core-lightning/common/gossmap.h
Rusty Russell 016e332304 gossmap: add functions to map index back to node/chan.
Useful if you want to store per-chan or per-node side-data in an array.

Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
2022-09-19 10:18:55 +09:30

212 lines
7.4 KiB
C

#ifndef LIGHTNING_COMMON_GOSSMAP_H
#define LIGHTNING_COMMON_GOSSMAP_H
#include "config.h"
#include <bitcoin/short_channel_id.h>
#include <ccan/take/take.h>
#include <ccan/typesafe_cb/typesafe_cb.h>
#include <common/amount.h>
#include <common/fp16.h>
struct node_id;
struct point32;
struct gossmap_node {
/* Offset in memory map for node_announce, or 0. */
u32 nann_off;
u32 num_chans;
u32 *chan_idxs;
};
struct gossmap_chan {
u32 cann_off;
u32 private: 1;
/* Technically redundant, but we have a hole anyway: from cann_off */
u32 plus_scid_off: 31;
/* Offsets of cupdates (0 if missing). Logically inside half_chan,
* but that would add padding. */
u32 cupdate_off[2];
/* two nodes we connect (lesser idx first) */
struct half_chan {
/* Top bit indicates it's enabled */
u32 enabled: 1;
u32 nodeidx : 31;
fp16_t htlc_min, htlc_max;
/* millisatoshi. */
u64 base_fee : 24;
/* millionths */
u64 proportional_fee : 20;
/* Delay for HTLC in blocks. */
u64 delay : 20;
} half[2];
};
/* If num_channel_updates_rejected is not NULL, indicates how many channels we
* marked inactive because their values were too high to be represented. */
struct gossmap *gossmap_load(const tal_t *ctx, const char *filename,
size_t *num_channel_updates_rejected);
/* Call this before using to ensure it's up-to-date. Returns true if something
* was updated. Note: this can scramble node and chan indexes! */
bool gossmap_refresh(struct gossmap *map, size_t *num_channel_updates_rejected);
/* Local modifications. */
struct gossmap_localmods *gossmap_localmods_new(const tal_t *ctx);
/* Create a local-only channel; if this conflicts with a real channel when added,
* that will be used instead.
* Returns false (and does nothing) if scid was already in localmods.
*/
bool gossmap_local_addchan(struct gossmap_localmods *localmods,
const struct node_id *n1,
const struct node_id *n2,
const struct short_channel_id *scid,
const u8 *features)
NON_NULL_ARGS(1,2,3,4);
/* Create a local-only channel_update: can apply to lcoal-only or
* normal channels. Returns false if amounts don't fit in our
* internal representation (implies channel unusable anyway). */
bool gossmap_local_updatechan(struct gossmap_localmods *localmods,
const struct short_channel_id *scid,
struct amount_msat htlc_min,
struct amount_msat htlc_max,
u32 base_fee,
u32 proportional_fee,
u16 delay,
bool enabled,
int dir)
NO_NULL_ARGS;
/* Apply localmods to this map */
void gossmap_apply_localmods(struct gossmap *map,
struct gossmap_localmods *localmods);
/* Remove localmods from this map */
void gossmap_remove_localmods(struct gossmap *map,
const struct gossmap_localmods *localmods);
/* Each channel has a unique (low) index. */
u32 gossmap_node_idx(const struct gossmap *map, const struct gossmap_node *node);
u32 gossmap_chan_idx(const struct gossmap *map, const struct gossmap_chan *chan);
struct gossmap_node *gossmap_node_byidx(const struct gossmap *map, u32 idx);
struct gossmap_chan *gossmap_chan_byidx(const struct gossmap *map, u32 idx);
/* Every node_idx/chan_idx will be < these.
* These values can change across calls to gossmap_check. */
u32 gossmap_max_node_idx(const struct gossmap *map);
u32 gossmap_max_chan_idx(const struct gossmap *map);
/* Find node with this node_id */
struct gossmap_node *gossmap_find_node(const struct gossmap *map,
const struct node_id *id);
/* Find chan with this short_channel_id */
