bwilliams
67215a6aaa
CODE_CONVENTIONS.md sets out the conventions for Go code in this repository: naming, layout, comments, errors, logging, configuration and tests. .golangci.json enables the linters that check the parts that can be checked (each limited to the rules the conventions use); the rest is applied by hand. Applied across the codebase: - Naming: full-word names in application code, initialisms in one case (BuyerID, PrintJSON, PrintYAML, ocdsGetBuyerID), no names shadowing built-ins (min/max are minGap/maxGap), mustRaw renamed rawJSON as it returns nil rather than panicking, and config.ConfigLevelToLogLevel renamed LevelToLogLevel. - Layout: lines kept to 80 characters where possible, assignments taken out of if and for statements that don't fit, wrapped arguments all on one line or one per line, steps separated by blank lines, no else after a return, function and struct literals wrapped. - Comments: doc comments on every exported name (including each section's Map, Flatten, TypeOf, ValueOf and SetValue), section banners, British spelling. - Errors: a created error starts with its package name, a wrapping error adds only what was being done, sentinels in one commented var block, errors.Is and errors.As in place of == and type assertions, and no err := shadowing of a named result. That fixes the mock server losing its access log's close error. - Logging: the fetcher passes its workers an untagged logger, so findatender's lines are tagged with their own component rather than with fetcher's as well; cmd/mock-fts logs "stopped" with slog. - Configuration: util.WithTimeout (moved from the websocket package) applies a timeout of 0 or less as no limit, used for the websocket write and ping, TCP close and tcpserver shutdown timeouts; every setting documents what 0 or empty means, including the rate limit rule's keys in internal/config/README.md. - Tests: related tests merged into table-driven ones with named cases. Separately from CODE_CONVENTIONS.md, internal/store/README.md gains a soft SQL style convention for the queries in internal/store/queries.go, and the queries are reformatted to follow it.
74 lines
2.3 KiB
Go
74 lines
2.3 KiB
Go
// Package websocket implements the hub that pushes messages to connected
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// clients: WebSocket clients upgraded by Hub.ServeHTTP (the /ws endpoint) and
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// plain TCP clients run by Hub.ServeTCP, which send the same messages as
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// newline-delimited JSON (see tcp.go). Package tcpserver runs a TCP server
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// for those clients.
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//
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// Every message is a JSON Envelope: a WebSocket text frame, or one line on
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// TCP.
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//
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// Client -> server:
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//
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// {"type":"ping","id":"1"}
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// {"type":"echo","id":"2","payload":{...}}
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//
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// Server -> client:
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//
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// {"type":"welcome","payload":{"clientId":"..."}}
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// {"type":"pong","id":"1","payload":{"time":"..."}}
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// {"type":"echo","id":"2","payload":{...}}
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// {"type":"error","id":"3","error":"..."}
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// {"type":"item.created","payload":{...}}
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//
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// Any other type from a client gets an "unknown message type" error. The last
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// message is one sent by Hub.Push: its type is the pushed message type.
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package websocket
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import "encoding/json"
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// Envelope is the wire format for every message in both directions.
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type Envelope struct {
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Type string `json:"type"`
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ID string `json:"id,omitempty"`
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Payload json.RawMessage `json:"payload,omitempty"`
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Error string `json:"error,omitempty"`
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}
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// Envelope types. TypeEvent, TypeRequest and TypeAck are reserved: nothing
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// sends or handles them yet.
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const (
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// TypeWelcome is sent to a client when it connects, with its client ID.
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TypeWelcome = "welcome"
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// TypePing asks the server for a TypePong.
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TypePing = "ping"
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// TypePong answers a TypePing, with the server's time.
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TypePong = "pong"
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// TypeEcho is sent back to the client with the same ID and payload.
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TypeEcho = "echo"
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// TypeEvent is reserved for events pushed to clients.
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TypeEvent = "event"
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// TypeRequest is reserved for requests from clients.
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TypeRequest = "request"
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// TypeAck is reserved for acknowledging a request.
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TypeAck = "ack"
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// TypeError reports an error, with the ID of the message it answers.
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TypeError = "error"
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)
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// rawJSON returns value as raw JSON: value itself if it is already
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// json.RawMessage, nil if value is nil or can't be marshalled.
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func rawJSON(value any) json.RawMessage {
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if value == nil {
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return nil
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}
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if raw, ok := value.(json.RawMessage); ok {
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return raw
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}
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encoded, err := json.Marshal(value)
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if err != nil {
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return nil
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}
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return encoded
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}
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