BorlandTalk.com Borland discussion newsgroups   Archives   FAQ   Search   Memberlist   Usergroups   Register   Profile   Log in to check your private messages   Log in  Any known fast hash algorithms ?          BorlandTalk.com Forum Index -> Delphi Language BASM View previous topic :: View next topic   Author Message Juhani Suhonen Guest Posted: Thu May 17, 2007 9:00 pm    Post subject: Any known fast hash algorithms ? I need very fast hashing function for arbitrary length strings in type of function hash(constr str:string):longword dispersion probability is not big problem since I'm using results in stringhash table which validates inputs if similar value already exists, tia Juhani Suhonen btw. I'm currently using (from Mr. Diazgov) --- function Q_StrHashKey(const S: string): LongWord; asm TEST EAX,EAX JE @@qt LEA EDX,[EAX-1] MOV ECX,[EAX-4] XOR EAX,EAX TEST ECX,ECX JE @@qt PUSH ESI PUSH EBX @@lp: MOV ESI,EAX SHL EAX,5 MOVZX EBX,BYTE PTR [EDX+ECX] ADD EAX,ESI ADD EAX,EBX DEC ECX JNE @@lp POP EBX POP ESI @@qt: end; Back to top Davy Landman Guest Posted: Thu May 17, 2007 11:37 pm    Post subject: Re: Any known fast hash algorithms ? elf hash? by Aleksandr Sharahov: function ElfHash_Sha(const s: string): integer; asm mov edx, eax xor eax, eax test edx, edx jz @Ret sub eax, [edx-4] jz @Ret mov ecx, eax sub edx, eax xor eax, eax push ebx @Loop: movzx ebx, [edx+ecx] add ebx, eax lea eax, [ebx+ebx] shr ebx, 20 lea eax, [8*eax] and ebx, $0F00 xor eax, ebx add ecx, 1 jnz @Loop shr eax, 4 pop ebx @Ret: end; a very good hashing function y Paul Heish: http://www.azillionmonkeys.com/qed/hash.html" Quote: Update(6): In Google's open source "sparse hash table" project, the documentation makes the following observation: " ... in one test of the default SGI STL string hash function against the Hsieh hash function ..., for a particular set of string keys, the Hsieh function resulted in hashtable lookups that were 20 times as fast as the STLPort hash function. The string keys were chosen to be "hard" to hash well, so these results may not be typical, but they are suggestive." "Juhani Suhonen" <juhani.suhonen (AT) a1netti (DOT) cmo> wrote in message news:464c7c2b (AT) newsgroups (DOT) borland.com... Quote: I need very fast hashing function for arbitrary length strings in type of function hash(constr str:string):longword dispersion probability is not big problem since I'm using results in stringhash table which validates inputs if similar value already exists, tia Juhani Suhonen btw. I'm currently using (from Mr. Diazgov) --- function Q_StrHashKey(const S: string): LongWord; asm TEST EAX,EAX JE @@qt LEA EDX,[EAX-1] MOV ECX,[EAX-4] XOR EAX,EAX TEST ECX,ECX JE @@qt PUSH ESI PUSH EBX @@lp: MOV ESI,EAX SHL EAX,5 MOVZX EBX,BYTE PTR [EDX+ECX] ADD EAX,ESI ADD EAX,EBX DEC ECX JNE @@lp POP EBX POP ESI @@qt: end; Back to top danny heijl Guest Posted: Sat May 19, 2007 2:11 am    Post subject: Re: Any known fast hash algorithms ? Juhani Suhonen schreef: Quote: I need very fast hashing function for arbitrary length strings in type of function hash(constr str:string):longword dispersion probability is not big problem since I'm using results in stringhash table which validates inputs if similar value already exists, I implemented Bob Jenkins' Lookup2 hash function in Pascal when I had to write a high-performance hashtable (holding millions of entries). Lookup2 is very fast with nearly perfect distribution for strings of any size. It has been in use for several years now performing millions of hashses a day for me. Danny --- Back to top Juhani Suhonen Guest Posted: Sat May 19, 2007 3:46 pm    Post subject: Re: Any known fast hash algorithms ? Any fast basm implementations available ? Juhani Suhonen "danny heijl" <danny_dot_heijl_at_telenet_dot_be> wrote in message news:464e1676$1 (AT) newsgroups (DOT) borland.com... Quote: Juhani Suhonen