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authorDaniel Baumann <mail@daniel-baumann.ch>2015-11-07 13:33:30 +0000
committerDaniel Baumann <mail@daniel-baumann.ch>2015-11-07 13:33:30 +0000
commit447d8df5e4c1f6c985791cb3fea2922fcc1cfbee (patch)
treeec719a03bcff2f05604f2ae3c9604c85501944ed /doc
parentAdding upstream version 0.3. (diff)
downloadlzlib-447d8df5e4c1f6c985791cb3fea2922fcc1cfbee.tar.xz
lzlib-447d8df5e4c1f6c985791cb3fea2922fcc1cfbee.zip
Adding upstream version 0.4.upstream/0.4
Signed-off-by: Daniel Baumann <mail@daniel-baumann.ch>
Diffstat (limited to '')
-rw-r--r--doc/lzlib.info104
-rw-r--r--doc/lzlib.texinfo79
2 files changed, 133 insertions, 50 deletions
diff --git a/doc/lzlib.info b/doc/lzlib.info
index 28aea4d..fff59c2 100644
--- a/doc/lzlib.info
+++ b/doc/lzlib.info
@@ -12,12 +12,13 @@ File: lzlib.info, Node: Top, Next: Introduction, Up: (dir)
Lzlib
*****
-This manual is for Lzlib (version 0.3, 3 May 2009).
+This manual is for Lzlib (version 0.4, 3 June 2009).
* Menu:
* Introduction:: Purpose and features of Lzlib
* Library Version:: Checking library version
+* Buffering:: Sizes of Lzlib's buffers
* Compression Functions:: Descriptions of the compression functions
* Decompression Functions:: Descriptions of the decompression functions
* Error Codes:: Meaning of codes returned by functions
@@ -38,8 +39,8 @@ File: lzlib.info, Node: Introduction, Next: Library Version, Prev: Top, Up:
1 Introduction
**************
-The lzlib compression library provides in-memory LZMA compression and
-decompression functions, including integrity checking of the
+Lzlib is a data compression library providing in-memory LZMA compression
+and decompression functions, including integrity checking of the
uncompressed data. The compressed data format used by the library is the
lzip format.
@@ -68,7 +69,7 @@ Igor Pavlov. For a description of the LZMA algorithm, see the Lzip
manual.

-File: lzlib.info, Node: Library Version, Next: Compression Functions, Prev: Introduction, Up: Top
+File: lzlib.info, Node: Library Version, Next: Buffering, Prev: Introduction, Up: Top
2 Library Version
*****************
@@ -88,9 +89,37 @@ application.
error( "bad library version" );

-File: lzlib.info, Node: Compression Functions, Next: Decompression Functions, Prev: Library Version, Up: Top
+File: lzlib.info, Node: Buffering, Next: Compression Functions, Prev: Library Version, Up: Top
-3 Compression Functions
+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 as large as the dictionary size.
+Finally, for security 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 `LZ_compress_write'
+ function. Its size is two times the dictionary size set with the
+ `LZ_compress_open' function or 128KiB, whichever is larger.
+
+ * Output compression buffer. Read from by the `LZ_compress_read'
+ function. Its size is 64KiB.
+
+ * Input decompression buffer. Written to by the
+ `LZ_decompress_write' function. Its size is 64KiB.
+
+ * Output decompression buffer. Read from by the `LZ_decompress_read'
+ function. Its size is the dictionary size set with the
+ `LZ_decompress_open' function or 64KiB, whichever is larger.
+
+
+File: lzlib.info, Node: Compression Functions, Next: Decompression Functions, Prev: Buffering, Up: Top
+
+4 Compression Functions
***********************
These are the functions used to compress data. In case of error, all of
@@ -123,6 +152,13 @@ verified by calling `LZ_compress_errno' before using it.
stream, give MEMBER_SIZE a value larger than the amount of data to
be produced, for example LLONG_MAX.
+ -- Function: int LZ_compress_restart_member ( void * const ENCODER,
+ const 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 `LZ_compress_read' function).
+
-- Function: int LZ_compress_close ( void * const ENCODER )
Frees all dynamically allocated data structures for this stream.
This function discards any unprocessed input and does not flush
@@ -133,17 +169,11 @@ verified by calling `LZ_compress_errno' before using it.
Use this function to tell `lzlib' that all the data for this stream
has already been written (with the `LZ_compress_write' function).
- -- Function: int LZ_compress_finish_member ( void * const ENCODER )
- Use this function to tell `lzlib' that all the data for the current
- member, in a multimember data stream, has already been written
- (with the `LZ_compress_write' function).
-
- -- Function: int LZ_compress_restart_member ( void * const ENCODER,
- const 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 `LZ_compress_read' function).
+ -- Function: int LZ_compress_sync_flush ( void * const ENCODER )
+ Use this function to make available to `LZ_compress_read' all the
+ data already written with the `LZ_compress_write' function.
+ Repeated use of `LZ_compress_sync_flush' may degrade compression
+ ratio, so use it only when needed.
-- Function: int LZ_compress_read ( void * const ENCODER, uint8_t *
const BUFFER, const int SIZE )
@@ -165,6 +195,14 @@ verified by calling `LZ_compress_errno' before using it.
might be less than SIZE. Note that writing less than SIZE bytes is
not an error.
+ -- Function: int LZ_compress_write_size ( void * const ENCODER )
+ The `LZ_compress_write_size' function returns the maximum number of
+ bytes that can be inmediately written through the
+ `LZ_compress_write' function.
+
+ It is guaranteed that an inmediate call to `LZ_compress_write' will
+ accept a SIZE up to the returned number of bytes.
+
-- Function: enum LZ_errno LZ_compress_errno ( void * const ENCODER )
Returns the current error code for ENCODER (*note Error Codes::)
@@ -199,7 +237,7 @@ verified by calling `LZ_compress_errno' before using it.

