//the map function
//see ftw(3) man page (dftw is basically identical)
static int map(const char *fpath, const struct stat *sb, int tflag, void *kv) {
off_t size;
uid_t uid;
switch (tflag) {
case FTW_D:
//fpath is a directory
return 0;
case FTW_DNR:
//fpath is a directory which can't be read
fprintf(stderr, "unreadable directory: %s\n", fpath);
return 1;
case FTW_NS:
//the stat(2) call failed on fpath, which is not a symbolic link
fprintf(stderr, "unstatable file: %s\n", fpath);
return 1;
default: {
//(FTW_F)
//ignore symlinks
if (!S_ISLNK(sb->st_mode)) {
size = sb->st_size;
uid = sb->st_uid;
//emit a {uid:size} key/value
MR_kv_add(kv, (char*)&uid, sizeof(uid_t), (char*)&size, sizeof(off_t));
}
return 0;
}
}
}
void generate(int itask, void *kv, void *ptr)
{
RMAT *rmat = (RMAT *) ptr;
int nlevels = rmat->nlevels;
int order = rmat->order;
int ngenerate = rmat->ngenerate;
double a = rmat->a;
double b = rmat->b;
double c = rmat->c;
double d = rmat->d;
double fraction = rmat->fraction;
int i,j,ilevel,delta,m;
double a1,b1,c1,d1,total,rn;
EDGE edge;
for (m = 0; m < ngenerate; m++) {
delta = order >> 1;
a1 = a; b1 = b; c1 = c; d1 = d;
i = j = 0;
for (ilevel = 0; ilevel < nlevels; ilevel++) {
rn = drand48();
if (rn < a1) {
} else if (rn < a1+b1) {
j += delta;
} else if (rn < a1+b1+c1) {
i += delta;
} else {
i += delta;
j += delta;
}
delta /= 2;
if (fraction > 0.0) {
a1 += a1*fraction * (drand48() - 0.5);
b1 += b1*fraction * (drand48() - 0.5);
c1 += c1*fraction * (drand48() - 0.5);
d1 += d1*fraction * (drand48() - 0.5);
total = a1+b1+c1+d1;
a1 /= total;
b1 /= total;
c1 /= total;
d1 /= total;
}
}
edge.vi = i;
edge.vj = j;
MR_kv_add(kv,(char *) &edge,sizeof(EDGE),NULL,0);
}
}
void histo(char *key, int keybytes, char *multivalue,
int nvalues, int *valuebytes, void *kv, void *ptr)
{
MR_kv_add(kv,key,keybytes,(char *) &nvalues,sizeof(int));
}
void degree(char *key, int keybytes, char *multivalue,
int nvalues, int *valuebytes, void *kv, void *ptr)
{
MR_kv_add(kv,(char *) &nvalues,sizeof(int),NULL,0);
}
void nonzero(char *key, int keybytes, char *multivalue,
int nvalues, int *valuebytes, void *kv, void *ptr)
{
EDGE *edge = (EDGE *) key;
MR_kv_add(kv,(char *) &edge->vi,sizeof(VERTEX),NULL,0);
}
void cull(char *key, int keybytes, char *multivalue,
int nvalues, int *valuebytes, void *kv, void *ptr)
{
MR_kv_add(kv,key,keybytes,NULL,0);
}
