package xyz.driver.core.file
import akka.NotUsed
import akka.stream.scaladsl.Source
import akka.util.ByteString
import com.google.cloud.ReadChannel
import java.io.{BufferedOutputStream, File, FileInputStream, FileOutputStream}
import java.net.URL
import java.nio.ByteBuffer
import java.nio.file.{Path, Paths}
import java.util.concurrent.TimeUnit
import com.google.cloud.storage.Storage.BlobListOption
import com.google.cloud.storage.{Option => _, _}
import xyz.driver.core.time.Time
import xyz.driver.core.{Name, Revision, generators}
import scala.collection.JavaConverters._
import scala.concurrent.duration.Duration
import scala.concurrent.{ExecutionContext, Future}
import scalaz.{ListT, OptionT}
class GcsStorage(
storageClient: Storage,
bucketName: Name[Bucket],
executionContext: ExecutionContext,
chunkSize: Int = 4096)
extends SignedFileStorage {
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 `$tempDestinationFile`")
} else {
val target = new BufferedOutputStream(new FileOutputStream(tempDestinationFile))
try target.write(blob.getContent())
finally target.close()
tempDestinationFile
}
}
})
}
override def stream(filePath: Path): OptionT[Future, Source[ByteString, NotUsed]] =
OptionT.optionT(Future {
def readChunk(rc: ReadChannel): Option[ByteString] = {
val buffer = ByteBuffer.allocate(chunkSize)
val length = rc.read(buffer)
if (length > 0) {
buffer.flip()
Some(ByteString.fromByteBuffer(buffer))
} else {
None
}
}
Option(storageClient.get(bucketName.value, filePath.toString)).map { blob =>
Source.unfoldResource[ByteString, ReadChannel](
create = () => blob.reader(),
read = channel => readChunk(channel),
close = channel => channel.close()
)
}
})
override def delete(filePath: Path): Future[Unit] = Future {
storageClient.delete(BlobId.of(bucketName.value, filePath.toString))
}
override def list(directoryPath: Path): ListT[Future, FileLink] =
ListT.listT(Future {
val directory = s"$directoryPath/"
val page = storageClient.list(
bucketName.value,
BlobListOption.currentDirectory(),
BlobListOption.prefix(directory)
)
page
.iterateAll()
.asScala
.filter(_.getName != directory)
.map(blobToFileLink(directoryPath, _))
.toList
})
protected def blobToFileLink(path: Path, blob: Blob): FileLink = {
def nullError(property: String) = throw new IllegalStateException(s"Blob $blob at $path does not have $property")
val name = Option(blob.getName).getOrElse(nullError("a name"))
val generation = Option(blob.getGeneration).getOrElse(nullError("a generation"))
val updateTime = Option(blob.getUpdateTime).getOrElse(nullError("an update time"))
val size = Option(blob.getSize).getOrElse(nullError("a size"))
FileLink(
Name(name.split('/').last),
Paths.get(name),
Revision(generation.toString),
Time(updateTime),
size
)
}
override def exists(path: Path): Future[Boolean] = Future {
val blob = Option(
storageClient.get(
bucketName.value,
path.toString
))
blob.isDefined
}
override def signedFileUrl(filePath: Path, duration: Duration): OptionT[Future, URL] =
OptionT.optionT(Future {
Option(storageClient.get(bucketName.value, filePath.toString)).filterNot(_.getSize == 0).map { blob =>
blob.signUrl(duration.toSeconds, TimeUnit.SECONDS)
}
})
}