xref: /aosp_15_r20/external/skia/tools/UrlDataManager.h (revision c8dee2aa9b3f27cf6c858bd81872bdeb2c07ed17)
1 /*
2  * Copyright 2016 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 SkUrlDataManager_DEFINED
9 #define SkUrlDataManager_DEFINED
10 
11 #include "include/core/SkData.h"
12 #include "include/core/SkImage.h"
13 #include "include/core/SkString.h"
14 #include "src/core/SkChecksum.h"
15 #include "src/core/SkTDynamicHash.h"
16 
17 #include <unordered_map>
18 #include <vector>
19 
20 /*
21  * A simple class which allows clients to add opaque data types, and returns a url where this data
22  * will be hosted.  Its up to the owner of this class to actually serve the data.
23  */
24 bool operator==(const SkData& a, const SkData& b);
25 
26 class UrlDataManager {
27 public:
28     UrlDataManager(SkString rootUrl);
~UrlDataManager()29     ~UrlDataManager() { this->reset(); }
30 
31     /*
32      * Adds a data blob to the cache with a particular content type.  UrlDataManager will hash
33      * the blob data to ensure uniqueness
34      */
35     SkString addData(SkData*, const char* contentType);
36 
37     struct UrlData : public SkRefCnt {
38         SkString fUrl;
39         SkString fContentType;
40         sk_sp<SkData> fData;
41     };
42 
43     /*
44      * returns the UrlData object which should be hosted at 'url'
45      */
getDataFromUrl(const SkString & url)46     UrlData* getDataFromUrl(const SkString& url) {
47         return fUrlLookup.find(url);
48     }
49     void reset();
50 
51     // Methods used to identify images differently in wasm debugger for mskp animations.
52     // serving is uncessary, as a collection of images with identifiers is already present, we
53     // just want to use it when serializing commands.
54 
55     /*
56      * Construct an index from a list of images
57      * (expected to be the list that was loaded from the mskp file)
58      * Use only once.
59      */
60     void indexImages(const std::vector<sk_sp<SkImage>>&);
61 
62     /*
63      * Reports whether this UDM has an initialized image index (effevitely whether we're in wasm)
64      */
hasImageIndex()65     bool hasImageIndex() { return imageMap.size() > 0; }
66 
67     /*
68      * Return the file id (index of the image in the originally provided list) of an SkImage
69      */
70     int lookupImage(const SkImage*);
71 
72 private:
73     struct LookupTrait {
74         // We use the data as a hash, this is not really optimal but is fine until proven otherwise
GetKeyLookupTrait75         static const SkData& GetKey(const UrlData& data) {
76             return *data.fData;
77         }
78 
HashLookupTrait79         static uint32_t Hash(const SkData& key) {
80             return SkChecksum::Hash32(key.bytes(), key.size());
81         }
82     };
83 
84     struct ReverseLookupTrait {
GetKeyReverseLookupTrait85         static const SkString& GetKey(const UrlData& data) {
86             return data.fUrl;
87         }
88 
HashReverseLookupTrait89         static uint32_t Hash(const SkString& key) {
90             return SkChecksum::Hash32(key.c_str(), strlen(key.c_str()));
91         }
92     };
93 
94 
95     SkString fRootUrl;
96     SkTDynamicHash<UrlData, SkData, LookupTrait> fCache;
97     SkTDynamicHash<UrlData, SkString, ReverseLookupTrait> fUrlLookup;
98     uint32_t fDataId;
99     std::unordered_map<const SkImage*, int> imageMap;
100 };
101 
102 #endif
103