移动客户端缓存机制分析及应用研究.docx

1、移动客户端缓存机制分析及应用研究 摘 要 I G/S模式下移动客户端缓存机制分析及应用研究 作者简介：史宏宇，性别，女，1986 年 12 月生，师从成都理工大学苗放教授，2012 年 6 月毕业于成都理工大学计算机软件与理论专业，获得工学硕士学位。 摘 要 一直以来，客户端缓存技术是计算机科学中的经典技术之一，对缓存机制的分析研究是有效提高数据利用效率和提高系统性能的重要手段。随着互联网技术及无线通信技术的飞速发展，智能移动终端的使用也越来越普及，而由于移动终端本身特有的供电时间有限、移动性、网络条件不稳定及处理能力有限等特点，使得传统的客户端缓存机制无法直接应用于移动终端。本文在对移动终端

2、数据特点及已有缓存机制进行研究的基础之上，按照 G/S 模式“以数据为核心，以标识为主线”的理念，针对移动客户端缓存所特有的问题，结合空间信息具有明显的地理特征和位置相关性的特征，在缓存数据调度机制、缓存管理机制中根据地理位置特征和其他相关性等方面进行性能优化；定义数据缓存标记语言 DCML，并创建管理缓存文件的元数据库，按照统一标准对缓存数据进行管理；建立移动终端用户行为特征库统计用户地理位置和行为特征信息，通过统计分析，定义缓存文件优先级并进行动态维护，为缓存文件的调度和置换提供合理依据；设计一套应用于移动终端的存储访问模型和基于地理位置的缓存预测模型，按照缓存文件的优先级做到空间信息数据

3、精确预测预缓存和合理调度，在移动客户端实现大规模空间信息的高效聚合服务，解决空间信息网络服务模式大众化应用问题。 建立在对以上内容的研究的基础之上，本文取得的主要成果包括： （1） 设计实现了一种基于地理位置信息的空间信息缓存模型，结合空间信息的明显的地理位置特征和位置相关性的特征，对缓存数据按照统一标准进行管理和调度，实现数据的精确预缓存和高效访问，显著提高缓存命中率。 （2） 优化了移动客户端的本地数据的管理机制，设计了数据缓存标记语言DCML 作为数据交换的统一标准，并建立管理缓存文件的元数据库，对缓存文件进行标准化存储，实现在有限空间内数据的高效管理与调度应用，并基于DCML 设计实现

4、了跨平台的移动终端极端数据同步共享机制，能够充分利用移动终端近场传输的优势，在一定程度上解决了在自然灾害等重大灾害发生时的极端网络条件下数据匮乏的问题。 （3） 设计了运行于客户端的用户行为特征库，统计使用者的地理位置和行成都理工大学硕士学位论文 II为习惯信息，并对信息库内的信息进行分析统计，计算缓存文件基于多维特征的缓存优先级并进行动态维护，并通过动态适应策略模拟用户的行为习惯，提供精确的预测信息，为预测预缓存信息提供依据。 （4） 设计通过测试和实验验证了上述方法的有效性和可行性，并通过测试得到有效的数据结果支持。 针对以上成果，本文的创新点主要有以下几点： （1） 提出了一种数据缓存标

5、记语言 DCML。通过对移动终端空间信息数据特点的研究，设计了数据缓存标记语言 DCML 作为数据交换的统一标准，并基于 DCML 设计缓存管理元数据库，通过对元数据的操作，实现对多源异构缓存数据的统一组织和管理。 （2） 提出了一种以用户行为特征为基础的多维特征缓存同步更新模型。通过对用户地理位置和典型行为特征的统计，设计了可动态维护的用户行为特征库，设计多维特征的缓存优先级算法对缓存文件进行优先级管理，并针对文件优先级设计缓存置换方式，并通过用户行为特征库不断的动态更新达到精确预缓存的目的。 （3） 提出了一种基于统一数据交换标准 DCML 的短距离传输机制。针对在极端网络条件下数据匮乏的

6、问题，利用移动终端短距离通信技术的优势，设计了一种跨终端缓存共享机制，通过统一的数据交换标准 DCML，实现缓存数据的跨终端共享。 关键词：空间信息 数据缓存标记语言 缓存管理 地理位置 优先级 ABSTRACT III THE CACHE MECHANISM ANALYSIS AND APPLIED RESEARCH ABOUT THE MOBILE CLIENT-SIDE BASED ON G/S MODE INTRODUCTION OF THE AUTHOR: SHIHONGYU, FEMALE, WAS BORN IN DECEMBER, 1986 WHOSE TUTOR WAS PR

7、OFESSOR MIAOFANG. HE GRADUATED FROM CHENGDU UNIVERSITY OF TECHNOLOGY IN COMPUTER SOFTWARE AND THEORY OF A PROFESSIONAL MAJOR AND WAS GRANTED THE MASTER DEGREE IN JUNE, 2012. ABSTRACT FOR A LONG TIME, THE CLIENT CACHE IS ONE OF THE CLASSIC TECHNOLOGIES IN COMPUTER SCIENCE ANALYSIS OF THE CACHING MECH

