src/cmd/godoc/main.go - go - Git at Google

 // Copyright 2009 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.

 // godoc: Go Documentation Server

 // Web server tree:
 //
 //	http://godoc/		main landing page
 //	http://godoc/doc/	serve from $GOROOT/doc - spec, mem, tutorial, etc.
 //	http://godoc/src/	serve files from $GOROOT/src; .go gets pretty-printed
 //	http://godoc/cmd/	serve documentation about commands
 //	http://godoc/pkg/	serve documentation about packages
 //				(idea is if you say import "compress/zlib", you go to
 //				http://godoc/pkg/compress/zlib)
 //
 // Command-line interface:
 //
 //	godoc packagepath [name ...]
 //
 //	godoc compress/zlib
 //		- prints doc for package compress/zlib
 //	godoc crypto/block Cipher NewCMAC
 //		- prints doc for Cipher and NewCMAC in package crypto/block

 package main

 import (
 	"bytes"
 	_ "expvar" // to serve /debug/vars
 	"flag"
 	"fmt"
 	"go/ast"
 	"go/build"
 	"http"
 	_ "http/pprof" // to serve /debug/pprof/*
 	"io"
 	"log"
 	"os"
 	"path/filepath"
 	"regexp"
 	"runtime"
 	"strings"
 	"time"
 )

 const defaultAddr = ":6060" // default webserver address

 var (
 	// periodic sync
 	syncCmd   = flag.String("sync", "", "sync command; disabled if empty")
 	syncMin   = flag.Int("sync_minutes", 0, "sync interval in minutes; disabled if <= 0")
 	syncDelay delayTime // actual sync interval in minutes; usually syncDelay == syncMin, but syncDelay may back off exponentially

 	// network
 	httpAddr   = flag.String("http", "", "HTTP service address (e.g., '"+defaultAddr+"')")
 	serverAddr = flag.String("server", "", "webserver address for command line searches")

 	// layout control
 	html    = flag.Bool("html", false, "print HTML in command-line mode")
 	srcMode = flag.Bool("src", false, "print (exported) source in command-line mode")

 	// command-line searches
 	query = flag.Bool("q", false, "arguments are considered search queries")
 )


 func serveError(w http.ResponseWriter, r *http.Request, relpath string, err os.Error) {
 	contents := applyTemplate(errorHTML, "errorHTML", err) // err may contain an absolute path!
 	w.WriteHeader(http.StatusNotFound)
 	servePage(w, "File "+relpath, "", "", contents)
 }


 func exec(rw http.ResponseWriter, args []string) (status int) {
 	r, w, err := os.Pipe()
 	if err != nil {
 		log.Printf("os.Pipe(): %v", err)
 		return 2
 	}

 	bin := args[0]
 	fds := []*os.File{nil, w, w}
 	if *verbose {
 		log.Printf("executing %v", args)
 	}
 	p, err := os.StartProcess(bin, args, &os.ProcAttr{Files: fds, Dir: *goroot})
 	defer r.Close()
 	w.Close()
 	if err != nil {
 		log.Printf("os.StartProcess(%q): %v", bin, err)
 		return 2
 	}
 	defer p.Release()

 	var buf bytes.Buffer
 	io.Copy(&buf, r)
 	wait, err := p.Wait(0)
 	if err != nil {
 		os.Stderr.Write(buf.Bytes())
 		log.Printf("os.Wait(%d, 0): %v", p.Pid, err)
 		return 2
 	}
 	status = wait.ExitStatus()
 	if !wait.Exited() || status > 1 {
 		os.Stderr.Write(buf.Bytes())
 		log.Printf("executing %v failed (exit status = %d)", args, status)
 		return
 	}

 	if *verbose {
 		os.Stderr.Write(buf.Bytes())
 	}
 	if rw != nil {
 		rw.Header().Set("Content-Type", "text/plain; charset=utf-8")
 		rw.Write(buf.Bytes())
 	}

