| Current File : //usr/include/lzma/index.h |
/**
* \file lzma/index.h
* \brief Handling of .xz Index and related information
*/
/*
* Author: Lasse Collin
*
* This file has been put into the public domain.
* You can do whatever you want with this file.
*
* See ../lzma.h for information about liblzma as a whole.
*/
#ifndef LZMA_H_INTERNAL
# error Never include this file directly. Use <lzma.h> instead.
#endif
/**
* \brief Opaque data type to hold the Index(es) and other information
*
* lzma_index often holds just one .xz Index and possibly the Stream Flags
* of the same Stream and size of the Stream Padding field. However,
* multiple lzma_indexes can be concatenated with lzma_index_cat() and then
* there may be information about multiple Streams in the same lzma_index.
*
* Notes about thread safety: Only one thread may modify lzma_index at
* a time. All functions that take non-const pointer to lzma_index
* modify it. As long as no thread is modifying the lzma_index, getting
* information from the same lzma_index can be done from multiple threads
* at the same time with functions that take a const pointer to
* lzma_index or use lzma_index_iter. The same iterator must be used
* only by one thread at a time, of course, but there can be as many
* iterators for the same lzma_index as needed.
*/
typedef struct lzma_index_s lzma_index;
/**
* \brief Iterator to get information about Blocks and Streams
*/
typedef struct {
struct {
/**
* \brief Pointer to Stream Flags
*
* This is NULL if Stream Flags have not been set for
* this Stream with lzma_index_stream_flags().
*/
const lzma_stream_flags *flags;
const void *reserved_ptr1;
const void *reserved_ptr2;
const void *reserved_ptr3;
/**
* \brief Stream number in the lzma_index
*
* The first Stream is 1.
*/
lzma_vli number;
/**
* \brief Number of Blocks in the Stream
*
* If this is zero, the block structure below has
* undefined values.
*/
lzma_vli block_count;
/**
* \brief Compressed start offset of this Stream
*
* The offset is relative to the beginning of the lzma_index
* (i.e. usually the beginning of the .xz file).
*/
lzma_vli compressed_offset;
/**
* \brief Uncompressed start offset of this Stream
*
* The offset is relative to the beginning of the lzma_index
* (i.e. usually the beginning of the .xz file).
*/
lzma_vli uncompressed_offset;
/**
* \brief Compressed size of this Stream
*
* This includes all headers except the possible
* Stream Padding after this Stream.
*/
lzma_vli compressed_size;
/**
* \brief Uncompressed size of this Stream
*/
lzma_vli uncompressed_size;
/**
* \brief Size of Stream Padding after this Stream
*
* If it hasn't been set with lzma_index_stream_padding(),
* this defaults to zero. Stream Padding is always
* a multiple of four bytes.
*/
lzma_vli padding;
lzma_vli reserved_vli1;
lzma_vli reserved_vli2;
lzma_vli reserved_vli3;
lzma_vli reserved_vli4;
} stream;
struct {
/**
* \brief Block number in the file
*
* The first Block is 1.
*/
lzma_vli number_in_file;
/**
* \brief Compressed start offset of this Block
*
* This offset is relative to the beginning of the
* lzma_index (i.e. usually the beginning of the .xz file).
* Normally this is where you should seek in the .xz file
* to start decompressing this Block.
*/
lzma_vli compressed_file_offset;
/**
* \brief Uncompressed start offset of this Block
*
* This offset is relative to the beginning of the lzma_index
* (i.e. usually the beginning of the .xz file).
*
* When doing random-access reading, it is possible that
* the target offset is not exactly at Block boundary. One
* will need to compare the target offset against
* uncompressed_file_offset or uncompressed_stream_offset,
* and possibly decode and throw away some amount of data
* before reaching the target offset.
*/
lzma_vli uncompressed_file_offset;
/**
* \brief Block number in this Stream
*
* The first Block is 1.
*/
lzma_vli number_in_stream;
/**
* \brief Compressed start offset of this Block
*
* This offset is relative to the beginning of the Stream
* containing this Block.
*/
lzma_vli compressed_stream_offset;
/**
* \brief Uncompressed start offset of this Block
*
* This offset is relative to the beginning of the Stream
* containing this Block.
*/
lzma_vli uncompressed_stream_offset;
/**
* \brief Uncompressed size of this Block
*
* You should pass this to the Block decoder if you will
* decode this Block. It will allow the Block decoder to
* validate the uncompressed size.
