db/block: add turnover metric

Defined as the sum of all outputs of all
transactions. Using the sum across all
outputs instead of across all inputs is
not mere convenience due to the amount
being available there, but we also want
to capture the subsidy in this number.

Author: dspicher

migrations/2023-08-09-202146_add_opreturn_table/up.sql

@@ -6,5 +6,6 @@ CREATE TABLE blocks (
     nonce BIGINT NOT NULL,
     tx_count INTEGER NOT NULL,
     size INTEGER NOT NULL,
-    weight BIGINT NOT NULL
+    weight BIGINT NOT NULL,
+    turnover BIGINT NOT NULL
 );

src/db/mod.rs

@@ -21,6 +21,7 @@ pub struct Block {
     pub tx_count: i32,
     pub size: i32,
     pub weight: i64,
+    pub turnover: i64,
 }
 
 const MIGRATIONS: diesel_migrations::EmbeddedMigrations = diesel_migrations::embed_migrations!();

src/db/schema.rs

@@ -10,5 +10,6 @@ diesel::table! {
         tx_count -> Integer,
         size -> Integer,
         weight -> BigInt,
+        turnover -> BigInt,
     }
 }

src/parser/mod.rs

@@ -59,6 +59,12 @@ impl BlockchainParser {
             Self::on_header(&header, self.cur_height);
             let block = self.chain_storage.get_block(self.cur_height).unwrap();
 
+            let turnover: u64 = block
+                .txdata
+                .iter()
+                .flat_map(|tx| tx.output.iter().map(|output| output.value))
+                .sum();
+
             tracing::trace!(target: "parser", "on_block(height={}) called", self.cur_height);
             blocks.push(crate::db::Block {
                 height: self.cur_height.try_into()?,
@@ -69,6 +75,7 @@ impl BlockchainParser {
                 tx_count: block.txdata.len().try_into()?,
                 size: block.size().try_into()?,
                 weight: block.weight().to_wu().try_into()?,
+                turnover: turnover.try_into()?,
             });
             if blocks.len() == block_buffer_size {
                 self.db.insert_blocks(blocks)?;

tests/bitcoin.rs

@@ -121,4 +121,12 @@ fn test_blocks_db() {
     let mut parser = parser();
     parser.start().unwrap();
     assert_eq!(parser.db().blocks_count().unwrap(), 171);
+    assert_eq!(
+        u64::try_from(parser.db().block(100).unwrap().turnover).unwrap(),
+        50 * bitcoin::Amount::ONE_BTC.to_sat()
+    );
+    assert_eq!(
+        u64::try_from(parser.db().block(170).unwrap().turnover).unwrap(),
+        100 * bitcoin::Amount::ONE_BTC.to_sat()
+    );
 }