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"
This commit is contained in:
Toni Förster 2024-05-19 17:43:35 +02:00
parent 90777d91f6
commit c9fb41c8e8
No known key found for this signature in database
GPG Key ID: 292F3E5086C83FC7

View File

@ -152,58 +152,94 @@ extension VideosAPI {
/* /*
The following chapter patterns are covered: The following chapter patterns are covered:
start - end - title / start - end: Title / start - end title 1) "start - end - title" / "start - end: Title" / "start - end title"
start - title / start: title / start title / [start] - title / [start]: title / [start] title 2) "start - title" / "start: title" / "start title" / "[start] - title" / "[start]: title" / "[start] title"
index. title - start / index. title start 3) "index. title - start" / "index. title start"
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 = [ 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|$)", "(?<=\\n|^)\\s*(?:►\\s*)?\\[?(?<start>(?:[0-9]+:){1,2}[0-9]+)\\]?(?:\\s*-\\s*)?(?<end>(?:[0-9]+:){1,2}[0-9]+)?(?:\\s*-\\s*|\\s*[:]\\s*)?(?<title>.*)(?=\\n|$)",
"(?<=\\n|^)\\s*(?:►\\s*)?\\[?(?<start>(?:[0-9]+:){1,2}[0-9]+)\\]?\\s*[-:]?\\s*(?<title>.+)(?=\\n|$)", "(?<=\\n|^)\\s*(?:►\\s*)?\\[?(?<start>(?:[0-9]+:){1,2}[0-9]+)\\]?\\s*[-:]?\\s*(?<title>.+)(?=\\n|$)",
"(?<=\\n|^)(?<index>[0-9]+\\.\\s)(?<title>.+?)(?:\\s*-\\s*)?(?<start>(?:[0-9]+:){1,2}[0-9]+)(?=\\n|$)", "(?<=\\n|^)(?<index>[0-9]+\\.\\s)(?<title>.+?)(?:\\s*-\\s*)?(?<start>(?:[0-9]+:){1,2}[0-9]+)(?=\\n|$)",
"(?<=\\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 { let extractChaptersGroup = DispatchGroup()
guard let chaptersRegularExpression = try? NSRegularExpression(pattern: pattern, options: .caseInsensitive) else { continue } var capturedChapters: [Int: [Chapter]] = [:]
let chapterLines = chaptersRegularExpression.matches(in: description, range: NSRange(description.startIndex..., in: description)) let lock = NSLock()
if !chapterLines.isEmpty { for (index, pattern) in patterns.enumerated() {
return chapterLines.compactMap { line in extractChaptersGroup.enter()
let titleRange = line.range(withName: "title") DispatchQueue.global().async {
let startRange = line.range(withName: "start") if let chaptersRegularExpression = try? NSRegularExpression(pattern: pattern, options: .caseInsensitive) {
guard let titleSubstringRange = Range(titleRange, in: description), let chapterLines = chaptersRegularExpression.matches(in: description, range: NSRange(description.startIndex..., in: description))
let startSubstringRange = Range(startRange, in: description) let extractedChapters = chapterLines.compactMap { line -> Chapter? in
else { let titleRange = line.range(withName: "title")
return nil let startRange = line.range(withName: "start")
}
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? guard let titleSubstringRange = Range(titleRange, in: description),
var minutes: Double? let startSubstringRange = Range(startRange, in: description)
var seconds: Double? else {
return nil
}
if startComponents.count == 3 { let titleCapture = String(description[titleSubstringRange]).trimmingCharacters(in: .whitespaces)
hours = Double(startComponents[0]) let startCapture = String(description[startSubstringRange])
minutes = Double(startComponents[1]) let startComponents = startCapture.components(separatedBy: ":")
seconds = Double(startComponents[2]) guard startComponents.count <= 3 else { return nil }
} else if startComponents.count == 2 {
minutes = Double(startComponents[0]) var hours: Double?
seconds = Double(startComponents[1]) 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 } if !extractedChapters.isEmpty {
lock.lock()
startSeconds += (minutes ?? 0) * 60 capturedChapters[index] = extractedChapters
startSeconds += (hours ?? 0) * 60 * 60 lock.unlock()
}
return .init(title: titleCapture, start: startSeconds)
} }
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 [] return []