compression.h File Reference

📦 Network Packet Compression Utilities More...

Go to the source code of this file.

Data Structures
struct	compression_workspace_t
	Owns the temporary storage used by compression workspace. The data pointers and size or cursor fields describe the live portion of the allocation; callers must use the type's cleanup path when the buffer or queue is no longer needed. Output is borrowed until the next call or destruction; never queue it without copying. The caller serializes access to the workspace. More...

Macros
Compression Settings
#define	COMPRESSION_RATIO_THRESHOLD   0.8f
	Compression ratio threshold - only use if <80% original size.
#define	COMPRESSION_MIN_SIZE   1024
	Minimum packet size to attempt compression (1KB).

Functions
asciichat_error_t	compress_data (const void *input, size_t input_size, void **output, size_t *output_size, int compression_level)
	Compress data using zstd with configurable compression level.
asciichat_error_t	decompress_data (const void *input, size_t input_size, void *output, size_t output_size)
	Decompress data using zstd.
asciichat_error_t	decompress_data_exact (const void *input, size_t input_size, void *output, size_t expected_size)
bool	should_compress (size_t original_size, size_t compressed_size)
	Determine if compression should be used for given data sizes.
asciichat_error_t	compress_workspace (compression_workspace_t *workspace, const void *input, size_t size, int level)
void	compression_workspace_destroy (compression_workspace_t *workspace)

Detailed Description

📦 Network Packet Compression Utilities

Definition in file compression.h.

Function Documentation

compress_workspace()

asciichat_error_t compress_workspace	(	compression_workspace_t *	workspace,
		const void *	input,
		size_t	size,
		int	level )

Definition at line 133 of file compression.c.

                                                                                                                    {
  ASCII_OTEL_SCOPE(ZSTD_COMPRESS_WORKSPACE);
  ASCII_OTEL_ATTR_STRING("compression.algorithm", "zstd");
  ASCII_OTEL_ATTR_STRING("compression.library.version", ZSTD_versionString());
  ASCII_OTEL_ATTR_INT("compression.level", level);
  ASCII_OTEL_ATTR_INT("compression.input.size", (int64_t)size);
  if (!workspace || !input || !size || level < 1 || level > 9)
    return SET_ERRNO(ERROR_INVALID_PARAM, "Invalid compression workspace request");
  workspace->output.length = 0;
  size_t bound = ZSTD_compressBound(size);
  if (!bound || bound > 256 * 1024 * 1024)
    return SET_ERRNO(ERROR_INVALID_PARAM, "Compression workspace exceeds maximum size");
  asciichat_error_t result = buffer_workspace_reserve(&workspace->output, NULL, bound);
  if (result != ASCIICHAT_OK)
    return result;
  if (!workspace->codec)
    workspace->codec = ZSTD_createCCtx();
  if (!workspace->codec)
    return SET_ERRNO(ERROR_MEMORY, "Cannot create compression context");
  size_t written = ZSTD_compressCCtx(workspace->codec, workspace->output.data, buffer_capacity(workspace->output.data),
                                     input, size, level);
  if (ZSTD_isError(written))
    return SET_ERRNO(ERROR_GENERAL, "Compression failed: %s", ZSTD_getErrorName(written));
  workspace->output.length = written;
  result = buffer_set_size(workspace->output.data, written);
  if (result == ASCIICHAT_OK) {
    ASCII_OTEL_ATTR_INT("compression.output.size", (int64_t)written);
    ASCII_OTEL_ATTR_INT("compression.ratio.permille", (int64_t)(1000.0 * (double)written / (double)size));
    compression_measure(size, written, true);
  }
  return result;
}

References ASCII_OTEL_ATTR_INT, ASCII_OTEL_ATTR_STRING, ASCII_OTEL_SCOPE, ASCIICHAT_OK, buffer_capacity(), buffer_set_size(), buffer_workspace_reserve(), compression_workspace_t::codec, buffer_workspace_t::data, ERROR_GENERAL, ERROR_INVALID_PARAM, ERROR_MEMORY, buffer_workspace_t::length, compression_workspace_t::output, and SET_ERRNO.

Referenced by acip_send_ascii_frame_contract().

compression_workspace_destroy()

void compression_workspace_destroy

(

compression_workspace_t *

workspace

)

Definition at line 166 of file compression.c.

                                                                       {
  if (!workspace)
    return;
  ZSTD_freeCCtx(workspace->codec);
  workspace->codec = NULL;
  buffer_workspace_destroy(&workspace->output);
}

References buffer_workspace_destroy(), compression_workspace_t::codec, and compression_workspace_t::output.

Referenced by acip_frame_workspace_destroy().