scala.scalanative.io.VirtualDirectory.scala Maven / Gradle / Ivy
package scala.scalanative
package io
import java.io.Writer
import java.net.URI
import java.nio.ByteBuffer
import java.nio.file._
import java.nio.channels._
import java.util.HashMap
import scalanative.util.{Scope, acquire, defer}
sealed trait VirtualDirectory {
/** A unique identifier for this directory */
def uri: URI
/** Check if file with given path is in the directory. */
def contains(path: Path): Boolean =
files.contains(path)
/** Reads a contents of file with given path. */
def read(path: Path): ByteBuffer
/** Reads up to len bytes from the file with the given path. */
def read(path: Path, len: Int): ByteBuffer
/** Replaces contents of file with given value. */
def write(path: Path, buffer: ByteBuffer): Unit
/** Replaces contents of file using given writer. */
def write(path: Path)(fn: Writer => Unit): Path
/** List all files in this directory. */
def files: Seq[Path]
/** Merges content of source paths into single file in target */
def merge(sources: Seq[Path], target: Path): Unit
}
object VirtualDirectory {
/** Real, non-virtual directory on local file system. */
def local(file: Path): VirtualDirectory = {
def absolute = file.toAbsolutePath
assert(Files.exists(file), s"Local directory doesn't exist: $absolute")
assert(Files.isDirectory(file), s"Not a directory: $absolute")
new LocalDirectory(file)
}
/** Virtual directory that represents contents of the jar file. */
def jar(file: Path)(implicit in: Scope): VirtualDirectory = {
val absolute = file.toAbsolutePath
assert(Files.exists(file), s"Jar doesn't exist: $absolute")
assert(absolute.toString.endsWith(".jar"), s"Not a jar: $absolute")
new JarDirectory(file)
}
/** Virtual directory based on either local directory or a jar. */
def real(file: Path)(implicit in: Scope): VirtualDirectory =
if (Files.isDirectory(file)) {
local(file)
} else if (file.toString.endsWith(".jar")) {
jar(file)
} else {
throw new UnsupportedOperationException(
"Neither a jar, nor a directory: " + file
)
}
/** Empty directory that contains no files. */
val empty: VirtualDirectory = EmptyDirectory
private trait NioDirectory extends VirtualDirectory {
protected def resolve(path: Path): Path = path
protected def open(path: Path) =
FileChannel.open(
path,
StandardOpenOption.CREATE,
StandardOpenOption.WRITE,
StandardOpenOption.TRUNCATE_EXISTING
)
override def read(path: Path): ByteBuffer = {
val bytes = Files.readAllBytes(resolve(path))
val buffer = ByteBuffer.wrap(bytes)
buffer
}
override def read(path: Path, len: Int): ByteBuffer = {
val stream = Files.newInputStream(resolve(path))
try {
val bytes = new Array[Byte](len)
val read = stream.read(bytes)
ByteBuffer.wrap(bytes, 0, read)
} finally stream.close()
}
override def write(path: Path)(fn: Writer => Unit): Path = {
val fullPath = resolve(path)
val writer = Files.newBufferedWriter(fullPath)
try fn(writer)
finally writer.close()
fullPath
}
override def write(path: Path, buffer: ByteBuffer): Unit = {
val channel = open(resolve(path))
try channel.write(buffer)
finally channel.close
}
override def merge(sources: Seq[Path], target: Path): Unit = {
val output = FileChannel.open(
resolve(target),
StandardOpenOption.CREATE,
StandardOpenOption.WRITE,
StandardOpenOption.APPEND
)
try {
sources.foreach { path =>
val input = FileChannel.open(
resolve(path),
StandardOpenOption.READ,
StandardOpenOption.DELETE_ON_CLOSE
)
try {
input.transferTo(0, input.size(), output)
} finally input.close()
}
} finally output.close()
}
}
private final class LocalDirectory(path: Path) extends NioDirectory {
def uri: URI = path.toUri
override protected def resolve(path: Path): Path =
this.path.resolve(path)
override def files: Seq[Path] =
jIteratorToSeq {
Files
.walk(path, Integer.MAX_VALUE, FileVisitOption.FOLLOW_LINKS)
.iterator()
}.map(fp => path.relativize(fp))
}
private final class JarDirectory(path: Path)(implicit in: Scope)
extends NioDirectory {
def uri: URI = URI.create(s"jar:${path.toUri}")
private val fileSystem: FileSystem =
acquire {
try {
val params = new HashMap[String, String]()
params.put("create", "false")
FileSystems.newFileSystem(uri, params)
} catch {
case e: FileSystemAlreadyExistsException =>
FileSystems.getFileSystem(uri)
}
}
override def files: Seq[Path] = {
val roots = jIteratorToSeq(fileSystem.getRootDirectories.iterator())
roots
.flatMap { path =>
jIteratorToSeq {
Files
.walk(path, Integer.MAX_VALUE, FileVisitOption.FOLLOW_LINKS)
.iterator()
}
}
}
}
private object EmptyDirectory extends VirtualDirectory {
val uri: URI = URI.create("")
override def files = Seq.empty
override def read(path: Path): ByteBuffer =
throw new UnsupportedOperationException(
"Can't read from empty directory."
)
override def read(path: Path, len: Int): ByteBuffer = read(path)
override def write(path: Path)(fn: Writer => Unit): Path =
throw new UnsupportedOperationException("Can't write to empty directory.")
override def write(path: Path, buffer: ByteBuffer): Unit =
throw new UnsupportedOperationException("Can't write to empty directory.")
override def merge(sources: Seq[Path], target: Path): Unit =
throw new UnsupportedOperationException("Can't merge in empty directory.")
}
}
© 2015 - 2024 Weber Informatics LLC | Privacy Policy