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, 61 insertions, 0 deletions

diff --git a/epgtrim/epgtrim.go b/epgtrim/epgtrim.go
new file mode 100644
index 0000000..9fd8d7a
--- /dev/null
+++ b/epgtrim/epgtrim.go
@@ -0,0 +1,61 @@
+package main
+
+import (
+	"bufio"
+	"encoding/xml"
+	"flag"
+	"fmt"
+	"log"
+	"os"
+)
+
+var (
+	docType = `<!DOCTYPE tv SYSTEM "xmltv.dtd">`
+	output  = flag.String(
+		"output",
+		"-",
+		"Write output to `file` (stdout by default)",
+	)
+)
+
+func usage() {
+	fmt.Fprintf(os.Stderr, "usage: epgpruner [-output file] URL\n")
+	flag.PrintDefaults()
+	os.Exit(2)
+}
+
+func main() {
+	log.SetPrefix("epgtrim: ")
+	log.SetFlags(0)
+	flag.Usage = usage
+	flag.Parse()
+	if flag.NArg() != 1 {
+		usage()
+		os.Exit(1)
+	}
+	URL := flag.Args()[0]
+
+	playlist, err := NewPlaylist(URL)
+	if err != nil {
+		log.Fatal(err)
+	}
+
+	outfile := os.Stdout
+	if *output != "-" {
+		f, err := os.Create(*output)
+		if err != nil {
+			log.Fatal(err)
+		}
+		outfile = f
+		defer f.Close()
+	}
+	wr := bufio.NewWriter(outfile)
+	defer wr.Flush()
+	wr.Write([]byte(xml.Header + docType + "\n"))
+	e := xml.NewEncoder(wr)
+	e.Indent("", "    ")
+	err = e.Encode(playlist.Schedule.EPG)
+	if err != nil {
+		log.Fatal(err)
+	}
+}