*/
lzma_vli uncompressed_size;
/**
* \brief Unpadded size of this Block
*
* You should pass this to the Block decoder if you will
* decode this Block. It will allow the Block decoder to
* validate the unpadded size.
*/
lzma_vli unpadded_size;
/**
* \brief Total compressed size
*
* This includes all headers and padding in this Block.
* This is useful if you need to know how many bytes
* the Block decoder will actually read.
*/
lzma_vli total_size;
lzma_vli reserved_vli1;
lzma_vli reserved_vli2;
lzma_vli reserved_vli3;
lzma_vli reserved_vli4;
const void *reserved_ptr1;
const void *reserved_ptr2;
const void *reserved_ptr3;
const void *reserved_ptr4;
} block;
/*
* Internal data which is used to store the state of the iterator.
* The exact format may vary between liblzma versions, so don't
* touch these in any way.
*/
union {
const void *p;
size_t s;
lzma_vli v;
} internal[6];
} lzma_index_iter;
/**
* \brief Operation mode for lzma_index_iter_next()
*/
typedef enum {
LZMA_INDEX_ITER_ANY = 0,
/**<
* \brief Get the next Block or Stream
*
* Go to the next Block if the current Stream has at least
* one Block left. Otherwise go to the next Stream even if
* it has no Blocks. If the Stream has no Blocks
* (lzma_index_iter.stream.block_count == 0),
* lzma_index_iter.block will have undefined values.
*/
LZMA_INDEX_ITER_STREAM = 1,
/**<
* \brief Get the next Stream
*
* Go to the next Stream even if the current Stream has
* unread Blocks left. If the next Stream has at least one
* Block, the iterator will point to the first Block.
* If there are no Blocks, lzma_index_iter.block will have
* undefined values.
*/
LZMA_INDEX_ITER_BLOCK = 2,
/**<
* \brief Get the next Block
*
* Go to the next Block if the current Stream has at least
* one Block left. If the current Stream has no Blocks left,
* the next Stream with at least one Block is located and
* the iterator will be made to point to the first Block of
* that Stream.
*/
LZMA_INDEX_ITER_NONEMPTY_BLOCK = 3
/**<
* \brief Get the next non-empty Block
*
* This is like LZMA_INDEX_ITER_BLOCK except that it will
* skip Blocks whose Uncompressed Size is zero.
*/
} lzma_index_iter_mode;
/**
* \brief Calculate memory usage of lzma_index
*
* On disk, the size of the Index field depends on both the number of Records
* stored and how big values the Records store (due to variable-length integer
* encoding). When the Index is kept in lzma_index structure, the memory usage
* depends only on the number of Records/Blocks stored in the Index(es), and
* in case of concatenated lzma_indexes, the number of Streams. The size in
* RAM is almost always significantly bigger than in the encoded form on disk.
*
* This function calculates an approximate amount of memory needed hold
* the given number of Streams and Blocks in lzma_index structure. This
* value may vary between CPU architectures and also between liblzma versions
* if the internal implementation is modified.
*/
extern LZMA_API(uint64_t) lzma_index_memusage(
lzma_vli streams, lzma_vli blocks) lzma_nothrow;
/**
* \brief Calculate the memory usage of an existing lzma_index
*
* This is a shorthand for lzma_index_memusage(lzma_index_stream_count(i),
* lzma_index_block_count(i)).
*/
extern LZMA_API(uint64_t) lzma_index_memused(const lzma_index *i)
lzma_nothrow;
/**
* \brief Allocate and initialize a new lzma_index structure
*
* \return On success, a pointer to an empty initialized lzma_index is
* returned. If allocation fails, NULL is returned.
*/
extern LZMA_API(lzma_index *) lzma_index_init(const lzma_allocator *allocator)
lzma_nothrow;
/**
* \brief Deallocate lzma_index
*
* If i is NULL, this does nothing.
*/
extern LZMA_API(void) lzma_index_end(
lzma_index *i, const lzma_allocator *allocator) lzma_nothrow;
/**
* \brief Add a new Block to lzma_index
*
* \param i Pointer to a lzma_index structure
* \param allocator Pointer to lzma_allocator, or NULL to
* use malloc()
* \param unpadded_size Unpadded Size of a Block. This can be
* calculated with lzma_block_unpadded_size()
* after encoding or decoding the Block.
