diff options
Diffstat (limited to 'vendor/github.com/klauspost/compress/zstd/snappy.go')
| -rw-r--r-- | vendor/github.com/klauspost/compress/zstd/snappy.go | 434 |
1 files changed, 0 insertions, 434 deletions
diff --git a/vendor/github.com/klauspost/compress/zstd/snappy.go b/vendor/github.com/klauspost/compress/zstd/snappy.go deleted file mode 100644 index ec13594e8..000000000 --- a/vendor/github.com/klauspost/compress/zstd/snappy.go +++ /dev/null @@ -1,434 +0,0 @@ -// Copyright 2019+ Klaus Post. All rights reserved. -// License information can be found in the LICENSE file. -// Based on work by Yann Collet, released under BSD License. - -package zstd - -import ( - "encoding/binary" - "errors" - "hash/crc32" - "io" - - "github.com/klauspost/compress/huff0" - snappy "github.com/klauspost/compress/internal/snapref" -) - -const ( - snappyTagLiteral = 0x00 - snappyTagCopy1 = 0x01 - snappyTagCopy2 = 0x02 - snappyTagCopy4 = 0x03 -) - -const ( - snappyChecksumSize = 4 - snappyMagicBody = "sNaPpY" - - // snappyMaxBlockSize is the maximum size of the input to encodeBlock. It is not - // part of the wire format per se, but some parts of the encoder assume - // that an offset fits into a uint16. - // - // Also, for the framing format (Writer type instead of Encode function), - // https://github.com/google/snappy/blob/master/framing_format.txt says - // that "the uncompressed data in a chunk must be no longer than 65536 - // bytes". - snappyMaxBlockSize = 65536 - - // snappyMaxEncodedLenOfMaxBlockSize equals MaxEncodedLen(snappyMaxBlockSize), but is - // hard coded to be a const instead of a variable, so that obufLen can also - // be a const. Their equivalence is confirmed by - // TestMaxEncodedLenOfMaxBlockSize. - snappyMaxEncodedLenOfMaxBlockSize = 76490 -) - -const ( - chunkTypeCompressedData = 0x00 - chunkTypeUncompressedData = 0x01 - chunkTypePadding = 0xfe - chunkTypeStreamIdentifier = 0xff -) - -var ( - // ErrSnappyCorrupt reports that the input is invalid. - ErrSnappyCorrupt = errors.New("snappy: corrupt input") - // ErrSnappyTooLarge reports that the uncompressed length is too large. - ErrSnappyTooLarge = errors.New("snappy: decoded block is too large") - // ErrSnappyUnsupported reports that the input isn't supported. - ErrSnappyUnsupported = errors.New("snappy: unsupported input") - - errUnsupportedLiteralLength = errors.New("snappy: unsupported literal length") -) - -// SnappyConverter can read SnappyConverter-compressed streams and convert them to zstd. -// Conversion is done by converting the stream directly from Snappy without intermediate -// full decoding. -// Therefore the compression ratio is much less than what can be done by a full decompression -// and compression, and a faulty Snappy stream may lead to a faulty Zstandard stream without -// any errors being generated. -// No CRC value is being generated and not all CRC values of the Snappy stream are checked. -// However, it provides really fast recompression of Snappy streams. -// The converter can be reused to avoid allocations, even after errors. -type SnappyConverter struct { - r io.Reader - err error - buf []byte - block *blockEnc -} - -// Convert the Snappy stream supplied in 'in' and write the zStandard stream to 'w'. -// If any error is detected on the Snappy stream it is returned. -// The number of bytes written is returned. -func (r *SnappyConverter) Convert(in io.Reader, w io.Writer) (int64, error) { - initPredefined() - r.err = nil - r.r = in - if r.block == nil { - r.block = &blockEnc{} - r.block.init() - } - r.block.initNewEncode() - if len(r.buf) != snappyMaxEncodedLenOfMaxBlockSize+snappyChecksumSize { - r.buf = make([]byte, snappyMaxEncodedLenOfMaxBlockSize+snappyChecksumSize) - } - r.block.litEnc.Reuse = huff0.ReusePolicyNone - var written int64 - var readHeader bool - { - header := frameHeader{WindowSize: snappyMaxBlockSize}.appendTo(r.buf[:0]) - - var n int - n, r.err = w.Write(header) - if r.err != nil { - return written, r.err - } - written += int64(n) - } - - for { - if !r.readFull(r.buf[:4], true) { - // Add empty last block - r.block.reset(nil) - r.block.last = true - err := r.block.encodeLits(r.block.literals, false) - if err != nil { - return written, err - } - n, err := w.Write(r.block.output) - if err != nil { - return written, err - } - written += int64(n) - - return written, r.err - } - chunkType := r.buf[0] - if !readHeader { - if chunkType != chunkTypeStreamIdentifier { - println("chunkType != chunkTypeStreamIdentifier", chunkType) - r.err = ErrSnappyCorrupt - return written, r.err - } - readHeader = true - } - chunkLen := int(r.buf[1]) | int(r.buf[2])<<8 | int(r.buf[3])<<16 - if chunkLen > len(r.buf) { - println("chunkLen > len(r.buf)", chunkType) - r.err = ErrSnappyUnsupported - return written, r.err - } - - // The chunk types are specified at - // https://github.com/google/snappy/blob/master/framing_format.txt - switch chunkType { - case chunkTypeCompressedData: - // Section 4.2. Compressed data (chunk type 0x00). - if chunkLen < snappyChecksumSize { - println("chunkLen < snappyChecksumSize", chunkLen, snappyChecksumSize) - r.err = ErrSnappyCorrupt - return written, r.err - } - buf := r.buf[:chunkLen] - if !r.readFull(buf, false) { - return written, r.err - } - //checksum := uint32(buf[0]) | uint32(buf[1])<<8 | uint32(buf[2])<<16 | uint32(buf[3])<<24 - buf = buf[snappyChecksumSize:] - - n, hdr, err := snappyDecodedLen(buf) - if err != nil { - r.err = err - return written, r.err - } - buf = buf[hdr:] - if n > snappyMaxBlockSize { - println("n > snappyMaxBlockSize", n, snappyMaxBlockSize) - r.err = ErrSnappyCorrupt - return written, r.err - } - r.block.reset(nil) - r.block.pushOffsets() - if err := decodeSnappy(r.block, buf); err != nil { - r.err = err - return written, r.err - } - if r.block.size+r.block.extraLits != n { - printf("invalid size, want %d, got %d\n", n, r.block.size+r.block.extraLits) - r.err = ErrSnappyCorrupt - return written, r.err - } - err = r.block.encode(nil, false, false) - switch err { - case errIncompressible: - r.block.popOffsets() - r.block.reset(nil) - r.block.literals, err = snappy.Decode(r.block.literals[:n], r.buf[snappyChecksumSize:chunkLen]) - if err != nil { - return written, err - } - err = r.block.encodeLits(r.block.literals, false) - if err != nil { - return written, err - } - case nil: - default: - return written, err - } - - n, r.err = w.Write(r.block.output) - if r.err != nil { - return written, err - } - written += int64(n) - continue - case chunkTypeUncompressedData: - if debugEncoder { - println("Uncompressed, chunklen", chunkLen) - } - // Section 4.3. Uncompressed data (chunk type 0x01). - if chunkLen < snappyChecksumSize { - println("chunkLen < snappyChecksumSize", chunkLen, snappyChecksumSize) - r.err = ErrSnappyCorrupt - return written, r.err - } - r.block.reset(nil) - buf := r.buf[:snappyChecksumSize] - if !r.readFull(buf, false) { - return written, r.err - } - checksum := uint32(buf[0]) | uint32(buf[1])<<8 | uint32(buf[2])<<16 | uint32(buf[3])<<24 - // Read directly into r.decoded instead of via r.buf. - n := chunkLen - snappyChecksumSize - if n > snappyMaxBlockSize { - println("n > snappyMaxBlockSize", n, snappyMaxBlockSize) - r.err = ErrSnappyCorrupt - return written, r.err - } - r.block.literals = r.block.literals[:n] - if !r.readFull(r.block.literals, false) { - return written, r.err - } - if snappyCRC(r.block.literals) != checksum { - println("literals crc mismatch") - r.err = ErrSnappyCorrupt - return written, r.err - } - err := r.block.encodeLits(r.block.literals, false) - if err != nil { - return written, err - } - n, r.err = w.Write(r.block.output) - if r.err != nil { - return written, err - } - written += int64(n) - continue - - case chunkTypeStreamIdentifier: - if debugEncoder { - println("stream id", chunkLen, len(snappyMagicBody)) - } - // Section 4.1. Stream identifier (chunk type 0xff). - if chunkLen != len(snappyMagicBody) { - println("chunkLen != len(snappyMagicBody)", chunkLen, len(snappyMagicBody)) - r.err = ErrSnappyCorrupt - return written, r.err - } - if !r.readFull(r.buf[:len(snappyMagicBody)], false) { - return written, r.err - } - for i := 0; i < len(snappyMagicBody); i++ { - if r.buf[i] != snappyMagicBody[i] { - println("r.buf[i] != snappyMagicBody[i]", r.buf[i], snappyMagicBody[i], i) - r.err = ErrSnappyCorrupt - return written, r.err - } - } - continue - } - - if chunkType <= 0x7f { - // Section 4.5. Reserved unskippable chunks (chunk types 0x02-0x7f). - println("chunkType <= 0x7f") - r.err = ErrSnappyUnsupported - return written, r.err - } - // Section 4.4 Padding (chunk type 0xfe). - // Section 4.6. Reserved skippable chunks (chunk types 0x80-0xfd). - if !r.readFull(r.buf[:chunkLen], false) { - return written, r.err - } - } -} - -// decodeSnappy writes the decoding of src to dst. It assumes that the varint-encoded -// length of the decompressed