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 "SkChecksum.h"
12#include "SkData.h"
13#include "SkString.h"
14#include "SkTDynamicHash.h"
15
16/*
17 * A simple class which allows clients to add opaque data types, and returns a url where this data
18 * will be hosted.  Its up to the owner of this class to actually serve the data.
19 */
20bool operator==(const SkData& a, const SkData& b);
21
22class UrlDataManager {
23public:
24    UrlDataManager(SkString rootUrl);
25    ~UrlDataManager() { this->reset(); }
26
27    /*
28     * Adds a data blob to the cache with a particular content type.  UrlDataManager will hash
29     * the blob data to ensure uniqueness
30     */
31    SkString addData(SkData*, const char* contentType);
32
33    struct UrlData : public SkRefCnt {
34        SkString fUrl;
35        SkString fContentType;
36        SkAutoTUnref<SkData> fData;
37    };
38
39    /*
40     * returns the UrlData object which should be hosted at 'url'
41     */
42    UrlData* getDataFromUrl(SkString url) {
43        return fUrlLookup.find(url);
44    }
45    void reset();
46
47private:
48    struct LookupTrait {
49        // We use the data as a hash, this is not really optimal but is fine until proven otherwise
50        static const SkData& GetKey(const UrlData& data) {
51            return *data.fData.get();
52        }
53
54        static uint32_t Hash(const SkData& key) {
55            return SkChecksum::Murmur3(key.bytes(), key.size());
56        }
57    };
58
59    struct ReverseLookupTrait {
60        static const SkString& GetKey(const UrlData& data) {
61            return data.fUrl;
62        }
63
64        static uint32_t Hash(const SkString& key) {
65            return SkChecksum::Murmur3(key.c_str(), strlen(key.c_str()));
66        }
67    };
68
69
70    SkString fRootUrl;
71    SkTDynamicHash<UrlData, SkData, LookupTrait> fCache;
72    SkTDynamicHash<UrlData, SkString, ReverseLookupTrait> fUrlLookup;
73    uint32_t fDataId;
74};
75
76#endif
77