RE: Question about STRINGs...

Howdy.

Thanks a lot for the info José - I'll give it a try.


-----Original Message-----
From:	José Bollo [mailto:[email protected]]
Sent:	Tue 5/31/2005 6:20 PM

To:	[email protected]
Cc:	
Subject:	Re: Question about STRINGs...
Le mardi 31 Mai 2005 08:46, Phil Malin a écrit :
> Hi there.
>
> I've been writing some network code (using my own network library I
> wrote ages ago) and have come across a bit of an annoyance (more than
> likely brought about by my own lack of knowledge).  In my code I
> currently use an array of characters as a read buffer rather than a
> STRING because when I originally wrote it I wasn't sure how STRINGs
> would handle arbitrary CHARACTERs (like nulls, etc.).  From looking at
> the STRING code it seems as though it'd be ok because it uses a
> separately defined 'count' to state the size rather than a trailing '\0'
> as in C.  Is this correct?
>
> If this is the case, what would be the best way of copying arbitrary
> data in a C array into a STRING (since a lot of the time the user will
> be wanting the result as a STRING).  The only routines in STRING are
> 'from_external' and 'from_external_copy', which seem to copy until a
> '\0' is hit (which won't be of help to me here).
>
> The easy approach is to simply create a STRING with a certain capacity
> and then loop through the buffer of read data appending each character
> at a time (which is pretty inefficient).


That approach allow you to avoid copies. 

statically
1. reserve the capacity you want: string.make(max)
2. inherit STRING_HANDLER

dynamically
3. resize the string to the wanted max buffer read: string.resize(max)
4. read using pointer: string.storage.to_external
5. resize the string on what you read: string.resize(readen)

remarks:
CAUTION you are at LOW level
the effect of resize is to give a FULLY useable STRING object but if it is 
more usefull for you to not resize then do it because it can avoid some 
unusefull operations.


> Is there any possibility to add a creation routine to STRING such as
>
>     copy_external_sequence(ptr : POINTER;size : INTEGER)
>
>
> or something so one can copy some arbitrary data pointed to by 'ptr' in
> an efficient way (by having it use bcopy/memcpy/etc.)?
>
> Thanks in advance for any pointers (pardon the pun ;-) ).
>
> Cheers.
>
> Phil.