add vlc local range cache

This commit is contained in:
dirtydishes 2026-05-25 18:22:09 -04:00
parent 4815c3a7f6
commit e7a80df7cc
7 changed files with 1029 additions and 18 deletions

View file

@ -0,0 +1,464 @@
import Foundation
import Network
struct HTTPByteRange: Equatable {
let start: Int64
let end: Int64
var length: Int64 {
max(0, end - start + 1)
}
func overlapsOrTouches(_ other: HTTPByteRange) -> Bool {
start <= other.end + 1 && other.start <= end + 1
}
func merged(with other: HTTPByteRange) -> HTTPByteRange {
HTTPByteRange(start: min(start, other.start), end: max(end, other.end))
}
}
struct HTTPContentRange: Equatable {
let range: HTTPByteRange
let totalLength: Int64?
static func parse(_ value: String) -> HTTPContentRange? {
let trimmed = value.trimmingCharacters(in: .whitespacesAndNewlines)
guard trimmed.lowercased().hasPrefix("bytes ") else {
return nil
}
let body = trimmed.dropFirst("bytes ".count)
let pieces = body.split(separator: "/", maxSplits: 1).map(String.init)
guard pieces.count == 2 else {
return nil
}
let rangePieces = pieces[0].split(separator: "-", maxSplits: 1).map(String.init)
guard rangePieces.count == 2,
let start = Int64(rangePieces[0]),
let end = Int64(rangePieces[1]),
start >= 0,
end >= start else {
return nil
}
let total = pieces[1] == "*" ? nil : Int64(pieces[1])
return HTTPContentRange(range: HTTPByteRange(start: start, end: end), totalLength: total)
}
}
struct HTTPRangeProbeResult {
let isCacheable: Bool
let contentLength: Int64?
let fallbackReason: String?
}
final class SparseHTTPByteRangeStore {
private struct Segment {
var range: HTTPByteRange
var data: Data
}
private let lock = NSLock()
private var segments: [Segment] = []
var cachedRanges: [HTTPByteRange] {
lock.withLock {
segments.map(\.range)
}
}
func insert(data: Data, at start: Int64) {
guard !data.isEmpty else {
return
}
let insertedRange = HTTPByteRange(start: start, end: start + Int64(data.count) - 1)
lock.withLock {
segments.append(Segment(range: insertedRange, data: data))
segments.sort { $0.range.start < $1.range.start }
mergeSegments()
}
}
func data(for range: HTTPByteRange) -> Data? {
lock.withLock {
guard let firstIndex = segments.firstIndex(where: { $0.range.start <= range.start && $0.range.end >= range.start }) else {
return nil
}
var cursor = range.start
var result = Data()
for segment in segments[firstIndex...] {
guard segment.range.start <= cursor, segment.range.end >= cursor else {
break
}
let readEnd = min(segment.range.end, range.end)
let lower = Int(cursor - segment.range.start)
let upper = Int(readEnd - segment.range.start + 1)
result.append(segment.data.subdata(in: lower..<upper))
cursor = readEnd + 1
if cursor > range.end {
return result
}
}
return nil
}
}
func hasData(for range: HTTPByteRange) -> Bool {
data(for: range) != nil
}
func evict(keeping window: HTTPByteRange) {
lock.withLock {
segments.removeAll { !$0.range.overlapsOrTouches(window) }
}
}
private func mergeSegments() {
guard !segments.isEmpty else {
return
}
var merged: [Segment] = []
for segment in segments {
guard var previous = merged.popLast() else {
merged.append(segment)
continue
}
guard previous.range.overlapsOrTouches(segment.range) else {
merged.append(previous)
merged.append(segment)
continue
}
if segment.range.end > previous.range.end {
let overlap = max(0, previous.range.end - segment.range.start + 1)
if overlap < Int64(segment.data.count) {
previous.data.append(segment.data.dropFirst(Int(overlap)))
}
previous.range = previous.range.merged(with: segment.range)
}
merged.append(previous)
}
segments = merged
}
}
final class HTTPRangeRemoteFetcher {
let url: URL
let headers: [String: String]
private let session: URLSession
init(url: URL, headers: [String: String], session: URLSession = .shared) {
self.url = url
self.headers = headers
self.session = session
}
func probe() async -> HTTPRangeProbeResult {
guard ["http", "https"].contains(url.scheme?.lowercased() ?? "") else {
return HTTPRangeProbeResult(isCacheable: false, contentLength: nil, fallbackReason: "non-http-url")
}
guard !url.path.lowercased().hasSuffix(".m3u8") else {
return HTTPRangeProbeResult(isCacheable: false, contentLength: nil, fallbackReason: "hls-playlist")
}
if let head = try? await response(for: request(method: "HEAD")),
(200..<400).contains(head.statusCode) {
let acceptsRanges = header("Accept-Ranges", in: head)?.lowercased().contains("bytes") == true
let length = header("Content-Length", in: head).flatMap(Int64.init)
if acceptsRanges, let length, length > 0 {
