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