_count);
+
+/**
+ * sparse_file_verbose - set a sparse file cookie to print verbose errors
+ *
+ * @s - sparse file cookie
+ *
+ * Print verbose sparse file errors whenever using the sparse file cookie.
+ */
+void sparse_file_verbose(struct sparse_file *s);
+
+/**
+ * sparse_print_verbose - function called to print verbose errors
+ *
+ * By default, verbose errors will print to standard error.
+ * sparse_print_verbose may be overridden to log verbose errors somewhere else.
+ *
+ */
+extern void (*sparse_print_verbose)(const char *fmt, ...);
+
+#endif