[ARROW-8661] [C++][Gandiva] Reduce number of files and headers

• Type: Improvement
• Status: Open
• Priority: Major
• Resolution: Unresolved
• Component/s: C++, C++ - Gandiva
• External issue URL: https://github.com/apache/arrow/issues/24822
• Assignee: Unassigned
• Reporter: Wes McKinney
• Created: 01/May/20 01:59
• Updated: 11/Jan/23 08:01

Description

I feel that the Gandiva subpackage is more Java-like in its code organization than the rest of the Arrow codebase, and it might be easier to navigate and develop with closely related code condensed into some larger headers and compilation units. At present there are over 100 .h/.cc files in just src/gandiva, not considering subdirectories

Additionally, it's not necessary to have a header file for each component of the function registry – the registration functions can be declared in function_registry.h or function_registry_internal.h