feat: spool media inputs to disk and report producer progress (#1520)

internal/protocol/http/fetcher.go

@@ -512,17 +512,9 @@ func (f *Fetcher) asyncPrefetch() {
 		return
 	}
 
-	// Create temporary file for prefetch data
-	tmpFile, err := os.CreateTemp("", "gopeed-prefetch-*")
-	if err != nil {
-		f.prefetchErr = err
-		return
-	}
-	f.prefetchFile = tmpFile
-	f.prefetchFilePath = tmpFile.Name()
-
 	defer func() {
-		// Close response body when prefetch stops
+		// Close the response even if temporary-file setup fails or shutdown
+		// rejects a late prefetch. Otherwise the server can remain blocked writing.
 		f.resolveRespLock.Lock()
 		if f.resolveResp != nil {
 			f.resolveResp.Body.Close()
@@ -531,8 +523,33 @@ func (f *Fetcher) asyncPrefetch() {
 		f.resolveRespLock.Unlock()
 	}()
 
+	// Create temporary file for prefetch data
+	tempDir := ""
+	if f.ctl != nil && f.ctl.TempDir != "" {
+		tempDir = f.ctl.TempDir
+		if err := os.MkdirAll(tempDir, 0700); err != nil {
+			f.prefetchErr = err
+			return
+		}
+	}
+	tmpFile, err := os.CreateTemp(tempDir, "gopeed-prefetch-*")
+	if err != nil {
+		f.prefetchErr = err
+		return
+	}
+	if f.ctl != nil {
+		if err := f.ctl.TempFiles.Track(tmpFile.Name()); err != nil {
+			tmpFile.Close()
+			os.Remove(tmpFile.Name())
+			f.prefetchErr = err
+			return
+		}
+	}
+	f.prefetchFile = tmpFile
+	f.prefetchFilePath = tmpFile.Name()
+
 	buf := make([]byte, 32*1024) // 32KB buffer
-	reader := NewTimeoutReader(resp.Body, readTimeout)
+	reader := f.responseReader(resp)
 
 	for {
 		select {
@@ -617,7 +634,11 @@ func (f *Fetcher) cleanupPrefetchFile() {
 		f.prefetchFile = nil
 	}
 	if f.prefetchFilePath != "" {
-		os.Remove(f.prefetchFilePath)
+		if f.ctl != nil {
+			f.ctl.TempFiles.Remove(f.prefetchFilePath)
+		} else {
+			os.Remove(f.prefetchFilePath)
+		}
 		f.prefetchFilePath = ""
 	}
 	// The byte count is only reusable while the backing prefetch file exists.
@@ -1329,7 +1350,7 @@ func (f *Fetcher) downloadChunkOnce(conn *connection, client *http.Client, buf [
 		f.slowStart.onConnectSuccess()
 	}
 
-	reader := NewTimeoutReader(resp.Body, readTimeout)
+	reader := f.responseReader(resp)
 	var responseBytesRead int64
 	for {
 		if conn.ctx.Err() != nil {
@@ -1711,7 +1732,7 @@ func (f *Fetcher) runConnectionWithResolveResp(conn *connection) {
 	}
 
 	// Download data from resolve response
-	reader := NewTimeoutReader(resp.Body, readTimeout)
+	reader := f.responseReader(resp)
 	for {
 		if conn.ctx.Err() != nil {
 			return
@@ -1828,7 +1849,7 @@ func (f *Fetcher) runConnectionFallback(conn *connection) {
 				f.slowStart.onConnectSuccess()
 			}
 
-			reader := NewTimeoutReader(resp.Body, readTimeout)
+			reader := f.responseReader(resp)
 			for {
 				if conn.ctx.Err() != nil {
 					return conn.ctx.Err()
@@ -2451,3 +2472,12 @@ func (f *Fetcher) Progress() fetcher.Progress {
 func (f *Fetcher) Wait() error {
 	return <-f.doneCh
 }
+
+// Generated output can pause while its producer waits for processing capacity.
+// Its producer owns upstream deadlines; cancellation still closes the response.
+func (f *Fetcher) responseReader(resp *http.Response) io.Reader {
+	if f.ctl != nil && f.ctl.ManagedProduction != nil && resp.Request != nil && f.ctl.ManagedProduction(resp.Request.URL.String()) {
+		return resp.Body
+	}
+	return NewTimeoutReader(resp.Body, readTimeout)
+}