improve parsing of desktop entries.

- speed up parsing by not creating nearly as many strings. - fix basic whitespace handling. fixes #4 goos: linux goarch: amd64 pkg: github.com/nwg-piotr/nwg-drawer cpu: AMD Ryzen 7 1800X Eight-Core Processor BenchmarkDesktopEntryParserOld-16 10000 146094 ns/op BenchmarkDesktopEntryParser-16 26097 43303 ns/op PASS ok github.com/nwg-piotr/nwg-drawer 3.090s
2021-08-31 06:06:56 -04:00
parent c5e39f179f
commit 57826c064d
4 changed files with 247 additions and 93 deletions
--- a/xdgdesktop_parser.go
+++ b/xdgdesktop_parser.go
@@ -0,0 +1,166 @@
+package main
+
+import (
+	"bufio"
+	"fmt"
+	"io"
+	"os"
+	"strconv"
+	"strings"
+)
+
+func parseDesktopEntryFileDeprecated(id string, path string) (entry desktopEntry, err error) {
+	lines, err := loadTextFile(path)
+	if err != nil {
+		return entry, err
+	}
+
+	return parseDesktopEntryDeprecated(id, lines)
+}
+
+func parseDesktopEntryDeprecated(id string, lines []string) (entry desktopEntry, err error) {
+	desktopID := id
+	name := ""
+	nameLoc := ""
+	comment := ""
+	commentLoc := ""
+	icon := ""
+	exec := ""
+	categories := ""
+	terminal := false
+	noDisplay := false
+
+	for _, l := range lines {
+		if strings.HasPrefix(l, "[") && l != "[Desktop Entry]" {
+			break
+		}
+		if strings.HasPrefix(l, "Name=") {
+			name = strings.Split(l, "=")[1]
+			continue
+		}
+		if strings.HasPrefix(l, fmt.Sprintf("Name[%s]=", strings.Split(*lang, "_")[0])) {
+			nameLoc = strings.Split(l, "=")[1]
+			continue
+		}
+		if strings.HasPrefix(l, "Comment=") {
+			comment = strings.Split(l, "=")[1]
+			continue
+		}
+		if strings.HasPrefix(l, fmt.Sprintf("Comment[%s]=", strings.Split(*lang, "_")[0])) {
+			commentLoc = strings.Split(l, "=")[1]
+			continue
+		}
+		if strings.HasPrefix(l, "Icon=") {
+			icon = strings.Split(l, "=")[1]
+			continue
+		}
+		if strings.HasPrefix(l, "Exec=") {
+			exec = strings.Split(l, "Exec=")[1]
+			disallowed := [2]string{"\"", "'"}
+			for _, char := range disallowed {
+				exec = strings.Replace(exec, char, "", -1)
+			}
+			continue
+		}
+		if strings.HasPrefix(l, "Categories=") {
+			categories = strings.Split(l, "Categories=")[1]
+			continue
+		}
+		if l == "Terminal=true" {
+			terminal = true
+			continue
+		}
+		if l == "NoDisplay=true" {
+			noDisplay = true
+			continue
+		}
+	}
+
+	// if name[ln] not found, let's try to find name[ln_LN]
+	if nameLoc == "" {
+		nameLoc = name
+	}
+	if commentLoc == "" {
+		commentLoc = comment
+	}
+
+	entry.DesktopID = desktopID
+	entry.Name = name
+	entry.NameLoc = nameLoc
+	entry.Comment = comment
+	entry.CommentLoc = commentLoc
+	entry.Icon = icon
+	entry.Exec = exec
+	entry.Terminal = terminal
+	entry.NoDisplay = noDisplay
+	entry.Category = categories
+	return entry, nil
+}
+
+func parseDesktopEntryFile(id string, path string) (e desktopEntry, err error) {
+	o, err := os.Open(path)
+	if err != nil {
+		return e, err
+	}
+	defer o.Close()
+
+	return parseDesktopEntry(id, o)
+}
+
+func parseDesktopEntry(id string, in io.Reader) (entry desktopEntry, err error) {
+	cleanexec := strings.NewReplacer("\"", "", "'", "")
+	entry.DesktopID = id
+	localizedName := fmt.Sprintf("Name[%s]", strings.Split(*lang, "_")[0])
+	localizedComment := fmt.Sprintf("Comment[%s]", strings.Split(*lang, "_")[0])
+	scanner := bufio.NewScanner(in)
+	scanner.Split(bufio.ScanLines)
+
+	for scanner.Scan() {
+		l := scanner.Text()
+		if strings.HasPrefix(l, "[") && l != "[Desktop Entry]" {
+			break
+		}
+
+		name, value := parseKeypair(l)
+		if value == "" {
+			continue
+		}
+
+		switch name {
+		case "Name":
+			entry.Name = value
+		case localizedName:
+			entry.NameLoc = value
+		case "Comment":
+			entry.Comment = value
+		case localizedComment:
+			entry.CommentLoc = value
+		case "Icon":
+			entry.Icon = value
+		case "Categories":
+			entry.Category = value
+		case "Terminal":
+			entry.Terminal, _ = strconv.ParseBool(value)
+		case "NoDisplay":
+			entry.NoDisplay, _ = strconv.ParseBool(value)
+		case "Exec":
+			entry.Exec = cleanexec.Replace(value)
+		}
+	}
+
+	// if name[ln] not found, let's try to find name[ln_LN]
+	if entry.NameLoc == "" {
+		entry.NameLoc = entry.Name
+	}
+	if entry.CommentLoc == "" {
+		entry.CommentLoc = entry.Comment
+	}
+	return entry, err
+}
+
+func parseKeypair(s string) (string, string) {
+	if idx := strings.IndexRune(s, '='); idx > 0 {
+		return strings.TrimSpace(s[:idx]), strings.TrimSpace(s[idx+1:])
+	}
+	return s, ""
+}