TransformingResource

All Implemented Interfaces:

org.readium.r2.shared.fetcher.Resource , org.readium.r2.shared.util.SuspendingCloseable
```
public abstract class TransformingResource
extends ProxyResource
                    
```
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.

Nested Class Summary

Nested Classes
Modifier and Type	Class	Description
`public class`	`TransformingResource.Companion`

Field Summary

Fields
Modifier and Type	Field	Description
`private final File`	`file`

Constructor Summary

Constructors
Constructor	Description
`TransformingResource(Resource resource, Boolean cacheBytes)`

Enum Constant Summary

Enum Constants
Enum Constant	Description

Method Summary

Modifier and Type	Method	Description
`abstract Try<ByteArray, Resource.Exception>`	`transform(Try<ByteArray, Resource.Exception> data)`
`Try<ByteArray, Resource.Exception>`	`read(LongRange range)`	Reads the bytes at the given range.
`Try<Long, Resource.Exception>`	`length()`	Returns data length from metadata if available, or calculated from reading the bytes otherwise.

Methods inherited from class org.readium.r2.shared.fetcher.ProxyResource
close, getFile, link, toString
Methods inherited from class org.readium.r2.shared.fetcher.Resource
readAsBitmap, readAsJson, readAsString, readAsXml
Methods inherited from class java.lang.Object
clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

- Constructor Detail
  - TransformingResource
```
TransformingResource(Resource resource, Boolean cacheBytes)
```
- Method Detail
  - transform
```
 abstract Try<ByteArray, Resource.Exception> transform(Try<ByteArray, Resource.Exception> data)
```
  - read
```
 Try<ByteArray, Resource.Exception> read(LongRange range)
```
    Reads the bytes at the given range.
    When range is null, the whole content is returned. Out-of-range indexes are clamped to the available length automatically.
  - length
```
 Try<Long, Resource.Exception> length()
```
    Returns data length from metadata if available, or calculated from reading the bytes otherwise.
    This value must be treated as a hint, as it might not reflect the actual bytes length. To get the real length, you need to read the whole resource.