Abbreviator xref

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    1   /**
    2    * Copyright (c) 2004-2011 QOS.ch
    3    * All rights reserved.
    4    *
    5    * Permission is hereby granted, free  of charge, to any person obtaining
    6    * a  copy  of this  software  and  associated  documentation files  (the
    7    * "Software"), to  deal in  the Software without  restriction, including
    8    * without limitation  the rights to  use, copy, modify,  merge, publish,
    9    * distribute,  sublicense, and/or sell  copies of  the Software,  and to
    10   * permit persons to whom the Software  is furnished to do so, subject to
    11   * the following conditions:
    12   *
    13   * The  above  copyright  notice  and  this permission  notice  shall  be
    14   * included in all copies or substantial portions of the Software.
    15   *
    16   * THE  SOFTWARE IS  PROVIDED  "AS  IS", WITHOUT  WARRANTY  OF ANY  KIND,
    17   * EXPRESS OR  IMPLIED, INCLUDING  BUT NOT LIMITED  TO THE  WARRANTIES OF
    18   * MERCHANTABILITY,    FITNESS    FOR    A   PARTICULAR    PURPOSE    AND
    19   * NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE
    20   * LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION
    21   * OF CONTRACT, TORT OR OTHERWISE,  ARISING FROM, OUT OF OR IN CONNECTION
    22   * WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
    23   *
    24   */
    25  package org.slf4j.migrator.helper;
    26
    27  public class Abbreviator {
    28    static final String FILLER = "...";
    29
    30    final char folderSeparator;
    31    final int invariantPrefixLength;
    32    final int desiredLength;
    33
    34    public Abbreviator(int invariantPrefixLength, int desiredLength,
    35        char folderSeparator) {
    36      this.invariantPrefixLength = invariantPrefixLength;
    37      this.desiredLength = desiredLength;
    38      this.folderSeparator = folderSeparator;
    39    }
    40
    41    public String abbreviate(String filename) {
    42      if (filename.length() <= desiredLength) {
    43        return filename;
    44      } else {
    45
    46        int firstIndex = filename.indexOf(folderSeparator, invariantPrefixLength);
    47        if (firstIndex == -1) {
    48          // we cant't process this string
    49          return filename;
    50        }
    51        StringBuffer buf = new StringBuffer(desiredLength);
    52        buf.append(filename.substring(0, firstIndex + 1));
    53        buf.append(FILLER);
    54        int nextIndex = computeNextIndex(filename, firstIndex);
    55        if (nextIndex != -1) {
    56          buf.append(filename.substring(nextIndex));
    57        } else {
    58          // better long than wrong
    59          return filename;
    60        }
    61
    62        if (buf.length() < filename.length()) {
    63          return buf.toString();
    64        } else {
    65          // we tried our best but we are still could not shorten the input
    66          return filename;
    67        }
    68      }
    69    }
    70
    71    int computeNextIndex(String filename, int firstIndex) {
    72      int nextIndex = firstIndex + 1;
    73      int hitCount = 0;
    74      int minToRemove = filename.length() - desiredLength + FILLER.length();
    75      while (nextIndex < firstIndex + minToRemove) {
    76        int tmpIndex = filename.indexOf(folderSeparator, nextIndex + 1);
    77        if (tmpIndex == -1) {
    78          if (hitCount == 0) {
    79            return -1;
    80          } else {
    81            return nextIndex;
    82          }
    83        } else {
    84          hitCount++;
    85          nextIndex = tmpIndex;
    86        }
    87      }
    88      return nextIndex;
    89    }
    90  }