Aduke.1449
net.news
utzoo!decvax!duke!swd
Fri Dec  4 10:09:07 1981
Re: sdcarl.108: BUFLEN
Why not malloc a buffer?

When the 'A' version of news was designed, we attempted to write
clean, portable, small code.  We also attempted to put in
sufficiently many error checks to prevent nasty core dump
messages.

Whether or not we succeded, our goals lead us to reject the use
of malloc(3).  There are several reasons.  The first is speed:
the sbrk system call can take a long time.  Also, for small
systems, being able to say 'size news' and know how large the
program *really* is is important.

I suspect that the code required to guess at the proper size of
buffer, and the when it finds that the line it just tried to read
(and only got the begining of) won't fit in its buffer, allocate
a bigger buffer (how big?), copy the old one and read some more,
would be bigger than just having larger static buffers, and a lot
slower.  Also, what happens when malloc fails for lack of memory?
It can be very messy to clean up and recover gracefully,
particularly since your stack may choose that precise moment to
need to be expanded (oops!).

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