diff options
Diffstat (limited to 'doc/lzlib.texinfo')
| -rw-r--r-- | doc/lzlib.texinfo | 64 |
1 files changed, 35 insertions, 29 deletions
diff --git a/doc/lzlib.texinfo b/doc/lzlib.texinfo index 17b78f1..eeae174 100644 --- a/doc/lzlib.texinfo +++ b/doc/lzlib.texinfo @@ -6,8 +6,8 @@ @finalout @c %**end of header -@set UPDATED 29 February 2012 -@set VERSION 1.3 +@set UPDATED 7 February 2013 +@set VERSION 1.4-rc2 @dircategory Data Compression @direntry @@ -50,7 +50,7 @@ This manual is for Lzlib (version @value{VERSION}, @value{UPDATED}). @end menu @sp 1 -Copyright @copyright{} 2009, 2010, 2011, 2012 Antonio Diaz Diaz. +Copyright @copyright{} 2009, 2010, 2011, 2012, 2013 Antonio Diaz Diaz. This manual is free documentation: you have unlimited permission to copy, distribute and modify it. @@ -134,7 +134,7 @@ sizes: @itemize @bullet @item Input compression buffer. Written to by the @samp{LZ_compress_write} function. Its size is two times the dictionary -size set with the @samp{LZ_compress_open} function or 128KiB, whichever +size set with the @samp{LZ_compress_open} function or 64KiB, whichever is larger. @item Output compression buffer. Read from by the @@ -187,11 +187,12 @@ Returns the largest valid match length limit [273]. @cindex compression functions These are the functions used to compress data. In case of error, all of -them return -1, except @samp{LZ_compress_open} whose return value must -be verified by calling @samp{LZ_compress_errno} before using it. +them return -1 or 0, for signed and unsigned return values respectively, +except @samp{LZ_compress_open} whose return value must be verified by +calling @samp{LZ_compress_errno} before using it. -@deftypefun {struct LZ_Encoder *} LZ_compress_open ( const int @var{dictionary_size}, const int @var{match_len_limit}, const long long @var{member_size} ) +@deftypefun {struct LZ_Encoder *} LZ_compress_open ( const int @var{dictionary_size}, const int @var{match_len_limit}, const unsigned long long @var{member_size} ) Initializes the internal stream state for compression and returns a pointer that can only be used as the @var{encoder} argument for the other LZ_compress functions, or a null pointer if the encoder could not @@ -216,7 +217,7 @@ ratios but longer compression times. size limit is 100kB. Small member size may degrade compression ratio, so use it only when needed. To produce a single-member data stream, give @var{member_size} a value larger than the amount of data to be produced, -for example LLONG_MAX. +for example INT64_MAX. @end deftypefun @@ -237,7 +238,7 @@ After all the produced compressed data has been read with @end deftypefun -@deftypefun int LZ_compress_restart_member ( struct LZ_Encoder * const @var{encoder}, const long long @var{member_size} ) +@deftypefun int LZ_compress_restart_member ( struct LZ_Encoder * const @var{encoder}, const unsigned long long @var{member_size} ) Use this function to start a new member, in a multi-member data stream. Call this function only after @samp{LZ_compress_member_finished} indicates that the current member has been fully read (with the @@ -278,10 +279,10 @@ not an error. @deftypefun int LZ_compress_write_size ( struct LZ_Encoder * const @var{encoder} ) The @samp{LZ_compress_write_size} function returns the maximum number of -bytes that can be inmediately written through the @samp{LZ_compress_write} +bytes that can be immediately written through the @samp{LZ_compress_write} function. -It is guaranteed that an inmediate call to @samp{LZ_compress_write} will +It is guaranteed that an immediate call to @samp{LZ_compress_write} will accept a @var{size} up to the returned number of bytes. @end deftypefun @@ -304,24 +305,24 @@ Otherwise it returns 0. @end deftypefun -@deftypefun {long long} LZ_compress_data_position ( struct LZ_Encoder * const @var{encoder} ) +@deftypefun {unsigned long long} LZ_compress_data_position ( struct LZ_Encoder * const @var{encoder} ) Returns the number of input bytes already compressed in the current member. @end deftypefun -@deftypefun {long long} LZ_compress_member_position ( struct LZ_Encoder * const @var{encoder} ) +@deftypefun {unsigned long long} LZ_compress_member_position ( struct LZ_Encoder * const @var{encoder} ) Returns the number of compressed bytes already produced, but perhaps not yet read, in the current member. @end deftypefun -@deftypefun {long long} LZ_compress_total_in_size ( struct LZ_Encoder * const @var{encoder} ) +@deftypefun {unsigned long long} LZ_compress_total_in_size ( struct LZ_Encoder * const @var{encoder} ) Returns the total number of input bytes already compressed. @end deftypefun -@deftypefun {long long} LZ_compress_total_out_size ( struct LZ_Encoder * const @var{encoder} ) +@deftypefun {unsigned long long} LZ_compress_total_out_size ( struct LZ_Encoder * const @var{encoder} ) Returns the total number of compressed bytes already produced, but perhaps not yet read. @end deftypefun @@ -332,8 +333,9 @@ perhaps not yet read. @cindex decompression functions These are the functions used to decompress data. In case of error, all -of them return -1, except @samp{LZ_decompress_open} whose return value -must be verified by calling @samp{LZ_decompress_errno} before using it. +of them return -1 or 0, for signed and unsigned return values +respectively, except @samp{LZ_decompress_open} whose return value must +be verified by calling @samp{LZ_decompress_errno} before using it. @deftypefun {struct LZ_Decoder *} LZ_decompress_open ( void ) @@ -410,10 +412,10 @@ not an error. @deftypefun int LZ_decompress_write_size ( struct LZ_Decoder * const @var{decoder} ) The @samp{LZ_decompress_write_size} function returns the maximum number -of bytes that can be inmediately written through the +of bytes that can be immediately written through the @samp{LZ_decompress_write} function. -It is guaranteed that an inmediate call to @samp{LZ_decompress_write} +It is guaranteed that an immediate call to @samp{LZ_decompress_write} will accept a @var{size} up to the returned number of bytes. @end deftypefun @@ -448,31 +450,31 @@ Returns the dictionary size of current member from member header. @end deftypefun -@deftypefun {unsigned int} LZ_decompress_data_crc ( struct LZ_Decoder * const @var{decoder} ) +@deftypefun {unsigned} LZ_decompress_data_crc ( struct LZ_Decoder * const @var{decoder} ) Returns the 32 bit Cyclic Redundancy Check of the data decompressed from the current member. The returned value is valid only when @samp{LZ_decompress_member_finished} returns 1. @end deftypefun -@deftypefun {long long} LZ_decompress_data_position ( struct LZ_Decoder * const @var{decoder} ) +@deftypefun {unsigned long long} LZ_decompress_data_position ( struct LZ_Decoder * const @var{decoder} ) Returns the number of decompressed bytes already produced, but perhaps not yet read, in the current member. @end deftypefun -@deftypefun {long long} LZ_decompress_member_position ( struct LZ_Decoder * const @var{decoder} ) +@deftypefun {unsigned long long} LZ_decompress_member_position ( struct LZ_Decoder * const @var{decoder} ) Returns the number of input bytes already decompressed in the current member. @end deftypefun -@deftypefun {long long} LZ_decompress_total_in_size ( struct LZ_Decoder * const @var{decoder} ) +@deftypefun {unsigned long long} LZ_decompress_total_in_size ( struct LZ_Decoder * const @var{decoder} ) Returns the total number of input bytes already decompressed. @end deftypefun -@deftypefun {long long} LZ_decompress_total_out_size ( struct LZ_Decoder * const @var{decoder} ) +@deftypefun {unsigned long long} LZ_decompress_total_out_size ( struct LZ_Decoder * const @var{decoder} ) Returns the total number of decompressed bytes already produced, but perhaps not yet read. @end deftypefun @@ -555,6 +557,11 @@ The value of @var{lz_errno} normally comes from a call to @chapter Data Format @cindex 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 + +@sp 1 In the diagram below, a box like this: @verbatim +---+ @@ -590,9 +597,7 @@ All multibyte values are stored in little endian order. A four byte string, identifying the lzip format, with the value "LZIP". @item VN (version number, 1 byte) -Just in case something needs to be modified in the future. Valid values -are 0 and 1. Version 0 files are deprecated. They can contain only one -member and lack the @samp{Member size} field. +Just in case something needs to be modified in the future. 1 for now. @item DS (coded dictionary size, 1 byte) Bits 4-0 contain the base 2 logarithm of the base dictionary size.@* @@ -612,8 +617,9 @@ CRC of the uncompressed original data. Size of the uncompressed original data. @item Member size (8 bytes) -Total size of the member, including header and trailer. This facilitates -safe recovery of undamaged members from multi-member files. +Total size of the member, including header and trailer. This field acts +as a distributed index, and facilitates safe recovery of undamaged +members from multi-member files. @end table |