From e1442842d5a7c91fd7df9a7ecc2939acb50c8f97 Mon Sep 17 00:00:00 2001
From: aler9 <46489434+aler9@users.noreply.github.com>
Date: Tue, 24 Dec 2024 16:08:28 +0100
Subject: [PATCH] normalize playlist primitives

---
 pkg/playlist/media.go                  | 17 ++++++------
 pkg/playlist/media_key.go              |  3 +-
 pkg/playlist/media_map.go              | 15 ++++++----
 pkg/playlist/media_part.go             | 20 +++++++++-----
 pkg/playlist/media_part_inf.go         |  8 ++++--
 pkg/playlist/media_preload_hint.go     |  3 +-
 pkg/playlist/media_segment.go          |  5 +++-
 pkg/playlist/media_server_control.go   | 11 ++++++--
 pkg/playlist/media_skip.go             |  3 +-
 pkg/playlist/multivariant.go           |  2 +-
 pkg/playlist/multivariant_rendition.go |  3 +-
 pkg/playlist/multivariant_start.go     |  8 ++++--
 pkg/playlist/multivariant_variant.go   |  3 +-
 pkg/playlist/primitives/attributes.go  | 23 +++++++++-------
 pkg/playlist/primitives/byterange.go   | 38 ++++++++++++++++----------
 pkg/playlist/primitives/duration.go    | 12 +++++---
 pkg/playlist/primitives/header.go      |  5 ++--
 17 files changed, 111 insertions(+), 68 deletions(-)

diff --git a/pkg/playlist/media.go b/pkg/playlist/media.go
index b837acc..c58b908 100644
--- a/pkg/playlist/media.go
+++ b/pkg/playlist/media.go
@@ -102,7 +102,7 @@ func (m Media) isPlaylist() {}
 func (m *Media) Unmarshal(buf []byte) error {
 	s := string(buf)
 
-	s, err := primitives.HeaderUnmarshal(s)
+	s, err := primitives.SkipHeader(s)
 	if err != nil {
 		return err
 	}
@@ -280,13 +280,13 @@ func (m *Media) Unmarshal(buf []byte) error {
 				return fmt.Errorf("invalid EXTINF: %s", line)
 			}
 
-			var du time.Duration
-			du, err = primitives.DurationUnmarshal(parts[0])
+			var d primitives.Duration
+			err = d.Unmarshal(parts[0])
 			if err != nil {
 				return err
 			}
 
-			curSegment.Duration = du
+			curSegment.Duration = time.Duration(d)
 			curSegment.Title = strings.TrimSpace(parts[1])
 
 			curSegment.Key = curKey
@@ -294,15 +294,14 @@ func (m *Media) Unmarshal(buf []byte) error {
 		case strings.HasPrefix(line, "#EXT-X-BYTERANGE:"):
 			line = line[len("#EXT-X-BYTERANGE:"):]
 
-			var tmp1 uint64
-			var tmp2 *uint64
-			tmp1, tmp2, err = primitives.ByteRangeUnmarshal(line)
+			var br primitives.ByteRange
+			err = br.Unmarshal(line)
 			if err != nil {
 				return err
 			}
 
-			curSegment.ByteRangeLength = &tmp1
-			curSegment.ByteRangeStart = tmp2
+			curSegment.ByteRangeLength = &br.Length
+			curSegment.ByteRangeStart = br.Start
 
 		case strings.HasPrefix(line, "#EXT-X-PART:"):
 			line = line[len("#EXT-X-PART:"):]
diff --git a/pkg/playlist/media_key.go b/pkg/playlist/media_key.go
index 5186738..e85359c 100644
--- a/pkg/playlist/media_key.go
+++ b/pkg/playlist/media_key.go
@@ -36,7 +36,8 @@ type MediaKey struct {
 }
 
 func (t *MediaKey) unmarshal(v string) error {
-	attrs, err := primitives.AttributesUnmarshal(v)
+	var attrs primitives.Attributes
+	err := attrs.Unmarshal(v)
 	if err != nil {
 		return err
 	}
diff --git a/pkg/playlist/media_map.go b/pkg/playlist/media_map.go
index b5a26db..197ba87 100644
--- a/pkg/playlist/media_map.go
+++ b/pkg/playlist/media_map.go
@@ -18,7 +18,8 @@ type MediaMap struct {
 }
 