 	return
 }


 func dosync(w http.ResponseWriter, r *http.Request) {
 	args := []string{"/bin/sh", "-c", *syncCmd}
 	switch exec(w, args) {
 	case 0:
 		// sync succeeded and some files have changed;
 		// update package tree.
 		// TODO(gri): The directory tree may be temporarily out-of-sync.
 		//            Consider keeping separate time stamps so the web-
 		//            page can indicate this discrepancy.
 		initFSTree()
 		fallthrough
 	case 1:
 		// sync failed because no files changed;
 		// don't change the package tree
 		syncDelay.set(*syncMin) //  revert to regular sync schedule
 	default:
 		// sync failed because of an error - back off exponentially, but try at least once a day
 		syncDelay.backoff(24 * 60)
 	}
 }


 func usage() {
 	fmt.Fprintf(os.Stderr,
 		"usage: godoc package [name ...]\n"+
 			"	godoc -http="+defaultAddr+"\n")
 	flag.PrintDefaults()
 	os.Exit(2)
 }


 func loggingHandler(h http.Handler) http.Handler {
 	return http.HandlerFunc(func(w http.ResponseWriter, req *http.Request) {
 		log.Printf("%s\t%s", req.RemoteAddr, req.URL)
 		h.ServeHTTP(w, req)
 	})
 }


 func remoteSearch(query string) (res *http.Response, err os.Error) {
 	search := "/search?f=text&q=" + http.URLEscape(query)

 	// list of addresses to try
 	var addrs []string
 	if *serverAddr != "" {
 		// explicit server address - only try this one
 		addrs = []string{*serverAddr}
 	} else {
 		addrs = []string{
 			defaultAddr,
 			"golang.org",
 		}
 	}

 	// remote search
 	for _, addr := range addrs {
 		url := "http://" + addr + search
 		res, err = http.Get(url)
 		if err == nil && res.StatusCode == http.StatusOK {
 			break
 		}
 	}

 	if err == nil && res.StatusCode != http.StatusOK {
 		err = os.NewError(res.Status)
 	}

 	return
 }


 // Does s look like a regular expression?
 func isRegexp(s string) bool {
 	return strings.IndexAny(s, ".(|)*+?^$[]") >= 0
 }


 // Make a regular expression of the form
 // names[0]|names[1]|...names[len(names)-1].
 // Returns nil if the regular expression is illegal.
 func makeRx(names []string) (rx *regexp.Regexp) {
 	if len(names) > 0 {
 		s := ""
 		for i, name := range names {
 			if i > 0 {
 				s += "|"
 			}
 			if isRegexp(name) {
 				s += name
 			} else {
 				s += "^" + name + "$" // must match exactly
 			}
 		}
 		rx, _ = regexp.Compile(s) // rx is nil if there's a compilation error
 	}
 	return
 }


 func main() {
 	flag.Usage = usage
 	flag.Parse()

 	// Determine file system to use.
 	// TODO(gri) Complete this - for now we only have one.
 	fs = OS

 	// Clean goroot: normalize path separator.
 	*goroot = filepath.Clean(*goroot)

 	// Check usage: either server and no args, or command line and args
 	if (*httpAddr != "") != (flag.NArg() == 0) {
 		usage()
 	}

 	if *tabwidth < 0 {
 		log.Fatalf("negative tabwidth %d", *tabwidth)
 	}

 	initHandlers()
 	readTemplates()

 	if *httpAddr != "" {
 		// HTTP server mode.
 		var handler http.Handler = http.DefaultServeMux
 		if *verbose {
 			log.Printf("Go Documentation Server")
 			log.Printf("version = %s", runtime.Version())
 			log.Printf("address = %s", *httpAddr)
 			log.Printf("goroot = %s", *goroot)
 			log.Printf("tabwidth = %d", *tabwidth)
 			switch {
 			case !*indexEnabled:
 				log.Print("search index disabled")
 			case *maxResults > 0:
 				log.Printf("full text index enabled (maxresults = %d)", *maxResults)
 			default:
 				log.Print("identifier search index enabled")
 			}
 			if !fsMap.IsEmpty() {
 				log.Print("user-defined mapping:")
 				fsMap.Fprint(os.Stderr)
 			}
 			handler = loggingHandler(handler)
 		}

 		registerPublicHandlers(http.DefaultServeMux)
 		if *syncCmd != "" {
 			http.Handle("/debug/sync", http.HandlerFunc(dosync))
 		}

