Improve file extension checking performance

file.go

@@ -261,15 +261,12 @@ func (i *File) GetFileType(checkContent bool) error {
 
 	// If the type isn't text (and is blob for example), it will check some
 	// common types that are mistaken not to be text.
-	for _, extension := range textExtensions {
-		if strings.HasSuffix(i.Name, extension) {
-			i.Type = "text"
-			goto End
-		}
+	if isInTextExtensions(i.Name) {
+		i.Type = "text"
+	} else {
+		i.Type = "blob"
 	}
 
-	i.Type = "blob"
-
 End:
 	// If the file type is text, save its content.
 	if i.Type == "text" {
@@ -415,23 +412,38 @@ func (l byModified) Less(i, j int) bool {
 	return iModified.Sub(jModified) < 0
 }
 
-var textExtensions = [...]string{
-	".md", ".markdown", ".mdown", ".mmark",
-	".asciidoc", ".adoc", ".ad",
-	".rst",
-	".tml", ".yml",
-	".json", ".toml", ".yaml", ".csv", ".xml", ".rss", ".conf", ".ini",
-	".tex", ".sty",
-	".css", ".sass", ".scss",
-	".js",
-	".html",
-	".txt", ".rtf",
-	".sh", ".bash", ".ps1", ".bat", ".cmd",
-	".php", ".pl", ".py",
+// textExtensions is the sorted list of text extensions which
+// can be edited.
+var textExtensions = []string{
+	".ad", ".ada", ".adoc", ".asciidoc",
+	".bas", ".bash", ".bat",
+	".c", ".cc", ".cmd", ".conf", ".cpp", ".cr", ".cs", ".css", ".csv",
+	".d",
+	".f", ".f90",
+	".h", ".hh", ".hpp", ".htaccess", ".html",
+	".ini",
+	".java", ".js", ".json",
+	".markdown", ".md", ".mdown", ".mmark",
+	".nim",
+	".php", ".pl", ".ps1", ".py",
+	".rss", ".rst", ".rtf",
+	".sass", ".scss", ".sh", ".sty",
+	".tex", ".tml", ".toml", ".txt",
+	".vala", ".vapi",
+	".xml",
+	".yaml", ".yml",
 	"Caddyfile",
-	".htaccess",
-	".c", ".cc", ".h", ".hh", ".cpp", ".hpp", ".f90",
-	".f", ".bas", ".d", ".ada", ".nim", ".cr", ".java", ".cs", ".vala", ".vapi",
+}
+
+// isInTextExtensions checks if a file can be edited by its extensions.
+func isInTextExtensions(name string) bool {
+	search := filepath.Ext(name)
+	if search == "" {
+		search = name
+	}
+
+	i := sort.SearchStrings(textExtensions, search)
+	return i < len(textExtensions) && textExtensions[i] == search
 }
 
 // hasRune checks if the file has the frontmatter rune