1 // Copyright 2011 The Snappy-Go Authors. All rights reserved. 2 // Use of this source code is governed by a BSD-style 3 // license that can be found in the LICENSE file. 4 5 package snappy 6 7 import ( 8 "io" 9 10 "github.com/klauspost/compress/s2" 11 ) 12 13 var ( 14 // ErrCorrupt reports that the input is invalid. 15 ErrCorrupt = s2.ErrCorrupt 16 // ErrTooLarge reports that the uncompressed length is too large. 17 ErrTooLarge = s2.ErrTooLarge 18 // ErrUnsupported reports that the input isn't supported. 19 ErrUnsupported = s2.ErrUnsupported 20 ) 21 22 const ( 23 // maxBlockSize is the maximum size of the input to encodeBlock. It is not 24 // part of the wire format per se, but some parts of the encoder assume 25 // that an offset fits into a uint16. 26 // 27 // Also, for the framing format (Writer type instead of Encode function), 28 // https://github.com/google/snappy/blob/master/framing_format.txt says 29 // that "the uncompressed data in a chunk must be no longer than 65536 30 // bytes". 31 maxBlockSize = 65536 32 ) 33 34 // DecodedLen returns the length of the decoded block. 35 func DecodedLen(src []byte) (int, error) { 36 return s2.DecodedLen(src) 37 } 38 39 // Decode returns the decoded form of src. The returned slice may be a sub- 40 // slice of dst if dst was large enough to hold the entire decoded block. 41 // Otherwise, a newly allocated slice will be returned. 42 // 43 // The dst and src must not overlap. It is valid to pass a nil dst. 44 // 45 // Decode handles the Snappy block format, not the Snappy stream format. 46 func Decode(dst, src []byte) ([]byte, error) { 47 return s2.Decode(dst, src) 48 } 49 50 // NewReader returns a new Reader that decompresses from r, using the framing 51 // format described at 52 // https://github.com/google/snappy/blob/master/framing_format.txt 53 func NewReader(r io.Reader) *Reader { 54 return s2.NewReader(r, s2.ReaderMaxBlockSize(maxBlockSize)) 55 } 56 57 // Reader is an io.Reader that can read Snappy-compressed bytes. 58 // 59 // Reader handles the Snappy stream format, not the Snappy block format. 60 type Reader = s2.Reader 61