【摘要】：Java智能卡已經(jīng)逐漸被廣泛應用于銀行、通信等安全性要求很高的領(lǐng)域中。但是受限于當前智能卡的硬件資源，特別是多應用智能卡的流行，卡片的存儲資源越來越受到重視，Java卡虛擬機的具體實現(xiàn)方式和相關(guān)機制也嚴重影響了卡片的執(zhí)行效率。因此，對卡片中得存儲管理進行優(yōu)化改進是十分必要的。在分析了Sun公司給出的Java卡EEPROM的管理算法之后，總結(jié)出現(xiàn)有算法的缺陷，，提出了一種帶碎片整理的EEPROM管理算法。 研究Java卡EEPROM的存儲管理方式，對存儲方式改進，能提高其存儲效率。首先通過分析Java卡的寫操作機制以及Sun公司的Java卡參考實現(xiàn)中EEPROM管理方式，發(fā)現(xiàn)其存在存儲碎片多，空閑空間不連續(xù)，存儲效率不高等缺陷。然后針對上述的缺陷對EEPROM的結(jié)構(gòu)重新設(shè)計，在EEPROM的結(jié)構(gòu)中設(shè)置了一些重要的標志位，提出一種帶碎片整理的存儲管理方式，詳細敘述此方式下的空間分配、空間釋放算法以及放拔掉電處理。最后給出了這種帶碎片整理的EEPROM管理算法的實現(xiàn)，通過相關(guān)實驗測試，EEPROM的空間分配、釋放都能正常進行，并且在EEPROM完成碎片整理后，其空閑頁都能有效的緊湊到存儲器的尾部，為下次的存儲提供最大化的連續(xù)空閑空間，表明此EEPROM的管理方式是高效可行的，并提出了一些進一步改進效率的建議和展望。
[Abstract]:Java smart card has been widely used in banks, communications and other areas with high security requirements. However, limited by the current smart card hardware resources, especially the popularity of multi-application smart cards, more and more attention has been paid to the memory resources of cards, the implementation of Java card virtual machines and related mechanisms have also seriously affected the efficiency of card execution. Therefore, it is necessary to optimize the storage management in cards. After analyzing the management algorithm of Java card EEPROM proposed by Sun Company, this paper summarizes the defects of the algorithm, and puts forward a EEPROM management algorithm with defragmentation. The storage management mode of Java card EEPROM is studied. The storage efficiency can be improved by improving the storage mode. Firstly, by analyzing the writing operation mechanism of Java card and the EEPROM management mode in the Java card reference implementation of Sun Company, it is found that there are many defects such as more storage fragments, discontinuous free space and low storage efficiency. Then, aiming at the defects mentioned above, the structure of EEPROM is redesigned, and some important flag bits are set up in the structure of EEPROM. A storage management method with defragmentation is proposed, and the space allocation under this mode is described in detail. Space release algorithm and discharge unplug processing. Finally, the implementation of this EEPROM management algorithm with defragmentation is given. The space allocation of EEPROM is tested by relevant experiments, the release can be carried out normally, and after EEPROM defragmentation, its free pages can be effectively compact to the end of memory. It shows that the management method of this EEPROM is efficient and feasible, and puts forward some suggestions and prospects for further improving the efficiency.
【學位授予單位】：華中科技大學
【學位級別】：碩士
【學位授予年份】：2013
【分類號】：TP333

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本文編號：2241697