Availability store subsystem (paritytech#1404)

* Initial commit

* WIP

* Make atomic transactions

* Remove pruning code

* Fix build and add a Nop to bridge

* Fixes from review

* Move config struct around for clarity

* Rename constructor and warn on missing docs

* Fix a test and rename a message

* Fix some more reviews

* Obviously failed to rebase cleanly

Cargo.toml

@@ -45,6 +45,7 @@ members = [
 
 	"node/core/bitfield-signing",
 	"node/core/proposer",
+	"node/core/av-store",
 	"node/network/bridge",
 	"node/network/pov-distribution",
 	"node/network/statement-distribution",

node/core/av-store/Cargo.toml

@@ -0,0 +1,24 @@
+[package]
+name = "polkadot-node-core-av-store"
+version = "0.1.0"
+authors = ["Parity Technologies <[email protected]>"]
+edition = "2018"
+
+[dependencies]
+futures = "0.3.5"
+polkadot-subsystem = { package = "polkadot-node-subsystem", path = "../../subsystem" }
+polkadot-overseer = { path = "../../overseer" }
+polkadot-primitives = { path = "../../../primitives" }
+erasure = { package = "polkadot-erasure-coding", path = "../../../erasure-coding" }
+kvdb = "0.7.0"
+kvdb-rocksdb = "0.9.0"
+codec = { package = "parity-scale-codec", version = "1.3.1", features = ["derive"] }
+log = "0.4.8"
+derive_more = "0.99.9"
+
+[dev-dependencies]
+sp-core = { git = "https://github.com/paritytech/substrate", branch = "master" }
+futures = { version = "0.3.5", features = ["thread-pool"] }
+polkadot-subsystem = { package = "polkadot-node-subsystem", path = "../../subsystem", features = [ "test-helpers" ] }
+kvdb-memorydb = "0.7.0"
+assert_matches = "1.3.0"