expose seqno from compaction filter and iterator

db/compact_files_test.cc

@@ -141,7 +141,6 @@ TEST_F(CompactFilesTest, FilterContext) {
   db->CompactRange(CompactRangeOptions(), nullptr, nullptr);
   usleep(10000); // Wait for compaction start.
   ASSERT_EQ(expected_context->start_key, Slice("1"));
-  ASSERT_EQ(expected_context->end_key, Slice("99"));
   ASSERT_EQ(expected_context->is_end_key_inclusive, 1);
   ASSERT_EQ(expected_context->file_numbers[0], 11);
   ASSERT_EQ(*compaction_count.get(), 2);

db/compaction/compaction_iterator.cc

@@ -172,10 +172,11 @@ void CompactionIterator::InvokeFilterIfNeeded(bool* need_skip,
     // Hack: pass internal key to BlobIndexCompactionFilter since it needs
     // to get sequence number.
     Slice& filter_key = ikey_.type == kTypeValue ? ikey_.user_key : key_;
+    SequenceNumber seqno = ikey_.sequence;
     {
       StopWatchNano timer(env_, report_detailed_time_);
-      filter = compaction_filter_->FilterV2(
-          compaction_->level(), filter_key, value_type, value_,
+      filter = compaction_filter_->FilterV3(
+          compaction_->level(), filter_key, seqno, value_type, value_,
           &compaction_filter_value_, compaction_filter_skip_until_.rep());
       iter_stats_.total_filter_time +=
           env_ != nullptr && report_detailed_time_ ? timer.ElapsedNanos() : 0;
@@ -185,7 +186,7 @@ void CompactionIterator::InvokeFilterIfNeeded(bool* need_skip,
         cmp_->Compare(*compaction_filter_skip_until_.rep(), ikey_.user_key) <=
             0) {
       // Can't skip to a key smaller than the current one.
-      // Keep the key as per FilterV2 documentation.
+      // Keep the key as per FilterV3 documentation.
       filter = CompactionFilter::Decision::kKeep;
     }
 

db/db_iter.cc

@@ -195,6 +195,11 @@ class DBIter final: public Iterator {
       return iter_.value();
     }
   }
+  bool seqno(SequenceNumber* no) const override {
+    assert(valid_);
+    *no = ikey_.sequence;
+    return true;
+  }
   Status status() const override {
     if (status_.ok()) {
       return iter_.status();
@@ -1602,6 +1607,9 @@ inline void ArenaWrappedDBIter::Next() { db_iter_->Next(); }
 inline void ArenaWrappedDBIter::Prev() { db_iter_->Prev(); }
 inline Slice ArenaWrappedDBIter::key() const { return db_iter_->key(); }
 inline Slice ArenaWrappedDBIter::value() const { return db_iter_->value(); }
+inline bool ArenaWrappedDBIter::seqno(SequenceNumber* no) const {
+  return db_iter_->seqno(no);
+}
 inline Status ArenaWrappedDBIter::status() const { return db_iter_->status(); }
 bool ArenaWrappedDBIter::IsBlob() const { return db_iter_->IsBlob(); }
 inline Status ArenaWrappedDBIter::GetProperty(std::string prop_name,

db/db_iter.h

@@ -89,6 +89,7 @@ class ArenaWrappedDBIter : public Iterator {
   virtual void Prev() override;
   virtual Slice key() const override;
   virtual Slice value() const override;
+  virtual bool seqno(SequenceNumber* no) const override;
   virtual Status status() const override;
   virtual Status Refresh() override;
   bool IsBlob() const;

include/rocksdb/compaction_filter.h

@@ -130,6 +130,30 @@ class CompactionFilter {
     return false;
   }
 
+  // Almost same as FilterV3, except won't pass out sequence numbers.
+  virtual Decision FilterV2(int level, const Slice& key, ValueType value_type,
+                            const Slice& existing_value, std::string* new_value,
+                            std::string* /*skip_until*/) const {
+    switch (value_type) {
+      case ValueType::kValue: {
+        bool value_changed = false;
+        bool rv = Filter(level, key, existing_value, new_value, &value_changed);
+        if (rv) {
+          return Decision::kRemove;
+        }
+        return value_changed ? Decision::kChangeValue : Decision::kKeep;
+      }
+      case ValueType::kMergeOperand: {
+        bool rv = FilterMergeOperand(level, key, existing_value);
+        return rv ? Decision::kRemove : Decision::kKeep;
+      }
+      case ValueType::kBlobIndex:
+        return Decision::kKeep;
+    }
+    assert(false);
+    return Decision::kKeep;
+  }
+
   // An extended API. Called for both values and merge operands.
   // Allows changing value and skipping ranges of keys.
   // The default implementation uses Filter() and FilterMergeOperand().
@@ -169,27 +193,14 @@ class CompactionFilter {
   // is a write conflict and may allow a Transaction to Commit that should have
   // failed. Instead, it is better to implement any Merge filtering inside the
   // MergeOperator.
-  virtual Decision FilterV2(int level, const Slice& key, ValueType value_type,
+  //
+  // Note: for kTypeBlobIndex, `key` is internal key instead of user key.
+  virtual Decision FilterV3(int level, const Slice& key,
+                            SequenceNumber /*seqno*/, ValueType value_type,
                             const Slice& existing_value, std::string* new_value,
-                            std::string* /*skip_until*/) const {
-    switch (value_type) {
-      case ValueType::kValue: {
-        bool value_changed = false;
-        bool rv = Filter(level, key, existing_value, new_value, &value_changed);
-        if (rv) {
-          return Decision::kRemove;
-        }
-        return value_changed ? Decision::kChangeValue : Decision::kKeep;
-      }
-      case ValueType::kMergeOperand: {
-        bool rv = FilterMergeOperand(level, key, existing_value);
-        return rv ? Decision::kRemove : Decision::kKeep;
-      }
-      case ValueType::kBlobIndex:
-        return Decision::kKeep;
-    }
-    assert(false);
-    return Decision::kKeep;
+                            std::string* skip_until) const {
+    return FilterV2(level, key, value_type, existing_value, new_value,
+                    skip_until);
   }
 
   // This function is deprecated. Snapshots will always be ignored for

include/rocksdb/iterator.h

@@ -22,6 +22,7 @@
 #include "rocksdb/cleanable.h"
 #include "rocksdb/slice.h"
 #include "rocksdb/status.h"
+#include "rocksdb/types.h"
 
 namespace rocksdb {
 
@@ -78,6 +79,11 @@ class Iterator : public Cleanable {
   // REQUIRES: Valid()
   virtual Slice value() const = 0;
 
+  // Return the sequence number for the current entry if it's available.
+  // Return false if it's not available.
+  // REQUIRES: Valid()
+  virtual bool seqno(SequenceNumber* /*seqno*/) const { return false; }
+
   // If an error has occurred, return it.  Else return an ok status.
   // If non-blocking IO is requested and this operation cannot be
   // satisfied without doing some IO, then this returns Status::Incomplete().

utilities/blob_db/blob_db_iterator.h

@@ -111,6 +111,8 @@ class BlobDBIterator : public Iterator {
     return value_;
   }
 
+  bool seqno(SequenceNumber* no) const override { return iter_->seqno(no); }
+
   // Iterator::Refresh() not supported.
 
  private:

utilities/ttl/db_ttl_impl.h

@@ -143,6 +143,8 @@ class TtlIterator : public Iterator {
     return trimmed_value;
   }
 
+  bool seqno(SequenceNumber* no) const override { return iter_->seqno(no); }
+
   Status status() const override { return iter_->status(); }
 
  private: