LZSS based compression HAL API. More...

#include <stdbool.h>
#include <stdint.h>
#include <stddef.h>

Data Structures
struct	CompressConfigHeatshrink
	Configuration for heatshrink compression. More...

Typedefs
typedef struct CompressIcon	CompressIcon
	Compress Icon control structure.

typedef struct Compress	Compress
	Compress control structure.

typedef int32_t(*	CompressIoCallback) (void context, uint8_t buffer, size_t size)
	I/O callback for streamed compression/decompression.

typedef struct CompressStreamDecoder	CompressStreamDecoder
	CompressStreamDecoder control structure.

Enumerations
enum	CompressType { CompressTypeHeatshrink = 0 }
	Supported compression types.

Functions
CompressIcon *	compress_icon_alloc (size_t decode_buf_size)
	Initialize icon compressor.

void	compress_icon_free (CompressIcon *instance)
	Free icon compressor.

void	compress_icon_decode (CompressIcon instance, const uint8_t icon_data, uint8_t **output)
	Decompress icon.

Compress *	compress_alloc (CompressType type, const void *config)
	Allocate encoder and decoder.

void	compress_free (Compress *compress)
	Free encoder and decoder.

bool	compress_encode (Compress compress, uint8_t data_in, size_t data_in_size, uint8_t data_out, size_t data_out_size, size_t data_res_size)
	Encode data.

bool	compress_decode (Compress compress, uint8_t data_in, size_t data_in_size, uint8_t data_out, size_t data_out_size, size_t data_res_size)
	Decode data.

bool	compress_decode_streamed (Compress compress, CompressIoCallback read_cb, void read_context, CompressIoCallback write_cb, void *write_context)
	Decompress streamed data.

CompressStreamDecoder *	compress_stream_decoder_alloc (CompressType type, const void config, CompressIoCallback read_cb, void read_context)
	Allocate stream decoder.

void	compress_stream_decoder_free (CompressStreamDecoder *instance)
	Free stream decoder.

bool	compress_stream_decoder_read (CompressStreamDecoder instance, uint8_t data_out, size_t data_out_size)
	Read uncompressed data chunk from stream decoder.

bool	compress_stream_decoder_seek (CompressStreamDecoder *instance, size_t position)
	Seek to position in uncompressed data stream.

size_t	compress_stream_decoder_tell (CompressStreamDecoder *instance)
	Get current position in uncompressed data stream.

bool	compress_stream_decoder_rewind (CompressStreamDecoder *instance)
	Reset stream decoder to the beginning.

Variables
const CompressConfigHeatshrink	compress_config_heatshrink_default
	Default configuration for heatshrink compression.

Detailed Description

LZSS based compression HAL API.

Typedef Documentation

◆ CompressIoCallback

typedef int32_t(* CompressIoCallback) (void *context, uint8_t *buffer, size_t size)

I/O callback for streamed compression/decompression.

Parameters

context	user context
buffer	buffer to read/write
size	size of buffer

Returns: number of bytes read/written, 0 on end of stream, negative on error

Function Documentation

◆ compress_alloc()

Compress * compress_alloc	(	CompressType	type,
		const void *	config )

Allocate encoder and decoder.

Parameters

	type	Compression type
[in]	config	Configuration for compression, specific to type

Returns: Compress instance

◆ compress_decode()

bool compress_decode	(	Compress *	compress,
		uint8_t *	data_in,
		size_t	data_in_size,
		uint8_t *	data_out,
		size_t	data_out_size,
		size_t *	data_res_size )

Decode data.

Parameters

	compress	Compress instance
	data_in	pointer to input data
	data_in_size	size of input data
	data_out	maximum size of output data
[in]	data_out_size	The data out size
	data_res_size	pointer to result output data size

Note: Expects compressed stream with a header, as produced by compress_encode.

Returns: true on success

◆ compress_decode_streamed()

bool compress_decode_streamed	(	Compress *	compress,
		CompressIoCallback	read_cb,
		void *	read_context,
		CompressIoCallback	write_cb,
		void *	write_context )

Decompress streamed data.

Parameters

compress	Compress instance
read_cb	read callback
read_context	read callback context
write_cb	write callback
write_context	write callback context

Note: Does not expect a header, just compressed data stream.

