github.com/graybobo/golang.org-package-offline-cache@v0.0.0-20200626051047-6608995c132f/x/tools/godoc/redirect/redirect.go (about)

     1  // Copyright 2013 The Go Authors. All rights reserved.
     2  // Use of this source code is governed by a BSD-style
     3  // license that can be found in the LICENSE file.
     4  
     5  // Package redirect provides hooks to register HTTP handlers that redirect old
     6  // godoc paths to their new equivalents and assist in accessing the issue
     7  // tracker, wiki, code review system, etc.
     8  package redirect // import "golang.org/x/tools/godoc/redirect"
     9  
    10  import (
    11  	"fmt"
    12  	"net/http"
    13  	"os"
    14  	"regexp"
    15  	"strconv"
    16  	"strings"
    17  )
    18  
    19  // Register registers HTTP handlers that redirect old godoc paths to their new
    20  // equivalents and assist in accessing the issue tracker, wiki, code review
    21  // system, etc. If mux is nil it uses http.DefaultServeMux.
    22  func Register(mux *http.ServeMux) {
    23  	if mux == nil {
    24  		mux = http.DefaultServeMux
    25  	}
    26  	handlePathRedirects(mux, pkgRedirects, "/pkg/")
    27  	handlePathRedirects(mux, cmdRedirects, "/cmd/")
    28  	for prefix, redirect := range prefixHelpers {
    29  		p := "/" + prefix + "/"
    30  		mux.Handle(p, PrefixHandler(p, redirect))
    31  	}
    32  	for path, redirect := range redirects {
    33  		mux.Handle(path, Handler(redirect))
    34  	}
    35  	// NB: /src/pkg (sans trailing slash) is the index of packages.
    36  	mux.HandleFunc("/src/pkg/", srcPkgHandler)
    37  	mux.HandleFunc("/cl/", clHandler)
    38  	mux.HandleFunc("/change/", changeHandler)
    39  	mux.HandleFunc("/design/", designHandler)
    40  }
    41  
    42  func handlePathRedirects(mux *http.ServeMux, redirects map[string]string, prefix string) {
    43  	for source, target := range redirects {
    44  		h := Handler(prefix + target + "/")
    45  		p := prefix + source
    46  		mux.Handle(p, h)
    47  		mux.Handle(p+"/", h)
    48  	}
    49  }
    50  
    51  // Packages that were renamed between r60 and go1.
    52  var pkgRedirects = map[string]string{
    53  	"asn1":              "encoding/asn1",
    54  	"big":               "math/big",
    55  	"cmath":             "math/cmplx",
    56  	"csv":               "encoding/csv",
    57  	"exec":              "os/exec",
    58  	"exp/template/html": "html/template",
    59  	"gob":               "encoding/gob",
    60  	"http":              "net/http",
    61  	"http/cgi":          "net/http/cgi",
    62  	"http/fcgi":         "net/http/fcgi",
    63  	"http/httptest":     "net/http/httptest",
    64  	"http/pprof":        "net/http/pprof",
    65  	"json":              "encoding/json",
    66  	"mail":              "net/mail",
    67  	"rand":              "math/rand",
    68  	"rpc":               "net/rpc",
    69  	"rpc/jsonrpc":       "net/rpc/jsonrpc",
    70  	"scanner":           "text/scanner",
    71  	"smtp":              "net/smtp",
    72  	"tabwriter":         "text/tabwriter",
    73  	"template":          "text/template",
    74  	"template/parse":    "text/template/parse",
    75  	"url":               "net/url",
    76  	"utf16":             "unicode/utf16",
    77  	"utf8":              "unicode/utf8",
    78  	"xml":               "encoding/xml",
    79  }
    80  
    81  // Commands that were renamed between r60 and go1.
