Jo Shields a575963da9 Imported Upstream version 3.6.0
Former-commit-id: da6be194a6b1221998fc28233f2503bd61dd9d14
2014-08-13 10:39:27 +01:00

122 lines
3.9 KiB
C#

//
// UserRangePartitioner.cs
//
// Author:
// Jérémie "Garuma" Laval <jeremie.laval@gmail.com>
//
// Copyright (c) 2010 Jérémie "Garuma" Laval
//
// Permission is hereby granted, free of charge, to any person obtaining a copy
// of this software and associated documentation files (the "Software"), to deal
// in the Software without restriction, including without limitation the rights
// to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
// copies of the Software, and to permit persons to whom the Software is
// furnished to do so, subject to the following conditions:
//
// The above copyright notice and this permission notice shall be included in
// all copies or substantial portions of the Software.
//
// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
// IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
// FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
// AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
// LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
// OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
// THE SOFTWARE.
#if NET_4_0
using System;
using System.Threading;
using System.Collections.Generic;
namespace System.Collections.Concurrent.Partitioners
{
internal class UserRangePartitioner : OrderablePartitioner<Tuple<int, int>>
{
readonly int start;
readonly int end;
readonly int rangeSize;
public UserRangePartitioner (int start, int end, int rangeSize) : base (true, true, true)
{
this.start = start;
this.end = end;
this.rangeSize = rangeSize;
}
public override IList<IEnumerator<KeyValuePair<long, Tuple<int, int>>>> GetOrderablePartitions (int partitionCount)
{
if (partitionCount <= 0)
throw new ArgumentOutOfRangeException ("partitionCount");
int currentIndex = 0;
Func<int> getNextIndex = () => Interlocked.Increment (ref currentIndex) - 1;
var enumerators = new IEnumerator<KeyValuePair<long, Tuple<int, int>>>[partitionCount];
for (int i = 0; i < partitionCount; i++)
enumerators[i] = GetEnumerator (getNextIndex);
return enumerators;
}
IEnumerator<KeyValuePair<long, Tuple<int, int>>> GetEnumerator (Func<int> getNextIndex)
{
while (true) {
int index = getNextIndex ();
int sliceStart = index * rangeSize + start;
if (sliceStart >= end)
break;
yield return new KeyValuePair<long, Tuple<int, int>> (index, Tuple.Create (sliceStart, Math.Min (end, sliceStart + rangeSize)));
sliceStart += rangeSize;
}
}
}
internal class UserLongRangePartitioner : OrderablePartitioner<Tuple<long, long>>
{
readonly long start;
readonly long end;
readonly long rangeSize;
public UserLongRangePartitioner (long start, long end, long rangeSize) : base (true, true, true)
{
this.start = start;
this.end = end;
this.rangeSize = rangeSize;
}
public override IList<IEnumerator<KeyValuePair<long, Tuple<long, long>>>> GetOrderablePartitions (int partitionCount)
{
if (partitionCount <= 0)
throw new ArgumentOutOfRangeException ("partitionCount");
long currentIndex = 0;
Func<long> getNextIndex = () => Interlocked.Increment (ref currentIndex) - 1;
var enumerators = new IEnumerator<KeyValuePair<long, Tuple<long, long>>>[partitionCount];
for (int i = 0; i < partitionCount; i++)
enumerators[i] = GetEnumerator (getNextIndex);
return enumerators;
}
IEnumerator<KeyValuePair<long, Tuple<long, long>>> GetEnumerator (Func<long> getNextIndex)
{
while (true) {
long index = getNextIndex ();
long sliceStart = index * rangeSize + start;
if (sliceStart >= end)
break;
yield return new KeyValuePair<long, Tuple<long, long>> (index, Tuple.Create (sliceStart, Math.Min (end, sliceStart + rangeSize)));
sliceStart += rangeSize;
}
}
}
}
#endif