mirror of
https://github.com/mozilla/gecko-dev.git
synced 2024-11-08 20:47:44 +00:00
289 lines
8.9 KiB
C++
289 lines
8.9 KiB
C++
/* -*- 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 ***** */
|
|
|
|
#ifndef nsTArray_h__
|
|
# error "Don't include this file directly"
|
|
#endif
|
|
|
|
template<class Alloc>
|
|
nsTArray_base<Alloc>::nsTArray_base()
|
|
: mHdr(EmptyHdr()) {
|
|
MOZ_COUNT_CTOR(nsTArray_base);
|
|
}
|
|
|
|
template<class Alloc>
|
|
nsTArray_base<Alloc>::~nsTArray_base() {
|
|
if (mHdr != EmptyHdr() && !UsesAutoArrayBuffer()) {
|
|
Alloc::Free(mHdr);
|
|
}
|
|
MOZ_COUNT_DTOR(nsTArray_base);
|
|
}
|
|
|
|
template<class Alloc>
|
|
PRBool
|
|
nsTArray_base<Alloc>::EnsureCapacity(size_type capacity, size_type elemSize) {
|
|
// This should be the most common case so test this first
|
|
if (capacity <= mHdr->mCapacity)
|
|
return PR_TRUE;
|
|
|
|
// If the requested memory allocation exceeds size_type(-1)/2, then
|
|
// our doubling algorithm may not be able to allocate it.
|
|
// Additionally we couldn't fit in the Header::mCapacity
|
|
// member. 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 == EmptyHdr()) {
|
|
// Malloc() new data
|
|
Header *header = static_cast<Header*>
|
|
(Alloc::Malloc(sizeof(Header) + capacity * elemSize));
|
|
if (!header)
|
|
return PR_FALSE;
|
|
header->mLength = 0;
|
|
header->mCapacity = capacity;
|
|
header->mIsAutoArray = 0;
|
|
mHdr = header;
|
|
|
|
return PR_TRUE;
|
|
}
|
|
|
|
// Use doubling algorithm when forced to increase available
|
|
// capacity. (Note that mCapacity is only 31 bits wide, so
|
|
// multiplication promotes its type. We use |2u| instead of |2|
|
|
// to make sure it's promoted to unsigned.)
|
|
capacity = PR_MAX(capacity, mHdr->mCapacity * 2u);
|
|
|
|
Header *header;
|
|
if (UsesAutoArrayBuffer()) {
|
|
// Malloc() and copy
|
|
header = static_cast<Header*>
|
|
(Alloc::Malloc(sizeof(Header) + capacity * elemSize));
|
|
if (!header)
|
|
return PR_FALSE;
|
|
|
|
memcpy(header, mHdr, sizeof(Header) + Length() * elemSize);
|
|
} else {
|
|
// Realloc() existing data
|
|
size_type size = sizeof(Header) + capacity * elemSize;
|
|
header = static_cast<Header*>(Alloc::Realloc(mHdr, size));
|
|
if (!header)
|
|
return PR_FALSE;
|
|
}
|
|
|
|
header->mCapacity = capacity;
|
|
mHdr = header;
|
|
|
|
return PR_TRUE;
|
|
}
|
|
|
|
template<class Alloc>
|
|
void
|
|
nsTArray_base<Alloc>::ShrinkCapacity(size_type elemSize) {
|
|
if (mHdr == EmptyHdr() || UsesAutoArrayBuffer())
|
|
return;
|
|
|
|
if (mHdr->mLength >= mHdr->mCapacity) // should never be greater than...
|
|
return;
|
|
|
|
size_type length = Length();
|
|
|
|
if (IsAutoArray() && GetAutoArrayBuffer()->mCapacity >= length) {
|
|
Header* header = GetAutoArrayBuffer();
|
|
|
|
// Copy data, but don't copy the header to avoid overwriting mCapacity
|
|
header->mLength = length;
|
|
memcpy(header + 1, mHdr + 1, length * elemSize);
|
|
|
|
Alloc::Free(mHdr);
|
|
mHdr = header;
|
|
return;
|
|
}
|
|
|
|
if (length == 0) {
|
|
NS_ASSERTION(!IsAutoArray(), "autoarray should have fit 0 elements");
|
|
Alloc::Free(mHdr);
|
|
mHdr = EmptyHdr();
|
|
return;
|
|
}
|
|
|
|
size_type size = sizeof(Header) + length * elemSize;
|
|
void *ptr = Alloc::Realloc(mHdr, size);
|
|
if (!ptr)
|
|
return;
|
|
mHdr = static_cast<Header*>(ptr);
|
|
mHdr->mCapacity = length;
|
|
}
|
|
|
|
template<class Alloc>
|
|
void
|
|
nsTArray_base<Alloc>::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 = reinterpret_cast<char*>(mHdr + 1) + start;
|
|
memmove(base + newLen, base + oldLen, num);
|
|
}
|
|
}
|
|
|
|
template<class Alloc>
|
|
PRBool
|
|
nsTArray_base<Alloc>::InsertSlotsAt(index_type index, size_type count,
|
|
size_type elementSize) {
|
|
NS_ASSERTION(index <= Length(), "Bogus insertion index");
|
|
size_type newLen = Length() + count;
|
|
|
|
EnsureCapacity(newLen, elementSize);
|
|
|
|
// Check for out of memory conditions
|
|
if (Capacity() < newLen)
|
|
return PR_FALSE;
|
|
|
|
// Move the existing elements as needed. Note that this will
|
|
// change our mLength, so no need to call IncrementLength.
