Chiebot-Mirror/protobuf - protobuf - Gitea: Git with a cup of tea

Author	SHA1	Message	Date
Joshua Haberman	d22d6d71ed	Refactored message accessors to share a common set of functions instead of duplicating logic. Prior to this CL, there were several different code paths for reading/writing message data. Generated code, MiniTable accessors, and reflection all performed direct manipulation of the bits and bytes in a message, but they all had distinct implementations that did not share much of any code. This divergence meant that they could easily have different behavior, bugs could creep into one but not another, and we would need three different sets of tests to get full test coverage. This also made it very difficult to change the internal representation in any way, since it would require updating many places in the code. With this CL, the three different APIs for accessing message data now all share a common set of functions. The common functions all take a `upb_MiniTableField` as the canonical description of a field's type and layout. The lowest-level functions are very branchy, as they must test for every possible variation in the field type (field vs oneof, hasbit vs no-hasbit, different field sizes, whether a nonzero default value exists, extension vs. regular field), however these functions are declared inline and designed to be very optimizable when values are known at compile time. In generated accessors, for example, we can declare constant `upb_MiniTableField` instances so that all values can constant-propagate, and we can get fully specialized code even though we are calling a generic function. On the other hand, when we use the generic functions from reflection, we get runtime branches since values are not known at compile time. But even the function is written to still be as efficient as possible even when used from reflection. For example, we use memcpy() calls with constant length so that the compiler can optimize these into inline loads/stores without having to make an out-of-line call to memcpy(). In this way, this CL should be a benefit to both correctness and performance. It will also make it easier to change the message representation, for example to optimize the encoder by giving hasbits to all fields. Note that we have not completely consolidated all access in this CL: 1. Some functions outside of get/set such as clear and hazzers are not yet unified. 2. The encoder and decoder still touch the message without going through the common functions. The encoder and decoder require a bit more specialized code to get good performance when reading/writing fields en masse. PiperOrigin-RevId: 490016095	2 years ago
Eric Salo	27d70edfe2	clean up the :mini_table build target Remove circular dependencies that were bouncing back and forth between msg_internal.h and mini_table/, including: - splitting out each mini table subtype into its own header - moving the non-reflection message code into message/ - moving the accessors from mini_table/ to message/ PiperOrigin-RevId: 489121042	2 years ago
Eric Salo	33633fd604	generated code now uses the scalar get accessors Also tweaked the generator to only emit a call to UPB_SIZE() when the two input values are actually different. PiperOrigin-RevId: 487606926	2 years ago
Eric Salo	75907f7af9	rename the upb_MiniTable subtypes to follow the upb style guide: upb_MiniTable_Enum -> upb_MiniTableEnum upb_MiniTable_Extension -> upb_MiniTableExtension upb_MiniTable_Field -> upb_MiniTableField upb_MiniTable_File -> upb_MiniTableFile upb_MiniTable_Sub -> upb_MiniTableSub PiperOrigin-RevId: 486712960	2 years ago
Eric Salo	d9b6f13cde	remove upb_MtDataEncoder from the public surface PiperOrigin-RevId: 485928803	2 years ago
Eric Salo	5c646803ef	implement mini descriptors for message sets PiperOrigin-RevId: 484058392	2 years ago
Eric Salo	20310e2f3a	implement mini descriptors for maps PiperOrigin-RevId: 483474044	2 years ago
Protobuf Team Bot	46e306bead	Move generator shared support code to common target. PiperOrigin-RevId: 458257330	2 years ago