Dynamic Array an Array-Based Implementation - Summary Good Things
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Application of TRIE Data Structure and Corresponding Associative Algorithms for Process Optimization in GRID Environment
Application of TRIE data structure and corresponding associative algorithms for process optimization in GRID environment V. V. Kashanskya, I. L. Kaftannikovb South Ural State University (National Research University), 76, Lenin prospekt, Chelyabinsk, 454080, Russia E-mail: a [email protected], b [email protected] Growing interest around different BOINC powered projects made volunteer GRID model widely used last years, arranging lots of computational resources in different environments. There are many revealed problems of Big Data and horizontally scalable multiuser systems. This paper provides an analysis of TRIE data structure and possibilities of its application in contemporary volunteer GRID networks, including routing (L3 OSI) and spe- cialized key-value storage engine (L7 OSI). The main goal is to show how TRIE mechanisms can influence de- livery process of the corresponding GRID environment resources and services at different layers of networking abstraction. The relevance of the optimization topic is ensured by the fact that with increasing data flow intensi- ty, the latency of the various linear algorithm based subsystems as well increases. This leads to the general ef- fects, such as unacceptably high transmission time and processing instability. Logically paper can be divided into three parts with summary. The first part provides definition of TRIE and asymptotic estimates of corresponding algorithms (searching, deletion, insertion). The second part is devoted to the problem of routing time reduction by applying TRIE data structure. In particular, we analyze Cisco IOS switching services based on Bitwise TRIE and 256 way TRIE data structures. The third part contains general BOINC architecture review and recommenda- tions for highly-loaded projects. -
CS 106X, Lecture 21 Tries; Graphs
CS 106X, Lecture 21 Tries; Graphs reading: Programming Abstractions in C++, Chapter 18 This document is copyright (C) Stanford Computer Science and Nick Troccoli, licensed under Creative Commons Attribution 2.5 License. All rights reserved. Based on slides created by Keith Schwarz, Julie Zelenski, Jerry Cain, Eric Roberts, Mehran Sahami, Stuart Reges, Cynthia Lee, Marty Stepp, Ashley Taylor and others. Plan For Today • Tries • Announcements • Graphs • Implementing a Graph • Representing Data with Graphs 2 Plan For Today • Tries • Announcements • Graphs • Implementing a Graph • Representing Data with Graphs 3 The Lexicon • Lexicons are good for storing words – contains – containsPrefix – add 4 The Lexicon root the art we all arts you artsy 5 The Lexicon root the contains? art we containsPrefix? add? all arts you artsy 6 The Lexicon S T A R T L I N G S T A R T 7 The Lexicon • We want to model a set of words as a tree of some kind • The tree should be sorted in some way for efficient lookup • The tree should take advantage of words containing each other to save space and time 8 Tries trie ("try"): A tree structure optimized for "prefix" searches struct TrieNode { bool isWord; TrieNode* children[26]; // depends on the alphabet }; 9 Tries isWord: false a b c d e … “” isWord: true a b c d e … “a” isWord: false a b c d e … “ac” isWord: true a b c d e … “ace” 10 Reading Words Yellow = word in the trie A E H S / A E H S A E H S A E H S / / / / / / / / A E H S A E H S A E H S A E H S / / / / / / / / / / / / A E H S A E H S A E H S / / / / / / / -
Introduction to Linked List: Review
Introduction to Linked List: Review Source: http://www.geeksforgeeks.org/data-structures/linked-list/ Linked List • Fundamental data structures in C • Like arrays, linked list is a linear data structure • Unlike arrays, linked list elements are not stored at contiguous location, the elements are linked using pointers Array vs Linked List Why Linked List-1 • Advantages over arrays • Dynamic size • Ease of insertion or deletion • Inserting a new element in an array of elements is expensive, because room has to be created for the new elements and to create room existing elements have to be shifted For example, in a system if we maintain a sorted list of IDs in an array id[]. id[] = [1000, 1010, 1050, 2000, 2040] If we want to insert a new ID 1005, then to maintain the sorted order, we have to move all the elements after 1000 • Deletion is also expensive with arrays until unless some special techniques are used. For example, to delete 1010 in id[], everything after 1010 has to be moved Why Linked List-2 • Drawbacks of Linked List • Random access is not allowed. • Need to access elements sequentially starting from the first node. So we cannot do binary search with linked lists • Extra memory space for a pointer is required with each element of the list Representation in C • A linked list is represented by a pointer to the first node of the linked list • The first node is called head • If the linked list is empty, then the value of head is null • Each node in a list consists of at least two parts 1. -
University of Cape Town Declaration
The copyright of this thesis vests in the author. No quotation from it or information derived from it is to be published without full acknowledgementTown of the source. The thesis is to be used for private study or non- commercial research purposes only. Cape Published by the University ofof Cape Town (UCT) in terms of the non-exclusive license granted to UCT by the author. University Automated Gateware Discovery Using Open Firmware Shanly Rajan Supervisor: Prof. M.R. Inggs Co-supervisor: Dr M. Welz University of Cape Town Declaration I understand the meaning of plagiarism and declare that all work in the dissertation, save for that which is properly acknowledged, is my own. It is being submitted for the degree of Master of Science in Engineering in the University of Cape Town. It has not been submitted before for any degree or examination in any other university. Signature of Author . Cape Town South Africa May 12, 2013 University of Cape Town i Abstract This dissertation describes the design and implementation of a mechanism that automates gateware1 device detection for reconfigurable hardware. The research facilitates the pro- cess of identifying and operating on gateware images by extending the existing infrastruc- ture of probing devices in traditional software by using the chosen technology. An automated gateware detection mechanism was devised in an effort to build a software system with the goal to improve performance and reduce software development time spent on operating gateware pieces by reusing existing device drivers in the framework of the chosen technology. This dissertation first investigates the system design to see how each of the user specifica- tions set for the KAT (Karoo Array Telescope) project in [28] could be achieved in terms of design decisions, toolchain selection and software modifications. -
Yikes! Why Is My Systemverilog Still So Slooooow?
