Optional chain Bitswap

[magik6k]

A bit messy because there's a circular dep between chainblockstore/bitswap and another one between bitswap/network/chainstore, but running this on my node I'm not seeing any warnings coming from this, which is expected.

[magik6k]

Just verified to work on a node synced from a snapshot which reproduced the sync issue. It generated those logs:

2020-11-03T23:38:03.002+0100	ERROR	blockstore	blockstore/fallbackstore.go:33	fallbackstore: Block not found locally, fetching from the network	{"cid": "bafy2bzacebctjyglcymp3afqwfxqugxkebwcar2h5kppvvyquixgk6mu52uvy"}
2020-11-03T23:38:03.002+0100	INFO	bs:sess	session/session.go:459	No peers - broadcasting	{"session": 4, "want-count": 1}
2020-11-03T23:38:03.009+0100	INFO	sub	sub/incoming.go:98	new block over pubsub	{"cid": "bafy2bzacebazcxhqrmymhxhxksazwxuak6xtnc4jhjpqkqr4q33oyxnb42c6i", "source": "12D3KooWPGWzrJCHsFGNmMyNE659FWkofCo6t94k87dGXXynmWgX", "msgfetch": 0.002336539}
2020-11-03T23:38:03.032+0100	ERROR	blockstore	blockstore/fallbackstore.go:33	fallbackstore: Block not found locally, fetching from the network	{"cid": "bafy2bzacebvdyql6nyrgakhmquiovflqvvtcu2jzihq3o4x2kbkwcoa4ehxfg"}
2020-11-03T23:38:03.033+0100	INFO	bs:sess	session/session.go:459	No peers - broadcasting	{"session": 5, "want-count": 1}
2020-11-03T23:38:03.091+0100	ERROR	blockstore	blockstore/fallbackstore.go:33	fallbackstore: Block not found locally, fetching from the network	{"cid": "bafy2bzacebd7svs7jx5vuvukz56dulpi5smk46jeqdjtomzkidta2tbv77we4"}
2020-11-03T23:38:03.091+0100	INFO	bs:sess	session/session.go:459	No peers - broadcasting	{"session": 6, "want-count": 1}
2020-11-03T23:38:03.151+0100	ERROR	blockstore	blockstore/fallbackstore.go:33	fallbackstore: Block not found locally, fetching from the network	{"cid": "bafy2bzacec264zetfptfx6rtlwiuuwzc7qf4n2lxginnpvaje37fwhpqx74hw"}
2020-11-03T23:38:03.151+0100	INFO	bs:sess	session/session.go:459	No peers - broadcasting	{"session": 7, "want-count": 1}
2020-11-03T23:38:03.212+0100	ERROR	blockstore	blockstore/fallbackstore.go:33	fallbackstore: Block not found locally, fetching from the network	{"cid": "bafy2bzaceb4xnbx4sg7xh35u46gz4u6me2niqoxgvof5jzs6dp2ynj3fhqfpe"}
2020-11-03T23:38:03.212+0100	INFO	bs:sess	session/session.go:459	No peers - broadcasting	{"session": 8, "want-count": 1}
2020-11-03T23:38:03.244+0100	ERROR	blockstore	blockstore/fallbackstore.go:33	fallbackstore: Block not found locally, fetching from the network	{"cid": "bafy2bzaced7h7oanldkbhy3ju6wxvesni2kyulcg3t6a6ddep4xtfjxk5arto"}
2020-11-03T23:38:03.244+0100	INFO	bs:sess	session/session.go:459	No peers - broadcasting	{"session": 9, "want-count": 1}
2020-11-03T23:38:03.275+0100	ERROR	blockstore	blockstore/fallbackstore.go:33	fallbackstore: Block not found locally, fetching from the network	{"cid": "bafy2bzacedj3o6b6ytcdnult2nokvy7fymm2muvw2dhsxp2ans33rnr4udooa"}

and then just worked