snac2/data.c
2022-10-11 18:54:59 +02:00

1044 lines
24 KiB
C

/* snac - A simple, minimalistic ActivityPub instance */
/* copyright (c) 2022 grunfink - MIT license */
#include "xs.h"
#include "xs_io.h"
#include "xs_json.h"
#include "xs_openssl.h"
#include "xs_glob.h"
#include "snac.h"
#include <time.h>
#include <glob.h>
#include <sys/stat.h>
int srv_open(char *basedir)
/* opens a server */
{
int ret = 0;
xs *cfg_file = NULL;
FILE *f;
d_char *error = NULL;
srv_basedir = xs_str_new(basedir);
if (xs_endswith(srv_basedir, "/"))
srv_basedir = xs_crop(srv_basedir, 0, -1);
cfg_file = xs_fmt("%s/server.json", basedir);
if ((f = fopen(cfg_file, "r")) == NULL)
error = xs_fmt("ERROR: cannot opening '%s'", cfg_file);
else {
xs *cfg_data;
/* read full config file */
cfg_data = xs_readall(f);
/* parse */
srv_config = xs_json_loads(cfg_data);
if (srv_config == NULL)
error = xs_fmt("ERROR: cannot parse '%s'", cfg_file);
else {
char *host;
char *prefix;
char *dbglvl;
char *layout;
double f = 0.0;
host = xs_dict_get(srv_config, "host");
prefix = xs_dict_get(srv_config, "prefix");
dbglvl = xs_dict_get(srv_config, "dbglevel");
layout = xs_dict_get(srv_config, "layout");
if (host == NULL || prefix == NULL)
error = xs_str_new("ERROR: cannot get server data");
else {
srv_baseurl = xs_fmt("https://%s%s", host, prefix);
dbglevel = (int) xs_number_get(dbglvl);
if ((dbglvl = getenv("DEBUG")) != NULL) {
dbglevel = atoi(dbglvl);
error = xs_fmt("DEBUG level set to %d from environment", dbglevel);
}
if (!layout || (f = xs_number_get(layout)) != 2.0)
error = xs_fmt("ERROR: unsupported old disk layout %f\n", f);
else
ret = 1;
}
}
}
if (ret == 0 && error != NULL)
srv_log(error);
return ret;
}
void user_free(snac *snac)
/* frees a user snac */
{
free(snac->uid);
free(snac->basedir);
free(snac->config);
free(snac->key);
free(snac->actor);
}
int user_open(snac *snac, char *uid)
/* opens a user */
{
int ret = 0;
memset(snac, '\0', sizeof(struct _snac));
if (validate_uid(uid)) {
xs *cfg_file;
FILE *f;
snac->uid = xs_str_new(uid);
snac->basedir = xs_fmt("%s/user/%s", srv_basedir, uid);
cfg_file = xs_fmt("%s/user.json", snac->basedir);
if ((f = fopen(cfg_file, "r")) != NULL) {
xs *cfg_data;
/* read full config file */
cfg_data = xs_readall(f);
fclose(f);
if ((snac->config = xs_json_loads(cfg_data)) != NULL) {
xs *key_file = xs_fmt("%s/key.json", snac->basedir);
if ((f = fopen(key_file, "r")) != NULL) {
xs *key_data;
key_data = xs_readall(f);
fclose(f);
if ((snac->key = xs_json_loads(key_data)) != NULL) {
snac->actor = xs_fmt("%s/%s", srv_baseurl, uid);
ret = 1;
}
else
srv_log(xs_fmt("cannot parse '%s'", key_file));
}
else
srv_log(xs_fmt("error opening '%s'", key_file));
}
else
srv_log(xs_fmt("cannot parse '%s'", cfg_file));
}
else
srv_debug(2, xs_fmt("error opening '%s'", cfg_file));
}
else
srv_log(xs_fmt("invalid user '%s'", uid));
if (!ret)
user_free(snac);
return ret;
}
d_char *user_list(void)
/* returns the list of user ids */
{
xs *spec = xs_fmt("%s/user/" "*", srv_basedir);
return xs_glob(spec, 1, 0);
}
double mtime(char *fn)
/* returns the mtime of a file or directory, or 0.0 */
{
struct stat st;
double r = 0.0;
if (fn && stat(fn, &st) != -1)
r = (double)st.st_mtim.tv_sec;
return r;
}
d_char *_follower_fn(snac *snac, char *actor)
{
