1/* 2 3"Special" Cache. 4 5Copyright (c) 2003 OpenBeOS. 6 7Author: 8 Michael Pfeiffer 9 10Permission is hereby granted, free of charge, to any person obtaining a copy of 11this software and associated documentation files (the "Software"), to deal in 12the Software without restriction, including without limitation the rights to 13use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies 14of the Software, and to permit persons to whom the Software is furnished to do 15so, subject to the following conditions: 16 17The above copyright notice and this permission notice shall be included in all 18copies or substantial portions of the Software. 19 20THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR 21IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, 22FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE 23AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER 24LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, 25OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN 26THE SOFTWARE. 27 28*/ 29 30#include "Report.h" 31#include "Cache.h" 32#include <Debug.h> 33 34class CIReference : public CacheItem { 35public: 36 CIReference(CacheItem* item) : fItem(item) { 37 ASSERT(dynamic_cast<CIReference*>(item) == NULL); 38 } 39 40 bool Equals(CIDescription* desc) const { 41 return fItem->Equals(desc); 42 } 43 44 CacheItem* Reference() { 45 return fItem; 46 } 47 48private: 49 CacheItem* fItem; 50}; 51 52Cache::Cache() 53 : fPass(0) 54 , fNextID(0) 55{}; 56 57void Cache::NextPass() { 58 fPass++; 59 fNextID = 0; 60 // max two passes! 61 ASSERT(fPass == 1); 62} 63 64CacheItem* Cache::Find(CIDescription* desc) { 65 REPORT(kDebug, -1, "Cache::Find() pass = %d next id = %d", fPass, fNextID); 66 int id = fNextID ++; 67 const int32 n = CountItems(); 68 CacheItem* item = ItemAt(id); 69 70 // In 2. pass for each item an entry must exists 71 ASSERT(fPass != 1 || item != NULL); 72 if (fPass == 1) return item->Reference(); 73 74 // In 1. pass we create an entry for each bitmap 75 for (int32 i = 0; i < n; i ++) { 76 item = ItemAt(i); 77 // skip references 78 if (item != item->Reference()) continue; 79 if (item->Equals(desc)) { 80 // found item in cache, create a reference to it 81 CacheItem* ref = new CIReference(item->Reference()); 82 if (ref == NULL) return NULL; 83 fCache.AddItem(ref); 84 return item; 85 } 86 } 87 // item not in cache, create one 88 item = desc->NewItem(id); 89 if (item != NULL) { 90 ASSERT(dynamic_cast<CIReference*>(item) == NULL); 91 fCache.AddItem(item); 92 } 93 return item; 94} 95