File: lzlib.info, Node: Decompression Functions, Next: Error Codes, Prev: Compression Functions, Up: Top
-4 Decompression Functions
+5 Decompression Functions
*************************
These are the functions used to decompress data. In case of error, all
@@ -275,7 +313,7 @@ be verified by calling `LZ_decompress_errno' before using it.

File: lzlib.info, Node: Error Codes, Next: Data Format, Prev: Decompression Functions, Up: Top
-5 Error Codes
+6 Error Codes
*************
Most library functions return -1 to indicate that they have failed. But
@@ -286,7 +324,7 @@ what kind of error it was, you need to verify the error code by calling
Library functions do not 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
-zero, and you should not use `LZ_(de)compress_errno' to determine
+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'.
@@ -327,7 +365,7 @@ whether a call failed. If the call failed, then you can examine

File: lzlib.info, Node: Data Format, Next: Examples, Prev: Error Codes, Up: Top
-6 Data Format
+7 Data Format
*************
In the diagram below, a box like this:
@@ -389,7 +427,7 @@ with no additional information before, between, or after them.

File: lzlib.info, Node: Examples, Next: Problems, Prev: Data Format, Up: Top
-7 A small tutorial with examples
+8 A small tutorial with examples
********************************
This chaper shows the order in which the library functions should be
@@ -437,7 +475,7 @@ Example 3: Multimember compression (MEMBER_SIZE < total output).

File: lzlib.info, Node: Problems, Next: Concept Index, Prev: Examples, Up: Top
-8 Reporting Bugs
+9 Reporting Bugs
****************
There are probably bugs in Lzlib. There are certainly errors and
@@ -459,6 +497,7 @@ Concept Index
* Menu:
+* buffering: Buffering. (line 6)
* bugs: Problems. (line 6)
* compression functions: Compression Functions. (line 6)
* data format: Data Format. (line 6)
@@ -474,14 +513,15 @@ Concept Index

Tag Table:
Node: Top219
-Node: Introduction968
-Node: Library Version2428
-Node: Compression Functions3085
-Node: Decompression Functions8178
-Node: Error Codes11616
-Node: Data Format13551
-Node: Examples15518
-Node: Problems16940
-Node: Concept Index17510
+Node: Introduction1010
+Node: Library Version2477
+Node: Buffering3122
+Node: Compression Functions4229
+Node: Decompression Functions9731
+Node: Error Codes13169
+Node: Data Format15105
+Node: Examples17072
+Node: Problems18494
+Node: Concept Index19064

