topo: Remove in-memory txs from the block struct

The only use for these was to compute their txids so we could notify depth
in case of reorgs.

Signed-off-by: Christian Decker <decker.christian@gmail.com>

lightningd/chaintopology.c

@@ -28,18 +28,6 @@ static void next_topology_timer(struct chain_topology *topo)
 			     try_extend_tip, topo));
 }
 
-/* FIXME: Remove tx from block when peer done. */
-static void add_tx_to_block(struct block *b,
-			    const struct bitcoin_tx *tx, const u32 txnum)
-{
-	size_t n = tal_count(b->txs);
-
-	tal_resize(&b->txs, n+1);
-	tal_resize(&b->txnums, n+1);
-	b->txs[n] = tal_steal(b->txs, tx);
-	b->txnums[n] = txnum;
-}
-
 static bool we_broadcast(const struct chain_topology *topo,
 			 const struct bitcoin_txid *txid)
 {
@@ -86,7 +74,6 @@ static void filter_block_txs(struct chain_topology *topo, struct block *b)
 		bitcoin_txid(tx, &txid);
 		if (watching_txid(topo, &txid) || we_broadcast(topo, &txid) ||
 		    satoshi_owned != 0) {
-			add_tx_to_block(b, tx, i);
 			wallet_transaction_add(topo->wallet, tx, b->height, i);
 		}
 	}
@@ -442,7 +429,6 @@ static struct block *new_block(struct chain_topology *topo,
 
 	b->hdr = blk->hdr;
 
-	b->txs = tal_arr(b, const struct bitcoin_tx *, 0);
 	b->txnums = tal_arr(b, u32, 0);
 	b->full_txs = tal_steal(b, blk->tx);
 
@@ -452,7 +438,8 @@ static struct block *new_block(struct chain_topology *topo,
 static void remove_tip(struct chain_topology *topo)
 {
 	struct block *b = topo->tip;
-	size_t i, n = tal_count(b->txs);
+	struct bitcoin_txid *txs;
+	size_t i, n;
 
 	/* Move tip back one. */
 	topo->tip = b->prev;
@@ -461,9 +448,12 @@ static void remove_tip(struct chain_topology *topo)
 		      b->height,
 		      type_to_string(tmpctx, struct bitcoin_blkid, &b->blkid));
 
+	txs = wallet_transactions_by_height(b, topo->wallet, b->height);
+	n = tal_count(txs);
+
 	/* Notify that txs are kicked out. */
 	for (i = 0; i < n; i++)
-		txwatch_fire(topo, b->txs[i], 0);
+		txwatch_fire(topo, &txs[i], 0);
 
 	wallet_block_remove(topo->wallet, b);
 	block_map_del(&topo->block_map, b);

lightningd/chaintopology.h

@@ -49,9 +49,6 @@ struct block {
 	/* Key for hash table */
 	struct bitcoin_blkid blkid;
 
-	/* Transactions in this block we care about */
-	const struct bitcoin_tx **txs;
-
 	/* And their associated index in the block */
 	u32 *txnums;
 

lightningd/watch.c

@@ -229,17 +229,15 @@ static bool txw_fire(struct txwatch *txw,
 }
 
 void txwatch_fire(struct chain_topology *topo,
-		  const struct bitcoin_tx *tx,
+		  const struct bitcoin_txid *txid,
 		  unsigned int depth)
 {
-	struct bitcoin_txid txid;
 	struct txwatch *txw;
 
-	bitcoin_txid(tx, &txid);
+	txw = txwatch_hash_get(&topo->txwatches, txid);
-	txw = txwatch_hash_get(&topo->txwatches, &txid);
 
 	if (txw)
-		txw_fire(txw, &txid, depth);
+		txw_fire(txw, txid, depth);
 }
 
 void txowatch_fire(const struct txowatch *txow,

lightningd/watch.h

@@ -70,7 +70,7 @@ struct txwatch *find_txwatch(struct chain_topology *topo,
 			     const struct channel *channel);
 
 void txwatch_fire(struct chain_topology *topo,
-		  const struct bitcoin_tx *tx,
+		  const struct bitcoin_txid *txid,
 		  unsigned int depth);
 
 void txowatch_fire(const struct txowatch *txow,

wallet/wallet.c

@@ -2246,3 +2246,25 @@ fail:
 	sqlite3_finalize(stmt);
 	return NULL;
 }
+
+struct bitcoin_txid *wallet_transactions_by_height(const tal_t *ctx,
+						   struct wallet *w,
+						   const u32 blockheight)
+{
+	sqlite3_stmt *stmt;
+	struct bitcoin_txid *txids = tal_arr(ctx, struct bitcoin_txid, 0);
+	int count = 0;
+	stmt = db_prepare(
+	    w->db, "SELECT id FROM transactions WHERE blockheight=?");
+	sqlite3_bind_int(stmt, 1, blockheight);
+
+	while (sqlite3_step(stmt) == SQLITE_ROW) {
+		count++;
+		tal_resize(&txids, count);
+		sqlite3_column_sha256(stmt, 0, &txids[count-1].shad.sha);
+	}
+	sqlite3_finalize(stmt);
+
+	return txids;
+}
+

wallet/wallet.h

@@ -827,4 +827,11 @@ u32 wallet_transaction_height(struct wallet *w, const struct bitcoin_txid *txid)
 struct txlocator *wallet_transaction_locate(const tal_t *ctx, struct wallet *w,
 					    const struct bitcoin_txid *txid);
 
+/**
+ * Get transaction IDs for transactions that we are tracking.
+ */
+struct bitcoin_txid *wallet_transactions_by_height(const tal_t *ctx,
+						   struct wallet *w,
+						   const u32 blockheight);
+
 #endif /* LIGHTNING_WALLET_WALLET_H */