streamer service: split to separate files

src/Streamer/StreamerService/streamer.service.ts

@@ -0,0 +1,55 @@
+import { ReadStreamCreatable } from '../Interface/read-stream-creatable.interface';
+import { RequestRangeService } from '../RequestRange/request-range.service';
+import { MimeService } from '../Mime/mime.service';
+import { Injectable } from '@nestjs/common';
+import { Request, Response } from 'express';
+import { ResponseHeadersService } from '../ResponseHeadersService/response-headers.service';
+import { ResponseSenderService } from '../ResponseSender/response-sender.service';
+import RequestRangeBytes from '../RequestRange/request-range-bytes.class';
+
+@Injectable()
+export class StreamerService {
+  constructor(
+    private readonly mimeService: MimeService,
+    private readonly requestRangeService: RequestRangeService,
+    private readonly responseHeadersService: ResponseHeadersService,
+    private readonly responseSender: ResponseSenderService,
+  ) {}
+  stream(
+    req: Request,
+    res: Response,
+    streamCreatable: ReadStreamCreatable,
+  ): void {
+    const size = streamCreatable.length;
+    const requestRange = this.getRange(req, size);
+
+    if (!this.requestRangeService.isRangeSatisfiable(requestRange, size)) {
+      return this.handleUnsatisfiable(size, res);
+    }
+
+    const responseHeaders = this.responseHeadersService.createResponseHeaders(
+      streamCreatable.mimeType,
+      size,
+      requestRange,
+    );
+
+    const status = req.headers.range ? 206 : 200;
+    const readable =
+      req.method === 'HEAD'
+        ? null
+        : streamCreatable.createReadStream(requestRange);
+
+    return this.responseSender.send(res, status, responseHeaders, readable);
+  }
+
+  private getRange(req: Request, size: number): RequestRangeBytes {
+    return this.requestRangeService.getRangeFromHeaders(req, size);
+  }
+
+  private handleUnsatisfiable(size: number, res: Response) {
+    const responseHeaders = { 'Content-Range': 'bytes */' + size };
+    this.responseSender.send(res, 416, responseHeaders, null);
+
+    return;
+  }
+}