platform_system_core/libutils/VectorImpl.cpp

682 lines
20 KiB
C++

/*
* 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 <cutils/log.h>
#include <safe_iop.h>
#include <utils/Errors.h>
#include <utils/VectorImpl.h>
#include "SharedBuffer.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::bufferFromData(mStorage)->acquire();
}
}
VectorImpl::~VectorImpl()
{
ALOGW_IF(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_ALWAYS_FATAL_IF(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::bufferFromData(mStorage)->acquire();
} else {
mStorage = 0;
mCount = 0;
}
}
return *this;
}
void* VectorImpl::editArrayImpl()
{
if (mStorage) {
const SharedBuffer* sb = SharedBuffer::bufferFromData(mStorage);
SharedBuffer* editable = sb->attemptEdit();
if (editable == 0) {
// If we're here, we're not the only owner of the buffer.
// We must make a copy of it.
editable = SharedBuffer::alloc(sb->size());
// Fail instead of returning a pointer to storage that's not
// editable. Otherwise we'd be editing the contents of a buffer
// for which we're not the only owner, which is undefined behaviour.
LOG_ALWAYS_FATAL_IF(editable == NULL);
_do_copy(editable->data(), mStorage, mCount);
release_storage();
mStorage = editable->data();
}
}
return mStorage;
}
size_t VectorImpl::capacity() const
{
if (mStorage) {
return SharedBuffer::bufferFromData(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 = NULL;
if (j >= 0) {
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)
{
ALOG_ASSERT(index<size(),
"[%p] replace: index=%d, size=%d", this, (int)index, (int)size());
if (index >= size()) {
return BAD_INDEX;
}
void* item = editItemLocation(index);
if (item != prototype) {
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)
{
ALOG_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)
{
ALOG_ASSERT(index<capacity(),
"[%p] editItemLocation: index=%d, capacity=%d, count=%d",
this, (int)index, (int)capacity(), (int)mCount);
if (index < capacity()) {
void* buffer = editArrayImpl();
if (buffer) {
return reinterpret_cast<char*>(buffer) + index*mItemSize;
}
}
return 0;
}
const void* VectorImpl::itemLocation(size_t index) const
{
ALOG_ASSERT(index<capacity(),
"[%p] itemLocation: index=%d, capacity=%d, count=%d",
this, (int)index, (int)capacity(), (int)mCount);
if (index < capacity()) {
const void* buffer = arrayImpl();
if (buffer) {
return reinterpret_cast<const char*>(buffer) + index*mItemSize;
}
}
return 0;
}
ssize_t VectorImpl::setCapacity(size_t new_capacity)
{
// The capacity must always be greater than or equal to the size
// of this vector.
if (new_capacity <= size()) {
return capacity();
}
size_t new_allocation_size = 0;
LOG_ALWAYS_FATAL_IF(!safe_mul(&new_allocation_size, new_capacity, mItemSize));
SharedBuffer* sb = SharedBuffer::alloc(new_allocation_size);
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;
}
ssize_t VectorImpl::resize(size_t size) {
ssize_t result = NO_ERROR;
if (size > mCount) {
result = insertAt(mCount, size - mCount);
} else if (size < mCount) {
result = removeItemsAt(size, mCount - size);
}
return result < 0 ? result : size;
}
void VectorImpl::release_storage()
{
if (mStorage) {
const SharedBuffer* sb = SharedBuffer::bufferFromData(mStorage);
if (sb->release(SharedBuffer::eKeepStorage) == 1) {
_do_destroy(mStorage, mCount);
SharedBuffer::dealloc(sb);
}
}
}
void* VectorImpl::_grow(size_t where, size_t amount)
{
// ALOGV("_grow(this=%p, where=%d, amount=%d) count=%d, capacity=%d",
// this, (int)where, (int)amount, (int)mCount, (int)capacity());
ALOG_ASSERT(where <= mCount,
"[%p] _grow: where=%d, amount=%d, count=%d",
this, (int)where, (int)amount, (int)mCount); // caller already checked
size_t new_size;
LOG_ALWAYS_FATAL_IF(!safe_add(&new_size, mCount, amount), "new_size overflow");
if (capacity() < new_size) {
// NOTE: This implementation used to resize vectors as per ((3*x + 1) / 2)
// (sigh..). Also note, the " + 1" was necessary to handle the special case
// where x == 1, where the resized_capacity will be equal to the old
// capacity without the +1. The old calculation wouldn't work properly
// if x was zero.
