Howdy, I've had tests with both a normal hashmap (just new HashMap() used) and a synchronized wrapper (Collections.synchronizedMap(new HashMap()). I would expect the normal HashMap to be faster than both the FastHashMap and the synchronized HashMap. Is my expectation wrong?
However, here are the results: [MapTest: FastHashMap: false / Synchronized wrapper: false / Insert time: 1592 / Read time: 30] [MapTest: FastHashMap: true / Synchronized wrapper: false / Insert time: 1265 / Read time: 6] [MapTest: FastHashMap: false / Synchronized wrapper: true / Insert time: 983 / Read time: 7] [MapTest: FastHashMap: false / Synchronized wrapper: false / Insert time: 1158 / Read time: 2] [MapTest: FastHashMap: true / Synchronized wrapper: false / Insert time: 1194 / Read time: 2] [MapTest: FastHashMap: false / Synchronized wrapper: true / Insert time: 827 / Read time: 2] [MapTest: FastHashMap: false / Synchronized wrapper: false / Insert time: 990 / Read time: 2] [MapTest: FastHashMap: true / Synchronized wrapper: false / Insert time: 1006 / Read time: 2] [MapTest: FastHashMap: false / Synchronized wrapper: true / Insert time: 732 / Read time: 2] [MapTest: FastHashMap: false / Synchronized wrapper: false / Insert time: 949 / Read time: 3] [MapTest: FastHashMap: true / Synchronized wrapper: false / Insert time: 1003 / Read time: 2] [MapTest: FastHashMap: false / Synchronized wrapper: true / Insert time: 1579 / Read time: 2] [MapTest: FastHashMap: false / Synchronized wrapper: false / Insert time: 888 / Read time: 2] [MapTest: FastHashMap: true / Synchronized wrapper: false / Insert time: 1045 / Read time: 2] [MapTest: FastHashMap: false / Synchronized wrapper: true / Insert time: 793 / Read time: 2] [MapTest: FastHashMap: false / Synchronized wrapper: false / Insert time: 1151 / Read time: 2] [MapTest: FastHashMap: true / Synchronized wrapper: false / Insert time: 855 / Read time: 2] [MapTest: FastHashMap: false / Synchronized wrapper: true / Insert time: 905 / Read time: 3] [MapTest: FastHashMap: false / Synchronized wrapper: false / Insert time: 1217 / Read time: 1] [MapTest: FastHashMap: true / Synchronized wrapper: false / Insert time: 1269 / Read time: 2] [MapTest: FastHashMap: false / Synchronized wrapper: true / Insert time: 1107 / Read time: 2] [MapTest: FastHashMap: false / Synchronized wrapper: false / Insert time: 1062 / Read time: 2] [MapTest: FastHashMap: true / Synchronized wrapper: false / Insert time: 1252 / Read time: 2] [MapTest: FastHashMap: false / Synchronized wrapper: true / Insert time: 971 / Read time: 2] [MapTest: FastHashMap: false / Synchronized wrapper: false / Insert time: 1460 / Read time: 2] [MapTest: FastHashMap: true / Synchronized wrapper: false / Insert time: 1404 / Read time: 2] [MapTest: FastHashMap: false / Synchronized wrapper: true / Insert time: 1110 / Read time: 2] [MapTest: FastHashMap: false / Synchronized wrapper: false / Insert time: 1278 / Read time: 2] [MapTest: FastHashMap: true / Synchronized wrapper: false / Insert time: 1193 / Read time: 2] [MapTest: FastHashMap: false / Synchronized wrapper: true / Insert time: 1096 / Read time: 2] Yoav Shapira Millennium ChemInformatics >-----Original Message----- >From: [EMAIL PROTECTED] >[mailto:[EMAIL PROTECTED] >Sent: Tuesday, June 03, 2003 2:58 PM >To: Jakarta Commons Developers List >Subject: RE: [COLLECTIONS] FastHashMap performance > > >In your test, are you synchronizing the HashMap? FastHashMap implements >smart synchronization. It should not be compared with an unsynchronized >version of HashMap. > >P.S. In fact, it might be nice to allow doing this smart synchronization >on *any* Map. i.e. alternative to Collections.synchronizeMap(Map). > >Eric Pabst >Discover Financial Services >2500 Lake Park Blvd., 3N >West Valley City, UT 84120 >Ph: 801.902.4636 >Fax: 801.902.4123 > > > >|---------+---------------------------> >| | "Shapira, Yoav" | >| | <[EMAIL PROTECTED]| >| | i.com> | >| | | >| | 06/03/03 12:54 | >| | PM | >| | Please respond | >| | to "Jakarta | >| | Commons | >| | Developers List"| >| | | >|---------+---------------------------> > >----------------------------------------------------------------------- - >---------------------------------------| > | >| > | To: "Jakarta Commons Developers List" <commons- >[EMAIL PROTECTED]> | > | cc: >| > | Subject: RE: [COLLECTIONS] FastHashMap performance >| > >----------------------------------------------------------------------- - >---------------------------------------| > > > > > >Howdy, >I understand it's just a wrapper, and that the >reading cannot be any faster. I'm curious why the >writing is so much faster, even in the default (not fast) >mode of FastHashMap. > >Yoav Shapira >Millennium ChemInformatics > > >>-----Original Message----- >>From: Juozas Baliuka [mailto:[EMAIL PROTECTED] >>Sent: Tuesday, June 03, 2003 2:36 PM >>To: Jakarta Commons Developers List >>Subject: Re: [COLLECTIONS] FastHashMap performance >> >>FastHashMap can not be faster than HasMap in single thread just because >it >>uses HasMap to implement mappings: >> >> public Object get(Object key) { >> if (fast) { >> return (map.get(key)); >> } else { >> synchronized (map) { >> return (map.get(key)); >> } >> } >> } >> >> >>/** >> * Construct an empty map. >> */ >> public FastHashMap() { >> super(); >> this.map = new HashMap(); >> } >> >>----- Original Message ----- >>From: "Shapira, Yoav" <[EMAIL PROTECTED]> >>To: "Jakarta Commons Developers List" <[EMAIL PROTECTED]> >>Sent: Tuesday, June 03, 2003 8:00 PM >>Subject: RE: [COLLECTIONS] FastHashMap performance >> >> >>Howdy, >>Neither did I, but I just ran the attached benchmark and got surprising >>results. I hope the attachement comes through OK: if not I'll re-post >>inline. This benchmark has just one thread writing, one thread >reading, >>which I expected to be the case where FastHashMap is not as efficient >as >>HashMap. >> >>The benchmark inserts 100000 records in the map, then reads 1000 of >>those at random. I run this 10 times for each map implemention. I'm >>ignoring the first run read times as there's overhead in initializing >>the Random generator. >> >>I'm running this test on JDK 1.4.1, no special java switches, just java >>MapTest on the command line, on Solaris 8. >> >>I'm very curious to hear comments, ideas. I was expecting to have to >>write another test with multiple writing threads, but if FastHashMap is >>faster even for the simple case, why ever use the regular HashMap? >> >>The results are: >>[MapTest: Map class: java.util.HashMap / Insert time: 1616 / Read time: >>30] >>[MapTest: Map class: org.apache.commons.collections.FastHashMap / >Insert >>time: 1252 / Read time: 6] >>[MapTest: Map class: java.util.HashMap / Insert time: 958 / Read time: >>2] >>[MapTest: Map class: org.apache.commons.collections.FastHashMap / >Insert >>time: 1203 / Read time: 2] >>[MapTest: Map class: java.util.HashMap / Insert time: 820 / Read time: >>2] >>[MapTest: Map class: org.apache.commons.collections.FastHashMap / >Insert >>time: 988 / Read time: 2] >>[MapTest: Map class: java.util.HashMap / Insert time: 781 / Read time: >>2] >>[MapTest: Map class: org.apache.commons.collections.FastHashMap / >Insert >>time: 1033 / Read time: 3] >>[MapTest: Map class: java.util.HashMap / Insert time: 720 / Read time: >>2] >>[MapTest: Map class: org.apache.commons.collections.FastHashMap / >Insert >>time: 1067 / Read time: 2] >>[MapTest: Map class: java.util.HashMap / Insert time: 1454 / Read time: >>2] >>[MapTest: Map class: org.apache.commons.collections.FastHashMap / >Insert >>time: 1267 / Read time: 2] >>[MapTest: Map class: java.util.HashMap / Insert time: 1534 / Read time: >>2] >>[MapTest: Map class: org.apache.commons.collections.FastHashMap / >Insert >>time: 862 / Read time: 2] >>[MapTest: Map class: java.util.HashMap / Insert time: 1433 / Read time: >>2] >>[MapTest: Map class: org.apache.commons.collections.FastHashMap / >Insert >>time: 844 / Read time: 2] >>[MapTest: Map class: java.util.HashMap / Insert time: 1578 / Read time: >>2] >>[MapTest: Map class: org.apache.commons.collections.FastHashMap / >Insert >>time: 1488 / Read time: 2] >>[MapTest: Map class: java.util.HashMap / Insert time: 1450 / Read time: >>2] >>[MapTest: Map class: org.apache.commons.collections.FastHashMap / >Insert >>time: 859 / Read