summaryrefslogtreecommitdiffstats
path: root/doc/lzlib.info
diff options
context:
space:
mode:
authorDaniel Baumann <daniel.baumann@progress-linux.org>2024-05-04 14:25:58 +0000
committerDaniel Baumann <daniel.baumann@progress-linux.org>2024-05-04 14:25:58 +0000
commitba33de40d6674e5d94bfae3d1a20648cd5ba4fba (patch)
tree56fad1ae369f72a13426af15677dcead81c1eb0b /doc/lzlib.info
parentInitial commit. (diff)
downloadlzlib-ba33de40d6674e5d94bfae3d1a20648cd5ba4fba.tar.xz
lzlib-ba33de40d6674e5d94bfae3d1a20648cd5ba4fba.zip
Adding upstream version 1.13.upstream/1.13upstream
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
Diffstat (limited to 'doc/lzlib.info')
-rw-r--r--doc/lzlib.info1323
1 files changed, 1323 insertions, 0 deletions
diff --git a/doc/lzlib.info b/doc/lzlib.info
new file mode 100644
index 0000000..d81bc88
--- /dev/null
+++ b/doc/lzlib.info
@@ -0,0 +1,1323 @@
+This is lzlib.info, produced by makeinfo version 4.13+ from lzlib.texi.
+
+INFO-DIR-SECTION Compression
+START-INFO-DIR-ENTRY
+* Lzlib: (lzlib). Compression library for the lzip format
+END-INFO-DIR-ENTRY
+
+
+File: lzlib.info, Node: Top, Next: Introduction, Up: (dir)
+
+Lzlib Manual
+************
+
+This manual is for Lzlib (version 1.13, 23 January 2022).
+
+* Menu:
+
+* Introduction:: Purpose and features of lzlib
+* Library version:: Checking library version
+* Buffering:: Sizes of lzlib's buffers
+* Parameter limits:: Min / max values for some parameters
+* Compression functions:: Descriptions of the compression functions
+* Decompression functions:: Descriptions of the decompression functions
+* Error codes:: Meaning of codes returned by functions
+* Error messages:: Error messages corresponding to error codes
+* Invoking minilzip:: Command line interface of the test program
+* Data format:: Detailed format of the compressed data
+* Examples:: A small tutorial with examples
+* Problems:: Reporting bugs
+* Concept index:: Index of concepts
+
+
+ Copyright (C) 2009-2022 Antonio Diaz Diaz.
+
+ This manual is free documentation: you have unlimited permission to copy,
+distribute, and modify it.
+
+
+File: lzlib.info, Node: Introduction, Next: Library version, Prev: Top, Up: Top
+
+1 Introduction
+**************
+
+Lzlib is a data compression library providing in-memory LZMA compression and
+decompression functions, including integrity checking of the decompressed
+data. The compressed data format used by the library is the lzip format.
+Lzlib is written in C.
+
+ The lzip file format is designed for data sharing and long-term
+archiving, taking into account both data integrity and decoder availability:
+
+ * The lzip format provides very safe integrity checking and some data
+ recovery means. The program lziprecover can repair bit flip errors
+ (one of the most common forms of data corruption) in lzip files, and
+ provides data recovery capabilities, including error-checked merging
+ of damaged copies of a file. *Note Data safety: (lziprecover)Data
+ safety.
+
+ * The lzip format is as simple as possible (but not simpler). The lzip
+ manual provides the source code of a simple decompressor along with a
+ detailed explanation of how it works, so that with the only help of the
+ lzip manual it would be possible for a digital archaeologist to extract
+ the data from a lzip file long after quantum computers eventually
+ render LZMA obsolete.
+
+ * Additionally the lzip reference implementation is copylefted, which
+ guarantees that it will remain free forever.
+
+ A nice feature of the lzip format is that a corrupt byte is easier to
+repair the nearer it is from the beginning of the file. Therefore, with the
+help of lziprecover, losing an entire archive just because of a corrupt
+byte near the beginning is a thing of the past.
+
+ The functions and variables forming the interface of the compression
+library are declared in the file 'lzlib.h'. Usage examples of the library
+are given in the files 'bbexample.c', 'ffexample.c', and 'minilzip.c' from
+the source distribution.
+
+ All the library functions are thread safe. The library does not install
+any signal handler. The decoder checks the consistency of the compressed
+data, so the library should never crash even in case of corrupted input.
+
+ Compression/decompression is done by repeatedly calling a couple of
+read/write functions until all the data have been processed by the library.
+This interface is safer and less error prone than the traditional zlib
+interface.
+
+ Compression/decompression is done when the read function is called. This
+means the value returned by the position functions will not be updated until
+a read call, even if a lot of data are written. If you want the data to be
+compressed in advance, just call the read function with a SIZE equal to 0.
+
+ If all the data to be compressed are written in advance, lzlib will
+automatically adjust the header of the compressed data to use the largest
+dictionary size that does not exceed neither the data size nor the limit
+given to 'LZ_compress_open'. This feature reduces the amount of memory
+needed for decompression and allows minilzip to produce identical compressed
+output as lzip.
+
+ Lzlib will correctly decompress a data stream which is the concatenation
+of two or more compressed data streams. The result is the concatenation of
+the corresponding decompressed data streams. Integrity testing of
+concatenated compressed data streams is also supported.
+
+ Lzlib is able to compress and decompress streams of unlimited size by
+automatically creating multimember output. The members so created are large,
+about 2 PiB each.
+
+ In spite of its name (Lempel-Ziv-Markov chain-Algorithm), LZMA is not a
+concrete algorithm; it is more like "any algorithm using the LZMA coding
+scheme". For example, the option '-0' of lzip uses the scheme in almost the
+simplest way possible; issuing the longest match it can find, or a literal
+byte if it can't find a match. Inversely, a much more elaborated way of
+finding coding sequences of minimum size than the one currently used by lzip
+could be developed, and the resulting sequence could also be coded using the
+LZMA coding scheme.
+
+ Lzlib currently implements two variants of the LZMA algorithm: fast
+(used by option '-0' of minilzip) and normal (used by all other compression
+levels).
+
+ The high compression of LZMA comes from combining two basic, well-proven
+compression ideas: sliding dictionaries (LZ77/78) and markov models (the
+thing used by every compression algorithm that uses a range encoder or
+similar order-0 entropy coder as its last stage) with segregation of
+contexts according to what the bits are used for.
+
+ The ideas embodied in lzlib are due to (at least) the following people:
+Abraham Lempel and Jacob Ziv (for the LZ algorithm), Andrey Markov (for the
+definition of Markov chains), G.N.N. Martin (for the definition of range
+encoding), Igor Pavlov (for putting all the above together in LZMA), and
+Julian Seward (for bzip2's CLI).
+
+ LANGUAGE NOTE: Uncompressed = not compressed = plain data; it may never
+have been compressed. Decompressed is used to refer to data which have
+undergone the process of decompression.