return HTTPRangeProbeResult(isCacheable: true, contentLength: length, fallbackReason: nil)
}
}
var tinyRequest = request(method: "GET")
tinyRequest.setValue("bytes=0-0", forHTTPHeaderField: "Range")
do {
let (data, response) = try await session.data(for: tinyRequest)
guard let http = response as? HTTPURLResponse else {
return HTTPRangeProbeResult(isCacheable: false, contentLength: nil, fallbackReason: "probe-non-http-response")
}
guard http.statusCode == 206,
let contentRange = header("Content-Range", in: http).flatMap(HTTPContentRange.parse),
data.count <= 1 else {
return HTTPRangeProbeResult(isCacheable: false, contentLength: nil, fallbackReason: "range-probe-status-\(http.statusCode)")
}
return HTTPRangeProbeResult(isCacheable: true, contentLength: contentRange.totalLength, fallbackReason: nil)
} catch {
return HTTPRangeProbeResult(isCacheable: false, contentLength: nil, fallbackReason: "range-probe-error-\(error.localizedDescription)")
}
}
func fetch(range: HTTPByteRange) async throws -> Data {
var rangeRequest = request(method: "GET")
rangeRequest.setValue("bytes=\(range.start)-\(range.end)", forHTTPHeaderField: "Range")
let (data, response) = try await session.data(for: rangeRequest)
guard let http = response as? HTTPURLResponse else {
throw HTTPRangeCacheError.remoteRejectedRange("non-http-response")
}
guard http.statusCode == 206 else {
throw HTTPRangeCacheError.remoteRejectedRange("status-\(http.statusCode)")
}
return data
}
private func response(for request: URLRequest) async throws -> HTTPURLResponse? {
let (_, response) = try await session.data(for: request)
return response as? HTTPURLResponse
}
private func request(method: String) -> URLRequest {
var request = URLRequest(url: url)
request.httpMethod = method
headers.forEach { key, value in
request.setValue(value, forHTTPHeaderField: key)
}
return request
}
private func header(_ name: String, in response: HTTPURLResponse) -> String? {
response.value(forHTTPHeaderField: name)
}
}
enum HTTPRangeCacheError: Error {
case remoteRejectedRange(String)
case serverUnavailable
}
final class ProgressiveHTTPRangeCacheSession {
let id = UUID().uuidString
let store = SparseHTTPByteRangeStore()
let fetcher: HTTPRangeRemoteFetcher
let contentLength: Int64
let durationProvider: () -> TimeInterval
private let prefetchChunkSize: Int64 = 1_048_576
private var prefetchTask: Task<Void, Never>?
init(fetcher: HTTPRangeRemoteFetcher, contentLength: Int64, durationProvider: @escaping () -> TimeInterval) {
self.fetcher = fetcher
self.contentLength = contentLength
self.durationProvider = durationProvider
}
func data(for requestedRange: HTTPByteRange) async throws -> Data {
let bounded = clamp(requestedRange)
if let data = store.data(for: bounded) {
#if DEBUG
print("[DreamioRangeCache] cache=hit range=\(bounded.start)-\(bounded.end)")
#endif
return data
}
#if DEBUG
print("[DreamioRangeCache] cache=miss range=\(bounded.start)-\(bounded.end)")
#endif
let data = try await fetcher.fetch(range: bounded)
store.insert(data: data, at: bounded.start)
prefetch(aroundByteOffset: bounded.end + 1)
return store.data(for: bounded) ?? data
}
func prefetch(aroundByteOffset offset: Int64) {
prefetchTask?.cancel()
let window = targetWindow(aroundByteOffset: offset)
store.evict(keeping: window)
guard !store.hasData(for: window) else {
return
}
prefetchTask = Task { [weak self] in
guard let self else {
return
}
var cursor = window.start
while cursor <= window.end, !Task.isCancelled {
let chunk = HTTPByteRange(start: cursor, end: min(window.end, cursor + prefetchChunkSize - 1))
if !store.hasData(for: chunk) {
do {
let data = try await fetcher.fetch(range: chunk)
store.insert(data: data, at: chunk.start)
#if DEBUG
print("[DreamioRangeCache] fetched range=\(chunk.start)-\(chunk.end) bytes=\(data.count)")
#endif
} catch {
#if DEBUG
print("[DreamioRangeCache] prefetch failed range=\(chunk.start)-\(chunk.end) error=\(error)")
#endif
return
}
}
cursor = chunk.end + 1
}
}
}
func byteOffset(for position: Float) -> Int64 {
let clamped = max(0, min(1, position))
return Int64(Float(contentLength) * clamped)
}
private func targetWindow(aroundByteOffset offset: Int64) -> HTTPByteRange {
let bytesPerSecond = estimatedBytesPerSecond()
let behind = max(prefetchChunkSize, bytesPerSecond * 30)
let ahead = max(prefetchChunkSize * 2, bytesPerSecond * 60)
return clamp(HTTPByteRange(start: offset - behind, end: offset + ahead))
}
private func estimatedBytesPerSecond() -> Int64 {
let duration = durationProvider()
guard duration > 1 else {
return 512_000
