Re: [libvirt] [PATCH v2] Add systemd journal support

From: "Daniel P. Berrange" <berrange(a)redhat.com&gt; Add support for logging to the systemd journal, using its simple client library. The benefit over syslog is that it accepts structured log data, so the journald can store individual items like code file/line/func separately from the string message. Tools which require structured log data can then query the journal to extract exactly what they desire without resorting to string parsing While systemd provides a simple client library for logging, it is more convenient for libvirt to directly write its own client code. This lets us build up the iovec's on the stack, avoiding the need to alloc memory when writing log messages.

+ + if (strchr(rawstr, '\n')) { + uint64_t nstr; + /* If 'str' containes a newline, then we must + * encode the string length, since we can't + * rely on the newline for the field separator + */ + IOVEC_SET_STRING(iov[niov++], "MESSAGE\n"); + nstr = htole64(strlen(rawstr));

+ if ((buffd = mkostemp(path, O_CLOEXEC|O_RDWR)) < 0) + return;