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1 /*
2  * Copyright 2014 Google Inc.
3  *
4  * Use of this source code is governed by a BSD-style license that can be
5  * found in the LICENSE file.
6  */
7 
8 #ifndef GrResourceKey_DEFINED
9 #define GrResourceKey_DEFINED
10 
11 #include "include/core/SkData.h"
12 #include "include/core/SkString.h"
13 #include "include/gpu/GrTypes.h"
14 #include "include/private/SkOnce.h"
15 #include "include/private/SkTemplates.h"
16 #include "include/private/SkTo.h"
17 
18 #include <new>
19 
20 uint32_t GrResourceKeyHash(const uint32_t* data, size_t size);
21 
22 /**
23  * Base class for all GrGpuResource cache keys. There are two types of cache keys. Refer to the
24  * comments for each key type below.
25  */
26 class GrResourceKey {
27 public:
hash()28     uint32_t hash() const {
29         this->validate();
30         return fKey[kHash_MetaDataIdx];
31     }
32 
size()33     size_t size() const {
34         this->validate();
35         SkASSERT(this->isValid());
36         return this->internalSize();
37     }
38 
39     /** Used to initialize a key. */
40     class Builder {
41     public:
~Builder()42         ~Builder() { this->finish(); }
43 
finish()44         void finish() {
45             if (nullptr == fKey) {
46                 return;
47             }
48             uint32_t* hash = &fKey->fKey[kHash_MetaDataIdx];
49             *hash = GrResourceKeyHash(hash + 1, fKey->internalSize() - sizeof(uint32_t));
50             fKey->validate();
51             fKey = nullptr;
52         }
53 
54         uint32_t& operator[](int dataIdx) {
55             SkASSERT(fKey);
56             SkDEBUGCODE(size_t dataCount = fKey->internalSize() / sizeof(uint32_t) - kMetaDataCnt;)
57                     SkASSERT(SkToU32(dataIdx) < dataCount);
58             return fKey->fKey[(int)kMetaDataCnt + dataIdx];
59         }
60 
61     protected:
Builder(GrResourceKey * key,uint32_t domain,int data32Count)62         Builder(GrResourceKey* key, uint32_t domain, int data32Count) : fKey(key) {
63             size_t count = SkToSizeT(data32Count);
64             SkASSERT(domain != kInvalidDomain);
65             key->fKey.reset(kMetaDataCnt + count);
66             size_t size = (count + kMetaDataCnt) * sizeof(uint32_t);
67             SkASSERT(SkToU16(size) == size);
68             SkASSERT(SkToU16(domain) == domain);
69             key->fKey[kDomainAndSize_MetaDataIdx] = domain | (size << 16);
70         }
71 
72     private:
73         GrResourceKey* fKey;
74     };
75 
76 protected:
77     static const uint32_t kInvalidDomain = 0;
78 
GrResourceKey()79     GrResourceKey() { this->reset(); }
80 
81     /** Reset to an invalid key. */
reset()82     void reset() {
83         fKey.reset(kMetaDataCnt);
84         fKey[kHash_MetaDataIdx] = 0;
85         fKey[kDomainAndSize_MetaDataIdx] = kInvalidDomain;
86     }
87 
88     bool operator==(const GrResourceKey& that) const {
89         // Both keys should be sized to at least contain the meta data. The metadata contains each
90         // key's length. So the second memcmp should only run if the keys have the same length.
