ACPR/android_system_core
1
0
Fork 0
Code Issues Pull requests Projects Releases Packages Wiki Activity Actions
android_system_core/libs/utils/VectorImpl.cpp
Jeff Brown aa5daede6a Replace Vector _grow/_shrink checks with assert. 
On review of the code, _grow and _shrink are checking for conditions
that cannot happen and that don't even really make sense.  For
example, if _shrink is called with where + amount > mCount then
this is really bad, however the check only considered the case
when where >= mCount and then it would arbitrarily choose a new
value for where.  Huh?

As it happens, the callers are correctly validating the
arguments before passing them down to these methods so we can
get rid of this code.

Change-Id: I921852dba8997065bb0e9cac733e82028d14afcd
2013-07-30 13:56:57 -07:00

626 lines
18 KiB
C++
Raw Blame History

/*
* Copyright (C) 2005 The Android Open Source Project
*
* Licensed under the Apache License, Version 2.0 (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.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
#define LOG_TAG "Vector"
#include <string.h>
#include <stdlib.h>
#include <stdio.h>
#include <utils/Log.h>
#include <utils/Errors.h>
#include <utils/SharedBuffer.h>
#include <utils/VectorImpl.h>
/*****************************************************************************/
namespace android {
// ----------------------------------------------------------------------------
const size_t kMinVectorCapacity = 4;
static inline size_t max(size_t a, size_t b) {
return a>b ? a : b;
}
// ----------------------------------------------------------------------------
VectorImpl::VectorImpl(size_t itemSize, uint32_t flags)
: mStorage(0), mCount(0), mFlags(flags), mItemSize(itemSize)
{
}
VectorImpl::VectorImpl(const VectorImpl& rhs)
: mStorage(rhs.mStorage), mCount(rhs.mCount),
mFlags(rhs.mFlags), mItemSize(rhs.mItemSize)
{
if (mStorage) {
SharedBuffer::sharedBuffer(mStorage)->acquire();
}
}
VectorImpl::~VectorImpl()
{
LOG_ASSERT(!mCount,
"[%p] "
"subclasses of VectorImpl must call finish_vector()"
" in their destructor. Leaking %d bytes.",
this, (int)(mCount*mItemSize));
// We can't call _do_destroy() here because the vtable is already gone.
}
VectorImpl& VectorImpl::operator = (const VectorImpl& rhs)
{
LOG_ASSERT(mItemSize == rhs.mItemSize,
"Vector<> have different types (this=%p, rhs=%p)", this, &rhs);
if (this != &rhs) {
release_storage();
if (rhs.mCount) {
mStorage = rhs.mStorage;
mCount = rhs.mCount;
SharedBuffer::sharedBuffer(mStorage)->acquire();
} else {
mStorage = 0;
mCount = 0;
}
}
return *this;
}
void* VectorImpl::editArrayImpl()
{
if (mStorage) {
SharedBuffer* sb = SharedBuffer::sharedBuffer(mStorage)->attemptEdit();
if (sb == 0) {
sb = SharedBuffer::alloc(capacity() * mItemSize);
if (sb) {
_do_copy(sb->data(), mStorage, mCount);
release_storage();
mStorage = sb->data();
}
}
}
return mStorage;
}
size_t VectorImpl::capacity() const
{
if (mStorage) {
return SharedBuffer::sharedBuffer(mStorage)->size() / mItemSize;
}
return 0;
}
ssize_t VectorImpl::insertVectorAt(const VectorImpl& vector, size_t index)
{
return insertArrayAt(vector.arrayImpl(), index, vector.size());
}
ssize_t VectorImpl::appendVector(const VectorImpl& vector)
{
return insertVectorAt(vector, size());
}
ssize_t VectorImpl::insertArrayAt(const void* array, size_t index, size_t length)
{
if (index > size())
return BAD_INDEX;
void* where = _grow(index, length);
if (where) {
_do_copy(where, array, length);
}
return where ? index : (ssize_t)NO_MEMORY;
}
ssize_t VectorImpl::appendArray(const void* array, size_t length)
{
return insertArrayAt(array, size(), length);
}
ssize_t VectorImpl::insertAt(size_t index, size_t numItems)
{
return insertAt(0, index, numItems);
}
ssize_t VectorImpl::insertAt(const void* item, size_t index, size_t numItems)
{
if (index > size())
return BAD_INDEX;
void* where = _grow(index, numItems);
if (where) {
if (item) {
_do_splat(where, item, numItems);
} else {
_do_construct(where, numItems);
}
}
return where ? index : (ssize_t)NO_MEMORY;
}
static int sortProxy(const void* lhs, const void* rhs, void* func)
{
return (*(VectorImpl::compar_t)func)(lhs, rhs);
}
status_t VectorImpl::sort(VectorImpl::compar_t cmp)
{
return sort(sortProxy, (void*)cmp);
}
status_t VectorImpl::sort(VectorImpl::compar_r_t cmp, void* state)
{
// the sort must be stable. we're using insertion sort which
// is well suited for small and already sorted arrays
// for big arrays, it could be better to use mergesort
const ssize_t count = size();
if (count > 1) {
void* array = const_cast<void*>(arrayImpl());
void* temp = 0;
ssize_t i = 1;
while (i < count) {
void* item = reinterpret_cast<char*>(array) + mItemSize*(i);
void* curr = reinterpret_cast<char*>(array) + mItemSize*(i-1);
if (cmp(curr, item, state) > 0) {
if (!temp) {
// we're going to have to modify the array...
