License:
BSD style: see license.txt
Version:
Initial release: July 2007
author:
Daniel Keep
History:
Added support for "window bits", needed for Zip support.
- class
ZlibInput
: tango.io.device.Conduit.InputFilter;
- This input filter can be used to perform decompression of zlib streams.
- this(InputStream stream);
this(InputStream stream, int windowBits);
- Constructs a new zlib decompression filter. You need to pass in the
stream that the decompression filter will read from. If you are using
this filter with a conduit, the idiom to use is:
auto input = new ZlibInput(myConduit.input) ;
input.read(myContent);
The optional windowBits parameter is the base two logarithm of the
window size, and should be in the range 8-15, defaulting to 15 if not
specified. Additionally, the windowBits parameter may be negative to
indicate that zlib should omit the standard zlib header and trailer,
with the window size being -windowBits.
- uint
read
(void[] dst);
- Decompresses data from the underlying conduit into a target array.
Returns the number of bytes stored into dst, which may be less than
requested.
- InputStream
clear
();
- Clear any buffered content. No-op.
class
ZlibOutput
: tango.io.device.Conduit.OutputFilter;
This output filter can be used to perform compression of data into a zlib
stream.
- enum
Level
;
- This enumeration represents several pre-defined compression levels.
None instructs zlib to perform no compression whatsoever, and simply
store the data stream. Note that this actually expands the stream
slightly to accommodate the zlib stream metadata.
Fast instructs zlib to perform a minimal amount of compression, Best
indicates that you want the maximum level of compression and Normal
(the default level) is a compromise between the two. The exact
compression level Normal represents is determined by the underlying
zlib library, but is typically level 6.
Any integer between -1 and 9 inclusive may be used as a level,
although the symbols in this enumeration should suffice for most
use-cases.
- this(OutputStream stream, Level level = (Level).Normal);
this(OutputStream stream, Level level, int windowBits);
- Constructs a new zlib compression filter. You need to pass in the
stream that the compression filter will write to. If you are using
this filter with a conduit, the idiom to use is:
auto output = new ZlibOutput(myConduit.output);
output.write(myContent);
The optional windowBits parameter is the base two logarithm of the
window size, and should be in the range 8-15, defaulting to 15 if not
specified. Additionally, the windowBits parameter may be negative to
indicate that zlib should omit the standard zlib header and trailer,
with the window size being -windowBits.
- uint
write
(void[] src);
- Compresses the given data to the underlying conduit.
Returns the number of bytes from src that were compressed;
write
should always consume all data provided to it, although it may not be
immediately written to the underlying output stream.
- uint
written
();
- This read-only property returns the number of compressed bytes that
have been
written
to the underlying stream. Following a call to
either close or commit, this will contain the total compressed size of
the input data stream.
- void
close
();
- commit the output
- void
commit
();
- Purge any buffered content. Calling this will implicitly end the zlib
stream, so it should not be called until you are finished compressing
data. Any calls to either write or
commit
after a compression filter
has been committed will throw an exception.
class
ZlibClosedException
: tango.core.Exception.IOException;
This exception is thrown if you attempt to perform a read, write or flush
operation on a closed zlib filter stream. This can occur if the input
stream has finished, or an output stream was flushed.
class
ZlibException
: tango.core.Exception.IOException;
This exception is thrown when an error occurs in the underlying zlib
library. Where possible, it will indicate both the name of the error, and
any textural message zlib has provided.
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