io.engineblock.activityapi.cyclelog.buffers.results_rle.CycleResultsRLEBufferReadable Maven / Gradle / Ivy
Show all versions of eb-api Show documentation
/*
*
* Copyright 2016 jshook
* 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 io.engineblock.activityapi.cyclelog.buffers.results_rle;
import io.engineblock.activityapi.cyclelog.buffers.CycleResultSegmentsReadable;
import io.engineblock.activityapi.cyclelog.buffers.results.CycleResultsSegment;
import io.engineblock.activityapi.cyclelog.buffers.results.ResultReadable;
import java.nio.ByteBuffer;
import java.util.Iterator;
import java.util.function.Predicate;
/**
* Implements a cycle result segment in a run-length encoded buffer
* that contains the cycle interval and the result in long, long, byte format,
* where the last value (the second long value) is *not* included in the
* cycle inteval. (closed-open interval)
* This is not a threadsafe iterator. It references buffer data
* that is presumed to be access by only one reader for the sake of efficiency.
*/
public class CycleResultsRLEBufferReadable implements CycleResultSegmentsReadable {
public final static int BYTES = Long.BYTES + Long.BYTES + Byte.BYTES;
private final ByteBuffer buf;
// private long count = Long.MIN_VALUE;
// private long min = Long.MAX_VALUE;
public CycleResultsRLEBufferReadable(ByteBuffer buf) {
this.buf = buf;
}
public CycleResultsRLEBufferReadable(int readSizeInSpans, ByteBuffer src) {
readSizeInSpans = readSizeInSpans * BYTES;
int bufsize = Math.min(readSizeInSpans, src.remaining());
byte[] bbuf = new byte[bufsize];
src.get(bbuf);
this.buf = ByteBuffer.wrap(bbuf);
}
public Iterator iterator(Predicate filter) {
return new ResultSpanIterator(buf,filter);
}
// public long getMin() {
// if (min==Long.MAX_VALUE) {
// long min=Long.MAX_VALUE;
// Optional minSeg = StreamSupport.stream(spliterator(), false).min(CycleResultsSegment::compareTo);
// min=minSeg.map(CycleResultsSegment::getMinCycle).orElse(Long.MAX_VALUE);
// }
// return min;
// }
//
// public long getCount() {
// if (count<=0) {
// LongAccumulator acc = new LongAccumulator((l1,l2)->l1+l2,0);
// iterator().forEachRemaining(crs -> acc.accumulate(crs.getCount()));
// count = acc.get();
// }
// return count;
// }
//
@Override
public Iterator iterator() {
return new ResultSpanIterator(buf,null);
}
private class ResultSpanIterator implements Iterator {
private final ByteBuffer iterbuf;
private Predicate filter;
private CycleResultsSegment next;
public ResultSpanIterator(ByteBuffer buf, Predicate filter) {
this.iterbuf = buf;
this.filter = filter;
}
@Override
public boolean hasNext() {
while (next==null && iterbuf.remaining()>0) {
CycleSpanResults csr = read(iterbuf);
if (filter==null || filter.test(csr)) {
next = csr;
}
}
return next!=null;
}
@Override
public CycleResultsSegment next() {
if (next==null) {
hasNext();
if (next==null) {
throw new RuntimeException("Possible call to next() without calling hasNext(). There was no remaining unfiltered data.");
}
}
CycleResultsSegment wasNext = this.next;
next=null;
return wasNext;
}
private CycleSpanResults read(ByteBuffer iterbuf) {
long min = iterbuf.getLong();
long nextMin = iterbuf.getLong();
int result = iterbuf.get();
return new CycleSpanResults(min, nextMin, result);
}
public String toString() {
return "ResultSpanIterator (" + iterbuf.toString() + ")";
}
}
}