 func (t *MediaMap) unmarshal(v string) error {
-	attrs, err := primitives.AttributesUnmarshal(v)
+	var attrs primitives.Attributes
+	err := attrs.Unmarshal(v)
 	if err != nil {
 		return err
 	}
@@ -29,13 +30,14 @@ func (t *MediaMap) unmarshal(v string) error {
 			t.URI = val
 
 		case "BYTERANGE":
-			length, start, err := primitives.ByteRangeUnmarshal(val)
+			var br primitives.ByteRange
+			err := br.Unmarshal(val)
 			if err != nil {
 				return err
 			}
 
-			t.ByteRangeLength = &length
-			t.ByteRangeStart = start
+			t.ByteRangeLength = &br.Length
+			t.ByteRangeStart = br.Start
 		}
 	}
 
@@ -50,7 +52,10 @@ func (t MediaMap) marshal() string {
 	ret := "#EXT-X-MAP:URI=\"" + t.URI + "\""
 
 	if t.ByteRangeLength != nil {
-		ret += ",BYTERANGE=" + primitives.ByteRangeMarshal(*t.ByteRangeLength, t.ByteRangeStart) + ""
+		ret += ",BYTERANGE=" + primitives.ByteRange{
+			Length: *t.ByteRangeLength,
+			Start:  t.ByteRangeStart,
+		}.Marshal() + ""
 	}
 
 	ret += "\n"
diff --git a/pkg/playlist/media_part.go b/pkg/playlist/media_part.go
index 059a7b7..87b7447 100644
--- a/pkg/playlist/media_part.go
+++ b/pkg/playlist/media_part.go
@@ -30,7 +30,8 @@ type MediaPart struct {
 }
 
 func (p *MediaPart) unmarshal(v string) error {
-	attrs, err := primitives.AttributesUnmarshal(v)
+	var attrs primitives.Attributes
+	err := attrs.Unmarshal(v)
 	if err != nil {
 		return err
 	}
@@ -38,11 +39,12 @@ func (p *MediaPart) unmarshal(v string) error {
 	for key, val := range attrs {
 		switch key {
 		case "DURATION":
-			tmp, err := primitives.DurationUnmarshal(val)
+			var d primitives.Duration
+			err := d.Unmarshal(val)
 			if err != nil {
 				return err
 			}
-			p.Duration = tmp
+			p.Duration = time.Duration(d)
 
 		case "URI":
 			p.URI = val
@@ -51,12 +53,13 @@ func (p *MediaPart) unmarshal(v string) error {
 			p.Independent = (val == "YES")
 
 		case "BYTERANGE":
-			length, start, err := primitives.ByteRangeUnmarshal(val)
+			var br primitives.ByteRange
+			err := br.Unmarshal(val)
 			if err != nil {
 				return err
 			}
-			p.ByteRangeLength = &length
-			p.ByteRangeStart = start
+			p.ByteRangeLength = &br.Length
+			p.ByteRangeStart = br.Start
 
 		case "GAP":
 			p.Gap = true
@@ -83,7 +86,10 @@ func (p MediaPart) marshal() string {
 	}
 
 	if p.ByteRangeLength != nil {
-		ret += ",BYTERANGE=" + primitives.ByteRangeMarshal(*p.ByteRangeLength, p.ByteRangeStart) + ""
+		ret += ",BYTERANGE=" + primitives.ByteRange{
+			Length: *p.ByteRangeLength,
+			Start:  p.ByteRangeStart,
+		}.Marshal() + ""
 	}
 
 	if p.Gap {
diff --git a/pkg/playlist/media_part_inf.go b/pkg/playlist/media_part_inf.go
index 5fca008..d760b50 100644
--- a/pkg/playlist/media_part_inf.go
+++ b/pkg/playlist/media_part_inf.go
@@ -16,18 +16,20 @@ type MediaPartInf struct {
 }
 
 func (t *MediaPartInf) unmarshal(v string) error {
-	attrs, err := primitives.AttributesUnmarshal(v)
+	var attrs primitives.Attributes
+	err := attrs.Unmarshal(v)
 	if err != nil {
 		return err
 	}
 
