--- /dev/null
+// Copyright 2010 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.
+
+// Garbage collection benchmark: parse Go packages repeatedly.
+
+package main
+
+import (
+ "flag"
+ "fmt"
+ "go/ast"
+ "go/parser"
+ "os"
+ "path"
+ "runtime"
+ "strings"
+)
+
+func isGoFile(dir *os.Dir) bool {
+ return dir.IsRegular() &&
+ !strings.HasPrefix(dir.Name, ".") && // ignore .files
+ path.Ext(dir.Name) == ".go"
+}
+
+func isPkgFile(dir *os.Dir) bool {
+ return isGoFile(dir) &&
+ !strings.HasSuffix(dir.Name, "_test.go") // ignore test files
+}
+
+func pkgName(filename string) string {
+ file, err := parser.ParseFile(filename, nil, nil, parser.PackageClauseOnly)
+ if err != nil || file == nil {
+ return ""
+ }
+ return file.Name.Name()
+}
+
+func parseDir(dirpath string) map[string]*ast.Package {
+ // the package name is the directory name within its parent
+ // (use dirname instead of path because dirname is clean; i.e. has no trailing '/')
+ _, pkgname := path.Split(dirpath)
+
+ // filter function to select the desired .go files
+ filter := func(d *os.Dir) bool {
+ if isPkgFile(d) {
+ // Some directories contain main packages: Only accept
+ // files that belong to the expected package so that
+ // parser.ParsePackage doesn't return "multiple packages
+ // found" errors.
+ // Additionally, accept the special package name
+ // fakePkgName if we are looking at cmd documentation.
+ name := pkgName(dirpath + "/" + d.Name)
+ return name == pkgname
+ }
+ return false
+ }
+
+ // get package AST
+ pkgs, err := parser.ParseDir(dirpath, filter, parser.ParseComments)
+ if err != nil {
+ panicln("parse", dirpath, err.String())
+ }
+ return pkgs
+}
+
+func main() {
+ st := &runtime.MemStats
+ n := flag.Int("n", 10, "iterations")
+ p := flag.Int("p", len(packages), "# of packages to keep in memory")
+ flag.BoolVar(&st.DebugGC, "d", st.DebugGC, "print GC debugging info (pause times)")
+ flag.Parse()
+
+ pkgroot := os.Getenv("GOROOT") + "/src/pkg/"
+ for i := -1; i < *n; i++ {
+ parsed := make([]map[string]*ast.Package, *p)
+ for j := range parsed {
+ parsed[j] = parseDir(pkgroot + packages[j%len(packages)])
+ }
+ if i == -1 {
+ // Now that heap is grown to full size, reset counters.
+ // This hides the start-up pauses, which are much smaller
+ // than the normal pauses and would otherwise make
+ // the average look much better than it actually is.
+ st.NumGC = 0
+ st.PauseNs = 0
+ }
+ }
+
+ fmt.Printf("Alloc=%d/%d Heap=%d/%d Mallocs=%d PauseTime=%.3f/%d = %.3f\n",
+ st.Alloc, st.TotalAlloc,
+ st.InusePages<<12, st.Sys,
+ st.Mallocs, float64(st.PauseNs)/1e9,
+ st.NumGC, float64(st.PauseNs)/1e9/float64(st.NumGC))
+
+ fmt.Printf("%10s %10s %10s\n", "size", "#alloc", "#free")
+ for _, s := range st.BySize {
+ fmt.Printf("%10d %10d %10d\n", s.Size, s.Mallocs, s.Frees)
+ }
+}
+
+
+var packages = []string{
+ "archive/tar",
+ "asn1",
+ "big",
+ "bignum",
+ "bufio",
+ "bytes",
+ "compress/flate",
+ "compress/gzip",
+ "compress/zlib",
+ "container/heap",
+ "container/list",
+ "container/ring",
+ "container/vector",
+ "crypto/aes",
+ "crypto/block",
+ "crypto/hmac",
+ "crypto/md4",
+ "crypto/md5",
+ "crypto/rc4",
+ "crypto/rsa",
+ "crypto/sha1",
+ "crypto/sha256",
+ "crypto/subtle",
+ "crypto/tls",
+ "crypto/x509",
+ "crypto/xtea",
+ "debug/dwarf",
+ "debug/macho",
+ "debug/elf",
+ "debug/gosym",
+ "debug/proc",
+ "ebnf",
+ "encoding/ascii85",
+ "encoding/base64",
+ "encoding/binary",
+ "encoding/git85",
+ "encoding/hex",
+ "encoding/pem",
+ "exec",
+ "exp/datafmt",
+ "exp/draw",
+ "exp/eval",
+ "exp/exception",
+ "exp/iterable",
+ "exp/parser",
+ "expvar",
+ "flag",
+ "fmt",
+ "go/ast",
+ "go/doc",
+ "go/parser",
+ "go/printer",
+ "go/scanner",
+ "go/token",
+ "gob",
+ "hash",
+ "hash/adler32",
+ "hash/crc32",
+ "http",
+ "image",
+ "image/jpeg",
+ "image/png",
+ "io",
+ "io/ioutil",
+ "json",
+ "log",
+ "math",
+ "net",
+ "once",
+ "os",
+ "os/signal",
+ "patch",
+ "path",
+ "rand",
+ "reflect",
+ "regexp",
+ "rpc",
+ "runtime",
+ "scanner",
+ "sort",
+ "strconv",
+ "strings",
+ "sync",
+ "syscall",
+ "syslog",
+ "tabwriter",
+ "template",
+ "testing",
+ "testing/iotest",
+ "testing/quick",
+ "testing/script",
+ "time",
+ "unicode",
+ "utf8",
+ "websocket",
+ "xgb",
+ "xml",
+}