benchmarks for write with compression enabled/disabled

[FZambia]

This is to help in investigating #203

Output on my machine:

BenchmarkWriteNoCompression-4 3000000 503 ns/op 48 B/op 1 allocs/op BenchmarkWriteWithCompression-4 30000 41481 ns/op 123 B/op 3 allocs/op 

Investingating only BenchmarkWriteWithCompression, here is cpu profile output:

(pprof) top 10 --cum 1.14s of 1.55s total (73.55%) Showing top 10 nodes out of 67 (cum >= 0.95s) flat flat% sum% cum cum% 0 0% 0% 1.54s 99.35% github.com/FZambia/websocket.(*Conn).WriteMessage 0 0% 0% 1.54s 99.35% github.com/FZambia/websocket.BenchmarkWriteWithCompression 0 0% 0% 1.54s 99.35% runtime.goexit 0 0% 0% 1.54s 99.35% testing.(*B).launch 0 0% 0% 1.54s 99.35% testing.(*B).runN 0.02s 1.29% 1.29% 1.21s 78.06% github.com/FZambia/websocket.(*Conn).NextWriter 1.08s 69.68% 70.97% 1.08s 69.68% runtime.memclr 0.03s 1.94% 72.90% 1.03s 66.45% github.com/FZambia/websocket.compressNoContextTakeover 0 0% 72.90% 0.95s 61.29% compress/flate.(*Writer).Reset 0.01s 0.65% 73.55% 0.95s 61.29% compress/flate.(*compressor).reset (pprof) list NextWriter Total: 1.55s ROUTINE ======================== github.com/FZambia/websocket.(*Conn).NextWriter in /Users/a.emelin/work/gopath/src/github.com/FZambia/websocket/conn.go 20ms 1.21s (flat, cum) 78.06% of Total . . 444: } . . 445: . . 446: mw := &messageWriter{ . . 447: c: c, . . 448: frameType: messageType, 20ms 180ms 449: pos: maxFrameHeaderSize, . . 450: } . . 451: c.writer = mw . . 452: if c.newCompressionWriter != nil && c.enableWriteCompression && isData(messageType) { . 1.03s 453: w := c.newCompressionWriter(c.writer) . . 454: mw.compress = true . . 455: c.writer = w . . 456: } . . 457: return c.writer, nil . . 458:} (pprof) list compressNoContextTakeover Total: 1.55s ROUTINE ======================== github.com/FZambia/websocket.compressNoContextTakeover in /Users/a.emelin/work/gopath/src/github.com/FZambia/websocket/compression.go 30ms 1.03s (flat, cum) 66.45% of Total . . 33: fr.(flate.Resetter).Reset(io.MultiReader(r, strings.NewReader(tail)), nil) . . 34: return &flateReadWrapper{fr} . . 35:} . . 36: . . 37:func compressNoContextTakeover(w io.WriteCloser) io.WriteCloser { 10ms 40ms 38: tw := &truncWriter{w: w} . 10ms 39: fw, _ := flateWriterPool.Get().(*flate.Writer) . 950ms 40: fw.Reset(tw) 20ms 30ms 41: return &flateWriteWrapper{fw: fw, tw: tw} . . 42:} . . 43: . . 44:// truncWriter is an io.Writer that writes all but the last four bytes of the . . 45:// stream to another io.Writer. . . 46:type truncWriter struct { 

Heap:

$ go tool pprof --alloc_space websocket.test mem Entering interactive mode (type "help" for commands) (pprof) top 10 --cum 6.53MB of 8.64MB total (75.52%) Showing top 10 nodes out of 23 (cum >= 5.13MB) flat flat% sum% cum cum% 0 0% 0% 8.64MB 100% runtime.goexit 1.50MB 17.36% 17.36% 8.13MB 94.03% github.com/FZambia/websocket.(*Conn).NextWriter 0 0% 17.36% 8.13MB 94.03% github.com/FZambia/websocket.(*Conn).WriteMessage 0 0% 17.36% 8.13MB 94.03% github.com/FZambia/websocket.BenchmarkWriteWithCompression 0 0% 17.36% 8.13MB 94.03% testing.(*B).runN 0 0% 17.36% 7.24MB 83.83% testing.(*B).launch 1.50MB 17.36% 34.72% 6.63MB 76.67% github.com/FZambia/websocket.compressNoContextTakeover 3.53MB 40.80% 75.52% 5.13MB 59.31% compress/flate.NewWriter 0 0% 75.52% 5.13MB 59.31% github.com/FZambia/websocket.glob..func1 0 0% 75.52% 5.13MB 59.31% sync.(*Pool).Get (pprof) list NextWriter Total: 8.64MB ROUTINE ======================== github.com/FZambia/websocket.(*Conn).NextWriter in /Users/a.emelin/work/gopath/src/github.com/FZambia/websocket/conn.go 1.50MB 8.13MB (flat, cum) 94.03% of Total . . 444: } . . 445: . . 446: mw := &messageWriter{ . . 447: c: c, . . 448: frameType: messageType, 1.50MB 1.50MB 449: pos: maxFrameHeaderSize, . . 450: } . . 451: c.writer = mw . . 452: if c.newCompressionWriter != nil && c.enableWriteCompression && isData(messageType) { . 6.63MB 453: w := c.newCompressionWriter(c.writer) . . 454: mw.compress = true . . 455: c.writer = w . . 456: } . . 457: return c.writer, nil . . 458:} (pprof) list compressNoContextTakeover Total: 8.64MB ROUTINE ======================== github.com/FZambia/websocket.compressNoContextTakeover in /Users/a.emelin/work/gopath/src/github.com/FZambia/websocket/compression.go 1.50MB 6.63MB (flat, cum) 76.67% of Total . . 33: fr.(flate.Resetter).Reset(io.MultiReader(r, strings.NewReader(tail)), nil) . . 34: return &flateReadWrapper{fr} . . 35:} . . 36: . . 37:func compressNoContextTakeover(w io.WriteCloser) io.WriteCloser { 512.02kB 512.02kB 38: tw := &truncWriter{w: w} . 5.13MB 39: fw, _ := flateWriterPool.Get().(*flate.Writer) . . 40: fw.Reset(tw) 1MB 1MB 41: return &flateWriteWrapper{fw: fw, tw: tw} . . 42:} . . 43: . . 44:// truncWriter is an io.Writer that writes all but the last four bytes of the . . 45:// stream to another io.Writer. . . 46:type truncWriter struct {