schreef: I need very fast hashing function for arbitrary length strings in type of function hash(constr str:string):longword dispersion probability is not big problem since I'm using results in stringhash table which validates inputs if similar value already exists, I implemented Bob Jenkins' Lookup2 hash function in Pascal when I had to write a high-performance hashtable (holding millions of entries). Lookup2 is very fast with nearly perfect distribution for strings of any size. It has been in use for several years now performing millions of hashses a day for me. Danny --- Back to top danny heijl Guest Posted: Sat May 19, 2007 6:40 pm    Post subject: Re: Any known fast hash algorithms ? Juhani Suhonen schreef: Quote: Any fast basm implementations available ? Not that I know of, and the code generated by the compiler is good enough for me (although I made some tweaks after inspecting the generated code in the CPU window). Danny --- Back to top Juhani Suhonen Guest Posted: Sat May 19, 2007 11:16 pm    Post subject: Re: Any known fast hash algorithms ? Could you share it ? (my basm skills are bit rusted, but i'll try my best later today evening...) Juhani Suhonen "danny heijl" <danny_dot_heijl_at_telenet_dot_be> wrote in message news:464efe5f (AT) newsgroups (DOT) borland.com... Quote: Juhani Suhonen schreef: Any fast basm implementations available ? Not that I know of, and the code generated by the compiler is good enough for me (although I made some tweaks after inspecting the generated code in the CPU window). Danny --- Back to top danny heijl Guest Posted: Sun May 20, 2007 6:14 pm    Post subject: Re: Any known fast hash algorithms ? Juhani Suhonen schreef: Quote: Could you share it ? (my basm skills are bit rusted, but i'll try my best later today evening...) I didn't use any basm, just tweaked the Pascal code a bit based on what I saw in the CPU view. My Pascal version should be in your mailbox. Danny --- Back to top Q Correll Guest Posted: Sun May 20, 2007 11:55 pm    Post subject: Re: Any known fast hash algorithms ? danny, | My Pascal version should be in your mailbox. Would you please consider passing it along to me as well? I USED to write my own hashing functions. <g. TIA, -- Q 05/20/2007 11:54:42 XanaNews Version 1.17.5.7 [Q's salutation mod] Back to top danny heijl Guest Posted: Mon May 21, 2007 12:15 am    Post subject: Re: Any known fast hash algorithms ? Q Correll schreef: Quote: Would you please consider passing it along to me as well? done danny --- Back to top Juhani Suhonen Guest Posted: Mon May 21, 2007 9:45 pm    Post subject: Re: Any known fast hash algorithms ? Could you please repost (my correct mail address is) juhani <dot> suhonen <at> a1netti <dot> com tia.... Juhani Suhonen "danny heijl" <danny_dot_heijl_at_telenet_dot_be> wrote in message news:4650499f (AT) newsgroups (DOT) borland.com... Quote: Juhani Suhonen schreef: Could you share it ? (my basm skills are bit rusted, but i'll try my best later today evening...) I didn't use any basm, just tweaked the Pascal code a bit based on what I saw in the CPU view. My Pascal version should be in your mailbox. Danny --- Back to top Q Correll Guest Posted: Mon May 21, 2007 10:15 pm    Post subject: Re: Any known fast hash algorithms ? danny, | done Got it. Thank you very much!!! -- Q 05/21/2007 10:15:33 XanaNews Version 1.17.5.7 [Q's salutation mod] Back to top danny heijl Guest Posted: Tue May 22, 2007 2:11 am    Post subject: Re: Any known fast hash algorithms ? Juhani Suhonen schreef: Quote: Could you please repost (my correct mail address is) juhani <dot> suhonen <at> a1netti <dot> com Ok, didn't notice the .cmo ... Danny --- Back to top Terry Guest Posted: Tue May 22, 2007 5:07 am    Post subject: Re: Any known fast hash algorithms ? Quote: It has been in use for several years now performing millions of hashses a day for