Re: Need some help with Rmail/mbox

[Stefan Monnier <monnier@IRO.UMontreal.CA>]

> (1) Do decode-coding-region while specifying a multibyte
> buffer as TARGET.

> (2) Insert the contents of unibyte buffer into a multibyte
> buffer, and then perform decode-coding-region in that
> multibyte buffer.

> (3) Get a unibyte string form a unibyte buffer, and then
> decode it while specifying a multibyte buffer as TARGET.

> (4) Deocde a unibyte buffer into a mulitbyte string, and
> then insert it into a multibyte buffer.

> (Please note that using decode-coding-region directly in a
> unibyte-buffer is not reliable because if a coding system
> has post-read-converion function, that funcion (usually)
> works only in a mutlibyte buffer.)

> The efficiency is (1) > (2) > (3) > (4).

I'd have expected 3 to be more efficient than 2 since it doesn't need to
use the variable width multibyte representation of binary data.
[ I'd even expect 3 to be about as efficient as 1. ]

Is this because of the need to copy the string contents to a temp buffer
in order to run any potential pre-read-conversion function?


        Stefan