Merge pull request #143 from go-enry/re-collation-at-codegen

Move venrod RE collation at codegen

internal/code-generator/generator/test_files/vendor.gold

@@ -173,3 +173,6 @@ var VendorMatchers = []regex.EnryRegexp{
 	regex.MustCompile(`(^|/)\.gitpod\.Dockerfile$`),
 	regex.MustCompile(`(^|/)\.github/`),
 }
+
+// FastVendorMatcher is equivalent to matching any of the VendorMatchers.
+var FastVendorMatcher = regex.MustCompile(`(?:^(?:(?:[Dd]ependencies/)|(?:debian/)|(?:deps/)|(?:rebar$)))|(?:(?:^|/)(?:(?:BuddyBuildSDK\.framework/)|(?:Carthage/)|(?:Chart\.js$)|(?:Control\.FullScreen\.css)|(?:Control\.FullScreen\.js)|(?:Crashlytics\.framework/)|(?:Fabric\.framework/)|(?:Godeps/_workspace/)|(?:Jenkinsfile$)|(?:Leaflet\.Coordinates-\d+\.\d+\.\d+\.src\.js$)|(?:MathJax/)|(?:MochiKit\.js$)|(?:RealmSwift\.framework)|(?:Realm\.framework)|(?:Sparkle/)|(?:Vagrantfile$)|(?:[Bb]ourbon/.*\.(css|less|scss|styl)$)|(?:[Cc]ode[Mm]irror/(\d+\.\d+/)?(lib|mode|theme|addon|keymap|demo))|(?:[Ee]xtern(als?)?/)|(?:[Mm]icrosoft([Mm]vc)?([Aa]jax|[Vv]alidation)(\.debug)?\.js$)|(?:[Pp]ackages\/.+\.\d+\/)|(?:[Ss]pecs?/fixtures/)|(?:[Tt]ests?/fixtures/)|(?:[Vv]+endor/)|(?:\.[Dd][Ss]_[Ss]tore$)|(?:\.gitattributes$)|(?:\.github/)|(?:\.gitignore$)|(?:\.gitmodules$)|(?:\.gitpod\.Dockerfile$)|(?:\.google_apis/)|(?:\.indent\.pro)|(?:\.mvn/wrapper/)|(?:\.osx$)|(?:\.sublime-project)|(?:\.sublime-workspace)|(?:\.vscode/)|(?:\.yarn/plugins/)|(?:\.yarn/releases/)|(?:\.yarn/sdks/)|(?:\.yarn/unplugged/)|(?:\.yarn/versions/)|(?:_esy$)|(?:ace-builds/)|(?:aclocal\.m4)|(?:activator$)|(?:activator\.bat$)|(?:admin_media/)|(?:angular([^.]*)\.js$)|(?:animate\.(css|less|scss|styl)$)|(?:bootbox\.js)|(?:bootstrap([^/.]*)\.(js|css|less|scss|styl)$)|(?:bootstrap-datepicker/)|(?:bower_components/)|(?:bulma\.(css|sass|scss)$)|(?:cache/)|(?:ckeditor\.js$)|(?:config\.guess$)|(?:config\.sub$)|(?:configure$)|(?:controls\.js$)|(?:cordova([^.]*)\.js$)|(?:cordova\-\d\.\d(\.\d)?\.js$)|(?:cpplint\.py)|(?:custom\.bootstrap([^\s]*)(js|css|less|scss|styl)$)|(?:dist/)|(?:docs?/_?(build|themes?|templates?|static)/)|(?:dojo\.js$)|(?:dotnet-install\.(ps1|sh)$)|(?:dragdrop\.js$)|(?:effects\.js$)|(?:env/)|(?:erlang\.mk)|(?:extjs/.