sqldb/sqlc: add graph channel schemas

In this commit, we define the SQL schemas for storing graph channel
data. This includes a new `channels` table and a new `channel_features`
table along with various indices.

Author: ellemouton

sqldb/sqlc/migrations/000007_graph.down.sql

@@ -4,10 +4,19 @@ DROP INDEX IF EXISTS node_extra_types_unique;
 DROP INDEX IF EXISTS node_features_unique;
 DROP INDEX IF EXISTS node_addresses_unique;
 DROP INDEX IF EXISTS source_nodes_unique;
+DROP INDEX IF EXISTS channels_node_id_1_idx;
+DROP INDEX IF EXISTS channels_node_id_2_idx;
+DROP INDEX IF EXISTS channels_unique;
+DROP INDEX IF EXISTS channels_version_outpoint_idx;
+DROP INDEX IF EXISTS channel_features_unique;
+DROP INDEX IF EXISTS channel_extra_types_unique;
 
 -- Drop tables in order of reverse dependencies.
 DROP TABLE IF EXISTS source_nodes;
 DROP TABLE IF EXISTS node_addresses;
 DROP TABLE IF EXISTS node_features;
 DROP TABLE IF EXISTS node_extra_types;
-DROP TABLE IF EXISTS nodes;
+DROP TABLE IF EXISTS nodes;
+DROP TABLE IF EXISTS channels;
+DROP TABLE IF EXISTS channel_features;
+DROP TABLE IF EXISTS channel_extra_types;

sqldb/sqlc/migrations/000007_graph.up.sql

@@ -94,4 +94,117 @@ CREATE TABLE IF NOT EXISTS source_nodes (
 );
 CREATE UNIQUE INDEX IF NOT EXISTS source_nodes_unique ON source_nodes (
     node_id
-);
+);
+
+/* ─────────────────────────────────────────────
+   channel data tables
+   ─────────────────────────────────────────────
+*/
+
+-- channels stores all teh channels that we are aware of in the graph.
+CREATE TABLE IF NOT EXISTS channels (
+    -- The db ID of the channel.
+    id INTEGER PRIMARY KEY,
+
+    -- The protocol version that this node was gossiped on.
+    version SMALLINT NOT NULL,
+
+    -- The channel id (short channel id) of the channel.
+    scid BLOB NOT NULL,
+
+    -- A reference to a node in the nodes table for the node_1 node in
+    -- the channel announcement.
+    node_id_1 BIGINT NOT NULL REFERENCES nodes(id) ON DELETE CASCADE,
+
+    -- A reference to a node in the nodes table for the node_2 node in
+    -- the channel announcement.
+    node_id_2 BIGINT NOT NULL REFERENCES nodes(id) ON DELETE CASCADE,
+
+    -- The outpoint of the funding transaction. We chose to store this
+    -- in a string format for the sake of readability and user queries on
+    -- outpoint.
+    outpoint TEXT NOT NULL,
+
+    -- The capacity of the channel in millisatoshis. This is nullable since
+    -- (for the v1 protocol at least), the capacity is not necessarily known as
+    -- it is not gossiped in the channel announcement.
+    capacity BIGINT,
+
+    -- bitcoin_key_1 is the public key owned by node_1 that is used to create
+    -- a funding transaction. It is nullable since future protocol version may
+    -- not make use of this field.
+    bitcoin_key_1 BLOB,
+
+    -- bitcoin_key_2 is the public key owned by node_2 that is used to create
+    -- the funding transaction. It is nullable since future protocol version may
+    -- not make use of this field.
+    bitcoin_key_2 BLOB,
+
+    -- node_1_signature is the signature of the serialised channel announcement
+    -- using the node_1 public key. It is nullable since future protocol
+    -- versions may not make use of this field _and_ because for this node's own
+    -- channels, the signature will only be known after the initial record
+    -- creation.
+    node_1_signature BLOB,
+
+    -- node_2_signature is the signature of the serialised channel announcement
+    -- using the node_2 public key. It is nullable since future protocol
+    -- versions may not make use of this field _and_ because for this node's own
+    -- channels, the signature will only be known after the initial record
+    -- creation.
+    node_2_signature BLOB,
+
+    -- bitcoin_1_signature is the signature of the serialised channel
+    -- announcement using bitcion_key_1. It is nullable since future protocol
+    -- versions may not make use of this field _and_ because for this node's
+    -- own channels, the signature will only be known after the initial record
+    -- creation.
+    bitcoin_1_signature BLOB,
+
+    -- bitcoin_2_signature is the signature of the serialised channel
+    -- announcement using bitcion_key_2. It is nullable since future protocol
+    -- versions may not make use of this field _and_ because for this node's
+    -- own channels, the signature will only be known after the initial record
+    -- creation.
+    bitcoin_2_signature BLOB
+);
+-- We'll want to lookup all the channels owned by a node, so we create
+-- indexes on the node_id_1 and node_id_2 columns.
+CREATE INDEX IF NOT EXISTS channels_node_id_1_idx ON channels(node_id_1);
+CREATE INDEX IF NOT EXISTS channels_node_id_2_idx ON channels(node_id_2);
+
+-- A channel (identified by a short channel id) can only have one active
+-- channel announcement per protocol version. We also order the index by
+-- scid in descending order so that we have an idea of the latest channel
+-- announcement we know of.
+CREATE UNIQUE INDEX IF NOT EXISTS channels_unique ON channels(version, scid DESC);
+CREATE INDEX IF NOT EXISTS channels_version_outpoint_idx ON channels(version, outpoint);
+
+-- channel_features contains the feature bits of a channel.
+CREATE TABLE IF NOT EXISTS channel_features (
+    -- The channel id this feature belongs to.
+    channel_id BIGINT NOT NULL REFERENCES channels(id) ON DELETE CASCADE,
+
+    -- The feature bit value.
+    feature_bit INTEGER NOT NULL
+);
+CREATE UNIQUE INDEX IF NOT EXISTS channel_features_unique ON channel_features (
+    channel_id, feature_bit
+);
+
+-- channel_extra_types stores any extra TLV fields covered by a channels
+-- announcement that we do not have an explicit column for in the channels
+-- table.
+CREATE TABLE IF NOT EXISTS channel_extra_types (
+    -- The channel id this TLV field belongs to.
+    channel_id BIGINT NOT NULL REFERENCES channels(id) ON DELETE CASCADE,
+
+    -- The Type field.
+    type BIGINT NOT NULL,
+
+    -- The value field.
+    value BLOB
+);
+CREATE UNIQUE INDEX IF NOT EXISTS channel_extra_types_unique ON channel_extra_types (
+    type, channel_id
+);