Commit Graph

8 Commits

Author SHA1 Message Date
Rusty Russell
eb370ab8ff gossmap: remembers when a channel is private.
Steals one bit from the scid_off, and turns that into a relative
offset.

Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
2021-05-22 17:53:04 +09:30
Rusty Russell
c5bd518d2f gossmap: change local API.
Now we create a separate set of local mods, and apply and unapply it.
This is more efficient than the previous approach, since we can do
some work up-front.  It's also more graceful (and well-defined) when a
local modification overlaps an existing one.

Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
2021-02-04 12:02:36 +10:30
Rusty Russell
1490ae4cf6 common: support transitory local map additions to gossmap.
This will let us add routehints to the map and use dijkstra etc like
normal.

Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
2021-02-04 12:02:36 +10:30
Rusty Russell
cc4ea9420a common: extract fp16 routines into their own file.
We might want to use them elsewhere.

Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
2021-02-04 12:02:36 +10:30
Rusty Russell
2734fd274e gossmap: helper to try to map x-only nodeid into 33-byte pubkey id.
This is a bridge for offers which use x-only pubkeys, and the current
code which doesn't.

Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
2020-12-09 16:40:13 +10:30
Rusty Russell
cd5a93d0bd gossmap: fix reutrn of gossmap_xxx_has_feature, rename.
1. One place returned false instead of -1.
2. The names implied it returned a bool, and it doesn't.

Fix both, and curse C's loose typing a little.

Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
2020-10-28 15:32:12 +10:30
Rusty Russell
b80342b928 gossmap: implement feature tests
Faster than pulling the announce msg and parsing.  We need this to test
if the node supports TLV.

Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
2020-10-21 08:58:34 +10:30
Rusty Russell
daba3e7deb common/gossmap: helper to map the gossip store.
I went overboard on optimization.  I am so sorry:
1. Squeezed channel min/max into 16 bits.
2. Uses mmap and leaves node_ids in the file.
3. Uses offsets instead of pointers where possible.
4. Uses custom free-list to allocate inside arrays.
5. Ignores our autogenerated marshalling code in favor of direct derefs.
6. Carefully aligns everything so we use minimal ram.

The result is that the current gossip_store:
 - load time (-O3 -flto laptop): 40msec
 - load time (-g laptop i.e. DEVELOPER=0): 60msec
 - load time (-O0 laptop i.e. DEVELOPER=1): 110msec
 - Total memory: 2.6MB:
   - 1.5MB for the array of channels
   - 512k for the channel htable to map scid -> channel.
   - 320k for the node htable to map nodeid -> node.
   - 192k for the array of channels inside each node
   - 94k for the array of nodes

Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
2020-08-28 10:56:50 +09:30