* rpc: fix layout of endpoint list
The output of the default endpoint-list query was not correctly segregating
methods with and without arguments. Fix this, and also clean up the output to
be easier to read (both in code and in generated source).
Fixes#3618.
* rpc: simplify the handling of JSON-RPC request and response IDs
Replace the ID wrapper interface with plain JSON. Internally, the client
libraries use only integer IDs, and the server does not care about the ID
structure apart from checking its validity.
Basic structure of this change:
- Remove the jsonrpcid interface and its helpers.
- Unexport the ID field of request and response.
- Add helpers for constructing requests and responses.
- Fix up usage and tests.
Responses are constructed from requests using MakeResponse, MakeError, and
MakeErrorf. This ensures the response is always paired with the correct ID,
makes cases where there is no ID more explicit at the usage site, and
consolidates the handling of error introspection across transports.
The logic for unpacking errors and assigning JSON-RPC response types was
previously duplicated in three places. Consolidate it in the types package for
the RPC subsystem.
* update test cases
The main change here is to use encoding/json to encode and decode RPC
parameters, rather than the custom tmjson package. This includes:
- Update the HTTP POST handler parameter handling.
- Add field tags to 64-bit integer types to get string encoding (to match amino/tmjson).
- Add marshalers to struct types that mention interfaces.
- Inject wrappers to decode interface arguments in RPC handlers.
Add writeRPCResponse and writeHTTPResponse helpers, that handle the way RPC
responses are written to HTTP replies. These replace the exported helpers.
Visible effects:
- JSON results are now marshaled without indentation.
- HTTP status codes are now normalized.
- Cache control headers are no longer set.
Details:
- When writing a response to a URL (GET) request, do not marshal the whole
JSON-RPC object into the body, only encode the result or the error object.
This is a user-visible change.
- Do not change the HTTP status code for RPC errors. The RPC error already
reports what went wrong, the HTTP status should only report problems with the
HTTP transaction itself. This is a user-visible change.
- Encode JSON without indentation in POST response bodies. This is mainly cosmetic
but saves quite a bit of response data. Indent is still applied to GET responses to make
life easier for code examples.
- Remove an obsolete TODO about reporting an HTTP error on websocket upgrade.
Nothing needed to change; the upgrader already reports an error.
- Report an HTTP error when starting the server loop fails.
- Improve logging for encoding errors.
- Log less aggressively.
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.
No functional changes.
- Pull out a some helper code to simplify the control flow within the body of
the HTTP request handler.
- Front-load the URL path check so it does not get repeated for each request.
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.