 		// Initialize default directory tree with corresponding timestamp.
 		// (Do it in a goroutine so that launch is quick.)
 		go initFSTree()

 		// Initialize directory trees for user-defined file systems (-path flag).
 		initDirTrees()

 		// Start sync goroutine, if enabled.
 		if *syncCmd != "" && *syncMin > 0 {
 			syncDelay.set(*syncMin) // initial sync delay
 			go func() {
 				for {
 					dosync(nil, nil)
 					delay, _ := syncDelay.get()
 					if *verbose {
 						log.Printf("next sync in %dmin", delay.(int))
 					}
 					time.Sleep(int64(delay.(int)) * 60e9)
 				}
 			}()
 		}

 		// Start indexing goroutine.
 		if *indexEnabled {
 			go indexer()
 		}

 		// Start http server.
 		if err := http.ListenAndServe(*httpAddr, handler); err != nil {
 			log.Fatalf("ListenAndServe %s: %v", *httpAddr, err)
 		}

 		return
 	}

 	// Command line mode.
 	if *html {
 		packageText = packageHTML
 		searchText = packageHTML
 	}

 	if *query {
 		// Command-line queries.
 		for i := 0; i < flag.NArg(); i++ {
 			res, err := remoteSearch(flag.Arg(i))
 			if err != nil {
 				log.Fatalf("remoteSearch: %s", err)
 			}
 			io.Copy(os.Stdout, res.Body)
 		}
 		return
 	}

 	// determine paths
 	path := flag.Arg(0)
 	if len(path) > 0 && path[0] == '.' {
 		// assume cwd; don't assume -goroot
 		cwd, _ := os.Getwd() // ignore errors
 		path = filepath.Join(cwd, path)
 	}
 	relpath := path
 	abspath := path
 	if t, pkg, err := build.FindTree(path); err == nil {
 		relpath = pkg
 		abspath = filepath.Join(t.SrcDir(), pkg)
 	} else if !filepath.IsAbs(path) {
 		abspath = absolutePath(path, pkgHandler.fsRoot)
 	} else {
 		relpath = relativeURL(path)
 	}

 	var mode PageInfoMode
 	if *srcMode {
 		// only filter exports if we don't have explicit command-line filter arguments
 		if flag.NArg() == 1 {
 			mode |= exportsOnly
 		}
 	} else {
 		mode = exportsOnly | genDoc
 	}
 	// TODO(gri): Provide a mechanism (flag?) to select a package
 	//            if there are multiple packages in a directory.
 	info := pkgHandler.getPageInfo(abspath, relpath, "", mode)

 	if info.IsEmpty() {
 		// try again, this time assume it's a command
 		if !filepath.IsAbs(path) {
 			abspath = absolutePath(path, cmdHandler.fsRoot)
 		}
 		cmdInfo := cmdHandler.getPageInfo(abspath, relpath, "", mode)
 		// only use the cmdInfo if it actually contains a result
 		// (don't hide errors reported from looking up a package)
 		if !cmdInfo.IsEmpty() {
 			info = cmdInfo
 		}
 	}
 	if info.Err != nil {
 		log.Fatalf("%v", info.Err)
 	}

 	// If we have more than one argument, use the remaining arguments for filtering
 	if flag.NArg() > 1 {
 		args := flag.Args()[1:]
 		rx := makeRx(args)
 		if rx == nil {
 			log.Fatalf("illegal regular expression from %v", args)
 		}

 		filter := func(s string) bool { return rx.MatchString(s) }
 		switch {
 		case info.PAst != nil:
 			ast.FilterFile(info.PAst, filter)
 			// Special case: Don't use templates for printing
 			// so we only get the filtered declarations without
 			// package clause or extra whitespace.
 			for i, d := range info.PAst.Decls {
 				if i > 0 {
 					fmt.Println()
 				}
 				if *html {
 					writeAnyHTML(os.Stdout, info.FSet, d)
 				} else {
 					writeAny(os.Stdout, info.FSet, d)
 				}
 				fmt.Println()
 			}
 			return

 		case info.PDoc != nil:
 			info.PDoc.Filter(filter)
 		}
 	}

 	if err := packageText.Execute(os.Stdout, info); err != nil {
 		log.Printf("packageText.Execute: %s", err)
 	}
 }
	// Copyright 2009 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.