 	for key, val := range attrs {
 		if key == "PART-TARGET" {
-			tmp, err := primitives.DurationUnmarshal(val)
+			var d primitives.Duration
+			err := d.Unmarshal(val)
 			if err != nil {
 				return err
 			}
-			t.PartTarget = tmp
+			t.PartTarget = time.Duration(d)
 		}
 	}
 
diff --git a/pkg/playlist/media_preload_hint.go b/pkg/playlist/media_preload_hint.go
index bee4015..814e999 100644
--- a/pkg/playlist/media_preload_hint.go
+++ b/pkg/playlist/media_preload_hint.go
@@ -21,7 +21,8 @@ type MediaPreloadHint struct {
 }
 
 func (t *MediaPreloadHint) unmarshal(v string) error {
-	attrs, err := primitives.AttributesUnmarshal(v)
+	var attrs primitives.Attributes
+	err := attrs.Unmarshal(v)
 	if err != nil {
 		return err
 	}
diff --git a/pkg/playlist/media_segment.go b/pkg/playlist/media_segment.go
index 0de36b3..6661d68 100644
--- a/pkg/playlist/media_segment.go
+++ b/pkg/playlist/media_segment.go
@@ -79,7 +79,10 @@ func (s MediaSegment) marshal() string {
 	ret += "#EXTINF:" + strconv.FormatFloat(s.Duration.Seconds(), 'f', 5, 64) + "," + s.Title + "\n"
 
 	if s.ByteRangeLength != nil {
-		ret += "#EXT-X-BYTERANGE:" + primitives.ByteRangeMarshal(*s.ByteRangeLength, s.ByteRangeStart) + "\n"
+		ret += "#EXT-X-BYTERANGE:" + primitives.ByteRange{
+			Length: *s.ByteRangeLength,
+			Start:  s.ByteRangeStart,
+		}.Marshal() + "\n"
 	}
 
 	ret += s.URI + "\n"
diff --git a/pkg/playlist/media_server_control.go b/pkg/playlist/media_server_control.go
index 7233114..2ea78a5 100644
--- a/pkg/playlist/media_server_control.go
+++ b/pkg/playlist/media_server_control.go
@@ -30,7 +30,8 @@ type MediaServerControl struct {
 }
 
 func (t *MediaServerControl) unmarshal(v string) error {
-	attrs, err := primitives.AttributesUnmarshal(v)
+	var attrs primitives.Attributes
+	err := attrs.Unmarshal(v)
 	if err != nil {
 		return err
 	}
@@ -41,17 +42,21 @@ func (t *MediaServerControl) unmarshal(v string) error {
 			t.CanBlockReload = (val == "YES")
 
 		case "PART-HOLD-BACK":
-			tmp, err := primitives.DurationUnmarshal(val)
+			var d primitives.Duration
+			err := d.Unmarshal(val)
 			if err != nil {
 				return err
 			}
+			tmp := time.Duration(d)
 			t.PartHoldBack = &tmp
 
 		case "CAN-SKIP-UNTIL":
-			tmp, err := primitives.DurationUnmarshal(val)
+			var d primitives.Duration
+			err := d.Unmarshal(val)
 			if err != nil {
 				return err
 			}
+			tmp := time.Duration(d)
 			t.CanSkipUntil = &tmp
 		}
 	}
diff --git a/pkg/playlist/media_skip.go b/pkg/playlist/media_skip.go
index 9ec4ace..636a969 100644
--- a/pkg/playlist/media_skip.go
+++ b/pkg/playlist/media_skip.go
@@ -15,7 +15,8 @@ type MediaSkip struct {
 }
 
 func (t *MediaSkip) unmarshal(v string) error {
-	attrs, err := primitives.AttributesUnmarshal(v)
+	var attrs primitives.Attributes
+	err := attrs.Unmarshal(v)
 	if err != nil {
 		return err
 	}
diff --git a/pkg/playlist/multivariant.go b/pkg/playlist/multivariant.go
index 3aea8e5..4135e78 100644
--- a/pkg/playlist/multivariant.go
+++ b/pkg/playlist/multivariant.go
@@ -34,7 +34,7 @@ func (m Multivariant) isPlaylist() {}
 func (m *Multivariant) Unmarshal(buf []byte) error {
 	s := string(buf)
 
