Files
palladum-lightning/plugins/askrene/mcf.h
Rusty Russell 07c57b6015 askrene: implement 10-second deadline.
We have another report of looping.  This maxparts code is being completely
rewritten, but it's good to have a catchall for any other cases which might
emerge.

I had to make it customizable since our tests under valgrind are SLOW!

Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
2025-11-03 12:54:37 +10:30

86 lines
3.3 KiB
C

#ifndef LIGHTNING_PLUGINS_ASKRENE_MCF_H
#define LIGHTNING_PLUGINS_ASKRENE_MCF_H
/* Eduardo Quintela's (lagrang3@protonmail.com) Min Cost Flow implementation
* from renepay, as modified to fit askrene */
#include "config.h"
#include <common/amount.h>
#include <common/gossmap.h>
struct route_query;
/**
* optimal_payment_flow - API for min cost flow function(s).
* @ctx: context to allocate returned flows from
* @rq: the route_query we're processing (for logging)
* @source: the source to start from
* @target: the target to pay
* @amount: the amount we want to reach @target
* @mu: 0 = corresponds to only probabilities, 100 corresponds to only fee.
* @delay_feefactor: convert 1 block delay into msat.
* @single_part: don't do MCF at all, just create a single flow.
*
* @delay_feefactor converts 1 block delay into msat, as if it were an additional
* fee. So if a CLTV delay on a node is 5 blocks, that's treated as if it
* were a fee of 5 * @delay_feefactor.
*
* Return a series of subflows which deliver amount to target, or NULL.
*/
struct flow **minflow(const tal_t *ctx,
const struct route_query *rq,
const struct gossmap_node *source,
const struct gossmap_node *target,
struct amount_msat amount,
u32 mu,
double delay_feefactor);
/**
* API for min cost single path.
* @ctx: context to allocate returned flows from
* @rq: the route_query we're processing (for logging)
* @source: the source to start from
* @target: the target to pay
* @amount: the amount we want to reach @target
* @mu: 0 = corresponds to only probabilities, 100 corresponds to only fee.
* @delay_feefactor: convert 1 block delay into msat.
*
* @delay_feefactor converts 1 block delay into msat, as if it were an additional
* fee. So if a CLTV delay on a node is 5 blocks, that's treated as if it
* were a fee of 5 * @delay_feefactor.
*
* Returns an array with one flow which deliver amount to target, or NULL.
*/
struct flow **single_path_flow(const tal_t *ctx, const struct route_query *rq,
const struct gossmap_node *source,
const struct gossmap_node *target,
struct amount_msat amount, u32 mu,
double delay_feefactor);
/* To sanity check: this is the approximation mcf uses for the cost
* of each channel. */
struct amount_msat linear_flow_cost(const struct flow *flow,
struct amount_msat total_amount,
double delay_feefactor);
/* A wrapper to the min. cost flow solver that actually takes into consideration
* the extra msats per channel needed to pay for fees. */
const char *default_routes(const tal_t *ctx, struct route_query *rq,
struct timemono deadline,
const struct gossmap_node *srcnode,
const struct gossmap_node *dstnode,
struct amount_msat amount,
struct amount_msat maxfee, u32 finalcltv,
u32 maxdelay, struct flow ***flows,
double *probability);
/* A wrapper to the single-path constrained solver. */
const char *single_path_routes(const tal_t *ctx, struct route_query *rq,
struct timemono deadline,
const struct gossmap_node *srcnode,
const struct gossmap_node *dstnode,
struct amount_msat amount,
struct amount_msat maxfee, u32 finalcltv,
u32 maxdelay, struct flow ***flows,
double *probability);
#endif /* LIGHTNING_PLUGINS_ASKRENE_MCF_H */