Paper-based Asynchronous Cache for looking up blocks.

ChunkSnapshotCache.java

public class ChunkSnapshotCache {
    private final LoadingCache<StringChunk, ChunkSnapshot> cache;
    private ChunkSnapshotCache() {
        cache = CacheBuilder.newBuilder()
                .build(new CacheLoader<StringChunk, ChunkSnapshot>() {
                    @Override
                    public ChunkSnapshot load(StringChunk chunk) {
                        return chunk.getChunk().getChunkSnapshot(false, false, false);
                    }
                });
    }

    public StringBlock getCleanBlock(StringBlock liveBlock) {
        World cleanWorld = Bukkit.getWorld(liveBlock.getWorld() + "_clean");
        StringChunk chunk = new StringChunk(cleanWorld, liveBlock.getBlockX() >> 4, liveBlock.getBlockZ() >> 4);
        ChunkSnapshot cleanSnapshot = cache.getUnchecked(chunk);
        int x = liveBlock.getBlockX();
        int y = liveBlock.getBlockY();
        int z = liveBlock.getBlockZ();
        return new StringBlock(cleanWorld, x, y, z,
                cleanSnapshot.getBlockType(x, y, z),
                (byte) cleanSnapshot.getBlockData(x, y, z));
    }
}