/*
    * Copyright (C) 2022, Tencent.
    *
    * This program and the accompanying materials are made available under the
    * terms of the Eclipse Distribution License v. 1.0 which is available at
    * https://www.eclipse.org/org/documents/edl-v10.php.
    *
    * SPDX-License-Identifier: BSD-3-Clause
    */
  
  package org.eclipse.jgit.internal.storage.io;
  
  import static org.eclipse.jgit.internal.storage.io.CancellableDigestOutputStream.BYTES_TO_WRITE_BEFORE_CANCEL_CHECK;
  import static org.junit.Assert.assertEquals;
  import static org.junit.Assert.assertThrows;
  import static org.junit.Assert.assertTrue;
  
  import java.io.InterruptedIOException;
  
  import org.eclipse.jgit.lib.ProgressMonitor;
  import org.eclipse.jgit.util.io.NullOutputStream;
  import org.junit.Test;
  
  public class CancellableDigestOutputStreamTest {
  	private static class CancelledTestMonitor implements ProgressMonitor {
  
  		private boolean cancelled = false;
  
  		public void setCancelled(boolean cancelled) {
  			this.cancelled = cancelled;
  		}
  
  		@Override
  		public void start(int totalTasks) {
  			// not implemented
  		}
  
  		@Override
  		public void beginTask(String title, int totalWork) {
  			// not implemented
  		}
  
  		@Override
  		public void update(int completed) {
  			// not implemented
  		}
  
  		@Override
  		public void endTask() {
  			// not implemented
  		}
  
  		@Override
  		public boolean isCancelled() {
  			return cancelled;
  		}
  	}
  
  	@Test
  	public void testCancelInProcess() throws Exception {
  		CancelledTestMonitor m = new CancelledTestMonitor();
  		try (CancellableDigestOutputStream out = new CancellableDigestOutputStream(
  				m, NullOutputStream.INSTANCE)) {
  			byte[] KB = new byte[1024];
  			int triggerCancelWriteCnt = BYTES_TO_WRITE_BEFORE_CANCEL_CHECK
  					/ KB.length;
  			for (int i = 0; i < triggerCancelWriteCnt + 1; i++) {
  				out.write(KB);
  			}
  			assertTrue(out.length() > BYTES_TO_WRITE_BEFORE_CANCEL_CHECK);
  			m.setCancelled(true);
  
  			for (int i = 0; i < triggerCancelWriteCnt - 1; i++) {
  				out.write(KB);
  			}
  
  			long lastLength = out.length();
  			assertThrows(InterruptedIOException.class, () -> {
  				out.write(1);
  			});
  			assertEquals(lastLength, out.length());
  
  			assertThrows(InterruptedIOException.class, () -> {
  				out.write(new byte[1]);
  			});
  			assertEquals(lastLength, out.length());
  		}
  	}
  
  	@Test
  	public void testTriggerCheckAfterSingleBytes() throws Exception {
  		CancelledTestMonitor m = new CancelledTestMonitor();
  		try (CancellableDigestOutputStream out = new CancellableDigestOutputStream(
  				m, NullOutputStream.INSTANCE)) {
  
  			byte[] bytes = new byte[BYTES_TO_WRITE_BEFORE_CANCEL_CHECK + 1];
  			m.setCancelled(true);
  
  			assertThrows(InterruptedIOException.class, () -> {
 				out.write(bytes);
 			});
 			assertEquals(BYTES_TO_WRITE_BEFORE_CANCEL_CHECK, out.length());
 		}
 	}
 }