qemu-char: Saner naming of memchar stuff & doc fixes

New device, has never been released, so we can still improve things
without worrying about compatibility.

Naming is a mess.  The code calls the device driver CirMemCharDriver,
the public API calls it "memory", "memchardev", or "memchar", and the
special commands are named like "memchar-FOO".  "memory" is a
particularly unfortunate choice, because there's another character
device driver called MemoryDriver.  Moreover, the device's distinctive
property is that it's a ring buffer, not that's in memory.  Therefore:

* Rename CirMemCharDriver to RingBufCharDriver, and call the thing a
  "ringbuf" in the API.

* Rename QMP and HMP commands from memchar-FOO to ringbuf-FOO.

* Rename device parameter from maxcapacity to size (simple words are
  good for you).

* Clearly mark the parameter as optional in documentation.

* Fix error reporting so that chardev-add reports to current monitor,
  not stderr.

* Replace cirmem in C identifiers by ringbuf.

* Rework documentation.  Document the impact of our crappy UTF-8
  handling on reading.

* QMP examples that even work.

I could split this up into multiple commits, but they'd change the
same documentation lines multiple times.  Not worth it.

Signed-off-by: Markus Armbruster <armbru@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>

1 files changed, 4 insertions, 4 deletions

diff --git a/hmp.c b/hmp.c
index f6bb7675ba..cbd572753b 100644
--- a/hmp.c
+++ b/hmp.c
@@ -662,25 +662,25 @@ void hmp_pmemsave(Monitor *mon, const QDict *qdict)
     hmp_handle_error(mon, &errp);
 }
 
-void hmp_memchar_write(Monitor *mon, const QDict *qdict)
+void hmp_ringbuf_write(Monitor *mon, const QDict *qdict)
 {
     const char *chardev = qdict_get_str(qdict, "device");
     const char *data = qdict_get_str(qdict, "data");
     Error *errp = NULL;
 
-    qmp_memchar_write(chardev, data, false, 0, &errp);
+    qmp_ringbuf_write(chardev, data, false, 0, &errp);
 
     hmp_handle_error(mon, &errp);
 }
 
-void hmp_memchar_read(Monitor *mon, const QDict *qdict)
+void hmp_ringbuf_read(Monitor *mon, const QDict *qdict)
 {
     uint32_t size = qdict_get_int(qdict, "size");
     const char *chardev = qdict_get_str(qdict, "device");
     char *data;
     Error *errp = NULL;
 
-    data = qmp_memchar_read(chardev, size, false, 0, &errp);
+    data = qmp_ringbuf_read(chardev, size, false, 0, &errp);
     if (errp) {
         monitor_printf(mon, "%s\n", error_get_pretty(errp));
         error_free(errp);