DXR is a code search and navigation tool aimed at making sense of large projects. It supports full-text and regex searches as well as structural queries.

Header

Untracked file

Line Code
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134
/* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
/* vim:set ts=2 sw=2 sts=2 et cindent: */
/* ***** BEGIN LICENSE BLOCK *****
 * Version: MPL 1.1/GPL 2.0/LGPL 2.1
 *
 * The contents of this file are subject to the Mozilla Public License Version
 * 1.1 (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.mozilla.org/MPL/
 *
 * Software distributed under the License is distributed on an "AS IS" basis,
 * WITHOUT WARRANTY OF ANY KIND, either express or implied. See the License
 * for the specific language governing rights and limitations under the
 * License.
 *
 * The Original Code is C++ array template.
 *
 * The Initial Developer of the Original Code is Google Inc.
 * Portions created by the Initial Developer are Copyright (C) 2005
 * the Initial Developer. All Rights Reserved.
 *
 * Contributor(s):
 *  Darin Fisher <darin@meer.net>
 *
 * Alternatively, the contents of this file may be used under the terms of
 * either the GNU General Public License Version 2 or later (the "GPL"), or
 * the GNU Lesser General Public License Version 2.1 or later (the "LGPL"),
 * in which case the provisions of the GPL or the LGPL are applicable instead
 * of those above. If you wish to allow use of your version of this file only
 * under the terms of either the GPL or the LGPL, and not to allow others to
 * use your version of this file under the terms of the MPL, indicate your
 * decision by deleting the provisions above and replace them with the notice
 * and other provisions required by the GPL or the LGPL. If you do not delete
 * the provisions above, a recipient may use your version of this file under
 * the terms of any one of the MPL, the GPL or the LGPL.
 *
 * ***** END LICENSE BLOCK ***** */

#include <string.h>
#include "nsTArray.h"
#include "nsXPCOM.h"
#include "nsDebug.h"

const nsTArray_base::Header nsTArray_base::sEmptyHdr = { 0, 0 };

PRBool
nsTArray_base::EnsureCapacity(size_type capacity, size_type elemSize) {
  // If the requested memory allocation exceeds size_type(-1)/2, then our
  // doubling algorithm may not be able to allocate it.  Just bail out in
  // cases like that.  We don't want to be allocating 2 GB+ arrays anyway.
  if ((PRUint64)capacity * elemSize > size_type(-1)/2) {
    NS_ERROR("Attempting to allocate excessively large array");
    return PR_FALSE;
  }
  if (mHdr == &sEmptyHdr) {
    // NS_Alloc new data
    Header *header = NS_STATIC_CAST(Header*,
                         NS_Alloc(sizeof(Header) + capacity * elemSize));
    if (!header)
      return PR_FALSE;
    header->mLength = 0;
    header->mCapacity = capacity;
    mHdr = header;
  } else {
    // NS_Realloc existing data
    if (capacity <= mHdr->mCapacity)
      return PR_TRUE;

    // Use doubling algorithm when forced to increase available capacity.
    if (mHdr->mCapacity > 0) {
      size_type temp = mHdr->mCapacity;
      while (temp < capacity)
        temp <<= 1;
      capacity = temp;
    }

    size_type size = sizeof(Header) + capacity * elemSize;
    void *ptr = NS_Realloc(mHdr, size);
    if (!ptr)
      return PR_FALSE;
    mHdr = NS_STATIC_CAST(Header*, ptr);
    mHdr->mCapacity = capacity;
  }
  return PR_TRUE;
}

void
nsTArray_base::ShrinkCapacity(size_type elemSize) {
  if (mHdr == &sEmptyHdr)
    return;

  if (mHdr->mLength >= mHdr->mCapacity)  // should never be greater than...
    return;

  if (mHdr->mLength == 0) {
    NS_Free(mHdr);
    mHdr = NS_CONST_CAST(Header *, &sEmptyHdr);
    return;
  }

  size_type size = sizeof(Header) + mHdr->mLength * elemSize;
  void *ptr = NS_Realloc(mHdr, size);
  if (!ptr)
    return;
  mHdr = NS_STATIC_CAST(Header*, ptr);
  mHdr->mCapacity = mHdr->mLength;
}

void
nsTArray_base::ShiftData(index_type start, size_type oldLen, size_type newLen,
                         size_type elemSize) {
  if (oldLen == newLen)
    return;

  // Determine how many elements need to be shifted
  size_type num = mHdr->mLength - (start + oldLen);

  // Compute the resulting length of the array
  mHdr->mLength += newLen - oldLen;
  if (mHdr->mLength == 0) {
    ShrinkCapacity(elemSize);
  } else {
    // Maybe nothing needs to be shifted
    if (num == 0)
      return;
    // Perform shift (change units to bytes first)
    start *= elemSize;
    newLen *= elemSize;
    oldLen *= elemSize;
    num *= elemSize;
    char *base = NS_REINTERPRET_CAST(char*, mHdr + 1) + start;
    memmove(base + newLen, base + oldLen, num);
  }
}