|
|
ShiftData(index, 0, count, elementSize);
|
|
|
|
return PR_TRUE;
|
|
}
|
|
|
|
template<class Alloc>
|
|
template<class Allocator>
|
|
PRBool
|
|
nsTArray_base<Alloc>::SwapArrayElements(nsTArray_base<Allocator>& other,
|
|
size_type elemSize) {
|
|
#ifdef DEBUG
|
|
PRBool isAuto = IsAutoArray();
|
|
PRBool otherIsAuto = other.IsAutoArray();
|
|
#endif
|
|
|
|
if (!EnsureNotUsingAutoArrayBuffer(elemSize) ||
|
|
!other.EnsureNotUsingAutoArrayBuffer(elemSize)) {
|
|
return PR_FALSE;
|
|
}
|
|
|
|
NS_ASSERTION(isAuto == IsAutoArray(), "lost auto info");
|
|
NS_ASSERTION(otherIsAuto == other.IsAutoArray(), "lost auto info");
|
|
NS_ASSERTION(!UsesAutoArrayBuffer() && !other.UsesAutoArrayBuffer(),
|
|
"both should be using an alloced buffer now");
|
|
|
|
// If the two arrays have different mIsAutoArray values (i.e. one is
|
|
// an autoarray and one is not) then simply switching the buffers is
|
|
// going to make that bit wrong. We therefore adjust these
|
|
// mIsAutoArray bits before switching the buffers so that once the
|
|
// buffers are switched the mIsAutoArray bits are right again.
|
|
// However, we have to watch out so that we don't set the bit on
|
|
// sEmptyHeader. If an array (A) uses the empty header (and the
|
|
// other (B) therefore must be an nsAutoTArray) we make A point to
|
|
// the B's autobuffer so that when the buffers are switched B points
|
|
// to its own autobuffer.
|
|
|
|
// Adjust mIsAutoArray flags before swapping the buffers
|
|
if (IsAutoArray() && !other.IsAutoArray()) {
|
|
if (other.mHdr == EmptyHdr()) {
|
|
// Set other to use our built-in buffer so that we use it
|
|
// after the swap below.
|
|
other.mHdr = GetAutoArrayBuffer();
|
|
other.mHdr->mLength = 0;
|
|
}
|
|
else {
|
|
other.mHdr->mIsAutoArray = 1;
|
|
}
|
|
mHdr->mIsAutoArray = 0;
|
|
}
|
|
else if (!IsAutoArray() && other.IsAutoArray()) {
|
|
if (mHdr == EmptyHdr()) {
|
|
// Set us to use other's built-in buffer so that other use it
|
|
// after the swap below.
|
|
mHdr = other.GetAutoArrayBuffer();
|
|
mHdr->mLength = 0;
|
|
}
|
|
else {
|
|
mHdr->mIsAutoArray = 1;
|
|
}
|
|
other.mHdr->mIsAutoArray = 0;
|
|
}
|
|
|
|
// Swap the buffers
|
|
Header *h = other.mHdr;
|
|
other.mHdr = mHdr;
|
|
mHdr = h;
|
|
|
|
NS_ASSERTION(isAuto == IsAutoArray(), "lost auto info");
|
|
NS_ASSERTION(otherIsAuto == other.IsAutoArray(), "lost auto info");
|
|
|
|
return PR_TRUE;
|
|
}
|
|
|
|
template<class Alloc>
|
|
PRBool
|
|
nsTArray_base<Alloc>::EnsureNotUsingAutoArrayBuffer(size_type elemSize) {
|
|
if (UsesAutoArrayBuffer()) {
|
|
size_type size = sizeof(Header) + Length() * elemSize;
|
|
|
|
Header* header = static_cast<Header*>(Alloc::Malloc(size));
|
|
if (!header)
|
|
return PR_FALSE;
|
|
|
|
memcpy(header, mHdr, size);
|
|
header->mCapacity = Length();
|
|
mHdr = header;
|
|
}
|
|
|
|
return PR_TRUE;
|
|
}
|