• Home
  • Line#
  • Scopes#
  • Navigate#
  • Raw
  • Download
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  */
23 class SkPtrSet : public SkRefCnt {
24 public:
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      */
count()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 
61 protected:
incPtr(void *)62     virtual void incPtr(void*) {}
decPtr(void *)63     virtual void decPtr(void*) {}
64 
65 private:
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  */
86 template <typename T> class SkTPtrSet : public SkPtrSet {
87 public:
find(T ptr)88     uint32_t find(T ptr) {
89         return this->INHERITED::find((void*)ptr);
90     }
add(T ptr)91     uint32_t add(T ptr) {
92         return this->INHERITED::add((void*)ptr);
93     }
94 
copyToArray(T * array)95     void copyToArray(T* array) const {
96         this->INHERITED::copyToArray((void**)array);
97     }
98 
99 private:
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  */
108 class SkRefCntSet : public SkTPtrSet<SkRefCnt*> {
109 public:
110     virtual ~SkRefCntSet();
111 
112 protected:
113     // overrides
114     virtual void incPtr(void*);
115     virtual void decPtr(void*);
116 };
117 
118 class 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  */
124 class SkNamedFactorySet : public SkRefCnt {
125 public:
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();
143 private:
144     int                    fNextAddedFactory;
145     SkFactorySet           fFactorySet;
146     SkTDArray<const char*> fNames;
147 
148     typedef SkRefCnt INHERITED;
149 };
150 
151 #endif
152