-	s, err := primitives.HeaderUnmarshal(s)
+	s, err := primitives.SkipHeader(s)
 	if err != nil {
 		return err
 	}
diff --git a/pkg/playlist/multivariant_rendition.go b/pkg/playlist/multivariant_rendition.go
index 418b5db..c3f6641 100644
--- a/pkg/playlist/multivariant_rendition.go
+++ b/pkg/playlist/multivariant_rendition.go
@@ -57,7 +57,8 @@ type MultivariantRendition struct {
 }
 
 func (t *MultivariantRendition) unmarshal(v string) error {
-	attrs, err := primitives.AttributesUnmarshal(v)
+	var attrs primitives.Attributes
+	err := attrs.Unmarshal(v)
 	if err != nil {
 		return err
 	}
diff --git a/pkg/playlist/multivariant_start.go b/pkg/playlist/multivariant_start.go
index 8f634d9..ce3a640 100644
--- a/pkg/playlist/multivariant_start.go
+++ b/pkg/playlist/multivariant_start.go
@@ -16,18 +16,20 @@ type MultivariantStart struct {
 }
 
 func (t *MultivariantStart) unmarshal(v string) error {
-	attrs, err := primitives.AttributesUnmarshal(v)
+	var attrs primitives.Attributes
+	err := attrs.Unmarshal(v)
 	if err != nil {
 		return err
 	}
 
 	for key, val := range attrs {
 		if key == "TIME-OFFSET" {
-			tmp, err := primitives.DurationUnmarshal(val)
+			var d primitives.Duration
+			err := d.Unmarshal(val)
 			if err != nil {
 				return err
 			}
-			t.TimeOffset = tmp
+			t.TimeOffset = time.Duration(d)
 		}
 	}
 
diff --git a/pkg/playlist/multivariant_variant.go b/pkg/playlist/multivariant_variant.go
index ff4646e..b8aeba4 100644
--- a/pkg/playlist/multivariant_variant.go
+++ b/pkg/playlist/multivariant_variant.go
@@ -47,7 +47,8 @@ type MultivariantVariant struct {
 func (v *MultivariantVariant) unmarshal(va string) error {
 	lines := strings.Split(va, "\n")
 
-	attrs, err := primitives.AttributesUnmarshal(lines[0])
+	var attrs primitives.Attributes
+	err := attrs.Unmarshal(lines[0])
 	if err != nil {
 		return err
 	}
diff --git a/pkg/playlist/primitives/attributes.go b/pkg/playlist/primitives/attributes.go
index 5bfbfe5..c14b882 100644
--- a/pkg/playlist/primitives/attributes.go
+++ b/pkg/playlist/primitives/attributes.go
@@ -5,9 +5,12 @@ import (
 	"strings"
 )
 
-// AttributesUnmarshal decodes attributes.
-func AttributesUnmarshal(v string) (map[string]string, error) {
-	ret := make(map[string]string)
+// Attributes are playlist attributes.
+type Attributes map[string]string
+
+// Unmarshal decodes attributes.
+func (a *Attributes) Unmarshal(v string) error {
+	*a = make(Attributes)
 
 	for {
 		if len(v) == 0 {
@@ -17,7 +20,7 @@ func AttributesUnmarshal(v string) (map[string]string, error) {
 		// read key
 		i := strings.IndexByte(v, '=')
 		if i < 0 {
-			return nil, fmt.Errorf("key not found")
+			return fmt.Errorf("key not found")
 		}
 		var key string
 		key, v = v[:i], v[i+1:]
@@ -29,14 +32,14 @@ func AttributesUnmarshal(v string) (map[string]string, error) {
 			v = v[1:]
 			i = strings.IndexByte(v, '"')
 			if i < 0 {
-				return nil, fmt.Errorf("value end delimiter not found")
+				return fmt.Errorf("value end delimiter not found")
 			}
 			val, v = v[:i], v[i+1:]
-			ret[key] = val
+			(*a)[key] = val
 
 			if len(v) != 0 {
 				if v[0] != ',' {
-					return nil, fmt.Errorf("delimiter not found")
+					return fmt.Errorf("delimiter not found")
 				}
 				v = v[1:]
 			}
@@ -44,14 +47,14 @@ func AttributesUnmarshal(v string) (map[string]string, error) {
 			i = strings.IndexByte(v, ',')
 			if i >= 0 {
 				val, v = v[:i], v[i+1:]
-				ret[key] = val
+				(*a)[key] = val
 			} else {
 				val = v
-				ret[key] = val
+				(*a)[key] = val
 				break
 			}
 		}
 	}
 
