COMMAND
- memchan -initial-size len
-
creates a chunk-oriented in-memory channel and returns its handle. If
an initial size is specified the system will pre-allocate len
bytes of buffer space for the contents. This is no restriction on the
ultimate size of the channel, it will always grow as much as is
necessary to accomodate the data written into it.
The channels created here can be transfered between interpreters in
the same thread and between threads, but only as a whole. It is not
possible to use them to create a bi- or unidirectional connection
between two interpreters.
Memory channels created by memchan provide two read-only options
which can be queried via the standard fconfigure command. These
are
- -length
-
The value of this option is the number of bytes currently
stored in the queried memory channel.
- -allocated
-
The value of this option is the number of bytes currently
allocated by the queried memory channel. This number is at
least as big as the value of -length.
As the channels generated by memchan grow as necessary they are
always writable. This means that a writable fileevent-handler
will fire continuously.
The channels are also readable if they contain more than zero bytes
and the seek location is not and the end of the channel. Under these
conditions a readable fileevent-handler will fire continuously.
Note that writing to such a channel usually occurs at the end, thus
supressing readable events. This also means that users have to take
care to seek the channel to a location before the end before
trying to read data back.