Optimize memory usage of epgtrim/epgpruner

Do not read entire file into the memory. Instead filter junk on the fly
while reading the file.

1 files changed, 0 insertions, 206 deletions

diff --git a/epgpruner/epgpruner.go b/epgpruner/epgpruner.go
deleted file mode 100644
index b2a4f54..0000000
--- a/epgpruner/epgpruner.go
+++ /dev/null
@@ -1,206 +0,0 @@
-package main
-
-import (
-	"compress/gzip"
-	"encoding/xml"
-	"flag"
-	"fmt"
-	"io"
-	"log"
-	"net/http"
-	"os"
-	"regexp"
-	"strings"
-)
-
-var (
-	docType = `<!DOCTYPE tv SYSTEM "xmltv.dtd">`
-
-	epgRE     = regexp.MustCompile(`url-tvg="([a-z0-9-:/.]+)"`)
-	channelRE = regexp.MustCompile(`tvg-id="([a-z0-9-]+)"`)
-)
-
-func usage() {
-	fmt.Fprintf(os.Stderr, "usage: epgpruner URL\n")
-	flag.PrintDefaults()
-	os.Exit(2)
-}
-
-func main() {
-	flag.Usage = usage
-	flag.Parse()
-	if flag.NArg() != 1 {
-		usage()
-		os.Exit(1)
-	}
-	playlistURL := flag.Args()[0]
-	playlist := Playlist{
-		URL: playlistURL,
-	}
-	err := playlist.Fetch()
-	if err != nil {
-		log.Fatal(err)
-	}
-
-	playlist.Reduce()
-
-	reducedEpg, err := xml.MarshalIndent(playlist.Epg, "", "    ")
-	if err != nil {
-		log.Fatal(err)
-	}
-	fmt.Println(
-		xml.Header +
-			docType + "\n" +
-			string(reducedEpg),
-	)
-}
-
-type Playlist struct {
-	URL      string
-	EpgURL   string
-	Channels map[string]struct{}
-	Epg      Epg
-}
-
-func (p *Playlist) Fetch() error {
-	compressed := false
-	body, err := fetch(p.URL, compressed)
-	if err != nil {
-		return err
-	}
-	err = p.parse(body)
-	if err != nil {
-		return err
-	}
-
-	compressed = true
-	body, err = fetch(p.EpgURL, compressed)
-	if err != nil {
-		return err
-	}
-
-	err = xml.Unmarshal(body, &p.Epg)
-	if err != nil {
-		return err
-	}
-
-	return nil
-}
-
-func fetch(url string, compressed bool) ([]byte, error) {
-	resp, err := http.Get(url)
-	if err != nil {
-		return make([]byte, 0), err
-	}
-	if resp.StatusCode != http.StatusOK {
-		return make([]byte, 0),
-			fmt.Errorf("Bad reponse status: %d", resp.StatusCode)
-	}
-	reader := resp.Body
-	defer reader.Close()
-	if compressed {
-		reader, err = gzip.NewReader(reader)
-		if err != nil {
-			return make([]byte, 0), err
-		}
-	}
-	body, err := io.ReadAll(reader)
-	if err != nil {
-		return make([]byte, 0), err
-	}
-	return body, nil
-}
-
-func (p *Playlist) parse(body []byte) error {
-	epgURL := ""
-	channels := make(map[string]struct{})
-	for _, line := range strings.Split(string(body), "\n") {
-		if strings.HasPrefix(line, "#EXTM3U") {
-			m := epgRE.FindStringSubmatch(line)
-			if m == nil {
-				return fmt.Errorf(
-					"Couldn't match EPG url from: `%s`",
-					line,
-				)
-			}
-			epgURL = m[1]
-		} else if strings.HasPrefix(line, "#EXTINF") {
-			m := channelRE.FindStringSubmatch(line)
-			if m == nil {
-				return fmt.Errorf(
-					"Couldn't match channel name from: `%s`",
-					line,
-				)
-			}
-			channel := m[1]
-			channels[channel] = struct{}{}
-		}
-	}
-
-	p.EpgURL = epgURL
-	p.Channels = channels
-
-	return nil
-}
-
-func (p *Playlist) Reduce() {
-	channels := make([]Channel, 0)
-	programmes := make([]Programme, 0)
-
-	for _, channel := range p.Epg.Channels {
-		if _, ok := p.Channels[channel.ID]; !ok {
-			continue
-		}
-		channels = append(channels, channel)
-	}
-
-	for _, programme := range p.Epg.Programmes {
-		if _, ok := p.Channels[programme.Channel]; !ok {
-			continue
-		}
-		programmes = append(programmes, programme)
-	}
-
-	p.Epg.Channels = channels
-	p.Epg.Programmes = programmes
-}
-
-type Epg struct {
-	XMLName    xml.Name    `xml:"tv"`
-	Info       string      `xml:"generator-info-name,attr"`
-	Channels   []Channel   `xml:"channel"`
-	Programmes []Programme `xml:"programme"`
-}
-
-type Channel struct {
-	ID          string      `xml:"id,attr"`
-	DisplayName DisplayName `xml:"display-name"`
-	Icon        Icon        `xml:"icon"`
-}
-
-type DisplayName struct {
-	Lang string `xml:"lang,attr"`
-	Name string `xml:",chardata"`
-}
-
-type Icon struct {
-	Src string `xml:"src,attr"`
-}
-
-type Programme struct {
-	Start   string `xml:"start,attr"`
-	Stop    string `xml:"stop,attr"`
-	Channel string `xml:"channel,attr"`
-	Title   Title  `xml:"title,omitempty"`
-	Desc    Desc   `xml:"desc,omitempty"`
-}
-
-type Title struct {
-	Lang  string `xml:"lang,attr"`
-	Title string `xml:",chardata"`
-}
-
-type Desc struct {
-	Lang string `xml:"lang,attr"`
-	Desc string `xml:",chardata"`
-}