xs *md5 = xs_md5_hex(actor, strlen(actor));
return xs_fmt("%s/followers/%s.json", snac->basedir, md5);
}
int follower_add(snac *snac, char *actor, char *msg)
/* adds a follower */
{
int ret = 201; /* created */
xs *fn = _follower_fn(snac, actor);
FILE *f;
if ((f = fopen(fn, "w")) != NULL) {
xs *j = xs_json_dumps_pp(msg, 4);
fwrite(j, 1, strlen(j), f);
fclose(f);
}
else
ret = 500;
snac_debug(snac, 2, xs_fmt("follower_add %s %s", actor, fn));
return ret;
}
int follower_del(snac *snac, char *actor)
/* deletes a follower */
{
int status = 200;
xs *fn = _follower_fn(snac, actor);
if (fn != NULL)
unlink(fn);
else
status = 404;
snac_debug(snac, 2, xs_fmt("follower_del %s %s", actor, fn));
return status;
}
int follower_check(snac *snac, char *actor)
/* checks if someone is a follower */
{
xs *fn = _follower_fn(snac, actor);
return !!(mtime(fn) != 0.0);
}
d_char *follower_list(snac *snac)
/* returns the list of followers */
{
xs *spec = xs_fmt("%s/followers/" "*.json", snac->basedir);
xs *glist = xs_glob(spec, 0, 0);
char *p, *v;
d_char *list = xs_list_new();
/* iterate the list of files */
p = glist;
while (xs_list_iter(&p, &v)) {
FILE *f;
/* load the follower data */
if ((f = fopen(v, "r")) != NULL) {
xs *j = xs_readall(f);
fclose(f);
if (j != NULL) {
xs *o = xs_json_loads(j);
if (o != NULL)
list = xs_list_append(list, o);
}
}
}
return list;
}
double timeline_mtime(snac *snac)
{
xs *fn = xs_fmt("%s/timeline", snac->basedir);
return mtime(fn);
}
d_char *_timeline_find_fn(snac *snac, char *id)
/* returns the file name of a timeline entry by its id */
{
xs *md5 = xs_md5_hex(id, strlen(id));
xs *spec = xs_fmt("%s/timeline/" "*-%s.json", snac->basedir, md5);
xs *list = NULL;
d_char *fn = NULL;
int l;
list = xs_glob(spec, 0, 0);
l = xs_list_len(list);
/* if there is something, get the first one */
if (l > 0) {
fn = xs_str_new(xs_list_get(list, 0));
if (l > 1)
snac_log(snac, xs_fmt("**ALERT** _timeline_find_fn %d > 1", l));
}
return fn;
}
int timeline_here(snac *snac, char *id)
/* checks if an object is already downloaded */
{
xs *fn = _timeline_find_fn(snac, id);
return fn != NULL;
}
d_char *timeline_find(snac *snac, char *id)
/* gets a message from the timeline by id */
{
xs *fn = _timeline_find_fn(snac, id);
d_char *msg = NULL;
if (fn != NULL) {
FILE *f;
if ((f = fopen(fn, "r")) != NULL) {
xs *j = xs_readall(f);
msg = xs_json_loads(j);
fclose(f);
}
}
return msg;
}
void timeline_del(snac *snac, char *id)
/* deletes a message from the timeline */
{
xs *fn = _timeline_find_fn(snac, id);
if (fn != NULL) {
xs *lfn = NULL;
unlink(fn);
snac_debug(snac, 1, xs_fmt("timeline_del %s", id));
/* try to delete also from the local timeline */
lfn = xs_replace(fn, "/timeline/", "/local/");
if (unlink(lfn) != -1)
snac_debug(snac, 1, xs_fmt("timeline_del (local) %s", id));
}
}
d_char *timeline_get(snac *snac, char *fn)
/* gets a timeline entry by file name */
{
d_char *d = NULL;
FILE *f;
if ((f = fopen(fn, "r")) != NULL) {
xs *j = xs_readall(f);
d = xs_json_loads(j);
fclose(f);
}
return d;
}
d_char *_timeline_list(snac *snac, char *directory, int max)
/* returns a list of the timeline filenames */
{
xs *spec = xs_fmt("%s/%s/" "*.json", snac->basedir, directory);
int c_max;
/* maximum number of items in the timeline */
