com.facebook.buck.util.network.AbstractBatchingLogger.java Source code

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Here is the source code for com.facebook.buck.util.network.AbstractBatchingLogger.java

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/*
 * Copyright 2015-present Facebook, Inc.
 *
 * 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.facebook.buck.util.network;

import com.google.common.base.Objects;
import com.google.common.collect.ImmutableCollection;
import com.google.common.collect.ImmutableList;
import com.google.common.util.concurrent.Futures;
import com.google.common.util.concurrent.ListenableFuture;

import java.util.Optional;

/**
 * Common functionality for uploading log entries in batches.
 */
public abstract class AbstractBatchingLogger implements BatchingLogger {

    public static final int DEFAULT_MIN_BATCH_SIZE = 1024 * 128; // This is pretty arbitrary.

    protected static class BatchEntry {
        private final String line;

        public BatchEntry(String line) {
            this.line = line;
        }

        public String getLine() {
            return line;
        }

        @Override
        public boolean equals(Object other) {
            if (!(other instanceof BatchEntry)) {
                return false;
            }

            BatchEntry that = (BatchEntry) other;
            return line.equals(that.line);
        }

        @Override
        public int hashCode() {
            return Objects.hashCode(line);
        }

        @Override
        public String toString() {
            return String.format("BatchEntry(%s)", line);
        }
    }

    private ImmutableList.Builder<BatchEntry> batch;
    private int currentBatchSize;
    private final int minBatchSize;

    public AbstractBatchingLogger(int minBatchSize) {
        this.batch = ImmutableList.builder();
        this.currentBatchSize = 0;
        this.minBatchSize = minBatchSize;
    }

    public AbstractBatchingLogger() {
        this(DEFAULT_MIN_BATCH_SIZE);
    }

    @Override
    public final Optional<ListenableFuture<Void>> log(String logLine) {
        batch.add(new BatchEntry(logLine));
        currentBatchSize += logLine.length();
        if (currentBatchSize >= minBatchSize) {
            return Optional.of(sendBatch());
        }
        return Optional.empty();
    }

    @Override
    public final ListenableFuture<Void> forceFlush() {
        return sendBatch();
    }

    private ListenableFuture<Void> sendBatch() {
        ImmutableList<BatchEntry> toSend = batch.build();
        batch = ImmutableList.builder();
        currentBatchSize = 0;
        if (toSend.isEmpty()) {
            return Futures.immediateFuture(null);
        } else {
            return logMultiple(toSend);
        }
    }

    protected abstract ListenableFuture<Void> logMultiple(ImmutableCollection<BatchEntry> data);
}