devapp/owners/owners.go - build - Git at Google

 // Copyright 2018 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.

 package owners

 import (
 	"bytes"
 	"encoding/json"
 	"fmt"
 	"html/template"
 	"log"
 	"net/http"
 	"strings"
 	"sync"

 	"golang.org/x/build/repos"
 )

 type Owner struct {
 	// GitHubUsername is a GitHub user name or team name.
 	GitHubUsername string `json:"githubUsername"`
 	GerritEmail    string `json:"gerritEmail"`
 }

 type Entry struct {
 	Primary   []Owner `json:"primary"`
 	Secondary []Owner `json:"secondary,omitempty"`
 }

 type Request struct {
 	Payload struct {
 		Paths []string `json:"paths"`
 	} `json:"payload"`
 	Version int `json:"v"` // API version
 }

 type Response struct {
 	Payload struct {
 		Entries map[string]*Entry `json:"entries"` // paths in request -> Entry
 	} `json:"payload"`
 	Error string `json:"error,omitempty"`
 }

 // match takes a path consisting of the repo name and full path of a file or
 // directory within that repo and returns the deepest Entry match in the file
 // hierarchy for the given resource.
 func match(path string) *Entry {
 	var deepestPath string
 	for p := range entries {
 		if hasPathPrefix(path, p) && len(p) > len(deepestPath) {
 			deepestPath = p
 		}
 	}
 	return entries[deepestPath]
 }

 // hasPathPrefix reports whether the slash-separated path s
 // begins with the elements in prefix.
 //
 // Copied from go/src/cmd/go/internal/str.HasPathPrefix.
 func hasPathPrefix(s, prefix string) bool {
 	if len(s) == len(prefix) {
 		return s == prefix
 	}
 	if prefix == "" {
 		return true
 	}
 	if len(s) > len(prefix) {
 		if prefix[len(prefix)-1] == '/' || s[len(prefix)] == '/' {
 			return s[:len(prefix)] == prefix
 		}
 	}
 	return false
 }

 // Handler takes one or more paths and returns a map of each to a matching
 // Entry struct. If no Entry is matched for the path, the value for the key
 // is nil.
 func Handler(w http.ResponseWriter, r *http.Request) {
 	w.Header().Set("Access-Control-Allow-Origin", "*")
 	w.Header().Set("Content-Type", "application/json")

 	switch r.Method {
 	case "GET":
 		serveIndex(w, r)
 		return
 	case "POST":
 		var req Request
 		if err := json.NewDecoder(r.Body).Decode(&req); err != nil {
 			jsonError(w, "unable to decode request", http.StatusBadRequest)
 			// TODO: increment expvar for monitoring.
 			log.Printf("unable to decode owners request: %v", err)
 			return
 		}

 		var resp Response
 		resp.Payload.Entries = make(map[string]*Entry)
 		for _, p := range req.Payload.Paths {
 			resp.Payload.Entries[p] = match(p)
 		}
 		var buf bytes.Buffer
 		if err := json.NewEncoder(&buf).Encode(resp); err != nil {
 			jsonError(w, "unable to encode response", http.StatusInternalServerError)
 			// TODO: increment expvar for monitoring.
 			log.Printf("unable to encode owners response: %v", err)
 			return
 		}
 		w.Write(buf.Bytes())
 	case "OPTIONS":
 		// Likely a CORS preflight request; leave resp.Payload empty.
 	default:
 		jsonError(w, http.StatusText(http.StatusMethodNotAllowed), http.StatusMethodNotAllowed)
 		return
 	}
 }

 func jsonError(w http.ResponseWriter, text string, code int) {
 	w.WriteHeader(code)
 	var buf bytes.Buffer
 	if err := json.NewEncoder(&buf).Encode(Response{Error: text}); err != nil {
 		// TODO: increment expvar for monitoring.
 		log.Printf("unable to encode error response: %v", err)
 		return
 	}
 	w.Write(buf.Bytes())
 }

 // translatePath takes a path for a package based on go.googlesource.com
 // and translates it into a form that aligns more closely with the issue
 // tracker.
 //
 // Specifically, Go standard library packages lose the go/src prefix,
 // repositories with a golang.org/x/ import path get the x/ prefix,
 // and all other paths are left as-is (this includes e.g. domains).
 func translatePath(path string) string {
 	// Check if it's in the standard library, in which case,
 	// drop the prefix.
 	if strings.HasPrefix(path, "go/src/") {
 		return path[len("go/src/"):]
 	}