c_max = xs_number_get(xs_dict_get(srv_config, "max_timeline_entries"));
/* never more timeline entries than the configured maximum */
if (max > c_max)
max = c_max;
return xs_glob_n(spec, 0, 1, max);
}
d_char *timeline_list(snac *snac, int max)
{
return _timeline_list(snac, "timeline", max);
}
d_char *local_list(snac *snac, int max)
{
return _timeline_list(snac, "local", max);
}
d_char *_timeline_new_fn(snac *snac, char *id)
/* creates a new filename */
{
xs *ntid = tid(0);
xs *md5 = xs_md5_hex(id, strlen(id));
return xs_fmt("%s/timeline/%s-%s.json", snac->basedir, ntid, md5);
}
void _timeline_write(snac *snac, char *id, char *msg, char *parent, char *referrer)
/* writes a timeline entry and refreshes the ancestors */
{
xs *fn = _timeline_new_fn(snac, id);
FILE *f;
if ((f = fopen(fn, "w")) != NULL) {
xs *j = xs_json_dumps_pp(msg, 4);
fwrite(j, strlen(j), 1, f);
fclose(f);
snac_debug(snac, 1, xs_fmt("_timeline_write %s %s", id, fn));
}
/* related to this user? link to local timeline */
if (xs_startswith(id, snac->actor) ||
(!xs_is_null(parent) && xs_startswith(parent, snac->actor)) ||
(!xs_is_null(referrer) && xs_startswith(referrer, snac->actor))) {
xs *lfn = xs_replace(fn, "/timeline/", "/local/");
link(fn, lfn);
snac_debug(snac, 1, xs_fmt("_timeline_write (local) %s %s", id, lfn));
}
if (!xs_is_null(parent)) {
/* update the parent, adding this id to its children list */
xs *pfn = _timeline_find_fn(snac, parent);
xs *p_msg = NULL;
if (pfn != NULL && (f = fopen(pfn, "r")) != NULL) {
xs *j;
j = xs_readall(f);
fclose(f);
p_msg = xs_json_loads(j);
}
if (p_msg == NULL)
return;
xs *meta = xs_dup(xs_dict_get(p_msg, "_snac"));
xs *children = xs_dup(xs_dict_get(meta, "children"));
/* add the child if it's not already there */
if (xs_list_in(children, id) == -1)
children = xs_list_append(children, id);
/* re-store */
meta = xs_dict_set(meta, "children", children);
p_msg = xs_dict_set(p_msg, "_snac", meta);
xs *nfn = _timeline_new_fn(snac, parent);
if ((f = fopen(nfn, "w")) != NULL) {
xs *j = xs_json_dumps_pp(p_msg, 4);
fwrite(j, strlen(j), 1, f);
fclose(f);
unlink(pfn);
snac_debug(snac, 1,
xs_fmt("_timeline_write updated parent %s %s", parent, nfn));
/* try to do the same with the local */
xs *olfn = xs_replace(pfn, "/timeline/", "/local/");
if (unlink(olfn) != -1 || xs_startswith(id, snac->actor)) {
xs *nlfn = xs_replace(nfn, "/timeline/", "/local/");
link(nfn, nlfn);
snac_debug(snac, 1,
xs_fmt("_timeline_write updated parent (local) %s %s", parent, nlfn));
}
}
else
return;
/* now iterate all parents up, just renaming the files */
xs *grampa = xs_dup(xs_dict_get(meta, "parent"));
while (!xs_is_null(grampa)) {
xs *gofn = _timeline_find_fn(snac, grampa);
if (gofn == NULL)
break;
/* create the new filename */
xs *gnfn = _timeline_new_fn(snac, grampa);
rename(gofn, gnfn);
snac_debug(snac, 1,
xs_fmt("_timeline_write updated grampa %s %s", grampa, gnfn));
/* try to do the same with the local */
xs *golfn = xs_replace(gofn, "/timeline/", "/local/");
if (unlink(golfn) != -1) {
xs *gnlfn = xs_replace(gnfn, "/timeline/", "/local/");
link(gnfn, gnlfn);
snac_debug(snac, 1,
xs_fmt("_timeline_write updated grampa (local) %s %s", parent, gnlfn));
}
/* now open it and get its own parent */
if ((f = fopen(gnfn, "r")) != NULL) {
xs *j = xs_readall(f);
fclose(f);
