diff options
Diffstat (limited to 'test/bench/go1/revcomp_test.go')
-rw-r--r-- | test/bench/go1/revcomp_test.go | 85 |
1 files changed, 85 insertions, 0 deletions
diff --git a/test/bench/go1/revcomp_test.go b/test/bench/go1/revcomp_test.go new file mode 100644 index 0000000..c2e2c39 --- /dev/null +++ b/test/bench/go1/revcomp_test.go @@ -0,0 +1,85 @@ +// Copyright 2011 The Go Authors. All rights reserved. +// Use of this source code is governed by a BSD-style +// license that can be found in the LICENSE file. + +// This benchmark, taken from the shootout, tests array indexing +// and array bounds elimination performance. + +package go1 + +import ( + "bufio" + "bytes" + "io" + "testing" +) + +var revCompTable = [256]uint8{ + 'A': 'T', 'a': 'T', + 'C': 'G', 'c': 'G', + 'G': 'C', 'g': 'C', + 'T': 'A', 't': 'A', + 'U': 'A', 'u': 'A', + 'M': 'K', 'm': 'K', + 'R': 'Y', 'r': 'Y', + 'W': 'W', 'w': 'W', + 'S': 'S', 's': 'S', + 'Y': 'R', 'y': 'R', + 'K': 'M', 'k': 'M', + 'V': 'B', 'v': 'B', + 'H': 'D', 'h': 'D', + 'D': 'H', 'd': 'H', + 'B': 'V', 'b': 'V', + 'N': 'N', 'n': 'N', +} + +func revcomp(data []byte) { + in := bufio.NewReader(bytes.NewBuffer(data)) + out := io.Discard + buf := make([]byte, 1024*1024) + line, err := in.ReadSlice('\n') + for err == nil { + out.Write(line) + + // Accumulate reversed complement in buf[w:] + nchar := 0 + w := len(buf) + for { + line, err = in.ReadSlice('\n') + if err != nil || line[0] == '>' { + break + } + line = line[0 : len(line)-1] + nchar += len(line) + if len(line)+nchar/60+128 >= w { + nbuf := make([]byte, len(buf)*5) + copy(nbuf[len(nbuf)-len(buf):], buf) + w += len(nbuf) - len(buf) + buf = nbuf + } + + // This loop is the bottleneck. + for _, c := range line { + w-- + buf[w] = revCompTable[c] + } + } + + // Copy down to beginning of buffer, inserting newlines. + // The loop left room for the newlines and 128 bytes of padding. + i := 0 + for j := w; j < len(buf); j += 60 { + n := copy(buf[i:i+60], buf[j:]) + buf[i+n] = '\n' + i += n + 1 + } + out.Write(buf[0:i]) + } +} + +func BenchmarkRevcomp(b *testing.B) { + b.SetBytes(int64(len(fastabytes))) + for i := 0; i < b.N; i++ { + revcomp(fastabytes) + } +} |