int main()
//@ requires true;
//@ ensures true;
{
struct tokenizer* tokenizer = tokenizer_create(my_getchar);
for (;;)
//@ invariant Tokenizer(tokenizer);
{
int result = tokenizer_next(tokenizer);
if (result == -1) break;
print_token(tokenizer);
}
tokenizer_dispose(tokenizer);
puts("The end");
return 0;
}
/**
* Load an AS-level topology in the Subramanian et al format. The
* file format is as follows. Each line describes a directed
* relationship between a two ASes:
* <AS1-number> <AS2-number> <peering-type>
* where peering type can be
* 0 for a peer-to-peer relationship
* 1 for a provider (AS1) to customer (AS2) relationship
* A relationship among two ASes is described in one direction only.
*/
int rexford_parser(FILE * file, as_level_topo_t * topo,
int * line_number)
{
char line[80];
asn_t asn1, asn2;
unsigned int relation;
int error= 0;
net_link_delay_t delay;
gds_tokenizer_t * tokenizer;
const gds_tokens_t * tokens;
as_level_domain_t * domain1, * domain2;
peer_type_t peer_type;
*line_number= 0;
// Parse input file
tokenizer= tokenizer_create(" \t", NULL, NULL);
while ((!feof(file)) && (!error)) {
if (fgets(line, sizeof(line), file) == NULL)
break;
(*line_number)++;
// Skip comments starting with '#'
if (line[0] == '#')
continue;
if (tokenizer_run(tokenizer, line) != TOKENIZER_SUCCESS) {
error= ASLEVEL_ERROR_UNEXPECTED;
break;
}
tokens= tokenizer_get_tokens(tokenizer);
// Set default value for optional parameters
delay= 0;
// Get and check mandatory parameters
if (tokens_get_num(tokens) < 3) {
error= ASLEVEL_ERROR_NUM_PARAMS;
break;
}
// Get and check ASNs
if (str2asn(tokens_get_string_at(tokens, 0), &asn1) ||
str2asn(tokens_get_string_at(tokens, 1), &asn2)) {
error= ASLEVEL_ERROR_INVALID_ASNUM;
break;
}
// Get and check business relationship
if ((tokens_get_uint_at(tokens, 2, &relation) != 0) ||
(_rexford_relation_to_peer_type(relation, &peer_type) != 0)) {
error= ASLEVEL_ERROR_INVALID_RELATION;
break;
}
// Get optional parameters
if (tokens_get_num(tokens) > 3) {
if (str2delay(tokens_get_string_at(tokens, 3), &delay)) {
error= ASLEVEL_ERROR_INVALID_DELAY;
break;
}
}
// Limit number of parameters
if (tokens_get_num(tokens) > 4) {
STREAM_ERR(STREAM_LEVEL_SEVERE,
"Error: too many arguments in topology, line %u\n",
*line_number);
error= ASLEVEL_ERROR_NUM_PARAMS;
break;
}
// Add/get domain 1
if (!(domain1= aslevel_topo_get_as(topo, asn1)) &&
!(domain1= aslevel_topo_add_as(topo, asn1))) {
error= ASLEVEL_ERROR_UNEXPECTED;
break;
}
// Add/get domain 2
if (!(domain2= aslevel_topo_get_as(topo, asn2)) &&
!(domain2= aslevel_topo_add_as(topo, asn2))) {
error= ASLEVEL_ERROR_UNEXPECTED;
break;
}
// Add link in both directions
error= aslevel_as_add_link(domain1, domain2, peer_type, NULL);
if (error != ASLEVEL_SUCCESS)
break;
peer_type= aslevel_reverse_relation(peer_type);
error= aslevel_as_add_link(domain2, domain1, peer_type, NULL);
if (error != ASLEVEL_SUCCESS)
break;
}
tokenizer_destroy(&tokenizer);
return error;
}
