Have lib/raczlib use lib/cgozlib
As the cmd/ractool comment changes say, this is almost a 2x speed-up for
RAC+Zlib decoding on the enwik8 test file, comparable to the cgozlib
benchmark numbers:
$ go test -test.bench=. github.com/google/wuffs/lib/cgozlib
goos: linux
goarch: amd64
pkg: github.com/google/wuffs/lib/cgozlib
BenchmarkCgo-56 2514 477230 ns/op
BenchmarkPure-56 1090 1080853 ns/op
diff --git a/cmd/ractool/data.go b/cmd/ractool/data.go
index 5cfedb6..bf2eb76 100644
--- a/cmd/ractool/data.go
+++ b/cmd/ractool/data.go
@@ -156,9 +156,9 @@
sys 0m0.118s
$ time ractool -decode -drange=50000000..50000008 shared.rac
Business
- real 0m0.003s
- user 0m0.004s
- sys 0m0.000s
+ real 0m0.006s
+ user 0m0.003s
+ sys 0m0.003s
$ # A RAC file's chunks can be decoded in parallel, unlike ZIP,
$ # substantially reducing the real (wall clock) time taken even
@@ -168,12 +168,12 @@
user 0m0.713s
sys 0m0.025s
$ time ractool -decode -singlethreaded shared.rac > /dev/null
- real 0m0.959s
- user 0m0.920s
- sys 0m0.044s
+ real 0m0.523s
+ user 0m0.508s
+ sys 0m0.028s
$ time ractool -decode shared.rac > /dev/null
- real 0m0.095s
- user 0m1.316s
- sys 0m0.069s
+ real 0m0.052s
+ user 0m0.657s
+ sys 0m0.049s
--------
`
diff --git a/cmd/ractool/main.go b/cmd/ractool/main.go
index 0c33780..b5daf0d 100644
--- a/cmd/ractool/main.go
+++ b/cmd/ractool/main.go
@@ -157,9 +157,9 @@
sys 0m0.118s
$ time ractool -decode -drange=50000000..50000008 shared.rac
Business
- real 0m0.003s
- user 0m0.004s
- sys 0m0.000s
+ real 0m0.006s
+ user 0m0.003s
+ sys 0m0.003s
$ # A RAC file's chunks can be decoded in parallel, unlike ZIP,
$ # substantially reducing the real (wall clock) time taken even
@@ -169,13 +169,13 @@
user 0m0.713s
sys 0m0.025s
$ time ractool -decode -singlethreaded shared.rac > /dev/null
- real 0m0.959s
- user 0m0.920s
- sys 0m0.044s
+ real 0m0.523s
+ user 0m0.508s
+ sys 0m0.028s
$ time ractool -decode shared.rac > /dev/null
- real 0m0.095s
- user 0m1.316s
- sys 0m0.069s
+ real 0m0.052s
+ user 0m0.657s
+ sys 0m0.049s
--------
*/
package main
diff --git a/lib/raczlib/make_cgo.go b/lib/raczlib/make_cgo.go
new file mode 100644
index 0000000..0b56888
--- /dev/null
+++ b/lib/raczlib/make_cgo.go
@@ -0,0 +1,33 @@
+// Copyright 2019 The Wuffs Authors.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+// https://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package raczlib
+
+import (
+ "io"
+
+ "github.com/google/wuffs/lib/cgozlib"
+ "github.com/google/wuffs/lib/rac"
+)
+
+// MakeDecompressor implements rac.CodecReader.
+func (r *CodecReader) MakeDecompressor(compressed io.Reader, rctx rac.ReaderContext) (io.Reader, error) {
+ if r.cachedZlibReader == nil {
+ r.cachedZlibReader = &cgozlib.Reader{}
+ }
+ if err := r.cachedZlibReader.Reset(compressed, rctx.Secondary); err != nil {
+ return nil, err
+ }
+ return r.cachedZlibReader, nil
+}
diff --git a/lib/raczlib/make_notcgo.go b/lib/raczlib/make_notcgo.go
new file mode 100644
index 0000000..cdfddac
--- /dev/null
+++ b/lib/raczlib/make_notcgo.go
@@ -0,0 +1,41 @@
+// Copyright 2019 The Wuffs Authors.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+// https://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+// +build !cgo
+
+package raczlib
+
+import (
+ "compress/zlib"
+ "io"
+
+ "github.com/google/wuffs/lib/rac"
+)
+
+// MakeDecompressor implements rac.CodecReader.
+func (r *CodecReader) MakeDecompressor(compressed io.Reader, rctx rac.ReaderContext) (io.Reader, error) {
+ if r.cachedZlibReader != nil {
+ if err := r.cachedZlibReader.Reset(compressed, rctx.Secondary); err != nil {
+ return nil, err
+ }
+ return r.cachedZlibReader, nil
+ }
+
+ zlibReader, err := zlib.NewReaderDict(compressed, rctx.Secondary)
+ if err != nil {
+ return nil, err
+ }
+ r.cachedZlibReader = zlibReader.(resetReadCloser)
+ return zlibReader, nil
+}
diff --git a/lib/raczlib/raczlib.go b/lib/raczlib/raczlib.go
index a47874f..0e0e24e 100644
--- a/lib/raczlib/raczlib.go
+++ b/lib/raczlib/raczlib.go
@@ -54,11 +54,22 @@
return b
}
+type resetReadCloser interface {
+ // Reset is the zlib.Resetter interface's sole method.
+ //
+ // We explicitly spell out the method signature, instead of just saying
+ // "zlib.Resetter". It may be possible for a future version of this package
+ // to not depend on the standard library's "compress/zlib" package at all.
+ Reset(r io.Reader, dict []byte) error
+
+ io.ReadCloser
+}
+
// CodecReader specializes a rac.Reader to decode Zlib-compressed chunks.
type CodecReader struct {
// cachedZlibReader lets us re-use the memory allocated for a zlib reader,
// when decompressing multiple chunks.
- cachedZlibReader zlib.Resetter
+ cachedZlibReader resetReadCloser
// These fields contain the most recently used shared dictionary.
cachedDictionary []byte
@@ -78,25 +89,6 @@
return &CodecReader{}
}
-// MakeDecompressor implements rac.CodecReader.
-func (r *CodecReader) MakeDecompressor(
- compressed io.Reader, rctx rac.ReaderContext) (io.Reader, error) {
-
- if r.cachedZlibReader != nil {
- if err := r.cachedZlibReader.Reset(compressed, rctx.Secondary); err != nil {
- return nil, err
- }
- return r.cachedZlibReader.(io.Reader), nil
- }
-
- zlibReader, err := zlib.NewReaderDict(compressed, rctx.Secondary)
- if err != nil {
- return nil, err
- }
- r.cachedZlibReader = zlibReader.(zlib.Resetter)
- return zlibReader, nil
-}
-
// MakeReaderContext implements rac.CodecReader.
func (r *CodecReader) MakeReaderContext(rs io.ReadSeeker, chunk rac.Chunk) (rac.ReaderContext, error) {
// For a description of the RAC+Zlib secondary-data format, see
