readium-shared/org.readium.r2.shared.util.resource/TransformingResource

TransformingResource

abstract class TransformingResource(resource: Resource, cacheBytes: Boolean = true) : Resource

Transforms the bytes of resource on-the-fly.

If you set cacheBytes to false, consider providing your own implementation of length to avoid unnecessary transformations.

Warning: The transformation runs on the full content of resource, so it's not appropriate for large resources which can't be held in memory.

Constructors

TransformingResource

constructor(resource: Resource, cacheBytes: Boolean = true)

Types

Companion

object Companion

Properties

sourceUrl

open override val sourceUrl: AbsoluteUrl? = null

URL locating this resource, if any.

Functions

asInputStream

fun Readable.asInputStream(range: LongRange? = null, wrapError: (ReadError) -> IOException = { ReadException(it) }): InputStream

Wraps a Readable into an InputStream.

borrow

fun Readable.borrow(): Readable

Returns a new Readable accessing the same data but not owning them.

fun Resource.borrow(): Resource

Returns a new Resource accessing the same data but not owning them.

buffered

fun Readable.buffered(contentLength: Long? = null, bufferSize: Int = DEFAULT_BUFFER_SIZE): Readable

Wraps this resource into a buffer to improve reading performances.

fun Resource.buffered(resourceLength: Long? = null, bufferSize: Int = DEFAULT_BUFFER_SIZE): BufferingResource

Wraps this resource in a BufferingResource to improve reading performances.

open override fun close()

Closes this object and releases any resources associated with it. If the object is already closed then invoking this method has no effect.

fallback

fun Resource.fallback(fallbackResourceFactory: (ReadError) -> Resource?): Resource

Falls back to alternative resources when the receiver fails.

fun Resource.fallback(fallbackResource: Resource): Resource

Falls back to the given alternative Resource when the receiver fails.

flatMap

fun <R : Resource> Resource.flatMap(transform: suspend (Resource) -> R): LazyResource

length

open suspend override fun length(): Try<Long, ReadError>

Returns data length from metadata if available, or calculated from reading the bytes otherwise.

map

fun Resource.map(transform: suspend (ByteArray) -> Try<ByteArray, ReadError>): Resource

properties

open suspend override fun properties(): Try<Resource.Properties, ReadError>

Properties associated to the resource.

read

open suspend override fun read(range: LongRange?): Try<ByteArray, ReadError>

Reads the bytes at the given range.

readDecodeOrElse

inline suspend fun <R> Readable.readDecodeOrElse(decode: (value: ByteArray) -> Try<R, DecodeError>, recover: (ReadError) -> R): R

inline suspend fun <R> Readable.readDecodeOrElse(decode: (value: ByteArray) -> Try<R, DecodeError>, recoverRead: (ReadError) -> R, recoverDecode: (DecodeError.Decoding) -> R): R

readDecodeOrNull

inline suspend fun <R> Readable.readDecodeOrNull(decode: (value: ByteArray) -> Try<R, DecodeError>): R?

readOrElse

inline suspend fun Readable.readOrElse(recover: (ReadError) -> ByteArray): ByteArray

synchronized

fun Resource.synchronized(): SynchronizedResource

Wraps this resource in a SynchronizedResource to protect the access from multiple threads.

transform

abstract suspend fun transform(data: Try<ByteArray, ReadError>): Try<ByteArray, ReadError>