1
2/*
3 * Copyright 2008 The Android Open Source Project
4 *
5 * Use of this source code is governed by a BSD-style license that can be
6 * found in the LICENSE file.
7 */
8
9
10#ifndef SkPtrSet_DEFINED
11#define SkPtrSet_DEFINED
12
13#include "SkRefCnt.h"
14#include "SkFlattenable.h"
15#include "SkTDArray.h"
16
17/**
18 *  Maintains a set of ptrs, assigning each a unique ID [1...N]. Duplicate ptrs
19 *  return the same ID (since its a set). Subclasses can override inPtr()
20 *  and decPtr(). incPtr() is called each time a unique ptr is added ot the
21 *  set. decPtr() is called on each ptr when the set is destroyed or reset.
22 */
23class SkPtrSet : public SkRefCnt {
24public:
25    SK_DECLARE_INST_COUNT(SkPtrSet)
26
27    /**
28     *  Search for the specified ptr in the set. If it is found, return its
29     *  32bit ID [1..N], or if not found, return 0. Always returns 0 for NULL.
30     */
31    uint32_t find(void*) const;
32
33    /**
34     *  Add the specified ptr to the set, returning a unique 32bit ID for it
35     *  [1...N]. Duplicate ptrs will return the same ID.
36     *
37     *  If the ptr is NULL, it is not added, and 0 is returned.
38     */
39    uint32_t add(void*);
40
41    /**
42     *  Return the number of (non-null) ptrs in the set.
43     */
44    int count() const { return fList.count(); }
45
46    /**
47     *  Copy the ptrs in the set into the specified array (allocated by the
48     *  caller). The ptrs are assgined to the array based on their corresponding
49     *  ID. e.g. array[ptr.ID - 1] = ptr.
50     *
51     *  incPtr() and decPtr() are not called during this operation.
52     */
53    void copyToArray(void* array[]) const;
54
55    /**
56     *  Call decPtr() on each ptr in the set, and the reset the size of the set
57     *  to 0.
58     */
59    void reset();
60
61protected:
62    virtual void incPtr(void*) {}
63    virtual void decPtr(void*) {}
64
65private:
66    struct Pair {
67        void*       fPtr;   // never NULL
68        uint32_t    fIndex; // 1...N
69    };
70
71    // we store the ptrs in sorted-order (using Cmp) so that we can efficiently
72    // detect duplicates when add() is called. Hence we need to store the
73    // ptr and its ID/fIndex explicitly, since the ptr's position in the array
74    // is not related to its "index".
75    SkTDArray<Pair>  fList;
76
77    static bool Less(const Pair& a, const Pair& b);
78
79    typedef SkRefCnt INHERITED;
80};
81
82/**
83 *  Templated wrapper for SkPtrSet, just meant to automate typecasting
84 *  parameters to and from void* (which the base class expects).
85 */
86template <typename T> class SkTPtrSet : public SkPtrSet {
87public:
88    uint32_t find(T ptr) {
89        return this->INHERITED::find((void*)ptr);
90    }
91    uint32_t add(T ptr) {
92        return this->INHERITED::add((void*)ptr);
93    }
94
95    void copyToArray(T* array) const {
96        this->INHERITED::copyToArray((void**)array);
97    }
98
99private:
100    typedef SkPtrSet INHERITED;
101};
102
103/**
104 *  Subclass of SkTPtrSet specialed to call ref() and unref() when the
105 *  base class's incPtr() and decPtr() are called. This makes it a valid owner
106 *  of each ptr, which is released when the set is reset or destroyed.
107 */
108class SkRefCntSet : public SkTPtrSet<SkRefCnt*> {
109public:
110    virtual ~SkRefCntSet();
111
112protected:
113    // overrides
114    virtual void incPtr(void*);
115    virtual void decPtr(void*);
116};
117
118class SkFactorySet : public SkTPtrSet<SkFlattenable::Factory> {};
119
120/**
121 * Similar to SkFactorySet, but only allows Factorys that have registered names.
122 * Also has a function to return the next added Factory's name.
123 */
124class SkNamedFactorySet : public SkRefCnt {
125public:
126    SK_DECLARE_INST_COUNT(SkNamedFactorySet)
127
128    SkNamedFactorySet();
129
130    /**
131     * Find the specified Factory in the set. If it is not already in the set,
132     * and has registered its name, add it to the set, and return its index.
133     * If the Factory has no registered name, return 0.
134     */
135    uint32_t find(SkFlattenable::Factory);
136
137    /**
138     * If new Factorys have been added to the set, return the name of the first
139     * Factory added after the Factory name returned by the last call to this
140     * function.
141     */
142    const char* getNextAddedFactoryName();
143private:
144    int                    fNextAddedFactory;
145    SkFactorySet           fFactorySet;
146    SkTDArray<const char*> fNames;
147
148    typedef SkRefCnt INHERITED;
149};
150
151#endif
152