time: 2] >> >>Yoav Shapira >>Millennium ChemInformatics >> >> >>>-----Original Message----- >>>From: Juozas Baliuka [mailto:[EMAIL PROTECTED] >>>Sent: Tuesday, June 03, 2003 1:53 PM >>>To: Jakarta Commons Developers List >>>Subject: Re: [COLLECTIONS] FastHashMap performance >>> >>>I do not think it is faster than java.util.HashMap, it is just pseudo >>>thread >>>safe wrapper. >>> >>>----- Original Message ----- >>>From: "Shapira, Yoav" <[EMAIL PROTECTED]> >>>To: <[EMAIL PROTECTED]> >>>Sent: Tuesday, June 03, 2003 7:17 PM >>>Subject: [COLLECTIONS] FastHashMap performance >>> >>> >>> >>>Howdy, >>>Has anyone benchmarked the performance of the FastHashMap and how it >>>compares to the java.util.HashMap implementation? If so, are the >>>benchmarks available online somewhere? >>> >>>I don't doubt its quality nor its performance, just curious... Thanks, >>> >>>Yoav Shapira >>>Millennium ChemInformatics >>> >>> >>> >>> >>> >>>This e-mail, including any attachments, is a confidential business >>>communication, and may contain information that is confidential, >>>proprietary >>>and/or privileged. This e-mail is intended only for the individual(s) >>to >>>whom it is addressed, and may not be saved, copied, printed, disclosed >>or >>>used by anyone else. If you are not the(an) intended recipient, >please >>>immediately delete this e-mail from your computer system and notify >the >>>sender. Thank you. >>> >>> >>>--------------------------------------------------------------------- >>>To unsubscribe, e-mail: [EMAIL PROTECTED] >>>For additional commands, e-mail: [EMAIL PROTECTED] >>> >>> >>> >>>--------------------------------------------------------------------- >>>To unsubscribe, e-mail: [EMAIL PROTECTED] >>>For additional commands, e-mail: [EMAIL PROTECTED] >> >> >> >> >>This e-mail, including any attachments, is a confidential business >>communication, and may contain information that is confidential, >>proprietary >>and/or privileged. This e-mail is intended only for the individual(s) >to >>whom it is addressed, and may not be saved, copied, printed, disclosed >or >>used by anyone else. If you are not the(an) intended recipient, please >>immediately delete this e-mail from your computer system and notify the >>sender. Thank you. >> >> >> >> >> >>---------------------------------------------------------------------- - >---- >>- >>---- >> >> >>> --------------------------------------------------------------------- >>> To unsubscribe, e-mail: [EMAIL PROTECTED] >>> For additional commands, e-mail: [EMAIL PROTECTED] >> >> >>--------------------------------------------------------------------- >>To unsubscribe, e-mail: [EMAIL PROTECTED] >>For additional commands, e-mail: [EMAIL PROTECTED] > > > > >This e-mail, including any attachments, is a confidential business >communication, and may contain information that is confidential, >proprietary and/or privileged. This e-mail is intended only for the >individual(s) to whom it is addressed, and may not be saved, copied, >printed, disclosed or used by anyone else. If you are not the(an) intended >recipient, please immediately delete this e-mail from your computer system >and notify the sender. Thank you. > > >--------------------------------------------------------------------- >To unsubscribe, e-mail: [EMAIL PROTECTED] >For additional commands, e-mail: [EMAIL PROTECTED] > > > > > > > >--------------------------------------------------------------------- >To unsubscribe, e-mail: [EMAIL PROTECTED] >For additional commands, e-mail: [EMAIL PROTECTED] This e-mail, including any attachments, is a confidential business communication, and may contain information that is confidential, proprietary and/or privileged. This e-mail is intended only for the individual(s) to whom it is addressed, and may not be saved, copied, printed, disclosed or used by anyone else. If you are not the(an) intended recipient, please immediately delete this e-mail from your computer system and notify the sender. Thank you. --------------------------------------------------------------------- To unsubscribe, e-mail: [EMAIL PROTECTED] For additional commands, e-mail: [EMAIL PROTECTED]