 	// Check if it's some other path in the main repo, in which case,
 	// drop the go/ prefix.
 	if strings.HasPrefix(path, "go/") {
 		return path[len("go/"):]
 	}

 	// Check if it's a golang.org/x/ repository, and if so add an x/ prefix.
 	firstComponent := path
 	i := strings.IndexRune(path, '/')
 	if i > 0 {
 		firstComponent = path[:i]
 	}
 	if _, ok := repos.ByImportPath["golang.org/x/"+firstComponent]; ok {
 		return "x/" + path
 	}

 	// None of the above was true, so just leave it untouched.
 	return path
 }

 // translateOwnersPaths returns a copy of entries with all its keys
 // adjusted for better readability on https://dev.golang.org/owners.
 func translateOwnersPaths() (map[string]*Entry, error) {
 	tm := make(map[string]*Entry)
 	for path, entry := range entries {
 		tPath := translatePath(path)
 		if _, ok := tm[tPath]; ok {
 			return nil, fmt.Errorf("path translation of %q creates a duplicate entry %q", path, tPath)
 		}
 		tm[tPath] = entry
 	}
 	return tm, nil
 }

 func serveIndex(w http.ResponseWriter, r *http.Request) {
 	w.Header().Set("Content-Type", "text/html; charset=utf-8")

 	indexCache.once.Do(func() {
 		displayEntries, err := translateOwnersPaths()
 		if err != nil {
 			indexCache.err = err
 			return
 		}
 		var buf bytes.Buffer
 		indexCache.err = indexTmpl.Execute(&buf, displayEntries)
 		indexCache.html = buf.Bytes()
 	})
 	if indexCache.err != nil {
 		log.Printf("unable to serve index page HTML: %v", indexCache.err)
 		http.Error(w, http.StatusText(http.StatusInternalServerError), http.StatusInternalServerError)
 		return
 	}
 	w.Write(indexCache.html)
 }

 // indexCache is a cache of the owners index page HTML.
 //
 // As long as the owners are defined at package initialization time
 // and not modified at runtime, the HTML doesn't change per request.
 var indexCache struct {
 	once sync.Once
 	html []byte // Page HTML rendered by indexTmpl.
 	err  error
 }

 var indexTmpl = template.Must(template.New("index").Funcs(template.FuncMap{
 	"githubURL": func(githubUsername string) string {
 		if i := strings.Index(githubUsername, "/"); i != -1 {
 			// A GitHub team like "{org}/{team}".
 			org, team := githubUsername[:i], githubUsername[i+len("/"):]
 			return "https://github.com/orgs/" + org + "/teams/" + team
 		}
 		return "https://github.com/" + githubUsername
 	},
 }).Parse(`<!DOCTYPE html>
 <html lang="en">
 <title>Go Code Owners</title>
 <meta name=viewport content="width=device-width, initial-scale=1">
 <style>
 * {
 	box-sizing: border-box;
 	margin: 0;
 	padding: 0;
 }
 body {
 	font-family: sans-serif;
 	margin: 1rem 1.5rem;
 }
 .header {
 	color: #666;
 	font-size: 90%;
 	margin-bottom: 1rem;
 }
 .table-header {
 	font-weight: bold;
 	position: sticky;
 	top: 0;
 }
 .table-header,
 .entry {
 	background-color: #fff;
 	border-bottom: 1px solid #ddd;
 	display: flex;
 	flex-wrap: wrap;
 	justify-content: space-between;
 	margin: .15rem 0;
 	padding: .15rem 0;
 }
 .path,
 .primary,
 .secondary {
 	flex-basis: 33.3%;
 }
 </style>
 <header class="header">
 	Alter these entries at
 	<a href="https://go.googlesource.com/build/+/master/devapp/owners"
 		target="_blank" rel="noopener">golang.org/x/build/devapp/owners</a>
 </header>
 <main>
 <div class="table-header">
 	<span class="path">Path</span>
 	<span class="primary">Primaries</span>
 	<span class="secondary">Secondaries</span>
 </div>
 {{range $path, $entry := .}}
 	<div class="entry">
 		<span class="path">{{$path}}</span>
 		<span class="primary">
 			{{range .Primary}}
 				<a href="{{githubURL .GitHubUsername}}" target="_blank" rel="noopener">@{{.GitHubUsername}}</a>
 			{{end}}
 		</span>
 		<span class="secondary">
 			{{range .Secondary}}
 				<a href="{{githubURL .GitHubUsername}}" target="_blank" rel="noopener">@{{.GitHubUsername}}</a>
 			{{end}}
 		</span>
 	</div>
 {{end}}
 </main>
 `))
	// Copyright 2018 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.