}
return max(1, Int64(Double(contentLength) / duration))
}
private func clamp(_ range: HTTPByteRange) -> HTTPByteRange {
HTTPByteRange(
start: max(0, min(contentLength - 1, range.start)),
end: max(0, min(contentLength - 1, range.end))
)
}
}
final class ProgressiveHTTPRangeCacheServer {
static let shared = ProgressiveHTTPRangeCacheServer()
private let queue = DispatchQueue(label: "dreamio.range-cache.server")
private var listener: NWListener?
private var port: UInt16?
private var sessions: [String: ProgressiveHTTPRangeCacheSession] = [:]
func localURL(for session: ProgressiveHTTPRangeCacheSession) throws -> URL {
try startIfNeeded()
sessions[session.id] = session
guard let port,
let url = URL(string: "http://127.0.0.1:\(port)/stream/\(session.id)") else {
throw HTTPRangeCacheError.serverUnavailable
}
return url
}
private func startIfNeeded() throws {
guard listener == nil else {
return
}
let listener = try NWListener(using: .tcp, on: .any)
listener.newConnectionHandler = { [weak self] connection in
self?.handle(connection)
}
listener.start(queue: queue)
self.listener = listener
self.port = listener.port.map { UInt16($0.rawValue) }
}
private func handle(_ connection: NWConnection) {
connection.start(queue: queue)
connection.receive(minimumIncompleteLength: 1, maximumLength: 16_384) { [weak self] data, _, _, _ in
guard let self, let data, let requestText = String(data: data, encoding: .utf8) else {
connection.cancel()
return
}
Task {
await self.respond(to: requestText, on: connection)
}
}
}
private func respond(to requestText: String, on connection: NWConnection) async {
guard let requestLine = requestText.components(separatedBy: "\r\n").first else {
send(status: "400 Bad Request", headers: [:], body: Data(), on: connection)
return
}
let parts = requestLine.split(separator: " ")
guard parts.count >= 2,
parts[0] == "GET",
let path = parts[safe: 1],
path.hasPrefix("/stream/") else {
send(status: "404 Not Found", headers: [:], body: Data(), on: connection)
return
}
let id = String(path.dropFirst("/stream/".count))
guard let session = sessions[id] else {
send(status: "404 Not Found", headers: [:], body: Data(), on: connection)
return
}
let requestedRange = parseRangeHeader(in: requestText, contentLength: session.contentLength)
?? HTTPByteRange(start: 0, end: min(session.contentLength - 1, 1_048_575))
do {
let data = try await session.data(for: requestedRange)
let headers = [
"Accept-Ranges": "bytes",
"Content-Length": "\(data.count)",
"Content-Range": "bytes \(requestedRange.start)-\(requestedRange.end)/\(session.contentLength)",
"Content-Type": "application/octet-stream",
"Connection": "close"
]
send(status: "206 Partial Content", headers: headers, body: data, on: connection)
} catch {
send(status: "502 Bad Gateway", headers: ["Connection": "close"], body: Data(), on: connection)
}
}
private func parseRangeHeader(in request: String, contentLength: Int64) -> HTTPByteRange? {
let lines = request.components(separatedBy: "\r\n")
guard let line = lines.first(where: { $0.lowercased().hasPrefix("range:") }) else {
return nil
}
let value = line.dropFirst("Range:".count).trimmingCharacters(in: .whitespaces)
guard value.lowercased().hasPrefix("bytes=") else {
return nil
}
let rangeValue = value.dropFirst("bytes=".count)
let pieces = rangeValue.split(separator: "-", maxSplits: 1, omittingEmptySubsequences: false)
guard pieces.count == 2,
let start = Int64(pieces[0]) else {
return nil
}
let end = pieces[1].isEmpty ? contentLength - 1 : (Int64(pieces[1]) ?? contentLength - 1)
guard start >= 0, end >= start else {
return nil
}
return HTTPByteRange(start: start, end: min(end, contentLength - 1))
}
private func send(status: String, headers: [String: String], body: Data, on connection: NWConnection) {
var response = "HTTP/1.1 \(status)\r\n"
headers.forEach { key, value in
response += "\(key): \(value)\r\n"
}
response += "\r\n"
var payload = Data(response.utf8)
payload.append(body)
connection.send(content: payload, completion: .contentProcessed { _ in
connection.cancel()
})
}
}
private extension NSLock {
func withLock<T>(_ body: () -> T) -> T {
lock()
defer { unlock() }
return body()
}
}
private extension Array {
subscript(safe index: Index) -> Element? {
indices.contains(index) ? self[index] : nil
}
}

View file

@ -23,6 +23,10 @@ final class VLCNativePlaybackBackend: NSObject, NativePlaybackBackend {
#if canImport(MobileVLCKit)
private let mediaPlayer = VLCMediaPlayer()
#endif
private var rangeCacheSession: ProgressiveHTTPRangeCacheSession?
