chain, store: Adapt to different serialization forms for a block

Author: lutter

chain/ethereum/src/chain.rs

@@ -419,6 +419,23 @@ impl Block for BlockFinality {
     }
 
     fn data(&self) -> Result<json::Value, json::Error> {
+        // The serialization here very delicately depends on how the
+        // `ChainStore`'s `blocks` and `ancestor_block` return the data we
+        // store here. This should be fixed in a better way to ensure we
+        // serialize/deserialize appropriately.
+        //
+        // Commit #d62e9846 inadvertently introduced a variation in how
+        // chain stores store ethereum blocks in that they now sometimes
+        // store an `EthereumBlock` that has a `block` field with a
+        // `LightEthereumBlock`, and sometimes they just store the
+        // `LightEthereumBlock` directly. That causes issues because the
+        // code reading from the chain store always expects the JSON data to
+        // have the form of an `EthereumBlock`.
+        //
+        // The serialization here will subtly use different formats because
+        // it serializes objects of different types.
+        //
+        // see also 7736e440-4c6b-11ec-8c4d-b42e99f52061
         match self {
             BlockFinality::Final(block) => json::to_value(block),
             BlockFinality::NonFinal(block) => json::to_value(&block.ethereum_block),

store/postgres/src/chain_store.rs

@@ -486,12 +486,19 @@ mod data {
         ) -> Result<Vec<json::Value>, Error> {
             use diesel::dsl::any;
 
+            // We need to deal with chain stores where some entries have a
+            // toplevel 'block' field and others directly contain what would
+            // be in the 'block' field. Make sure we return the contents of
+            // the 'block' field if it exists, otherwise assume the whole
+            // Json object is what should be in 'block'
+            //
+            // see also 7736e440-4c6b-11ec-8c4d-b42e99f52061
             match self {
                 Storage::Shared => {
                     use public::ethereum_blocks as b;
 
                     b::table
-                        .select(sql::<Jsonb>("data -> 'block'"))
+                        .select(sql::<Jsonb>("coalesce(data -> 'block', data)"))
                         .filter(b::network_name.eq(chain))
                         .filter(b::hash.eq(any(Vec::from_iter(
                             hashes.into_iter().map(|h| format!("{:x}", h)),
@@ -500,7 +507,7 @@ mod data {
                 }
                 Storage::Private(Schema { blocks, .. }) => blocks
                     .table()
-                    .select(sql::<Jsonb>("data -> 'block'"))
+                    .select(sql::<Jsonb>("coalesce(data -> 'block', data)"))
                     .filter(
                         blocks
                             .hash()
@@ -835,6 +842,20 @@ mod data {
                 }
             };
 
+            // We need to deal with chain stores where some entries have a
+            // toplevel 'blocks' field and others directly contain what
+            // would be in the 'blocks' field. Make sure the value we return
+            // has a 'block' entry
+            //
+            // see also 7736e440-4c6b-11ec-8c4d-b42e99f52061
+            let data = {
+                use graph::prelude::serde_json::json;
+
+                data.map(|data| match data.get("block") {
+                    Some(_) => data,
+                    None => json!({ "block": data, "transaction_receipts": [] }),
+                })
+            };
             Ok(data)
         }