zstd_sys

Function ZSTD_createCDict

source
pub unsafe extern "C" fn ZSTD_createCDict(
    dictBuffer: *const c_void,
    dictSize: usize,
    compressionLevel: c_int,
) -> *mut ZSTD_CDict
Expand description

ZSTD_createCDict() : When compressing multiple messages or blocks using the same dictionary, it’s recommended to digest the dictionary only once, since it’s a costly operation. ZSTD_createCDict() will create a state from digesting a dictionary. The resulting state can be used for future compression operations with very limited startup cost. ZSTD_CDict can be created once and shared by multiple threads concurrently, since its usage is read-only. @dictBuffer can be released after ZSTD_CDict creation, because its content is copied within CDict. Note 1 : Consider experimental function ZSTD_createCDict_byReference() if you prefer to not duplicate @dictBuffer content. Note 2 : A ZSTD_CDict can be created from an empty @dictBuffer, in which case the only thing that it transports is the @compressionLevel. This can be useful in a pipeline featuring ZSTD_compress_usingCDict() exclusively, expecting a ZSTD_CDict parameter with any data, including those without a known dictionary.