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