private var playbackStartupTask: Task<Void, Never>?
private var lastLoggedState: String?
private var lastBufferingLogTime: Date?
private var attachedSubtitleURLs = Set<URL>()
private var didAutoSelectSubtitleTrack = false
private var didUserSelectSubtitleTrack = false
@ -48,6 +52,7 @@ final class VLCNativePlaybackBackend: NSObject, NativePlaybackBackend {
func play(request: NativePlaybackRequest) {
#if canImport(MobileVLCKit)
playbackStartupTask?.cancel()
attachedSubtitleURLs.removeAll()
didAutoSelectSubtitleTrack = false
didUserSelectSubtitleTrack = false
@ -56,23 +61,63 @@ final class VLCNativePlaybackBackend: NSObject, NativePlaybackBackend {
hasPendingExternalSubtitleSelection = false
pendingExternalSubtitleDisplayNames.removeAll()
externalSubtitleDisplayNamesByTrackID.removeAll()
let media = VLCMedia(url: request.playbackURL)
let headerValue = request.headers
.map { "\($0.key): \($0.value)" }
.joined(separator: "\r\n")
media.addOption(":http-referrer=\(request.referer)")
if let userAgent = request.userAgent {
media.addOption(":http-user-agent=\(userAgent)")
}
if !headerValue.isEmpty {
media.addOption(":http-header=\(headerValue)")
}
mediaPlayer.media = media
rangeCacheSession = nil
lastLoggedState = nil
lastBufferingLogTime = nil
#if DEBUG
print("[DreamioVLC] opening url=\(URLRedactor.redactedURLString(request.playbackURL.absoluteString))")
print("[DreamioVLC] cache-probe url=\(URLRedactor.redactedURLString(request.playbackURL.absoluteString))")
#endif
mediaPlayer.play()
playbackStartupTask = Task { [weak self] in
guard let self else {
return
}
let fetcher = HTTPRangeRemoteFetcher(url: request.playbackURL, headers: request.headers)
let probe = await fetcher.probe()
guard !Task.isCancelled else {
return
}
if probe.isCacheable, let contentLength = probe.contentLength, contentLength > 0 {
do {
let session = ProgressiveHTTPRangeCacheSession(
fetcher: fetcher,
contentLength: contentLength,
durationProvider: { [weak self] in self?.duration ?? 0 }
)
let localURL = try ProgressiveHTTPRangeCacheServer.shared.localURL(for: session)
await MainActor.run {
self.rangeCacheSession = session
session.prefetch(aroundByteOffset: 0)
self.startVLCMedia(
url: localURL,
request: request,
playbackMode: "local-cache",
cachingMilliseconds: 500,
includeRemoteHTTPOptions: false
)
}
return
} catch {
#if DEBUG
print("[DreamioVLC] cache fallback reason=local-server-error-\(error)")
#endif
}
} else {
#if DEBUG
print("[DreamioVLC] cache fallback reason=\(probe.fallbackReason ?? "unknown")")
#endif
}
await MainActor.run {
self.startVLCMedia(
url: request.playbackURL,
request: request,
playbackMode: "direct",
cachingMilliseconds: 2500,
includeRemoteHTTPOptions: true
)
}
}
#else
onFailure?(NativePlaybackError.backendUnavailable)
#endif
@ -99,7 +144,16 @@ final class VLCNativePlaybackBackend: NSObject, NativePlaybackBackend {
guard isSeekable else {
return
}
mediaPlayer.position = max(0, min(1, position))
let clamped = max(0, min(1, position))
rangeCacheSession?.prefetch(aroundByteOffset: rangeCacheSession?.byteOffset(for: clamped) ?? 0)
#if DEBUG
if let byteOffset = rangeCacheSession?.byteOffset(for: clamped) {
print("[DreamioVLC] seek targetPosition=\(clamped) byteOffset=\(byteOffset) mode=local-cache")
