wallet: Implement channel_config persistence

lightningd/channel_config.h

@@ -32,6 +32,8 @@
  *    * [`2`:`max_accepted_htlcs`]
  */
 struct channel_config {
+	/* Database ID */
+	u64 id;
 	u64 dust_limit_satoshis;
 	u64 max_htlc_value_in_flight_msat;
 	u64 channel_reserve_satoshis;

wallet/db.c

@@ -80,6 +80,16 @@ char *dbmigrations[] = {
     "  address TEXT,"
     "  PRIMARY KEY (id)"
     ");",
+    "CREATE TABLE channel_configs ("
+    "  id INTEGER,"
+    "  dust_limit_satoshis INTEGER,"
+    "  max_htlc_value_in_flight_msat INTEGER,"
+    "  channel_reserve_satoshis INTEGER,"
+    "  htlc_minimum_msat INTEGER,"
+    "  to_self_delay INTEGER,"
+    "  max_accepted_htlcs INTEGER,"
+    "  PRIMARY KEY (id)"
+    ");",
     NULL,
 };
 

wallet/wallet.c

@@ -558,6 +558,58 @@ static char* db_serialize_pubkey(const tal_t *ctx, struct pubkey *pk)
 	return tal_hex(ctx, der);
 }
 
+bool wallet_channel_config_save(struct wallet *w, struct channel_config *cc)
+{
+	bool ok = true;
+	/* Is this an update? If not insert a stub first */
+	if (!cc->id) {
+		ok &= db_exec(__func__, w->db,
+			      "INSERT INTO channel_configs DEFAULT VALUES;");
+		cc->id = sqlite3_last_insert_rowid(w->db->sql);
+	}
+
+	ok &= db_exec(
+	    __func__, w->db, "UPDATE channel_configs SET"
+			     "  dust_limit_satoshis=%" PRIu64 ","
+			     "  max_htlc_value_in_flight_msat=%" PRIu64 ","
+			     "  channel_reserve_satoshis=%" PRIu64 ","
+			     "  htlc_minimum_msat=%" PRIu64 ","
+			     "  to_self_delay=%d,"
+			     "  max_accepted_htlcs=%d"
+			     " WHERE id=%" PRIu64 ";",
+	    cc->dust_limit_satoshis, cc->max_htlc_value_in_flight_msat,
+	    cc->channel_reserve_satoshis, cc->htlc_minimum_msat,
+	    cc->to_self_delay, cc->max_accepted_htlcs, cc->id);
+
+	return ok;
+}
+
+bool wallet_channel_config_load(struct wallet *w, const u64 id,
+				struct channel_config *cc)
+{
+	bool ok = true;
+	int col = 1;
+	const char *query =
+	    "SELECT id, dust_limit_satoshis, max_htlc_value_in_flight_msat, "
+	    "channel_reserve_satoshis, htlc_minimum_msat, to_self_delay, "
+	    "max_accepted_htlcs FROM channel_configs WHERE id=%" PRIu64 ";";
+	sqlite3_stmt *stmt = db_query(__func__, w->db, query, id);
+	if (!stmt || sqlite3_step(stmt) != SQLITE_ROW) {
+		sqlite3_finalize(stmt);
+		return false;
+	}
+	cc->id = id;
+	cc->dust_limit_satoshis = sqlite3_column_int64(stmt, col++);
+	cc->max_htlc_value_in_flight_msat = sqlite3_column_int64(stmt, col++);
+	cc->channel_reserve_satoshis = sqlite3_column_int64(stmt, col++);
+	cc->htlc_minimum_msat = sqlite3_column_int64(stmt, col++);
+	cc->to_self_delay = sqlite3_column_int(stmt, col++);
+	cc->max_accepted_htlcs = sqlite3_column_int(stmt, col++);
+	assert(col == 7);
+	sqlite3_finalize(stmt);
+	return ok;
+}
+
 bool wallet_channel_save(struct wallet *w, struct wallet_channel *chan){
 	bool ok = true;
 	struct peer *p = chan->peer;

wallet/wallet.h

@@ -5,6 +5,7 @@
 #include "db.h"
 #include <ccan/crypto/shachain/shachain.h>
 #include <ccan/tal/tal.h>
+#include <lightningd/channel_config.h>
 #include <lightningd/utxo.h>
 #include <wally_bip32.h>
 
@@ -173,4 +174,15 @@ bool wallet_channel_load(struct wallet *w, const u64 id,
  *   insert)
  */
 bool wallet_channel_save(struct wallet *w, struct wallet_channel *chan);
+
+/**
+ * wallet_channel_config_save -- Upsert a channel_config into the database
+ */
+bool wallet_channel_config_save(struct wallet *w, struct channel_config *cc);
+
+/**
+ * wallet_channel_config_load -- Load channel_config from database into cc
+ */
+bool wallet_channel_config_load(struct wallet *w, const u64 id,
+				struct channel_config *cc);
 #endif /* WALLET_WALLET_H */