bypass range cache for mkv playback

.beads/interactions.jsonl

@@ -47,3 +47,4 @@
 {"id":"int-56a87fde","kind":"field_change","created_at":"2026-05-26T04:35:35.693504Z","actor":"dirtydishes","issue_id":"dreamio-3pn","extra":{"field":"status","new_value":"closed","old_value":"in_progress","reason":"Implemented backward-biased seek priming, global 1 MB range-cache chunk alignment, bounded protected eviction, partial foreground miss fetching/logging, main-actor VLC delegate handling, tests, and turn documentation."}}
 {"id":"int-91b3db21","kind":"field_change","created_at":"2026-05-26T04:40:10.299245Z","actor":"dirtydishes","issue_id":"dreamio-mi1","extra":{"field":"status","new_value":"closed","old_value":"in_progress","reason":"Used actual foreground VLC reads as prefetch follow signals on hits and changed foreground misses to fetch aligned chunks; added regression tests and updated the turn document."}}
 {"id":"int-ff0aeb09","kind":"field_change","created_at":"2026-05-26T04:47:44.48931Z","actor":"dirtydishes","issue_id":"dreamio-2hw","extra":{"field":"status","new_value":"closed","old_value":"in_progress","reason":"Fixed stale local range-cache prefetch state after cached seek reads and documented the validation."}}
+{"id":"int-204223f5","kind":"field_change","created_at":"2026-05-26T04:56:13.920284Z","actor":"dirtydishes","issue_id":"dreamio-816","extra":{"field":"status","new_value":"closed","old_value":"in_progress","reason":"Bypassed the local range cache for Matroska-family tail-index containers and added a regression test confirming MKV probes fall back to direct VLC playback without issuing cache probe requests."}}

.beads/issues.jsonl

@@ -1,5 +1,6 @@
 {"_type":"issue","id":"dreamio-mun","title":"fix vlc cache loopback port startup","description":"Device logs showed local-cache playback opening http://127.0.0.1:0, because the NWListener ephemeral port was read before the listener reached ready. Wait for the real assigned port before returning the local cache URL.","status":"closed","priority":0,"issue_type":"bug","assignee":"dirtydishes","owner":"dishes@dpdrm.com","created_at":"2026-05-25T22:32:41Z","created_by":"dirtydishes","updated_at":"2026-05-25T22:33:15Z","started_at":"2026-05-25T22:33:14Z","closed_at":"2026-05-25T22:33:15Z","close_reason":"Wait for NWListener ready state before returning the local cache URL; verified tests and simulator build.","dependency_count":0,"dependent_count":0,"comment_count":0}
 {"_type":"issue","id":"dreamio-8cz","title":"fix stremio external subtitle loading regression","description":"After adding late subtitle forwarding for native playback, Stremio external subtitle loading is failing. Investigate the injected bridge and native subtitle forwarding path, then adjust behavior so Stremio can still load external subtitles while native playback receives late candidates.","status":"closed","priority":0,"issue_type":"bug","assignee":"dirtydishes","owner":"dishes@dpdrm.com","created_at":"2026-05-25T11:05:42Z","created_by":"dirtydishes","updated_at":"2026-05-25T11:07:35Z","started_at":"2026-05-25T11:05:55Z","closed_at":"2026-05-25T11:07:35Z","close_reason":"Hardened subtitle bridge network observers so non-text Stremio subtitle loads are not touched, and made parser traversal deterministic for metadata preservation.","dependency_count":0,"dependent_count":0,"comment_count":0}
+{"_type":"issue","id":"dreamio-816","title":"Fix local range cache playback buffering","description":"Normal VLC playback can stay in buffering after the local progressive HTTP range cache is enabled. Logs show VLC repeatedly probes header/tail MKV ranges through the loopback server while the cache foreground fetch path serializes 1 MB remote requests. Investigate and adjust the cache path so normal direct-file playback can start reliably.","status":"closed","priority":1,"issue_type":"bug","assignee":"dirtydishes","owner":"dishes@dpdrm.com","created_at":"2026-05-26T04:54:13Z","created_by":"dirtydishes","updated_at":"2026-05-26T04:56:14Z","started_at":"2026-05-26T04:54:17Z","closed_at":"2026-05-26T04:56:14Z","close_reason":"Bypassed the local range cache for Matroska-family tail-index containers and added a regression test confirming MKV probes fall back to direct VLC playback without issuing cache probe requests.","dependency_count":0,"dependent_count":0,"comment_count":0}
 {"_type":"issue","id":"dreamio-2hw","title":"Fix range cache prefetch cursor after cached seek reads","description":"Skipping after the local range cache has warmed can leave prefetch following an older foreground cursor instead of the post-seek cached read position. Update the cache so cached foreground reads can reset the follow cursor and add regression coverage.","status":"closed","priority":1,"issue_type":"bug","assignee":"dirtydishes","owner":"dishes@dpdrm.com","created_at":"2026-05-26T04:45:44Z","created_by":"dirtydishes","updated_at":"2026-05-26T04:47:44Z","started_at":"2026-05-26T04:46:36Z","closed_at":"2026-05-26T04:47:44Z","close_reason":"Fixed stale local range-cache prefetch state after cached seek reads and documented the validation.","dependency_count":0,"dependent_count":0,"comment_count":0}
 {"_type":"issue","id":"dreamio-mi1","title":"adapt vlc prefetch to actual post-seek reads","description":"Use real foreground VLC reads after a seek as a prefetch signal even when they are cache hits, and fetch aligned chunks for partial foreground misses so the cache warms ahead before VLC reaches the edge of retained data.","status":"closed","priority":1,"issue_type":"bug","assignee":"dirtydishes","owner":"dishes@dpdrm.com","created_at":"2026-05-26T04:38:14Z","created_by":"dirtydishes","updated_at":"2026-05-26T04:40:10Z","started_at":"2026-05-26T04:38:16Z","closed_at":"2026-05-26T04:40:10Z","close_reason":"Used actual foreground VLC reads as prefetch follow signals on hits and changed foreground misses to fetch aligned chunks; added regression tests and updated the turn document.","dependency_count":0,"dependent_count":0,"comment_count":0}
 {"_type":"issue","id":"dreamio-3pn","title":"reduce vlc seek buffering with range cache priming","description":"Improve VLC local range cache behavior after seek/jump by priming bytes behind the target, using stable global chunk boundaries, retaining useful cached ranges under a byte budget, and adding tests for the observed post-seek request pattern.","status":"closed","priority":1,"issue_type":"task","assignee":"dirtydishes","owner":"dishes@dpdrm.com","created_at":"2026-05-26T04:31:46Z","created_by":"dirtydishes","updated_at":"2026-05-26T04:35:36Z","started_at":"2026-05-26T04:31:51Z","closed_at":"2026-05-26T04:35:36Z","close_reason":"Implemented backward-biased seek priming, global 1 MB range-cache chunk alignment, bounded protected eviction, partial foreground miss fetching/logging, main-actor VLC delegate handling, tests, and turn documentation.","dependency_count":0,"dependent_count":0,"comment_count":0}

