Rebol Request-Download doesn't support Big File: how to correct?
-
07-07-2019 - |
Question
download-dir: request-dir
Print ["downloading " "VStudio2008Express.iso" "..." ]
url: http://go.microsoft.com/fwlink/?LinkId=104679
file-save: to-rebol-file rejoin [download-dir "VStudio2008Express.iso"]
request-download/to url file-save
In the end whereas the progress bar has shown the download has finished:
** Script Error: Not enough memory
** Where: append
** Near: insert tail series :value
>>
So how to correct request-download as it is a mezzanine function:
func [
{Request a file download from the net. Show progress. Return none on error.}
url [url!]
/to "Specify local file target." local-file [file! none!]
/local prog lo stop data stat event-port event
][
view/new center-face lo: layout [
backeffect [gradient 1x1 water gray]
space 10x8
vh2 300 gold "Downloading File:"
vtext bold center 300 to-string url
prog: progress 300
across
btn 90 "Cancel" [stop: true]
stat: text 160x24 middle
]
stop: false
data: read-thru/to/progress/update url local-file func [total bytes] [
prog/data: bytes / (max 1 total)
stat/text: reform [bytes "bytes"]
show [prog stat]
not stop
]
unview/only lo
if not stop [data]
]
Solution
OTHER TIPS
Rebol's read functions read all the input data into memory at once and cannot be used on large datasets. You have to open a port and copy the data from it in chunks to handle large datasets.
I would think that the request-download function could be modified to use ports for both the input and output data. This thread from the Rebol Mailing List may help you:
http://www.rebol.org/ml-display-thread.r?m=rmlFQXC
You can find a fuller example on Carl's blog at http://www.rebol.com/cgi-bin/blog.r?view=0281#comments
Even using this technique there is a limit of approximately 2Gb to the size of files that can be handled in Rebol 2.