jetbrains.exodus.vfs.Cluster.kt Maven / Gradle / Ivy
/**
* Copyright 2010 - 2022 JetBrains s.r.o.
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* https://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
package jetbrains.exodus.vfs
import jetbrains.exodus.*
import jetbrains.exodus.ByteIterator
import jetbrains.exodus.bindings.IntegerBinding
import jetbrains.exodus.log.BlockByteIterator
import jetbrains.exodus.util.LightOutputStream
import java.io.File
import java.io.IOException
import java.io.RandomAccessFile
internal class Cluster(private val it: ByteIterable) : Iterator {
private var iterator: ByteIterator? = null
var startingPosition: Long = 0
var clusterNumber: Long = 0
private var size: Int = 0
fun getSize() = getIterator().run { size }
override fun hasNext() = getSize() > 0
override fun next() = getIterator().next().also { --size }
fun nextBytes(array: ByteArray, off: Int, len: Int): Int {
val iterator = getIterator()
if (iterator is BlockByteIterator) {
return iterator.nextBytes(array, off, len).also { readBytes -> size -= readBytes }
}
val result = kotlin.math.min(len, size)
for (i in 0 until result) {
array[off + i] = iterator.next()
}
size -= result
return result
}
fun skip(length: Long): Long {
val size = getSize()
val skipped = if (length > size) size.toLong() else getIterator().skip(length)
this.size -= skipped.toInt()
return skipped
}
fun copyTo(array: ByteArray) {
var i = 0
while (hasNext()) {
array[i++] = next()
}
}
private fun getIterator(): ByteIterator {
return iterator ?: it.iterator().apply {
iterator = this
size = IntegerBinding.readCompressed(this)
}
}
companion object {
@JvmStatic
fun writeCluster(cluster: ByteArray,
clusterConverter: ClusterConverter?,
size: Int,
accumulateInRAM: Boolean): ByteIterable {
if (accumulateInRAM) {
val output = LightOutputStream(size + 5)
IntegerBinding.writeCompressed(output, size)
output.write(cluster, 0, size)
val result = output.asArrayByteIterable()
return clusterConverter?.onWrite(result) ?: result
}
val bi: ByteIterable
try {
val file = File.createTempFile("~exodus-vfs-output-cluster", ".tmp")
RandomAccessFile(file, "rw").use { out -> out.write(cluster, 0, size) }
bi = FileByteIterable(file)
file.deleteOnExit()
} catch (e: IOException) {
throw ExodusException.toExodusException(e)
}
return CompoundByteIterable(arrayOf(IntegerBinding.intToCompressedEntry(size), bi))
}
}
}