Refactor the interface of Downloader

voidcontext · Mar 15, 2020 · 80b0f8b · 80b0f8b
1 parent ac2a8bb
commit 80b0f8b
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Showing 3 changed files with 20 additions and 29 deletions.
diff --git a/examples/src/main/scala/vdx/fetchfile/examples/Main.scala b/examples/src/main/scala/vdx/fetchfile/examples/Main.scala
@@ -14,13 +14,13 @@ object Main extends IOApp {
 
     Blocker[IO].use { blocker =>
       val out = new ByteArrayOutputStream()
-      Downloader[IO].fetch(
-        new URL("http://localhost:8088/100MB.bin"),
-        Resource.fromAutoCloseable(IO.delay(out)),
-        blocker,
-        1024,
-        Progress.consoleProgress[IO]
-      ).as(ExitCode.Success)
+      Downloader[IO](blocker, 1024 * 8, Progress.consoleProgress[IO])
+        .fetch(
+          new URL("http://localhost:8088/100MB.bin"),
+          Resource.fromAutoCloseable(IO.delay(out)),
+
+        )
+        .as(ExitCode.Success)
     }
   }
 }
diff --git a/fetch-file/src/main/scala/vdx/fetchfile/Downloader.scala b/fetch-file/src/main/scala/vdx/fetchfile/Downloader.scala
@@ -10,25 +10,17 @@ import java.net.URL
 import cats.effect.ContextShift
 
 trait Downloader[F[_]] {
-  def fetch(
-    url: URL,
-    out: Resource[F, OutputStream],
-    ec: Blocker,
-    chunkSize: Int,
-    progress: Int => Pipe[F, Byte, Unit] = Progress.noop[F]
-  )(implicit backend: Backend[F]): F[Unit]
+  def fetch(url: URL, out: Resource[F, OutputStream]): F[Unit]
 }
 
 object Downloader {
 
-  def apply[F[_]: Concurrent: ContextShift]: Downloader[F] = new Downloader[F] {
-    def fetch(
-      url: URL,
-      out: Resource[F, OutputStream],
-      ec: Blocker,
-      chunkSize: Int,
-      progress: Int => Pipe[F, Byte, Unit] = Progress.noop
-    )(implicit backend: Backend[F]): F[Unit] = {
+  def apply[F[_]: Concurrent: ContextShift](
+    ec: Blocker,
+    chunkSize: Int,
+    progress: Int => Pipe[F, Byte, Unit] = Progress.noop[F]
+  )(implicit backend: Backend[F]): Downloader[F] = new Downloader[F] {
+    def fetch(url: URL, out: Resource[F, OutputStream]): F[Unit] =
       backend(url).product(out).use {
         case ((inStream, contentLength), outStream) =>
           readInputStream[F](Sync[F].delay(inStream), chunkSize, ec)
@@ -37,6 +29,5 @@ object Downloader {
             .compile
             .drain
       }
-    }
   }
 }
diff --git a/fetch-file/src/test/scala/vdx/fetchfile/DownloaderSpec.scala b/fetch-file/src/test/scala/vdx/fetchfile/DownloaderSpec.scala
@@ -23,35 +23,35 @@ class DownloaderSpec extends AnyFlatSpec with Matchers {
           case (s, _) => IO.delay(s.close())
         }
 
-    val downloader = Downloader[IO]
 
 
     (Blocker[IO].use { blocker =>
       val out = new ByteArrayOutputStream()
+      val downloader = Downloader[IO](
+        blocker,
+        1,
+      )
+
       for {
         _        <- downloader.fetch(
           new URL("http://example.com/test.file"),
           Resource.fromAutoCloseable(IO.delay(out)),
-          blocker,
-          1,
         )
         content  <- IO.delay(out.toString)
       } yield content
     }).unsafeRunSync() should be("http://example.com/test.file")
   }
 
   it should "download the file correctly through the HttpURLConnectionBackend" in {
-    val downloader = Downloader[IO]
 
     val downloadedBytes = (Blocker[IO].use { blocker =>
       implicit val backend = HttpURLConnectionBackend[IO]
+      val downloader = Downloader[IO](blocker, 1024 * 8)
       val out = new ByteArrayOutputStream()
       for {
         _ <- downloader.fetch(
           new URL("http://localhost:8088/100MB.bin"),
           Resource.fromAutoCloseable(IO.delay(out)),
-          blocker,
-          1024 * 64,
         )
         content <- IO.delay(out.toByteArray())
       } yield content