+
+
+File: lzlib.info, Node: Library version, Next: Buffering, Prev: Introduction, Up: Top
+
+2 Library version
+*****************
+
+One goal of lzlib is to keep perfect backward compatibility with older
+versions of itself down to 1.0. Any application working with an older lzlib
+should work with a newer lzlib. Installing a newer lzlib should not break
+anything. This chapter describes the constants and functions that the
+application can use to discover the version of the library being used. All
+of them are declared in 'lzlib.h'.
+
+ -- Constant: LZ_API_VERSION
+ This constant is defined in 'lzlib.h' and works as a version test
+ macro. The application should verify at compile time that
+ LZ_API_VERSION is greater than or equal to the version required by the
+ application:
+
+ #if !defined LZ_API_VERSION || LZ_API_VERSION < 1012
+ #error "lzlib 1.12 or newer needed."
+ #endif
+
+ Before version 1.8, lzlib didn't define LZ_API_VERSION.
+ LZ_API_VERSION was first defined in lzlib 1.8 to 1.
+ Since lzlib 1.12, LZ_API_VERSION is defined as (major * 1000 + minor).
+
+ NOTE: Version test macros are the library's way of announcing
+functionality to the application. They should not be confused with feature
+test macros, which allow the application to announce to the library its
+desire to have certain symbols and prototypes exposed.
+
+ -- Function: int LZ_api_version ( void )
+ If LZ_API_VERSION >= 1012, this function is declared in 'lzlib.h' (else
+ it doesn't exist). It returns the LZ_API_VERSION of the library object
+ code being used. The application should verify at run time that the
+ value returned by 'LZ_api_version' is greater than or equal to the
+ version required by the application. An application may be dinamically
+ linked at run time with a different version of lzlib than the one it
+ was compiled for, and this should not break the program as long as the
+ library used provides the functionality required by the application.
+
+ #if defined LZ_API_VERSION && LZ_API_VERSION >= 1012
+ if( LZ_api_version() < 1012 )
+ show_error( "lzlib 1.12 or newer needed." );
+ #endif
+
+ -- Constant: const char * LZ_version_string
+ This string constant is defined in the header file 'lzlib.h' and
+ represents the version of the library being used at compile time.
+
+ -- Function: const char * LZ_version ( void )
+ This function returns a string representing the version of the library
+ being used at run time.
+
+
+File: lzlib.info, Node: Buffering, Next: Parameter limits, Prev: Library version, Up: Top
+
+3 Buffering
+***********
+
+Lzlib internal functions need access to a memory chunk at least as large as
+the dictionary size (sliding window). For efficiency reasons, the input
+buffer for compression is twice or sixteen times as large as the dictionary
+size.
+
+ Finally, for safety reasons, lzlib uses two more internal buffers.
+
+ These are the four buffers used by lzlib, and their guaranteed minimum
+sizes:
+
+ * Input compression buffer. Written to by the function
+ 'LZ_compress_write'. For the normal variant of LZMA, its size is two
+ times the dictionary size set with the function 'LZ_compress_open' or
+ 64 KiB, whichever is larger. For the fast variant, its size is 1 MiB.
+
+ * Output compression buffer. Read from by the function
+ 'LZ_compress_read'. Its size is 64 KiB.
+
+ * Input decompression buffer. Written to by the function
+ 'LZ_decompress_write'. Its size is 64 KiB.
+
+ * Output decompression buffer. Read from by the function
+ 'LZ_decompress_read'. Its size is the dictionary size set in the header
+ of the member currently being decompressed or 64 KiB, whichever is
+ larger.
+
+
+File: lzlib.info, Node: Parameter limits, Next: Compression functions, Prev: Buffering, Up: Top
+
+4 Parameter limits
+******************
+
+These functions provide minimum and maximum values for some parameters.
+Current values are shown in square brackets.
+
+ -- Function: int LZ_min_dictionary_bits ( void )
+ Returns the base 2 logarithm of the smallest valid dictionary size
+ [12].
+
+ -- Function: int LZ_min_dictionary_size ( void )
+ Returns the smallest valid dictionary size [4 KiB].
+
+ -- Function: int LZ_max_dictionary_bits ( void )
+ Returns the base 2 logarithm of the largest valid dictionary size [29].
+
+ -- Function: int LZ_max_dictionary_size ( void )
+ Returns the largest valid dictionary size [512 MiB].
+
+ -- Function: int LZ_min_match_len_limit ( void )
+ Returns the smallest valid match length limit [5].
+
+ -- Function: int LZ_max_match_len_limit ( void )
+ Returns the largest valid match length limit [273].
+
+
+File: lzlib.info, Node: Compression functions, Next: Decompression functions, Prev: Parameter limits, Up: Top
+
+5 Compression functions
+***********************
+
+These are the functions used to compress data. In case of error, all of
+them return -1 or 0, for signed and unsigned return values respectively,
+except 'LZ_compress_open' whose return value must be verified by calling
+'LZ_compress_errno' before using it.
+
+ -- Function: struct LZ_Encoder * LZ_compress_open ( const int
+ DICTIONARY_SIZE, const int MATCH_LEN_LIMIT, const unsigned long
+ long MEMBER_SIZE )
+ Initializes the internal stream state for compression and returns a
+ pointer that can only be used as the ENCODER argument for the other
+ LZ_compress functions, or a null pointer if the encoder could not be
+ allocated.
+
+ The returned pointer must be verified by calling 'LZ_compress_errno'
+ before using it. If 'LZ_compress_errno' does not return 'LZ_ok', the
+ returned pointer must not be used and should be freed with
+ 'LZ_compress_close' to avoid memory leaks.
+
+ DICTIONARY_SIZE sets the dictionary size to be used, in bytes. Valid
+ values range from 4 KiB to 512 MiB. Note that dictionary sizes are
+ quantized. If the size specified does not match one of the valid
+ sizes, it will be rounded upwards by adding up to
+ (DICTIONARY_SIZE / 8) to it.
+
+ MATCH_LEN_LIMIT sets the match length limit in bytes. Valid values
+ range from 5 to 273. Larger values usually give better compression
+ ratios but longer compression times.
+
+ If DICTIONARY_SIZE is 65535 and MATCH_LEN_LIMIT is 16, the fast
+ variant of LZMA is chosen, which produces identical compressed output
+ as 'lzip -0'. (The dictionary size used will be rounded upwards to
+ 64 KiB).
+
+ MEMBER_SIZE sets the member size limit in bytes. Valid values range
+ from 4 KiB to 2 PiB. A small member size may degrade compression
+ ratio, so use it only when needed. To produce a single-member data
+ stream, give MEMBER_SIZE a value larger than the amount of data to be
+ produced. Values larger than 2 PiB will be reduced to 2 PiB to prevent
+ the uncompressed size of the member from overflowing.
+
+ -- Function: int LZ_compress_close ( struct LZ_Encoder * const ENCODER )
+ Frees all dynamically allocated data structures for this stream. This
+ function discards any unprocessed input and does not flush any pending
+ output. After a call to 'LZ_compress_close', ENCODER can no longer be
+ used as an argument to any LZ_compress function. It is safe to call
+ 'LZ_compress_close' with a null argument.
