smengcl commented on code in PR #4315:
URL: https://github.com/apache/ozone/pull/4315#discussion_r1129957455


##########
hadoop-hdds/rocks-native/src/main/java/org/apache/hadoop/hdds/utils/db/managed/PipeInputStream.java:
##########
@@ -0,0 +1,81 @@
+package org.apache.hadoop.hdds.utils.db.managed;
+
+import org.apache.hadoop.hdds.utils.NativeLibraryLoader;
+import org.apache.hadoop.hdds.utils.NativeLibraryNotLoadedException;
+import java.io.InputStream;
+import java.util.concurrent.atomic.AtomicBoolean;
+
+import static 
org.apache.hadoop.hdds.utils.NativeConstants.ROCKS_TOOLS_NATIVE_LIBRARY_NAME;
+
+/**
+ * JNI for reading data from pipe.
+ */
+public class PipeInputStream extends InputStream {
+
+  static {
+    NativeLibraryLoader.getInstance()
+            .loadLibrary(ROCKS_TOOLS_NATIVE_LIBRARY_NAME);
+  }
+  private byte[] byteBuffer;
+  private long nativeHandle;
+  private int numberOfBytesLeftToRead;
+  private int index = 0;
+  private int capacity;
+
+  private AtomicBoolean cleanup;
+
+  PipeInputStream(int capacity) throws NativeLibraryNotLoadedException {
+    if (!NativeLibraryLoader.getInstance()
+            .isLibraryLoaded(ROCKS_TOOLS_NATIVE_LIBRARY_NAME)) {
+      throw new NativeLibraryNotLoadedException(
+              ROCKS_TOOLS_NATIVE_LIBRARY_NAME);
+    }
+
+    this.byteBuffer = new byte[capacity];
+    this.numberOfBytesLeftToRead = 0;
+    this.capacity = capacity;
+    this.nativeHandle = newPipe();
+    this.cleanup = new AtomicBoolean(false);
+  }
+
+  long getNativeHandle() {
+    return nativeHandle;
+  }
+
+  @Override
+  public int read() {
+    if (numberOfBytesLeftToRead < 0) {
+      this.close();
+      return -1;
+    }
+    if (numberOfBytesLeftToRead == 0) {
+      numberOfBytesLeftToRead = readInternal(byteBuffer, capacity,
+              nativeHandle);
+      index = 0;
+      return read();
+    }
+    numberOfBytesLeftToRead--;
+    int ret = byteBuffer[index] & 0xFF;
+    index += 1;
+    return ret;
+  }
+
+  private native long newPipe();
+
+  private native int readInternal(byte[] buff, int numberOfBytes,
+                                  long pipeHandle);
+  private native void closeInternal(long pipeHandle);
+
+  @Override
+  public void close() {
+    if (this.cleanup.compareAndSet(false, true)) {
+      closeInternal(this.nativeHandle);
+    }
+  }
+
+  @Override
+  protected void finalize() throws Throwable {
+    close();
+    super.finalize();
+  }
+}

Review Comment:
   See HDDS-8077



-- 
This is an automated message from the Apache Git Service.
To respond to the message, please log on to GitHub and use the
URL above to go to the specific comment.

To unsubscribe, e-mail: [email protected]

For queries about this service, please contact Infrastructure at:
[email protected]


---------------------------------------------------------------------
To unsubscribe, e-mail: [email protected]
For additional commands, e-mail: [email protected]

Reply via email to