pegasus: remove single cf assert & ignore 0 value decree update (#28)

db/db_filesnapshot.cc

@@ -159,9 +159,6 @@ Status DBImpl::GetLiveFilesQuick(std::vector<std::string>& ret,
 
   mutex_.Lock();
 
-  // ATTENTION(qinzuoyan): only use default column family.
-  assert(versions_->GetColumnFamilySet()->NumberOfColumnFamilies() == 1u);
-
   // Make a set of all of the live *.sst files
   std::vector<FileDescriptor> live;
   for (auto cfd : *versions_->GetColumnFamilySet()) {
@@ -174,9 +171,12 @@ Status DBImpl::GetLiveFilesQuick(std::vector<std::string>& ret,
     uint64_t d;
     cfd->current()->GetLastFlushSeqDecree(&seq, &d);
     if (seq > *last_sequence) {
-      assert(d >= *last_decree);
       *last_sequence = seq;
-      *last_decree = d;
+      // Pegasus decree is only written on default column family consistently.
+      if (cfd->GetID() == 0) {
+        assert(d >= *last_decree);
+        *last_decree = d;
+      }
     }
   }
 

db/db_impl/db_impl.cc

@@ -1275,8 +1275,6 @@ uint64_t DBImpl::GetLastFlushedDecree() const {
   uint64_t d;
 
   mutex_.Lock();
-  // ATTENTION(qinzuoyan): only use default column family.
-  assert(!pegasus_data_ || versions_->GetColumnFamilySet()->NumberOfColumnFamilies() == 1u);
   versions_->GetColumnFamilySet()->GetDefault()->current()->GetLastFlushSeqDecree(&seq, &d);
   mutex_.Unlock();
 

db/db_impl/db_impl_write.cc

@@ -100,10 +100,6 @@ Status DBImpl::WriteImpl(const WriteOptions& write_options,
   assert(!WriteBatchInternal::IsLatestPersistentState(my_batch) ||
          disable_memtable);
 
-  // ATTENTION(qinzuoyan): always only use default column family under
-  // replication framework.
-  assert(!pegasus_data_ || single_column_family_mode_);
-
   Status status;
   if (write_options.low_pri) {
     status = ThrottleLowPriWritesIfNeeded(write_options, my_batch);

db/memtable.h

@@ -441,9 +441,12 @@ class MemTable {
 
   void UpdateLastSeqDecree(SequenceNumber sequence, uint64_t decree) {
     assert(sequence > last_sequence_); // sequence should not be shared
-    assert(decree >= last_decree_); // decree may be shared
     last_sequence_ = sequence;
-    last_decree_ = decree;
+    // decree of non-default column family would be 0, don't record it
+    if (decree != 0) {
+      assert(decree >= last_decree_); // decree may be shared
+      last_decree_ = decree;
+    }
   }
 
  private:

db/version_edit.h

@@ -311,9 +311,12 @@ class VersionEdit {
 
   void UpdateLastFlushSeqDecree(SequenceNumber sequence, uint64_t decree) {
     if (sequence > last_flush_sequence_) {
-      assert(decree >= last_flush_decree_);
       last_flush_sequence_ = sequence;
-      last_flush_decree_ = decree;
+      // decree of non-default column family would be 0, don't record it
+      if (decree != 0) {
+        assert(decree >= last_flush_decree_);
+        last_flush_decree_ = decree;
+      }
       has_last_flush_seq_decree_ = true;
     }
   }

db/version_set.h

@@ -689,9 +689,12 @@ class Version {
 
   void UpdateLastFlushSeqDecreeIfNeeded(SequenceNumber sequence, uint64_t decree) {
     if (sequence > last_flush_sequence_) {
-      assert(decree >= last_flush_decree_);
       last_flush_sequence_ = sequence;
-      last_flush_decree_ = decree;
+      // decree of non-default column family would be 0, don't record it
+      if (decree != 0) {
+        assert(decree >= last_flush_decree_);
+        last_flush_decree_ = decree;
+      }
     }
   }
 
@@ -964,7 +967,6 @@ class VersionSet {
   // Return the last flush sequence number of default column family.
   uint64_t LastFlushSequence() const {
     assert(db_options_->pegasus_data);
-    assert(column_family_set_->NumberOfColumnFamilies() == 1u);
     SequenceNumber seq;
     uint64_t d;
     column_family_set_->GetDefault()->current()->GetLastFlushSeqDecree(&seq, &d);