8、ANISM IS EFFECTIVE IN IMPROVING THE EFFICIENCY OF DATA UTILIZATION AND AN IMPORTANT MEANS TO IMPROVE SYSTEM PERFORMANCE. WITH THE RAPID DEVELOPMENT OF INTERNET TECHNOLOGY AND WIRELESS COMMUNICATION TECHNOLOGY, THE USE OF INTELLIGENT MOBILE TERMINALS IS ALSO BECOMING INCREASINGLY POPULAR, DUE TO THEI

9、R UNIQUE SUPPLY TIME OF THE MOBILE TERMINAL IS LIMITED, MOBILITY, UNSTABLE NETWORK CONDITIONS AND LIMITED PROCESSING CAPACITY, MAKINGTRADITIONAL CLIENT-SIDE CACHING MECHANISM CAN NOT BE DIRECTLY APPLIED TO THE MOBILE TERMINAL. THIS PAPER MADE A THOROUGH RESEARCH ON THE DATA CHARACTERISTICS OF THE MO

10、BILE TERMINAL AND THE EXISTING CACHING MECHANISM, AND FLLOW THE PHILOSOPHY THAT DATA-CENTRIC AND WITH THE MAIN CLUE OF IDENTIFIER OF G/S MODE. DUE TO THE PROBLEMS PECULIAR TO THE MOBILE CLIENT CACHE, COMBINED WITH THE SPATIAL INFORMATION HAS OBVIOUS GEOGRAPHICAL FEATURES AND LOCATION OF FEATURES, WE

11、 STUDY PERFORMANCE OPTIMIZATION IN THE CACHE DATA SCHEDULING MECHANISM AND BUFFER MANAGEMENT MECHANISM BASED ON THAT MENTIONED ABOVE. WE DEFINED THE DATA CACHE MARKUP LANGUAGE (DCML), AND CREATE MANAGEMENT CACHE FILE DATABASE TO MANAGE THE CACHED DATA IN ACCORDANCE WITH UNIFORM STANDARDS. BESIDES, W

12、E BUILD THE CHARACTERISTICS OF INFORMATION TO ESTABLISH THE LOCATION AND BEHAVIOR OF THE MOBILE END-USER BEHAVIOR CHARACTERISTICS OF LIBRARY USERS OF STATISTICS, THROUGH STATISTICAL ANALYSIS, DEFINE THE PRIORITY OF THE CACHE FILES AND DYNAMIC MAINTENANCE SCHEDULING AND REPLACEMENT OF THE CACHE FILE

13、TO PROVIDE A REASONABLE BASIS. WE ALSO DESIGN A STORAGE ACCESS MODEL AND LOCATION-BASED CACHE PREDICTION MODEL APPLIED TO THE MOBILE TERMINAL. IN ACCORDANCE WITH THE PRIORITY OF THE CACHE FILES TO ACCURATELY PREDICT PRE-CACHE AND RATIONAL MANAGEMENT TO THE SPATIAL INFORMATION DATA. AND EFFICIENT LAR

14、GE-SCALE SPATIAL INFORMATION AGGREGATION SERVICE IN MOBILE CLIENT ADDRESS SPACE INFORMATION NETWORK SERVICE MODEL POPULAR APPLICATION 成都理工大学硕士学位论文 IV PROBLEMS. BASED ON THE RESEARCH MENTIONED ABOVE , THE PRIMARY ACHIEVEMENTS IN THIS PAPER WERE： (1) IN THIS PAPER，WE DESIGNED A SPATIAL INFORMATION CAC

15、HE MODEL BASED ON THE GEO-LOCATION INFORMATION . ACCORDING TO THE GEO-LOCATION AND LOCATION CORRELATION FEATURES OF SPATIAL INFORMATION, THE CACHE WAS MANAGED AND SCHEDULED IN THE CERTAIN STANDARDS. SO, THE DATA CAN BE PRELOAD CACHED PRECISELY AND ACCESSED EFFCIENTLY. (2) IN THIS PAPER, THE MANAGEME

16、NT MECHANISM OF THE MOBILE CLIENT FOR THE LOCAL DATA GOT OPTIMIZED, THE DATA CACHE MARKUP LANGUAGE (DCML) FOR THE PURPOSE OF BEING THE UNIQUE DATA TRANSFORMING STANDARD GOT DESIGNED, AND THE METADATABASE FOR MANAGING THE CACHE GOT ESTABLISHED. THE CACHE GOT STORED UNDER THE STANDARD, MANAGED AND SCH

17、EDULED IN A LIMITE STORAGE SPACE. AND THE SYNC AND SHARE MECHANISM OF EXTREME DATA ON THE MOBILE CLIENT GOT DESIGNED BASED ON DCML; IT CAN USE THE ADVANTAGE OF NEAR FIELD TRANEMISSON. SO, THE LACK OF DATA IN THE EXTREME NET ENVIRONMENT WHEN THE NATURAL DISASTERS HAPPEN CAN BE SOLVED IN A CERTAIN EXT

