Huffman Table APIs

Huffman Table APIs#

Functions#

Creation and Destruction of Huffman table#

qpl_status qpl_deflate_huffman_table_create(const qpl_huffman_table_type_e type, const qpl_path_t path, const allocator_t allocator, qpl_huffman_table_t *table_ptr)#

Creates a qpl_huffman_table_t object for deflate. Allocate and markup of internal structures.

Parameters:
Returns:

status from qpl_status

qpl_status qpl_huffman_only_table_create(const qpl_huffman_table_type_e type, const qpl_path_t path, const allocator_t allocator, qpl_huffman_table_t *table_ptr)#

Creates a qpl_huffman_table_t object for Huffman Only. Allocate and markup of internal structures.

Parameters:
Returns:

status from qpl_status

qpl_status qpl_huffman_table_destroy(qpl_huffman_table_t table)#

Destroy an qpl_huffman_table_t object. Deallocates internal structures.

Parameters:
Returns:

status from qpl_status

Initialization of Huffman table#

qpl_status qpl_huffman_table_init_with_triplets(qpl_huffman_table_t table, const qpl_huffman_triplet *const triplet_ptr, const uint32_t triplet_count)#

Initializes huffman table with provided triplets.

Parameters:

  • table – [inout] qpl_huffman_table_t object to init

  • triplet_ptr – [in] user defined triplet huffman codes

  • triplet_count – [in] huffman codes count

Returns:

status from qpl_status

qpl_status qpl_gather_deflate_statistics(uint8_t *source_ptr, const uint32_t source_length, qpl_histogram *histogram_ptr, const qpl_compression_levels level, const qpl_path_t path)#

Gathers deflate statistics (literals/lengths and offsets histogram)

Parameters:

  • source_ptr – [in] Pointer to source vector that should be processed

  • source_length – [in] Source vector length

  • histogram_ptr – [out] Pointer to histogram to be updated

  • level – [in] Level of compression algorithm

  • path – [in] Execution path

Returns:

One of statuses presented in the qpl_status

qpl_status qpl_huffman_table_init_with_histogram(qpl_huffman_table_t table, const qpl_histogram *const histogram_ptr)#

Initializes huffman table with provided histogram.

Parameters:

  • table – [inout] qpl_huffman_table_t object to init

  • histogram_ptr – [in] source statistics

Returns:

status from qpl_status

qpl_status qpl_huffman_table_init_with_other(qpl_huffman_table_t table, const qpl_huffman_table_t other)#

Initializes huffman table with information from another table.

Parameters:
Returns:

status from qpl_status

Serialization APIs#

qpl_status qpl_huffman_table_get_serialized_size(const qpl_huffman_table_t table, const serialization_options_t options, size_t *const size_ptr)#

API to get size of the table to be serialized.

Note

Serialization is only supported for serialization_raw format.

Parameters:
Returns:

status from qpl_status

qpl_status qpl_huffman_table_serialize(const qpl_huffman_table_t table, uint8_t *const dump_buffer_ptr, const size_t dump_buffer_size, const serialization_options_t options)#

Serializes qpl_huffman_table_t object.

Note

Serialization is only supported for serialization_raw format.

Parameters:
Returns:

status from qpl_status

qpl_status qpl_huffman_table_deserialize(const uint8_t *const dump_buffer_ptr, const size_t dump_buffer_size, allocator_t allocator, qpl_huffman_table_t *table_ptr)#

Deserializes previously serialized huffman table.

Parameters:

  • dump_buffer_ptr – [in] serialized object buffer

  • dump_buffer_size – [in] serialized object buffer size

  • allocator – [in] allocator that must be used

  • table_ptr – [out] output parameter for created object

Returns:

status from qpl_status

qpl_status qpl_huffman_table_get_type(const qpl_huffman_table_t table, qpl_huffman_table_type_e *const type_ptr)#

Returns type of qpl_huffman_table_t.

Parameters:
Returns:

status from qpl_status

Types#

typedef struct qpl_huffman_table *qpl_huffman_table_t#

Special data type that is an opaque pointer to unified compression/decompression table.

Enums#

enum qpl_huffman_table_type_e#

Type used to specify whether Huffman table would store compression, decompression or both tables internally.

Values:

enumerator combined_table_type#

qpl_huffman_table_t contains both tables

enumerator compression_table_type#

qpl_huffman_table_t contains compression table only

enumerator decompression_table_type#

qpl_huffman_table_t contains decompression table only

enum qpl_serialization_format_e#

Describes how to perform serialization

Values:

enumerator serialization_compact#

More compact representation, useful for saving up memory on the disk

enumerator serialization_raw#

Faster but more straightforward implementation, use to save speed of serialization/deserialization in case high load

Structures#

struct qpl_huffman_triplet#

Structure for intermediate representation of Huffman token.

Public Members

uint8_t value#

Encoded value

uint8_t code_length#

Length of Huffman code for given value

uint16_t code#

Huffman code for given value

struct qpl_histogram#

Structure that represents histogram of literals, lengths and offsets symbols.

Public Members

uint32_t literal_lengths[QPL_LITERALS_MATCHES_TABLE_SIZE]#

Combined histogram for literals and match lengths tokens

uint32_t reserved_literal_lengths[2U]#

Reserved match lengths tokens

uint32_t distances[QPL_DEFAULT_OFFSETS_NUMBER]#

Histogram for distance tokens

uint32_t reserved_distances[2U]#

Reserved distance tokens

struct serialization_options_t#

Describes serialization options.

Public Members

qpl_serialization_format_e format#

qpl_serialization_format_e of serialized object

serialization_flags_t flags#

Advanced serialization options, placeholder for later