Christian Schwarz
1ae087bfcf
- make `logging.GetLogger(ctx, Subsys)` the authoritative `logger.Logger` factory function
- the context carries a linked list of injected fields which
`logging.GetLogger` adds to the logger it returns
- introduce the concept of tasks and spans, also tracked as linked list within ctx
- [ ] TODO automatic logging of span begins and ends, with a unique
ID stack that makes it easy to follow a series of log entries in
concurrent code
- ability to produce a chrome://tracing-compatible trace file,
either via an env variable or a `zrepl pprof` subcommand
- this is not a CPU profile, we already have go pprof for that
- but it is very useful to visually inspect where the
replication / snapshotter / pruner spends its time
( fixes #307 )
27 lines
474 B
Go
27 lines
474 B
Go
package logging
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import "context"
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type contextKey int
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const (
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contextKeyTraceNode contextKey = 1 + iota
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contextKeyLoggers
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contextKeyInjectedField
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)
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var contextKeys = []contextKey{
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contextKeyTraceNode,
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contextKeyLoggers,
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contextKeyInjectedField,
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}
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func WithInherit(ctx, inheritFrom context.Context) context.Context {
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for _, k := range contextKeys {
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if v := inheritFrom.Value(k); v != nil {
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ctx = context.WithValue(ctx, k, v) // no shadow
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}
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}
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return ctx
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}
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