91         return 0 == memcmp(fKey.get(), that.fKey.get(), kMetaDataCnt*sizeof(uint32_t)) &&
92                0 == memcmp(&fKey[kMetaDataCnt], &that.fKey[kMetaDataCnt], this->dataSize());
93     }
94 
95     GrResourceKey& operator=(const GrResourceKey& that) {
96         if (this != &that) {
97             if (!that.isValid()) {
98                 this->reset();
99             } else {
100                 size_t bytes = that.size();
101                 SkASSERT(SkIsAlign4(bytes));
102                 fKey.reset(bytes / sizeof(uint32_t));
103                 memcpy(fKey.get(), that.fKey.get(), bytes);
104                 this->validate();
105             }
106         }
107         return *this;
108     }
109 
isValid()110     bool isValid() const { return kInvalidDomain != this->domain(); }
111 
domain()112     uint32_t domain() const { return fKey[kDomainAndSize_MetaDataIdx] & 0xffff; }
113 
114     /** size of the key data, excluding meta-data (hash, domain, etc).  */
dataSize()115     size_t dataSize() const { return this->size() - 4 * kMetaDataCnt; }
116 
117     /** ptr to the key data, excluding meta-data (hash, domain, etc).  */
data()118     const uint32_t* data() const {
119         this->validate();
120         return &fKey[kMetaDataCnt];
121     }
122 
123 #ifdef SK_DEBUG
dump()124     void dump() const {
125         if (!this->isValid()) {
126             SkDebugf("Invalid Key\n");
127         } else {
128             SkDebugf("hash: %d ", this->hash());
129             SkDebugf("domain: %d ", this->domain());
130             SkDebugf("size: %dB ", this->internalSize());
131             size_t dataCount = this->internalSize() / sizeof(uint32_t) - kMetaDataCnt;
132             for (size_t i = 0; i < dataCount; ++i) {
133                 SkDebugf("%d ", fKey[SkTo<int>(kMetaDataCnt+i)]);
134             }
135             SkDebugf("\n");
136         }
137     }
138 #endif
139 
140 private:
141     enum MetaDataIdx {
142         kHash_MetaDataIdx,
143         // The key domain and size are packed into a single uint32_t.
144         kDomainAndSize_MetaDataIdx,
145 
146         kLastMetaDataIdx = kDomainAndSize_MetaDataIdx
147     };
148     static const uint32_t kMetaDataCnt = kLastMetaDataIdx + 1;
149 
internalSize()150     size_t internalSize() const { return fKey[kDomainAndSize_MetaDataIdx] >> 16; }
151 
validate()152     void validate() const {
153         SkASSERT(this->isValid());
154         SkASSERT(fKey[kHash_MetaDataIdx] ==
155                  GrResourceKeyHash(&fKey[kHash_MetaDataIdx] + 1,
156                                    this->internalSize() - sizeof(uint32_t)));
157         SkASSERT(SkIsAlign4(this->internalSize()));
158     }
159 
160     friend class TestResource;  // For unit test to access kMetaDataCnt.
161 
162     // bmp textures require 5 uint32_t values.
163     SkAutoSTMalloc<kMetaDataCnt + 5, uint32_t> fKey;
164 };
165 
166 /**
167  * A key used for scratch resources. There are three important rules about scratch keys:
168  *        * Multiple resources can share the same scratch key. Therefore resources assigned the same
169  *          scratch key should be interchangeable with respect to the code that uses them.
170  *        * A resource can have at most one scratch key and it is set at resource creation by the
171  *          resource itself.