xs *g_msg = xs_json_loads(j);
d_char *meta = xs_dict_get(g_msg, "_snac");
d_char *p = xs_dict_get(meta, "parent");
free(grampa);
grampa = xs_dup(p);
}
}
}
}
int timeline_add(snac *snac, char *id, char *o_msg, char *parent, char *referrer)
/* adds a message to the timeline */
{
xs *pfn = _timeline_find_fn(snac, id);
if (pfn != NULL) {
snac_log(snac, xs_fmt("timeline_add refusing rewrite %s %s", id, pfn));
return 0;
}
xs *msg = xs_dup(o_msg);
xs *md;
/* add new metadata */
md = xs_json_loads("{"
"\"children\": [],"
"\"liked_by\": [],"
"\"announced_by\": [],"
"\"version\": \"" USER_AGENT "\","
"\"referrer\": null,"
"\"parent\": null"
"}");
if (!xs_is_null(parent))
md = xs_dict_set(md, "parent", parent);
if (!xs_is_null(referrer))
md = xs_dict_set(md, "referrer", referrer);
msg = xs_dict_set(msg, "_snac", md);
_timeline_write(snac, id, msg, parent, referrer);
snac_debug(snac, 1, xs_fmt("timeline_add %s", id));
return 1;
}
void timeline_admire(snac *snac, char *id, char *admirer, int like)
/* updates a timeline entry with a new admiration */
{
xs *ofn = _timeline_find_fn(snac, id);
FILE *f;
if (ofn != NULL && (f = fopen(ofn, "r")) != NULL) {
xs *j1 = xs_readall(f);
fclose(f);
xs *msg = xs_json_loads(j1);
xs *meta = xs_dup(xs_dict_get(msg, "_snac"));
xs *list;
if (like)
list = xs_dup(xs_dict_get(meta, "liked_by"));
else
list = xs_dup(xs_dict_get(meta, "announced_by"));
/* add the admirer if it's not already there */
if (xs_list_in(list, admirer) == -1)
list = xs_list_append(list, admirer);
/* set the admirer as the referrer */
if (!like)
meta = xs_dict_set(meta, "referrer", admirer);
/* re-store */
if (like)
meta = xs_dict_set(meta, "liked_by", list);
else
meta = xs_dict_set(meta, "announced_by", list);
msg = xs_dict_set(msg, "_snac", meta);
unlink(ofn);
ofn = xs_replace_i(ofn, "/timeline/", "/local/");
unlink(ofn);
_timeline_write(snac, id, msg, xs_dict_get(meta, "parent"), admirer);
snac_debug(snac, 1, xs_fmt("timeline_admire (%s) %s %s",
like ? "Like" : "Announce", id, admirer));
}
else
snac_log(snac, xs_fmt("timeline_admire ignored for unknown object %s", id));
}
d_char *_following_fn(snac *snac, char *actor)
{
xs *md5 = xs_md5_hex(actor, strlen(actor));
return xs_fmt("%s/following/%s.json", snac->basedir, md5);
}
int following_add(snac *snac, char *actor, char *msg)
/* adds to the following list */
{
int ret = 201; /* created */
xs *fn = _following_fn(snac, actor);
FILE *f;
if ((f = fopen(fn, "w")) != NULL) {
xs *j = xs_json_dumps_pp(msg, 4);
fwrite(j, 1, strlen(j), f);
fclose(f);
}
else
ret = 500;
snac_debug(snac, 2, xs_fmt("following_add %s %s", actor, fn));
return ret;
}
int following_del(snac *snac, char *actor)
/* someone is no longer following us */
{
xs *fn = _following_fn(snac, actor);
unlink(fn);
snac_debug(snac, 2, xs_fmt("following_del %s %s", actor, fn));
return 200;
}
int following_check(snac *snac, char *actor)
/* checks if someone is following us */
{
xs *fn = _following_fn(snac, actor);
return !!(mtime(fn) != 0.0);
}
int following_get(snac *snac, char *actor, d_char **data)
/* returns the 'Follow' object */
{
xs *fn = _following_fn(snac, actor);
FILE *f;
int status = 200;
if ((f = fopen(fn, "r")) != NULL) {
xs *j = xs_readall(f);
fclose(f);
*data = xs_json_loads(j);
}
else
status = 404;
