Re: [libvirt] [PATCH 02/10] Provide a simple object for encoding/decoding RPC messages

On Thu, Jun 23, 2011 at 04:19:37PM -0600, Eric Blake wrote: > On 06/22/2011 09:33 AM, Daniel P. Berrange wrote: > > This provides a new struct that contains a buffer for the RPC > > message header+payload, as well as a decoded copy of the message > > header. There is an API for applying a XDR encoding & decoding > > of the message headers and payloads. There are also APIs for > > maintaining a simple FIFO queue of message instances. > > > > Expected usage scenarios are: > > > > To send a message > > > > msg = virNetMessageNew() > > > > ...fill in msg->header fields.. > > virNetMessageEncodeHeader(msg) > > ...loook at msg->header fields to determine payload filter > > virNetMessageEncodePayload(msg, xdrfilter, data) > > ...send msg->bufferLength worth of data from buffer > > > > To receive a message > > > > msg = virNetMessageNew() > > ...read VIR_NET_MESSAGE_LEN_MAX of data into buffer > > virNetMessageDecodeLength(msg) > > ...read msg->bufferLength-msg->bufferOffset of data into buffer > > virNetMessageDecodeHeader(msg) > > ...look at msg->header fields to determine payload filter > > virNetMessageDecodePayload(msg, xdrfilter, data) > > ...run payload processor > [...] > > +void virNetMessageSaveError(virNetMessageErrorPtr rerr) > > +{ > > + /* This func may be called several times & the first > > + * error is the one we want because we don't want > > + * cleanup code overwriting the first one. > > + */ > > + if (rerr->code != VIR_ERR_OK) > > + return; > > + > > + virErrorPtr verr = virGetLastError(); > > + if (verr) { > > + rerr->code = verr->code; > > + rerr->domain = verr->domain; > > + rerr->message = verr->message ? malloc(sizeof(char*)) : NULL; > > Should we really be using raw malloc here, or is it any better to use > VIR_ALLOC? (Several times in this function). I would rather use VIR_ALLOC everywhere if possible too,