array = editArrayImpl();
if (!array) return NO_MEMORY;
temp = malloc(mItemSize);
if (!temp) return NO_MEMORY;
item = reinterpret_cast<char*>(array) + mItemSize*(i);
curr = reinterpret_cast<char*>(array) + mItemSize*(i-1);
} else {
_do_destroy(temp, 1);
}
_do_copy(temp, item, 1);
ssize_t j = i-1;
void* next = reinterpret_cast<char*>(array) + mItemSize*(i);
do {
_do_destroy(next, 1);
_do_copy(next, curr, 1);
next = curr;
--j;
curr = reinterpret_cast<char*>(array) + mItemSize*(j);
} while (j>=0 && (cmp(curr, temp, state) > 0));
_do_destroy(next, 1);
_do_copy(next, temp, 1);
}
i++;
}
if (temp) {
_do_destroy(temp, 1);
free(temp);
}
}
return NO_ERROR;
}
void VectorImpl::pop()
{
if (size())
removeItemsAt(size()-1, 1);
}
void VectorImpl::push()
{
push(0);
}
void VectorImpl::push(const void* item)
{
insertAt(item, size());
}
ssize_t VectorImpl::add()
{
return add(0);
}
ssize_t VectorImpl::add(const void* item)
{
return insertAt(item, size());
}
ssize_t VectorImpl::replaceAt(size_t index)
{
return replaceAt(0, index);
}
ssize_t VectorImpl::replaceAt(const void* prototype, size_t index)
{
LOG_ASSERT(index<size(),
"[%p] replace: index=%d, size=%d", this, (int)index, (int)size());
void* item = editItemLocation(index);
if (item == 0)
return NO_MEMORY;
_do_destroy(item, 1);
if (prototype == 0) {
_do_construct(item, 1);
} else {
_do_copy(item, prototype, 1);
}
return ssize_t(index);
}
ssize_t VectorImpl::removeItemsAt(size_t index, size_t count)
{
LOG_ASSERT((index+count)<=size(),
"[%p] remove: index=%d, count=%d, size=%d",
this, (int)index, (int)count, (int)size());
if ((index+count) > size())
return BAD_VALUE;
_shrink(index, count);
return index;
}
void VectorImpl::finish_vector()
{
release_storage();
mStorage = 0;
mCount = 0;
}
void VectorImpl::clear()
{
_shrink(0, mCount);
}
void* VectorImpl::editItemLocation(size_t index)
{
LOG_ASSERT(index<capacity(),
"[%p] editItemLocation: index=%d, capacity=%d, count=%d",
this, (int)index, (int)capacity(), (int)mCount);
void* buffer = editArrayImpl();
if (buffer)
return reinterpret_cast<char*>(buffer) + index*mItemSize;
return 0;
}
const void* VectorImpl::itemLocation(size_t index) const
{
LOG_ASSERT(index<capacity(),
"[%p] itemLocation: index=%d, capacity=%d, count=%d",
this, (int)index, (int)capacity(), (int)mCount);
const void* buffer = arrayImpl();
if (buffer)
return reinterpret_cast<const char*>(buffer) + index*mItemSize;
return 0;
}
ssize_t VectorImpl::setCapacity(size_t new_capacity)
{
size_t current_capacity = capacity();
ssize_t amount = new_capacity - size();
if (amount <= 0) {
// we can't reduce the capacity
return current_capacity;
}
SharedBuffer* sb = SharedBuffer::alloc(new_capacity * mItemSize);
if (sb) {
void* array = sb->data();
_do_copy(array, mStorage, size());
release_storage();
mStorage = const_cast<void*>(array);
} else {
return NO_MEMORY;
}
return new_capacity;
}
void VectorImpl::release_storage()
{
if (mStorage) {
const SharedBuffer* sb = SharedBuffer::sharedBuffer(mStorage);
if (sb->release(SharedBuffer::eKeepStorage) == 1) {
_do_destroy(mStorage, mCount);
SharedBuffer::dealloc(sb);
}
}
}
void* VectorImpl::_grow(size_t where, size_t amount)
{
