From 2f0b35e3c25bc4394f3288e1baa77d250cb510ed Mon Sep 17 00:00:00 2001 From: Jordan Date: Thu, 10 Feb 2022 19:10:54 -0700 Subject: misc: go mod vendor --- vendor/github.com/gorilla/websocket/compression.go | 148 +++++++++++++++++++++ 1 file changed, 148 insertions(+) create mode 100644 vendor/github.com/gorilla/websocket/compression.go (limited to 'vendor/github.com/gorilla/websocket/compression.go') diff --git a/vendor/github.com/gorilla/websocket/compression.go b/vendor/github.com/gorilla/websocket/compression.go new file mode 100644 index 0000000..813ffb1 --- /dev/null +++ b/vendor/github.com/gorilla/websocket/compression.go @@ -0,0 +1,148 @@ +// Copyright 2017 The Gorilla WebSocket Authors. All rights reserved. +// Use of this source code is governed by a BSD-style +// license that can be found in the LICENSE file. + +package websocket + +import ( + "compress/flate" + "errors" + "io" + "strings" + "sync" +) + +const ( + minCompressionLevel = -2 // flate.HuffmanOnly not defined in Go < 1.6 + maxCompressionLevel = flate.BestCompression + defaultCompressionLevel = 1 +) + +var ( + flateWriterPools [maxCompressionLevel - minCompressionLevel + 1]sync.Pool + flateReaderPool = sync.Pool{New: func() interface{} { + return flate.NewReader(nil) + }} +) + +func decompressNoContextTakeover(r io.Reader) io.ReadCloser { + const tail = + // Add four bytes as specified in RFC + "\x00\x00\xff\xff" + + // Add final block to squelch unexpected EOF error from flate reader. + "\x01\x00\x00\xff\xff" + + fr, _ := flateReaderPool.Get().(io.ReadCloser) + fr.(flate.Resetter).Reset(io.MultiReader(r, strings.NewReader(tail)), nil) + return &flateReadWrapper{fr} +} + +func isValidCompressionLevel(level int) bool { + return minCompressionLevel <= level && level <= maxCompressionLevel +} + +func compressNoContextTakeover(w io.WriteCloser, level int) io.WriteCloser { + p := &flateWriterPools[level-minCompressionLevel] + tw := &truncWriter{w: w} + fw, _ := p.Get().(*flate.Writer) + if fw == nil { + fw, _ = flate.NewWriter(tw, level) + } else { + fw.Reset(tw) + } + return &flateWriteWrapper{fw: fw, tw: tw, p: p} +} + +// truncWriter is an io.Writer that writes all but the last four bytes of the +// stream to another io.Writer. +type truncWriter struct { + w io.WriteCloser + n int + p [4]byte +} + +func (w *truncWriter) Write(p []byte) (int, error) { + n := 0 + + // fill buffer first for simplicity. + if w.n < len(w.p) { + n = copy(w.p[w.n:], p) + p = p[n:] + w.n += n + if len(p) == 0 { + return n, nil + } + } + + m := len(p) + if m > len(w.p) { + m = len(w.p) + } + + if nn, err := w.w.Write(w.p[:m]); err != nil { + return n + nn, err + } + + copy(w.p[:], w.p[m:]) + copy(w.p[len(w.p)-m:], p[len(p)-m:]) + nn, err := w.w.Write(p[:len(p)-m]) + return n + nn, err +} + +type flateWriteWrapper struct { + fw *flate.Writer + tw *truncWriter + p *sync.Pool +} + +func (w *flateWriteWrapper) Write(p []byte) (int, error) { + if w.fw == nil { + return 0, errWriteClosed + } + return w.fw.Write(p) +} + +func (w *flateWriteWrapper) Close() error { + if w.fw == nil { + return errWriteClosed + } + err1 := w.fw.Flush() + w.p.Put(w.fw) + w.fw = nil + if w.tw.p != [4]byte{0, 0, 0xff, 0xff} { + return errors.New("websocket: internal error, unexpected bytes at end of flate stream") + } + err2 := w.tw.w.Close() + if err1 != nil { + return err1 + } + return err2 +} + +type flateReadWrapper struct { + fr io.ReadCloser +} + +func (r *flateReadWrapper) Read(p []byte) (int, error) { + if r.fr == nil { + return 0, io.ErrClosedPipe + } + n, err := r.fr.Read(p) + if err == io.EOF { + // Preemptively place the reader back in the pool. This helps with + // scenarios where the application does not call NextReader() soon after + // this final read. + r.Close() + } + return n, err +} + +func (r *flateReadWrapper) Close() error { + if r.fr == nil { + return io.ErrClosedPipe + } + err := r.fr.Close() + flateReaderPool.Put(r.fr) + r.fr = nil + return err +} -- cgit v1.2.3-54-g00ecf