struct gossmap_chan *gossmap_find_chan(const struct gossmap *map,
const struct short_channel_id *scid);
/* Get the short_channel_id of this chan */
struct short_channel_id gossmap_chan_scid(const struct gossmap *map,
const struct gossmap_chan *c);
/* Given a struct node, get the node_id */
void gossmap_node_get_id(const struct gossmap *map,
const struct gossmap_node *node,
struct node_id *id);
/* Do we have any values for this halfchannel ? */
static inline bool gossmap_chan_set(const struct gossmap_chan *chan, int dir)
{
return chan->cupdate_off[dir] != 0;
}
/* Return capacity if it's known (fails only on race condition, or a local mod) */
bool gossmap_chan_get_capacity(const struct gossmap *map,
const struct gossmap_chan *c,
struct amount_sat *amount);
/* Get the announcement msg which created this chan */
u8 *gossmap_chan_get_announce(const tal_t *ctx,
const struct gossmap *map,
const struct gossmap_chan *c);
/* Get the announcement msg (if any) for this node. */
u8 *gossmap_node_get_announce(const tal_t *ctx,
const struct gossmap *map,
const struct gossmap_node *n);
/* Return the feature bit (odd or even), or -1 if neither. */
int gossmap_chan_get_feature(const struct gossmap *map,
const struct gossmap_chan *c,
int fbit);
/* Return the feature bitmap */
u8 *gossmap_chan_get_features(const tal_t *ctx,
const struct gossmap *map,
const struct gossmap_chan *c);
/* Return the feature bit (odd or even), or -1 if neither (or no announcement) */
int gossmap_node_get_feature(const struct gossmap *map,
const struct gossmap_node *n,
int fbit);
/* Returns details from channel_update (must be gossmap_chan_set, and
* does not work for local_updatechan! */
void gossmap_chan_get_update_details(const struct gossmap *map,
const struct gossmap_chan *chan,
int dir,
u32 *timestamp,
u8 *message_flags,
u8 *channel_flags,
u32 *fee_base_msat,
u32 *fee_proportional_millionths,
struct amount_msat *htlc_minimum_msat,
/* iff message_flags & 1 */
struct amount_msat *htlc_maximum_msat);
/* Given a struct node, get the nth channel, and tell us if we're half[0/1].
* n must be less than node->num_chans */
struct gossmap_chan *gossmap_nth_chan(const struct gossmap *map,
const struct gossmap_node *node,
u32 n,
int *which_half);
/* Given a struct chan, get the nth node, where n is 0 or 1. */
struct gossmap_node *gossmap_nth_node(const struct gossmap *map,
const struct gossmap_chan *chan,
int n);
/* Can this channel send this amount? */
bool gossmap_chan_capacity(const struct gossmap_chan *chan,
int direction,
struct amount_msat amount);
/* Remove a channel from the map (warning! realloc can move gossmap_chan
* and gossmap_node ptrs!) */
void gossmap_remove_chan(struct gossmap *map, struct gossmap_chan *chan);
/* Remove node (by removing all its channels) */
void gossmap_remove_node(struct gossmap *map, struct gossmap_node *node);
/* Unsorted iterate through (do not add/remove channels or nodes!) */
size_t gossmap_num_nodes(const struct gossmap *map);
struct gossmap_node *gossmap_first_node(const struct gossmap *map);
struct gossmap_node *gossmap_next_node(const struct gossmap *map,
const struct gossmap_node *prev);
/* Unsorted iterate through (do not add/remove channels or nodes!) */
size_t gossmap_num_chans(const struct gossmap *map);
struct gossmap_chan *gossmap_first_chan(const struct gossmap *map);
struct gossmap_chan *gossmap_next_chan(const struct gossmap *map,
struct gossmap_chan *prev);
/* Each x-only pubkey has two possible values: we can figure out which by
* examining the gossmap. */
void gossmap_guess_node_id(const struct gossmap *map,
const struct point32 *point32,
struct node_id *id);
#endif /* LIGHTNING_COMMON_GOSSMAP_H */