Dreamio/ProgressiveHTTPRangeCache.swift

@@ -272,6 +272,9 @@ final class HTTPRangeRemoteFetcher {
         guard !url.path.lowercased().hasSuffix(".m3u8") else {
             return HTTPRangeProbeResult(isCacheable: false, contentLength: nil, fallbackReason: "hls-playlist")
         }
+        guard !Self.shouldBypassCache(for: url) else {
+            return HTTPRangeProbeResult(isCacheable: false, contentLength: nil, fallbackReason: "tail-index-container")
+        }
 
         if let head = try? await response(for: request(method: "HEAD")),
            (200..<400).contains(head.statusCode) {
@@ -330,6 +333,11 @@ final class HTTPRangeRemoteFetcher {
     private func header(_ name: String, in response: HTTPURLResponse) -> String? {
         response.value(forHTTPHeaderField: name)
     }
+
+    private static func shouldBypassCache(for url: URL) -> Bool {
+        let extensionName = url.pathExtension.lowercased()
+        return ["mkv", "mk3d", "mka", "mks", "webm"].contains(extensionName)
+    }
 }
 
 enum HTTPRangeCacheError: Error {

Tests/StreamResolverTests.swift

@@ -43,6 +43,7 @@ struct StreamResolverTests {
         testRangeCacheForegroundMissFetchesAlignedChunks()
         await testRangeCacheForegroundMissReprioritizesPrefetch()
         await testRangeCacheHitFollowsActualPostSeekReadArea()
+        await testRangeProbeBypassesTailIndexContainers()
         await testRangeProbeFallsBackWhenServerIgnoresRange()
         await testRangeFetcherPreservesHeaders()
         print("StreamResolverTests passed")
@@ -540,6 +541,32 @@ struct StreamResolverTests {
         try? await Task.sleep(nanoseconds: 50_000_000)
     }
 
+    private static func testRangeProbeBypassesTailIndexContainers() async {
+        var requestCount = 0
+        MockURLProtocol.handler = { request in
+            requestCount += 1
+            let response = HTTPURLResponse(
+                url: request.url!,
+                statusCode: 206,
+                httpVersion: nil,
+                headerFields: ["Content-Range": "bytes 0-0/20"]
+            )!
+            return (Data([1]), response)
+        }
+
+        let fetcher = HTTPRangeRemoteFetcher(
+            url: URL(string: "https://cdn.example.test/show.mkv?token=secret")!,
+            headers: [:],
+            session: mockSession()
+        )
+        let probe = await fetcher.probe()
+
+        assertEqual(probe.isCacheable, false)
+        assertEqual(probe.fallbackReason, "tail-index-container")
+        assertEqual(requestCount, 0)
+        MockURLProtocol.handler = nil
+    }
+
     private static func byteRange(fromHeader header: String, contentLength: Int64) -> HTTPByteRange {
         let value = header.replacingOccurrences(of: "bytes=", with: "")
         let pieces = value.split(separator: "-", maxSplits: 1).map(String.init)