+
+ -- Function: int LZ_compress_finish ( struct LZ_Encoder * const ENCODER )
+ Use this function to tell 'lzlib' that all the data for this member
+ have already been written (with the function 'LZ_compress_write'). It
+ is safe to call 'LZ_compress_finish' as many times as needed. After
+ all the compressed data have been read with 'LZ_compress_read' and
+ 'LZ_compress_member_finished' returns 1, a new member can be started
+ with 'LZ_compress_restart_member'.
+
+ -- Function: int LZ_compress_restart_member ( struct LZ_Encoder * const
+ ENCODER, const unsigned long long MEMBER_SIZE )
+ Use this function to start a new member in a multimember data stream.
+ Call this function only after 'LZ_compress_member_finished' indicates
+ that the current member has been fully read (with the function
+ 'LZ_compress_read'). *Note member_size::, for a description of
+ MEMBER_SIZE.
+
+ -- Function: int LZ_compress_sync_flush ( struct LZ_Encoder * const
+ ENCODER )
+ Use this function to make available to 'LZ_compress_read' all the data
+ already written with the function 'LZ_compress_write'. First call
+ 'LZ_compress_sync_flush'. Then call 'LZ_compress_read' until it
+ returns 0.
+
+ This function writes at least one LZMA marker '3' ("Sync Flush" marker)
+ to the compressed output. Note that the sync flush marker is not
+ allowed in lzip files; it is a device for interactive communication
+ between applications using lzlib, but is useless and wasteful in a
+ file, and is excluded from the media type 'application/lzip'. The LZMA
+ marker '2' ("End Of Stream" marker) is the only marker allowed in lzip
+ files. *Note Data format::.
+
+ Repeated use of 'LZ_compress_sync_flush' may degrade compression
+ ratio, so use it only when needed. If the interval between calls to
+ 'LZ_compress_sync_flush' is large (comparable to dictionary size),
+ creating a multimember data stream with 'LZ_compress_restart_member'
+ may be an alternative.
+
+ Combining multimember stream creation with flushing may be tricky. If
+ there are more bytes available than those needed to complete
+ MEMBER_SIZE, 'LZ_compress_restart_member' needs to be called when
+ 'LZ_compress_member_finished' returns 1, followed by a new call to
+ 'LZ_compress_sync_flush'.
+
+ -- Function: int LZ_compress_read ( struct LZ_Encoder * const ENCODER,
+ uint8_t * const BUFFER, const int SIZE )
+ Reads up to SIZE bytes from the stream pointed to by ENCODER, storing
+ the results in BUFFER. If LZ_API_VERSION >= 1012, BUFFER may be a null
+ pointer, in which case the bytes read are discarded.
+
+ Returns the number of bytes actually read. This might be less than
+ SIZE; for example, if there aren't that many bytes left in the stream
+ or if more bytes have to be yet written with the function
+ 'LZ_compress_write'. Note that reading less than SIZE bytes is not an
+ error.
+
+ -- Function: int LZ_compress_write ( struct LZ_Encoder * const ENCODER,
+ uint8_t * const BUFFER, const int SIZE )
+ Writes up to SIZE bytes from BUFFER to the stream pointed to by
+ ENCODER. Returns the number of bytes actually written. This might be
+ less than SIZE. Note that writing less than SIZE bytes is not an error.
+
+ -- Function: int LZ_compress_write_size ( struct LZ_Encoder * const
+ ENCODER )
+ Returns the maximum number of bytes that can be immediately written
+ through 'LZ_compress_write'. For efficiency reasons, once the input
+ buffer is full and 'LZ_compress_write_size' returns 0, almost all the
+ buffer must be compressed before a size greater than 0 is returned
+ again. (This is done to minimize the amount of data that must be
+ copied to the beginning of the buffer before new data can be accepted).
+
+ It is guaranteed that an immediate call to 'LZ_compress_write' will
+ accept a SIZE up to the returned number of bytes.
+
+ -- Function: enum LZ_Errno LZ_compress_errno ( struct LZ_Encoder * const
+ ENCODER )
+ Returns the current error code for ENCODER. *Note Error codes::. It is
+ safe to call 'LZ_compress_errno' with a null argument, in which case
+ it returns 'LZ_bad_argument'.
+
+ -- Function: int LZ_compress_finished ( struct LZ_Encoder * const ENCODER )
+ Returns 1 if all the data have been read and 'LZ_compress_close' can
+ be safely called. Otherwise it returns 0. 'LZ_compress_finished'
+ implies 'LZ_compress_member_finished'.
+
+ -- Function: int LZ_compress_member_finished ( struct LZ_Encoder * const
+ ENCODER )
+ Returns 1 if the current member, in a multimember data stream, has been
+ fully read and 'LZ_compress_restart_member' can be safely called.
+ Otherwise it returns 0.
+
+ -- Function: unsigned long long LZ_compress_data_position ( struct
+ LZ_Encoder * const ENCODER )
+ Returns the number of input bytes already compressed in the current
+ member.
+
+ -- Function: unsigned long long LZ_compress_member_position ( struct
+ LZ_Encoder * const ENCODER )
+ Returns the number of compressed bytes already produced, but perhaps
+ not yet read, in the current member.
+
+ -- Function: unsigned long long LZ_compress_total_in_size ( struct
+ LZ_Encoder * const ENCODER )
+ Returns the total number of input bytes already compressed.
+
+ -- Function: unsigned long long LZ_compress_total_out_size ( struct
+ LZ_Encoder * const ENCODER )
+ Returns the total number of compressed bytes already produced, but
+ perhaps not yet read.
+
+
+File: lzlib.info, Node: Decompression functions, Next: Error codes, Prev: Compression functions, Up: Top
+
+6 Decompression functions
+*************************
+
+These are the functions used to decompress data. In case of error, all of
+them return -1 or 0, for signed and unsigned return values respectively,
+except 'LZ_decompress_open' whose return value must be verified by calling
+'LZ_decompress_errno' before using it.
+
+ -- Function: struct LZ_Decoder * LZ_decompress_open ( void )
+ Initializes the internal stream state for decompression and returns a
+ pointer that can only be used as the DECODER argument for the other
+ LZ_decompress functions, or a null pointer if the decoder could not be
+ allocated.
+
+ The returned pointer must be verified by calling 'LZ_decompress_errno'
+ before using it. If 'LZ_decompress_errno' does not return 'LZ_ok', the
+ returned pointer must not be used and should be freed with
+ 'LZ_decompress_close' to avoid memory leaks.
+
+ -- Function: int LZ_decompress_close ( struct LZ_Decoder * const DECODER )
+ Frees all dynamically allocated data structures for this stream. This
+ function discards any unprocessed input and does not flush any pending
+ output. After a call to 'LZ_decompress_close', DECODER can no longer
+ be used as an argument to any LZ_decompress function. It is safe to
+ call 'LZ_decompress_close' with a null argument.