return status;
}
d_char *_muted_fn(snac *snac, char *actor)
{
xs *md5 = xs_md5_hex(actor, strlen(actor));
return xs_fmt("%s/muted/%s.json", snac->basedir, md5);
}
void mute(snac *snac, char *actor)
/* mutes a moron */
{
xs *fn = _muted_fn(snac, actor);
FILE *f;
if ((f = fopen(fn, "w")) != NULL) {
fprintf(f, "%s\n", actor);
fclose(f);
snac_debug(snac, 2, xs_fmt("muted %s %s", actor, fn));
}
}
void unmute(snac *snac, char *actor)
/* actor is no longer a moron */
{
xs *fn = _muted_fn(snac, actor);
unlink(fn);
snac_debug(snac, 2, xs_fmt("unmuted %s %s", actor, fn));
}
int is_muted(snac *snac, char *actor)
/* check if someone is muted */
{
xs *fn = _muted_fn(snac, actor);
return !!(mtime(fn) != 0.0);
}
d_char *_actor_fn(snac *snac, char *actor)
/* returns the file name for an actor */
{
xs *md5 = xs_md5_hex(actor, strlen(actor));
return xs_fmt("%s/actors/%s.json", snac->basedir, md5);
}
int actor_add(snac *snac, char *actor, char *msg)
/* adds an actor */
{
int ret = 201; /* created */
xs *fn = _actor_fn(snac, actor);
FILE *f;
if ((f = fopen(fn, "w")) != NULL) {
xs *j = xs_json_dumps_pp(msg, 4);
fwrite(j, 1, strlen(j), f);
fclose(f);
}
else
ret = 500;
snac_debug(snac, 2, xs_fmt("actor_add %s %s", actor, fn));
return ret;
}
int actor_get(snac *snac, char *actor, d_char **data)
/* returns an already downloaded actor */
{
xs *fn = _actor_fn(snac, actor);
double t;
double max_time;
int status;
FILE *f;
t = mtime(fn);
/* no mtime? there is nothing here */
if (t == 0.0)
return 404;
/* maximum time for the actor data to be considered stale */
max_time = 3600.0 * 36.0;
if (t + max_time < (double) time(NULL)) {
/* actor data exists but also stinks */
if ((f = fopen(fn, "a")) != NULL) {
/* write a blank at the end to 'touch' the file */
fwrite(" ", 1, 1, f);
fclose(f);
}
status = 205; /* "205: Reset Content" "110: Response Is Stale" */
}
else {
/* it's still valid */
status = 200;
}
if ((f = fopen(fn, "r")) != NULL) {
xs *j = xs_readall(f);
fclose(f);
if (data)
*data = xs_json_loads(j);
}
else
status = 500;
return status;
}
d_char *_static_fn(snac *snac, char *id)
/* gets the filename for a static file */
{
return xs_fmt("%s/static/%s", snac->basedir, id);
}
int static_get(snac *snac, char *id, d_char **data, int *size)
/* returns static content */
{
xs *fn = _static_fn(snac, id);
FILE *f;
int status = 404;
*size = 0xfffffff;
if ((f = fopen(fn, "rb")) != NULL) {
*data = xs_read(f, size);
status = 200;
}
return status;
}
d_char *_history_fn(snac *snac, char *id)
/* gets the filename for the history */
{
return xs_fmt("%s/history/%s", snac->basedir, id);
}
double history_mtime(snac *snac, char * id)
{
double t = 0.0;
xs *fn = _history_fn(snac, id);
if (fn != NULL)
t = mtime(fn);
return t;
}
void history_add(snac *snac, char *id, char *content, int size)
/* adds something to the history */
{
xs *fn = _history_fn(snac, id);
FILE *f;
if ((f = fopen(fn, "w")) != NULL) {
fwrite(content, size, 1, f);
fclose(f);
}
}
d_char *history_get(snac *snac, char *id)
{
d_char *content = NULL;
xs *fn = _history_fn(snac, id);
FILE *f;
if ((f = fopen(fn, "r")) != NULL) {
content = xs_readall(f);
fclose(f);
}
return content;
}
int history_del(snac *snac, char *id)
{
xs *fn = _history_fn(snac, id);
return unlink(fn);
}
d_char *history_list(snac *snac)