DVCon-2019 San Jose, CA Voted Best Paper 1st Place World Class SystemVerilog & UVM Training Yikes! Why is My SystemVerilog Still So Slooooow? Cliff Cummings John Rose Adam Sherer Sunburst Design, Inc. Cadence Design Systems, Inc. Cadence Design System, Inc. [email protected] [email protected] [email protected] www.sunburst-design.com www.cadence.com www.cadence.com ABSTRACT This paper describes a few notable SystemVerilog coding styles and their impact on simulation performance. Benchmarks were run using the three major SystemVerilog simulation tools and those benchmarks are reported in the paper. Some of the most important coding styles discussed in this paper include UVM string processing and SystemVerilog randomization constraints. Some coding styles showed little or no impact on performance for some tools while the same coding styles showed large simulation performance impact. This paper is an update to a paper originally presented by Adam Sherer and his co-authors at DVCon in 2012. The benchmarking described in this paper is only for coding styles and not for performance differences between vendor tools. DVCon 2019 Table of Contents I. Introduction 4 Benchmarking Different Coding Styles 4 II. UVM is Software 5 III. SystemVerilog Semantics Support Syntax Skills 10 IV. Memory and Garbage Collection – Neither are Free 12 V. It is Best to Leave Sleeping Processes to Lie 14 VI. UVM Best Practices 17 VII. Verification Best Practices 21 VIII. Acknowledgment 25 References 25 Author & Contact Information 25 Page 2 Yikes! Why is -
Linux Kernel and Driver Development Training Slides
Linux Kernel and Driver Development Training Linux Kernel and Driver Development Training © Copyright 2004-2021, Bootlin. Creative Commons BY-SA 3.0 license. Latest update: October 9, 2021. Document updates and sources: https://bootlin.com/doc/training/linux-kernel Corrections, suggestions, contributions and translations are welcome! embedded Linux and kernel engineering Send them to [email protected] - Kernel, drivers and embedded Linux - Development, consulting, training and support - https://bootlin.com 1/470 Rights to copy © Copyright 2004-2021, Bootlin License: Creative Commons Attribution - Share Alike 3.0 https://creativecommons.org/licenses/by-sa/3.0/legalcode You are free: I to copy, distribute, display, and perform the work I to make derivative works I to make commercial use of the work Under the following conditions: I Attribution. You must give the original author credit. I Share Alike. If you alter, transform, or build upon this work, you may distribute the resulting work only under a license identical to this one. I For any reuse or distribution, you must make clear to others the license terms of this work. I Any of these conditions can be waived if you get permission from the copyright holder. Your fair use and other rights are in no way affected by the above. Document sources: https://github.com/bootlin/training-materials/ - Kernel, drivers and embedded Linux - Development, consulting, training and support - https://bootlin.com 2/470 Hyperlinks in the document There are many hyperlinks in the document I Regular hyperlinks: https://kernel.org/ I Kernel documentation links: dev-tools/kasan I Links to kernel source files and directories: drivers/input/ include/linux/fb.h I Links to the declarations, definitions and instances of kernel symbols (functions, types, data, structures): platform_get_irq() GFP_KERNEL struct file_operations - Kernel, drivers and embedded Linux - Development, consulting, training and support - https://bootlin.com 3/470 Company at a glance I Engineering company created in 2004, named ”Free Electrons” until Feb. -
WLFC: Write Less in the Flash-Based Cache
WLFC: Write Less in the Flash-based Cache Chaos Dong Fang Wang Jianshun Zhang Huazhong University of Huazhong University of Huazhong University of Science and Technology Science and Technology Science and Technology Huhan, China Huhan, China Huhan, China Email: [email protected] Email: [email protected] Email: [email protected] Abstract—Flash-based disk caches, for example Bcache [1] and log-on-log [5]. At the same time, the Open-Channel SSD Flashcache [2], has gained tremendous popularity in industry (OCSSD) has became increasingly popular in academia. in the last decade because of its low energy consumption, non- Through a standard OCSSD interface, the behaviors of the volatile nature and high I/O speed. But these cache systems have a worse write performance