*?\.html$)|(?:extjs/.*?\.js$)|(?:extjs/.*?\.properties$)|(?:extjs/.*?\.txt$)|(?:extjs/.*?\.xml$)|(?:extjs/\.sencha/)|(?:extjs/builds/)|(?:extjs/cmd/)|(?:extjs/docs/)|(?:extjs/examples/)|(?:extjs/locale/)|(?:extjs/packages/)|(?:extjs/plugins/)|(?:extjs/resources/)|(?:extjs/src/)|(?:extjs/welcome/)|(?:fabfile\.py$)|(?:flow-typed/.*\.js$)|(?:font-?awesome/.*\.(css|less|scss|styl)$)|(?:font-?awesome\.(css|less|scss|styl)$)|(?:fontello(.*?)\.css$)|(?:foundation(\..*)?\.js$)|(?:foundation\.(css|less|scss|styl)$)|(?:fuelux\.js)|(?:gradle/wrapper/)|(?:gradlew$)|(?:gradlew\.bat$)|(?:html5shiv\.js$)|(?:inst/extdata/)|(?:jquery([^.]*)\.js$)|(?:jquery([^.]*)\.unobtrusive\-ajax\.js$)|(?:jquery([^.]*)\.validate(\.unobtrusive)?\.js$)|(?:jquery\-\d\.\d+(\.\d+)?\.js$)|(?:jquery\-ui(\-\d\.\d+(\.\d+)?)?(\.\w+)?\.(js|css)$)|(?:jquery\.(ui|effects)\.([^.]*)\.(js|css)$)|(?:jquery\.dataTables\.js)|(?:jquery\.fancybox\.(js|css))|(?:jquery\.fileupload(-\w+)?\.js$)|(?:jquery\.fn\.gantt\.js)|(?:knockout-(\d+\.){3}(debug\.)?js$)|(?:leaflet\.draw-src\.js)|(?:leaflet\.draw\.css)|(?:leaflet\.spin\.js)|(?:libtool\.m4)|(?:ltoptions\.m4)|(?:ltsugar\.m4)|(?:ltversion\.m4)|(?:lt~obsolete\.m4)|(?:materialize\.(css|less|scss|styl|js)$)|(?:modernizr\-\d\.\d+(\.\d+)?\.js$)|(?:modernizr\.custom\.\d+\.js$)|(?:mootools([^.]*)\d+\.\d+.\d+([^.]*)\.js$)|(?:mvnw$)|(?:mvnw\.cmd$)|(?:node_modules/)|(?:normalize\.(css|less|scss|styl)$)|(?:octicons\.css)|(?:pdf\.worker\.js)|(?:proguard-rules\.pro$)|(?:proguard\.pro$)|(?:prototype(.*)\.js$)|(?:puphpet/)|(?:react(-[^.]*)?\.js$)|(?:run\.n$)|(?:select2/.*\.(css|scss|js)$)|(?:shBrush([^.]*)\.js$)|(?:shCore\.js$)|(?:shLegacy\.js$)|(?:skeleton\.(css|less|scss|styl)$)|(?:slick\.\w+.js$)|(?:sprockets-octicons\.scss)|(?:testdata/)|(?:tiny_mce([^.]*)\.js$)|(?:tiny_mce/(langs|plugins|themes|utils))|(?:vendors?/)|(?:vignettes/)|(?:waf$)|(?:wicket-leaflet\.js)|(?:yahoo-([^.]*)\.js$)|(?:yui([^.]*)\.js$)))|(?:(.*?)\.d\.ts$)|(?:(3rd|[Tt]hird)[-_]?[Pp]arty/)|(?:([^\s]*)import\.(css|less|scss|styl)$)|(?:(\.|-)min\.(js|css)$)|(?:(^|\/)d3(\.v\d+)?([^.]*)\.js$)|(?:-vsdoc\.js$)|(?:\.imageset/)|(?:\.intellisense\.js$)|(?:\.xctemplate/)`)