{
xs *spec = xs_fmt("%s/history/" "*.html", snac->basedir);
return xs_glob(spec, 1, 0);
}
static int _enqueue_put(char *fn, char *msg)
/* writes safely to the queue */
{
int ret = 1;
xs *tfn = xs_fmt("%s.tmp", fn);
FILE *f;
if ((f = fopen(tfn, "w")) != NULL) {
xs *j = xs_json_dumps_pp(msg, 4);
fwrite(j, strlen(j), 1, f);
fclose(f);
rename(tfn, fn);
}
else
ret = 0;
return ret;
}
void enqueue_input(snac *snac, char *msg, char *req, int retries)
/* enqueues an input message */
{
int qrt = xs_number_get(xs_dict_get(srv_config, "queue_retry_minutes"));
xs *ntid = tid(retries * 60 * qrt);
xs *fn = xs_fmt("%s/queue/%s.json", snac->basedir, ntid);
xs *qmsg = xs_dict_new();
xs *rn = xs_number_new(retries);
qmsg = xs_dict_append(qmsg, "type", "input");
qmsg = xs_dict_append(qmsg, "object", msg);
qmsg = xs_dict_append(qmsg, "req", req);
qmsg = xs_dict_append(qmsg, "retries", rn);
_enqueue_put(fn, qmsg);
snac_debug(snac, 1, xs_fmt("enqueue_input %s", fn));
}
void enqueue_output(snac *snac, char *msg, char *actor, int retries)
/* enqueues an output message for an actor */
{
if (strcmp(actor, snac->actor) == 0) {
snac_debug(snac, 1, xs_str_new("enqueue refused to myself"));
return;
}
int qrt = xs_number_get(xs_dict_get(srv_config, "queue_retry_minutes"));
xs *ntid = tid(retries * 60 * qrt);
xs *fn = xs_fmt("%s/queue/%s.json", snac->basedir, ntid);
xs *qmsg = xs_dict_new();
xs *rn = xs_number_new(retries);
qmsg = xs_dict_append(qmsg, "type", "output");
qmsg = xs_dict_append(qmsg, "actor", actor);
qmsg = xs_dict_append(qmsg, "object", msg);
qmsg = xs_dict_append(qmsg, "retries", rn);
_enqueue_put(fn, qmsg);
snac_debug(snac, 1, xs_fmt("enqueue_output %s %s %d", actor, fn, retries));
}
d_char *queue(snac *snac)
/* returns a list with filenames that can be dequeued */
{
xs *spec = xs_fmt("%s/queue/" "*.json", snac->basedir);
d_char *list = xs_list_new();
glob_t globbuf;
time_t t = time(NULL);
if (glob(spec, 0, NULL, &globbuf) == 0) {
int n;
char *p;
for (n = 0; (p = globbuf.gl_pathv[n]) != NULL; n++) {
/* get the retry time from the basename */
char *bn = strrchr(p, '/');
time_t t2 = atol(bn + 1);
if (t2 > t)
snac_debug(snac, 2, xs_fmt("queue not yet time for %s", p));
else {
list = xs_list_append(list, p);
snac_debug(snac, 2, xs_fmt("queue ready for %s", p));
}
}
}
globfree(&globbuf);
return list;
}
d_char *dequeue(snac *snac, char *fn)
/* dequeues a message */
{
FILE *f;
d_char *obj = NULL;
if ((f = fopen(fn, "r")) != NULL) {
/* delete right now */
unlink(fn);
xs *j = xs_readall(f);
obj = xs_json_loads(j);
fclose(f);
}
return obj;
}
void purge(snac *snac)
/* do the purge */
{
int tpd = xs_number_get(xs_dict_get(srv_config, "timeline_purge_days"));
time_t mt = time(NULL) - tpd * 24 * 3600;
char *p, *v;
xs *t_spec = xs_fmt("%s/timeline/" "*.json", snac->basedir);
xs *t_list = xs_glob(t_spec, 0, 0);
p = t_list;
while (xs_list_iter(&p, &v)) {
if (mtime(v) < mt) {
/* older than the minimum time: delete it */
unlink(v);
snac_debug(snac, 1, xs_fmt("purged %s", v));
}
}
xs *a_spec = xs_fmt("%s/actors/" "*.json", snac->basedir);
xs *a_list = xs_glob(a_spec, 0, 0);
p = a_list;
while (xs_list_iter(&p, &v)) {
if (mtime(v) < mt) {
/* older than the minimum time: delete it */
unlink(v);
snac_debug(snac, 1, xs_fmt("purged %s", v));
}
}
}