Add block height to ConfirmedBlock structs (#17523)

* Add BlockHeight CF to blockstore

* Rename CacheBlockTimeService to be more general

* Cache block-height using service

* Fixup previous proto mishandling

* Add block_height to block structs

* Add block-height to solana block

* Fallback to BankForks if block time or block height are not yet written to Blockstore

* Add docs

* Review comments

core/src/cache_block_meta_service.rs

@@ -0,0 +1,74 @@
+pub use solana_ledger::blockstore_processor::CacheBlockMetaSender;
+use {
+    crossbeam_channel::{Receiver, RecvTimeoutError},
+    solana_ledger::blockstore::Blockstore,
+    solana_measure::measure::Measure,
+    solana_runtime::bank::Bank,
+    std::{
+        sync::{
+            atomic::{AtomicBool, Ordering},
+            Arc,
+        },
+        thread::{self, Builder, JoinHandle},
+        time::Duration,
+    },
+};
+
+pub type CacheBlockMetaReceiver = Receiver<Arc<Bank>>;
+
+pub struct CacheBlockMetaService {
+    thread_hdl: JoinHandle<()>,
+}
+
+const CACHE_BLOCK_TIME_WARNING_MS: u64 = 150;
+
+impl CacheBlockMetaService {
+    #[allow(clippy::new_ret_no_self)]
+    pub fn new(
+        cache_block_meta_receiver: CacheBlockMetaReceiver,
+        blockstore: Arc<Blockstore>,
+        exit: &Arc<AtomicBool>,
+    ) -> Self {
+        let exit = exit.clone();
+        let thread_hdl = Builder::new()
+            .name("solana-cache-block-time".to_string())
+            .spawn(move || loop {
+                if exit.load(Ordering::Relaxed) {
+                    break;
+                }
+                let recv_result = cache_block_meta_receiver.recv_timeout(Duration::from_secs(1));
+                match recv_result {
+                    Err(RecvTimeoutError::Disconnected) => {
+                        break;
+                    }
+                    Ok(bank) => {
+                        let mut cache_block_meta_timer = Measure::start("cache_block_meta_timer");
+                        Self::cache_block_meta(bank, &blockstore);
+                        cache_block_meta_timer.stop();
+                        if cache_block_meta_timer.as_ms() > CACHE_BLOCK_TIME_WARNING_MS {
+                            warn!(
+                                "cache_block_meta operation took: {}ms",
+                                cache_block_meta_timer.as_ms()
+                            );
+                        }
+                    }
+                    _ => {}
+                }
+            })
+            .unwrap();
+        Self { thread_hdl }
+    }
+
+    fn cache_block_meta(bank: Arc<Bank>, blockstore: &Arc<Blockstore>) {
+        if let Err(e) = blockstore.cache_block_time(bank.slot(), bank.clock().unix_timestamp) {
+            error!("cache_block_time failed: slot {:?} {:?}", bank.slot(), e);
+        }
+        if let Err(e) = blockstore.cache_block_height(bank.slot(), bank.block_height()) {
+            error!("cache_block_height failed: slot {:?} {:?}", bank.slot(), e);
+        }
+    }
+
+    pub fn join(self) -> thread::Result<()> {
+        self.thread_hdl.join()
+    }
+}