+
+ -- Function: int LZ_decompress_finish ( struct LZ_Decoder * const DECODER )
+ Use this function to tell 'lzlib' that all the data for this stream
+ have already been written (with the function 'LZ_decompress_write').
+ It is safe to call 'LZ_decompress_finish' as many times as needed. It
+ is not required to call 'LZ_decompress_finish' if the input stream
+ only contains whole members, but not calling it prevents lzlib from
+ detecting a truncated member.
+
+ -- Function: int LZ_decompress_reset ( struct LZ_Decoder * const DECODER )
+ Resets the internal state of DECODER as it was just after opening it
+ with the function 'LZ_decompress_open'. Data stored in the internal
+ buffers is discarded. Position counters are set to 0.
+
+ -- Function: int LZ_decompress_sync_to_member ( struct LZ_Decoder * const
+ DECODER )
+ Resets the error state of DECODER and enters a search state that lasts
+ until a new member header (or the end of the stream) is found. After a
+ successful call to 'LZ_decompress_sync_to_member', data written with
+ 'LZ_decompress_write' will be consumed and 'LZ_decompress_read' will
+ return 0 until a header is found.
+
+ This function is useful to discard any data preceding the first member,
+ or to discard the rest of the current member, for example in case of a
+ data error. If the decoder is already at the beginning of a member,
+ this function does nothing.
+
+ -- Function: int LZ_decompress_read ( struct LZ_Decoder * const DECODER,
+ uint8_t * const BUFFER, const int SIZE )
+ Reads up to SIZE bytes from the stream pointed to by DECODER, storing
+ the results in BUFFER. If LZ_API_VERSION >= 1012, BUFFER may be a null
+ pointer, in which case the bytes read are discarded.
+
+ Returns the number of bytes actually read. This might be less than
+ SIZE; for example, if there aren't that many bytes left in the stream
+ or if more bytes have to be yet written with the function
+ 'LZ_decompress_write'. Note that reading less than SIZE bytes is not
+ an error.
+
+ 'LZ_decompress_read' returns at least once per member so that
+ 'LZ_decompress_member_finished' can be called (and trailer data
+ retrieved) for each member, even for empty members. Therefore,
+ 'LZ_decompress_read' returning 0 does not mean that the end of the
+ stream has been reached. The increase in the value returned by
+ 'LZ_decompress_total_in_size' can be used to tell the end of the stream
+ from an empty member.
+
+ In case of decompression error caused by corrupt or truncated data,
+ 'LZ_decompress_read' does not signal the error immediately to the
+ application, but waits until all the bytes decoded have been read. This
+ allows tools like tarlz to recover as much data as possible from each
+ damaged member. *Note tarlz manual: (tarlz)Top.
+
+ -- Function: int LZ_decompress_write ( struct LZ_Decoder * const DECODER,
+ uint8_t * const BUFFER, const int SIZE )
+ Writes up to SIZE bytes from BUFFER to the stream pointed to by
+ DECODER. Returns the number of bytes actually written. This might be
+ less than SIZE. Note that writing less than SIZE bytes is not an error.
+
+ -- Function: int LZ_decompress_write_size ( struct LZ_Decoder * const
+ DECODER )
+ Returns the maximum number of bytes that can be immediately written
+ through 'LZ_decompress_write'. This number varies smoothly; each
+ compressed byte consumed may be overwritten immediately, increasing by
+ 1 the value returned.
+
+ It is guaranteed that an immediate call to 'LZ_decompress_write' will
+ accept a SIZE up to the returned number of bytes.
+
+ -- Function: enum LZ_Errno LZ_decompress_errno ( struct LZ_Decoder * const
+ DECODER )
+ Returns the current error code for DECODER. *Note Error codes::. It is
+ safe to call 'LZ_decompress_errno' with a null argument, in which case
+ it returns 'LZ_bad_argument'.
+
+ -- Function: int LZ_decompress_finished ( struct LZ_Decoder * const
+ DECODER )
+ Returns 1 if all the data have been read and 'LZ_decompress_close' can
+ be safely called. Otherwise it returns 0. 'LZ_decompress_finished'
+ does not imply 'LZ_decompress_member_finished'.
+
+ -- Function: int LZ_decompress_member_finished ( struct LZ_Decoder * const
+ DECODER )
+ Returns 1 if the previous call to 'LZ_decompress_read' finished reading
+ the current member, indicating that final values for the member are
+ available through 'LZ_decompress_data_crc',
+ 'LZ_decompress_data_position', and 'LZ_decompress_member_position'.
+ Otherwise it returns 0.
+
+ -- Function: int LZ_decompress_member_version ( struct LZ_Decoder * const
+ DECODER )
+ Returns the version of the current member, read from the member header.
+
+ -- Function: int LZ_decompress_dictionary_size ( struct LZ_Decoder * const
+ DECODER )
+ Returns the dictionary size of the current member, read from the
+ member header.
+
+ -- Function: unsigned LZ_decompress_data_crc ( struct LZ_Decoder * const
+ DECODER )
+ Returns the 32 bit Cyclic Redundancy Check of the data decompressed
+ from the current member. The value returned is valid only when
+ 'LZ_decompress_member_finished' returns 1.
+
+ -- Function: unsigned long long LZ_decompress_data_position ( struct
+ LZ_Decoder * const DECODER )
+ Returns the number of decompressed bytes already produced, but perhaps
+ not yet read, in the current member.
+
+ -- Function: unsigned long long LZ_decompress_member_position ( struct
+ LZ_Decoder * const DECODER )
+ Returns the number of input bytes already decompressed in the current
+ member.
+
+ -- Function: unsigned long long LZ_decompress_total_in_size ( struct
+ LZ_Decoder * const DECODER )
+ Returns the total number of input bytes already decompressed.
+
+ -- Function: unsigned long long LZ_decompress_total_out_size ( struct
+ LZ_Decoder * const DECODER )
+ Returns the total number of decompressed bytes already produced, but
+ perhaps not yet read.
+
+
+File: lzlib.info, Node: Error codes, Next: Error messages, Prev: Decompression functions, Up: Top
+
+7 Error codes
+*************
+
+Most library functions return -1 to indicate that they have failed. But
+this return value only tells you that an error has occurred. To find out
+what kind of error it was, you need to verify the error code by calling
+'LZ_(de)compress_errno'.
+
+ Library functions don't change the value returned by
+'LZ_(de)compress_errno' when they succeed; thus, the value returned by
+'LZ_(de)compress_errno' after a successful call is not necessarily LZ_ok,
+and you should not use 'LZ_(de)compress_errno' to determine whether a call
+failed. If the call failed, then you can examine 'LZ_(de)compress_errno'.
+
+ The error codes are defined in the header file 'lzlib.h'.
+
+ -- Constant: enum LZ_Errno LZ_ok
+ The value of this constant is 0 and is used to indicate that there is
+ no error.
+
+ -- Constant: enum LZ_Errno LZ_bad_argument
+ At least one of the arguments passed to the library function was
+ invalid.
+
+ -- Constant: enum LZ_Errno LZ_mem_error
+ No memory available. The system cannot allocate more virtual memory
+ because its capacity is full.
