skia2/include/core/SkPtrRecorder.h
reed@google.com 8d90eeba09 add find()
git-svn-id: http://skia.googlecode.com/svn/trunk@1243 2bbb7eff-a529-9590-31e7-b0007b416f81
2011-05-04 18:03:00 +00:00

105 lines
3.1 KiB
C++

/*
* Copyright (C) 2008 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.
*/
#ifndef SkPtrSet_DEFINED
#define SkPtrSet_DEFINED
#include "SkRefCnt.h"
#include "SkTDArray.h"
/**
* Maintains a set of ptrs, assigning each a unique ID [1...N]. Duplicate ptrs
* return the same ID (since its a set). Subclasses can override inPtr()
* and decPtr(). incPtr() is called each time a unique ptr is added ot the
* set. decPtr() is called on each ptr when the set is destroyed or reset.
*/
class SkPtrSet : public SkRefCnt {
public:
/**
* Search for the specified ptr in the set. If it is found, return its
* 32bit ID [1..N], or if not found, return 0. Always returns 0 for NULL.
*/
uint32_t find(void*) const;
/**
* Add the specified ptr to the set, returning a unique 32bit ID for it
* [1...N]. Duplicate ptrs will return the same ID.
*
* If the ptr is NULL, it is not added, and 0 is returned.
*/
uint32_t add(void*);
/**
* Return the number of (non-null) ptrs in the set.
*/
int count() const { return fList.count(); }
/**
* Copy the ptrs in the set into the specified array (allocated by the
* caller). The ptrs are assgined to the array based on their corresponding
* ID. e.g. array[ptr.ID - 1] = ptr.
*
* incPtr() and decPtr() are not called during this operation.
*/
void copyToArray(void* array[]) const;
/**
* Call decPtr() on each ptr in the set, and the reset the size of the set
* to 0.
*/
void reset();
protected:
virtual void incPtr(void* ptr) {}
virtual void decPtr(void* ptr) {}
private:
struct Pair {
void* fPtr; // never NULL
uint32_t fIndex; // 1...N
};
// we store the ptrs in sorted-order (using Cmp) so that we can efficiently
// detect duplicates when add() is called. Hence we need to store the
// ptr and its ID/fIndex explicitly, since the ptr's position in the array
// is not related to its "index".
SkTDArray<Pair> fList;
static int Cmp(const Pair& a, const Pair& b);
typedef SkRefCnt INHERITED;
};
/**
* Templated wrapper for SkPtrSet, just meant to automate typecasting
* parameters to and from void* (which the base class expects).
*/
template <typename T> class SkTPtrSet : public SkPtrSet {
public:
uint32_t add(T ptr) {
return this->INHERITED::add((void*)ptr);
}
void copyToArray(T* array) const {
this->INHERITED::copyToArray((void**)array);
}
private:
typedef SkPtrSet INHERITED;
};
#endif