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1 /*
2  * Copyright (C) 2006 The Android Open Source Project
3  *
4  * Licensed under the Apache License, Version 2.0 (the "License");
5  * you may not use this file except in compliance with the License.
6  * You may obtain a copy of the License at
7  *
8  *      http://www.apache.org/licenses/LICENSE-2.0
9  *
10  * Unless required by applicable law or agreed to in writing, software
11  * distributed under the License is distributed on an "AS IS" BASIS,
12  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
13  * See the License for the specific language governing permissions and
14  * limitations under the License.
15  */
16 
17 #ifndef SkMetaData_DEFINED
18 #define SkMetaData_DEFINED
19 
20 #include "SkScalar.h"
21 
22 class SkRefCnt;
23 
24 class SK_API SkMetaData {
25 public:
26     /**
27      *  Used to manage the life-cycle of a ptr in the metadata. This is option
28      *  in setPtr, and is only invoked when either copying one metadata to
29      *  another, or when the metadata is destroyed.
30      *
31      *  setPtr(name, ptr, proc) {
32      *      fPtr = proc(ptr, true);
33      *  }
34      *
35      *  copy: A = B {
36      *      A.fPtr = B.fProc(B.fPtr, true);
37      *  }
38      *
39      *  ~SkMetaData {
40      *      fProc(fPtr, false);
41      *  }
42      */
43     typedef void* (*PtrProc)(void* ptr, bool doRef);
44 
45     /**
46      *  Implements PtrProc for SkRefCnt pointers
47      */
48     static void* RefCntProc(void* ptr, bool doRef);
49 
50     SkMetaData();
51     SkMetaData(const SkMetaData& src);
52     ~SkMetaData();
53 
54     SkMetaData& operator=(const SkMetaData& src);
55 
56     void reset();
57 
58     bool findS32(const char name[], int32_t* value = NULL) const;
59     bool findScalar(const char name[], SkScalar* value = NULL) const;
60     const SkScalar* findScalars(const char name[], int* count,
61                                 SkScalar values[] = NULL) const;
62     const char* findString(const char name[]) const;
63     bool findPtr(const char name[], void** value = NULL, PtrProc* = NULL) const;
64     bool findBool(const char name[], bool* value = NULL) const;
65     const void* findData(const char name[], size_t* byteCount = NULL) const;
66 
hasS32(const char name[],int32_t value)67     bool hasS32(const char name[], int32_t value) const {
68         int32_t v;
69         return this->findS32(name, &v) && v == value;
70     }
hasScalar(const char name[],SkScalar value)71     bool hasScalar(const char name[], SkScalar value) const {
72         SkScalar v;
73         return this->findScalar(name, &v) && v == value;
74     }
hasString(const char name[],const char value[])75     bool hasString(const char name[], const char value[]) const {
76         const char* v = this->findString(name);
77         return  (v == NULL && value == NULL) ||
78                 (v != NULL && value != NULL && !strcmp(v, value));
79     }
hasPtr(const char name[],void * value)80     bool hasPtr(const char name[], void* value) const {
81         void* v;
82         return this->findPtr(name, &v) && v == value;
83     }
hasBool(const char name[],bool value)84     bool hasBool(const char name[], bool value) const {
85         bool    v;
86         return this->findBool(name, &v) && v == value;
87     }
hasData(const char name[],const void * data,size_t byteCount)88     bool hasData(const char name[], const void* data, size_t byteCount) const {
89         size_t len;
90         const void* ptr = this->findData(name, &len);
91         return NULL != ptr && len == byteCount && !memcmp(ptr, data, len);
92     }
93 
94     void setS32(const char name[], int32_t value);
95     void setScalar(const char name[], SkScalar value);
96     SkScalar* setScalars(const char name[], int count, const SkScalar values[] = NULL);
97     void setString(const char name[], const char value[]);
98     void setPtr(const char name[], void* value, PtrProc proc = NULL);
99     void setBool(const char name[], bool value);
100     // the data is copied from the input pointer.
101     void setData(const char name[], const void* data, size_t byteCount);
102 
103     bool removeS32(const char name[]);
104     bool removeScalar(const char name[]);
105     bool removeString(const char name[]);
106     bool removePtr(const char name[]);
107     bool removeBool(const char name[]);
108     bool removeData(const char name[]);
109 
110     // helpers for SkRefCnt
111     bool findRefCnt(const char name[], SkRefCnt** ptr = NULL) {
112         return this->findPtr(name, reinterpret_cast<void**>(ptr));
113     }
hasRefCnt(const char name[],SkRefCnt * ptr)114     bool hasRefCnt(const char name[], SkRefCnt* ptr) {
115         return this->hasPtr(name, ptr);
116     }
setRefCnt(const char name[],SkRefCnt * ptr)117     void setRefCnt(const char name[], SkRefCnt* ptr) {
118         this->setPtr(name, ptr, RefCntProc);
119     }
removeRefCnt(const char name[])120     bool removeRefCnt(const char name[]) {
121         return this->removePtr(name);
122     }
123 
124     enum Type {
125         kS32_Type,
126         kScalar_Type,
127         kString_Type,
128         kPtr_Type,
129         kBool_Type,
130         kData_Type,
131 
132         kTypeCount
133     };
134 
135     struct Rec;
136     class Iter;
137     friend class Iter;
138 
139     class Iter {
140     public:
Iter()141         Iter() : fRec(NULL) {}
142         Iter(const SkMetaData&);
143 
144         /** Reset the iterator, so that calling next() will return the first
145             data element. This is done implicitly in the constructor.
146         */
147         void reset(const SkMetaData&);
148 
149         /** Each time next is called, it returns the name of the next data element,
150             or null when there are no more elements. If non-null is returned, then the
151             element's type is returned (if not null), and the number of data values
152             is returned in count (if not null).
153         */
154         const char* next(Type*, int* count);
155 
156     private:
157         Rec* fRec;
158     };
159 
160 public:
161     struct Rec {
162         Rec*        fNext;
163         uint16_t    fDataCount; // number of elements
164         uint8_t     fDataLen;   // sizeof a single element
165         uint8_t     fType;
166 
dataRec167         const void* data() const { return (this + 1); }
dataRec168         void*       data() { return (this + 1); }
nameRec169         const char* name() const { return (const char*)this->data() + fDataLen * fDataCount; }
nameRec170         char*       name() { return (char*)this->data() + fDataLen * fDataCount; }
171 
172         static Rec* Alloc(size_t);
173         static void Free(Rec*);
174     };
175     Rec*    fRec;
176 
177     const Rec* find(const char name[], Type) const;
178     void* set(const char name[], const void* data, size_t len, Type, int count);
179     bool remove(const char name[], Type);
180 };
181 
182 #endif
183 
184