feat: get latest blocks with only one sql query (#203)

With this PR we optimize the SQL query to get the lastest blocks and
with the transactions hash and type.

src/database.rs

@@ -1084,11 +1084,8 @@ impl Database {
 
     #[instrument(skip(self, block_id))]
     pub async fn block_by_id(&self, block_id: &[u8]) -> Result<Option<Row>, Error> {
-        // query for the block if it exists
-        let str = format!(
-            "SELECT * FROM {}.{BLOCKS_TABLE_NAME} WHERE block_id=$1",
-            self.network
-        );
+        let str = format!("SELECT b.*, txs FROM {0}.blocks b LEFT JOIN (SELECT block_id, JSON_AGG(JSON_BUILD_OBJECT('hash_id', encode(t.hash, 'hex'), 'tx_type', t.tx_type)) AS txs FROM {0}.transactions t GROUP BY t.block_id) t ON b.block_id = t.block_id WHERE b.block_id = $1;", self.network);
+
         query(&str)
             .bind(block_id)
             .fetch_optional(&*self.pool)
@@ -1099,12 +1096,10 @@ impl Database {
     /// Returns the block at `block_height` if present, otherwise returns an Error.
     #[instrument(skip(self))]
     pub async fn block_by_height(&self, block_height: u32) -> Result<Option<Row>, Error> {
-        let str = format!(
-            "SELECT * FROM {}.{BLOCKS_TABLE_NAME} WHERE header_height={block_height}",
-            self.network
-        );
+        let str = format!("SELECT b.*, txs FROM {0}.blocks b LEFT JOIN (SELECT block_id, JSON_AGG(JSON_BUILD_OBJECT('hash_id', encode(t.hash, 'hex'), 'tx_type', t.tx_type)) AS txs FROM {0}.transactions t GROUP BY t.block_id) t ON b.block_id = t.block_id WHERE b.header_height = $1;", self.network);
 
         query(&str)
+            .bind(block_height as i32)
             .fetch_optional(&*self.pool)
             .await
             .map_err(Error::from)
@@ -1113,7 +1108,7 @@ impl Database {
     #[instrument(skip(self))]
     /// Returns the latest block, otherwise returns an Error.
     pub async fn get_last_block(&self) -> Result<Row, Error> {
-        let str = format!("SELECT * FROM {0}.{BLOCKS_TABLE_NAME} WHERE header_height = (SELECT MAX(header_height) FROM {0}.{BLOCKS_TABLE_NAME})", self.network);
+        let str = format!("SELECT b.*, txs FROM {0}.blocks b LEFT JOIN (SELECT block_id, JSON_AGG(JSON_BUILD_OBJECT('hash_id', encode(t.hash, 'hex'), 'tx_type', t.tx_type)) AS txs FROM {0}.transactions t GROUP BY t.block_id) t ON b.block_id = t.block_id WHERE b.header_height = (SELECT MAX(header_height) FROM {0}.blocks);", self.network);
 
         // use query_one as the row matching max height is unique.
         query(&str)
@@ -1406,7 +1401,7 @@ impl Database {
         num: &i32,
         offset: Option<&i32>,
     ) -> Result<Vec<Row>, Error> {
-        let str = format!("SELECT * FROM {0}.{BLOCKS_TABLE_NAME} ORDER BY header_height DESC LIMIT {1} OFFSET {2};", self.network, num, offset.unwrap_or(&  0));
+        let str = format!("SELECT b.*, t.txs FROM {0}.blocks b LEFT JOIN (SELECT block_id, JSON_AGG(JSON_BUILD_OBJECT('hash_id', encode(t.hash, 'hex'), 'tx_type', t.tx_type)) AS txs FROM {0}.transactions t GROUP BY t.block_id) t ON b.block_id = t.block_id ORDER BY b.header_height DESC LIMIT {1} OFFSET {2};", self.network, num, offset.unwrap_or(&  0));
 
