From 51fd017c5b42b1fc5cfe0edeb0a6b0fc05e3daee Mon Sep 17 00:00:00 2001
From: "hinto.janai" <hinto.janai@protonmail.com>
Date: Fri, 6 Sep 2024 17:16:13 -0400
Subject: [PATCH] blockchain: add
 `BlockchainReadRequest::BlockExtendedHeaderByHash`

---
 storage/blockchain/src/service/read.rs | 17 ++++++++++++++++-
 types/src/blockchain.rs                | 10 ++++++++++
 2 files changed, 26 insertions(+), 1 deletion(-)

diff --git a/storage/blockchain/src/service/read.rs b/storage/blockchain/src/service/read.rs
index 207da416..2114280b 100644
--- a/storage/blockchain/src/service/read.rs
+++ b/storage/blockchain/src/service/read.rs
@@ -23,7 +23,8 @@ use cuprate_types::{
 use crate::{
     ops::{
         block::{
-            block_exists, get_block_extended_header_from_height, get_block_height, get_block_info,
+            block_exists, get_block_extended_header, get_block_extended_header_from_height,
+            get_block_height, get_block_info,
         },
         blockchain::{cumulative_generated_coins, top_block_height},
         key_image::key_image_exists,
@@ -86,6 +87,7 @@ fn map_request(
 
     match request {
         R::BlockExtendedHeader(block) => block_extended_header(env, block),
+        R::BlockExtendedHeaderByHash(block) => block_extended_header_by_hash(env, block),
         R::BlockHash(block, chain) => block_hash(env, block, chain),
         R::FindBlock(_) => todo!("Add alt blocks to DB"),
         R::FilterUnknownHashes(hashes) => filter_unknown_hashes(env, hashes),
@@ -188,6 +190,19 @@ fn block_extended_header(env: &ConcreteEnv, block_height: BlockHeight) -> Respon
     ))
 }
 
+/// [`BlockchainReadRequest::BlockExtendedHeaderByHash`].
+#[inline]
+fn block_extended_header_by_hash(env: &ConcreteEnv, block_hash: BlockHash) -> ResponseResult {
+    // Single-threaded, no `ThreadLocal` required.
+    let env_inner = env.env_inner();
+    let tx_ro = env_inner.tx_ro()?;
+    let tables = env_inner.open_tables(&tx_ro)?;
+
+    Ok(BlockchainResponse::BlockExtendedHeaderByHash(
+        get_block_extended_header(&block_hash, &tables)?,
+    ))
+}
+
 /// [`BlockchainReadRequest::BlockHash`].
 #[inline]
 fn block_hash(env: &ConcreteEnv, block_height: BlockHeight, chain: Chain) -> ResponseResult {
diff --git a/types/src/blockchain.rs b/types/src/blockchain.rs
index b502c3fa..dcf472e3 100644
--- a/types/src/blockchain.rs
+++ b/types/src/blockchain.rs
@@ -27,6 +27,11 @@ pub enum BlockchainReadRequest {
     /// The input is the block's height.
     BlockExtendedHeader(usize),
 
+    /// Request a block's extended header.
+    ///
+    /// The input is the block's hash.
+    BlockExtendedHeaderByHash([u8; 32]),
+
     /// Request a block's hash.
     ///
     /// The input is the block's height and the chain it is on.
@@ -129,6 +134,11 @@ pub enum BlockchainResponse {
     /// Inner value is the extended headed of the requested block.
     BlockExtendedHeader(ExtendedBlockHeader),
 
+    /// Response to [`BlockchainReadRequest::BlockExtendedHeaderByHash`].
+    ///
+    /// Inner value is the extended headed of the requested block.
+    BlockExtendedHeaderByHash(ExtendedBlockHeader),
+
     /// Response to [`BlockchainReadRequest::BlockHash`].
     ///
     /// Inner value is the hash of the requested block.