Bugfix/515

src/dbzero/core/storage/BDevStorage.cpp

@@ -332,11 +332,14 @@ namespace db0
         m_sparse_pair.extractChangeLog(m_dp_changelog_io);
         m_dram_io.flushUpdates(state_num, m_dram_changelog_io);
         m_dp_changelog_io.flush();
-        // flush changelog AFTER all updates from dram_io have been flushed
-        m_dram_changelog_io.flush();
         m_page_io.flush();
         // NOTE: fsync has stronger guarantees than flush in a multi-process environments
         m_file.fsync();
+        // flush changelog AFTER all updates from all other streams have been flushed
+        m_dram_changelog_io.flush();
+        // the last fsync finalizes the commit
+        m_file.fsync();
+
         // commit to collect future updates correctly
         m_sparse_pair.commit();
         return true;
@@ -458,7 +461,7 @@ namespace db0
     {
         assert(m_access_type == AccessType::READ_ONLY);
         std::uint64_t result = 0;
-        // continue refreshing until all updates retrieved to guarantee a consistent state
+        // continue refreshing until all updates are retrieved to guarantee a consistent state
         do {
             // safe stream positions for rollback on file read failure
             auto dram_changelog_io_pos = m_dram_changelog_io.getStreamPos();

src/dbzero/core/storage/BlockIOStream.cpp

@@ -457,7 +457,7 @@ namespace db0
     bool BlockIOStream::eos() const {
         return m_eos;
     }
-
+    
     bool BlockIOStream::readBlock(std::uint64_t address, void *buffer)
     {        
         if (m_checksums_enabled) {

src/dbzero/core/storage/BlockIOStream.hpp

@@ -13,14 +13,14 @@
 namespace db0
 
 {
-DB0_PACKED_BEGIN
 
     /**
      * Calculate a buffer's checksum (must be aligned to 8 bytes)
     */
     std::uint64_t checksum(const void *begin, const void *end);
 
     // block level header
+DB0_PACKED_BEGIN
     struct DB0_PACKED_ATTR o_block_io_block_header: public o_fixed<o_block_io_block_header>
     {
         std::uint64_t m_next_block_address = 0;
@@ -34,8 +34,10 @@ DB0_PACKED_BEGIN
             m_next_block_address = address;
         }
     };
-
+DB0_PACKED_END
+
     // block level header with a checksum
+DB0_PACKED_BEGIN
     struct DB0_PACKED_ATTR o_block_io_cs_block_header:
     public o_fixed_ext<o_block_io_cs_block_header, o_block_io_block_header>
     {        
@@ -47,9 +49,11 @@ DB0_PACKED_BEGIN
             // calculate checksum of this object excluding the checksum field
             return checksum((const char*)this, (const char*)this + sizeOf() - sizeof(m_block_checksum));
         }
-    };
-
+    };    
+DB0_PACKED_END
+
     // chunk level header
+DB0_PACKED_BEGIN
     struct DB0_PACKED_ATTR o_block_io_chunk_header: public o_fixed<o_block_io_chunk_header>
     {
         std::uint32_t m_chunk_size = 0;
@@ -64,6 +68,7 @@ DB0_PACKED_BEGIN
             return m_chunk_size != 0;
         }
     };
+DB0_PACKED_END
 
     /**
      * Stream of blocks embeddable into the .db0 file        
@@ -282,5 +287,4 @@ DB0_PACKED_BEGIN
         std::uint64_t nextAddress() const;
     };
 
-DB0_PACKED_END
 }

src/dbzero/core/storage/ChangeLogIOStream.cpp

@@ -7,11 +7,11 @@ namespace db0
 
     ChangeLogIOStream::ChangeLogIOStream(CFile &m_file, std::uint64_t begin, std::uint32_t block_size,
         std::function<std::uint64_t()> tail_function, AccessType access_type)
-        // enable checksums
+        // enable checksums by default
         : BlockIOStream(m_file, begin, block_size, tail_function, access_type, true)
     {
     }
-
+    
     ChangeLogIOStream::ChangeLogIOStream(BlockIOStream &&io_stream)
         : BlockIOStream(std::move(io_stream))
     {

src/dbzero/workspace/Fixture.cpp

@@ -181,7 +181,7 @@ namespace db0
         if (timer_ptr) {
             timer = std::make_unique<ProcessTimer>("Fixture::close", timer_ptr);
         }
-
+                        
         // clear cache to destroy object instances supported by the cache
         // this has to be done before commit (to not commit unrefereced objects)
         m_lang_cache.clear(true, as_defunct);