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[REBOL] Re: [BUG] in mysql-protocol 0.9.9

From: rebol-list2:seznam:cz at: 4-Aug-2003 20:42

Hello dockimbel, Tuesday, July 29, 2003, 2:58:23 PM, you wrote: dff> Hi rebOldes, dff> Selon rebOldes <[rebol-list2--seznam--cz]>:
>> Hello doc, >> just want to tell you that you are using variable 'byte in the global >> context in your mysql-protocol.r version 0.9.9! >> >> FIX: >> change line in "data reading" from: >> b0: b1: b2: b3: int: int24: long: string: field: len: none >> >> to: >> b0: b1: b2: b3: int: int24: byte: long: string: field: len: none >>
dff> I would hardly call that a bug and I don't think it deserves a [BUG] banner, dff> but anyway, thanks for the report. I guess you had a hard time finding the dff> guilty source code. ;-) I've found it by accident, because as you can see I'm trying to use your protocol in async mode and variable 'byte' is not so rare to let it be as a global one. Maybe it would be good to have some utility which would be able to show how many new global variables some rebol code creates:)
>> PS: >> I'm now experimenting with running the protocol as an asyn.port so
dff> Good idea !
>> I would like to now what's the best way how to deal with the data. >> IS it better to process only one row result in time when port's >> awake or is it better to process for example 10 or more rows at
dff> It depends on the level of granularity you want to achieve. If you want to dff> multiplex several I/O tasks you'll have better results with small processing in dff> the awake handler. The MySQL driver engine was designed to read and process dff> logical data packets (my pgsql driver works on physical (tcp) packets with dff> greater performance), so you have to let it, at least, decode a complete row. I dff> would do only one row by awake events. The best way would be te recode the dff> driver to make it async by design. It's too difficult to do the re-coding by myself. I have quite a good results with copy/part 10 rows of results per 'awake' if there is about hounders of results and it seems to be ok (all these result are send as a response to more then one user.
>> this time? And if there is any support in the handler how to detect >> if the port is still busy (so I should not send any other commands >> to the db port since all data from previous sql command are >> processed)?
dff> Yes, port/local/stream-end?. If 'false, then the driver is expecting data to dff> come. You can cancel a pending command by reading at low-level all incoming dff> data and trashing it. See 'flush-pending-data function. Yes, that's whot I found by myself but that's ok with SELECTs but I would like to ask you how safe it would be with the INSERT or UPDATE sql commands which seems not to produce any responce (I mean if I would send these commands too quickly). I use something like that in my project where I'm using your protocol in 'async' mode and it's working without problems: db: open mysql://root:[root--127--0--0--1]/oldes mysql-queries-buffer: make block! 10 ;["SQL-query" target-port :handler] mysql-handler: func[port /local records][ probe records: copy/part port 10 mysql-next-query? ] networking/add-port db :mysql-handler mysql-make-query: func[query [string!] port handler][ ;print ["make-query:" mold query] either db/locals/stream-end? [ db/user-data: port networking/change-handler db :handler insert db query ][ insert tail mysql-queries-buffer reduce [query port :handler] ] ] mysql-next-query?: func[][ if all [db/locals/stream-end? not empty? mysql-queries-buffer][ db/user-data: mysql-queries-buffer/2 networking/change-handler db third mysql-queries-buffer insert db mysql-queries-buffer/1 remove/part mysql-queries-buffer 3 ] ] ;------- then I use somethink like that to make a query: mysql-make-query rejoin [ "INSERT INTO mapa_krizovatky_brno VALUES (NULL," m/x "," m/y ");" ] none none mysql-make-query rejoin [ "SELECT * FROM mapa_krizovatky_brno WHERE id=LAST_INSERT_ID();" ] port func[port /local row][ probe row: first first port ;there is no need to copy more then one row insert row "cr" insert db/user-data join (rejoin-with row #"|") #"^@" row: none mysql-next-query? ] I'm using only one mysql connection so it should be safe, but anyway is there some way how to get LAST_INSERT_ID directly? How is working for example working mysql_insert_id() function in PHP? Is it using some internal 'select' call to MySQL or is this value available from some response? -- Best regards, rebOldes mailto:[oliva--david--seznam--cz]