* \param uncompressed_size Uncompressed Size of a Block. This can be
* taken directly from lzma_block structure
* after encoding or decoding the Block.
*
* Appending a new Block does not invalidate iterators. For example,
* if an iterator was pointing to the end of the lzma_index, after
* lzma_index_append() it is possible to read the next Block with
* an existing iterator.
*
* \return - LZMA_OK
* - LZMA_MEM_ERROR
* - LZMA_DATA_ERROR: Compressed or uncompressed size of the
* Stream or size of the Index field would grow too big.
* - LZMA_PROG_ERROR
*/
extern LZMA_API(lzma_ret) lzma_index_append(
lzma_index *i, const lzma_allocator *allocator,
lzma_vli unpadded_size, lzma_vli uncompressed_size)
lzma_nothrow lzma_attr_warn_unused_result;
/**
* \brief Set the Stream Flags
*
* Set the Stream Flags of the last (and typically the only) Stream
* in lzma_index. This can be useful when reading information from the
* lzma_index, because to decode Blocks, knowing the integrity check type
* is needed.
*
* The given Stream Flags are copied into internal preallocated structure
* in the lzma_index, thus the caller doesn't need to keep the *stream_flags
* available after calling this function.
*
* \return - LZMA_OK
* - LZMA_OPTIONS_ERROR: Unsupported stream_flags->version.
* - LZMA_PROG_ERROR
*/
extern LZMA_API(lzma_ret) lzma_index_stream_flags(
lzma_index *i, const lzma_stream_flags *stream_flags)
lzma_nothrow lzma_attr_warn_unused_result;
/**
* \brief Get the types of integrity Checks
*
* If lzma_index_stream_flags() is used to set the Stream Flags for
* every Stream, lzma_index_checks() can be used to get a bitmask to
* indicate which Check types have been used. It can be useful e.g. if
* showing the Check types to the user.
*
* The bitmask is 1 << check_id, e.g. CRC32 is 1 << 1 and SHA-256 is 1 << 10.
*/
extern LZMA_API(uint32_t) lzma_index_checks(const lzma_index *i)
lzma_nothrow lzma_attr_pure;
/**
* \brief Set the amount of Stream Padding
*
* Set the amount of Stream Padding of the last (and typically the only)
* Stream in the lzma_index. This is needed when planning to do random-access
* reading within multiple concatenated Streams.
*
* By default, the amount of Stream Padding is assumed to be zero bytes.
*
* \return - LZMA_OK
* - LZMA_DATA_ERROR: The file size would grow too big.
* - LZMA_PROG_ERROR
*/
extern LZMA_API(lzma_ret) lzma_index_stream_padding(
lzma_index *i, lzma_vli stream_padding)
lzma_nothrow lzma_attr_warn_unused_result;
/**
* \brief Get the number of Streams
*/
extern LZMA_API(lzma_vli) lzma_index_stream_count(const lzma_index *i)
lzma_nothrow lzma_attr_pure;
/**
* \brief Get the number of Blocks
*
* This returns the total number of Blocks in lzma_index. To get number
* of Blocks in individual Streams, use lzma_index_iter.
*/
extern LZMA_API(lzma_vli) lzma_index_block_count(const lzma_index *i)
lzma_nothrow lzma_attr_pure;
/**
* \brief Get the size of the Index field as bytes
*
* This is needed to verify the Backward Size field in the Stream Footer.
*/
extern LZMA_API(lzma_vli) lzma_index_size(const lzma_index *i)
lzma_nothrow lzma_attr_pure;
/**
* \brief Get the total size of the Stream
*
* If multiple lzma_indexes have been combined, this works as if the Blocks
* were in a single Stream. This is useful if you are going to combine
* Blocks from multiple Streams into a single new Stream.
*/
extern LZMA_API(lzma_vli) lzma_index_stream_size(const lzma_index *i)
lzma_nothrow lzma_attr_pure;
/**
* \brief Get the total size of the Blocks
*
* This doesn't include the Stream Header, Stream Footer, Stream Padding,
* or Index fields.
*/
extern LZMA_API(lzma_vli) lzma_index_total_size(const lzma_index *i)
lzma_nothrow lzma_attr_pure;
/**
* \brief Get the total size of the file
*
* When no lzma_indexes have been combined with lzma_index_cat() and there is
* no Stream Padding, this function is identical to lzma_index_stream_size().
