9:06 p.m.
Convert an if-else chain into a switch statement. Upcoming patches
will add even more recognized reply types, at which point direct
dispatch is smarter. No semantic change; the biggest part of the diff
is code motion to consolidate the handling of error vs. unknown reply
types into a single default label.
---
generator/states-reply-structured.c | 77 +++++++++++++++--------------
1 file changed, 40 insertions(+), 37 deletions(-)
diff --git a/generator/states-reply-structured.c b/generator/states-reply-structured.c
index b209b41..2159798 100644
--- a/generator/states-reply-structured.c
+++ b/generator/states-reply-structured.c
@@ -98,32 +98,22 @@ STATE_MACHINE {
return 0;
}
- if (NBD_REPLY_TYPE_IS_ERR (type)) {
- if (length < sizeof h->sbuf.sr.payload.error.error) {
- SET_NEXT_STATE (%.DEAD);
- set_error (0, "too short length in structured reply error");
- return 0;
- }
- h->rbuf = &h->sbuf.sr.payload.error.error;
- h->rlen = sizeof h->sbuf.sr.payload.error.error;
- SET_NEXT_STATE (%RECV_ERROR);
- return 0;
- }
- else if (type == NBD_REPLY_TYPE_NONE) {
+ switch (type) {
+ case NBD_REPLY_TYPE_NONE:
if (length != 0) {
SET_NEXT_STATE (%.DEAD);
set_error (0, "invalid length in NBD_REPLY_TYPE_NONE");
- return 0;
+ break;
}
if (!(flags & NBD_REPLY_FLAG_DONE)) {
SET_NEXT_STATE (%.DEAD);
set_error (0, "NBD_REPLY_FLAG_DONE must be set in NBD_REPLY_TYPE_NONE");
- return 0;
+ break;
}
SET_NEXT_STATE (%FINISH);
- return 0;
- }
- else if (type == NBD_REPLY_TYPE_OFFSET_DATA) {
+ break;
+
+ case NBD_REPLY_TYPE_OFFSET_DATA:
/* The spec states that 0-length requests are unspecified, but
* 0-length replies are broken. Still, it's easy enough to support
* them as an extension, so we use < instead of <=.
@@ -134,56 +124,56 @@ STATE_MACHINE {
"cmd->type=%" PRIu16 ", "
"this is likely to be a bug in the server",
cmd->type);
- return 0;
+ break;
}
if (length < sizeof h->sbuf.sr.payload.offset_data) {
SET_NEXT_STATE (%.DEAD);
set_error (0, "too short length in NBD_REPLY_TYPE_OFFSET_DATA");
- return 0;
+ break;
}
h->rbuf = &h->sbuf.sr.payload.offset_data;
h->rlen = sizeof h->sbuf.sr.payload.offset_data;
SET_NEXT_STATE (%RECV_OFFSET_DATA);
- return 0;
- }
- else if (type == NBD_REPLY_TYPE_OFFSET_HOLE) {
+ break;
+
+ case NBD_REPLY_TYPE_OFFSET_HOLE:
if (cmd->type != NBD_CMD_READ) {
SET_NEXT_STATE (%.DEAD);
set_error (0, "invalid command for receiving offset-hole chunk, "
"cmd->type=%" PRIu16 ", "
"this is likely to be a bug in the server",
cmd->type);
- return 0;
+ break;
}
if (length != sizeof h->sbuf.sr.payload.offset_hole) {
SET_NEXT_STATE (%.DEAD);
set_error (0, "invalid length in NBD_REPLY_TYPE_OFFSET_HOLE");
- return 0;
+ break;
}
h->rbuf = &h->sbuf.sr.payload.offset_hole;
h->rlen = sizeof h->sbuf.sr.payload.offset_hole;
SET_NEXT_STATE (%RECV_OFFSET_HOLE);
- return 0;
- }
- else if (type == NBD_REPLY_TYPE_BLOCK_STATUS) {
+ break;
+
+ case NBD_REPLY_TYPE_BLOCK_STATUS:
if (cmd->type != NBD_CMD_BLOCK_STATUS) {
SET_NEXT_STATE (%.DEAD);
set_error (0, "invalid command for receiving block-status chunk, "
"cmd->type=%" PRIu16 ", "
"this is likely to be a bug in the server",
cmd->type);
- return 0;
+ break;
}
/* XXX We should be able to skip the bad reply in these two cases. */
if (length < 12 || ((length-4) & 7) != 0) {
SET_NEXT_STATE (%.DEAD);
set_error (0, "invalid length in NBD_REPLY_TYPE_BLOCK_STATUS");
- return 0;
+ break;
}
if (CALLBACK_IS_NULL (cmd->cb.fn.extent)) {
SET_NEXT_STATE (%.DEAD);
set_error (0, "not expecting NBD_REPLY_TYPE_BLOCK_STATUS here");
- return 0;
+ break;
}
/* We read the context ID followed by all the entries into a
* single array and deal with it at the end.
@@ -193,18 +183,31 @@ STATE_MACHINE {
if (h->bs_entries == NULL) {
SET_NEXT_STATE (%.DEAD);
set_error (errno, "malloc");
- return 0;
+ break;
}
h->rbuf = h->bs_entries;
h->rlen = length;
SET_NEXT_STATE (%RECV_BS_ENTRIES);
- return 0;
- }
- else {
- SET_NEXT_STATE (%.DEAD);
- set_error (0, "unknown structured reply type (%" PRIu16 ")",
type);
- return 0;
+ break;
+
+ default:
+ if (NBD_REPLY_TYPE_IS_ERR (type)) {
+ if (length < sizeof h->sbuf.sr.payload.error.error) {
+ SET_NEXT_STATE (%.DEAD);
+ set_error (0, "too short length in structured reply error");
+ break;
+ }
+ h->rbuf = &h->sbuf.sr.payload.error.error;
+ h->rlen = sizeof h->sbuf.sr.payload.error.error;
+ SET_NEXT_STATE (%RECV_ERROR);
+ }
+ else {
+ SET_NEXT_STATE (%.DEAD);
+ set_error (0, "unknown structured reply type (%" PRIu16 ")",
type);
+ }
+ break;
}
+ return 0;
REPLY.STRUCTURED_REPLY.RECV_ERROR:
uint32_t length, msglen;
--
2.37.1