Merge branch 'ts-segment-caching' into dev

src/routes/m3u8-proxy.ts

@@ -36,6 +36,128 @@ function parseURL(req_url: string, baseUrl?: string) {
   }
 }
 
+interface CacheEntry {
+  data: Uint8Array;
+  headers: Record<string, string>;
+  timestamp: number;
+}
+
+const CACHE_MAX_SIZE = 2000;
+const CACHE_EXPIRY_MS = 2 * 60 * 60 * 1000;
+const segmentCache: Map<string, CacheEntry> = new Map();
+
+function cleanupCache() {
+  const now = Date.now();
+  let expiredCount = 0;
+  
+  for (const [url, entry] of segmentCache.entries()) {
+    if (now - entry.timestamp > CACHE_EXPIRY_MS) {
+      segmentCache.delete(url);
+      expiredCount++;
+    }
+  }
+  
+  if (segmentCache.size > CACHE_MAX_SIZE) {
+    const entries = Array.from(segmentCache.entries())
+      .sort((a, b) => a[1].timestamp - b[1].timestamp);
+    
+    const toRemove = entries.slice(0, segmentCache.size - CACHE_MAX_SIZE);
+    for (const [url] of toRemove) {
+      segmentCache.delete(url);
+    }
+    
+    console.log(`Cache size limit reached. Removed ${toRemove.length} oldest entries. Current size: ${segmentCache.size}`);
+  }
+  
+  if (expiredCount > 0) {
+    console.log(`Cleaned up ${expiredCount} expired cache entries. Current size: ${segmentCache.size}`);
+  }
+  
+  return segmentCache.size;
+}
+
+let cleanupInterval: any = null;
+function startCacheCleanupInterval() {
+  if (!cleanupInterval) {
+    cleanupInterval = setInterval(cleanupCache, 30 * 60 * 1000);
+    console.log('Started periodic cache cleanup interval');
+  }
+}
+
+startCacheCleanupInterval();
+
+async function prefetchSegment(url: string, headers: HeadersInit) {
+  if (segmentCache.size >= CACHE_MAX_SIZE) {
+    cleanupCache();
+  }
+  
+  const existing = segmentCache.get(url);
+  const now = Date.now();
+  if (existing && (now - existing.timestamp <= CACHE_EXPIRY_MS)) {
+    return;
+  }
+  
+  try {
+    const response = await globalThis.fetch(url, {
+      method: 'GET',
+      headers: {
+        'User-Agent': 'Mozilla/5.0 (Windows NT 10.0; Win64; x64; rv:93.0) Gecko/20100101 Firefox/93.0',
+        ...(headers as HeadersInit),
+      }
+    });
+    
+    if (!response.ok) {
+      console.error(`Failed to prefetch TS segment: ${response.status} ${response.statusText}`);
+      return;
+    }
+    
+    const data = new Uint8Array(await response.arrayBuffer());
+    
+    const responseHeaders: Record<string, string> = {};
+    response.headers.forEach((value, key) => {
+      responseHeaders[key] = value;
+    });
+    
+    segmentCache.set(url, { 
+      data, 
+      headers: responseHeaders,
+      timestamp: Date.now()
+    });
+    
+    console.log(`Prefetched and cached segment: ${url}`);
+  } catch (error) {
+    console.error(`Error prefetching segment ${url}:`, error);
+  }
+}
+
+export function getCachedSegment(url: string) {
+  const entry = segmentCache.get(url);
+  if (entry) {
+    if (Date.now() - entry.timestamp > CACHE_EXPIRY_MS) {
+      segmentCache.delete(url);
+      return undefined;
+    }
+    return entry;
+  }
+  return undefined;
+}
+
+export function getCacheStats() {
+  const sizes = Array.from(segmentCache.values())
+    .map(entry => entry.data.byteLength);
+  
+  const totalBytes = sizes.reduce((sum, size) => sum + size, 0);
+  const avgBytes = sizes.length > 0 ? totalBytes / sizes.length : 0;
+  
+  return {
+    entries: segmentCache.size,
+    totalSizeMB: (totalBytes / (1024 * 1024)).toFixed(2),
+    avgEntrySizeKB: (avgBytes / 1024).toFixed(2),
+    maxSize: CACHE_MAX_SIZE,
+    expiryHours: CACHE_EXPIRY_MS / (60 * 60 * 1000)
+  };
+}
+
 /**
  * Proxies m3u8 files and replaces the content to point to the proxy
  */
@@ -139,6 +261,8 @@ async function proxyM3U8(event: any) {
       const lines = m3u8Content.split("\n");
       const newLines: string[] = [];
       