	// godoc: Go Documentation Server

	// Web server tree:
	//
	// http://godoc/ main landing page
	// http://godoc/doc/ serve from $GOROOT/doc - spec, mem, tutorial, etc.
	// http://godoc/src/ serve files from $GOROOT/src; .go gets pretty-printed
	// http://godoc/cmd/ serve documentation about commands
	// http://godoc/pkg/ serve documentation about packages
	// (idea is if you say import "compress/zlib", you go to
	// http://godoc/pkg/compress/zlib)
	//
	// Command-line interface:
	//
	// godoc packagepath [name ...]
	//
	// godoc compress/zlib
	// - prints doc for package compress/zlib
	// godoc crypto/block Cipher NewCMAC
	// - prints doc for Cipher and NewCMAC in package crypto/block

	package main

	import (
	"bytes"
	_ "expvar" // to serve /debug/vars
	"flag"
	"fmt"
	"go/ast"
	"go/build"
	"http"
	_ "http/pprof" // to serve /debug/pprof/*
	"io"
	"log"
	"os"
	"path/filepath"
	"regexp"
	"runtime"
	"strings"
	"time"
	)

	const defaultAddr = ":6060" // default webserver address

	var (
	// periodic sync
	syncCmd = flag.String("sync", "", "sync command; disabled if empty")
	syncMin = flag.Int("sync_minutes", 0, "sync interval in minutes; disabled if <= 0")
	syncDelay delayTime // actual sync interval in minutes; usually syncDelay == syncMin, but syncDelay may back off exponentially

	// network
	httpAddr = flag.String("http", "", "HTTP service address (e.g., '"+defaultAddr+"')")
	serverAddr = flag.String("server", "", "webserver address for command line searches")

	// layout control
	html = flag.Bool("html", false, "print HTML in command-line mode")
	srcMode = flag.Bool("src", false, "print (exported) source in command-line mode")

	// command-line searches
	query = flag.Bool("q", false, "arguments are considered search queries")
	)


	func serveError(w http.ResponseWriter, r *http.Request, relpath string, err os.Error) {
	contents := applyTemplate(errorHTML, "errorHTML", err) // err may contain an absolute path!
	w.WriteHeader(http.StatusNotFound)
	servePage(w, "File "+relpath, "", "", contents)
	}


	func exec(rw http.ResponseWriter, args []string) (status int) {
	r, w, err := os.Pipe()
	if err != nil {
	log.Printf("os.Pipe(): %v", err)
	return 2
	}

	bin := args[0]
	fds := []*os.File{nil, w, w}
	if *verbose {
	log.Printf("executing %v", args)
	}
	p, err := os.StartProcess(bin, args, &os.ProcAttr{Files: fds, Dir: *goroot})
	defer r.Close()
	w.Close()
	if err != nil {
	log.Printf("os.StartProcess(%q): %v", bin, err)
	return 2
	}
	defer p.Release()

	var buf bytes.Buffer
	io.Copy(&buf, r)
	wait, err := p.Wait(0)
	if err != nil {
	os.Stderr.Write(buf.Bytes())
	log.Printf("os.Wait(%d, 0): %v", p.Pid, err)
	return 2
	}
	status = wait.ExitStatus()
	if !wait.Exited() \|\| status > 1 {
	os.Stderr.Write(buf.Bytes())
	log.Printf("executing %v failed (exit status = %d)", args, status)
	return
	}

	if *verbose {
	os.Stderr.Write(buf.Bytes())
	}
	if rw != nil {
	rw.Header().Set("Content-Type", "text/plain; charset=utf-8")
	rw.Write(buf.Bytes())
	}

