bool McParser::readUmbrellaData() {
while (!readBuffer_.empty()) {
auto st = um_parse_header(readBuffer_.data(),
readBuffer_.length(),
&umMsgInfo_);
if (st == um_not_enough_data) {
return true;
}
if (st != um_ok) {
errorHelper(McReply(mc_res_remote_error,
"Error parsing Umbrella header"));
return false;
}
/* Three cases: */
if (readBuffer_.length() >= umMsgInfo_.message_size) {
/* 1) we already have the entire message */
if (!umMessageReady(
readBuffer_.data(),
readBuffer_.data() + umMsgInfo_.header_size,
readBuffer_)) {
readBuffer_.clear();
return false;
}
/* Re-enter the loop */
readBuffer_.trimStart(umMsgInfo_.message_size);
continue;
} else if (readBuffer_.length() >= umMsgInfo_.header_size &&
umMsgInfo_.message_size - readBuffer_.length() >
minBufferSize_) {
/* 2) we have the entire header, but body is incomplete.
Copy the partially read body into the new buffer.
TODO: this copy could be eliminated, but needs
some modification of umbrella library. */
auto partial = readBuffer_.length() - umMsgInfo_.header_size;
umBodyBuffer_ = folly::IOBuf::copyBuffer(
readBuffer_.data() + umMsgInfo_.header_size,
partial,
/* headroom= */ 0,
/* minTailroom= */ umMsgInfo_.body_size - partial);
return true;
}
/* 3) else header is incomplete */
return true;
}
return true;
}
um_status_t um_consume_no_copy(const uint8_t* header, size_t nheader,
const uint8_t* body, size_t nbody,
uint64_t* reqid_out,
mc_msg_t* msg_out) {
FBI_ASSERT(header && body && reqid_out && msg_out);
um_message_info_t info;
um_status_t header_rv = um_parse_header(header, nheader, &info);
if (header_rv != um_ok) {
return header_rv;
}
if (!(nheader == info.header_size &&
nbody == info.body_size &&
nheader + nbody == info.message_size)) {
return um_invalid_range;
}
entry_list_t elist;
entry_list_init(&elist);
/* We know that header/body won't be modified here,
but the interface is messed up */
ssize_t rv = entry_list_read_from_buf(&elist,
(char*)header, nheader,
(char*)body, nbody,
/*free_buf_when_done=*/0);
if (rv < 0 || rv != info.message_size) {
return um_message_parse_error;
}
_parse_info_t parse_info;
if (_fill_base_msg(&elist, msg_out, &parse_info) != 0) {
return um_message_parse_error;
}
/* TODO: support stats with no_copy API */
if (parse_info.stats_count > 0) {
return um_message_parse_error;
}
if (_fill_msg_strs(msg_out, &elist, body, &parse_info) != 0) {
return um_message_parse_error;
}
*reqid_out = parse_info.reqid;
return um_ok;
}