me. Could I get that also ? Thank you, Terry. Back to top danny heijl Guest Posted: Tue May 22, 2007 8:11 am    Post subject: Re: Any known fast hash algorithms ? Terry schreef: Quote: Could I get that also ? done. danny --- Back to top Display posts from previous: All Posts1 Day7 Days2 Weeks1 Month3 Months6 Months1 Year Oldest FirstNewest First         BorlandTalk.com Forum Index -> Delphi Language BASM All times are GMT Page 1 of 1   Jump to: Select a forum C++ Builder Newsgroups----------------C++ BuilderC++ Builder (ActiveX)C++ Builder (Announcements)C++ Builder (Command Line Tools)C++ Builder DatabasesC++ Builder Databases (ADO)C++ Builder Databases (Desktop)C++ Builder Databases (InterBase Express)C++ Builder Databases (Multi-Tier)C++ Builder Databases (SQL Servers)C++ Builder (Graphics)C++ Builder (IDE)C++ Builder (Internet)C++ Builder (Internet Socket)C++ Builder (Internet Web)C++ Builder (Jobs)C++ Builder (Language)C++ Builder (Language C++)C++ Builder (Compatibility with MFC)C++ Builder (Native API)C++ Builder (Non-Technical)C++ Builder (Students)C++ Builder (Third Party Tools)C++ Builder (Upgrade)C++ Builder (VCL)C++ Builder (VCL Components Usage)C++ Builder (VCL Components Development)C++ Builder (VCL Usage)C++ Builder (WinAPI)C++ Builder Installation Delphi Newsgroups----------------Delphi (General)Delphi ActiveX Controls UsageDelphi ActiveX Controls DevelopmentDelphi As400Delphi DatabasesDelphi Databases (ADO)Delphi Databases (dbExpress)Delphi Databases (Desktop)Delphi Databases (InterBase Express)Delphi Databases (Multi-Tier)Delphi Databases (SQL Servers)Delphi DeploymentDelphi GraphicsDelphi IDEDelphi InternationalizationDelphi InternetDelphi Internet Isapi-WebBrokerDelphi Internet WebSnapDelphi Internet WinsockDelphi JobsDelphi Language BASMDelphi Language ObjectPascalDelphi Model Driven Architecture (General)Delphi Model Driven Architecture (Third Party)Delphi MultimediaDelphi Native APIDelphi Non-TechnicalDelphi ObjectPascalDelphi OLE AutomationDelphi OO designDelphi OpenToolsAPIDelphi Reporting-ChartingDelphi RTLDelphi StudentsDelphi TeamSourceDelphi Thirdparty ToolsDelphi Thirdparty Tools (General)Delphi Thirdparty Tools (IntraWeb)Delphi Thirdparty Tools (RaveReports)Delphi UpgradeDelphi VCLDelphi VCL ComponentsDelphi VCL Components UsingDelphi VCL Components WritingDelphi WebServices SOAPDelphi WinAPIDelphi XMLDelphi Installationcomp.lang.pascal.delphi.components.misccomp.lang.pascal.delphi.components.usagecomp.lang.pascal.delphi.components.writingcomp.lang.pascal.delphi.databasescomp.lang.pascal.delphi.misccomp.sources.delphi JBuilder Newsgroups----------------JBuilderJBuilder AnnouncementsJBuilder Applet IssuesJBuilder As400JBuilder CompilerJBuilder CORBA/RMIJBuilder DatabasesJBuilder DB SwingJBuilder DebuggerJBuilder DeploymentJBuilder DocumentationJBuilder EnterpriseJBuilder HandheldJBuilder IDEJBuilder JavaJBuilder JavaAPIJBuilder Java LanguageJBuilder Java SwingJBuilder Java BeansJBuilder Java Beans UsageJBuilder Java Beans DevelopmentJBuilder JBCLJBuilder JDataStoreJBuilder JobsJBuilder LinuxJBuilder MacintoshJBuilder & MobileSetJBuilder MultiLingual AppsJBuilder Non-TechnicalJBuilder OpenToolsJBuilder Servlets (JSP)JBuilder StudentsJBuilder Team DevelopmentJBuilder Thirdparty ToolsJBuilder UpgradeJBuilder Installation InterBase Newsgroups----------------InterBaseInterBase Bug DiscussionInterBase GeneralInterBase IBConsoleInterBase OpenSourceInterBase ReplicationInterBase SQLInterBase ThirdpartyInterBase Installation Miscellaneous Borland Newsgroups----------------AppCenterAppServerEnteraVisiBroker  You cannot post new topics in this forum You cannot reply to topics in this forum You cannot edit your posts in this forum You cannot delete your posts in this forum You cannot vote in polls in this forum Powered by phpBB © 2001, 2006 phpBB Group SEO toolkit © 2004-2006 webmedic.