+
+ -- Constant: enum LZ_Errno LZ_sequence_error
+ A library function was called in the wrong order. For example
+ 'LZ_compress_restart_member' was called before
+ 'LZ_compress_member_finished' indicates that the current member is
+ finished.
+
+ -- Constant: enum LZ_Errno LZ_header_error
+ An invalid member header (one with the wrong magic bytes) was read. If
+ this happens at the end of the data stream it may indicate trailing
+ data.
+
+ -- Constant: enum LZ_Errno LZ_unexpected_eof
+ The end of the data stream was reached in the middle of a member.
+
+ -- Constant: enum LZ_Errno LZ_data_error
+ The data stream is corrupt. If 'LZ_decompress_member_position' is 6 or
+ less, it indicates either a format version not supported, an invalid
+ dictionary size, a corrupt header in a multimember data stream, or
+ trailing data too similar to a valid lzip header. Lziprecover can be
+ used to remove conflicting trailing data from a file.
+
+ -- Constant: enum LZ_Errno LZ_library_error
+ A bug was detected in the library. Please, report it. *Note Problems::.
+
+
+File: lzlib.info, Node: Error messages, Next: Invoking minilzip, Prev: Error codes, Up: Top
+
+8 Error messages
+****************
+
+ -- Function: const char * LZ_strerror ( const enum LZ_Errno LZ_ERRNO )
+ Returns the standard error message for a given error code. The messages
+ are fairly short; there are no multi-line messages or embedded
+ newlines. This function makes it easy for your program to report
+ informative error messages about the failure of a library call.
+
+ The value of LZ_ERRNO normally comes from a call to
+ 'LZ_(de)compress_errno'.
+
+
+File: lzlib.info, Node: Invoking minilzip, Next: Data format, Prev: Error messages, Up: Top
+
+9 Invoking minilzip
+*******************
+
+Minilzip is a test program for the compression library lzlib, fully
+compatible with lzip 1.4 or newer.
+
+ Lzip is a lossless data compressor with a user interface similar to the
+one of gzip or bzip2. Lzip uses a simplified form of the 'Lempel-Ziv-Markov
+chain-Algorithm' (LZMA) stream format and provides a 3 factor integrity
+checking to maximize interoperability and optimize safety. Lzip can compress
+about as fast as gzip (lzip -0) or compress most files more than bzip2
+(lzip -9). Decompression speed is intermediate between gzip and bzip2. Lzip
+is better than gzip and bzip2 from a data recovery perspective. Lzip has
+been designed, written, and tested with great care to replace gzip and
+bzip2 as the standard general-purpose compressed format for unix-like
+systems.
+
+The format for running minilzip is:
+
+ minilzip [OPTIONS] [FILES]
+
+If no file names are specified, minilzip compresses (or decompresses) from
+standard input to standard output. A hyphen '-' used as a FILE argument
+means standard input. It can be mixed with other FILES and is read just
+once, the first time it appears in the command line.
+
+ minilzip supports the following options: *Note Argument syntax:
+(arg_parser)Argument syntax.
+
+'-h'
+'--help'
+ Print an informative help message describing the options and exit.
+
+'-V'
+'--version'
+ Print the version number of minilzip on the standard output and exit.
+ This version number should be included in all bug reports.
+
+'-a'
+'--trailing-error'
+ Exit with error status 2 if any remaining input is detected after
+ decompressing the last member. Such remaining input is usually trailing
+ garbage that can be safely ignored.
+
+'-b BYTES'
+'--member-size=BYTES'
+ When compressing, set the member size limit to BYTES. It is advisable
+ to keep members smaller than RAM size so that they can be repaired with
+ lziprecover in case of corruption. A small member size may degrade
+ compression ratio, so use it only when needed. Valid values range from
+ 100 kB to 2 PiB. Defaults to 2 PiB.
+
+'-c'
+'--stdout'
+ Compress or decompress to standard output; keep input files unchanged.
+ If compressing several files, each file is compressed independently.
+ (The output consists of a sequence of independently compressed
+ members). This option (or '-o') is needed when reading from a named
+ pipe (fifo) or from a device. Use it also to recover as much of the
+ decompressed data as possible when decompressing a corrupt file. '-c'
+ overrides '-o' and '-S'. '-c' has no effect when testing or listing.
+
+'-d'
+'--decompress'
+ Decompress the files specified. If a file does not exist, can't be
+ opened, or the destination file already exists and '--force' has not
+ been specified, minilzip continues decompressing the rest of the files
+ and exits with error status 1. If a file fails to decompress, or is a
+ terminal, minilzip exits immediately with error status 2 without
+ decompressing the rest of the files. A terminal is considered an
+ uncompressed file, and therefore invalid.
+
+'-f'
+'--force'
+ Force overwrite of output files.
+
+'-F'
+'--recompress'
+ When compressing, force re-compression of files whose name already has
+ the '.lz' or '.tlz' suffix.
+
+'-k'
+'--keep'
+ Keep (don't delete) input files during compression or decompression.
+
+'-m BYTES'
+'--match-length=BYTES'
+ When compressing, set the match length limit in bytes. After a match
+ this long is found, the search is finished. Valid values range from 5
+ to 273. Larger values usually give better compression ratios but longer
+ compression times.
+
+'-o FILE'
+'--output=FILE'
+ If '-c' has not been also specified, write the (de)compressed output to
+ FILE; keep input files unchanged. If compressing several files, each
+ file is compressed independently. (The output consists of a sequence of
+ independently compressed members). This option (or '-c') is needed when
+ reading from a named pipe (fifo) or from a device. '-o -' is
+ equivalent to '-c'. '-o' has no effect when testing or listing.
+
+ When compressing and splitting the output in volumes, FILE is used as
+ a prefix, and several files named 'FILE00001.lz', 'FILE00002.lz', etc,
+ are created. In this case, only one input file is allowed.
+
+'-q'
+'--quiet'
+ Quiet operation. Suppress all messages.
+
+'-s BYTES'
+'--dictionary-size=BYTES'
+ When compressing, set the dictionary size limit in bytes. Minilzip
+ will use for each file the largest dictionary size that does not
+ exceed neither the file size nor this limit. Valid values range from
+ 4 KiB to 512 MiB. Values 12 to 29 are interpreted as powers of two,
+ meaning 2^12 to 2^29 bytes. Dictionary sizes are quantized so that
+ they can be coded in just one byte (*note coded-dict-size::). If the
+ size specified does not match one of the valid sizes, it will be
+ rounded upwards by adding up to (BYTES / 8) to it.
+
+ For maximum compression you should use a dictionary size limit as large
+ as possible, but keep in mind that the decompression memory requirement
+ is affected at compression time by the choice of dictionary size limit.
+
+'-S BYTES'
+'--volume-size=BYTES'
+ When compressing, and '-c' has not been also specified, split the
+ compressed output into several volume files with names
+ 'original_name00001.lz', 'original_name00002.lz', etc, and set the
+ volume size limit to BYTES. Input files are kept unchanged. Each
+ volume is a complete, maybe multimember, lzip file. A small volume
+ size may degrade compression ratio, so use it only when needed. Valid
+ values range from 100 kB to 4 EiB.