* If multiple lzma_indexes have been combined, this includes also the headers
* of each separate Stream and the possible Stream Padding fields.
*/
extern LZMA_API(lzma_vli) lzma_index_file_size(const lzma_index *i)
lzma_nothrow lzma_attr_pure;
/**
* \brief Get the uncompressed size of the file
*/
extern LZMA_API(lzma_vli) lzma_index_uncompressed_size(const lzma_index *i)
lzma_nothrow lzma_attr_pure;
/**
* \brief Initialize an iterator
*
* \param iter Pointer to a lzma_index_iter structure
* \param i lzma_index to which the iterator will be associated
*
* This function associates the iterator with the given lzma_index, and calls
* lzma_index_iter_rewind() on the iterator.
*
* This function doesn't allocate any memory, thus there is no
* lzma_index_iter_end(). The iterator is valid as long as the
* associated lzma_index is valid, that is, until lzma_index_end() or
* using it as source in lzma_index_cat(). Specifically, lzma_index doesn't
* become invalid if new Blocks are added to it with lzma_index_append() or
* if it is used as the destination in lzma_index_cat().
*
* It is safe to make copies of an initialized lzma_index_iter, for example,
* to easily restart reading at some particular position.
*/
extern LZMA_API(void) lzma_index_iter_init(
lzma_index_iter *iter, const lzma_index *i) lzma_nothrow;
/**
* \brief Rewind the iterator
*
* Rewind the iterator so that next call to lzma_index_iter_next() will
* return the first Block or Stream.
*/
extern LZMA_API(void) lzma_index_iter_rewind(lzma_index_iter *iter)
lzma_nothrow;
/**
* \brief Get the next Block or Stream
*
* \param iter Iterator initialized with lzma_index_iter_init()
* \param mode Specify what kind of information the caller wants
* to get. See lzma_index_iter_mode for details.
*
* \return If next Block or Stream matching the mode was found, *iter
* is updated and this function returns false. If no Block or
* Stream matching the mode is found, *iter is not modified
* and this function returns true. If mode is set to an unknown
* value, *iter is not modified and this function returns true.
*/
extern LZMA_API(lzma_bool) lzma_index_iter_next(
lzma_index_iter *iter, lzma_index_iter_mode mode)
lzma_nothrow lzma_attr_warn_unused_result;
/**
* \brief Locate a Block
*
* If it is possible to seek in the .xz file, it is possible to parse
* the Index field(s) and use lzma_index_iter_locate() to do random-access
* reading with granularity of Block size.
*
* \param iter Iterator that was earlier initialized with
* lzma_index_iter_init().
* \param target Uncompressed target offset which the caller would
* like to locate from the Stream
*
* If the target is smaller than the uncompressed size of the Stream (can be
* checked with lzma_index_uncompressed_size()):
* - Information about the Stream and Block containing the requested
* uncompressed offset is stored into *iter.
* - Internal state of the iterator is adjusted so that
* lzma_index_iter_next() can be used to read subsequent Blocks or Streams.
* - This function returns false.
*
* If target is greater than the uncompressed size of the Stream, *iter
* is not modified, and this function returns true.
*/
extern LZMA_API(lzma_bool) lzma_index_iter_locate(
lzma_index_iter *iter, lzma_vli target) lzma_nothrow;
/**
* \brief Concatenate lzma_indexes
*
* Concatenating lzma_indexes is useful when doing random-access reading in
* multi-Stream .xz file, or when combining multiple Streams into single
* Stream.
*
* \param dest lzma_index after which src is appended
* \param src lzma_index to be appended after dest. If this
* function succeeds, the memory allocated for src
* is freed or moved to be part of dest, and all
* iterators pointing to src will become invalid.
* \param allocator Custom memory allocator; can be NULL to use
* malloc() and free().
*
* \return - LZMA_OK: lzma_indexes were concatenated successfully.
* src is now a dangling pointer.
* - LZMA_DATA_ERROR: *dest would grow too big.
* - LZMA_MEM_ERROR
* - LZMA_PROG_ERROR
*/
extern LZMA_API(lzma_ret) lzma_index_cat(lzma_index *dest, lzma_index *src,
const lzma_allocator *allocator)
lzma_nothrow lzma_attr_warn_unused_result;
/**
* \brief Duplicate lzma_index
*
* \return A copy of the lzma_index, or NULL if memory allocation failed.