172  *        * When a scratch resource is ref'ed it will not be returned from the
173  *          cache for a subsequent cache request until all refs are released. This facilitates using
174  *          a scratch key for multiple render-to-texture scenarios. An example is a separable blur:
175  *
176  *  GrTexture* texture[2];
177  *  texture[0] = get_scratch_texture(scratchKey);
178  *  texture[1] = get_scratch_texture(scratchKey); // texture[0] is already owned so we will get a
179  *                                                // different one for texture[1]
180  *  draw_mask(texture[0], path);        // draws path mask to texture[0]
181  *  blur_x(texture[0], texture[1]);     // blurs texture[0] in y and stores result in texture[1]
182  *  blur_y(texture[1], texture[0]);     // blurs texture[1] in y and stores result in texture[0]
183  *  texture[1]->unref();  // texture 1 can now be recycled for the next request with scratchKey
184  *  consume_blur(texture[0]);
185  *  texture[0]->unref();  // texture 0 can now be recycled for the next request with scratchKey
186  */
187 class GrScratchKey : public GrResourceKey {
188 private:
189     using INHERITED = GrResourceKey;
190 
191 public:
192     /** Uniquely identifies the type of resource that is cached as scratch. */
193     typedef uint32_t ResourceType;
194 
195     /** Generate a unique ResourceType. */
196     static ResourceType GenerateResourceType();
197 
198     /** Creates an invalid scratch key. It must be initialized using a Builder object before use. */
GrScratchKey()199     GrScratchKey() {}
200 
GrScratchKey(const GrScratchKey & that)201     GrScratchKey(const GrScratchKey& that) { *this = that; }
202 
203     /** reset() returns the key to the invalid state. */
204     using INHERITED::reset;
205 
206     using INHERITED::isValid;
207 
resourceType()208     ResourceType resourceType() const { return this->domain(); }
209 
210     GrScratchKey& operator=(const GrScratchKey& that) {
211         this->INHERITED::operator=(that);
212         return *this;
213     }
214 
215     bool operator==(const GrScratchKey& that) const { return this->INHERITED::operator==(that); }
216     bool operator!=(const GrScratchKey& that) const { return !(*this == that); }
217 
218     class Builder : public INHERITED::Builder {
219     public:
Builder(GrScratchKey * key,ResourceType type,int data32Count)220         Builder(GrScratchKey* key, ResourceType type, int data32Count)
221                 : INHERITED::Builder(key, type, data32Count) {}
222     };
223 };
224 
225 /**
226  * A key that allows for exclusive use of a resource for a use case (AKA "domain"). There are three
227  * rules governing the use of unique keys:
228  *        * Only one resource can have a given unique key at a time. Hence, "unique".
229  *        * A resource can have at most one unique key at a time.
230  *        * Unlike scratch keys, multiple requests for a unique key will return the same
231  *          resource even if the resource already has refs.
232  * This key type allows a code path to create cached resources for which it is the exclusive user.
233  * The code path creates a domain which it sets on its keys. This guarantees that there are no
234  * cross-domain collisions.
235  *
236  * Unique keys preempt scratch keys. While a resource has a unique key it is inaccessible via its
237  * scratch key. It can become scratch again if the unique key is removed.
238  */
239 class GrUniqueKey : public GrResourceKey {
240 private:
241     using INHERITED = GrResourceKey;
242 
243 public:
244     typedef uint32_t Domain;
245     /** Generate a Domain for unique keys. */
246     static Domain GenerateDomain();
247 
248     /** Creates an invalid unique key. It must be initialized using a Builder object before use. */
GrUniqueKey()249     GrUniqueKey() : fTag(nullptr) {}
250 
GrUniqueKey(const GrUniqueKey & that)251     GrUniqueKey(const GrUniqueKey& that) { *this = that; }
252 
253     /** reset() returns the key to the invalid state. */
254     using INHERITED::reset;
255 
256     using INHERITED::isValid;
257 
258     GrUniqueKey& operator=(const GrUniqueKey& that) {
259         this->INHERITED::operator=(that);
260         this->setCustomData(sk_ref_sp(that.getCustomData()));
261         fTag = that.fTag;
262         return *this;
263     }
264 
265     bool operator==(const GrUniqueKey& that) const { return this->INHERITED::operator==(that); }
266     bool operator!=(const GrUniqueKey& that) const { return !(*this == that); }
267 
setCustomData(sk_sp<SkData> data)268     void setCustomData(sk_sp<SkData> data) { fData = std::move(data); }
getCustomData()269     SkData* getCustomData() const { return fData.get(); }
refCustomData()270     sk_sp<SkData> refCustomData() const { return fData; }
271 
tag()272     const char* tag() const { return fTag; }
273 
274 #ifdef SK_DEBUG
dump(const char * label)275     void dump(const char* label) const {
276         SkDebugf("%s tag: %s\n", label, fTag ? fTag : "None");
277         this->INHERITED::dump();
278     }
279 #endif
280 
281     class Builder : public INHERITED::Builder {
282     public:
283         Builder(GrUniqueKey* key, Domain type, int data32Count, const char* tag = nullptr)
Builder(key,type,data32Count)284                 : INHERITED::Builder(key, type, data32Count) {
285             key->fTag = tag;
286         }
287 
288         /** Used to build a key that wraps another key and adds additional data. */
289         Builder(GrUniqueKey* key, const GrUniqueKey& innerKey, Domain domain, int extraData32Cnt,
290                 const char* tag = nullptr)
291                 : INHERITED::Builder(key, domain, Data32CntForInnerKey(innerKey) + extraData32Cnt) {
292             SkASSERT(&innerKey != key);
293             // add the inner key to the end of the key so that op[] can be indexed normally.