+
+'-t'
+'--test'
+ Check integrity of the files specified, but don't decompress them. This
+ really performs a trial decompression and throws away the result. Use
+ it together with '-v' to see information about the files. If a file
+ fails the test, does not exist, can't be opened, or is a terminal,
+ minilzip continues checking the rest of the files. A final diagnostic
+ is shown at verbosity level 1 or higher if any file fails the test
+ when testing multiple files.
+
+'-v'
+'--verbose'
+ Verbose mode.
+ When compressing, show the compression ratio and size for each file
+ processed.
+ When decompressing or testing, further -v's (up to 4) increase the
+ verbosity level, showing status, compression ratio, dictionary size,
+ and trailer contents (CRC, data size, member size).
+
+'-0 .. -9'
+ Compression level. Set the compression parameters (dictionary size and
+ match length limit) as shown in the table below. The default
+ compression level is '-6', equivalent to '-s8MiB -m36'. Note that '-9'
+ can be much slower than '-0'. These options have no effect when
+ decompressing or testing.
+
+ The bidimensional parameter space of LZMA can't be mapped to a linear
+ scale optimal for all files. If your files are large, very repetitive,
+ etc, you may need to use the options '--dictionary-size' and
+ '--match-length' directly to achieve optimal performance.
+
+ If several compression levels or '-s' or '-m' options are given, the
+ last setting is used. For example '-9 -s64MiB' is equivalent to
+ '-s64MiB -m273'
+
+ Level Dictionary size (-s) Match length limit (-m)
+ -0 64 KiB 16 bytes
+ -1 1 MiB 5 bytes
+ -2 1.5 MiB 6 bytes
+ -3 2 MiB 8 bytes
+ -4 3 MiB 12 bytes
+ -5 4 MiB 20 bytes
+ -6 8 MiB 36 bytes
+ -7 16 MiB 68 bytes
+ -8 24 MiB 132 bytes
+ -9 32 MiB 273 bytes
+
+'--fast'
+'--best'
+ Aliases for GNU gzip compatibility.
+
+'--loose-trailing'
+ When decompressing or testing, allow trailing data whose first bytes
+ are so similar to the magic bytes of a lzip header that they can be
+ confused with a corrupt header. Use this option if a file triggers a
+ "corrupt header" error and the cause is not indeed a corrupt header.
+
+'--check-lib'
+ Compare the version of lzlib used to compile minilzip with the version
+ actually being used at run time and exit. Report any differences
+ found. Exit with error status 1 if differences are found. A mismatch
+ may indicate that lzlib is not correctly installed or that a different
+ version of lzlib has been installed after compiling the shared version
+ of minilzip. Exit with error status 2 if LZ_API_VERSION and
+ LZ_version_string don't match. 'minilzip -v --check-lib' shows the
+ version of lzlib being used and the value of LZ_API_VERSION (if
+ defined). *Note Library version::.
+
+
+ Numbers given as arguments to options may be followed by a multiplier
+and an optional 'B' for "byte".
+
+ Table of SI and binary prefixes (unit multipliers):
+
+Prefix Value | Prefix Value
+k kilobyte (10^3 = 1000) | Ki kibibyte (2^10 = 1024)
+M megabyte (10^6) | Mi mebibyte (2^20)
+G gigabyte (10^9) | Gi gibibyte (2^30)
+T terabyte (10^12) | Ti tebibyte (2^40)
+P petabyte (10^15) | Pi pebibyte (2^50)
+E exabyte (10^18) | Ei exbibyte (2^60)
+Z zettabyte (10^21) | Zi zebibyte (2^70)
+Y yottabyte (10^24) | Yi yobibyte (2^80)
+
+
+ Exit status: 0 for a normal exit, 1 for environmental problems (file not
+found, invalid flags, I/O errors, etc), 2 to indicate a corrupt or invalid
+input file, 3 for an internal consistency error (e.g., bug) which caused
+minilzip to panic.
+
+
+File: lzlib.info, Node: Data format, Next: Examples, Prev: Invoking minilzip, Up: Top
+
+10 Data format
+**************
+
+Perfection is reached, not when there is no longer anything to add, but
+when there is no longer anything to take away.
+-- Antoine de Saint-Exupery
+
+
+ In the diagram below, a box like this:
+
++---+
+| | <-- the vertical bars might be missing
++---+
+
+ represents one byte; a box like this:
+
++==============+
+| |
++==============+
+
+ represents a variable number of bytes.
+
+
+ Lzip data consist of a series of independent "members" (compressed data
+sets). The members simply appear one after another in the data stream, with
+no additional information before, between, or after them. Each member can
+encode in compressed form up to 16 EiB - 1 byte of uncompressed data. The
+size of a multimember data stream is unlimited.
+
+ Each member has the following structure:
+
++--+--+--+--+----+----+=============+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
+| ID string | VN | DS | LZMA stream | CRC32 | Data size | Member size |
++--+--+--+--+----+----+=============+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
+
+ All multibyte values are stored in little endian order.
+
+'ID string (the "magic" bytes)'
+ A four byte string, identifying the lzip format, with the value "LZIP"
+ (0x4C, 0x5A, 0x49, 0x50).
+
+'VN (version number, 1 byte)'
+ Just in case something needs to be modified in the future. 1 for now.
+
+'DS (coded dictionary size, 1 byte)'
+ The dictionary size is calculated by taking a power of 2 (the base
+ size) and subtracting from it a fraction between 0/16 and 7/16 of the
+ base size.
+ Bits 4-0 contain the base 2 logarithm of the base size (12 to 29).
+ Bits 7-5 contain the numerator of the fraction (0 to 7) to subtract
+ from the base size to obtain the dictionary size.
+ Example: 0xD3 = 2^19 - 6 * 2^15 = 512 KiB - 6 * 32 KiB = 320 KiB
+ Valid values for dictionary size range from 4 KiB to 512 MiB.
+
+'LZMA stream'
+ The LZMA stream, finished by an "End Of Stream" marker. Uses default
+ values for encoder properties. *Note Stream format: (lzip)Stream
+ format, for a complete description.
+ Lzip only uses the LZMA marker '2' ("End Of Stream" marker). Lzlib
+ also uses the LZMA marker '3' ("Sync Flush" marker). *Note
+ sync_flush::.
+
+'CRC32 (4 bytes)'
+ Cyclic Redundancy Check (CRC) of the original uncompressed data.
+
+'Data size (8 bytes)'
+ Size of the original uncompressed data.
+
+'Member size (8 bytes)'
+ Total size of the member, including header and trailer. This field acts
+ as a distributed index, allows the verification of stream integrity,
+ and facilitates the safe recovery of undamaged members from
+ multimember files. Member size should be limited to 2 PiB to prevent
+ the data size field from overflowing.