*/
extern LZMA_API(lzma_index *) lzma_index_dup(
const lzma_index *i, const lzma_allocator *allocator)
lzma_nothrow lzma_attr_warn_unused_result;
/**
* \brief Initialize .xz Index encoder
*
* \param strm Pointer to properly prepared lzma_stream
* \param i Pointer to lzma_index which should be encoded.
*
* The valid `action' values for lzma_code() are LZMA_RUN and LZMA_FINISH.
* It is enough to use only one of them (you can choose freely).
*
* \return - LZMA_OK: Initialization succeeded, continue with lzma_code().
* - LZMA_MEM_ERROR
* - LZMA_PROG_ERROR
*/
extern LZMA_API(lzma_ret) lzma_index_encoder(
lzma_stream *strm, const lzma_index *i)
lzma_nothrow lzma_attr_warn_unused_result;
/**
* \brief Initialize .xz Index decoder
*
* \param strm Pointer to properly prepared lzma_stream
* \param i The decoded Index will be made available via
* this pointer. Initially this function will
* set *i to NULL (the old value is ignored). If
* decoding succeeds (lzma_code() returns
* LZMA_STREAM_END), *i will be set to point
* to a new lzma_index, which the application
* has to later free with lzma_index_end().
* \param memlimit How much memory the resulting lzma_index is
* allowed to require. liblzma 5.2.3 and earlier
* don't allow 0 here and return LZMA_PROG_ERROR;
* later versions treat 0 as if 1 had been specified.
*
* Valid `action' arguments to lzma_code() are LZMA_RUN and LZMA_FINISH.
* There is no need to use LZMA_FINISH, but it's allowed because it may
* simplify certain types of applications.
*
* \return - LZMA_OK: Initialization succeeded, continue with lzma_code().
* - LZMA_MEM_ERROR
* - LZMA_PROG_ERROR
*
* liblzma 5.2.3 and older list also LZMA_MEMLIMIT_ERROR here
* but that error code has never been possible from this
* initialization function.
*/
extern LZMA_API(lzma_ret) lzma_index_decoder(
lzma_stream *strm, lzma_index **i, uint64_t memlimit)
lzma_nothrow lzma_attr_warn_unused_result;
/**
* \brief Single-call .xz Index encoder
*
* \param i lzma_index to be encoded
* \param out Beginning of the output buffer
* \param out_pos The next byte will be written to out[*out_pos].
* *out_pos is updated only if encoding succeeds.
* \param out_size Size of the out buffer; the first byte into
* which no data is written to is out[out_size].
*
* \return - LZMA_OK: Encoding was successful.
* - LZMA_BUF_ERROR: Output buffer is too small. Use
* lzma_index_size() to find out how much output
* space is needed.
* - LZMA_PROG_ERROR
*
* \note This function doesn't take allocator argument since all
* the internal data is allocated on stack.
*/
extern LZMA_API(lzma_ret) lzma_index_buffer_encode(const lzma_index *i,
uint8_t *out, size_t *out_pos, size_t out_size) lzma_nothrow;
/**
* \brief Single-call .xz Index decoder
*
* \param i If decoding succeeds, *i will point to a new
* lzma_index, which the application has to
* later free with lzma_index_end(). If an error
* occurs, *i will be NULL. The old value of *i
* is always ignored and thus doesn't need to be
* initialized by the caller.
* \param memlimit Pointer to how much memory the resulting
* lzma_index is allowed to require. The value
* pointed by this pointer is modified if and only
* if LZMA_MEMLIMIT_ERROR is returned.
* \param allocator Pointer to lzma_allocator, or NULL to use malloc()
* \param in Beginning of the input buffer
* \param in_pos The next byte will be read from in[*in_pos].
* *in_pos is updated only if decoding succeeds.
* \param in_size Size of the input buffer; the first byte that
* won't be read is in[in_size].
*
* \return - LZMA_OK: Decoding was successful.
* - LZMA_MEM_ERROR
* - LZMA_MEMLIMIT_ERROR: Memory usage limit was reached.
* The minimum required memlimit value was stored to *memlimit.
* - LZMA_DATA_ERROR
* - LZMA_PROG_ERROR
*/
extern LZMA_API(lzma_ret) lzma_index_buffer_decode(lzma_index **i,
uint64_t *memlimit, const lzma_allocator *allocator,
const uint8_t *in, size_t *in_pos, size_t in_size)
lzma_nothrow;