-	return ret, nil
+	return nil
 }
diff --git a/pkg/playlist/primitives/byterange.go b/pkg/playlist/primitives/byterange.go
index e848c08..2dcbe65 100644
--- a/pkg/playlist/primitives/byterange.go
+++ b/pkg/playlist/primitives/byterange.go
@@ -5,40 +5,50 @@ import (
 	"strings"
 )
 
-// ByteRangeUnmarshal decodes a byte range.
-func ByteRangeUnmarshal(v string) (uint64, *uint64, error) {
+// ByteRange is a byte range.
+type ByteRange struct {
+	Length uint64
+	Start  *uint64
+}
+
+// Unmarshal decodes a byte range.
+func (b *ByteRange) Unmarshal(v string) error {
 	i := strings.IndexByte(v, '@')
 
 	if i >= 0 {
 		str1, str2 := v[:i], v[i+1:]
 
-		length, err := strconv.ParseUint(str1, 10, 64)
+		var err error
+		b.Length, err = strconv.ParseUint(str1, 10, 64)
 		if err != nil {
-			return 0, nil, err
+			return err
 		}
 
 		start, err := strconv.ParseUint(str2, 10, 64)
 		if err != nil {
-			return 0, nil, err
+			return err
 		}
 
-		return length, &start, nil
+		b.Start = &start
+
+		return nil
 	}
 
-	length, err := strconv.ParseUint(v, 10, 64)
+	var err error
+	b.Length, err = strconv.ParseUint(v, 10, 64)
 	if err != nil {
-		return 0, nil, err
+		return err
 	}
 
-	return length, nil, nil
+	return nil
 }
 
-// ByteRangeMarshal encodes a byte range.
-func ByteRangeMarshal(length uint64, start *uint64) string {
-	ret := strconv.FormatUint(length, 10)
+// Marshal encodes a byte range.
+func (b ByteRange) Marshal() string {
+	ret := strconv.FormatUint(b.Length, 10)
 
-	if start != nil {
-		ret += "@" + strconv.FormatUint(*start, 10)
+	if b.Start != nil {
+		ret += "@" + strconv.FormatUint(*b.Start, 10)
 	}
 
 	return ret
diff --git a/pkg/playlist/primitives/duration.go b/pkg/playlist/primitives/duration.go
index 9fd0a23..62b201e 100644
--- a/pkg/playlist/primitives/duration.go
+++ b/pkg/playlist/primitives/duration.go
@@ -5,12 +5,16 @@ import (
 	"time"
 )
 
-// DurationUnmarshal decodes a duration.
-func DurationUnmarshal(val string) (time.Duration, error) {
+// Duration is a playlist duration.
+type Duration time.Duration
+
+// Unmarshal decodes a duration.
+func (d *Duration) Unmarshal(val string) error {
 	tmp, err := strconv.ParseFloat(val, 64)
 	if err != nil {
-		return 0, err
+		return err
 	}
 
-	return time.Duration(tmp * float64(time.Second)), nil
+	*d = Duration(time.Duration(tmp * float64(time.Second)))
+	return nil
 }
diff --git a/pkg/playlist/primitives/header.go b/pkg/playlist/primitives/header.go
index d1c1b1c..7b03e3e 100644
--- a/pkg/playlist/primitives/header.go
+++ b/pkg/playlist/primitives/header.go
@@ -4,14 +4,13 @@ import (
 	"fmt"
 )
 
-// HeaderUnmarshal decodes a header.
-func HeaderUnmarshal(s string) (string, error) {
+// SkipHeader reads and skips a playlist header.
+func SkipHeader(s string) (string, error) {
 	var line string
 	line, s = ReadLine(s)
 
 	if line != "#EXTM3U" {
 		return "", fmt.Errorf("M3U8 header is missing")
 	}
-
 	return s, nil
 }