accumulo-dev mailing list archives

Site index · List index
Message view « Date » · « Thread »
Top « Date » · « Thread »
From ShawnWalker <...@git.apache.org>
Subject [GitHub] accumulo pull request: ACCUMULO-4187: Added rate limiting for majo...
Date Wed, 13 Apr 2016 16:27:54 GMT
Github user ShawnWalker commented on a diff in the pull request:

    https://github.com/apache/accumulo/pull/90#discussion_r59579822
  
    --- Diff: core/src/main/java/org/apache/accumulo/core/file/streams/PositionedOutputs.java
---
    @@ -0,0 +1,55 @@
    +/*
    + * Licensed to the Apache Software Foundation (ASF) under one or more
    + * contributor license agreements.  See the NOTICE file distributed with
    + * this work for additional information regarding copyright ownership.
    + * The ASF licenses this file to You 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 org.apache.accumulo.core.file.streams;
    +
    +import java.io.FilterOutputStream;
    +import java.io.IOException;
    +import java.io.OutputStream;
    +import org.apache.hadoop.fs.FSDataOutputStream;
    +
    +public class PositionedOutputs {
    +  public static PositionedOutputStream wrap(final OutputStream fout) {
    +    if (fout instanceof FSDataOutputStream) {
    +      return new PositionedOutputStream(fout) {
    +        @Override
    +        public long position() throws IOException {
    +          return ((FSDataOutputStream) fout).getPos();
    +        }
    +      };
    +    } else if (fout instanceof PositionedOutput) {
    +      return new PositionedOutputStream(fout) {
    +        @Override
    +        public long position() throws IOException {
    +          return ((PositionedOutput) fout).position();
    +        }
    +      };
    +    } else {
    +      return new PositionedOutputStream(fout) {
    +        @Override
    +        public long position() throws IOException {
    +          throw new UnsupportedOperationException("Underlying stream does not support
position()");
    +        }
    +      };
    +    }
    +  }
    +
    +  public static abstract class PositionedOutputStream extends FilterOutputStream implements
PositionedOutput {
    --- End diff --
    
    What I really want to say is "This method returns an `OutputStream` which implements `PositionedOutput`"
 But there's not really a way to say that in Java.
    
    I'm probably just being too clever with `PositionedOutput` anyways.  The underlying issue
is that `BCFile.Writer` needs an `OutputStream` implementing `DataOutput` with some facsimile
of the `getPos()` method from `FSDataOutputStream`.  `RateLimitedOutputStream` doesn't want
to care about or interfere with either of these.  But there doesn't seem to be any way to
separate concerns cleanly.  `getPos()` doesn't have an interface (like `Seekable`), and `java.io.DataOutputStream`
(and so `FSDataOutputStream`) isn't implemented in a way which readily supports subclassing/inheritance.


---
If your project is set up for it, you can reply to this email and have your
reply appear on GitHub as well. If your project does not have this feature
enabled and wishes so, or if the feature is enabled but not working, please
contact infrastructure at infrastructure@apache.org or file a JIRA ticket
with INFRA.
---

Mime
View raw message