fixes #4 Statistics support

This introduces new public APIs for obtaining statistics,
and adds some generic stats for dialers, listeners, pipes, and
sockets.  Also added are stats for inproc and pairv1 protocol.

The other protocols and transports will have stats added
incrementally as time goes on.

A simple test program, and man pages are provided for this.
Start by looking at nng_stat(5).

Statistics does have some impact, and they can be disabled by
using the advanced NNG_ENABLE_STATS (setting it to OFF, it's
ON by default) if you need to build a minimized configuration.

1 files changed, 0 insertions, 68 deletions

diff --git a/src/nng.c b/src/nng.c
index 64968cae..f98727ce 100644
--- a/src/nng.c
+++ b/src/nng.c
@@ -1594,74 +1594,6 @@ nng_aio_begin(nng_aio *aio)
 	return (true);
 }
 
-#if 0
-int
-nng_snapshot_create(nng_socket sock, nng_snapshot **snapp)
-{
-	// Stats TBD.
-	NNI_ARG_UNUSED(sock)
-	NNI_ARG_UNUSED(snapp)
-	return (NNG_ENOTSUP);
-}
-
-void
-nng_snapshot_free(nng_snapshot *snap)
-{
-	NNI_ARG_UNUSED(snap)
-	// Stats TBD.
-}
-
-int
-nng_snapshot_update(nng_snapshot *snap)
-{
-	NNI_ARG_UNUSED(snap)
-	// Stats TBD.
-	return (NNG_ENOTSUP);
-}
-
-int
-nng_snapshot_next(nng_snapshot *snap, nng_stat **statp)
-{
-	NNI_ARG_UNUSED(snap)
-	NNI_ARG_UNUSED(statp)
-	// Stats TBD.
-	*statp = NULL;
-	return (NNG_ENOTSUP);
-}
-
-const char *
-nng_stat_name(nng_stat *stat)
-{
-	NNI_ARG_UNUSED(stat)
-	// Stats TBD.
-	return (NULL);
-}
-
-int
-nng_stat_type(nng_stat *stat)
-{
-	NNI_ARG_UNUSED(stat)
-	// Stats TBD.
-	return (0);
-}
-
-int
-nng_stat_unit(nng_stat *stat)
-{
-	NNI_ARG_UNUSED(stat)
-    // Stats TBD.
-    return (0);
-}
-
-int64_t
-nng_stat_value(nng_stat *stat)
-{
-	NNI_ARG_UNUSED(stat)
-	// Stats TBD.
-	return (0);
-}
-#endif
-
 int
 nng_url_parse(nng_url **result, const char *ustr)
 {