cmd/bpa-operator/vendor/github.com/emicklei/go-restful/compressor_pools.go

   1 package restful
   2
   3 // Copyright 2015 Ernest Micklei. All rights reserved.
   4 // Use of this source code is governed by a license
   5 // that can be found in the LICENSE file.
   6
   7 import (
   8         "bytes"
   9         "compress/gzip"
  10         "compress/zlib"
  11         "sync"
  12 )
  13
  14 // SyncPoolCompessors is a CompressorProvider that use the standard sync.Pool.
  15 type SyncPoolCompessors struct {
  16         GzipWriterPool *sync.Pool
  17         GzipReaderPool *sync.Pool
  18         ZlibWriterPool *sync.Pool
  19 }
  20
  21 // NewSyncPoolCompessors returns a new ("empty") SyncPoolCompessors.
  22 func NewSyncPoolCompessors() *SyncPoolCompessors {
  23         return &SyncPoolCompessors{
  24                 GzipWriterPool: &sync.Pool{
  25                         New: func() interface{} { return newGzipWriter() },
  26                 },
  27                 GzipReaderPool: &sync.Pool{
  28                         New: func() interface{} { return newGzipReader() },
  29                 },
  30                 ZlibWriterPool: &sync.Pool{
  31                         New: func() interface{} { return newZlibWriter() },
  32                 },
  33         }
  34 }
  35
  36 func (s *SyncPoolCompessors) AcquireGzipWriter() *gzip.Writer {
  37         return s.GzipWriterPool.Get().(*gzip.Writer)
  38 }
  39
  40 func (s *SyncPoolCompessors) ReleaseGzipWriter(w *gzip.Writer) {
  41         s.GzipWriterPool.Put(w)
  42 }
  43
  44 func (s *SyncPoolCompessors) AcquireGzipReader() *gzip.Reader {
  45         return s.GzipReaderPool.Get().(*gzip.Reader)
  46 }
  47
  48 func (s *SyncPoolCompessors) ReleaseGzipReader(r *gzip.Reader) {
  49         s.GzipReaderPool.Put(r)
  50 }
  51
  52 func (s *SyncPoolCompessors) AcquireZlibWriter() *zlib.Writer {
  53         return s.ZlibWriterPool.Get().(*zlib.Writer)
  54 }
  55
  56 func (s *SyncPoolCompessors) ReleaseZlibWriter(w *zlib.Writer) {
  57         s.ZlibWriterPool.Put(w)
  58 }
  59
  60 func newGzipWriter() *gzip.Writer {
  61         // create with an empty bytes writer; it will be replaced before using the gzipWriter
  62         writer, err := gzip.NewWriterLevel(new(bytes.Buffer), gzip.BestSpeed)
  63         if err != nil {
  64                 panic(err.Error())
  65         }
  66         return writer
  67 }
  68
  69 func newGzipReader() *gzip.Reader {
  70         // create with an empty reader (but with GZIP header); it will be replaced before using the gzipReader
  71         // we can safely use currentCompressProvider because it is set on package initialization.
  72         w := currentCompressorProvider.AcquireGzipWriter()
  73         defer currentCompressorProvider.ReleaseGzipWriter(w)
  74         b := new(bytes.Buffer)
  75         w.Reset(b)
  76         w.Flush()
  77         w.Close()
  78         reader, err := gzip.NewReader(bytes.NewReader(b.Bytes()))
  79         if err != nil {
  80                 panic(err.Error())
  81         }
  82         return reader
  83 }
  84
  85 func newZlibWriter() *zlib.Writer {
  86         writer, err := zlib.NewWriterLevel(new(bytes.Buffer), gzip.BestSpeed)
  87         if err != nil {
  88                 panic(err.Error())
  89         }
  90         return writer
  91 }