internal/code-generator/generator/vendor.go

@@ -2,8 +2,12 @@ package generator
 
 import (
 	"bytes"
+	"fmt"
 	"io"
 	"io/ioutil"
+	"sort"
+	"strings"
+	"text/template"
 
 	"gopkg.in/yaml.v2"
 )
@@ -16,19 +20,97 @@ func Vendor(fileToParse, samplesDir, outPath, tmplPath, tmplName, commit string)
 		return err
 	}
 
-	var regexpList []string
-	if err := yaml.Unmarshal(data, &regexpList); err != nil {
-		return nil
+	var regexps []string
+	if err := yaml.Unmarshal(data, &regexps); err != nil {
+		return fmt.Errorf("failed to parse YAML %s, %q", fileToParse, err)
 	}
 
 	buf := &bytes.Buffer{}
-	if err := executeVendorTemplate(buf, regexpList, tmplPath, tmplName, commit); err != nil {
-		return nil
+	if err := executeVendorTemplate(buf, regexps, tmplPath, tmplName, commit); err != nil {
+		return err
 	}
 
 	return formatedWrite(outPath, buf.Bytes())
 }
 
-func executeVendorTemplate(out io.Writer, regexpList []string, tmplPath, tmplName, commit string) error {
-	return executeTemplate(out, tmplName, tmplPath, commit, nil, regexpList)
+func executeVendorTemplate(out io.Writer, regexps []string, tmplPath, tmplName, commit string) error {
+	funcs := template.FuncMap{"optimize": collateAllMatchers}
+	return executeTemplate(out, tmplName, tmplPath, commit, funcs, regexps)
+}
+
+func collateAllMatchers(regexps []string) string {
+	// We now collate all regexps from VendorMatchers to a single large regexp
+	// which is at least twice as fast to test than simply iterating & matching.
+	//
+	// ---
+	//
+	// We could test each matcher from VendorMatchers in turn i.e.
+	//
+	//  	func IsVendor(filename string) bool {
+	// 			for _, matcher := range data.VendorMatchers {
+	// 				if matcher.MatchString(filename) {
+	//					return true
+	//				}
+	//			}
+	//			return false
+	//		}
+	//
+	// Or naïvely concatentate all these regexps using groups i.e.
+	//
+	//		`(regexp1)|(regexp2)|(regexp3)|...`
+	//
+	// However, both of these are relatively slow and don't take advantage
+	// of the inherent structure within our regexps.
+	//
+	// Imperical observation: by looking at the regexps, we only have 3 types.
+	//  1. Those that start with `^`
+	//  2. Those that start with `(^|/)`
+	//  3. All the rest
+	//
+	// If we collate our regexps into these 3 groups - that will significantly
+	// reduce the likelihood of backtracking within the regexp trie matcher.
+	//
+	// A further improvement is to use non-capturing groups (?:) as otherwise
+	// the regexp parser, whilst matching, will have to allocate slices for
+	// matching positions. (A future improvement left out could be to
+	// enforce non-capturing groups within the sub-regexps.)
+	const (
+		caret        = "^"
+		caretOrSlash = "(^|/)"
+	)
+
+	sort.Strings(regexps)
+
+	var caretPrefixed, caretOrSlashPrefixed, theRest []string
+	// Check prefix, add to the respective group slices
+	for _, re := range regexps {
+		if strings.HasPrefix(re, caret) {
+			caretPrefixed = append(caretPrefixed, re[len(caret):])
+		} else if strings.HasPrefix(re, caretOrSlash) {
+			caretOrSlashPrefixed = append(caretOrSlashPrefixed, re[len(caretOrSlash):])
+		} else {
+			theRest = append(theRest, re)
+		}
+	}
+	var sb strings.Builder
+	appendGroupWithCommonPrefix(&sb, "^", caretPrefixed)
+	sb.WriteString("|")
+
+	appendGroupWithCommonPrefix(&sb, "(?:^|/)", caretOrSlashPrefixed)
+	sb.WriteString("|")
+
+	appendGroupWithCommonPrefix(&sb, "", theRest)
+	return sb.String()
+}
+
+func appendGroupWithCommonPrefix(sb *strings.Builder, commonPrefix string, res []string) {
+	sb.WriteString("(?:")
+	if commonPrefix != "" {
+		sb.WriteString(fmt.Sprintf("%s(?:(?:", commonPrefix))
+	}
+	sb.WriteString(strings.Join(res, ")|(?:"))
+	if commonPrefix != "" {
+		sb.WriteString("))")
+	}
+	sb.WriteString(")")
 }