// LOGV("_grow(this=%p, where=%d, amount=%d) count=%d, capacity=%d",
// this, (int)where, (int)amount, (int)mCount, (int)capacity());
LOG_ASSERT(where <= mCount,
"[%p] _grow: where=%d, amount=%d, count=%d",
this, (int)where, (int)amount, (int)mCount); // caller already checked
const size_t new_size = mCount + amount;
if (capacity() < new_size) {
const size_t new_capacity = max(kMinVectorCapacity, ((new_size*3)+1)/2);
// LOGV("grow vector %p, new_capacity=%d", this, (int)new_capacity);
if ((mStorage) &&
(mCount==where) &&
(mFlags & HAS_TRIVIAL_COPY) &&
(mFlags & HAS_TRIVIAL_DTOR))
{
const SharedBuffer* cur_sb = SharedBuffer::sharedBuffer(mStorage);
SharedBuffer* sb = cur_sb->editResize(new_capacity * mItemSize);
mStorage = sb->data();
} else {
SharedBuffer* sb = SharedBuffer::alloc(new_capacity * mItemSize);
if (sb) {
void* array = sb->data();
if (where>0) {
_do_copy(array, mStorage, where);
}
if (mCount>where) {
const void* from = reinterpret_cast<const uint8_t *>(mStorage) + where*mItemSize;
void* dest = reinterpret_cast<uint8_t *>(array) + (where+amount)*mItemSize;
_do_copy(dest, from, mCount-where);
}
release_storage();
mStorage = const_cast<void*>(array);
}
}
} else {
ssize_t s = mCount-where;
if (s>0) {
void* array = editArrayImpl();
void* to = reinterpret_cast<uint8_t *>(array) + (where+amount)*mItemSize;
const void* from = reinterpret_cast<const uint8_t *>(array) + where*mItemSize;
_do_move_forward(to, from, s);
}
}
mCount += amount;
void* free_space = const_cast<void*>(itemLocation(where));
return free_space;
}
void VectorImpl::_shrink(size_t where, size_t amount)
{
if (!mStorage)
return;
// LOGV("_shrink(this=%p, where=%d, amount=%d) count=%d, capacity=%d",
// this, (int)where, (int)amount, (int)mCount, (int)capacity());
LOG_ASSERT(where + amount <= mCount,
"[%p] _shrink: where=%d, amount=%d, count=%d",
this, (int)where, (int)amount, (int)mCount); // caller already checked
const size_t new_size = mCount - amount;
if (new_size*3 < capacity()) {
const size_t new_capacity = max(kMinVectorCapacity, new_size*2);
// LOGV("shrink vector %p, new_capacity=%d", this, (int)new_capacity);
if ((where == mCount-amount) &&
(mFlags & HAS_TRIVIAL_COPY) &&
(mFlags & HAS_TRIVIAL_DTOR))
{
const SharedBuffer* cur_sb = SharedBuffer::sharedBuffer(mStorage);
SharedBuffer* sb = cur_sb->editResize(new_capacity * mItemSize);
mStorage = sb->data();
} else {
SharedBuffer* sb = SharedBuffer::alloc(new_capacity * mItemSize);
if (sb) {
void* array = sb->data();
if (where>0) {
_do_copy(array, mStorage, where);
}
if (mCount > where+amount) {
const void* from = reinterpret_cast<const uint8_t *>(mStorage) + (where+amount)*mItemSize;
void* dest = reinterpret_cast<uint8_t *>(array) + where*mItemSize;
_do_copy(dest, from, mCount-(where+amount));
}
release_storage();
mStorage = const_cast<void*>(array);
}
}
} else {
void* array = editArrayImpl();
void* to = reinterpret_cast<uint8_t *>(array) + where*mItemSize;
_do_destroy(to, amount);
ssize_t s = mCount-(where+amount);
if (s>0) {
const void* from = reinterpret_cast<uint8_t *>(array) + (where+amount)*mItemSize;
_do_move_backward(to, from, s);
}
}
// adjust the number of items...
