I dont know full details of Cap'n Proto, so please correct me if I am wrong. My impression is that Cap'n Proto is a re-implementation of protocol buffers with additional functionality for RPC wrapped in a futures/promises abstraction. Would that be a reasonable summary of Cap'n Proto ?
Guessing from the name I expected FlatBuffers to be a unified file format for on-disk and on-RAM presence, so that you can just mmap the disk file and you have the data-structure in memory. No need to translate between on disk and on disk representations. I am not claiming that it is so, this is what I expected it to be, given the name. But after spending some time looking around I am still confused if that's what it is. Would appreciate confirmation either way. Have to look at the code when I get around to it.
I have an use case in mind for a tree of appendable/insertable matrices. HDf5 comes close, but isnt quite what I am looking for.
EDIT @vertex-four thanks for the clarification much appreciated.
> My impression is that Cap'n Proto is a re-implementation of protocol buffers with additional functionality for RPC wrapped in a futures/promises abstraction.
No. It's a serialisation format that's specifically designed so that data structures in this format can be used as-is by programs, without unnecessarily copying data into or out of the format to use it. The RPC layer is then built on top of that, but the format could also be used for mmapped files, etc.
They are compiled as separate libraries, so you can use the serialization layer without linking in the RPC layer.
But if anything it was the serialization that distracted me from the RPC. Cap'n Proto was originally (briefly) a capability-based RPC system on top of Protobufs. :)
Guessing from the name I expected FlatBuffers to be a unified file format for on-disk and on-RAM presence, so that you can just mmap the disk file and you have the data-structure in memory. No need to translate between on disk and on disk representations. I am not claiming that it is so, this is what I expected it to be, given the name. But after spending some time looking around I am still confused if that's what it is. Would appreciate confirmation either way. Have to look at the code when I get around to it.
I have an use case in mind for a tree of appendable/insertable matrices. HDf5 comes close, but isnt quite what I am looking for.
EDIT @vertex-four thanks for the clarification much appreciated.