ddn.compressor.deflate

ddn.compressor.deflate

CompressionProvider for DEFLATE with zlib wrapper format (RFC 1950) for ddn.api.compressor. Uses the pure D zlib implementation from ddn.compressor.zlib. Registers as provider "ddn" for format "deflate_zlib".

This implements the most common DEFLATE format used in PNG, ZIP, HTTP, etc. The zlib wrapper adds a 2-byte header and 4-byte Adler-32 checksum.

  • Supports both streaming and block compression.
  • Fully DDoc-documented.
  • All public functions and types have unittests.

    Copyright

    BSD-3-Clause
class DeflateCompressor DeflateDecompressor
fn makeDeflateCompressor makeDeflateDecompressor toZFlush toZLevel toZStrategy

Module Initializers 1

shared static this()

Types 2

classDeflateCompressor : Compressor

DEFLATE compressor using the pure-D zlib engine (ddn.compressor.zlib).

Fields
private CompressionOptions _opts
private OutputSink _sink
private bool _finished
private z_stream _zs
private bool _dictSet
private ubyte[] _dictionary
private ulong _bytesIn
private ulong _bytesOut
private int _windowBits
Methods
CompressionOptions options() @property constReturn the options used to create this compressor.
void setOutputSink(OutputSink sink)Set the output sink delegate that will receive produced compressed chunks.
void setProgressCallback(ProgressCallback callback)Set an optional progress callback.
ulong bytesInTotal() @property constTotal uncompressed bytes consumed since last reset.
ulong bytesOutTotal() @property constTotal compressed bytes produced since last reset.
void write(const(ubyte)[] data)Feed more uncompressed data. Throws if finish() was already called or output sink is not set.
void flush(FlushMode mode = FlushMode.SYNC)Flush pending output according to the provided `FlushMode`. - sync -> Z_SYNC_FLUSH - full -> Z_FULL_FLUSH
void finish()Finalize the stream and emit trailer. No further writes are allowed afterwards.
void reset()Reset the compression stream to initial state (options retained).
bool setDictionary(const(ubyte)[] dict)Set dictionary if supported. Returns: true if accepted, false if not supported.
bool isFinished() @property constReturns true if finish() has been called and the stream is closed for further writes.
Constructors
this(CompressionOptions opts)Create a compressor with provided options.
Destructors
~thisEnsure zlib stream is ended.
classDeflateDecompressor : Decompressor

DEFLATE decompressor using the pure-D zlib engine (ddn.compressor.zlib).

Fields
private DecompressionOptions _opts
private OutputSink _sink
private bool _finished
private z_stream _zs
private bool _dictSet
private ubyte[] _dictionary
private bool _sawStreamEnd
private ulong _bytesIn
private ulong _bytesOut
private int _windowBits
Methods
DecompressionOptions options() @property constReturn the options used to create this decompressor.
void setOutputSink(OutputSink sink)Set the output sink delegate that will receive produced decompressed chunks.
void setProgressCallback(ProgressCallback callback)Set an optional progress callback.
ulong bytesInTotal() @property constTotal compressed bytes consumed since last reset.
ulong bytesOutTotal() @property constTotal decompressed bytes produced since last reset.
private bool applyConfiguredDictionary()Apply the configured dictionary when the inflate stream requests one.
void write(const(ubyte)[] data)Feed more compressed data. Throws if finish() was already called or output sink is not set.
void finish()Signal end-of-input; allows the decompressor to validate checksums and emit any trailing bytes.
void reset()Reset the decompression stream to initial state (options retained).
bool setDictionary(const(ubyte)[] dict)Configure a dictionary for streams that declare FDICT.
bool isFinished() @property constReturns true if finish() has been called and the stream is closed for further writes.
Constructors
this(DecompressionOptions opts)Create a decompressor with provided options.
Destructors
~this

Functions 5

private fnint toZLevel(CompressionOptions opts)Map ddn CompressionLevel to zlib level.
private fnint toZStrategy(CompressionOptions opts)Map ddn CompressionStrategy to zlib strategy.
private fnint toZFlush(FlushMode mode)Map ddn FlushMode to zlib flush constant.
fnCompressor makeDeflateCompressor(CompressionOptions opts)Factory function that constructs a `DeflateCompressor`.
fnDecompressor makeDeflateDecompressor(DecompressionOptions opts)Factory function that constructs a `DeflateDecompressor`.