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

Mercurial (5216dd412535)

VCS Links

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 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 161 162 163 164 165 166 167 168 169 170 171 172 173 174 175 176 177 178 179 180 181 182 183 184 185 186 187 188 189 190 191 192 193 194 195 196 197 198 199 200 201 202 203 204 205 206 207
/* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 4 -*- */
/* ***** 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 mozilla.org code.
 *
 * The Initial Developer of the Original Code is
 * Netscape Communications Corporation.
 * Portions created by the Initial Developer are Copyright (C) 1998
 * the Initial Developer. All Rights Reserved.
 *
 * Contributor(s):
 *
 * Alternatively, the contents of this file may be used under the terms of
 * either of 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 "nsSegmentedBuffer.h"
#include "nsCRT.h"

nsresult
nsSegmentedBuffer::Init(PRUint32 segmentSize, PRUint32 maxSize,
                        nsIMemory* allocator)
{
    if (mSegmentArrayCount != 0)
        return NS_ERROR_FAILURE;        // initialized more than once
    mSegmentSize = segmentSize;
    mMaxSize = maxSize;
    mSegAllocator = allocator;
    if (mSegAllocator == nsnull) {
        mSegAllocator = nsMemory::GetGlobalMemoryService();
    }
    else {
        NS_ADDREF(mSegAllocator);
    }
#if 0 // testing...
    mSegmentArrayCount = 2;
#else
    mSegmentArrayCount = NS_SEGMENTARRAY_INITIAL_COUNT;
#endif
    return NS_OK;
}

char*
nsSegmentedBuffer::AppendNewSegment()
{
    if (GetSize() >= mMaxSize)
        return nsnull;

    if (mSegmentArray == nsnull) {
        PRUint32 bytes = mSegmentArrayCount * sizeof(char*);
        mSegmentArray = (char**)nsMemory::Alloc(bytes);
        if (mSegmentArray == nsnull)
            return nsnull;
        memset(mSegmentArray, 0, bytes);
    }
    
    if (IsFull()) {
        PRUint32 newArraySize = mSegmentArrayCount * 2;
        PRUint32 bytes = newArraySize * sizeof(char*);
        char** newSegArray = (char**)nsMemory::Realloc(mSegmentArray, bytes);
        if (newSegArray == nsnull)
            return nsnull;
        mSegmentArray = newSegArray;
        // copy wrapped content to new extension
        if (mFirstSegmentIndex > mLastSegmentIndex) {
            // deal with wrap around case
            memcpy(&mSegmentArray[mSegmentArrayCount],
                   mSegmentArray,
                   mLastSegmentIndex * sizeof(char*));
            memset(mSegmentArray, 0, mLastSegmentIndex * sizeof(char*));
            mLastSegmentIndex += mSegmentArrayCount;
            memset(&mSegmentArray[mLastSegmentIndex], 0,
                   (newArraySize - mLastSegmentIndex) * sizeof(char*));
        }
        else {
            memset(&mSegmentArray[mLastSegmentIndex], 0,
                   (newArraySize - mLastSegmentIndex) * sizeof(char*));
        }
        mSegmentArrayCount = newArraySize;
    }

    char* seg = (char*)mSegAllocator->Alloc(mSegmentSize);
    if (seg == nsnull) {
        return nsnull;
    }
    mSegmentArray[mLastSegmentIndex] = seg;
    mLastSegmentIndex = ModSegArraySize(mLastSegmentIndex + 1);
    return seg;
}

PRBool
nsSegmentedBuffer::DeleteFirstSegment()
{
    NS_ASSERTION(mSegmentArray[mFirstSegmentIndex] != nsnull, "deleting bad segment");
    (void)mSegAllocator->Free(mSegmentArray[mFirstSegmentIndex]);
    mSegmentArray[mFirstSegmentIndex] = nsnull;
    PRInt32 last = ModSegArraySize(mLastSegmentIndex - 1);
    if (mFirstSegmentIndex == last) {
        mLastSegmentIndex = last;
        return PR_TRUE;
    }
    else {
        mFirstSegmentIndex = ModSegArraySize(mFirstSegmentIndex + 1);
        return PR_FALSE;
    }
}

PRBool
nsSegmentedBuffer::DeleteLastSegment()
{
    PRInt32 last = ModSegArraySize(mLastSegmentIndex - 1);
    NS_ASSERTION(mSegmentArray[last] != nsnull, "deleting bad segment");
    (void)mSegAllocator->Free(mSegmentArray[last]);
    mSegmentArray[last] = nsnull;
    mLastSegmentIndex = last;
    return (PRBool)(mLastSegmentIndex == mFirstSegmentIndex);
}

PRBool
nsSegmentedBuffer::ReallocLastSegment(size_t newSize)
{
    PRInt32 last = ModSegArraySize(mLastSegmentIndex - 1);
    NS_ASSERTION(mSegmentArray[last] != nsnull, "realloc'ing bad segment");
    char *newSegment =
        (char*)mSegAllocator->Realloc(mSegmentArray[last], newSize);
    if (newSegment) {
        mSegmentArray[last] = newSegment;
        return PR_TRUE;
    } else {
        return PR_FALSE;
    }
}

void
nsSegmentedBuffer::Empty()
{
    if (mSegmentArray) {
        for (PRUint32 i = 0; i < mSegmentArrayCount; i++) {
            if (mSegmentArray[i])
                mSegAllocator->Free(mSegmentArray[i]);
        }
        nsMemory::Free(mSegmentArray);
        mSegmentArray = nsnull;
    }
    mSegmentArrayCount = NS_SEGMENTARRAY_INITIAL_COUNT;
    mFirstSegmentIndex = mLastSegmentIndex = 0;
}

#if !defined(MOZ_ENABLE_LIBXUL) && defined(DEBUG)
NS_COM void
TestSegmentedBuffer()
{
    nsSegmentedBuffer* buf = new nsSegmentedBuffer();
    NS_ASSERTION(buf, "out of memory");
    buf->Init(4, 16);
    char* seg;
    PRBool empty;
    seg = buf->AppendNewSegment();
    NS_ASSERTION(seg, "AppendNewSegment failed");
    seg = buf->AppendNewSegment();
    NS_ASSERTION(seg, "AppendNewSegment failed");
    seg = buf->AppendNewSegment();
    NS_ASSERTION(seg, "AppendNewSegment failed");
    empty = buf->DeleteFirstSegment();
    NS_ASSERTION(!empty, "DeleteFirstSegment failed");
    empty = buf->DeleteFirstSegment();
    NS_ASSERTION(!empty, "DeleteFirstSegment failed");
    seg = buf->AppendNewSegment();
    NS_ASSERTION(seg, "AppendNewSegment failed");
    seg = buf->AppendNewSegment();
    NS_ASSERTION(seg, "AppendNewSegment failed");
    seg = buf->AppendNewSegment();
    NS_ASSERTION(seg, "AppendNewSegment failed");
    empty = buf->DeleteFirstSegment();
    NS_ASSERTION(!empty, "DeleteFirstSegment failed");
    empty = buf->DeleteFirstSegment();
    NS_ASSERTION(!empty, "DeleteFirstSegment failed");
    empty = buf->DeleteFirstSegment();
    NS_ASSERTION(!empty, "DeleteFirstSegment failed");
    empty = buf->DeleteFirstSegment();
    NS_ASSERTION(empty, "DeleteFirstSegment failed");
    delete buf;
}
#endif

////////////////////////////////////////////////////////////////////////////////