18、ENT. (3) IN THIS PAPER, THE USER BEHAVIOUR FEATURE LIBRARY FOR THE CLIENT GOT DESIGNED, THE GEO-LOCATION AND BEHAVIOR INFORMATIONS OF USERS GOT COUNTED, AND THE INFORMATIONS IN THE LIBRARY GOT ANALYSED. MEANWHILE, THE CACHE PRIORITY BASED ON THE MULTI-FEATURES GOT COMPUTED AND MAINTAINED DYNAMICALLY

19、, THE DYNAMIC ADAPTIVE STRATEGIES IMITATED THE BEHAVIORAL HABIT OF USERS. SO, IT CAN PROVIDE PREDICTION FOR THE PRELOAD CACHE. (4) IN THIS PAPER, THE RESEARCH TESTED THE EFFICIENCY AND FEASIBILITY OF THE METHOD ABOVE, AND GOT SOME TESTING RESULTS FOR SUPPORTING. THE MAIN INNOVATIONS OF THIS PAPER AR

20、E FOLLOWING: (1) WE PROPOSED AND DESIGNED A DATA CACHE MARKUP LANGUAGE DCML. THROUGH STUDIED ON THE CHARACTERISTICS OF SPACE INFORMATION DATA OF THE MOBILE TERMINAL, WE DESIGN THE DATA CACHE MARKUP LANGUAGE (DCML) AS A UNIFIED DATA EXCHANGE STANDARD, AND DESIGN CACHE MANAGEMENT METABASE BASED ON THE

21、 THE DCML. BY OPERATING ON METADATA, WE CAN UNIFIED ORGANIZATE AND MANAGE HETEROGENEOUS CACHE DATA FROM MULTIPLE SOURCES. (2) WE PROPOSED AND DESIGNED THE MULTI-DIMENSIONAL CHARACTERISTICS OF CACHE SYNCHRONIZATION TO UPDATE THE MODEL BASED ON USER BEHAVIOR CHARACTERISTICS. WE PROPOSED AND DESIGNED T

22、HE MULTI-DIMENSIONAL CHARACTERISTICS OF CACHE SYNCHRONIZATION TO UPDATE THE MODEL BASED ON USER BEHAVIOR CHARACTERISTICS. BY STATISTICING ON USER LOCATION AND TYPICAL BEHAVIORAL CHARACTERISTICS, WE DESIGN DATABASE ABOUT USER BEHAVIOR CHARACTERISTICS THAT CAN BE DYNAMICALLY MAINTAINED, AND DESIGN A A

23、BSTRACT V MULTI-DIMENSIONAL PRIORITY ALGORITHM TO MANAGE CACHE FILES. BESIDES, WE CAN DO THE ACHE REPLACEMENT FOR THE FILE PRIORITY AND THROUGH USER BEHAVIOR CHARACTERISTICS OF THE LIBRARY CONSTANTLY UPDATED DYNAMICALLY TO ACHIEVE THE PURPOSE OF ACCURATE PRE-CACHE. (3) THIS PAPER PRESENTS A SHORT DI

24、STANCE TRANSMISSION MECHANISM BASED ON UNIFIED DATA EXCHANGE STANDARD DCML. IN THE EXTREME CONDITION OF NETWORK DATA SCARCITY PROBLEM,A CROSS TERMINAL BUFFER SHARING MECHANISM HAS DESIGNED BY USING SHORT DISTANCE COMMUNICATION TECHNOLOGY ADVANTAGES OF MOBILE TERMINAL,WHICH REALIZE THE CACHE DATA ACR

25、OSS TERMINALS SHARE THROUGH A UNIFIED DATA EXCHANGE STANDARD DCML. KEYWORDS: SPATIAL INFORMATION DATA CACHE MARKUP LANGUAGE CACHE MANAGEMENT LOCATION PRIORITY 目 录 I 目 录 摘 要 . I ABSTRACT .III 第1章 引 言 . 1 1.1课题来源. 1 1.2选题的目的和意义 . 1 1.2.1 选题目的 . 1 1.2.2 选题意义 . 1 1.3国内外研究现状及不足之处 . 2 1.4本文研究内容及技术路线. 3 1.4.1 研究内容 . 3 1.4.2 技术路线 . 4 1.5 论文取得的主要研究成果. 5 1.6论文创新点 . 6 1.7 论文组织结构 . 6 2.1 移动环境下的空间信息网络访问模式-G/S模式. 8 2.1.1 G/S 模式的概述 . 8 2.1.2 G/S 模式的特点及优势 . 8 2.2 G/S模式下的空间数据交换标准HGML . 9 2.3 移动计算环境下的缓存管理技术研究 .10 第3章 移动客户端数据特点研究及数据缓存标记语言DCML设计 .12 3.1 移动客户端特点研究 .12 3.1.1 移动计算环境研究 .