[REBOL] Re: mysql-protocol
From: tim:johnsons-web at: 7-Mar-2004 16:51
* Hallvard Ystad <[hallvard--ystad--oops-as--no]> [040307 15:20]:
> Hi,
>
> This is a late reply to a message from june last year.
>
> Dixit Tim Johnson (16.54 26.06.2003):
> >Hello Rebols:
> > DocKimbel and I had an OT exchange of emails early
> >this year in which I posed the the following:
> >That it would be convenient at times for me to have
> >the selection set from a query returned as a 'flat'
> >block.
> >
> >DocKimbel made the following code suggestions:
> >
> >Add 'flat' to locals-class. setting as either 'true
> >or 'false.
> >
> >in 'convert-types change the following line
> >if not empty? convert-body [foreach row rows :convert-body]
> >;to
> > if not empty? convert-body [
> > either p/locals/flat? [
> > row: rows
> > forskip row length? cols :convert-body
> > ][foreach row rows :convert-body]
> > ]
> >After implementing this - if memory serves me well -
> >DocKimbel indicated that he had observed less memory fragmentation
> >in comparison of the two methods.
>
> Why change in 'convert-types? Couldn't one just as well change these lines in 'read-rows:
> row: make block! cols
> parse/all/case row-data [any [read-field (append row field)]]
> append/only rows row
> to
> either port/locals/flat? [
> parse/all/case row-data [any [read-field (append rows field)]]
> ] [
> row: make block! cols
> parse/all/case row-data [any [read-field (append row field)]]
> append/only rows row
> ]
> ? I'm ignorant. Please tell me what way is the best.
<Grin>I'm sorry, but I can't. I'm currently using version 0.9.9
And below are the changes I have made:
; ======================================================================================================
locals-class: make object! [
; original words here ...
flat?: true ; add by Tim Johnson
]
; ======================================================================================================
convert-types: func [p [port!] rows [block!] /local row i
convert-body action cols col conv-func tmp
][
cols: p/locals/columns
convert-body: make block! 1
action: [if tmp: sys-pick row (i)]
foreach col cols [
i: index? find cols col
if 'none <> conv-func: select p/locals/conv-list col/type [
append convert-body append/only compose action head
sys-insert at compose [change at row (i) :tmp] 5 conv-func
]
]
;if not empty? convert-body [foreach row rows :convert-body] ; replaced below by Tim
Johnson
; Begin Replacement by Tim Johnson
if not empty? convert-body [ ; this and rest of function changed by Tim Johnson
either p/locals/flat? [
row: rows
forskip row length? cols :convert-body
][foreach row rows :convert-body]
]
; End Replacement by Tim Johnson
]
; ======================================================================================================
read-rows: func [port [port!] /part n [integer!]
/local row-data row rows cols count
][
; rows: make block! max any [n 0] port/locals/rows ; replaced by Tim Johnson
; cols: length? port/locals/columns ; replaced by Tim Johnson
; Begin Replacement by Tim Johnson
row-count: max any [n 0] port/locals/rows
cols: length? port/locals/columns
rows: make block! either port/locals/flat? [row-count * cols][row-count]
; End Replacement
count: 0
forever [
row-data: read-packet-via port
if empty? row-data [return []] ; empty set
row: make block! cols
parse/all/case row-data [any [read-field (append row field)]]
; append/only rows row ; this line replaced by line below: Tim Johnson
either port/locals/flat? [append rows row][append/only rows row]
if port/locals/stream-end? or all [part n = count: count + 1][break] ; end of stream
or rows # reached
]
if port/locals/auto-conv? [convert-types port rows]
recycle ; lot of garbage to recycle here ! :)
rows
]
--
Tim Johnson <[tim--johnsons-web--com]>
http://www.alaska-internet-solutions.com
