Import code from internal repository to git

java/com/google/domain/registry/util/ImprovedOutputStream.java

@@ -0,0 +1,130 @@
+// Copyright 2016 Google Inc. All Rights Reserved.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package com.google.domain.registry.util;
+
+import static com.google.common.base.Preconditions.checkArgument;
+import static com.google.common.base.Preconditions.checkNotNull;
+
+import java.io.FilterOutputStream;
+import java.io.IOException;
+import java.io.OutputStream;
+
+import javax.annotation.OverridingMethodsMustInvokeSuper;
+import javax.annotation.WillCloseWhenClosed;
+import javax.annotation.concurrent.NotThreadSafe;
+
+/**
+ * {@link OutputStream} wrapper that offers some additional magic.
+ *
+ * <ul>
+ * <li>Byte counting
+ * <li>Always {@link #flush()} on {@link #close()}
+ * <li>Check expected byte count when closed (Optional)
+ * <li>Close original {@link OutputStream} when closed (Optional)
+ * <li>Overridable {@link #onClose()} method
+ * <li>Throws {@link NullPointerException} if written after {@link #close()}
+ * </ul>
+ *
+ * @see ImprovedInputStream
+ * @see com.google.common.io.CountingOutputStream
+ */
+@NotThreadSafe
+public class ImprovedOutputStream extends FilterOutputStream {
+
+  private static final FormattingLogger logger = FormattingLogger.getLoggerForCallerClass();
+
+  private long count;
+  private final long expected;
+  private final boolean shouldClose;
+
+  public ImprovedOutputStream(@WillCloseWhenClosed OutputStream out) {
+    this(out, true, -1);
+  }
+
+  public ImprovedOutputStream(OutputStream out, boolean shouldClose, long expected) {
+    super(checkNotNull(out, "out"));
+    checkArgument(expected >= -1, "expected >= 0 or -1");
+    this.shouldClose = shouldClose;
+    this.expected = expected;
+  }
+
+  /** Returns the number of bytes that have been written to this stream thus far. */
+  public long getBytesWritten() {
+    return count;
+  }
+
+  /** @see java.io.FilterOutputStream#write(int) */
+  @Override
+  @OverridingMethodsMustInvokeSuper
+  public void write(int b) throws IOException {
+    out.write(b);
+    ++count;
+  }
+
+  /** @see #write(byte[], int, int) */
+  @Override
+  public final void write(byte[] b) throws IOException {
+    this.write(b, 0, b.length);
+  }
+
+  /** @see java.io.FilterOutputStream#write(byte[], int, int) */
+  @Override
+  @OverridingMethodsMustInvokeSuper
+  public void write(byte[] b, int off, int len) throws IOException {
+    out.write(b, off, len);
+    count += len;
+  }
+
+  /**
+   * Flushes, logs byte count, checks byte count (optional), closes (optional), and self-sabotages.
+   *
+   * <p>This method may not be overridden, use {@link #onClose()} instead.
+   *
+   * @see java.io.OutputStream#close()
+   */
+  @Override
+  @NonFinalForTesting
+  public void close() throws IOException {
+    if (out == null) {
+      return;
+    }
+    try {
+      flush();
+    } catch (IOException e) {
+      logger.warningfmt(e, "%s.flush() failed", getClass().getSimpleName());
+    }
+    logger.infofmt("%s closed with %,d bytes written", getClass().getSimpleName(), count);
+    if (expected != -1 && count != expected) {
+      throw new IOException(String.format(
+          "%s expected %,d bytes but got %,d bytes", getClass().getSimpleName(), expected, count));
+    }
+    onClose();
+    if (shouldClose) {
+      out.close();
+    }
+    out = null;
+  }
+
+  /**
+   * Overridable method that's called by {@link #close()}.
+   *
+   * <p>This method does nothing by default.
+   *
+   * @throws IOException
+   */
+  protected void onClose() throws IOException {
+    // Does nothing by default.
+  }
+}