+      const segmentUrls: string[] = [];
+      
       for (const line of lines) {
         if (line.startsWith("#")) {
           if (line.startsWith("#EXT-X-KEY:")) {
@@ -148,6 +272,8 @@ async function proxyM3U8(event: any) {
             if (keyUrl) {
               const proxyKeyUrl = `${baseProxyUrl}/ts-proxy?url=${encodeURIComponent(keyUrl)}&headers=${encodeURIComponent(JSON.stringify(headers))}`;
               newLines.push(line.replace(keyUrl, proxyKeyUrl));
+              
+              prefetchSegment(keyUrl, headers as HeadersInit);
             } else {
               newLines.push(line);
             }
@@ -158,6 +284,8 @@ async function proxyM3U8(event: any) {
           // This is a segment URL (.ts file)
           const segmentUrl = parseURL(line, url);
           if (segmentUrl) {
+            segmentUrls.push(segmentUrl);
+            
             newLines.push(`${baseProxyUrl}/ts-proxy?url=${encodeURIComponent(segmentUrl)}&headers=${encodeURIComponent(JSON.stringify(headers))}`);
           } else {
             newLines.push(line);
@@ -168,6 +296,18 @@ async function proxyM3U8(event: any) {
         }
       }
       
+      if (segmentUrls.length > 0) {
+        console.log(`Starting to prefetch ${segmentUrls.length} segments for ${url}`);
+        
+        cleanupCache();
+        
+        Promise.all(segmentUrls.map(segmentUrl => 
+          prefetchSegment(segmentUrl, headers as HeadersInit)
+        )).catch(error => {
+          console.error('Error prefetching segments:', error);
+        });
+      }
+      
       // Set appropriate headers
       setResponseHeaders(event, {
         'Content-Type': 'application/vnd.apple.mpegurl',
@@ -188,9 +328,22 @@ async function proxyM3U8(event: any) {
   }
 }
 
+export function handleCacheStats(event: any) {
+  cleanupCache();
+  setResponseHeaders(event, {
+    'Content-Type': 'application/json',
+    'Cache-Control': 'no-cache, no-store, must-revalidate'
+  });
+  return getCacheStats();
+}
+
 export default defineEventHandler(async (event) => {
   // Handle CORS preflight requests
   if (isPreflightRequest(event)) return handleCors(event, {});
   
+  if (event.path === '/cache-stats') {
+    return handleCacheStats(event);
+  }
+  
   return await proxyM3U8(event);
-}); 
+});

src/routes/ts-proxy.ts

@@ -1,4 +1,5 @@
 import { setResponseHeaders } from 'h3';
+import { getCachedSegment } from './m3u8-proxy';
 
 export default defineEventHandler(async (event) => {
   // Handle CORS preflight requests
@@ -25,6 +26,20 @@ export default defineEventHandler(async (event) => {
   }
   
   try {
+    const cachedSegment = getCachedSegment(url);
+    
+    if (cachedSegment) {
+      setResponseHeaders(event, {
+        'Content-Type': cachedSegment.headers['content-type'] || 'video/mp2t',
+        'Access-Control-Allow-Origin': '*',
+        'Access-Control-Allow-Headers': '*',
+        'Access-Control-Allow-Methods': '*',
+        'Cache-Control': 'public, max-age=3600' // Allow caching of TS segments
+      });
+      
+      return cachedSegment.data;
+    }
+    
     const response = await globalThis.fetch(url, {
       method: 'GET',
       headers: {
@@ -38,13 +53,12 @@ export default defineEventHandler(async (event) => {
       throw new Error(`Failed to fetch TS file: ${response.status} ${response.statusText}`);
     }
     
-    // Set appropriate headers for each video segment
     setResponseHeaders(event, {
       'Content-Type': 'video/mp2t',
       'Access-Control-Allow-Origin': '*',
       'Access-Control-Allow-Headers': '*',
       'Access-Control-Allow-Methods': '*',
-      'Cache-Control': 'public, max-age=3600'  // Allow caching of TS segments
+      'Cache-Control': 'public, max-age=3600' // Allow caching of TS segments
     });
     
     // Return the binary data directly
@@ -56,4 +70,4 @@ export default defineEventHandler(async (event) => {
       statusMessage: error.message || 'Error proxying TS file'
     }));
   }
-}); 
+});