    82  var cmdRedirects = map[string]string{
    83  	"gofix":     "fix",
    84  	"goinstall": "go",
    85  	"gopack":    "pack",
    86  	"gotest":    "go",
    87  	"govet":     "vet",
    88  	"goyacc":    "yacc",
    89  }
    90  
    91  var redirects = map[string]string{
    92  	"/blog":       "/blog/",
    93  	"/build":      "http://build.golang.org",
    94  	"/change":     "https://go.googlesource.com/go",
    95  	"/cl":         "https://go-review.googlesource.com",
    96  	"/cmd/godoc/": "http://godoc.org/golang.org/x/tools/cmd/godoc/",
    97  	"/issue":      "https://github.com/golang/go/issues",
    98  	"/issue/new":  "https://github.com/golang/go/issues/new",
    99  	"/issues":     "https://github.com/golang/go/issues",
   100  	"/issues/new": "https://github.com/golang/go/issues/new",
   101  	"/play":       "http://play.golang.org",
   102  	"/design":     "https://github.com/golang/proposal/tree/master/design",
   103  
   104  	// In Go 1.2 the references page is part of /doc/.
   105  	"/ref": "/doc/#references",
   106  	// This next rule clobbers /ref/spec and /ref/mem.
   107  	// TODO(adg): figure out what to do here, if anything.
   108  	// "/ref/": "/doc/#references",
   109  
   110  	// Be nice to people who are looking in the wrong place.
   111  	"/doc/mem":  "/ref/mem",
   112  	"/doc/spec": "/ref/spec",
   113  
   114  	"/talks": "http://talks.golang.org",
   115  	"/tour":  "http://tour.golang.org",
   116  	"/wiki":  "https://github.com/golang/go/wiki",
   117  
   118  	"/doc/articles/c_go_cgo.html":                    "/blog/c-go-cgo",
   119  	"/doc/articles/concurrency_patterns.html":        "/blog/go-concurrency-patterns-timing-out-and",
   120  	"/doc/articles/defer_panic_recover.html":         "/blog/defer-panic-and-recover",
   121  	"/doc/articles/error_handling.html":              "/blog/error-handling-and-go",
   122  	"/doc/articles/gobs_of_data.html":                "/blog/gobs-of-data",
   123  	"/doc/articles/godoc_documenting_go_code.html":   "/blog/godoc-documenting-go-code",
   124  	"/doc/articles/gos_declaration_syntax.html":      "/blog/gos-declaration-syntax",
   125  	"/doc/articles/image_draw.html":                  "/blog/go-imagedraw-package",
   126  	"/doc/articles/image_package.html":               "/blog/go-image-package",
   127  	"/doc/articles/json_and_go.html":                 "/blog/json-and-go",
   128  	"/doc/articles/json_rpc_tale_of_interfaces.html": "/blog/json-rpc-tale-of-interfaces",
   129  	"/doc/articles/laws_of_reflection.html":          "/blog/laws-of-reflection",
   130  	"/doc/articles/slices_usage_and_internals.html":  "/blog/go-slices-usage-and-internals",
   131  	"/doc/go_for_cpp_programmers.html":               "/wiki/GoForCPPProgrammers",
   132  	"/doc/go_tutorial.html":                          "http://tour.golang.org/",
   133  }
   134  
   135  var prefixHelpers = map[string]string{
   136  	"issue":  "https://github.com/golang/go/issues/",
   137  	"issues": "https://github.com/golang/go/issues/",
   138  	"play":   "http://play.golang.org/",
   139  	"talks":  "http://talks.golang.org/",
   140  	"wiki":   "https://github.com/golang/go/wiki/",
   141  }
   142  
   143  func Handler(target string) http.Handler {
   144  	return http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
   145  		url := target
   146  		if qs := r.URL.RawQuery; qs != "" {
   147  			url += "?" + qs
   148  		}
   149  		http.Redirect(w, r, url, http.StatusMovedPermanently)
   150  	})
   151  }
   152  
   153  var validId = regexp.MustCompile(`^[A-Za-z0-9-]*$`)
   154  
   155  func PrefixHandler(prefix, baseURL string) http.Handler {
   156  	return http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
   157  		if p := r.URL.Path; p == prefix {
   158  			// redirect /prefix/ to /prefix
   159  			http.Redirect(w, r, p[:len(p)-1], http.StatusFound)
   160  			return
   161  		}
   162  		id := r.URL.Path[len(prefix):]
   163  		if !validId.MatchString(id) {
   164  			http.Error(w, "Not found", http.StatusNotFound)
   165  			return
   166  		}
   167  		target := baseURL + id
   168  		http.Redirect(w, r, target, http.StatusFound)
   169  	})
   170  }
   171  
   172  // Redirect requests from the old "/src/pkg/foo" to the new "/src/foo".
