From 0545a7e105633763507c24cc45ac03942fb271b3 Mon Sep 17 00:00:00 2001
From: Ludovic Pouzenc <ludovic@pouzenc.fr>
Date: Sat, 2 Jul 2016 20:31:40 +0200
Subject: dgrambuf: full scatter/gather, no ringbuffer. Dummy data to check
 some code paths.

---
 mcastseed/src/mcastleech.c | 85 ++++++++++++++--------------------------------
 1 file changed, 26 insertions(+), 59 deletions(-)

(limited to 'mcastseed/src/mcastleech.c')

diff --git a/mcastseed/src/mcastleech.c b/mcastseed/src/mcastleech.c
index c832489..9315992 100644
--- a/mcastseed/src/mcastleech.c
+++ b/mcastseed/src/mcastleech.c
@@ -17,6 +17,7 @@
 #define MTU 1500
 #define MULTICAST_RECV_BUF (MTU-20-8)
 #define MULTICAST_SO_RCVBUF 425984
+#define DGRAM_HEADER_SIZE 8
 #define DEFAULT_MCAST_IP_STR "ff02::114"
 #define DEFAULT_PORT_STR "9000"
 
@@ -48,7 +49,7 @@ const char * const state_str[] = {
 void die(char* msg);
 void usage(char *msg);
 void arg_parse(int argc, char* argv[]);
-size_t get_available_mem();
+int get_available_mem_kb();
 void dgrambuf_init();
 uint32_t validate_data_dgram(unsigned int nread, void *recvbuf);
 void ack(uint32_t seq);
@@ -175,39 +176,7 @@ int wait_start_and_start_job() {
 
 
 int receive_data() {
-	/*
-	ssize_t nread;
-	uint32_t seq;
-	uint16_t datalen;
-
-	// Wait for a "data" datagram from the server
-	nread = recvfrom(mcast_sock, recvbuf, MULTICAST_RECV_BUF, 0, NULL, 0);
- 	if (nread < 0 ) {	
-		perror("recvfrom() failed");
-		return -1;	
-	}
-	if ( nread >= 10 && strncmp("data", recvbuf, 4) == 0 ) {
-		seq = ntohl( *( (uint32_t *) recvbuf+1 ) );
-		datalen = ntohs( *( (uint16_t *) recvbuf+4 ) );
-		if ( nread == (10 + datalen) ) {
-			ack(seq);
-			dgrambuf_memcpy_into(dgrambuf, recvbuf+10, datalen);
-		} else {
-			fprintf(stderr, "Short or inconsistent data #%u packet : nread==%zi, (10 + datalen)==%i\n", seq, nread, (10 + datalen));
-		}
-	}
-
-	return 1;
-	*/
-
-	unsigned int count;
-
-	count = dgrambuf_recvmmsg(dgrambuf, mcast_sock);
-	if (count < 0) {
-		return -1;
-	}
-
-	return 0;
+	return dgrambuf_recvmmsg(dgrambuf, mcast_sock);
 }
 
 
@@ -217,6 +186,8 @@ void ack(uint32_t seq) {
 
 
 int finalize_job() {
+	//XXX Dummy test
+	dgrambuf_write(dgrambuf, 2);
 	return 0;	
 }
 int is_there_more_job() {
@@ -252,26 +223,22 @@ void arg_parse(int argc, char* argv[]) {
 	mcast_ip = (argc >= 3)?argv[2]:DEFAULT_MCAST_IP_STR;
 }
 
-size_t get_available_mem() {
+int get_available_mem_kb() {
 	char key[64];
-	int value;
-	int found=0;
-	unsigned long int mem_avail;
+	int res, value, found=0;
 	FILE * fh = fopen("/proc/meminfo", "r");
 	if ( fh ) {
 		while (!found && !feof(fh)) {
-			fscanf(fh, "%63s %i kB\n", key, &value);
+			res = fscanf(fh, "%63s %i kB\n", key, &value);
+			if ( res < 0 )
+				break;
 			found = ( strncmp("MemAvailable:", key, 12) == 0 );
 		}
+		fclose(fh);
 	}
 
-	if ( found ) {
-		mem_avail = value * 1024;
-		if ( mem_avail > (size_t)-1 ) {
-			return -1;
-		} else {
-			return mem_avail;
-		}
+	if ( found && value > 0 ) {
+		return value;
 	}
 
 	return 0;
@@ -280,34 +247,34 @@ size_t get_available_mem() {
 void dgrambuf_init() {
 	/* Guess dgrambuf size from global free memory */
 	size_t dgram_count;
-	size_t avail_mem = get_available_mem();
+	int avail_mem = get_available_mem_kb();
+
 	if ( avail_mem < MULTICAST_SO_RCVBUF ) {
 		dgram_count = MULTICAST_SO_RCVBUF / MULTICAST_RECV_BUF;
 	} else {
-		dgram_count = avail_mem / MULTICAST_RECV_BUF / 2;
+		dgram_count = avail_mem / MULTICAST_RECV_BUF / 2 * 1024;
 	}
+	//XXX Dummy
+	dgram_count = 3;
+	fprintf(stderr, "avail_mem == %i kb, dgram_count == %zi\n", avail_mem, dgram_count);
 
 	/* Allocate dgrambuf */
-	dgrambuf = dgrambuf_new(dgram_count, MULTICAST_RECV_BUF);
+	dgrambuf = dgrambuf_new(dgram_count, MULTICAST_RECV_BUF, DGRAM_HEADER_SIZE);
 	if ( dgrambuf == NULL ) {
 		perror("dgrambuf_new/malloc");
 		exit(EXIT_FAILURE);
 	} 
 
-	printf("dgrambuf_free_count() => %zi\n", dgrambuf_free_count(dgrambuf));
+	//printf("dgrambuf_free_count() => %zi\n", dgrambuf_free_count(dgrambuf));
 	dgrambuf_set_validate_func(dgrambuf, validate_data_dgram);
 }
 
 unsigned int validate_data_dgram(unsigned int nread, void *recvbuf ) {
-	uint32_t seq;
-	uint16_t datalen;
-
-	if ( nread >= 10 && strncmp("data", recvbuf, 4) == 0 ) {
-		seq = ntohl( *( (uint32_t *) recvbuf+1 ) );
-		datalen = ntohs( *( (uint16_t *) recvbuf+4 ) );
-		if ( nread == (10 + datalen) ) {
-			return seq;
-		}
+	if ( nread >= DGRAM_HEADER_SIZE && strncmp("data", recvbuf, 4) == 0 ) {
+		return ntohl( *( (uint32_t *) recvbuf+1 ) );
+	}
+	if ( nread >= 5 && strncmp("final", recvbuf, 5) == 0 ) {
+		return -1;
 	}
 
 	return 0;
-- 
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