com.intel.cosbench.driver.iterator.RangeIterator.java Source code

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Here is the source code for com.intel.cosbench.driver.iterator.RangeIterator.java

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/** 
     
Copyright 2013 Intel Corporation, All Rights Reserved.
    
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.intel.cosbench.driver.iterator;

import org.apache.commons.lang.StringUtils;

import com.intel.cosbench.config.ConfigException;

class RangeIterator implements IntIterator {

    private int lower;
    private int upper;

    public RangeIterator(int lower, int upper) {
        if (lower <= 0 || upper <= 0 || lower > upper)
            throw new IllegalArgumentException();
        this.lower = lower;
        this.upper = upper;
    }

    @Override
    public int next(int cursor) {
        return next(cursor, 1, 1);
    }

    @Override
    public int next(int cursor, int idx, int all) {
        int range = upper - lower + 1;
        int base = range / all;
        int extra = range % all;
        int offset = base * (idx - 1) + (extra >= idx - 1 ? idx - 1 : extra);
        int segment = base + (extra >= idx ? 1 : 0);
        int limit = segment + offset + lower;
        cursor = cursor <= 0 ? limit - segment : cursor + 1;
        return cursor < limit ? cursor : -1;
    }

    public static RangeIterator parse(String pattern) {
        try {
            return tryParseOld(pattern);
        } catch (Exception e1) {
            if (!StringUtils.startsWith(pattern, "r("))
                return null;
            try {
                return tryParse(pattern);
            } catch (Exception e2) {
            }
        }
        String msg = "illegal iteration pattern: " + pattern;
        throw new ConfigException(msg);
    }

    private static RangeIterator tryParse(String pattern) {
        pattern = StringUtils.substringBetween(pattern, "(", ")");
        String[] args = StringUtils.split(pattern, ",");
        int lower = Integer.parseInt(args[0]);
        int upper = Integer.parseInt(args[1]);
        return new RangeIterator(lower, upper);
    }

    private static RangeIterator tryParseOld(String pattern) {
        String[] args = StringUtils.split(pattern, '-');
        int lower = Integer.parseInt(args[0]);
        int upper = Integer.parseInt(args[1]);
        return new RangeIterator(lower, upper);
    }

}