struct watchman_trigger_command *w_build_trigger_from_def(
w_root_t *root, json_t *trig, char **errmsg)
{
struct watchman_trigger_command *cmd;
json_t *ele, *query;
json_int_t jint;
const char *name = NULL;
cmd = calloc(1, sizeof(*cmd));
if (!cmd) {
*errmsg = strdup("no memory");
return NULL;
}
cmd->definition = trig;
json_incref(cmd->definition);
query = json_pack("{s:O}", "expression",
json_object_get(cmd->definition, "expression"));
cmd->query = w_query_parse(query, errmsg);
json_decref(query);
if (!cmd->query) {
w_trigger_command_free(cmd);
return NULL;
}
json_unpack(trig, "{s:s}", "name", &name);
if (!name) {
*errmsg = strdup("invalid or missing name");
w_trigger_command_free(cmd);
return NULL;
}
cmd->triggername = w_string_new(name);
cmd->command = json_object_get(trig, "command");
if (cmd->command) {
json_incref(cmd->command);
}
if (!cmd->command || !json_is_array(cmd->command) ||
!json_array_size(cmd->command)) {
*errmsg = strdup("invalid command array");
w_trigger_command_free(cmd);
return NULL;
}
json_unpack(trig, "{s:b}", "append_files", &cmd->append_files);
ele = json_object_get(trig, "stdin");
if (!ele) {
cmd->stdin_style = input_dev_null;
} else if (json_is_array(ele)) {
cmd->stdin_style = input_json;
if (!parse_field_list(ele, &cmd->field_list, errmsg)) {
w_trigger_command_free(cmd);
return NULL;
}
} else if (json_is_string(ele)) {
const char *str = json_string_value(ele);
if (!strcmp(str, "/dev/null")) {
cmd->stdin_style = input_dev_null;
} else if (!strcmp(str, "NAME_PER_LINE")) {
cmd->stdin_style = input_name_list;
} else {
ignore_result(asprintf(errmsg, "invalid stdin value %s", str));
w_trigger_command_free(cmd);
return NULL;
}
} else {
*errmsg = strdup("invalid value for stdin");
w_trigger_command_free(cmd);
return NULL;
}
jint = 0; // unlimited unless specified
json_unpack(trig, "{s:I}", "max_files_stdin", &jint);
if (jint < 0) {
*errmsg = strdup("max_files_stdin must be >= 0");
w_trigger_command_free(cmd);
return NULL;
}
cmd->max_files_stdin = jint;
json_unpack(trig, "{s:s}", "stdout", &cmd->stdout_name);
json_unpack(trig, "{s:s}", "stderr", &cmd->stderr_name);
if (!parse_redirection(&cmd->stdout_name, &cmd->stdout_flags,
"stdout", errmsg)) {
w_trigger_command_free(cmd);
return NULL;
}
if (!parse_redirection(&cmd->stderr_name, &cmd->stderr_flags,
"stderr", errmsg)) {
w_trigger_command_free(cmd);
return NULL;
}
// Copy current environment
cmd->envht = w_envp_make_ht();
// Set some standard vars
w_envp_set(cmd->envht, "WATCHMAN_ROOT", root->root_path);
w_envp_set_cstring(cmd->envht, "WATCHMAN_SOCK", get_sock_name());
w_envp_set(cmd->envht, "WATCHMAN_TRIGGER", cmd->triggername);
return cmd;
}
/* trigger /root triggername [watch patterns] -- cmd to run
* Sets up a trigger so that we can execute a command when a change
* is detected */
static void cmd_trigger(struct watchman_client *client, json_t *args)
{
w_root_t *root;
struct watchman_trigger_command *cmd, *old;
json_t *resp;
json_t *trig;
char *errmsg = NULL;
bool need_save = true;
root = resolve_root_or_err(client, args, 1, true);
if (!root) {
return;
}
if (json_array_size(args) < 3) {
send_error_response(client, "not enough arguments");
goto done;
}
trig = json_array_get(args, 2);
if (json_is_string(trig)) {
trig = build_legacy_trigger(root, client, args);
if (!trig) {
goto done;
}
} else {
// Add a ref so that we don't need to conditionally decref later
// for the legacy case later
json_incref(trig);
}
cmd = w_build_trigger_from_def(root, trig, &errmsg);
json_decref(trig);
if (!cmd) {
send_error_response(client, "%s", errmsg);
goto done;
}
resp = make_response();
set_prop(resp, "triggerid", json_string_nocheck(cmd->triggername->buf));
w_root_lock(root);
old = w_ht_val_ptr(w_ht_get(root->commands,
w_ht_ptr_val(cmd->triggername)));
if (old && json_equal(cmd->definition, old->definition)) {
// Same definition: we don't and shouldn't touch things, so that we
// preserve the associated trigger clock and don't cause the trigger
// to re-run immediately
set_prop(resp, "disposition", json_string_nocheck("already_defined"));
w_trigger_command_free(cmd);
cmd = NULL;
need_save = false;
} else {
set_prop(resp, "disposition", json_string_nocheck(
old ? "replaced" : "created"));
w_ht_replace(root->commands, w_ht_ptr_val(cmd->triggername),
w_ht_ptr_val(cmd));
// Force the trigger to be eligible to run now
root->ticks++;
root->pending_trigger_tick = root->ticks;
}
w_root_unlock(root);
if (need_save) {
w_state_save();
}
send_and_dispose_response(client, resp);
done:
if (errmsg) {
free(errmsg);
}
w_root_delref(root);
}