End Tag Table
diff --git a/doc/lzlib.texinfo b/doc/lzlib.texinfo
index 69d96d4..044bd04 100644
--- a/doc/lzlib.texinfo
+++ b/doc/lzlib.texinfo
@@ -5,8 +5,8 @@
@finalout
@c %**end of header
-@set UPDATED 3 May 2009
-@set VERSION 0.3
+@set UPDATED 3 June 2009
+@set VERSION 0.4
@dircategory Data Compression
@direntry
@@ -34,6 +34,7 @@ This manual is for Lzlib (version @value{VERSION}, @value{UPDATED}).
@menu
* Introduction:: Purpose and features of Lzlib
* Library Version:: Checking library version
+* Buffering:: Sizes of Lzlib's buffers
* Compression Functions:: Descriptions of the compression functions
* Decompression Functions:: Descriptions of the decompression functions
* Error Codes:: Meaning of codes returned by functions
@@ -54,8 +55,8 @@ to copy, distribute and modify it.
@chapter Introduction
@cindex introduction
-The lzlib compression library provides in-memory LZMA compression and
-decompression functions, including integrity checking of the
+Lzlib is a data compression library providing in-memory LZMA compression
+and decompression functions, including integrity checking of the
uncompressed data. The compressed data format used by the library is the
lzip format.
@@ -106,6 +107,37 @@ if( LZ_version()[0] != LZ_version_string[0] )
@end example
+@node Buffering
+@chapter Buffering
+@cindex 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 as large as the dictionary size.
+Finally, for security reasons, lzlib uses two more internal buffers.
+
+These are the four buffers used by lzlib, and their guaranteed minimum
+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
+is larger.
+
+@item Output compression buffer. Read from by the
+@samp{LZ_compress_read} function. Its size is 64KiB.
+
+@item Input decompression buffer. Written to by the
+@samp{LZ_decompress_write} function. Its size is 64KiB.
+
+@item Output decompression buffer. Read from by the
+@samp{LZ_decompress_read} function. Its size is the dictionary size set
+with the @samp{LZ_decompress_open} function or 64KiB, whichever is
+larger.
+@end itemize
+
+
@node Compression Functions
@chapter Compression Functions
@cindex compression functions
@@ -142,6 +174,14 @@ for example LLONG_MAX.
@end deftypefun
+@deftypefun int LZ_compress_restart_member ( void * const @var{encoder}, const long long @var{member_size} )
+Use this function to start a new member, in a multimember data stream.
+Call this function only after @samp{LZ_compress_member_finished}
+indicates that the current member has been fully read (with the
+@samp{LZ_compress_read} function).
+@end deftypefun
+
+
@deftypefun int LZ_compress_close ( void * const @var{encoder} )
Frees all dynamically allocated data structures for this stream. This
function discards any unprocessed input and does not flush any pending
@@ -156,18 +196,11 @@ has already been written (with the @samp{LZ_compress_write} function).
@end deftypefun
-@deftypefun int LZ_compress_finish_member ( void * const @var{encoder} )
-Use this function to tell @samp{lzlib} that all the data for the current
-member, in a multimember data stream, has already been written (with the
-@samp{LZ_compress_write} function).
-@end deftypefun
-
-
-@deftypefun int LZ_compress_restart_member ( void * const @var{encoder}, const long long @var{member_size} )
-Use this function to start a new member, in a multimember data stream.
-Call this function only after @samp{LZ_compress_member_finished}
-indicates that the current member has been fully read (with the
-@samp{LZ_compress_read} function).
+@deftypefun int LZ_compress_sync_flush ( void * const @var{encoder} )
+Use this function to make available to @samp{LZ_compress_read} all the
+data already written with the @samp{LZ_compress_write} function.
+Repeated use of @samp{LZ_compress_sync_flush} may degrade compression
+ratio, so use it only when needed.
@end deftypefun
@@ -194,6 +227,16 @@ not an error.
@end deftypefun
+@deftypefun int LZ_compress_write_size ( void * 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}
+function.
+
+It is guaranteed that an inmediate call to @samp{LZ_compress_write} will
+accept a @var{size} up to the returned number of bytes.
+@end deftypefun
+
+
@deftypefun {enum LZ_errno} LZ_compress_errno ( void * const @var{encoder} )
Returns the current error code for @var{encoder} (@pxref{Error Codes})
@end deftypefun
@@ -340,8 +383,8 @@ what kind of error it was, you need to verify the error code by calling
Library functions do not change the value returned by
@samp{LZ_(de)compress_errno} when they succeed; thus, the value returned
by @samp{LZ_(de)compress_errno} after a successful call is not
-necessarily zero, and you should not use @samp{LZ_(de)compress_errno} to
-determine whether a call failed. If the call failed, then you can
+necessarily LZ_ok, and you should not use @samp{LZ_(de)compress_errno}
+to determine whether a call failed. If the call failed, then you can
examine @samp{LZ_(de)compress_errno}.
The error codes are defined in the header file @samp{lzlib.h}.