} else {
print("[DreamioVLC] seek targetPosition=\(clamped) mode=direct")
}
#endif
mediaPlayer.position = clamped
#endif
}
@ -109,6 +163,17 @@ final class VLCNativePlaybackBackend: NSObject, NativePlaybackBackend {
return
}
let nextTime = max(0, min(duration, currentTime + seconds))
if duration > 0 {
let nextPosition = Float(nextTime / duration)
rangeCacheSession?.prefetch(aroundByteOffset: rangeCacheSession?.byteOffset(for: nextPosition) ?? 0)
#if DEBUG
if let byteOffset = rangeCacheSession?.byteOffset(for: nextPosition) {
print("[DreamioVLC] jump seconds=\(seconds) target=\(nextTime) byteOffset=\(byteOffset) mode=local-cache")
} else {
print("[DreamioVLC] jump seconds=\(seconds) target=\(nextTime) mode=direct")
}
#endif
}
mediaPlayer.time = VLCTime(int: Int32(nextTime * 1000))
#endif
}
@ -165,6 +230,8 @@ final class VLCNativePlaybackBackend: NSObject, NativePlaybackBackend {
func stop() {
#if canImport(MobileVLCKit)
playbackStartupTask?.cancel()
rangeCacheSession = nil
mediaPlayer.stop()
mediaPlayer.drawable = nil
mediaPlayer.media = nil
@ -269,6 +336,40 @@ final class VLCNativePlaybackBackend: NSObject, NativePlaybackBackend {
}
#if canImport(MobileVLCKit)
private func startVLCMedia(
url: URL,
request: NativePlaybackRequest,
playbackMode: String,
cachingMilliseconds: Int,
includeRemoteHTTPOptions: Bool
) {
let media = VLCMedia(url: url)
media.addOption(":network-caching=\(cachingMilliseconds)")
if includeRemoteHTTPOptions {
media.addOption(":http-reconnect")
addRemoteHeaders(to: media, request: request)
}
mediaPlayer.media = media
#if DEBUG
print("[DreamioVLC] opening mode=\(playbackMode) cachingMs=\(cachingMilliseconds) url=\(URLRedactor.redactedURLString(url.absoluteString))")
#endif
mediaPlayer.play()
}
private func addRemoteHeaders(to media: VLCMedia, request: NativePlaybackRequest) {
let headerValue = request.headers
.map { "\($0.key): \($0.value)" }
.joined(separator: "\r\n")
media.addOption(":http-referrer=\(request.referer)")
if let userAgent = request.userAgent {
media.addOption(":http-user-agent=\(userAgent)")
}
if !headerValue.isEmpty {
media.addOption(":http-header=\(headerValue)")
}
}
private func attachSubtitles(_ candidates: [SubtitleCandidate]) -> Int {
var attachedCount = 0
var duplicateCount = 0
@ -430,7 +531,7 @@ final class VLCNativePlaybackBackend: NSObject, NativePlaybackBackend {
extension VLCNativePlaybackBackend: VLCMediaPlayerDelegate {
func mediaPlayerStateChanged(_ aNotification: Notification) {
#if DEBUG
print("[DreamioVLC] state=\(stateName(mediaPlayer.state))")
logPlaybackStateIfNeeded(stateName(mediaPlayer.state))
#endif
switch mediaPlayer.state {
case .buffering, .playing:
@ -477,5 +578,24 @@ extension VLCNativePlaybackBackend: VLCMediaPlayerDelegate {
return "unknown"
}
}
#if DEBUG
private func logPlaybackStateIfNeeded(_ state: String) {
if state == "buffering" {
let now = Date()
if lastLoggedState == state,
let lastBufferingLogTime,
now.timeIntervalSince(lastBufferingLogTime) < 2 {
return
}
lastBufferingLogTime = now
}
if lastLoggedState != state || state == "buffering" {
print("[DreamioVLC] state=\(state)")
lastLoggedState = state
}
}
#endif
}
#endif