than the read performance because flash memory can be managed by the host to improve the of the asymmetric I/O costs and the the internal GC mechanism. utilization of the storage. In addition to the performance issues, since the NAND flash is In this paper, we mainly make three contributions to optimize a type of EEPROM device, the lifespan is also limited by the write performance of the flash-based disk cache. First, we Program/Erase (P/E) cycles. So how to improve the performance designed a write-friendly flash-based disk cache system and the lifespan of flash-based caches in write-intensive scenarios has always been a hot issue. Benefiting from Open-Channel SSDs upon Open-Channel SSDs, named WLFC (Write Less in (OCSSDs) [3], we propose a write-friendly flash-based disk cache the Flash-based Cache), in which the requests is handled system, which is called WLFC (Write Less in the Flash-based by a strictly sequential writing method to reduce write Cache). -
Lecture 2: Data Structures: a Short Background
Lecture 2: Data structures: A short background Storing data It turns out that depending on what we wish to do with data, the way we store it can have a signifcant impact on the running time. So in particular, storing data in certain "structured" way can allow for fast implementation. This is the motivation behind the feld of data structures, which is an extensive area of study. In this lecture, we will give a very short introduction, by illustrating a few common data structures, with some motivating problems. In the last lecture, we mentioned that there are two ways of representing graphs (adjacency list and adjacency matrix), each of which has its own advantages and disadvantages. The former is compact (size is proportional to the number of edges + number of vertices), and is faster for enumerating the neighbors of a vertex (which is what one needs for procedures like Breadth-First-Search). The adjacency matrix is great if one wishes to quickly tell if two vertices and have an edge between them. Let us now consider a diferent problem. Example 1: Scrabble problem Suppose we have a "dictionary" of strings whose average length is , and suppose we have a query string . How can we quickly tell if ? Brute force. Note that the naive solution is to iterate over the strings and check if for some . This takes time . If we only care about answering the query for one , this is not bad, as is the amount of time needed to "read the input". But of course, if we have a fxed dictionary and if we wish to check if for multiple , then this is extremely inefcient. -
Implementing the Map ADT Outline
Implementing the Map ADT Outline ´ The Map ADT ´ Implementation with Java Generics ´ A Hash Function ´ translation of a string key into an integer ´ Consider a few strategies for implementing a hash table ´ linear probing ´ quadratic probing ´ separate chaining hashing ´ OrderedMap using a binary search tree The Map ADT ´A Map models a searchable collection of key-value mappings ´A key is said to be “mapped” to a value ´Also known as: dictionary, associative array ´Main operations: insert, find, and delete Applications ´ Store large collections with fast operations ´ For a long time, Java only had Vector (think ArrayList), Stack, and Hashmap (now there are about 67) ´ Support certain algorithms ´ for example, probabilistic text generation in 127B ´ Store certain associations in meaningful ways ´ For example, to store connected rooms in Hunt the Wumpus in 335 The Map ADT ´A value is "mapped" to a unique key ´Need a key and a value to insert new mappings ´Only need the key to find mappings ´Only need the key to remove mappings 5 Key and Value ´With Java generics, you need to specify ´ the type of key ´ the type of value ´Here the key type is String and the value type is BankAccount Map<String, BankAccount> accounts = new HashMap<String, BankAccount>(); 6 put(key, value) get(key) ´Add new mappings (a key mapped to a value): Map<String, BankAccount> accounts = new TreeMap<String, BankAccount>(); accounts.put("M",); accounts.put("G", new BankAcnew BankAccount("Michel", 111.11)count("Georgie", 222.22)); accounts.put("R", new BankAccount("Daniel", -
Algorithms & Data Structures: Questions and Answers: May 2006
