skia2/tools/UrlDataManager.h

77 lines
2.0 KiB
C++

/*
* Copyright 2016 Google Inc.
*
* Use of this source code is governed by a BSD-style license that can be
* found in the LICENSE file.
*/
#ifndef SkUrlDataManager_DEFINED
#define SkUrlDataManager_DEFINED
#include "SkChecksum.h"
#include "SkData.h"
#include "SkString.h"
#include "SkTDynamicHash.h"
/*
* A simple class which allows clients to add opaque data types, and returns a url where this data
* will be hosted. Its up to the owner of this class to actually serve the data.
*/
bool operator==(const SkData& a, const SkData& b);
class UrlDataManager {
public:
UrlDataManager(SkString rootUrl);
~UrlDataManager() { this->reset(); }
/*
* Adds a data blob to the cache with a particular content type. UrlDataManager will hash
* the blob data to ensure uniqueness
*/
SkString addData(SkData*, const char* contentType);
struct UrlData : public SkRefCnt {
SkString fUrl;
SkString fContentType;
SkAutoTUnref<SkData> fData;
};
/*
* returns the UrlData object which should be hosted at 'url'
*/
UrlData* getDataFromUrl(SkString url) {
return fUrlLookup.find(url);
}
void reset();
private:
struct LookupTrait {
// We use the data as a hash, this is not really optimal but is fine until proven otherwise
static const SkData& GetKey(const UrlData& data) {
return *data.fData.get();
}
static uint32_t Hash(const SkData& key) {
return SkChecksum::Murmur3(key.bytes(), key.size());
}
};
struct ReverseLookupTrait {
static const SkString& GetKey(const UrlData& data) {
return data.fUrl;
}
static uint32_t Hash(const SkString& key) {
return SkChecksum::Murmur3(key.c_str(), strlen(key.c_str()));
}
};
SkString fRootUrl;
SkTDynamicHash<UrlData, SkData, LookupTrait> fCache;
SkTDynamicHash<UrlData, SkString, ReverseLookupTrait> fUrlLookup;
uint32_t fDataId;
};
#endif