         // use query_one as the row matching max height is unique.
         query(&str)

src/server/blocks.rs

@@ -220,6 +220,14 @@ impl TryFrom<&Row> for BlockInfo {
 
         let last_commit = LastCommitInfo::read_from(row)?;
 
+        // tx hashes
+        let txs: Option<serde_json::Value> = row.try_get("txs")?;
+        let tx_hashes: Vec<TxShort> = if let Some(txs) = txs {
+            serde_json::from_value(txs)?
+        } else {
+            vec![]
+        };
+
         let header = Header {
             version,
             chain_id,
@@ -241,7 +249,7 @@ impl TryFrom<&Row> for BlockInfo {
             block_id: HashID(block_id),
             header,
             last_commit,
-            tx_hashes: vec![],
+            tx_hashes,
         })
     }
 }

src/server/endpoints/block.rs

@@ -3,14 +3,10 @@ use axum::{
     Json,
 };
 use serde::{Deserialize, Serialize};
-use sqlx::Row as TRow;
 use std::collections::HashMap;
 use tracing::info;
 
-use crate::{
-    server::{blocks::HashID, blocks::TxShort, ServerState},
-    BlockInfo, Error,
-};
+use crate::{server::ServerState, BlockInfo, Error};
 
 #[derive(Debug, Serialize, Deserialize, PartialEq)]
 #[serde(untagged)]
@@ -24,25 +20,6 @@ pub struct LatestBlocks {
     pub blocks: Vec<BlockInfo>,
 }
 
-async fn get_tx_hashes(
-    state: &ServerState,
-    block: &mut BlockInfo,
-    hash: &[u8],
-) -> Result<(), Error> {
-    let rows = state.db.get_tx_hashes_block(hash).await?;
-
-    let mut tx_hashes: Vec<TxShort> = vec![];
-    for row in rows.iter() {
-        let hash_id = HashID(row.try_get("hash")?);
-        let tx_type: String = row.try_get("tx_type")?;
-        tx_hashes.push(TxShort { tx_type, hash_id });
-    }
-
-    block.tx_hashes = tx_hashes;
-
-    Ok(())
-}
-
 pub async fn get_block_by_hash(
     State(state): State<ServerState>,
     Path(hash): Path<String>,
@@ -55,10 +32,7 @@ pub async fn get_block_by_hash(
     let Some(row) = row else {
         return Ok(Json(None));
     };
-    let mut block = BlockInfo::try_from(&row)?;
-
-    let block_id: Vec<u8> = row.try_get("block_id")?;
-    get_tx_hashes(&state, &mut block, &block_id).await?;
+    let block = BlockInfo::try_from(&row)?;
 
     Ok(Json(Some(block)))
 }
@@ -74,10 +48,7 @@ pub async fn get_block_by_height(
         return Ok(Json(None));
     };
 
-    let mut block = BlockInfo::try_from(&row)?;
-
-    let block_id: Vec<u8> = row.try_get("block_id")?;
-    get_tx_hashes(&state, &mut block, &block_id).await?;
+    let block = BlockInfo::try_from(&row)?;
 
     Ok(Json(Some(block)))
 }
@@ -96,10 +67,7 @@ pub async fn get_last_block(
         let mut blocks: LatestBlocks = LatestBlocks { blocks: vec![] };
 
         for row in rows {
-            let mut block = BlockInfo::try_from(&row)?;
-
-            let block_id: Vec<u8> = row.try_get("block_id")?;
-            get_tx_hashes(&state, &mut block, &block_id).await?;
+            let block = BlockInfo::try_from(&row)?;
 
             blocks.blocks.push(block);
         }
@@ -108,10 +76,7 @@ pub async fn get_last_block(
     } else {
         let row = state.db.get_last_block().await?;
 
-        let mut block = BlockInfo::try_from(&row)?;
-
-        let block_id: Vec<u8> = row.try_get("block_id")?;
-        get_tx_hashes(&state, &mut block, &block_id).await?;
+        let block = BlockInfo::try_from(&row)?;
 
         Ok(Json(LatestBlock::LastBlock(Box::new(block))))
     }