Algorithms & Data Structures: Questions and Answers: May 2006 1. (a) Explain how to merge two sorted arrays a1 and a2 into a third array a3, using diagrams to illustrate your answer. What is the time complexity of the array merge algorithm? (Note that you are not asked to write down the array merge algorithm itself.) [Notes] First compare the leftmost elements in a1 and a2, and copy the lesser element into a3. Repeat, ignoring already-copied elements, until all elements in either a1 or a2 have been copied. Finally, copy all remaining elements from either a1 or a2 into a3. Loop invariant: left1 … i–1 i … right1 a1 already copied still to be copied left2 … j–1 j … right2 a2 left left+1 … k–1 k … right–1 right a3 already copied unoccupied Time complexity is O(n), in terms of copies or comparisons, where n is the total length of a1 and a2. (6) (b) Write down the array merge-sort algorithm. Use diagrams to show how this algorithm works. What is its time complexity? [Notes] To sort a[left…right]: 1. If left < right: 1.1. Let mid be an integer about midway between left and right. 1.2. Sort a[left…mid]. 1.3. Sort a[mid+1…right]. 1.4. Merge a[left…mid] and a[mid+1…right] into an auxiliary array b. 1.5. Copy b into a[left…right]. 2. Terminate. Invariants: left mid right After step 1.1: a unsorted After step 1.2: a sorted unsorted After step 1.3: a sorted sorted After step 1.5: a sorted Time complexity is O(n log n), in terms of comparisons. -
FORSCHUNGSZENTRUM JÜLICH Gmbh Programming in C++ Part II
FORSCHUNGSZENTRUM JÜLICH GmbH Jülich Supercomputing Centre D-52425 Jülich, Tel. (02461) 61-6402 Ausbildung von Mathematisch-Technischen Software-Entwicklern Programming in C++ Part II Bernd Mohr FZJ-JSC-BHB-0155 1. Auflage (letzte Änderung: 19.09.2003) Copyright-Notiz °c Copyright 2008 by Forschungszentrum Jülich GmbH, Jülich Supercomputing Centre (JSC). Alle Rechte vorbehalten. Kein Teil dieses Werkes darf in irgendeiner Form ohne schriftliche Genehmigung des JSC reproduziert oder unter Verwendung elektronischer Systeme verarbeitet, vervielfältigt oder verbreitet werden. Publikationen des JSC stehen in druckbaren Formaten (PDF auf dem WWW-Server des Forschungszentrums unter der URL: <http://www.fz-juelich.de/jsc/files/docs/> zur Ver- fügung. Eine Übersicht über alle Publikationen des JSC erhalten Sie unter der URL: <http://www.fz-juelich.de/jsc/docs> . Beratung Tel: +49 2461 61 -nnnn Auskunft, Nutzer-Management (Dispatch) Das Dispatch befindet sich am Haupteingang des JSC, Gebäude 16.4, und ist telefonisch erreich- bar von Montag bis Donnerstag 8.00 - 17.00 Uhr Freitag 8.00 - 16.00 Uhr Tel.5642oder6400, Fax2810, E-Mail: [email protected] Supercomputer-Beratung Tel. 2828, E-Mail: [email protected] Netzwerk-Beratung, IT-Sicherheit Tel. 6440, E-Mail: [email protected] Rufbereitschaft Außerhalb der Arbeitszeiten (montags bis donnerstags: 17.00 - 24.00 Uhr, freitags: 16.00 - 24.00 Uhr, samstags: 8.00 - 17.00 Uhr) können Sie dringende Probleme der Rufbereitschaft melden: Rufbereitschaft Rechnerbetrieb: Tel. 6400 Rufbereitschaft Netzwerke: Tel. 6440 An Sonn- und Feiertagen gibt es keine Rufbereitschaft. Fachberater Tel. +49 2461 61 -nnnn Fachgebiet Berater Telefon E-Mail Auskunft, Nutzer-Management, E. -
Chapter 10: Efficient Collections (Skip Lists, Trees)
Chapter 10: Efficient Collections (skip lists, trees) If you performed the analysis exercises in Chapter 9, you discovered that selecting a bag- like container required a detailed understanding of the tasks the container will be expected to perform. Consider the following chart: Dynamic array Linked list Ordered array add O(1)+ O(1) O(n) contains O(n) O(n) O(log n) remove O(n) O(n) O(n) If we are simply considering the cost to insert a new value into the collection, then nothing can beat the constant time performance of a simple dynamic array or linked list. But if searching or removals are common, then the O(log n) cost of searching an ordered list may more than make up for the slower cost to perform an insertion. Imagine, for example, an on-line telephone directory. There might be several million search requests before it becomes necessary to add or remove an entry. The benefit of being able to perform a binary search more than makes up for the cost of a slow insertion or removal. What if all three bag operations are more-or-less equal? Are there techniques that can be used to speed up all three operations? Are arrays and linked lists the only ways of organizing a data for a bag? Indeed, they are not. In this chapter we will examine two very different implementation techniques for the Bag data structure. In the end they both have the same effect, which is providing O(log n) execution time for all three bag operations.