+
+
+
+File: lzlib.info, Node: Examples, Next: Problems, Prev: Data format, Up: Top
+
+11 A small tutorial with examples
+*********************************
+
+This chapter provides real code examples for the most common uses of the
+library. See these examples in context in the files 'bbexample.c' and
+'ffexample.c' from the source distribution of lzlib.
+
+ Note that the interface of lzlib is symmetrical. That is, the code for
+normal compression and decompression is identical except because one calls
+LZ_compress* functions while the other calls LZ_decompress* functions.
+
+* Menu:
+
+* Buffer compression:: Buffer-to-buffer single-member compression
+* Buffer decompression:: Buffer-to-buffer decompression
+* File compression:: File-to-file single-member compression
+* File decompression:: File-to-file decompression
+* File compression mm:: File-to-file multimember compression
+* Skipping data errors:: Decompression with automatic resynchronization
+
+
+File: lzlib.info, Node: Buffer compression, Next: Buffer decompression, Up: Examples
+
+11.1 Buffer compression
+=======================
+
+Buffer-to-buffer single-member compression (MEMBER_SIZE > total output).
+
+/* Compress 'insize' bytes from 'inbuf' to 'outbuf'.
+ Return the size of the compressed data in '*outlenp'.
+ In case of error, or if 'outsize' is too small, return false and do not
+ modify '*outlenp'.
+*/
+bool bbcompress( const uint8_t * const inbuf, const int insize,
+ const int dictionary_size, const int match_len_limit,
+ uint8_t * const outbuf, const int outsize,
+ int * const outlenp )
+ {
+ int inpos = 0, outpos = 0;
+ bool error = false;
+ struct LZ_Encoder * const encoder =
+ LZ_compress_open( dictionary_size, match_len_limit, INT64_MAX );
+ if( !encoder || LZ_compress_errno( encoder ) != LZ_ok )
+ { LZ_compress_close( encoder ); return false; }
+
+ while( true )
+ {
+ int ret = LZ_compress_write( encoder, inbuf + inpos, insize - inpos );
+ if( ret < 0 ) { error = true; break; }
+ inpos += ret;
+ if( inpos >= insize ) LZ_compress_finish( encoder );
+ ret = LZ_compress_read( encoder, outbuf + outpos, outsize - outpos );
+ if( ret < 0 ) { error = true; break; }
+ outpos += ret;
+ if( LZ_compress_finished( encoder ) == 1 ) break;
+ if( outpos >= outsize ) { error = true; break; }
+ }
+
+ if( LZ_compress_close( encoder ) < 0 ) error = true;
+ if( error ) return false;
+ *outlenp = outpos;
+ return true;
+ }
+
+
+File: lzlib.info, Node: Buffer decompression, Next: File compression, Prev: Buffer compression, Up: Examples
+
+11.2 Buffer decompression
+=========================
+
+Buffer-to-buffer decompression.
+
+/* Decompress 'insize' bytes from 'inbuf' to 'outbuf'.
+ Return the size of the decompressed data in '*outlenp'.
+ In case of error, or if 'outsize' is too small, return false and do not
+ modify '*outlenp'.
+*/
+bool bbdecompress( const uint8_t * const inbuf, const int insize,
+ uint8_t * const outbuf, const int outsize,
+ int * const outlenp )
+ {
+ int inpos = 0, outpos = 0;
+ bool error = false;
+ struct LZ_Decoder * const decoder = LZ_decompress_open();
+ if( !decoder || LZ_decompress_errno( decoder ) != LZ_ok )
+ { LZ_decompress_close( decoder ); return false; }
+
+ while( true )
+ {
+ int ret = LZ_decompress_write( decoder, inbuf + inpos, insize - inpos );
+ if( ret < 0 ) { error = true; break; }
+ inpos += ret;
+ if( inpos >= insize ) LZ_decompress_finish( decoder );
+ ret = LZ_decompress_read( decoder, outbuf + outpos, outsize - outpos );
+ if( ret < 0 ) { error = true; break; }
+ outpos += ret;
+ if( LZ_decompress_finished( decoder ) == 1 ) break;
+ if( outpos >= outsize ) { error = true; break; }
+ }
+
+ if( LZ_decompress_close( decoder ) < 0 ) error = true;
+ if( error ) return false;
+ *outlenp = outpos;
+ return true;
+ }
+
+
+File: lzlib.info, Node: File compression, Next: File decompression, Prev: Buffer decompression, Up: Examples
+
+11.3 File compression
+=====================
+
+File-to-file compression using LZ_compress_write_size.
+
+int ffcompress( struct LZ_Encoder * const encoder,
+ FILE * const infile, FILE * const outfile )
+ {
+ enum { buffer_size = 16384 };
+ uint8_t buffer[buffer_size];
+ while( true )
+ {
+ int len, ret;
+ int size = min( buffer_size, LZ_compress_write_size( encoder ) );
+ if( size > 0 )
+ {
+ len = fread( buffer, 1, size, infile );
+ ret = LZ_compress_write( encoder, buffer, len );
+ if( ret < 0 || ferror( infile ) ) break;
+ if( feof( infile ) ) LZ_compress_finish( encoder );
+ }
+ ret = LZ_compress_read( encoder, buffer, buffer_size );
+ if( ret < 0 ) break;
+ len = fwrite( buffer, 1, ret, outfile );
+ if( len < ret ) break;
+ if( LZ_compress_finished( encoder ) == 1 ) return 0;
+ }
+ return 1;
+ }
+
+
+File: lzlib.info, Node: File decompression, Next: File compression mm, Prev: File compression, Up: Examples
+
+11.4 File decompression
+=======================
+
+File-to-file decompression using LZ_decompress_write_size.
+
+int ffdecompress( struct LZ_Decoder * const decoder,
+ FILE * const infile, FILE * const outfile )
+ {
+ enum { buffer_size = 16384 };
+ uint8_t buffer[buffer_size];
+ while( true )
+ {
+ int len, ret;
+ int size = min( buffer_size, LZ_decompress_write_size( decoder ) );
+ if( size > 0 )
+ {
+ len = fread( buffer, 1, size, infile );
+ ret = LZ_decompress_write( decoder, buffer, len );
+ if( ret < 0 || ferror( infile ) ) break;
+ if( feof( infile ) ) LZ_decompress_finish( decoder );
+ }
+ ret = LZ_decompress_read( decoder, buffer, buffer_size );
+ if( ret < 0 ) break;
+ len = fwrite( buffer, 1, ret, outfile );
+ if( len < ret ) break;
+ if( LZ_decompress_finished( decoder ) == 1 ) return 0;
+ }
+ return 1;
+ }
+
+
+File: lzlib.info, Node: File compression mm, Next: Skipping data errors, Prev: File decompression, Up: Examples
+
+11.5 File-to-file multimember compression
+=========================================
+
+Example 1: Multimember compression with members of fixed size
+(MEMBER_SIZE < total output).
