[nethist] Experimental implementation of taking snapshots

nethist/nethist.c

 #include <stdio.h>
 #include <stdlib.h>
+#include <unistd.h>
+#include <string.h>
 #include <stdbool.h>
 
 #define BUFFSIZE 512
@@ -11,7 +13,7 @@
 #define MAX_LEN_INTERFACE_LIST 20
 
 struct network_configuration {
-	char interfaces[MAX_LEN_INTERFACE_LIST];
+	char interfaces[MAX_LEN_INTERFACE_LIST][MAX_LEN_INTERFACE_NAME];
 	size_t interfaces_cnt;
 };
 
@@ -21,8 +23,13 @@ typedef struct {
 
 configuration g_config;
 
+struct newtwork_interface_data {
+	unsigned long long r_bytes;
+	unsigned long long t_bytes;
+};
+
 struct network_snapshot {
-	unsigned long long interface[MAX_LEN_INTERFACE_LIST];
+	struct newtwork_interface_data interface[MAX_LEN_INTERFACE_LIST];
 };
 
 typedef struct {
@@ -30,11 +37,21 @@ typedef struct {
 	//struct cpu_snapshot cpu; //etc. etc.
 } snapshot;
 
-
 static void network_init_snapshot(struct network_snapshot *snapshot) {
 	for (size_t i = 0; i < MAX_LEN_INTERFACE_LIST; i++) {
-		snapshot->interface[i] = 0;
+		snapshot->interface[i].r_bytes = 0;
+		snapshot->interface[i].t_bytes = 0;
+	}
+}
+
+static size_t network_get_interface_number(char *name) {
+	for (size_t i = 0; i < g_config.network.interfaces_cnt; i++) {
+		if (strcmp(name, g_config.network.interfaces[i]) == 0) {
+			return i;
+		}
 	}
+
+	return g_config.network.interfaces_cnt;
 }
 
 static bool network_init_global() {
@@ -52,7 +69,7 @@ static bool network_init_global() {
 	g_config.network.interfaces_cnt = 0;
 
 	while (fgets(buffer, BUFFSIZE, f) != NULL) {
-		sscanf(buffer, "%20s", &g_config.network.interfaces[g_config.network.interfaces_cnt++]);
+		sscanf(buffer, "%20s", g_config.network.interfaces[g_config.network.interfaces_cnt++]);
 	}
 
 	fclose(f);
@@ -72,11 +89,27 @@ static bool network_take_snapshot(struct network_snapshot *snap) {
 		}
 	}
 
+	char name[MAX_LEN_INTERFACE_NAME];
+	size_t pos;
+	unsigned long long r_bytes, t_bytes, dummy;
 	while (fgets(buffer, BUFFSIZE, f) != NULL) {
+		sscanf(buffer, "%20s%llu%llu%llu%llu%llu%llu%llu%llu%llu%llu%llu%llu%llu%llu%llu%llu",
+			name, &r_bytes,
+			&dummy, &dummy, &dummy, &dummy, &dummy, &dummy, &dummy,
+			&t_bytes,
+			&dummy, &dummy, &dummy, &dummy, &dummy, &dummy, &dummy
+		);
+
+		pos = network_get_interface_number(name);
+		if (pos == g_config.network.interfaces_cnt) {
+			printf("INTERRUPT\n");
+			exit(1);
+		}
 
+		snap->interface[pos].r_bytes = r_bytes;
+		snap->interface[pos].t_bytes = t_bytes;
 	}
 
-
 	fclose(f);
 
 	return true;
@@ -94,6 +127,22 @@ static void take_snapshot(snapshot *snap) {
 	network_take_snapshot(&(snap->network));
 }
 
+static void network_print_history(FILE *stream, int time, struct network_snapshot *snap) {
+	for (size_t i = 0; i < g_config.network.interfaces_cnt; i++) {
+		fprintf(stream, "%d,%s,%llu,%llu\n", time, g_config.network.interfaces[i], snap->interface[i].r_bytes, snap->interface[i].t_bytes);
+	}
+}
+
+static void print_history(FILE *stream, snapshot *snapshots, size_t from) {
+	size_t pos = from;
+
+	for (int i = 0; i < SNAPSHOT_COUNT; i++) {
+		network_print_history(stream, i, &(snapshots[pos].network));
+		pos = (pos + 1) % SNAPSHOT_COUNT;
+	}
+
+}
+
 int main(int argc, char **argv) {
 	(void) argc; (void) argv;
 
@@ -112,8 +161,11 @@ int main(int argc, char **argv) {
 
 		take_snapshot(&(snapshots[write_to]));
 
+		print_history(stdout, snapshots, write_to);
 
 		write_to++;
+
+		usleep(SLEEP_TIME_USEC);
 	}