bytes has already been read. -func decodeSnappy(blk *blockEnc, src []byte) error { - //decodeRef(make([]byte, snappyMaxBlockSize), src) - var s, length int - lits := blk.extraLits - var offset uint32 - for s < len(src) { - switch src[s] & 0x03 { - case snappyTagLiteral: - x := uint32(src[s] >> 2) - switch { - case x < 60: - s++ - case x == 60: - s += 2 - if uint(s) > uint(len(src)) { // The uint conversions catch overflow from the previous line. - println("uint(s) > uint(len(src)", s, src) - return ErrSnappyCorrupt - } - x = uint32(src[s-1]) - case x == 61: - s += 3 - if uint(s) > uint(len(src)) { // The uint conversions catch overflow from the previous line. - println("uint(s) > uint(len(src)", s, src) - return ErrSnappyCorrupt - } - x = uint32(src[s-2]) | uint32(src[s-1])<<8 - case x == 62: - s += 4 - if uint(s) > uint(len(src)) { // The uint conversions catch overflow from the previous line. - println("uint(s) > uint(len(src)", s, src) - return ErrSnappyCorrupt - } - x = uint32(src[s-3]) | uint32(src[s-2])<<8 | uint32(src[s-1])<<16 - case x == 63: - s += 5 - if uint(s) > uint(len(src)) { // The uint conversions catch overflow from the previous line. - println("uint(s) > uint(len(src)", s, src) - return ErrSnappyCorrupt - } - x = uint32(src[s-4]) | uint32(src[s-3])<<8 | uint32(src[s-2])<<16 | uint32(src[s-1])<<24 - } - if x > snappyMaxBlockSize { - println("x > snappyMaxBlockSize", x, snappyMaxBlockSize) - return ErrSnappyCorrupt - } - length = int(x) + 1 - if length <= 0 { - println("length <= 0 ", length) - - return errUnsupportedLiteralLength - } - //if length > snappyMaxBlockSize-d || uint32(length) > len(src)-s { - // return ErrSnappyCorrupt - //} - - blk.literals = append(blk.literals, src[s:s+length]...) - //println(length, "litLen") - lits += length - s += length - continue - - case snappyTagCopy1: - s += 2 - if uint(s) > uint(len(src)) { // The uint conversions catch overflow from the previous line. - println("uint(s) > uint(len(src)", s, len(src)) - return ErrSnappyCorrupt - } - length = 4 + int(src[s-2])>>2&0x7 - offset = uint32(src[s-2])&0xe0<<3 | uint32(src[s-1]) - - case snappyTagCopy2: - s += 3 - if uint(s) > uint(len(src)) { // The uint conversions catch overflow from the previous line. - println("uint(s) > uint(len(src)", s, len(src)) - return ErrSnappyCorrupt - } - length = 1 + int(src[s-3])>>2 - offset = uint32(src[s-2]) | uint32(src[s-1])<<8 - - case snappyTagCopy4: - s += 5 - if uint(s) > uint(len(src)) { // The uint conversions catch overflow from the previous line. - println("uint(s) > uint(len(src)", s, len(src)) - return ErrSnappyCorrupt - } - length = 1 + int(src[s-5])>>2 - offset = uint32(src[s-4]) | uint32(src[s-3])<<8 | uint32(src[s-2])<<16 | uint32(src[s-1])<<24 - } - - if offset <= 0 || blk.size+lits < int(offset) /*|| length > len(blk)-d */ { - println("offset <= 0 || blk.size+lits < int(offset)", offset, blk.size+lits, int(offset), blk.size, lits) - - return ErrSnappyCorrupt - } - - // Check if offset is one of the recent offsets. - // Adjusts the output offset accordingly. - // Gives a tiny bit of compression, typically around 1%. - if false { - offset = blk.matchOffset(offset, uint32(lits)) - } else { - offset += 3 - } - - blk.sequences = append(blk.sequences, seq{ - litLen: uint32(lits), - offset: offset, - matchLen: uint32(length) - zstdMinMatch, - }) - blk.size += length + lits - lits = 0 - } - blk.extraLits = lits - return nil -} - -func (r *SnappyConverter) readFull(p []byte, allowEOF bool) (ok bool) { - if _, r.err = io.ReadFull(r.r, p); r.err != nil { - if r.err == io.ErrUnexpectedEOF || (r.err == io.EOF && !allowEOF) { - r.err = ErrSnappyCorrupt - } - return false - } - return true -} - -var crcTable = crc32.MakeTable(crc32.Castagnoli) - -// crc implements the checksum specified in section 3 of -// https://github.com/google/snappy/blob/master/framing_format.txt -func snappyCRC(b []byte) uint32 { - c := crc32.Update(0, crcTable, b) - return c>>15 | c<<17 + 0xa282ead8 -} - -// snappyDecodedLen returns the length of the decoded block and the number of bytes -// that the length header occupied. -func snappyDecodedLen(src []byte) (blockLen, headerLen int, err error) { - v, n := binary.Uvarint(src) - if n <= 0 || v > 0xffffffff { - return 0, 0, ErrSnappyCorrupt - } - - const wordSize = 32 << (^uint(0) >> 32 & 1) - if wordSize == 32 && v > 0x7fffffff { - return 0, 0, ErrSnappyTooLarge - } - return int(v), n, nil -} |