Commit 1ae84fcb authored by Roger Dingledine's avatar Roger Dingledine
Browse files

add a 'smartlist' building block that picks random elements from a list


svn:r897
parent 9c66e2bf
......@@ -1009,6 +1009,7 @@ void crypto_pseudo_rand(unsigned int n, unsigned char *to)
}
}
/* return a pseudo random number between 0 and max-1 */
int crypto_pseudo_rand_int(unsigned int max) {
unsigned int val;
unsigned int cutoff;
......
......@@ -33,7 +33,7 @@ void *tor_malloc_zero(size_t size) {
void *tor_realloc(void *ptr, size_t size) {
void *result;
result = realloc(ptr, size);
if (!result) {
log_fn(LOG_ERR, "Out of memory. Dying.");
......@@ -63,6 +63,46 @@ char *tor_strndup(const char *s, size_t n) {
return dup;
}
/*
* A simple smartlist interface to make an unordered list of acceptable
* nodes and then choose a random one.
* smartlist_create() mallocs the list, _free() frees the list,
* _add() adds an element, _remove() removes an element if it's there,
* _choose() returns a random element.
*/
smartlist_t *smartlist_create(int max_elements) {
smartlist_t *sl = tor_malloc(sizeof(smartlist_t));
sl->list = tor_malloc(sizeof(void *) * max_elements);
sl->num_used = 0;
sl->max = max_elements;
return sl;
}
void smartlist_free(smartlist_t *sl) {
free(sl->list);
free(sl);
}
/* add element to the list, but only if there's room */
void smartlist_add(smartlist_t *sl, void *element) {
if(sl->num_used < sl->max)
sl->list[sl->num_used++] = element;
}
void smartlist_remove(smartlist_t *sl, void *element) {
int i;
for(i=0; i < sl->num_used; i++)
if(sl->list[i] == element)
sl->list[i] = sl->list[--sl->num_used]; /* swap with the end */
}
void *smartlist_choose(smartlist_t *sl) {
if(sl->num_used)
return sl->list[crypto_pseudo_rand_int(sl->num_used)];
return NULL; /* no elements to choose from */
}
/*
* String manipulation
*/
......@@ -234,11 +274,11 @@ int read_all(int fd, char *buf, size_t count) {
void set_socket_nonblocking(int socket)
{
#ifdef MS_WINDOWS
/* Yes means no and no means yes. Do you not want to be nonblocking? */
int nonblocking = 0;
ioctlsocket(socket, FIONBIO, (unsigned long*) &nonblocking);
/* Yes means no and no means yes. Do you not want to be nonblocking? */
int nonblocking = 0;
ioctlsocket(socket, FIONBIO, (unsigned long*) &nonblocking);
#else
fcntl(socket, F_SETFL, O_NONBLOCK);
fcntl(socket, F_SETFL, O_NONBLOCK);
#endif
}
......@@ -378,7 +418,7 @@ tor_socketpair(int family, int type, int protocol, int fd[2])
if (listener != -1)
close(listener);
if (connector != -1)
close(connector);
close(connector);
if (acceptor != -1)
close(acceptor);
errno = save_errno;
......@@ -514,7 +554,7 @@ char *read_file_to_str(const char *filename) {
log_fn(LOG_WARN,"Filename %s contains illegal characters.",filename);
return NULL;
}
if(stat(filename, &statbuf) < 0) {
log_fn(LOG_INFO,"Could not stat %s.",filename);
return NULL;
......@@ -616,11 +656,11 @@ get_uname(void)
}
return uname_result;
}
void daemonize(void) {
#ifdef HAVE_DAEMON
if (daemon(0 /* chdir to / */,
0 /* Redirect std* to /dev/null */)) {
0 /* Redirect std* to /dev/null */)) {
log_fn(LOG_ERR, "Daemon returned an error: %s", strerror(errno));
exit(1);
}
......
......@@ -39,6 +39,18 @@ char *tor_strdup(const char *s);
char *tor_strndup(const char *s, size_t n);
#define tor_free(p) do {if(p) {free(p); (p)=NULL;}} while(0)
typedef struct {
void **list;
int num_used;
int max;
} smartlist_t;
smartlist_t *smartlist_create(int max_elements);
void smartlist_free(smartlist_t *sl);
void smartlist_add(smartlist_t *sl, void *element);
void smartlist_remove(smartlist_t *sl, void *element);
void *smartlist_choose(smartlist_t *sl);
const char *eat_whitespace(const char *s);
const char *eat_whitespace_no_nl(const char *s);
const char *find_whitespace(const char *s);
......
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