   173  // See http://golang.org/s/go14nopkg
   174  func srcPkgHandler(w http.ResponseWriter, r *http.Request) {
   175  	r.URL.Path = "/src/" + r.URL.Path[len("/src/pkg/"):]
   176  	http.Redirect(w, r, r.URL.String(), http.StatusMovedPermanently)
   177  }
   178  
   179  func clHandler(w http.ResponseWriter, r *http.Request) {
   180  	const prefix = "/cl/"
   181  	if p := r.URL.Path; p == prefix {
   182  		// redirect /prefix/ to /prefix
   183  		http.Redirect(w, r, p[:len(p)-1], http.StatusFound)
   184  		return
   185  	}
   186  	id := r.URL.Path[len(prefix):]
   187  	// support /cl/152700045/, which is used in commit 0edafefc36.
   188  	id = strings.TrimSuffix(id, "/")
   189  	if !validId.MatchString(id) {
   190  		http.Error(w, "Not found", http.StatusNotFound)
   191  		return
   192  	}
   193  	target := ""
   194  	// the first CL in rietveld is about 152046, so only treat the id as
   195  	// a rietveld CL if it is larger than 150000.
   196  	if n, err := strconv.Atoi(id); err == nil && n > 150000 {
   197  		target = "https://codereview.appspot.com/" + id
   198  	} else {
   199  		target = "https://go-review.googlesource.com/r/" + id
   200  	}
   201  	http.Redirect(w, r, target, http.StatusFound)
   202  }
   203  
   204  var changeMap *hashMap
   205  
   206  // LoadChangeMap loads the specified map of Mercurial to Git revisions,
   207  // which is used by the /change/ handler to intelligently map old hg
   208  // revisions to their new git equivalents.
   209  // It should be called before calling Register.
   210  // The file should remain open as long as the process is running.
   211  // See the implementation of this package for details.
   212  func LoadChangeMap(filename string) error {
   213  	f, err := os.Open(filename)
   214  	if err != nil {
   215  		return err
   216  	}
   217  	m, err := newHashMap(f)
   218  	if err != nil {
   219  		return err
   220  	}
   221  	changeMap = m
   222  	return nil
   223  }
   224  
   225  func changeHandler(w http.ResponseWriter, r *http.Request) {
   226  	const prefix = "/change/"
   227  	if p := r.URL.Path; p == prefix {
   228  		// redirect /prefix/ to /prefix
   229  		http.Redirect(w, r, p[:len(p)-1], http.StatusFound)
   230  		return
   231  	}
   232  	hash := r.URL.Path[len(prefix):]
   233  	target := "https://go.googlesource.com/go/+/" + hash
   234  	if git := changeMap.Lookup(hash); git > 0 {
   235  		target = fmt.Sprintf("https://go.googlesource.com/%v/+/%v", git.Repo(), git.Hash())
   236  	}
   237  	http.Redirect(w, r, target, http.StatusFound)
   238  }
   239  
   240  func designHandler(w http.ResponseWriter, r *http.Request) {
   241  	const prefix = "/design/"
   242  	if p := r.URL.Path; p == prefix {
   243  		// redirect /prefix/ to /prefix
   244  		http.Redirect(w, r, p[:len(p)-1], http.StatusFound)
   245  		return
   246  	}
   247  	name := r.URL.Path[len(prefix):]
   248  	target := "https://github.com/golang/proposal/blob/master/design/" + name + ".md"
   249  	http.Redirect(w, r, target, http.StatusFound)
   250  }