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.
Closes#4603
Commands used (VIM):
```
:args `rg -l errors.Wrap`
:argdo normal @q | update
```
where q is a macros rewriting the `errors.Wrap` to `fmt.Errorf`.
https://www.jsonrpc.org/specification
What is done in this PR:
JSONRPCClient: validate that Response.ID matches Request.ID I wanted
to do the same for the WSClient, but since we're sending events as
responses, not notifications, checking IDs would require storing
them in memory indefinitely (and we won't be able to remove them
upon client unsubscribing because ID is different then).
Request.ID is now optional. Notification is a Request without an ID.
Previously "" or 0 were considered as notifications
Remove #event suffix from ID from an event response (partially fixes
#2949) ID must be either string, int or null AND must be equal to
request's ID. Now, because we've implemented events as responses, WS
clients are tripping when they see Response.ID("0#event") !=
Request.ID("0"). Implementing events as requests would require a lot
of time (~ 2 days to completely rewrite WS client and server)
generate unique ID for each request
switch to integer IDs instead of "json-client-XYZ"
id=0 method=/subscribe
id=0 result=...
id=1 method=/abci_query
id=1 result=...
> send events (resulting from /subscribe) as requests+notifications (not
responses)
this will require a lot of work. probably not worth it
* rpc: generate an unique ID for each request
in conformance with JSON-RPC spec
* WSClient: check for unsolicited responses
* fix golangci warnings
* save commit
* fix errors
* remove ID from responses from subscribe
Refs #2949
* clients are safe for concurrent access
* tm-bench: switch to int ID
* fixes after my own review
* comment out sentIDs in WSClient
see commit body for the reason
* remove body.Close
it will be closed automatically
* stop ws connection outside of write/read routines
also, use t.Rate in tm-bench indexer when calculating ID
fix gocritic issues
* update swagger.yaml
* Apply suggestions from code review
* fix stylecheck and golint linter warnings
* update changelog
* update changelog2
M. J. Fromberger
Sharad Chand
Sam Kleinman
Callum Waters
JayT106
Anton Kaliaev
Marko
Aleksandr Bezobchuk
Bipul Prasad
Erik Grinaker