Function compression_encode_buffer

pub unsafe extern "C" fn compression_encode_buffer(
    dst_buffer: *mut uint8_t,
    dst_size: size_t,
    src: *const uint8_t,
    src_size: size_t,
    scratch_buffer: *mut c_void,
    algorithm: compression_algorithm,
) -> size_t

Compresses the contents of a source buffer into a destination buffer.

Arguments

• dst_buffer - Pointer to the buffer that receives the compressed data.
• dst_size - Size of the destination buffer in bytes.
• src - Pointer to a buffer containing all of the source data.
• src_size - Size of the data in the source buffer in bytes.
• scratch_buffer - If scratch_buffer is not crate::objective_c_runtime::nil, this parameter is a pointer to a buffer that the function uses for scratch purposes. The size of this buffer must be at least the size returned by a previous call to compression_encode_scratch_buffer_size.If scratch_buffer is crate::objective_c_runtime::nil, the function creates and manages its own scratch space, but with a possible performance hit.
• algorithm - Set to the desired algorithm: compression_algorithm::LZ4, compression_algorithm::ZLIB, compression_algorithm::LZMA, or compression_algorithm::LZFSE.

Examples

use rust_macios::{compression::{compression_algorithm, compression_encode_buffer}, kernel::size_t};

let source_string = r#"
    Lorem ipsum dolor sit amet consectetur adipiscing elit mi
    nibh ornare proin blandit diam ridiculus, faucibus mus
    dui eu vehicula nam donec dictumst sed vivamus bibendum
    aliquet efficitur. Felis imperdiet sodales dictum morbi
    vivamus augue dis duis aliquet velit ullamcorper porttitor,
    lobortis dapibus hac purus aliquam natoque iaculis blandit
    montes nunc pretium."#;

let source_buffer = source_string.as_bytes();

let mut dest_buffer = vec![0; source_string.len()];

let algorithm = compression_algorithm::LZFSE;

let compressed_size = unsafe {
    compression_encode_buffer(
        dest_buffer.as_mut_ptr(),
        source_string.len() as size_t,
        source_buffer.as_ptr(),
        source_string.len() as size_t,
        std::ptr::null_mut(),
        algorithm,
    )
};

assert!(compressed_size != 0, "Encoding failed.");

Returns

The number of bytes written to the destination buffer after compressing the input. If the funtion can’t compress the entire input to fit into the provided destination buffer, or an error occurs, 0 is returned.