org.spearce.jgit/src/org/spearce/jgit/revwalk/FIFORevQueue.java

   1 /*
   2  * Copyright (C) 2008, Shawn O. Pearce <spearce@spearce.org>
   3  *
   4  * All rights reserved.
   5  *
   6  * Redistribution and use in source and binary forms, with or
   7  * without modification, are permitted provided that the following
   8  * conditions are met:
   9  *
  10  * - Redistributions of source code must retain the above copyright
  11  *   notice, this list of conditions and the following disclaimer.
  12  *
  13  * - Redistributions in binary form must reproduce the above
  14  *   copyright notice, this list of conditions and the following
  15  *   disclaimer in the documentation and/or other materials provided
  16  *   with the distribution.
  17  *
  18  * - Neither the name of the Git Development Community nor the
  19  *   names of its contributors may be used to endorse or promote
  20  *   products derived from this software without specific prior
  21  *   written permission.
  22  *
  23  * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND
  24  * CONTRIBUTORS "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES,
  25  * INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
  26  * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  27  * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR
  28  * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
  29  * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
  30  * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
  31  * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
  32  * CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
  33  * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
  34  * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF
  35  * ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  36  */
  37
  38 package org.spearce.jgit.revwalk;
  39
  40 import java.io.IOException;
  41
  42 import org.spearce.jgit.errors.IncorrectObjectTypeException;
  43 import org.spearce.jgit.errors.MissingObjectException;
  44
  45 /** A queue of commits in FIFO order. */
  46 public class FIFORevQueue extends BlockRevQueue {
  47         private Block head;
  48
  49         private Block tail;
  50
  51         /** Create an empty FIFO queue. */
  52         public FIFORevQueue() {
  53                 super();
  54         }
  55
  56         FIFORevQueue(final Generator s) throws MissingObjectException,
  57                         IncorrectObjectTypeException, IOException {
  58                 super(s);
  59         }
  60
  61         public void add(final RevCommit c) {
  62                 Block b = tail;
  63                 if (b == null) {
  64                         b = free.newBlock();
  65                         b.add(c);
  66                         head = b;
  67                         tail = b;
  68                         return;
  69                 } else if (b.isFull()) {
  70                         b = free.newBlock();
  71                         tail.next = b;
  72                         tail = b;
  73                 }
  74                 b.add(c);
  75         }
  76
  77         /**
  78          * Insert the commit pointer at the front of the queue.
  79          *
  80          * @param c
  81          *            the commit to insert into the queue.
  82          */
  83         public void unpop(final RevCommit c) {
  84                 Block b = head;
  85                 if (b == null) {
  86                         b = free.newBlock();
  87                         b.resetToMiddle();
  88                         b.add(c);
  89                         head = b;
  90                         tail = b;
  91                         return;
  92                 } else if (b.canUnpop()) {
  93                         b.unpop(c);
  94                         return;
  95                 }
  96
  97                 b = free.newBlock();
  98                 b.resetToEnd();
  99                 b.unpop(c);
 100                 b.next = head;
 101                 head = b;
 102         }
 103
 104         public RevCommit next() {
 105                 final Block b = head;
 106                 if (b == null)
 107                         return null;
 108
 109                 final RevCommit c = b.pop();
 110                 if (b.isEmpty()) {
 111                         head = b.next;
 112                         if (head == null)
 113                                 tail = null;
 114                         free.freeBlock(b);
 115                 }
 116                 return c;
 117         }
 118
 119         public void clear() {
 120                 head = null;
 121                 tail = null;
 122                 free.clear();
 123         }
 124
 125         boolean everbodyHasFlag(final int f) {
 126                 for (Block b = head; b != null; b = b.next) {
 127                         for (int i = b.headIndex; i < b.tailIndex; i++)
 128                                 if ((b.commits[i].flags & f) == 0)
 129                                         return false;
 130                 }
 131                 return true;
 132         }
 133
 134         boolean anybodyHasFlag(final int f) {
 135                 for (Block b = head; b != null; b = b.next) {
 136                         for (int i = b.headIndex; i < b.tailIndex; i++)
 137                                 if ((b.commits[i].flags & f) != 0)
 138                                         return true;
 139                 }
 140                 return false;
 141         }
 142
 143         void removeFlag(final int f) {
 144                 final int not_f = ~f;
 145                 for (Block b = head; b != null; b = b.next) {
 146                         for (int i = b.headIndex; i < b.tailIndex; i++)
 147                                 b.commits[i].flags &= not_f;
 148                 }
 149         }
 150
 151         public String toString() {
 152                 final StringBuffer s = new StringBuffer();
 153                 for (Block q = head; q != null; q = q.next) {
 154                         for (int i = q.headIndex; i < q.tailIndex; i++) {
 155                                 s.append(q.commits[i]);
 156                                 s.append(' ');
 157                                 s.append(q.commits[i].commitTime);
 158                                 s.append('\n');
 159                         }
 160                 }
 161                 return s.toString();
 162         }
 163 }