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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, char folderSeparator) {
    35          this.invariantPrefixLength = invariantPrefixLength;
    36          this.desiredLength = desiredLength;
    37          this.folderSeparator = folderSeparator;
    38      }
    39
    40      public String abbreviate(String filename) {
    41          if (filename.length() <= desiredLength) {
    42              return filename;
    43          } else {
    44
    45              int firstIndex = filename.indexOf(folderSeparator, invariantPrefixLength);
    46              if (firstIndex == -1) {
    47                  // we cant't process this string
    48                  return filename;
    49              }
    50              StringBuilder buf = new StringBuilder(desiredLength);
    51              buf.append(filename, 0, firstIndex + 1);
    52              buf.append(FILLER);
    53              int nextIndex = computeNextIndex(filename, firstIndex);
    54              if (nextIndex != -1) {
    55                  buf.append(filename.substring(nextIndex));
    56              } else {
    57                  // better long than wrong
    58                  return filename;
    59              }
    60
    61              if (buf.length() < filename.length()) {
    62                  return buf.toString();
    63              } else {
    64                  // we tried our best but we are still could not shorten the input
    65                  return filename;
    66              }
    67          }
    68      }
    69
    70      int computeNextIndex(String filename, int firstIndex) {
    71          int nextIndex = firstIndex + 1;
    72          int hitCount = 0;
    73          int minToRemove = filename.length() - desiredLength + FILLER.length();
    74          while (nextIndex < firstIndex + minToRemove) {
    75              int tmpIndex = filename.indexOf(folderSeparator, nextIndex + 1);
    76              if (tmpIndex == -1) {
    77                  if (hitCount == 0) {
    78                      return -1;
    79                  } else {
    80                      return nextIndex;
    81                  }
    82              } else {
    83                  hitCount++;
    84                  nextIndex = tmpIndex;
    85              }
    86          }
    87          return nextIndex;
    88      }
    89  }