Zstandardzstd, short for Zstandard, is a fast lossless compression algorithm, targeting real-time compression scenarios at zlib-level and better compression ratios. The zstd compression library provides in-memory compression and decompression functions. The library supports compression levels from 1 up to max_compression_level () (currently 22). Levels >= 20, labeled `--ultra`, should be used with caution, as they require more memory.
Compression can be done in:
The compression ratio achievable on small data can be highly improved using a dictionary in:
Also see LZ4.
exception Decompressed_size_exceeds_max_int of Core_kernel.Int64.tmodule Output : sig ... endmodule Input : sig ... endval decompressed_size : Input.t -> Core_kernel.Int64.tReturns the decompressed size of a message. Since decompressed size is an optional field of compressed message, it might raise Content_size_unknown, Content_size_error or Error.
module Compression_context : sig ... endmodule Decompression_context : sig ... endmodule Simple : sig ... endmodule With_explicit_context : sig ... endThis module implements compression and decompression with explicitly managed contexts. When compressing or decompressing many times, it is recommended to allocate a context just once, and re-use it for each successive compression operation. This will make workload friendlier for system's memory.
module Dictionary : sig ... endmodule Simple_dictionary : sig ... endmodule Bulk_processing_dictionary : sig ... endmodule Streaming : sig ... endThe functions exposed in this module differ from the rest of the library, and operates on stream of data (rather than on single messages). Therefore, the API is more complex, and does not use the Input module.