	return
	}


	func dosync(w http.ResponseWriter, r *http.Request) {
	args := []string{"/bin/sh", "-c", *syncCmd}
	switch exec(w, args) {
	case 0:
	// sync succeeded and some files have changed;
	// update package tree.
	// TODO(gri): The directory tree may be temporarily out-of-sync.
	// Consider keeping separate time stamps so the web-
	// page can indicate this discrepancy.
	initFSTree()
	fallthrough
	case 1:
	// sync failed because no files changed;
	// don't change the package tree
	syncDelay.set(*syncMin) // revert to regular sync schedule
	default:
	// sync failed because of an error - back off exponentially, but try at least once a day
	syncDelay.backoff(24 * 60)
	}
	}


	func usage() {
	fmt.Fprintf(os.Stderr,
	"usage: godoc package [name ...]\n"+
	" godoc -http="+defaultAddr+"\n")
	flag.PrintDefaults()
	os.Exit(2)
	}


	func loggingHandler(h http.Handler) http.Handler {
	return http.HandlerFunc(func(w http.ResponseWriter, req *http.Request) {
	log.Printf("%s\t%s", req.RemoteAddr, req.URL)
	h.ServeHTTP(w, req)
	})
	}


	func remoteSearch(query string) (res *http.Response, err os.Error) {
	search := "/search?f=text&q=" + http.URLEscape(query)

	// list of addresses to try
	var addrs []string
	if *serverAddr != "" {
	// explicit server address - only try this one
	addrs = []string{*serverAddr}
	} else {
	addrs = []string{
	defaultAddr,
	"golang.org",
	}
	}

	// remote search
	for _, addr := range addrs {
	url := "http://" + addr + search
	res, err = http.Get(url)
	if err == nil && res.StatusCode == http.StatusOK {
	break
	}
	}

	if err == nil && res.StatusCode != http.StatusOK {
	err = os.NewError(res.Status)
	}

	return
	}


	// Does s look like a regular expression?
	func isRegexp(s string) bool {
	return strings.IndexAny(s, ".(\|)*+?^$[]") >= 0
	}


	// Make a regular expression of the form
	// names[0]\|names[1]\|...names[len(names)-1].
	// Returns nil if the regular expression is illegal.
	func makeRx(names []string) (rx *regexp.Regexp) {
	if len(names) > 0 {
	s := ""
	for i, name := range names {
	if i > 0 {
	s += "\|"
	}
	if isRegexp(name) {
	s += name
	} else {
	s += "^" + name + "$" // must match exactly
	}
	}
	rx, _ = regexp.Compile(s) // rx is nil if there's a compilation error
	}
	return
	}


	func main() {
	flag.Usage = usage
	flag.Parse()

	// Determine file system to use.
	// TODO(gri) Complete this - for now we only have one.
	fs = OS

	// Clean goroot: normalize path separator.
	goroot = filepath.Clean(goroot)

	// Check usage: either server and no args, or command line and args
	if (*httpAddr != "") != (flag.NArg() == 0) {
	usage()
	}

	if *tabwidth < 0 {
	log.Fatalf("negative tabwidth %d", *tabwidth)
	}

	initHandlers()
	readTemplates()

	if *httpAddr != "" {
	// HTTP server mode.
	var handler http.Handler = http.DefaultServeMux
	if *verbose {
	log.Printf("Go Documentation Server")
	log.Printf("version = %s", runtime.Version())
	log.Printf("address = %s", *httpAddr)
	log.Printf("goroot = %s", *goroot)
	log.Printf("tabwidth = %d", *tabwidth)
	switch {
	case !*indexEnabled:
	log.Print("search index disabled")
	case *maxResults > 0:
	log.Printf("full text index enabled (maxresults = %d)", *maxResults)
	default:
	log.Print("identifier search index enabled")
	}
	if !fsMap.IsEmpty() {
	log.Print("user-defined mapping:")
	fsMap.Fprint(os.Stderr)
	}
	handler = loggingHandler(handler)
	}

	registerPublicHandlers(http.DefaultServeMux)
	if *syncCmd != "" {
	http.Handle("/debug/sync", http.HandlerFunc(dosync))
	}

