Changeset a22c979

Timestamp:

10/26/04 14:56:57 (16 years ago)

Author:

Daniel Lawson <dlawson@…>

Branches:

4.0.1-hotfixes, cachetimestamps, develop, dpdk-ndag, etsilive, getfragoff, help, libtrace4, master, ndag_format, pfring, rc-4.0.1, rc-4.0.2, rc-4.0.3, rc-4.0.4, ringdecrementfix, ringperformance, ringtimestampfixes

Children:

678048a

Parents:

59c31da

Message:

improving dag reads

Location:

lib

Files:

• libtrace.h (modified) (1 diff)
• trace.c (modified) (8 diffs)

lib/libtrace.h

@@ -82 +82 @@
 struct libtrace_packet_t {
         struct libtrace_t *trace;
-        char buffer[LIBTRACE_PACKET_BUFSIZE];
+        void *buffer;
+        //char buffer[LIBTRACE_PACKET_BUFSIZE];
         size_t size;
         uint8_t status;

lib/trace.c

@@ -131 +131 @@
         } input;
         struct fifo_t *fifo;   
-        void *buf; 
+        struct {
+                void *buf; 
+                unsigned bottom;
+                unsigned top;
+                unsigned diff;
+                unsigned curr;
+                unsigned offset;
+        } dag;
         struct {
                 void *buffer;
@@ -405 +412 @@
                                                 exit(0);
                                         }
-                                        if((libtrace->buf = dag_mmap(libtrace->input.fd)) == MAP_FAILED) {
+                                        if((libtrace->dag.buf = dag_mmap(libtrace->input.fd)) == MAP_FAILED) {
                                                 fprintf(stderr,"Cannot mmap DAG %s: %m\n", libtrace->conn_info.path,errno);
                                                 exit(0);
@@ -448 +455 @@
 static int trace_read(struct libtrace_t *libtrace, void *buffer, size_t len) {
         int numbytes;
-        static unsigned bottom = 0, top, diff, curr = 0, scan;
         static short lctr = 0;
         struct dag_record_t *recptr = 0;
@@ -480 +486 @@
                                         case DAG:
                                                 
-                                                top = dag_offset(libtrace->input.fd,
-                                                                &bottom,
+                                                libtrace->dag.top = dag_offset(
+                                                                libtrace->input.fd,
+                                                                &(libtrace->dag.bottom),
                                                                 0);
-                                                diff = top - bottom;
+                                                libtrace->dag.diff = libtrace->dag.top -
+                                                        libtrace->dag.bottom;
                                                 
                                                 //recptr = (dag_record_t *) ((void *)libtrace->buf + (bottom + curr));
@@ -489 +497 @@
 
                                                 
-                                                memcpy(buffer,(void *)(libtrace->buf + (bottom + curr)),diff);
+                                                //memcpy(buffer,(void *)(libtrace->buf + (bottom + curr)),diff);
                                                 
                                                 //buffer=libtrace->buf + (bottom + curr);
 
-                                                numbytes=diff;
-                                                bottom=top;
+                                                numbytes=libtrace->dag.diff;
+                                                libtrace->dag.bottom = libtrace->dag.top;
+                                                libtrace->dag.offset = 0;
                                                 
                                                 break;
@@ -532 +541 @@
         char buf[RP_BUFSIZE];
         struct pcap_pkthdr pcaphdr;
+        dag_record_t *erfptr;
         const u_char *pcappkt;
         int read_required = 0;
@@ -541 +551 @@
         assert(libtrace);
         assert(packet);
+        if(packet->buffer == 0) {
+                packet->buffer = malloc(LIBTRACE_PACKET_BUFSIZE);
+        }
 
         //bzero(buffer,len);
@@ -589 +602 @@
                 return sizeof(dag_record_t) + numbytes;
         }
-        
+
+        if (libtrace->format == DAG) {
+                // we can do some zero-copy stuff here
+                while(1) {
+                        if (libtrace->dag.diff == 0) {
+                                if ((numbytes = trace_read(libtrace,buf,RP_BUFSIZE)) <= 0) 
+                                        return numbytes;
+                        }
+                        // DAG always gives us whole packets.
+
+                        erfptr = (dag_record_t *) (libtrace->dag.buf + libtrace->dag.offset);
+                        size = ntohs(erfptr->rlen);
+
+                        assert( (size - sizeof(dag_record_t)) < LIBTRACE_PACKET_BUFSIZE);
+
+                        packet->buffer = (void *)erfptr;
+                        packet->size = size;
+                        libtrace->dag.offset += size;
+                        libtrace->dag.diff -= size;
+
+                        return (size);
+                        
+                }
+        }
         do {
                 if (fifo_out_available(libtrace->fifo) == 0 || read_required) {