+
+int ffmmcompress( FILE * const infile, FILE * const outfile )
+ {
+ enum { buffer_size = 16384, member_size = 4096 };
+ uint8_t buffer[buffer_size];
+ bool done = false;
+ struct LZ_Encoder * const encoder =
+ LZ_compress_open( 65535, 16, member_size );
+ if( !encoder || LZ_compress_errno( encoder ) != LZ_ok )
+ { fputs( "ffexample: Not enough memory.\n", stderr );
+ LZ_compress_close( encoder ); return 1; }
+ while( true )
+ {
+ int len, ret;
+ int size = min( buffer_size, LZ_compress_write_size( encoder ) );
+ if( size > 0 )
+ {
+ len = fread( buffer, 1, size, infile );
+ ret = LZ_compress_write( encoder, buffer, len );
+ if( ret < 0 || ferror( infile ) ) break;
+ if( feof( infile ) ) LZ_compress_finish( encoder );
+ }
+ ret = LZ_compress_read( encoder, buffer, buffer_size );
+ if( ret < 0 ) break;
+ len = fwrite( buffer, 1, ret, outfile );
+ if( len < ret ) break;
+ if( LZ_compress_member_finished( encoder ) == 1 )
+ {
+ if( LZ_compress_finished( encoder ) == 1 ) { done = true; break; }
+ if( LZ_compress_restart_member( encoder, member_size ) < 0 ) break;
+ }
+ }
+ if( LZ_compress_close( encoder ) < 0 ) done = false;
+ return done;
+ }
+
+
+Example 2: Multimember compression (user-restarted members). (Call
+LZ_compress_open with MEMBER_SIZE > largest member).
+
+/* Compress 'infile' to 'outfile' as a multimember stream with one member
+ for each line of text terminated by a newline character or by EOF.
+ Return 0 if success, 1 if error.
+*/
+int fflfcompress( struct LZ_Encoder * const encoder,
+ FILE * const infile, FILE * const outfile )
+ {
+ enum { buffer_size = 16384 };
+ uint8_t buffer[buffer_size];
+ while( true )
+ {
+ int len, ret;
+ int size = min( buffer_size, LZ_compress_write_size( encoder ) );
+ if( size > 0 )
+ {
+ for( len = 0; len < size; )
+ {
+ int ch = getc( infile );
+ if( ch == EOF || ( buffer[len++] = ch ) == '\n' ) break;
+ }
+ /* avoid writing an empty member to outfile */
+ if( len == 0 && LZ_compress_data_position( encoder ) == 0 ) return 0;
+ ret = LZ_compress_write( encoder, buffer, len );
+ if( ret < 0 || ferror( infile ) ) break;
+ if( feof( infile ) || buffer[len-1] == '\n' )
+ LZ_compress_finish( encoder );
+ }
+ ret = LZ_compress_read( encoder, buffer, buffer_size );
+ if( ret < 0 ) break;
+ len = fwrite( buffer, 1, ret, outfile );
+ if( len < ret ) break;
+ if( LZ_compress_member_finished( encoder ) == 1 )
+ {
+ if( feof( infile ) && LZ_compress_finished( encoder ) == 1 ) return 0;
+ if( LZ_compress_restart_member( encoder, INT64_MAX ) < 0 ) break;
+ }
+ }
+ return 1;
+ }
+
+
+File: lzlib.info, Node: Skipping data errors, Prev: File compression mm, Up: Examples
+
+11.6 Skipping data errors
+=========================
+
+/* Decompress 'infile' to 'outfile' with automatic resynchronization to
+ next member in case of data error, including the automatic removal of
+ leading garbage.
+*/
+int ffrsdecompress( struct LZ_Decoder * const decoder,
+ FILE * const infile, FILE * const outfile )
+ {
+ enum { buffer_size = 16384 };
+ uint8_t buffer[buffer_size];
+ while( true )
+ {
+ int len, ret;
+ int size = min( buffer_size, LZ_decompress_write_size( decoder ) );
+ if( size > 0 )
+ {
+ len = fread( buffer, 1, size, infile );
+ ret = LZ_decompress_write( decoder, buffer, len );
+ if( ret < 0 || ferror( infile ) ) break;
+ if( feof( infile ) ) LZ_decompress_finish( decoder );
+ }
+ ret = LZ_decompress_read( decoder, buffer, buffer_size );
+ if( ret < 0 )
+ {
+ if( LZ_decompress_errno( decoder ) == LZ_header_error ||
+ LZ_decompress_errno( decoder ) == LZ_data_error )
+ { LZ_decompress_sync_to_member( decoder ); continue; }
+ else break;
+ }
+ len = fwrite( buffer, 1, ret, outfile );
+ if( len < ret ) break;
+ if( LZ_decompress_finished( decoder ) == 1 ) return 0;
+ }
+ return 1;
+ }
+
+
+File: lzlib.info, Node: Problems, Next: Concept index, Prev: Examples, Up: Top
+
+12 Reporting bugs
+*****************
+
+There are probably bugs in lzlib. There are certainly errors and omissions
+in this manual. If you report them, they will get fixed. If you don't, no
+one will ever know about them and they will remain unfixed for all
+eternity, if not longer.
+
+ If you find a bug in lzlib, please send electronic mail to
+<lzip-bug@nongnu.org>. Include the version number, which you can find by
+running 'minilzip --version' and 'minilzip -v --check-lib'.
+
+
+File: lzlib.info, Node: Concept index, Prev: Problems, Up: Top
+
+Concept index
+*************
+
+
+* Menu:
+
+* buffer compression: Buffer compression. (line 6)
+* buffer decompression: Buffer decompression. (line 6)
+* buffering: Buffering. (line 6)
+* bugs: Problems. (line 6)
+* compression functions: Compression functions. (line 6)
+* data format: Data format. (line 6)
+* decompression functions: Decompression functions. (line 6)
+* error codes: Error codes. (line 6)
+* error messages: Error messages. (line 6)
+* examples: Examples. (line 6)
+* file compression: File compression. (line 6)
+* file decompression: File decompression. (line 6)
+* getting help: Problems. (line 6)
+* introduction: Introduction. (line 6)
+* invoking: Invoking minilzip. (line 6)
+* library version: Library version. (line 6)
+* multimember compression: File compression mm. (line 6)
+* options: Invoking minilzip. (line 6)
+* parameter limits: Parameter limits. (line 6)
+* skipping data errors: Skipping data errors. (line 6)
+
+
+
+Tag Table:
+Node: Top215
+Node: Introduction1338
+Node: Library version6413
+Node: Buffering8957
+Node: Parameter limits10182
+Node: Compression functions11136
+Ref: member_size12946
+Ref: sync_flush14712
+Node: Decompression functions19400
+Node: Error codes26968
+Node: Error messages29259
+Node: Invoking minilzip29838
+Node: Data format39786
+Ref: coded-dict-size41232
+Node: Examples42641
+Node: Buffer compression43602
+Node: Buffer decompression45122
+Node: File compression46536
+Node: File decompression47519
+Node: File compression mm48523
+Node: Skipping data errors51552
+Node: Problems52862
+Node: Concept index53423
+
+End Tag Table
+
+
+Local Variables:
+coding: iso-8859-15
+End: