Reject requests for blocks before subgraph minimum

Author: Theodus

src/main.rs

@@ -519,6 +519,9 @@ async fn handle_subgraph_query_inner(
                 QueryEngineError::FeesTooHigh(count) => {
                     format!("No suitable indexer found, {} indexers requesting higher fees for this query", count)
                 }
+                QueryEngineError::BlockBeforeMin => {
+                    "Requested block before minimum `startBlock` of subgraph manifest".into()
+                }
                 QueryEngineError::MissingBlock(_) => {
                     "Gateway failed to resolve required blocks".into()
                 }

src/manifest_client.rs

@@ -11,6 +11,7 @@ pub struct SubgraphInfo {
     pub deployment: SubgraphDeploymentID,
     pub network: String,
     pub features: Vec<String>,
+    pub min_block: u64,
 }
 
 pub type SubgraphInfoMap =
@@ -74,21 +75,31 @@ pub async fn fetch_manifest(
         .map_err(|err| (deployment, err.to_string()))?;
     let manifest = serde_yaml::from_str::<SubgraphManifest>(&payload)
         .map_err(|err| (deployment, err.to_string()))?;
+    let min_block = manifest
+        .data_sources
+        .iter()
+        .map(|data_source| data_source.source.start_block.unwrap_or(0))
+        .min()
+        .unwrap_or(0);
     // We are assuming that all `dataSource.network` fields are identical.
     // This is guaranteed for now.
     let network = manifest
         .data_sources
         .into_iter()
-        .filter_map(|data_source| data_source.network)
+        .map(|data_source| data_source.network)
         .next()
         .ok_or_else(|| (deployment, "Network not found".to_string()))?;
     Ok(SubgraphInfo {
         deployment,
         network,
+        min_block,
         features: manifest.features,
     })
 }
 
+// Subgraph manifest schema:
+// https://github.com/graphprotocol/graph-node/blob/master/docs/subgraph-manifest.md
+
 #[derive(Deserialize)]
 #[serde(rename_all = "camelCase")]
 pub struct SubgraphManifest {
@@ -98,6 +109,14 @@ pub struct SubgraphManifest {
 }
 
 #[derive(Deserialize)]
+#[serde(rename_all = "camelCase")]
 pub struct DataSource {
-    pub network: Option<String>,
+    pub network: String,
+    pub source: EthereumContractSource,
+}
+
+#[derive(Deserialize)]
+#[serde(rename_all = "camelCase")]
+pub struct EthereumContractSource {
+    pub start_block: Option<u64>,
 }

src/query_engine/mod.rs

@@ -120,6 +120,7 @@ pub enum QueryEngineError {
     NoIndexerSelected,
     FeesTooHigh(usize),
     MalformedQuery,
+    BlockBeforeMin,
     MissingBlock(UnresolvedBlock),
 }
 
@@ -276,6 +277,12 @@ where
         let freshness_requirements =
             Indexers::freshness_requirements(&mut context, block_resolver).await?;
 
+        // Reject queries for blocks before minimum start block of subgraph manifest.
+        match freshness_requirements.minimum_block {
+            Some(min_block) if min_block < subgraph.min_block => return Err(BlockBeforeMin),
+            _ => (),
+        };
+
         for retry_count in 0..self.config.indexer_selection_retry_limit {
             let selection_timer = with_metric(
                 &METRICS.indexer_selection_duration,

src/query_engine/tests.rs

@@ -169,6 +169,7 @@ impl Topology {
         query.subgraph = Some(Ptr::new(SubgraphInfo {
             deployment: deployment.id,
             network: deployment.network,
+            min_block: 0,
             features: vec![],
         }));
         query