mCount -= amount;
}
size_t VectorImpl::itemSize() const {
return mItemSize;
}
void VectorImpl::_do_construct(void* storage, size_t num) const
{
if (!(mFlags & HAS_TRIVIAL_CTOR)) {
do_construct(storage, num);
}
}
void VectorImpl::_do_destroy(void* storage, size_t num) const
{
if (!(mFlags & HAS_TRIVIAL_DTOR)) {
do_destroy(storage, num);
}
}
void VectorImpl::_do_copy(void* dest, const void* from, size_t num) const
{
if (!(mFlags & HAS_TRIVIAL_COPY)) {
do_copy(dest, from, num);
} else {
memcpy(dest, from, num*itemSize());
}
}
void VectorImpl::_do_splat(void* dest, const void* item, size_t num) const {
do_splat(dest, item, num);
}
void VectorImpl::_do_move_forward(void* dest, const void* from, size_t num) const {
do_move_forward(dest, from, num);
}
void VectorImpl::_do_move_backward(void* dest, const void* from, size_t num) const {
do_move_backward(dest, from, num);
}
void VectorImpl::reservedVectorImpl1() { }
void VectorImpl::reservedVectorImpl2() { }
void VectorImpl::reservedVectorImpl3() { }
void VectorImpl::reservedVectorImpl4() { }
void VectorImpl::reservedVectorImpl5() { }
void VectorImpl::reservedVectorImpl6() { }
void VectorImpl::reservedVectorImpl7() { }
void VectorImpl::reservedVectorImpl8() { }
/*****************************************************************************/
SortedVectorImpl::SortedVectorImpl(size_t itemSize, uint32_t flags)
: VectorImpl(itemSize, flags)
{
}
SortedVectorImpl::SortedVectorImpl(const VectorImpl& rhs)
: VectorImpl(rhs)
{
}
SortedVectorImpl::~SortedVectorImpl()
{
}
SortedVectorImpl& SortedVectorImpl::operator = (const SortedVectorImpl& rhs)
{
return static_cast<SortedVectorImpl&>( VectorImpl::operator = (static_cast<const VectorImpl&>(rhs)) );
}
ssize_t SortedVectorImpl::indexOf(const void* item) const
{
return _indexOrderOf(item);
}
size_t SortedVectorImpl::orderOf(const void* item) const
{
size_t o;
_indexOrderOf(item, &o);
return o;
}
ssize_t SortedVectorImpl::_indexOrderOf(const void* item, size_t* order) const
{
// binary search
ssize_t err = NAME_NOT_FOUND;
ssize_t l = 0;
ssize_t h = size()-1;
ssize_t mid;
const void* a = arrayImpl();
const size_t s = itemSize();
while (l <= h) {
mid = l + (h - l)/2;
const void* const curr = reinterpret_cast<const char *>(a) + (mid*s);
const int c = do_compare(curr, item);
if (c == 0) {
err = l = mid;
break;
} else if (c < 0) {
l = mid + 1;
} else {
h = mid - 1;
}
}
if (order) *order = l;
return err;
}
ssize_t SortedVectorImpl::add(const void* item)
{
size_t order;
ssize_t index = _indexOrderOf(item, &order);
if (index < 0) {
index = VectorImpl::insertAt(item, order, 1);
} else {
index = VectorImpl::replaceAt(item, index);
}
return index;
}
ssize_t SortedVectorImpl::merge(const VectorImpl& vector)
{
// naive merge...
if (!vector.isEmpty()) {
const void* buffer = vector.arrayImpl();
const size_t is = itemSize();
size_t s = vector.size();
for (size_t i=0 ; i<s ; i++) {
ssize_t err = add( reinterpret_cast<const char*>(buffer) + i*is );
if (err<0) {
return err;
}
}
}
return NO_ERROR;
}
ssize_t SortedVectorImpl::merge(const SortedVectorImpl& vector)
{
// we've merging a sorted vector... nice!
ssize_t err = NO_ERROR;
if (!vector.isEmpty()) {
// first take care of the case where the vectors are sorted together
if (do_compare(vector.itemLocation(vector.size()-1), arrayImpl()) <= 0) {
err = VectorImpl::insertVectorAt(static_cast<const VectorImpl&>(vector), 0);
} else if (do_compare(vector.arrayImpl(), itemLocation(size()-1)) >= 0) {
err = VectorImpl::appendVector(static_cast<const VectorImpl&>(vector));
} else {
// this could be made a little better
err = merge(static_cast<const VectorImpl&>(vector));
}
}
return err;
}
ssize_t SortedVectorImpl::remove(const void* item)
{
ssize_t i = indexOf(item);
if (i>=0) {
VectorImpl::removeItemsAt(i, 1);
}
return i;
}
void SortedVectorImpl::reservedSortedVectorImpl1() { };
void SortedVectorImpl::reservedSortedVectorImpl2() { };
void SortedVectorImpl::reservedSortedVectorImpl3() { };
void SortedVectorImpl::reservedSortedVectorImpl4() { };
void SortedVectorImpl::reservedSortedVectorImpl5() { };
void SortedVectorImpl::reservedSortedVectorImpl6() { };
void SortedVectorImpl::reservedSortedVectorImpl7() { };
void SortedVectorImpl::reservedSortedVectorImpl8() { };
/*****************************************************************************/
}; // namespace android
Reference in a new issue View git blame Copy permalink