core,graph,runtime: Avoid creating duplicate runtime hosts, log warning

fordN · fordN · commit 1c634cc1e07f · 2020-09-29T12:30:00.000-07:00
diff --git a/core/src/subgraph/instance.rs b/core/src/subgraph/instance.rs
@@ -272,7 +272,7 @@ where
         data_source: DataSource,
         top_level_templates: Arc<Vec<DataSourceTemplate>>,
         metrics: Arc<HostMetrics>,
-    ) -> Result<Arc<T::Host>, anyhow::Error> {
+    ) -> Result<Option<Arc<T::Host>>, anyhow::Error> {
         // Protect against creating more than the allowed maximum number of data sources
         if let Some(max_data_sources) = *MAX_DATA_SOURCES {
             if self.hosts.len() >= max_data_sources {
@@ -289,7 +289,12 @@ where
             top_level_templates,
             metrics.clone(),
         )?);
-        self.hosts.push(host.clone());
-        Ok(host)
+
+        Ok(if self.hosts.contains(&host) {
+            None
+        } else {
+            self.hosts.push(host.clone());
+            Some(host)
+        })
     }
 }
diff --git a/core/src/subgraph/instance_manager.rs b/core/src/subgraph/instance_manager.rs
@@ -964,8 +964,22 @@ where
             host_metrics.clone(),
         )?;
 
-        data_sources.push(data_source);
-        runtime_hosts.push(host);
+        match host {
+            Some(host) => {
+                data_sources.push(data_source);
+                runtime_hosts.push(host);
+            }
+            None => warn!(
+                logger,
+                "no runtime hosted created, there is already a runtime host instantiated for \
+                 this data source";
+                "name" => &data_source.name,
+                "address" => &data_source.source.address
+                    .map(|address| address.to_string())
+                    .unwrap_or("none".to_string()),
+                "abi" => &data_source.source.abi
+            ),
+        }
     }
 
     Ok((data_sources, runtime_hosts))
diff --git a/graph/src/components/subgraph/host.rs b/graph/src/components/subgraph/host.rs
@@ -1,3 +1,4 @@
+use std::cmp::PartialEq;
 use std::fmt;
 use std::sync::Arc;
 
@@ -145,7 +146,7 @@ impl HostMetrics {
 }
 
 pub trait RuntimeHostBuilder: Clone + Send + Sync + 'static {
-    type Host: RuntimeHost;
+    type Host: RuntimeHost + PartialEq;
     type Req: 'static + Send;
 
     /// Build a new runtime host for a subgraph data source.
diff --git a/graph/src/components/subgraph/instance.rs b/graph/src/components/subgraph/instance.rs
@@ -61,5 +61,5 @@ pub trait SubgraphInstance<H: RuntimeHost> {
         data_source: DataSource,
         top_level_templates: Arc<Vec<DataSourceTemplate>>,
         metrics: Arc<HostMetrics>,
-    ) -> Result<Arc<H>, anyhow::Error>;
+    ) -> Result<Option<Arc<H>>, anyhow::Error>;
 }
diff --git a/graph/src/data/subgraph/mod.rs b/graph/src/data/subgraph/mod.rs
@@ -488,7 +488,7 @@ impl From<EthereumContractAbiEntity> for UnresolvedMappingABI {
     }
 }
 
-#[derive(Clone, Debug)]
+#[derive(Clone, Debug, PartialEq)]
 pub struct MappingABI {
     pub name: String,
     pub contract: Contract,
diff --git a/runtime/wasm/src/host.rs b/runtime/wasm/src/host.rs
@@ -1,3 +1,4 @@
+use std::cmp::PartialEq;
 use std::collections::HashMap;
 use std::str::FromStr;
 use std::time::{Duration, Instant};
@@ -719,3 +720,16 @@ impl RuntimeHostTrait for RuntimeHost {
         .await
     }
 }
+
+impl PartialEq for RuntimeHost {
+    fn eq(&self, other: &Self) -> bool {
+        // mapping_request_sender, host_exports and host_metrics are operational structs not needed
+        // to define uniqueness; each runtime host should be for a unique data source.
+        self.data_source_name == other.data_source_name
+            && self.data_source_contract == other.data_source_contract
+            && self.data_source_contract_abi == other.data_source_contract_abi
+            && self.data_source_event_handlers == other.data_source_event_handlers
+            && self.data_source_call_handlers == other.data_source_call_handlers
+            && self.data_source_block_handlers == other.data_source_block_handlers
+    }
+}

Original file line number	Diff line number	Diff line change
`@@ -61,5 +61,5 @@ pub trait SubgraphInstance<H: RuntimeHost> {`
`61`	`61`	`data_source: DataSource,`
`62`	`62`	`top_level_templates: Arc<Vec<DataSourceTemplate>>,`
`63`	`63`	`metrics: Arc<HostMetrics>,`
`64`		`- ) -> Result<Arc<H>, anyhow::Error>;`
	`64`	`+ ) -> Result<Option<Arc<H>>, anyhow::Error>;`
`65`	`65`	`}`
Original file line number	Diff line number	Diff line change
`@@ -488,7 +488,7 @@ impl From<EthereumContractAbiEntity> for UnresolvedMappingABI {`
`488`	`488`	`}`
`489`	`489`	`}`
`490`	`490`
`491`		`-#[derive(Clone, Debug)]`
	`491`	`+#[derive(Clone, Debug, PartialEq)]`
`492`	`492`	`pub struct MappingABI {`
`493`	`493`	`pub name: String,`
`494`	`494`	`pub contract: Contract,`