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/* -*- 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;
}
#ifdef 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
////////////////////////////////////////////////////////////////////////////////
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