//
// This approximates the old calculation, using (x + (x/2) + 1) instead.
size_t new_capacity = 0;
LOG_ALWAYS_FATAL_IF(!safe_add(&new_capacity, new_size, (new_size / 2)),
"new_capacity overflow");
LOG_ALWAYS_FATAL_IF(!safe_add(&new_capacity, new_capacity, static_cast<size_t>(1u)),
"new_capacity overflow");
new_capacity = max(kMinVectorCapacity, new_capacity);
size_t new_alloc_size = 0;
LOG_ALWAYS_FATAL_IF(!safe_mul(&new_alloc_size, new_capacity, mItemSize),
"new_alloc_size overflow");
// ALOGV("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::bufferFromData(mStorage);
SharedBuffer* sb = cur_sb->editResize(new_alloc_size);
if (sb) {
mStorage = sb->data();
} else {
return NULL;
}
} else {
SharedBuffer* sb = SharedBuffer::alloc(new_alloc_size);
if (sb) {
void* array = sb->data();
if (where != 0) {
_do_copy(array, mStorage, where);
}
if (where != mCount) {
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 {
return NULL;
}
}
} else {
void* array = editArrayImpl();
if (where != mCount) {
const void* from = reinterpret_cast<const uint8_t *>(array) + where*mItemSize;
void* to = reinterpret_cast<uint8_t *>(array) + (where+amount)*mItemSize;
_do_move_forward(to, from, mCount - where);
}
}
mCount = new_size;
void* free_space = const_cast<void*>(itemLocation(where));
return free_space;
}
void VectorImpl::_shrink(size_t where, size_t amount)
{
if (!mStorage)
return;
// ALOGV("_shrink(this=%p, where=%d, amount=%d) count=%d, capacity=%d",
// this, (int)where, (int)amount, (int)mCount, (int)capacity());
ALOG_ASSERT(where + amount <= mCount,
"[%p] _shrink: where=%d, amount=%d, count=%d",
this, (int)where, (int)amount, (int)mCount); // caller already checked
size_t new_size;
LOG_ALWAYS_FATAL_IF(!safe_sub(&new_size, mCount, amount));
if (new_size < (capacity() / 2)) {
// NOTE: (new_size * 2) is safe because capacity didn't overflow and
// new_size < (capacity / 2)).
const size_t new_capacity = max(kMinVectorCapacity, new_size * 2);
// NOTE: (new_capacity * mItemSize), (where * mItemSize) and
// ((where + amount) * mItemSize) beyond this point are safe because
// we are always reducing the capacity of the underlying SharedBuffer.
// In other words, (old_capacity * mItemSize) did not overflow, and
// where < (where + amount) < new_capacity < old_capacity.
if ((where == new_size) &&
(mFlags & HAS_TRIVIAL_COPY) &&
(mFlags & HAS_TRIVIAL_DTOR))
{
const SharedBuffer* cur_sb = SharedBuffer::bufferFromData(mStorage);
SharedBuffer* sb = cur_sb->editResize(new_capacity * mItemSize);
if (sb) {
mStorage = sb->data();
} else {
return;
}
} else {
SharedBuffer* sb = SharedBuffer::alloc(new_capacity * mItemSize);
if (sb) {
void* array = sb->data();
if (where != 0) {
_do_copy(array, mStorage, where);
}
if (where != new_size) {
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, new_size - where);
}
release_storage();
mStorage = const_cast<void*>(array);
} else{
return;
}
}
} else {
void* array = editArrayImpl();
void* to = reinterpret_cast<uint8_t *>(array) + where*mItemSize;
_do_destroy(to, amount);
if (where != new_size) {
const void* from = reinterpret_cast<uint8_t *>(array) + (where+amount)*mItemSize;
_do_move_backward(to, from, new_size - where);
}
}
mCount = new_size;
}
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);
}
/*****************************************************************************/
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
{
if (order) *order = 0;
if (isEmpty()) {
return NAME_NOT_FOUND;
}
// 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;
}
/*****************************************************************************/
}; // namespace android