On Fri, May 1, 2020 at 1:53 PM James Coleman <jtc...@gmail.com> wrote: > In another thread [1] I'd mused that "there might be some value in a > README or comments > addition that would be a guide to what the various hash > implementations are useful for...so that we have something to make the > code base a bit more discoverable."
+1 > I'd solicited feedback from Andres (as the author of the simplehash > implementation) and gotten further explanation from Tomas (both cc'd > here) and have tried to condense that into the comment changes in this > patch series. > > v1-0001-Summarize-trade-offs-between-simplehash-and-dynah.patch > Contains the summaries mentioned above. + * - It supports partitioning, which is useful for shared memory access using I wonder if we should say a bit more about the shared memory mode. Shared memory dynahash tables are allocated in a fixed size area at startup, and are discoverable by name in other other processes that need to get access to them, while simplehash assumes that it can get memory from a MemoryContext or an allocator with a malloc/free-style interface, which isn't very well suited for use in shared memory. (I'm sure you can convince it to work in shared memory with some work.) > v1-0002-Improve-simplehash-usage-notes.patch + * For convenience the hash table create functions accept a void pointer + * will be stored in the hash table type's member private_data. *that* will be stored? > v1-0003-Show-sample-simplehash-method-signatures.patch > I find it hard to read the macro code "templating" particularly for > seeing what the available API is and so added sample method signatures > in comments to the macro generated method signature defines. I didn't double-check all the expansions of the macros but +1 for this idea, it's very useful.
