skia2/include/core/SkPtrRecorder.h
2012-06-21 20:25:03 +00:00

103 lines
2.8 KiB
C++

/*
* Copyright 2008 The Android Open Source Project
*
* Use of this source code is governed by a BSD-style license that can be
* found in the LICENSE file.
*/
#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:
SK_DECLARE_INST_COUNT(SkPtrSet)
/**
* 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 find(T ptr) {
return this->INHERITED::find((void*)ptr);
}
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