less requests to store on read

Author: brokkoli71

src/main/java/dev/zarr/zarrjava/core/Array.java

@@ -16,6 +16,9 @@
 import java.nio.file.Path;
 import java.nio.file.Paths;
 import java.util.Arrays;
+import java.util.List;
+import java.util.Set;
+import java.util.stream.Collectors;
 import java.util.stream.Stream;
 
 public abstract class Array extends AbstractNode {
@@ -289,6 +292,8 @@ public ucar.ma2.Array read(final long[] offset, final int[] shape, final boolean
         if (parallel) {
             chunkStream = chunkStream.parallel();
         }
+        final Set<List<String>> existingKeys = storeHandle.list().map(Arrays::asList).collect(Collectors.toSet());
+
         chunkStream.forEach(
                 chunkCoords -> {
                     try {
@@ -306,9 +311,8 @@ public ucar.ma2.Array read(final long[] offset, final int[] shape, final boolean
 
                         final String[] chunkKeys = metadata.chunkKeyEncoding().encodeChunkKey(chunkCoords);
                         final StoreHandle chunkHandle = storeHandle.resolve(chunkKeys);
-                        if (!chunkHandle.exists()) {
+                        if (existingKeys.stream().noneMatch(Arrays.asList(chunkKeys)::equals))
                             return;
-                        }
                         if (codecPipeline.supportsPartialDecode()) {
                             final ucar.ma2.Array chunkArray = codecPipeline.decodePartial(chunkHandle,
                                     Utils.toLongArray(chunkProjection.chunkOffset), chunkProjection.shape);