forgot file

contrib/backends/srndv2/src/srnd/thumbnails.go

@@ -0,0 +1,88 @@
+package srnd
+
+import (
+	"bytes"
+	"errors"
+	"log"
+	"mime"
+	"os/exec"
+	"path/filepath"
+	"regexp"
+	"sort"
+	"strings"
+	stdtemplate "text/template"
+)
+
+var ErrNoThumbnailerFound = errors.New("no thumbnailer found")
+
+type ThumbnailRule struct {
+	AcceptsMimeType string
+	CommandTemplate string
+}
+
+func (th *ThumbnailRule) GenerateThumbnail(infname, outfname string, env map[string]string) (err error) {
+	env["infile"] = infname
+	env["outfile"] = outfname
+	buff := new(bytes.Buffer)
+	err = stdtemplate.Must(stdtemplate.New("").Parse(th.CommandTemplate)).Execute(buff, env)
+	if err == nil {
+		args := strings.Split(buff.String(), " ")
+		cmd := exec.Command(args[0], args[1:]...)
+		var out []byte
+		out, err = cmd.CombinedOutput()
+		if err != nil {
+			log.Println(buff.String(), string(out))
+		}
+	}
+	return
+}
+
+func (th *ThumbnailRule) Accepts(mimetype string) bool {
+	return regexp.MustCompile(th.AcceptsMimeType).MatchString(mimetype)
+}
+
+func (th *ThumbnailConfig) Load(opts map[string]string) {
+	for k, v := range opts {
+		th.rules = append(th.rules, ThumbnailRule{
+			AcceptsMimeType: k,
+			CommandTemplate: v,
+		})
+	}
+	sort.Sort(th)
+}
+
+func (th *ThumbnailConfig) Len() int {
+	return len(th.rules)
+}
+
+func (th *ThumbnailConfig) Swap(i, j int) {
+	th.rules[i], th.rules[j] = th.rules[j], th.rules[i]
+}
+
+func (th *ThumbnailConfig) Less(i, j int) bool {
+	return th.rules[i].AcceptsMimeType < th.rules[j].AcceptsMimeType
+}
+
+func (th *ThumbnailConfig) FindRulesFor(mimetype string) (rules []ThumbnailRule) {
+	for _, rule := range th.rules {
+		if rule.Accepts(mimetype) {
+			rules = append(rules, rule)
+		}
+	}
+	return
+}
+
+func (th *ThumbnailConfig) GenerateThumbnail(infname, outfname string, env map[string]string) (err error) {
+	mimeType := mime.TypeByExtension(filepath.Ext(infname))
+	rules := th.FindRulesFor(mimeType)
+	for _, rule := range rules {
+		err = rule.GenerateThumbnail(infname, outfname, env)
+		if err == nil {
+			return
+		}
+	}
+	if len(rules) == 0 {
+		err = ErrNoThumbnailerFound
+	}
+	return
+}