Returns: true on success

◆ compress_encode()

bool compress_encode	(	Compress *	compress,
		uint8_t *	data_in,
		size_t	data_in_size,
		uint8_t *	data_out,
		size_t	data_out_size,
		size_t *	data_res_size )

Encode data.

Parameters

	compress	Compress instance
	data_in	pointer to input data
	data_in_size	size of input data
	data_out	maximum size of output data
[in]	data_out_size	The data out size
	data_res_size	pointer to result output data size

Note: Prepends compressed stream with a header. If data is not compressible, it will be stored as is after the header.

Returns: true on success

◆ compress_free()

void compress_free ( Compress * compress )

Free encoder and decoder.

Parameters

compress Compress instance

◆ compress_icon_alloc()

CompressIcon * compress_icon_alloc ( size_t decode_buf_size )

Initialize icon compressor.

Parameters

[in] decode_buf_size The icon buffer size for decoding. Ensure that it's big enough for any icons that you are planning to decode with it.

Returns: Compress Icon instance

◆ compress_icon_decode()

void compress_icon_decode	(	CompressIcon *	instance,
		const uint8_t *	icon_data,
		uint8_t **	output )

Decompress icon.

Warning: output pointer set by this function is valid till next compress_icon_decode or compress_icon_free call

Parameters

	instance	The Compress Icon instance
	icon_data	pointer to icon data.
[in]	output	pointer to decoded buffer pointer. Data in buffer is valid till next call. If icon data was not compressed, pointer within icon_data is returned

◆ compress_icon_free()

void compress_icon_free ( CompressIcon * instance )

Free icon compressor.

Parameters

instance The Compress Icon instance

◆ compress_stream_decoder_alloc()

CompressStreamDecoder * compress_stream_decoder_alloc	(	CompressType	type,
		const void *	config,
		CompressIoCallback	read_cb,
		void *	read_context )

Allocate stream decoder.

Parameters

	type	Compression type
[in]	config	Configuration for compression, specific to type
	read_cb	The read callback for input (compressed) data
	read_context	The read context

Returns: CompressStreamDecoder instance

◆ compress_stream_decoder_free()

void compress_stream_decoder_free ( CompressStreamDecoder * instance )

Free stream decoder.

Parameters

instance The CompressStreamDecoder instance

◆ compress_stream_decoder_read()

bool compress_stream_decoder_read	(	CompressStreamDecoder *	instance,
		uint8_t *	data_out,
		size_t	data_out_size )

Read uncompressed data chunk from stream decoder.

Parameters

	instance	The CompressStreamDecoder instance
	data_out	The data out
[in]	data_out_size	The data out size

Returns: true on success

◆ compress_stream_decoder_rewind()

bool compress_stream_decoder_rewind ( CompressStreamDecoder * instance )

Reset stream decoder to the beginning.

Warning: Read callback must be repositioned by caller separately

Parameters

instance The CompressStreamDecoder instance

Returns: true on success

◆ compress_stream_decoder_seek()

bool compress_stream_decoder_seek	(	CompressStreamDecoder *	instance,
		size_t	position )

Seek to position in uncompressed data stream.

Parameters

	instance	The CompressStreamDecoder instance
[in]	position	The position

Returns: true on success

Warning: Backward seeking is not supported

◆ compress_stream_decoder_tell()

size_t compress_stream_decoder_tell ( CompressStreamDecoder * instance )

Get current position in uncompressed data stream.

Parameters

instance The CompressStreamDecoder instance

Returns: current position

Variable Documentation

◆ compress_config_heatshrink_default

const CompressConfigHeatshrink compress_config_heatshrink_default

extern

Default configuration for heatshrink compression.

Used for image assets.

Data Structures

Typedefs

Enumerations

Functions

Variables

Detailed Description

Typedef Documentation

◆ CompressIoCallback

Function Documentation

◆ compress_alloc()

◆ compress_decode()

◆ compress_decode_streamed()

◆ compress_encode()

◆ compress_free()

◆ compress_icon_alloc()

◆ compress_icon_decode()

◆ compress_icon_free()

◆ compress_stream_decoder_alloc()

◆ compress_stream_decoder_free()

◆ compress_stream_decoder_read()

◆ compress_stream_decoder_rewind()

◆ compress_stream_decoder_seek()

◆ compress_stream_decoder_tell()

Variable Documentation

◆ compress_config_heatshrink_default