	package owners

	import (
	"bytes"
	"encoding/json"
	"fmt"
	"html/template"
	"log"
	"net/http"
	"strings"
	"sync"

	"golang.org/x/build/repos"
	)

	type Owner struct {
	// GitHubUsername is a GitHub user name or team name.
	GitHubUsername string `json:"githubUsername"`
	GerritEmail string `json:"gerritEmail"`
	}

	type Entry struct {
	Primary []Owner `json:"primary"`
	Secondary []Owner `json:"secondary,omitempty"`
	}

	type Request struct {
	Payload struct {
	Paths []string `json:"paths"`
	} `json:"payload"`
	Version int `json:"v"` // API version
	}

	type Response struct {
	Payload struct {
	Entries map[string]*Entry `json:"entries"` // paths in request -> Entry
	} `json:"payload"`
	Error string `json:"error,omitempty"`
	}

	// match takes a path consisting of the repo name and full path of a file or
	// directory within that repo and returns the deepest Entry match in the file
	// hierarchy for the given resource.
	func match(path string) *Entry {
	var deepestPath string
	for p := range entries {
	if hasPathPrefix(path, p) && len(p) > len(deepestPath) {
	deepestPath = p
	}
	}
	return entries[deepestPath]
	}

	// hasPathPrefix reports whether the slash-separated path s
	// begins with the elements in prefix.
	//
	// Copied from go/src/cmd/go/internal/str.HasPathPrefix.
	func hasPathPrefix(s, prefix string) bool {
	if len(s) == len(prefix) {
	return s == prefix
	}
	if prefix == "" {
	return true
	}
	if len(s) > len(prefix) {
	if prefix[len(prefix)-1] == '/' \|\| s[len(prefix)] == '/' {
	return s[:len(prefix)] == prefix
	}
	}
	return false
	}

	// Handler takes one or more paths and returns a map of each to a matching
	// Entry struct. If no Entry is matched for the path, the value for the key
	// is nil.
	func Handler(w http.ResponseWriter, r *http.Request) {
	w.Header().Set("Access-Control-Allow-Origin", "*")
	w.Header().Set("Content-Type", "application/json")

	switch r.Method {
	case "GET":
	serveIndex(w, r)
	return
	case "POST":
	var req Request
	if err := json.NewDecoder(r.Body).Decode(&req); err != nil {
	jsonError(w, "unable to decode request", http.StatusBadRequest)
	// TODO: increment expvar for monitoring.
	log.Printf("unable to decode owners request: %v", err)
	return
	}

	var resp Response
	resp.Payload.Entries = make(map[string]*Entry)
	for _, p := range req.Payload.Paths {
	resp.Payload.Entries[p] = match(p)
	}
	var buf bytes.Buffer
	if err := json.NewEncoder(&buf).Encode(resp); err != nil {
	jsonError(w, "unable to encode response", http.StatusInternalServerError)
	// TODO: increment expvar for monitoring.
	log.Printf("unable to encode owners response: %v", err)
	return
	}
	w.Write(buf.Bytes())
	case "OPTIONS":
	// Likely a CORS preflight request; leave resp.Payload empty.
	default:
	jsonError(w, http.StatusText(http.StatusMethodNotAllowed), http.StatusMethodNotAllowed)
	return
	}
	}

	func jsonError(w http.ResponseWriter, text string, code int) {
	w.WriteHeader(code)
	var buf bytes.Buffer
	if err := json.NewEncoder(&buf).Encode(Response{Error: text}); err != nil {
	// TODO: increment expvar for monitoring.
	log.Printf("unable to encode error response: %v", err)
	return
	}
	w.Write(buf.Bytes())
	}

	// translatePath takes a path for a package based on go.googlesource.com
	// and translates it into a form that aligns more closely with the issue
	// tracker.
	//
	// Specifically, Go standard library packages lose the go/src prefix,
	// repositories with a golang.org/x/ import path get the x/ prefix,
	// and all other paths are left as-is (this includes e.g. domains).
	func translatePath(path string) string {
	// Check if it's in the standard library, in which case,
	// drop the prefix.
	if strings.HasPrefix(path, "go/src/") {
	return path[len("go/src/"):]
	}

