Add GCS file storage implementation

1 files changed, 72 insertions, 0 deletions

diff --git a/src/main/scala/xyz/driver/core/file/GcsStorage.scala b/src/main/scala/xyz/driver/core/file/GcsStorage.scala
new file mode 100644
index 0000000..d0a3dad
--- /dev/null
+++ b/src/main/scala/xyz/driver/core/file/GcsStorage.scala
@@ -0,0 +1,72 @@
+package xyz.driver.core.file
+
+import java.io.{BufferedOutputStream, File, FileInputStream, FileOutputStream}
+import java.nio.file.{Path, Paths}
+
+import com.google.cloud.storage.Storage.BlobListOption
+import com.google.cloud.storage._
+import xyz.driver.core.time.Time
+import xyz.driver.core.{Name, Revision, generators}
+
+import scala.collection.JavaConverters._
+import scala.concurrent.{ExecutionContext, Future}
+import scalaz.{ListT, OptionT}
+
+class GcsStorage(storageClient: Storage, bucketName: Name[Bucket], executionContext: ExecutionContext)
+    extends FileStorage {
+  implicit private val execution: ExecutionContext = executionContext
+
+  override def upload(localSource: File, destination: Path): Future[Unit] = Future {
+    checkSafeFileName(destination) {
+      val blobId = BlobId.of(bucketName.value, destination.toString)
+      def acl    = Bucket.BlobWriteOption.predefinedAcl(Storage.PredefinedAcl.PUBLIC_READ)
+
+      storageClient.get(bucketName.value).create(blobId.getName, new FileInputStream(localSource), acl)
+    }
+  }
+
+  override def download(filePath: Path): OptionT[Future, File] = {
+    OptionT.optionT(Future {
+      Option(storageClient.get(bucketName.value, filePath.toString)).filterNot(_.getSize == 0).map {
+        blob =>
+          val tempDir             = System.getProperty("java.io.tmpdir")
+          val randomFolderName    = generators.nextUuid().toString
+          val tempDestinationFile = new File(Paths.get(tempDir, randomFolderName, filePath.toString).toString)
+
+          if (!tempDestinationFile.getParentFile.mkdirs()) {
+            throw new Exception(s"Failed to create temp directory to download file `$tempDestinationFile`")
+          } else {
+            val target = new BufferedOutputStream(new FileOutputStream(tempDestinationFile))
+            try target.write(blob.getContent())
+            finally target.close()
+            tempDestinationFile
+          }
+      }
+    })
+  }
+
+  override def delete(filePath: Path): Future[Unit] = Future {
+    storageClient.delete(BlobId.of(bucketName.value, filePath.toString))
+  }
+
+  override def list(path: Path): ListT[Future, FileLink] =
+    ListT.listT(Future {
+      val page = storageClient.list(
+        bucketName.value,
+        BlobListOption.currentDirectory(),
+        BlobListOption.prefix(path.toString)
+      )
+
+      page.iterateAll().asScala.map(blobToFileLink(path, _)).toList
+    })
+
+  protected def blobToFileLink(path: Path, blob: Blob): FileLink = {
+    FileLink(
+      Name(blob.getName),
+      Paths.get(path.toString, blob.getName),
+      Revision(blob.getGeneration.toString),
+      Time(blob.getUpdateTime),
+      blob.getSize
+    )
+  }
+}