libplugin: datastore helpers.

Plugins are supposed to store their data in the datastore, and commando does so:
let's make it easier for them by providing convenience APIs.

Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
This commit is contained in:
Rusty Russell
2022-07-16 14:30:19 +09:30
parent d3e64c3970
commit 3eccf16f98
2 changed files with 169 additions and 12 deletions

View File

@@ -490,20 +490,18 @@ static struct json_out *start_json_request(const tal_t *ctx,
return jout;
}
/* Synchronous routine to send command and extract fields from response */
void rpc_scan(struct plugin *plugin,
const char *method,
const struct json_out *params TAKES,
const char *guide,
...)
static const char *rpc_scan_core(const tal_t *ctx,
struct plugin *plugin,
const char *method,
const struct json_out *params TAKES,
const char *guide,
va_list ap)
{
bool error;
const char *err;
const jsmntok_t *contents;
int reqlen;
const char *p;
struct json_out *jout;
va_list ap;
jout = start_json_request(tmpctx, 0, method, params);
finish_and_send_json(plugin->rpc_conn->fd, jout);
@@ -514,15 +512,116 @@ void rpc_scan(struct plugin *plugin,
method, reqlen, membuf_elems(&plugin->rpc_conn->mb));
p = membuf_consume(&plugin->rpc_conn->mb, reqlen);
return json_scanv(ctx, p, contents, guide, ap);
}
/* Synchronous routine to send command and extract fields from response */
void rpc_scan(struct plugin *plugin,
const char *method,
const struct json_out *params TAKES,
const char *guide,
...)
{
const char *err;
va_list ap;
va_start(ap, guide);
err = json_scanv(tmpctx, p, contents, guide, ap);
err = rpc_scan_core(tmpctx, plugin, method, params, guide, ap);
va_end(ap);
if (err)
plugin_err(plugin, "Could not parse %s in reply to %s: %s: '%.*s'",
guide, method, err,
reqlen, membuf_elems(&plugin->rpc_conn->mb));
plugin_err(plugin, "Could not parse %s in reply to %s: %s",
guide, method, err);
}
static void json_add_keypath(struct json_out *jout, const char *fieldname, const char *path)
{
char **parts = tal_strsplit(tmpctx, path, "/", STR_EMPTY_OK);
json_out_start(jout, fieldname, '[');
for (size_t i = 0; parts[i]; parts++)
json_out_addstr(jout, NULL, parts[i]);
json_out_end(jout, ']');
}
static bool rpc_scan_datastore(struct plugin *plugin,
const char *path,
const char *hex_or_string,
va_list ap)
{
const char *guide;
struct json_out *params;
const char *err;
params = json_out_new(NULL);
json_out_start(params, NULL, '{');
json_add_keypath(params, "key", path);
json_out_end(params, '}');
json_out_finished(params);
guide = tal_fmt(tmpctx, "{datastore:[0:{%s:%%}]}", hex_or_string);
/* FIXME: Could be some other error, but that's probably a caller bug! */
err = rpc_scan_core(tmpctx, plugin, "listdatastore", take(params), guide, ap);
if (!err)
return true;
plugin_log(plugin, LOG_DBG, "listdatastore error %s: %s", path, err);
return false;
}
bool rpc_scan_datastore_str(struct plugin *plugin,
const char *path,
...)
{
bool ret;
va_list ap;
va_start(ap, path);
ret = rpc_scan_datastore(plugin, path, "string", ap);
va_end(ap);
return ret;
}
/* This variant scans the hex encoding, not the string */
bool rpc_scan_datastore_hex(struct plugin *plugin,
const char *path,
...)
{
bool ret;
va_list ap;
va_start(ap, path);
ret = rpc_scan_datastore(plugin, path, "hex", ap);
va_end(ap);
return ret;
}
struct command_result *jsonrpc_set_datastore_(struct plugin *plugin,
struct command *cmd,
const char *path,
const void *value,
bool value_is_string,
const char *mode,
struct command_result *(*cb)(struct command *command,
const char *buf,
const jsmntok_t *result,
void *arg),
struct command_result *(*errcb)(struct command *command,
const char *buf,
const jsmntok_t *result,
void *arg),
void *arg)
{
struct out_req *req;
req = jsonrpc_request_start(plugin, cmd, "datastore", cb, errcb, arg);
json_add_keypath(req->js->jout, "key", path);
if (value_is_string)
json_add_string(req->js, "string", value);
else
json_add_hex_talarr(req->js, "hex", value);
json_add_string(req->js, "mode", mode);
return send_outreq(plugin, req);
}
static void handle_rpc_reply(struct plugin *plugin, const jsmntok_t *toks)

View File

@@ -160,6 +160,51 @@ struct json_stream *jsonrpc_stream_fail_data(struct command *cmd,
int code,
const char *err);
/* Helper to jsonrpc_request_start() and send_outreq() to update datastore. */
struct command_result *jsonrpc_set_datastore_(struct plugin *plugin,
struct command *cmd,
const char *path,
const void *value,
bool value_is_string,
const char *mode,
struct command_result *(*cb)(struct command *command,
const char *buf,
const jsmntok_t *result,
void *arg),
struct command_result *(*errcb)(struct command *command,
const char *buf,
const jsmntok_t *result,
void *arg),
void *arg);
#define jsonrpc_set_datastore_string(plugin, cmd, path, str, mode, cb, errcb, arg) \
jsonrpc_set_datastore_((plugin), (cmd), (path), (str), true, (mode), \
typesafe_cb_preargs(struct command_result *, void *, \
(cb), (arg), \
struct command *command, \
const char *buf, \
const jsmntok_t *result), \
typesafe_cb_preargs(struct command_result *, void *, \
(errcb), (arg), \
struct command *command, \
const char *buf, \
const jsmntok_t *result), \
(arg))
#define jsonrpc_set_datastore_binary(plugin, cmd, path, tal_ptr, mode, cb, errcb, arg) \
jsonrpc_set_datastore_((plugin), (cmd), (path), (tal_ptr), false, (mode), \
typesafe_cb_preargs(struct command_result *, void *, \
(cb), (arg), \
struct command *command, \
const char *buf, \
const jsmntok_t *result), \
typesafe_cb_preargs(struct command_result *, void *, \
(errcb), (arg), \
struct command *command, \
const char *buf, \
const jsmntok_t *result), \
(arg))
/* This command is finished, here's the response (the content of the
* "result" or "error" field) */
WARN_UNUSED_RESULT
@@ -220,6 +265,19 @@ void rpc_scan(struct plugin *plugin,
const char *guide,
...);
/* Helper to scan datastore: can only be used in init callback. *
Returns false if field does not exist. * path is /-separated. Final
arg is JSON_SCAN or JSON_SCAN_TAL.
*/
bool rpc_scan_datastore_str(struct plugin *plugin,
const char *path,
...);
/* This variant scans the hex encoding, not the string */
bool rpc_scan_datastore_hex(struct plugin *plugin,
const char *path,
...);
/* Send an async rpc request to lightningd. */
struct command_result *send_outreq(struct plugin *plugin,
const struct out_req *req);