gotosocial/internal/log/format/format.go
kim 7af9117e0d [feature + performance] add JSON logging format (#4355)
# Description

Adds JSON logging as an optional alternative log output format. In the process this moves our log formatting itself into a separate subpkg to make it more easily modular, and improves caller name getting with some calling function name caching.

## Checklist

- [x] I/we have read the [GoToSocial contribution guidelines](https://codeberg.org/superseriousbusiness/gotosocial/src/branch/main/CONTRIBUTING.md).
- [x] I/we have discussed the proposed changes already, either in an issue on the repository, or in the Matrix chat.
- [x] I/we have not leveraged AI to create the proposed changes.
- [x] I/we have performed a self-review of added code.
- [x] I/we have written code that is legible and maintainable by others.
- [x] I/we have commented the added code, particularly in hard-to-understand areas.
- [x] I/we have made any necessary changes to documentation.
- [ ] I/we have added tests that cover new code.
- [x] I/we have run tests and they pass locally with the changes.
- [x] I/we have run `go fmt ./...` and `golangci-lint run`.

Reviewed-on: https://codeberg.org/superseriousbusiness/gotosocial/pulls/4355
Co-authored-by: kim <grufwub@gmail.com>
Co-committed-by: kim <grufwub@gmail.com>
2025-08-09 16:23:00 +02:00

90 lines
2.8 KiB
Go

// GoToSocial
// Copyright (C) GoToSocial Authors admin@gotosocial.org
// SPDX-License-Identifier: AGPL-3.0-or-later
//
// This program is free software: you can redistribute it and/or modify
// it under the terms of the GNU Affero General Public License as published by
// the Free Software Foundation, either version 3 of the License, or
// (at your option) any later version.
//
// This program is distributed in the hope that it will be useful,
// but WITHOUT ANY WARRANTY; without even the implied warranty of
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
// GNU Affero General Public License for more details.
//
// You should have received a copy of the GNU Affero General Public License
// along with this program. If not, see <http://www.gnu.org/licenses/>.
package format
import (
"sync/atomic"
"time"
"code.superseriousbusiness.org/gotosocial/internal/log/level"
"codeberg.org/gruf/go-byteutil"
"codeberg.org/gruf/go-kv/v2"
)
var (
// ensure func signature conformance.
_ FormatFunc = (*Logfmt)(nil).Format
_ FormatFunc = (*JSON)(nil).Format
)
// FormatFunc defines a function capable of formatting a log entry (args = 1+) to a given buffer (args = 0).
type FormatFunc func(buf *byteutil.Buffer, stamp time.Time, pc uintptr, lvl level.LEVEL, kvs []kv.Field, msg string) //nolint:revive
type Base struct {
// TimeFormat defines time.Format() layout to
// use when appending a timestamp to log entry.
TimeFormat string
// stampCache caches recently formatted stamps.
//
// see the following benchmark:
// goos: linux
// goarch: amd64
// pkg: code.superseriousbusiness.org/gotosocial/internal/log/format
// cpu: AMD Ryzen 7 7840U w/ Radeon 780M Graphics
// BenchmarkStampCache
// BenchmarkStampCache-16 272199975 4.447 ns/op 0 B/op 0 allocs/op
// BenchmarkNoStampCache
// BenchmarkNoStampCache-16 76041058 15.94 ns/op 0 B/op 0 allocs/op
stampCache atomic.Pointer[struct {
stamp time.Time
format string
}]
}
// AppendFormatStamp will append given timestamp according to TimeFormat,
// caching recently formatted stamp strings to reduce number of Format() calls.
func (b *Base) AppendFormatStamp(buf *byteutil.Buffer, stamp time.Time) {
const precision = time.Millisecond
// Load cached stamp value.
last := b.stampCache.Load()
// Round stamp to min precision.
stamp = stamp.Round(precision)
// If a cached entry exists use this string.
if last != nil && stamp.Equal(last.stamp) {
buf.B = append(buf.B, last.format...)
return
}
// Else format new and store ASAP,
// i.e. ignoring any CAS result.
format := stamp.Format(b.TimeFormat)
b.stampCache.CompareAndSwap(last, &struct {
stamp time.Time
format string
}{
stamp: stamp,
format: format,
})
// Finally, append new timestamp.
buf.B = append(buf.B, format...)
}