import 14.2.4 nautilus point release

[ceph.git] / ceph / src / rocksdb / db / read_callback.h

diff --git a/ceph/src/rocksdb/db/read_callback.h b/ceph/src/rocksdb/db/read_callback.h
index 440f7848ddcdaa72fdd254e277ce83462364e1a9..52573be19d0904e973ffed1ed67ca996cec81aec 100644 (file)
--- a/ceph/src/rocksdb/db/read_callback.h
+++ b/ceph/src/rocksdb/db/read_callback.h
@@ -11,20 +11,45 @@ namespace rocksdb {
 
 class ReadCallback {
  public:
+  ReadCallback(SequenceNumber last_visible_seq)
+      : max_visible_seq_(last_visible_seq) {}
+  ReadCallback(SequenceNumber last_visible_seq, SequenceNumber min_uncommitted)
+      : max_visible_seq_(last_visible_seq), min_uncommitted_(min_uncommitted) {}
+
   virtual ~ReadCallback() {}
 
   // Will be called to see if the seq number visible; if not it moves on to
   // the next seq number.
-  virtual bool IsVisible(SequenceNumber seq) = 0;
-
-  // This is called to determine the maximum visible sequence number for the
-  // current transaction for read-your-own-write semantics. This is so that
-  // for write unprepared, we will not skip keys that are written by the
-  // current transaction with the seek to snapshot optimization.
-  //
-  // For other uses, this returns zero, meaning that the current snapshot
-  // sequence number is the maximum visible sequence number.
-  inline virtual SequenceNumber MaxUnpreparedSequenceNumber() { return 0; };
+  virtual bool IsVisibleFullCheck(SequenceNumber seq) = 0;
+
+  inline bool IsVisible(SequenceNumber seq) {
+    assert(min_uncommitted_ > 0);
+    assert(min_uncommitted_ >= kMinUnCommittedSeq);
+    if (seq < min_uncommitted_) {  // handles seq == 0 as well
+      assert(seq <= max_visible_seq_);
+      return true;
+    } else if (max_visible_seq_ < seq) {
+      assert(seq != 0);
+      return false;
+    } else {
+      assert(seq != 0);  // already handled in the first if-then clause
+      return IsVisibleFullCheck(seq);
+    }
+  }
+
+  inline SequenceNumber max_visible_seq() { return max_visible_seq_; }
+
+  virtual void Refresh(SequenceNumber seq) { max_visible_seq_ = seq; }
+
+  // Refer to DBIter::CanReseekToSkip
+  virtual bool CanReseekToSkip() { return true; }
+
+ protected:
+  // The max visible seq, it is usually the snapshot but could be larger if
+  // transaction has its own writes written to db.
+  SequenceNumber max_visible_seq_ = kMaxSequenceNumber;
+  // Any seq less than min_uncommitted_ is committed.
+  const SequenceNumber min_uncommitted_ = kMinUnCommittedSeq;
 };
 
 }  //  namespace rocksdb