faster chapter extraction

The extraction of chapters is now faster since it is run in parallel for each pattern. Also a new pattern hast been added: "(start) title"
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Toni Förster 2024-05-19 17:43:35 +02:00
parent 90777d91f6
commit c9fb41c8e8
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@ -152,58 +152,94 @@ extension VideosAPI {
/*
The following chapter patterns are covered:
start - end - title / start - end: Title / start - end title
start - title / start: title / start title / [start] - title / [start]: title / [start] title
index. title - start / index. title start
title: (start)
1) "start - end - title" / "start - end: Title" / "start - end title"
2) "start - title" / "start: title" / "start title" / "[start] - title" / "[start]: title" / "[start] title"
3) "index. title - start" / "index. title start"
4) "title: (start)"
5) "(start) title"
The order is important!
These represent:
- "start" and "end" are timestamps, defining the start and end of the individual chapter
- "title" is the name of the chapter
- "index" is the chapter's position in a list
The order of these patterns is important as it determines the priority. The patterns listed first have a higher priority.
In the case of multiple matches, the pattern with the highest priority will be chosen - lower number means higher priority.
*/
let patterns = [
"(?<=\\n|^)\\s*(?:►\\s*)?\\[?(?<start>(?:[0-9]+:){1,2}[0-9]+)\\]?(?:\\s*-\\s*)?(?<end>(?:[0-9]+:){1,2}[0-9]+)?(?:\\s*-\\s*|\\s*[:]\\s*)?(?<title>.*)(?=\\n|$)",
"(?<=\\n|^)\\s*(?:►\\s*)?\\[?(?<start>(?:[0-9]+:){1,2}[0-9]+)\\]?\\s*[-:]?\\s*(?<title>.+)(?=\\n|$)",
"(?<=\\n|^)(?<index>[0-9]+\\.\\s)(?<title>.+?)(?:\\s*-\\s*)?(?<start>(?:[0-9]+:){1,2}[0-9]+)(?=\\n|$)",
"(?<=\\n|^)(?<title>.+?):\\s*\\((?<start>(?:[0-9]+:){1,2}[0-9]+)\\)(?=\\n|$)"
"(?<=\\n|^)(?<title>.+?):\\s*\\((?<start>(?:[0-9]+:){1,2}[0-9]+)\\)(?=\\n|$)",
"(?<=^|\\n)\\((?<start>(?:[0-9]+:){1,2}[0-9]+)\\)\\s*(?<title>.+?)(?=\\n|$)"
]
for pattern in patterns {
guard let chaptersRegularExpression = try? NSRegularExpression(pattern: pattern, options: .caseInsensitive) else { continue }
let chapterLines = chaptersRegularExpression.matches(in: description, range: NSRange(description.startIndex..., in: description))
let extractChaptersGroup = DispatchGroup()
var capturedChapters: [Int: [Chapter]] = [:]
let lock = NSLock()
if !chapterLines.isEmpty {
return chapterLines.compactMap { line in
let titleRange = line.range(withName: "title")
let startRange = line.range(withName: "start")
guard let titleSubstringRange = Range(titleRange, in: description),
let startSubstringRange = Range(startRange, in: description)
else {
return nil
}
let titleCapture = String(description[titleSubstringRange]).trimmingCharacters(in: .whitespaces)
let startCapture = String(description[startSubstringRange])
let startComponents = startCapture.components(separatedBy: ":")
guard startComponents.count <= 3 else { return nil }
for (index, pattern) in patterns.enumerated() {
extractChaptersGroup.enter()
DispatchQueue.global().async {
if let chaptersRegularExpression = try? NSRegularExpression(pattern: pattern, options: .caseInsensitive) {
let chapterLines = chaptersRegularExpression.matches(in: description, range: NSRange(description.startIndex..., in: description))
let extractedChapters = chapterLines.compactMap { line -> Chapter? in
let titleRange = line.range(withName: "title")
let startRange = line.range(withName: "start")
var hours: Double?
var minutes: Double?
var seconds: Double?
guard let titleSubstringRange = Range(titleRange, in: description),
let startSubstringRange = Range(startRange, in: description)
else {
return nil
}
if startComponents.count == 3 {
hours = Double(startComponents[0])
minutes = Double(startComponents[1])
seconds = Double(startComponents[2])
} else if startComponents.count == 2 {
minutes = Double(startComponents[0])
seconds = Double(startComponents[1])
let titleCapture = String(description[titleSubstringRange]).trimmingCharacters(in: .whitespaces)
let startCapture = String(description[startSubstringRange])
let startComponents = startCapture.components(separatedBy: ":")
guard startComponents.count <= 3 else { return nil }
var hours: Double?
var minutes: Double?
var seconds: Double?
if startComponents.count == 3 {
hours = Double(startComponents[0])
minutes = Double(startComponents[1])
seconds = Double(startComponents[2])
} else if startComponents.count == 2 {
minutes = Double(startComponents[0])
seconds = Double(startComponents[1])
}
guard var startSeconds = seconds else { return nil }
startSeconds += (minutes ?? 0) * 60
startSeconds += (hours ?? 0) * 60 * 60
return Chapter(title: titleCapture, start: startSeconds)
}
guard var startSeconds = seconds else { return nil }
startSeconds += (minutes ?? 0) * 60
startSeconds += (hours ?? 0) * 60 * 60
return .init(title: titleCapture, start: startSeconds)
if !extractedChapters.isEmpty {
lock.lock()
capturedChapters[index] = extractedChapters
lock.unlock()
}
}
extractChaptersGroup.leave()
}
}
extractChaptersGroup.wait()
// Now we sort the keys of the capturedChapters dictionary.
// These keys correspond to the priority of each pattern.
let sortedKeys = Array(capturedChapters.keys).sorted(by: <)
// Return first non-empty result in the order of patterns
for key in sortedKeys {
if let chapters = capturedChapters[key], !chapters.isEmpty {
return chapters
}
}
return []