src/main/kotlin/net/pterodactylus/sone/core/DefaultImageLoader.kt

   1 package net.pterodactylus.sone.core
   2
   3 import com.google.common.cache.CacheBuilder
   4 import freenet.keys.FreenetURI
   5 import java.io.ByteArrayInputStream
   6 import javax.imageio.ImageIO
   7 import javax.inject.Inject
   8
   9 /**
  10  * [ImageLoader] implementation that uses a simple Guava [com.google.common.cache.Cache].
  11  */
  12 class DefaultImageLoader @Inject constructor(private val freenetInterface: FreenetInterface) : ImageLoader {
  13
  14         private val imageCache = CacheBuilder.newBuilder().build<String, LoadedImage>()
  15         private val callback = object : FreenetInterface.BackgroundFetchCallback {
  16                 override fun loaded(uri: FreenetURI, mimeType: String, data: ByteArray) {
  17                         if (!mimeType.startsWith("image/")) {
  18                                 return
  19                         }
  20                         val image = ByteArrayInputStream(data).use {
  21                                 ImageIO.read(it)
  22                         }
  23                         val loadedImage = LoadedImage(uri.toString(), mimeType, image.width, image.height)
  24                         imageCache.get(uri.toString()) { loadedImage }
  25                 }
  26
  27                 override fun failed(uri: FreenetURI) {
  28                 }
  29         }
  30
  31         override fun toLoadedImage(link: String): LoadedImage? {
  32                 imageCache.getIfPresent(link)?.run {
  33                         return this
  34                 }
  35                 freenetInterface.startFetch(FreenetURI(link), callback)
  36                 return null
  37         }
  38
  39 }