Implement get validator block endpoint for EIP-4844

beacon_node/http_api/src/build_block_contents.rs

@@ -0,0 +1,34 @@
+use beacon_chain::{BeaconChain, BeaconChainTypes, BlockProductionError};
+use std::sync::Arc;
+use types::{
+    AbstractExecPayload, BeaconBlock, BeaconBlockAndBlobSidecars, BlockContents, ForkName,
+};
+
+type Error = warp::reject::Rejection;
+
+pub fn build_block_contents<T: BeaconChainTypes, Payload: AbstractExecPayload<T::EthSpec>>(
+    fork_name: ForkName,
+    chain: Arc<BeaconChain<T>>,
+    block: BeaconBlock<T::EthSpec, Payload>,
+) -> Result<BlockContents<T::EthSpec, Payload>, Error> {
+    match fork_name {
+        ForkName::Base | ForkName::Altair | ForkName::Merge | ForkName::Capella => {
+            Ok(BlockContents::Block(block))
+        }
+        ForkName::Eip4844 => {
+            let block_root = &block.canonical_root();
+            if let Some(blob_sidecars) = chain.blob_cache.pop(block_root) {
+                let block_and_blobs = BeaconBlockAndBlobSidecars {
+                    block,
+                    blob_sidecars,
+                };
+
+                Ok(BlockContents::BlockAndBlobSidecars(block_and_blobs))
+            } else {
+                return Err(warp_utils::reject::block_production_error(
+                    BlockProductionError::NoBlobsCached,
+                ));
+            }
+        }
+    }
+}