From 94771a177ba133bfadd0ffba55d82e7e3989ea06 Mon Sep 17 00:00:00 2001 From: Nicholas Nethercote Date: Thu, 20 Oct 2016 13:53:27 +1100 Subject: [PATCH] Use fast decompression in `deflate_bytes`. This commit changes the parameters of `deflate` to do faster, lower-quality compression. For the compression of LLVM bytecode -- which is the main use of `deflate_bytes` -- it makes compression almost twice as fast while the size of the compressed files is only ~2% worse. --- src/libflate/lib.rs | 9 ++++++--- 1 file changed, 6 insertions(+), 3 deletions(-) diff --git a/src/libflate/lib.rs b/src/libflate/lib.rs index 89df931da029..3c608ef9c926 100644 --- a/src/libflate/lib.rs +++ b/src/libflate/lib.rs @@ -94,11 +94,14 @@ extern "C" { -> *mut c_void; } -const LZ_NORM: c_int = 0x80; // LZ with 128 probes, "normal" +const LZ_FAST: c_int = 0x01; // LZ with 1 probe, "fast" +const TDEFL_GREEDY_PARSING_FLAG: c_int = 0x04000; // fast greedy parsing instead of lazy parsing -/// Compress a buffer without writing any sort of header on the output. +/// Compress a buffer without writing any sort of header on the output. Fast +/// compression is used because it is almost twice as fast as default +/// compression and the compression ratio is only marginally worse. pub fn deflate_bytes(bytes: &[u8]) -> Bytes { - let flags = LZ_NORM; + let flags = LZ_FAST | TDEFL_GREEDY_PARSING_FLAG; unsafe { let mut outsz: size_t = 0; let res = tdefl_compress_mem_to_heap(bytes.as_ptr() as *const _,