prevent OOM when decoding large region

CHANGELOG.md

@@ -4,6 +4,10 @@ All notable changes to this project will be documented in this file.
 
 ## <a id="unreleased"></a>[Unreleased]
 
+### Fixed
+
+- crash when decoding large region
+
 ## <a id="v1.10.7"></a>[v1.10.7] - 2024-03-12
 
 ### Added

android/app/src/main/kotlin/deckers/thibault/aves/channel/calls/fetchers/RegionFetcher.kt

@@ -12,7 +12,9 @@ import com.bumptech.glide.load.engine.DiskCacheStrategy
 import com.bumptech.glide.request.RequestOptions
 import deckers.thibault.aves.decoder.MultiPageImage
 import deckers.thibault.aves.utils.BitmapRegionDecoderCompat
+import deckers.thibault.aves.utils.BitmapUtils.ARGB_8888_BYTE_SIZE
 import deckers.thibault.aves.utils.BitmapUtils.getBytes
+import deckers.thibault.aves.utils.MemoryUtils
 import deckers.thibault.aves.utils.MimeTypes
 import deckers.thibault.aves.utils.StorageUtils
 import io.flutter.plugin.common.MethodChannel
@@ -73,7 +75,7 @@ class RegionFetcher internal constructor(
                     BitmapRegionDecoderCompat.newInstance(input)
                 }
                 if (newDecoder == null) {
-                    result.error("getRegion-read-null", "failed to open file for mimeType=$mimeType uri=$uri regionRect=$regionRect", null)
+                    result.error("fetch-read-null", "failed to open file for mimeType=$mimeType uri=$uri regionRect=$regionRect", null)
                     return
                 }
                 currentDecoderRef = LastDecoderRef(uri, newDecoder)
@@ -96,14 +98,22 @@ class RegionFetcher internal constructor(
                 regionRect
             }
 
+            // use `Long` as rect size could be unexpectedly large and go beyond `Int` max
+            val targetBitmapSizeBytes: Long = ARGB_8888_BYTE_SIZE.toLong() * effectiveRect.width() * effectiveRect.height() / sampleSize
+            if (!MemoryUtils.canAllocate(targetBitmapSizeBytes)) {
+                // decoding a region that large would yield an OOM when creating the bitmap
+                result.error("fetch-large-region", "Region too large for uri=$uri regionRect=$regionRect", null)
+                return
+            }
+
             val bitmap = decoder.decodeRegion(effectiveRect, options)
             if (bitmap != null) {
                 result.success(bitmap.getBytes(MimeTypes.canHaveAlpha(mimeType), recycle = true))
             } else {
-                result.error("getRegion-null", "failed to decode region for uri=$uri regionRect=$regionRect", null)
+                result.error("fetch-null", "failed to decode region for uri=$uri regionRect=$regionRect", null)
             }
         } catch (e: Exception) {
-            result.error("getRegion-read-exception", "failed to initialize region decoder for uri=$uri regionRect=$regionRect", e.message)
+            result.error("fetch-read-exception", "failed to initialize region decoder for uri=$uri regionRect=$regionRect", e.message)
         }
     }
 

android/app/src/main/kotlin/deckers/thibault/aves/channel/calls/fetchers/SvgRegionFetcher.kt

@@ -11,6 +11,7 @@ import com.caverock.androidsvg.RenderOptions
 import com.caverock.androidsvg.SVG
 import com.caverock.androidsvg.SVGParseException
 import deckers.thibault.aves.metadata.SvgHelper.normalizeSize
+import deckers.thibault.aves.utils.BitmapUtils.ARGB_8888_BYTE_SIZE
 import deckers.thibault.aves.utils.BitmapUtils.getBytes
 import deckers.thibault.aves.utils.MemoryUtils
 import deckers.thibault.aves.utils.StorageUtils
@@ -116,8 +117,4 @@ class SvgRegionFetcher internal constructor(
         val uri: Uri,
         val svg: SVG,
     )
-
-    companion object {
-        const val ARGB_8888_BYTE_SIZE = 4
-    }
 }

android/app/src/main/kotlin/deckers/thibault/aves/utils/BitmapUtils.kt

@@ -20,6 +20,8 @@ object BitmapUtils {
     private val freeBaos = ArrayList<ByteArrayOutputStream>()
     private val mutex = Mutex()
 
+    const val ARGB_8888_BYTE_SIZE = 4
+
     suspend fun Bitmap.getBytes(canHaveAlpha: Boolean = false, quality: Int = 100, recycle: Boolean): ByteArray? {
         val stream: ByteArrayOutputStream
         mutex.withLock {