rgb-cln/common/interactivetx.h

93 lines
3.1 KiB
C

#ifndef LIGHTNING_COMMON_INTERACTIVETX_H
#define LIGHTNING_COMMON_INTERACTIVETX_H
#include "config.h"
#include <ccan/short_types/short_types.h>
#include <common/channel_id.h>
#include <common/per_peer_state.h>
#include <common/tx_roles.h>
#include <common/utils.h>
#include <wally_psbt.h>
/* Interactive tx handles the building and updating of a transaction between
* two peers. A PSBT is passed back and forth between two peers in steps. In
* each step a peer can suggest a single change or signal they're done
* updating with WIRE_TX_COMPLETE. Once two steps in a row result in
* WIRE_TX_COMPLETE the transaction is considered complete.
*/
#define INTERACTIVETX_NUM_TX_MSGS (TX_RM_OUTPUT + 1)
enum tx_msgs {
TX_ADD_INPUT,
TX_ADD_OUTPUT,
TX_RM_INPUT,
TX_RM_OUTPUT,
};
struct interactivetx_context {
enum tx_role our_role;
struct per_peer_state *pps;
struct channel_id channel_id;
/* Track how many of each tx collab msg we receive */
u16 tx_add_input_count, tx_add_output_count;
/* Returns a PSBT with at least one change to the transaction as
* compared to ictx->current_psbt.
*
* If set to NULL, the default implementation will simply return
* ictx->desired_psbt.
*
* If no more changes are demanded, return NULL or current_psbt
* unchanged to signal completion.
*/
struct wally_psbt *(*next_update_fn)(const tal_t *ctx,
struct interactivetx_context *ictx);
/* Set this to the intial psbt. Defaults to an empty PSBT. */
struct wally_psbt *current_psbt;
/* Optional field for storing your side's desired psbt state, to be
* used inside 'next_update_fn'.
*/
struct wally_psbt *desired_psbt;
/* If true, process_interactivetx_updates will return when local changes
* are exhausted and 'tx_complete' will not be sent.
*/
bool pause_when_complete;
/* Internal cached change set */
struct psbt_changeset *change_set;
};
/* Builds a new default interactivetx context with default values */
struct interactivetx_context *new_interactivetx_context(const tal_t *ctx,
enum tx_role our_role,
struct per_peer_state *pps,
struct channel_id channel_id);
/* Blocks the thread until we run out of changes (and we send tx_complete),
* or an error occurs. If 'pause_when_complete' on the `interactivetx_context`
* is set, this behavior changes and we return without sending tx_complete.
*
* If received_tx_complete is not NULL:
* in -> true means we assume we've received tx_complete in a previous round.
* out -> true means the last message from the peer was 'tx_complete'.
*
* Returns NULL on success or a description of the error on failure.
*/
char *process_interactivetx_updates(const tal_t *ctx,
struct interactivetx_context *ictx,
bool *received_tx_complete);
/* If the given ictx would cause `process_interactivetx_updates to send tx
* changes when called. Returns true if an error occurs
* (call `process_interactivetx_updates` for a description of the error).
*/
bool interactivetx_has_changes(struct interactivetx_context *ictx,
struct wally_psbt *next_psbt);
#endif /* LIGHTNING_COMMON_INTERACTIVETX_H */