65 lines
2.2 KiB
Kotlin
65 lines
2.2 KiB
Kotlin
package sushi.hardcore.droidfs.file_viewers
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import android.net.Uri
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import com.google.android.exoplayer2.C
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import com.google.android.exoplayer2.upstream.DataSource
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import com.google.android.exoplayer2.upstream.DataSpec
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import com.google.android.exoplayer2.upstream.TransferListener
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import sushi.hardcore.droidfs.Constants
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import sushi.hardcore.droidfs.filesystems.EncryptedVolume
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import kotlin.math.min
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class EncryptedVolumeDataSource(private val encryptedVolume: EncryptedVolume, private val filePath: String): DataSource {
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private var fileHandle = -1L
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private var fileOffset: Long = 0
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private var bytesRemaining: Long = -1
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override fun open(dataSpec: DataSpec): Long {
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fileHandle = encryptedVolume.openFile(filePath)
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fileOffset = dataSpec.position
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val fileSize = encryptedVolume.getAttr(filePath)!!.size
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bytesRemaining = if (dataSpec.length == C.LENGTH_UNSET.toLong()) {
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fileSize - fileOffset
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} else {
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min(fileSize, dataSpec.length)
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}
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return bytesRemaining
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}
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override fun getUri(): Uri {
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return Constants.FAKE_URI
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}
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override fun close() {
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encryptedVolume.closeFile(fileHandle)
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}
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override fun addTransferListener(transferListener: TransferListener) {
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//too lazy to implement this
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}
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override fun read(buffer: ByteArray, offset: Int, readLength: Int): Int {
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val originalOffset = fileOffset
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while (fileOffset < originalOffset+readLength && encryptedVolume.read(
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fileHandle,
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fileOffset,
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buffer,
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offset+(fileOffset-originalOffset),
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(originalOffset+readLength)-fileOffset
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).also { fileOffset += it } > 0
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) {}
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val totalRead = fileOffset-originalOffset
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bytesRemaining -= totalRead
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return if (totalRead == 0L) {
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C.RESULT_END_OF_INPUT
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} else {
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totalRead.toInt()
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}
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}
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class Factory(private val encryptedVolume: EncryptedVolume, private val filePath: String): DataSource.Factory {
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override fun createDataSource(): DataSource {
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return EncryptedVolumeDataSource(encryptedVolume, filePath)
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}
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}
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} |