From 9d6dce119949d340ebb42becae018a3c11148690 Mon Sep 17 00:00:00 2001 From: Daniel J Walsh Date: Thu, 1 Aug 2019 03:46:14 -0400 Subject: github.com/containers/storage v1.12.13 Signed-off-by: Daniel J Walsh --- vendor/github.com/DataDog/zstd/zstd.go | 147 --------------------------------- 1 file changed, 147 deletions(-) delete mode 100644 vendor/github.com/DataDog/zstd/zstd.go (limited to 'vendor/github.com/DataDog/zstd/zstd.go') diff --git a/vendor/github.com/DataDog/zstd/zstd.go b/vendor/github.com/DataDog/zstd/zstd.go deleted file mode 100644 index b6af4eb19..000000000 --- a/vendor/github.com/DataDog/zstd/zstd.go +++ /dev/null @@ -1,147 +0,0 @@ -package zstd - -/* -#define ZSTD_STATIC_LINKING_ONLY -#include "zstd.h" -#include "stdint.h" // for uintptr_t - -// The following *_wrapper function are used for removing superflouos -// memory allocations when calling the wrapped functions from Go code. -// See https://github.com/golang/go/issues/24450 for details. - -static size_t ZSTD_compress_wrapper(uintptr_t dst, size_t maxDstSize, const uintptr_t src, size_t srcSize, int compressionLevel) { - return ZSTD_compress((void*)dst, maxDstSize, (const void*)src, srcSize, compressionLevel); -} - -static size_t ZSTD_decompress_wrapper(uintptr_t dst, size_t maxDstSize, uintptr_t src, size_t srcSize) { - return ZSTD_decompress((void*)dst, maxDstSize, (const void *)src, srcSize); -} - -*/ -import "C" -import ( - "bytes" - "errors" - "io/ioutil" - "runtime" - "unsafe" -) - -// Defines best and standard values for zstd cli -const ( - BestSpeed = 1 - BestCompression = 20 - DefaultCompression = 5 -) - -var ( - // ErrEmptySlice is returned when there is nothing to compress - ErrEmptySlice = errors.New("Bytes slice is empty") -) - -// CompressBound returns the worst case size needed for a destination buffer, -// which can be used to preallocate a destination buffer or select a previously -// allocated buffer from a pool. -// See zstd.h to mirror implementation of ZSTD_COMPRESSBOUND -func CompressBound(srcSize int) int { - lowLimit := 128 << 10 // 128 kB - var margin int - if srcSize < lowLimit { - margin = (lowLimit - srcSize) >> 11 - } - return srcSize + (srcSize >> 8) + margin -} - -// cCompressBound is a cgo call to check the go implementation above against the c code. -func cCompressBound(srcSize int) int { - return int(C.ZSTD_compressBound(C.size_t(srcSize))) -} - -// Compress src into dst. If you have a buffer to use, you can pass it to -// prevent allocation. If it is too small, or if nil is passed, a new buffer -// will be allocated and returned. -func Compress(dst, src []byte) ([]byte, error) { - return CompressLevel(dst, src, DefaultCompression) -} - -// CompressLevel is the same as Compress but you can pass a compression level -func CompressLevel(dst, src []byte, level int) ([]byte, error) { - bound := CompressBound(len(src)) - if cap(dst) >= bound { - dst = dst[0:bound] // Reuse dst buffer - } else { - dst = make([]byte, bound) - } - - srcPtr := C.uintptr_t(uintptr(0)) // Do not point anywhere, if src is empty - if len(src) > 0 { - srcPtr = C.uintptr_t(uintptr(unsafe.Pointer(&src[0]))) - } - - cWritten := C.ZSTD_compress_wrapper( - C.uintptr_t(uintptr(unsafe.Pointer(&dst[0]))), - C.size_t(len(dst)), - srcPtr, - C.size_t(len(src)), - C.int(level)) - - runtime.KeepAlive(src) - written := int(cWritten) - // Check if the return is an Error code - if err := getError(written); err != nil { - return nil, err - } - return dst[:written], nil -} - -// Decompress src into dst. If you have a buffer to use, you can pass it to -// prevent allocation. If it is too small, or if nil is passed, a new buffer -// will be allocated and returned. -func Decompress(dst, src []byte) ([]byte, error) { - if len(src) == 0 { - return []byte{}, ErrEmptySlice - } - decompress := func(dst, src []byte) ([]byte, error) { - - cWritten := C.ZSTD_decompress_wrapper( - C.uintptr_t(uintptr(unsafe.Pointer(&dst[0]))), - C.size_t(len(dst)), - C.uintptr_t(uintptr(unsafe.Pointer(&src[0]))), - C.size_t(len(src))) - - runtime.KeepAlive(src) - written := int(cWritten) - // Check error - if err := getError(written); err != nil { - return nil, err - } - return dst[:written], nil - } - - if len(dst) == 0 { - // Attempt to use zStd to determine decompressed size (may result in error or 0) - size := int(C.size_t(C.ZSTD_getDecompressedSize(unsafe.Pointer(&src[0]), C.size_t(len(src))))) - - if err := getError(size); err != nil { - return nil, err - } - - if size > 0 { - dst = make([]byte, size) - } else { - dst = make([]byte, len(src)*3) // starting guess - } - } - for i := 0; i < 3; i++ { // 3 tries to allocate a bigger buffer - result, err := decompress(dst, src) - if !IsDstSizeTooSmallError(err) { - return result, err - } - dst = make([]byte, len(dst)*2) // Grow buffer by 2 - } - - // We failed getting a dst buffer of correct size, use stream API - r := NewReader(bytes.NewReader(src)) - defer r.Close() - return ioutil.ReadAll(r) -} -- cgit v1.2.3-54-g00ecf