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uint64_t | lzma_index_memusage (lzma_vli streams, lzma_vli blocks) lzma_nothrow |
| Calculate memory usage of lzma_index.
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uint64_t | lzma_index_memused (const lzma_index *i) lzma_nothrow |
| Calculate the memory usage of an existing lzma_index.
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lzma_index * | lzma_index_init (const lzma_allocator *allocator) lzma_nothrow |
| Allocate and initialize a new lzma_index structure.
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void | lzma_index_end (lzma_index *i, const lzma_allocator *allocator) lzma_nothrow |
| Deallocate lzma_index.
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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 |
| Add a new Block to lzma_index.
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lzma_ret | lzma_index_stream_flags (lzma_index *i, const lzma_stream_flags *stream_flags) lzma_nothrow lzma_attr_warn_unused_result |
| Set the Stream Flags.
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uint32_t | lzma_index_checks (const lzma_index *i) lzma_nothrow lzma_attr_pure |
| Get the types of integrity Checks.
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lzma_ret | lzma_index_stream_padding (lzma_index *i, lzma_vli stream_padding) lzma_nothrow lzma_attr_warn_unused_result |
| Set the amount of Stream Padding.
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lzma_vli | lzma_index_stream_count (const lzma_index *i) lzma_nothrow lzma_attr_pure |
| Get the number of Streams.
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lzma_vli | lzma_index_block_count (const lzma_index *i) lzma_nothrow lzma_attr_pure |
| Get the number of Blocks.
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lzma_vli | lzma_index_size (const lzma_index *i) lzma_nothrow lzma_attr_pure |
| Get the size of the Index field as bytes.
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lzma_vli | lzma_index_stream_size (const lzma_index *i) lzma_nothrow lzma_attr_pure |
| Get the total size of the Stream.
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lzma_vli | lzma_index_total_size (const lzma_index *i) lzma_nothrow lzma_attr_pure |
| Get the total size of the Blocks.
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lzma_vli | lzma_index_file_size (const lzma_index *i) lzma_nothrow lzma_attr_pure |
| Get the total size of the file.
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lzma_vli | lzma_index_uncompressed_size (const lzma_index *i) lzma_nothrow lzma_attr_pure |
| Get the uncompressed size of the file.
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void | lzma_index_iter_init (lzma_index_iter *iter, const lzma_index *i) lzma_nothrow |
| Initialize an iterator.
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void | lzma_index_iter_rewind (lzma_index_iter *iter) lzma_nothrow |
| Rewind the iterator.
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lzma_bool | lzma_index_iter_next (lzma_index_iter *iter, lzma_index_iter_mode mode) lzma_nothrow lzma_attr_warn_unused_result |
| Get the next Block or Stream.
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lzma_bool | lzma_index_iter_locate (lzma_index_iter *iter, lzma_vli target) lzma_nothrow |
| Locate a Block.
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lzma_ret | lzma_index_cat (lzma_index *dest, lzma_index *src, const lzma_allocator *allocator) lzma_nothrow lzma_attr_warn_unused_result |
| Concatenate lzma_indexes.
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lzma_index * | lzma_index_dup (const lzma_index *i, const lzma_allocator *allocator) lzma_nothrow lzma_attr_warn_unused_result |
| Duplicate lzma_index.
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lzma_ret | lzma_index_encoder (lzma_stream *strm, const lzma_index *i) lzma_nothrow lzma_attr_warn_unused_result |
| Initialize .xz Index encoder.
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lzma_ret | lzma_index_decoder (lzma_stream *strm, lzma_index **i, uint64_t memlimit) lzma_nothrow lzma_attr_warn_unused_result |
| Initialize .xz Index decoder.
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lzma_ret | lzma_index_buffer_encode (const lzma_index *i, uint8_t *out, size_t *out_pos, size_t out_size) lzma_nothrow |
| Single-call .xz Index encoder.
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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 |
| Single-call .xz Index decoder.
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lzma_ret | lzma_file_info_decoder (lzma_stream *strm, lzma_index **dest_index, uint64_t memlimit, uint64_t file_size) lzma_nothrow |
| Initialize a .xz file information decoder.
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Handling of .xz Index and related information.
- Note
- Never include this file directly. Use <lzma.h> instead.
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.
Calculate memory usage of lzma_index.
On disk, the size of the Index field depends on both the number of Records stored and the size of the Records (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 to 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.
- Parameters
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streams | Number of Streams |
blocks | Number of Blocks |
- Returns
- Approximate memory in bytes needed in a lzma_index structure.
Initialize an iterator.
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.
- Parameters
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iter | Pointer to a lzma_index_iter structure |
i | lzma_index to which the iterator will be associated |
Initialize a .xz file information decoder.
This decoder decodes the Stream Header, Stream Footer, Index, and Stream Padding field(s) from the input .xz file and stores the resulting combined index in *dest_index. This information can be used to get the uncompressed file size with lzma_index_uncompressed_size(*dest_index) or, for example, to implement random access reading by locating the Blocks in the Streams.
To get the required information from the .xz file, lzma_code() may ask the application to seek in the input file by returning LZMA_SEEK_NEEDED and having the target file position specified in lzma_stream.seek_pos. The number of seeks required depends on the input file and how big buffers the application provides. When possible, the decoder will seek backward and forward in the given buffer to avoid useless seek requests. Thus, if the application provides the whole file at once, no external seeking will be required (that is, lzma_code() won't return LZMA_SEEK_NEEDED).
The value in lzma_stream.total_in can be used to estimate how much data liblzma had to read to get the file information. However, due to seeking and the way total_in is updated, the value of total_in will be somewhat inaccurate (a little too big). Thus, total_in is a good estimate but don't expect to see the same exact value for the same file if you change the input buffer size or switch to a different liblzma version.
Valid `action' arguments to lzma_code() are LZMA_RUN and LZMA_FINISH. You only need to use LZMA_RUN; LZMA_FINISH is only supported because it might be convenient for some applications. If you use LZMA_FINISH and if lzma_code() asks the application to seek, remember to reset `action' back to LZMA_RUN unless you hit the end of the file again.
Possible return values from lzma_code():
- LZMA_OK: All OK so far, more input needed
- LZMA_SEEK_NEEDED: Provide more input starting from the absolute file position strm->seek_pos
- LZMA_STREAM_END: Decoding was successful, *dest_index has been set
- LZMA_FORMAT_ERROR: The input file is not in the .xz format (the expected magic bytes were not found from the beginning of the file)
- LZMA_OPTIONS_ERROR: File looks valid but contains headers that aren't supported by this version of liblzma
- LZMA_DATA_ERROR: File is corrupt
- LZMA_BUF_ERROR
- LZMA_MEM_ERROR
- LZMA_MEMLIMIT_ERROR
- LZMA_PROG_ERROR
- Parameters
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| strm | Pointer to a properly prepared lzma_stream |
[out] | dest_index | Pointer to a pointer where the decoder will put the decoded lzma_index. The old value of *dest_index is ignored (not freed). |
| memlimit | How much memory the resulting lzma_index is allowed to require. Use UINT64_MAX to effectively disable the limiter. |
| file_size | Size of the input .xz file |
- Returns
- Possible lzma_ret values:
- LZMA_OK
- LZMA_MEM_ERROR
- LZMA_PROG_ERROR