Mailing-List: contact issues-help@nifi.apache.org; run by ezmlm
Precedence: bulk
Reply-To: dev@nifi.apache.org
From: markap14 <git@git.apache.org>
To: issues@nifi.apache.org
Reply-To: issues@nifi.apache.org
References: <git-pr-1493-nifi@git.apache.org>
In-Reply-To: <git-pr-1493-nifi@git.apache.org>
Subject: [GitHub] nifi pull request #1493: NIFI-3356: Initial implementation of writeahead pro...
Content-Type: text/plain
Message-Id: <20170214174948.B1990DFCA3@git1-us-west.apache.org>
Date: Tue, 14 Feb 2017 17:49:48 +0000 (UTC)
archived-at: Tue, 14 Feb 2017 17:49:50 -0000

Github user markap14 commented on a diff in the pull request:

    https://github.com/apache/nifi/pull/1493#discussion_r101097703
  
    --- Diff: nifi-nar-bundles/nifi-framework-bundle/nifi-framework/nifi-framework-core/src/main/java/org/apache/nifi/controller/repository/claim/ContentClaimWriteCache.java ---
    @@ -0,0 +1,168 @@
    +/*
    + * 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.nifi.controller.repository.claim;
    +
    +import java.io.BufferedOutputStream;
    +import java.io.IOException;
    +import java.io.OutputStream;
    +import java.util.HashMap;
    +import java.util.LinkedList;
    +import java.util.Map;
    +import java.util.Queue;
    +
    +import org.apache.nifi.controller.repository.ContentRepository;
    +import org.apache.nifi.stream.io.ByteCountingOutputStream;
    +
    +public class ContentClaimWriteCache {
    +    private final ContentRepository contentRepo;
    +    private final Map<ResourceClaim, ByteCountingOutputStream> streamMap = new HashMap<>();
    +    private final Queue<ContentClaim> queue = new LinkedList<>();
    +    private final int bufferSize;
    +
    +    public ContentClaimWriteCache(final ContentRepository contentRepo) {
    +        this(contentRepo, 8192);
    +    }
    +
    +    public ContentClaimWriteCache(final ContentRepository contentRepo, final int bufferSize) {
    +        this.contentRepo = contentRepo;
    +        this.bufferSize = bufferSize;
    +    }
    +
    +    public void reset() throws IOException {
    +        try {
    +            forEachStream(OutputStream::close);
    +        } finally {
    +            streamMap.clear();
    +            queue.clear();
    +        }
    +    }
    +
    +    public ContentClaim getContentClaim() throws IOException {
    +        final ContentClaim contentClaim = queue.poll();
    +        if (contentClaim != null) {
    +            contentRepo.incrementClaimaintCount(contentClaim);
    +            return contentClaim;
    +        }
    +
    +        final ContentClaim claim = contentRepo.create(false);
    +        registerStream(claim);
    +        return claim;
    +    }
    +
    +    private ByteCountingOutputStream registerStream(final ContentClaim contentClaim) throws IOException {
    +        final OutputStream out = contentRepo.write(contentClaim);
    +        final OutputStream buffered = new BufferedOutputStream(out, bufferSize);
    +        final ByteCountingOutputStream bcos = new ByteCountingOutputStream(buffered);
    +        streamMap.put(contentClaim.getResourceClaim(), bcos);
    +        return bcos;
    +    }
    +
    +    public OutputStream write(final ContentClaim claim) throws IOException {
    --- End diff --
    
    I called it write() to mimic the naming using in ContentRepository, as this made the transition of StandardProcessSession a little easier to comprehend. At least that was my intention :)


---
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.
---