The parameters for RPC GET requests are parsed from query arguments in the
request URL. Rework this code to remove the need for tmjson. The structure of a
call still requires reflection, and still works the same way as before, but the
code structure has been simplified and cleaned up a bit.
Points of note:
- Consolidate handling of pointer types, so we only need to dereference once.
- Reduce the number of allocations of reflective types.
- Report errors for unsupported types rather than returning untyped nil.
Update the tests as well. There was one test case that checked for an error on
a behaviour the OpenAPI docs explicitly demonstrates as supported, so I fixed
that test case, and also added some new ones for cases that weren't checked.
Related:
* Update e2e base Go image to 1.17 (to match config).
Require that RPC functions take a context as their first argument, and return
an error as either their only result, or the second of two results.
This does not change how functions are dispatched, but will make it a little
easier to make more invasive changes in the near future.
Instead of taking a comma-separated string of parameter names, take each
parameter name as a separate argument. Now that we no longer have an extra flag
for caching, this fits nicely into a variadic trailer.
* Update all usage of NewRPCFunc and NewWSRPCFunc.
We should not set cache-control headers on RPC responses. HTTP caching
interacts poorly with resources that are expected to change frequently, or
whose rate of change is unpredictable.
More subtly, all calls to the POST endpoint use the same URL, which means a
cacheable response from one call may actually "hide" an uncacheable response
from a subsequent one. This is less of a problem for the GET endpoints, but
that means the behaviour of RPCs varies depending on which HTTP method your
client happens to use. Websocket requests were already marked statically
uncacheable, adding yet a third combination.
To address this:
- Stop setting cache-control headers.
- Update the tests that were checking for those headers.
- Remove the flags to request cache-control.
Apart from affecting the HTTP response headers, this change does not modify the
behaviour of any of the RPC methods.
* Rename rpctypes.Context to CallInfo.
Add methods to attach and recover this value from a context.Context.
* Rework RPC method handlers to accept "real" contexts.
- Replace *rpctypes.Context arguments with context.Context.
- Update usage of RPC context fields to use CallInfo.
The code in the Tendermint repository makes heavy use of import aliasing.
This is made necessary by our extensive reuse of common base package names, and
by repetition of similar names across different subdirectories.
Unfortunately we have not been very consistent about which packages we alias in
various circumstances, and the aliases we use vary. In the spirit of the advice
in the style guide and https://github.com/golang/go/wiki/CodeReviewComments#imports,
his change makes an effort to clean up and normalize import aliasing.
This change makes no API or behavioral changes. It is a pure cleanup intended
o help make the code more readable to developers (including myself) trying to
understand what is being imported where.
Only unexported names have been modified, and the changes were generated and
applied mechanically with gofmt -r and comby, respecting the lexical and
syntactic rules of Go. Even so, I did not fix every inconsistency. Where the
changes would be too disruptive, I left it alone.
The principles I followed in this cleanup are:
- Remove aliases that restate the package name.
- Remove aliases where the base package name is unambiguous.
- Move overly-terse abbreviations from the import to the usage site.
- Fix lexical issues (remove underscores, remove capitalization).
- Fix import groupings to more closely match the style guide.
- Group blank (side-effecting) imports and ensure they are commented.
- Add aliases to multiple imports with the same base package name.
Migrates the `rpc` package to use new JSON encoder in #4955. Branched off of that PR.
Tests pass, but I haven't done any manual testing beyond that. This should be handled as part of broader 0.34 testing.
