Don't close input stream in readCacheFileImpl.

readCacheFileImpl would close the input stream, which caused the next read from that same stream to fail.

Generally we shouldn't close stream which we didn't create.

src/main/java/azgracompress/cache/QuantizationCacheManager.java

@@ -349,17 +349,32 @@ public class QuantizationCacheManager {
      * @return Cache file or null, if exception occurs.
      */
     private static ICacheFile readCacheFileImpl(final InputStream inputStream) {
-        try (final DataInputStream dis = new DataInputStream(inputStream)) {
+        final DataInputStream dis;
+        if (inputStream instanceof DataInputStream) {
+            dis = (DataInputStream) inputStream;
+        } else {
+            dis = new DataInputStream(inputStream);
+        }
+
         final CacheFileHeader header = new CacheFileHeader();
+        try {
             header.readFromStream(dis);
+        } catch (final IOException e) {
+            System.err.println("Failed to read CacheFileHeader from input stream");
+            e.printStackTrace();
+            return null;
+        }
 
         final ICacheFile cacheFile = getCacheFile(header.getQuantizationType());
         assert (cacheFile != null);
+        try {
             cacheFile.readFromStream(dis, header);
-            return cacheFile;
         } catch (final IOException e) {
+            System.err.println("Failed to read cache file from input stream.");
+            e.printStackTrace();
             return null;
         }
+        return cacheFile;
     }
 
     /**