add a test

Signed-off-by: tabokie <xy.tao@outlook.com>

src/log_batch.rs

@@ -27,8 +27,8 @@ const CMD_COMPACT: u8 = 0x02;
 
 const DEFAULT_LOG_ITEM_BATCH_CAP: usize = 64;
 const MAX_LOG_BATCH_BUFFER_CAP: usize = 8 * 1024 * 1024;
-// 2GiB, The maximum content length accepted by lz4 compression.
-const MAX_LOG_ENTRIES_SIZE_PER_BATCH: usize = i32::MAX as usize;
+// LZ4_MAX_INPUT_SIZE = 0x7E000000
+const MAX_LOG_ENTRIES_SIZE_PER_BATCH: usize = 0x7E000000;
 
 /// `MessageExt` trait allows for probing log index from a specific type of
 /// protobuf messages.
@@ -421,15 +421,15 @@ impl LogItemBatch {
 
     #[inline]
     pub fn pop_save_point(&mut self) {
-        self.save_points.pop();
+        self.save_points.pop().unwrap();
     }
 
     #[inline]
-    pub fn rollback(&mut self) {
-        let (a, b, c) = self.save_points.last().unwrap();
-        self.items.truncate(*a);
-        self.item_size = *b;
-        self.entries_size = *c;
+    pub fn rollback_to_save_point(&mut self) {
+        let (a, b, c) = self.save_points.pop().unwrap();
+        self.items.truncate(a);
+        self.item_size = b;
+        self.entries_size = c;
     }
 
     pub(crate) fn finish_populate(&mut self, compression_type: CompressionType) {
@@ -675,15 +675,16 @@ impl LogBatch {
     #[inline]
     pub fn pop_save_point(&mut self) {
         assert!(self.buf_state == BufState::Open);
+        self.item_batch.pop_save_point();
         self.save_points.pop();
     }
 
     /// No-op if there's no save point to rollback to.
     #[inline]
-    pub fn rollback(&mut self) {
+    pub fn rollback_to_save_point(&mut self) {
         assert!(self.buf_state == BufState::Open);
-        self.item_batch.rollback();
-        self.buf.truncate(*self.save_points.last().unwrap());
+        self.item_batch.rollback_to_save_point();
+        self.buf.truncate(self.save_points.pop().unwrap());
     }
 
     /// Adds some protobuf log entries into the log batch.
@@ -1001,7 +1002,9 @@ fn verify_checksum_with_signature(buf: &[u8], signature: Option<u32>) -> Result<
 mod tests {
     use super::*;
     use crate::pipe_log::{LogQueue, Version};
-    use crate::test_util::{catch_unwind_silent, generate_entries, generate_entry_indexes_opt};
+    use crate::test_util::{
+        catch_unwind_silent, generate_entries, generate_entry_indexes_opt, PanicGuard,
+    };
     use protobuf::parse_from_bytes;
     use raft::eraftpb::Entry;
     use strum::IntoEnumIterator;
@@ -1438,6 +1441,57 @@ mod tests {
 
     #[test]
     fn test_save_point() {
+        let ops = [
+            |b: &mut LogBatch| {
+                b.add_entries::<Entry>(1, &generate_entries(1, 11, None))
+                    .unwrap()
+            },
+            |b: &mut LogBatch| {
+                b.add_entries::<Entry>(7, &generate_entries(1, 11, Some(&vec![b'x'; 1024])))
+                    .unwrap()
+            },
+            |b: &mut LogBatch| b.add_command(17, Command::Clean),
+            |b: &mut LogBatch| b.put(27, b"key27".to_vec(), b"value27".to_vec()),
+            |b: &mut LogBatch| b.delete(37, b"key37".to_vec()),
+            |b: &mut LogBatch| b.add_command(47, Command::Compact { index: 777 }),
+            |b: &mut LogBatch| {
+                b.add_entries::<Entry>(57, &generate_entries(1, 51, None))
+                    .unwrap()
+            },
+        ];
+        for start in 0..ops.len() {
+            for stripe in 1..=5 {
+                for num in ops.len()..ops.len() * 5 {
+                    for repeat in 1..=5 {
+                        let _guard = PanicGuard::with_prompt(format!(
+                            "case: [{}, {}, {}, {}]",
+                            start, stripe, num, repeat
+                        ));
+                        let mut to_verify = Vec::new();
+                        let mut batch = LogBatch::default();
+                        let mut op_idx = start;
+                        let mut total_op = 0;
+                        for _ in 0..num {
+                            for _ in 0..repeat {
+                                ops[op_idx % ops.len()](&mut batch);
+                                to_verify.push(batch.clone());
+                                batch.set_save_point();
+                                total_op += 1;
+                                if total_op % 5 == 0 {
+                                    to_verify.pop().unwrap();
+                                    batch.pop_save_point();
+                                }
+                            }
+                            op_idx += stripe;
+                        }
+                        while let Some(b) = to_verify.pop() {
+                            batch.rollback_to_save_point();
+                            assert_eq!(batch, b);
+                        }
+                    }
+                }
+            }
+        }
     }
 
     #[cfg(feature = "nightly")]