Address review: static lambda, remove tz member, remove redundant override

- Make viewToString lambda static in createColumnDispatcher
- Remove m_defaultTimezone member, validate tz inline and discard
- Remove redundant doReadNextValue override from LambdaReader (base class handles it)

Author: arhamchopra

cpp/csp/adapters/arrow/ArrowFieldReader.h

@@ -190,15 +190,6 @@ class LambdaReader final : public TypedFieldReader<ValueT>
         return false;
     }
 
-    void doReadNextValue( int64_t row, void * optionalOut ) override
-    {
-        auto & out = *static_cast<std::optional<ValueT> *>( optionalOut );
-        auto & typed = static_cast<const ArrowArrayT &>( *this -> m_column );
-        if( typed.IsValid( row ) )
-            out = m_extractFn( typed, row );
-        else
-            out.reset();
-    }
 
 private:
     ExtractFn  m_extractFn;

cpp/csp/adapters/arrow/ColumnDispatcher.cpp

@@ -181,7 +181,7 @@ std::unique_ptr<ColumnDispatcher> createColumnDispatcher(
 {
     auto typeId = arrowField -> type() -> id();
     auto & name = arrowField -> name();
-    auto viewToString = []( const auto & arr, int64_t i ) -> std::string {
+    static auto viewToString = []( const auto & arr, int64_t i ) -> std::string {
         auto view = arr.GetView( i );
         return std::string( view.data(), view.size() );
     };

cpp/csp/adapters/parquet/ParquetInputAdapterManager.cpp

@@ -189,16 +189,16 @@ ParquetInputAdapterManager::ParquetInputAdapterManager( csp::Engine *engine, con
 
     m_symbolColumn        = properties.get<std::string>( "symbol_column", "" );
     m_timeColumn          = properties.get<std::string>( "time_column", "" );
-    m_defaultTimezone     = properties.get<std::string>( "tz", "UTC" );
+    auto tz = properties.get<std::string>( "tz", "UTC" );
+    CSP_TRUE_OR_THROW_RUNTIME( tz == "UTC",
+                               "Only UTC default timezone is supported, got:" << tz );
     m_allowOverlappingPeriods = properties.get<bool>( "allow_overlapping_periods", false );
     m_allowMissingColumns = properties.get<bool>( "allow_missing_columns", false );
     properties.tryGet( "start_time", m_startTime );
     properties.tryGet( "end_time", m_endTime );
     properties.tryGet( "time_shift", m_time_shift );
 
     CSP_TRUE_OR_THROW_RUNTIME( m_timeColumn != "", "Time column can't be empty" );
-    CSP_TRUE_OR_THROW_RUNTIME( m_defaultTimezone == "UTC",
-                               "Only UTC default timezone is supported, got:" << m_defaultTimezone );
 }
 
 ParquetInputAdapterManager::~ParquetInputAdapterManager() = default;

cpp/csp/adapters/parquet/ParquetInputAdapterManager.h

@@ -166,7 +166,6 @@ class ParquetInputAdapterManager final : public csp::AdapterManager
     RecordBatchStreamSourcePtr          m_streamSource;
     std::string                         m_symbolColumn;
     std::string                         m_timeColumn;
-    std::string                         m_defaultTimezone;
     bool                                m_allowOverlappingPeriods;
     bool                                m_allowMissingColumns;
     std::optional<PushMode>             m_pushMode;