	// Initialize default directory tree with corresponding timestamp.
	// (Do it in a goroutine so that launch is quick.)
	go initFSTree()

	// Initialize directory trees for user-defined file systems (-path flag).
	initDirTrees()

	// Start sync goroutine, if enabled.
	if syncCmd != "" && syncMin > 0 {
	syncDelay.set(*syncMin) // initial sync delay
	go func() {
	for {
	dosync(nil, nil)
	delay, _ := syncDelay.get()
	if *verbose {
	log.Printf("next sync in %dmin", delay.(int))
	}
	time.Sleep(int64(delay.(int)) * 60e9)
	}
	}()
	}

	// Start indexing goroutine.
	if *indexEnabled {
	go indexer()
	}

	// Start http server.
	if err := http.ListenAndServe(*httpAddr, handler); err != nil {
	log.Fatalf("ListenAndServe %s: %v", *httpAddr, err)
	}

	return
	}

	// Command line mode.
	if *html {
	packageText = packageHTML
	searchText = packageHTML
	}

	if *query {
	// Command-line queries.
	for i := 0; i < flag.NArg(); i++ {
	res, err := remoteSearch(flag.Arg(i))
	if err != nil {
	log.Fatalf("remoteSearch: %s", err)
	}
	io.Copy(os.Stdout, res.Body)
	}
	return
	}

	// determine paths
	path := flag.Arg(0)
	if len(path) > 0 && path[0] == '.' {
	// assume cwd; don't assume -goroot
	cwd, _ := os.Getwd() // ignore errors
	path = filepath.Join(cwd, path)
	}
	relpath := path
	abspath := path
	if t, pkg, err := build.FindTree(path); err == nil {
	relpath = pkg
	abspath = filepath.Join(t.SrcDir(), pkg)
	} else if !filepath.IsAbs(path) {
	abspath = absolutePath(path, pkgHandler.fsRoot)
	} else {
	relpath = relativeURL(path)
	}

	var mode PageInfoMode
	if *srcMode {
	// only filter exports if we don't have explicit command-line filter arguments
	if flag.NArg() == 1 {
	mode \|= exportsOnly
	}
	} else {
	mode = exportsOnly \| genDoc
	}
	// TODO(gri): Provide a mechanism (flag?) to select a package
	// if there are multiple packages in a directory.
	info := pkgHandler.getPageInfo(abspath, relpath, "", mode)

	if info.IsEmpty() {
	// try again, this time assume it's a command
	if !filepath.IsAbs(path) {
	abspath = absolutePath(path, cmdHandler.fsRoot)
	}
	cmdInfo := cmdHandler.getPageInfo(abspath, relpath, "", mode)
	// only use the cmdInfo if it actually contains a result
	// (don't hide errors reported from looking up a package)
	if !cmdInfo.IsEmpty() {
	info = cmdInfo
	}
	}
	if info.Err != nil {
	log.Fatalf("%v", info.Err)
	}

	// If we have more than one argument, use the remaining arguments for filtering
	if flag.NArg() > 1 {
	args := flag.Args()[1:]
	rx := makeRx(args)
	if rx == nil {
	log.Fatalf("illegal regular expression from %v", args)
	}

	filter := func(s string) bool { return rx.MatchString(s) }
	switch {
	case info.PAst != nil:
	ast.FilterFile(info.PAst, filter)
	// Special case: Don't use templates for printing
	// so we only get the filtered declarations without
	// package clause or extra whitespace.
	for i, d := range info.PAst.Decls {
	if i > 0 {
	fmt.Println()
	}
	if *html {
	writeAnyHTML(os.Stdout, info.FSet, d)
	} else {
	writeAny(os.Stdout, info.FSet, d)
	}
	fmt.Println()
	}
	return

	case info.PDoc != nil:
	info.PDoc.Filter(filter)
	}
	}

	if err := packageText.Execute(os.Stdout, info); err != nil {
	log.Printf("packageText.Execute: %s", err)
	}
	}