readint16 limit ???

Mar 18, 2006 at 10:54pm

readint16 limit ???

Hi,

i’m quite new to Javascript, so please forgive etc..

can’t figure this one out:

I have this line to read a chunk from a file:

var blockVals = curFile.readint16(totPoints*4);

I know the file exists, it’s open, it is long enough, but the above
line gives me a ‘BlockVals has no properties’ error.

the funny thing is that if I replace with this:

var blockVals = curFile.readint16(totPoints);
var blockVals = curFile.readint16(totPoints);
var blockVals = curFile.readint16(totPoints);
var blockVals = curFile.readint16(totPoints);

there’s no problem, it reads everything it has to read, but in four
chunks.
I’m trying this with a chunk of 9528 bytes (4764 int16′s).

so is this some limit to what readint16 can take ? (seems unlikely ??)
or is this some limit to the length of implicitly declared arrays ?

please enlighten…someone..thanks..

ciao,

Joost.

——————————————-

Joost Rekveld
———– http://www.lumen.nu/rekveld

——————————————-

“The question of whether a computer can think
is no more interesting than the question
of whether a submarine can swim.”
(E. W. Dijkstra)

——————————————-

#24952
Mar 19, 2006 at 9:06pm

Hi folks,

i’m still a bit stuck here. This behaviours occurs with all kinds of
files I’ve found out in the meantime, and there seems to be a limit of
8k to what readint16 can handle, below that all is fine…

Where does this limit come from ? Is this a bug or some kind of buffer
with a size I can set ?
Is there another approach I should be taking to read larger chunks of
files ?

I hope somebody can explain, since I understand the ‘file’-object is
not a standard part of javascript..

thanks,

Joost.

——————————————-

Joost Rekveld
———– http://www.lumen.nu/rekveld

——————————————-

“The mystery of the world is the visible, not the invisible”
(Oscar Wilde)

——————————————-

#72841
Mar 19, 2006 at 11:50pm

On Mar 19, 2006, at 1:06 PM, Joost Rekveld wrote:

> i’m still a bit stuck here. This behaviours occurs with all kinds
> of files I’ve found out in the meantime, and there seems to be a
> limit of 8k to what readint16 can handle, below that all is fine…
>
> Where does this limit come from ? Is this a bug or some kind of
> buffer with a size I can set ?

The atom to JS conversion is limited to something like 4096 elements.
This is not settable.

> Is there another approach I should be taking to read larger chunks
> of files ?

Yes. Read in smaller chunks appending the corresponding array values
as you read them in.

-Joshua

#72842
Mar 20, 2006 at 8:48am

thanks for the clarification Joshua,
i’ll do smaller chunks, since now I know why..

thanks,

Joost.

——————————————-

Joost Rekveld
———– http://www.lumen.nu/rekveld

——————————————-

“The mystery of the world is the visible, not the invisible”
(Oscar Wilde)

——————————————-

#72843

You must be logged in to reply to this topic.