[ https://issues.apache.org/jira/browse/THRIFT-1188?page=com.atlassian.jira.plugin.system.issuetabpanels:all-tabpanel ]
Jake Farrell updated THRIFT-1188: --------------------------------- Component/s: C++ - Compiler > C++: Use bit fields for a more compact __isset struct > ----------------------------------------------------- > > Key: THRIFT-1188 > URL: https://issues.apache.org/jira/browse/THRIFT-1188 > Project: Thrift > Issue Type: New Feature > Components: C++ - Compiler > Affects Versions: 0.6.1, 0.7 > Reporter: Eric Rannaud > Attachments: thrift-cpp-isset-bitfield.patch > > > With the C++ generator, the __isset structure is made of bool fields. > For Thrift objects with many optional fields, the memory impact of the > __isset structure with respect to the actual data payload can be significant. > This patch simply turns each member of __isset into a 1-bit field. > This patch does not pack the structure as I'm not sure how this should be > handled in general. As is, it will depend on the compiler whether there is a > real size gain (with GCC 4.5 the struct is packed at all optimization levels). > To enforce packing in all cases, should I define a T_ATTRIBUTE_PACKED macro > in Thrift.h? That wouldn't work for compilers that use #pragma, however. -- This message is automatically generated by JIRA. If you think it was sent incorrectly, please contact your JIRA administrators For more information on JIRA, see: http://www.atlassian.com/software/jira