[REBOL] Re: [BUG] in mysql-protocol 0.9.9
From: rebol-list2:seznam:cz at: 4-Aug-2003 20:42
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!
>> change line in "data reading" from:
>> b0: b1: b2: b3: int: int24: long: string: field: len: none
>> 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:)
>> 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
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
networking/add-port db :mysql-handler
mysql-make-query: func[query [string!] port handler][
;print ["make-query:" mold query]
either db/locals/stream-end? [
networking/change-handler db :handler
insert db query
insert tail mysql-queries-buffer reduce [query port :handler]
if all [db/locals/stream-end? not empty? mysql-queries-buffer][
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 #"|") #"^@"
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