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| author | Rainer Gerhards <rgerhards@adiscon.com> | 2008-10-07 10:28:44 +0200 |
|---|---|---|
| committer | Rainer Gerhards <rgerhards@adiscon.com> | 2008-10-07 10:28:44 +0200 |
| commit | 7b3c05da9f126063384c80e9dd6fd5b2ae610074 (patch) | |
| tree | da860f2015682c2bcf97ddbf6b9c27c359b58181 | |
| parent | 65f74a712b111f946faaddd0583a6c7b22bd062f (diff) | |
| download | rsyslog-7b3c05da9f126063384c80e9dd6fd5b2ae610074.tar.gz rsyslog-7b3c05da9f126063384c80e9dd6fd5b2ae610074.tar.xz rsyslog-7b3c05da9f126063384c80e9dd6fd5b2ae610074.zip | |
simple (yet efficient) name caching added to imudp
| -rw-r--r-- | plugins/imudp/imudp.c | 20 |
1 files changed, 18 insertions, 2 deletions
diff --git a/plugins/imudp/imudp.c b/plugins/imudp/imudp.c index 1865d777..d13314e8 100644 --- a/plugins/imudp/imudp.c +++ b/plugins/imudp/imudp.c @@ -133,6 +133,15 @@ finalize_it: /* This function is called to gather input. * Note that udpLstnSocks must be non-NULL because otherwise we would not have * indicated that we want to run (or we have a programming error ;)). -- rgerhards, 2008-10-02 + * rgerhards, 2008-10-07: I have implemented a very simple, yet in most cases probably + * highly efficient "name caching". Before querying a name, I now check if the name to be + * queried is the same as the one queried in the last message processed. If that is the + * case, we can simple re-use the previous value. This algorithm works quite well with + * few sender, especially if they emit messages in bursts. The more sender and the + * more intermixed messages arrive, the less this algorithm works, but the overhead + * is so minimal (a simple memory compare and move) that this does not hurt. Even + * with a real name lookup cache, this optimization here is useful as it is quicker + * than even a cache lookup). */ BEGINrunInput int maxfds; @@ -140,6 +149,7 @@ BEGINrunInput int i; fd_set readfds; struct sockaddr_storage frominet; + struct sockaddr_storage frominetPrev; socklen_t socklen; uchar fromHost[NI_MAXHOST]; uchar fromHostIP[NI_MAXHOST]; @@ -148,6 +158,10 @@ BEGINrunInput struct syslogTime stTime; int iNbrTimeUsed; CODESTARTrunInput + /* start "name caching" algo by making sure the previous system indicator + * is invalidated. + */ + memset(&frominetPrev, 0, sizeof(frominetPrev)); /* this is an endless loop - it is terminated when the thread is * signalled to do so. This, however, is handled by the framework, * right into the sleep below. @@ -184,7 +198,7 @@ CODESTARTrunInput for (i = 0; nfds && i < *udpLstnSocks; i++) { if (FD_ISSET(udpLstnSocks[i+1], &readfds)) { - socklen = sizeof(frominet); + socklen = sizeof(frominet); iNbrTimeUsed = 0; do { /* we now try to read from the file descriptor until there @@ -199,7 +213,9 @@ CODESTARTrunInput l = recvfrom(udpLstnSocks[i+1], (char*) pRcvBuf, iMaxLine, 0, (struct sockaddr *)&frominet, &socklen); if(l > 0) { - if(net.cvthname(&frominet, fromHost, fromHostFQDN, fromHostIP) == RS_RET_OK) { + if(memcmp(&frominet, &frominetPrev, socklen) == 0 || + net.cvthname(&frominet, fromHost, fromHostFQDN, fromHostIP) == RS_RET_OK) { + memcpy(&frominetPrev, &frominet, socklen); dbgprintf("Message from inetd socket: #%d, host: %s\n", udpLstnSocks[i+1], fromHost); /* Here we check if a host is permitted to send us |