Truncate logs immediately upon collection. Also reduce limit from 100k to 10k (#13774)

(cherry picked from commit 60ce6f1a9b)

Co-authored-by: Michael Vines <mvines@gmail.com>

runtime/src/bank.rs

@@ -114,8 +114,6 @@ pub const SECONDS_PER_YEAR: f64 = 365.25 * 24.0 * 60.0 * 60.0;
 
 pub const MAX_LEADER_SCHEDULE_STAKES: Epoch = 5;
 
-pub const TRANSACTION_LOG_MESSAGES_BYTES_LIMIT: usize = 100 * 1000;
-
 type BankStatusCache = StatusCache<Result<()>>;
 #[frozen_abi(digest = "4nZ6EdivqQPcnrnXisbjuTjpcUBoHLDEQWvbZQDCoQQR")]
 pub type BankSlotDelta = SlotDelta<Result<()>>;
@@ -2531,22 +2529,6 @@ impl Bank {
         cache.remove(pubkey);
     }
 
-    pub fn truncate_log_messages(
-        log_messages: &mut TransactionLogMessages,
-        max_bytes: usize,
-        truncate_message: String,
-    ) {
-        let mut size = 0;
-        for (i, line) in log_messages.iter().enumerate() {
-            size += line.len();
-            if size > max_bytes {
-                log_messages.truncate(i);
-                log_messages.push(truncate_message);
-                return;
-            }
-        }
-    }
-
     #[allow(clippy::type_complexity)]
     pub fn load_and_execute_transactions(
         &self,
@@ -2647,17 +2629,11 @@ impl Bank {
                     );
 
                     if enable_log_recording {
-                        let mut log_messages: TransactionLogMessages =
+                        let log_messages: TransactionLogMessages =
                             Rc::try_unwrap(log_collector.unwrap_or_default())
                                 .unwrap_or_default()
                                 .into();
 
-                        Self::truncate_log_messages(
-                            &mut log_messages,
-                            TRANSACTION_LOG_MESSAGES_BYTES_LIMIT,
-                            String::from("<< Transaction log truncated to 100KB >>\n"),
-                        );
-
                         transaction_logs.push(log_messages);
                     }
 
@@ -10432,55 +10408,6 @@ pub(crate) mod tests {
         assert_eq!(old_hash, new_bank1_hash);
     }
 
-    #[test]
-    fn test_truncate_log_messages() {
-        let mut messages = vec![
-            String::from("This is line one\n"),
-            String::from("This is line two\n"),
-            String::from("This is line three\n"),
-        ];
-
-        // messages under limit
-        Bank::truncate_log_messages(
-            &mut messages,
-            10000,
-            String::from("<< Transaction log truncated to 10,000 bytes >>\n"),
-        );
-        assert_eq!(messages.len(), 3);
-
-        // messages truncated to two lines
-        let maxsize = messages.get(0).unwrap().len() + messages.get(1).unwrap().len();
-        Bank::truncate_log_messages(
-            &mut messages,
-            maxsize,
-            String::from("<< Transaction log truncated >>\n"),
-        );
-        assert_eq!(messages.len(), 3);
-        assert_eq!(
-            messages.get(2).unwrap(),
-            "<< Transaction log truncated >>\n"
-        );
-
-        // messages truncated to one line
-        let mut messages = vec![
-            String::from("Line 1\n"),
-            String::from("Line 2\n"),
-            String::from("Line 3\n"),
-        ];
-
-        let maxsize = messages.get(0).unwrap().len() + 4;
-        Bank::truncate_log_messages(
-            &mut messages,
-            maxsize,
-            String::from("<< Transaction log truncated >>\n"),
-        );
-        assert_eq!(messages.len(), 2);
-        assert_eq!(
-            messages.get(1).unwrap(),
-            "<< Transaction log truncated >>\n"
-        );
-    }
-
     #[test]
     fn test_program_is_native_loader() {
         let (genesis_config, mint_keypair) = create_genesis_config(50000);

runtime/src/log_collector.rs

@@ -1,18 +1,58 @@
 use std::cell::RefCell;
 
+const LOG_MESSAGES_BYTES_LIMIT: usize = 10 * 1000;
+
+#[derive(Default)]
+struct LogCollectorInner {
+    messages: Vec<String>,
+    bytes_written: usize,
+    limit_warning: bool,
+}
+
 #[derive(Default)]
 pub struct LogCollector {
-    messages: RefCell<Vec<String>>,
+    inner: RefCell<LogCollectorInner>,
 }
 
 impl LogCollector {
     pub fn log(&self, message: &str) {
-        self.messages.borrow_mut().push(message.to_string())
+        let mut inner = self.inner.borrow_mut();
+
+        if inner.bytes_written + message.len() >= LOG_MESSAGES_BYTES_LIMIT {
+            if !inner.limit_warning {
+                inner.limit_warning = true;
+                inner.messages.push(String::from("Log truncated"));
+            }
+        } else {
+            inner.bytes_written += message.len();
+            inner.messages.push(message.to_string());
+        }
     }
 }
 
 impl Into<Vec<String>> for LogCollector {
     fn into(self) -> Vec<String> {
-        self.messages.into_inner()
+        self.inner.into_inner().messages
+    }
+}
+
+#[cfg(test)]
+pub(crate) mod tests {
+    use super::*;
+
+    #[test]
+    fn test_log_messages_bytes_limit() {
+        let lc = LogCollector::default();
+
+        for _i in 0..LOG_MESSAGES_BYTES_LIMIT * 2 {
+            lc.log("x");
+        }
+
+        let logs: Vec<_> = lc.into();
+        assert_eq!(logs.len(), LOG_MESSAGES_BYTES_LIMIT);
+        for log in logs.iter().take(LOG_MESSAGES_BYTES_LIMIT - 1) {
+            assert_eq!(*log, "x".to_string());
+        }
+        assert_eq!(logs.last(), Some(&"Log truncated".to_string()));
     }
 }