294             uint32_t* innerKeyData = &this->operator[](extraData32Cnt);
295             const uint32_t* srcData = innerKey.data();
296             (*innerKeyData++) = innerKey.domain();
297             memcpy(innerKeyData, srcData, innerKey.dataSize());
298             key->fTag = tag;
299         }
300 
301     private:
Data32CntForInnerKey(const GrUniqueKey & innerKey)302         static int Data32CntForInnerKey(const GrUniqueKey& innerKey) {
303             // key data + domain
304             return SkToInt((innerKey.dataSize() >> 2) + 1);
305         }
306     };
307 
308 private:
309     sk_sp<SkData> fData;
310     const char* fTag;
311 };
312 
313 /**
314  * It is common to need a frequently reused GrUniqueKey where the only requirement is that the key
315  * is unique. These macros create such a key in a thread safe manner so the key can be truly global
316  * and only constructed once.
317  */
318 
319 /** Place outside of function/class definitions. */
320 #define GR_DECLARE_STATIC_UNIQUE_KEY(name) static SkOnce name##_once
321 
322 /** Place inside function where the key is used. */
323 #define GR_DEFINE_STATIC_UNIQUE_KEY(name)                         \
324     static SkAlignedSTStorage<1, GrUniqueKey> name##_storage;     \
325     name##_once(gr_init_static_unique_key_once, &name##_storage); \
326     static const GrUniqueKey& name = *reinterpret_cast<GrUniqueKey*>(name##_storage.get())
327 
gr_init_static_unique_key_once(SkAlignedSTStorage<1,GrUniqueKey> * keyStorage)328 static inline void gr_init_static_unique_key_once(SkAlignedSTStorage<1, GrUniqueKey>* keyStorage) {
329     GrUniqueKey* key = new (keyStorage->get()) GrUniqueKey;
330     GrUniqueKey::Builder builder(key, GrUniqueKey::GenerateDomain(), 0);
331 }
332 
333 // The cache listens for these messages to purge junk resources proactively.
334 class GrUniqueKeyInvalidatedMessage {
335 public:
336     GrUniqueKeyInvalidatedMessage() = default;
337     GrUniqueKeyInvalidatedMessage(const GrUniqueKey& key, uint32_t contextUniqueID,
338                                   bool inThreadSafeCache = false)
fKey(key)339             : fKey(key), fContextID(contextUniqueID), fInThreadSafeCache(inThreadSafeCache) {
340         SkASSERT(SK_InvalidUniqueID != contextUniqueID);
341     }
342 
343     GrUniqueKeyInvalidatedMessage(const GrUniqueKeyInvalidatedMessage&) = default;
344 
345     GrUniqueKeyInvalidatedMessage& operator=(const GrUniqueKeyInvalidatedMessage&) = default;
346 
key()347     const GrUniqueKey& key() const { return fKey; }
contextID()348     uint32_t contextID() const { return fContextID; }
inThreadSafeCache()349     bool inThreadSafeCache() const { return fInThreadSafeCache; }
350 
351 private:
352     GrUniqueKey fKey;
353     uint32_t fContextID = SK_InvalidUniqueID;
354     bool fInThreadSafeCache = false;
355 };
356 
SkShouldPostMessageToBus(const GrUniqueKeyInvalidatedMessage & msg,uint32_t msgBusUniqueID)357 static inline bool SkShouldPostMessageToBus(const GrUniqueKeyInvalidatedMessage& msg,
358                                             uint32_t msgBusUniqueID) {
359     return msg.contextID() == msgBusUniqueID;
360 }
361 
362 #endif
363