	// Check if it's some other path in the main repo, in which case,
	// drop the go/ prefix.
	if strings.HasPrefix(path, "go/") {
	return path[len("go/"):]
	}

	// Check if it's a golang.org/x/ repository, and if so add an x/ prefix.
	firstComponent := path
	i := strings.IndexRune(path, '/')
	if i > 0 {
	firstComponent = path[:i]
	}
	if _, ok := repos.ByImportPath["golang.org/x/"+firstComponent]; ok {
	return "x/" + path
	}

	// None of the above was true, so just leave it untouched.
	return path
	}

	// translateOwnersPaths returns a copy of entries with all its keys
	// adjusted for better readability on https://dev.golang.org/owners.
	func translateOwnersPaths() (map[string]*Entry, error) {
	tm := make(map[string]*Entry)
	for path, entry := range entries {
	tPath := translatePath(path)
	if _, ok := tm[tPath]; ok {
	return nil, fmt.Errorf("path translation of %q creates a duplicate entry %q", path, tPath)
	}
	tm[tPath] = entry
	}
	return tm, nil
	}

	func serveIndex(w http.ResponseWriter, r *http.Request) {
	w.Header().Set("Content-Type", "text/html; charset=utf-8")

	indexCache.once.Do(func() {
	displayEntries, err := translateOwnersPaths()
	if err != nil {
	indexCache.err = err
	return
	}
	var buf bytes.Buffer
	indexCache.err = indexTmpl.Execute(&buf, displayEntries)
	indexCache.html = buf.Bytes()
	})
	if indexCache.err != nil {
	log.Printf("unable to serve index page HTML: %v", indexCache.err)
	http.Error(w, http.StatusText(http.StatusInternalServerError), http.StatusInternalServerError)
	return
	}
	w.Write(indexCache.html)
	}

	// indexCache is a cache of the owners index page HTML.
	//
	// As long as the owners are defined at package initialization time
	// and not modified at runtime, the HTML doesn't change per request.
	var indexCache struct {
	once sync.Once
	html []byte // Page HTML rendered by indexTmpl.
	err error
	}

	var indexTmpl = template.Must(template.New("index").Funcs(template.FuncMap{
	"githubURL": func(githubUsername string) string {
	if i := strings.Index(githubUsername, "/"); i != -1 {
	// A GitHub team like "{org}/{team}".
	org, team := githubUsername[:i], githubUsername[i+len("/"):]
	return "https://github.com/orgs/" + org + "/teams/" + team
	}
	return "https://github.com/" + githubUsername
	},
	}).Parse(`<!DOCTYPE html>
	<html lang="en">
	<title>Go Code Owners</title>
	<meta name=viewport content="width=device-width, initial-scale=1">
	<style>
	* {
	box-sizing: border-box;
	margin: 0;
	padding: 0;
	}
	body {
	font-family: sans-serif;
	margin: 1rem 1.5rem;
	}
	.header {
	color: #666;
	font-size: 90%;
	margin-bottom: 1rem;
	}
	.table-header {
	font-weight: bold;
	position: sticky;
	top: 0;
	}
	.table-header,
	.entry {
	background-color: #fff;
	border-bottom: 1px solid #ddd;
	display: flex;
	flex-wrap: wrap;
	justify-content: space-between;
	margin: .15rem 0;
	padding: .15rem 0;
	}
	.path,
	.primary,
	.secondary {
	flex-basis: 33.3%;
	}
	</style>
	<header class="header">
	Alter these entries at
	<a href="https://go.googlesource.com/build/+/master/devapp/owners"
	target="_blank" rel="noopener">golang.org/x/build/devapp/owners</a>
	</header>
	<main>
	<div class="table-header">
	<span class="path">Path</span>
	<span class="primary">Primaries</span>
	<span class="secondary">Secondaries</span>
	</div>
	{{range $path, $entry := .}}
	<div class="entry">
	<span class="path">{{$path}}</span>
	<span class="primary">
	{{range .Primary}}
	<a href="{{githubURL .GitHubUsername}}" target="_blank" rel="noopener">@{{.GitHubUsername}}</a>
	{{end}}
	</span>
	<span class="secondary">
	{{range .Secondary}}
	<a href="{{githubURL .GitHubUsername}}" target="_blank" rel="noopener">@{{.GitHubUsername}}</a>
	{{end}}
	</span>
	</div>
	{{end}}
	</main>
	`))