[VOL-4291] Rw-core updates for gRPC migration
Change-Id: I8d5a554409115b29318089671ca4e1ab3fa98810
diff --git a/vendor/go.uber.org/zap/zapcore/sampler.go b/vendor/go.uber.org/zap/zapcore/sampler.go
index e316418..25f10ca 100644
--- a/vendor/go.uber.org/zap/zapcore/sampler.go
+++ b/vendor/go.uber.org/zap/zapcore/sampler.go
@@ -81,17 +81,92 @@
return 1
}
+// SamplingDecision is a decision represented as a bit field made by sampler.
+// More decisions may be added in the future.
+type SamplingDecision uint32
+
+const (
+ // LogDropped indicates that the Sampler dropped a log entry.
+ LogDropped SamplingDecision = 1 << iota
+ // LogSampled indicates that the Sampler sampled a log entry.
+ LogSampled
+)
+
+// optionFunc wraps a func so it satisfies the SamplerOption interface.
+type optionFunc func(*sampler)
+
+func (f optionFunc) apply(s *sampler) {
+ f(s)
+}
+
+// SamplerOption configures a Sampler.
+type SamplerOption interface {
+ apply(*sampler)
+}
+
+// nopSamplingHook is the default hook used by sampler.
+func nopSamplingHook(Entry, SamplingDecision) {}
+
+// SamplerHook registers a function which will be called when Sampler makes a
+// decision.
+//
+// This hook may be used to get visibility into the performance of the sampler.
+// For example, use it to track metrics of dropped versus sampled logs.
+//
+// var dropped atomic.Int64
+// zapcore.SamplerHook(func(ent zapcore.Entry, dec zapcore.SamplingDecision) {
+// if dec&zapcore.LogDropped > 0 {
+// dropped.Inc()
+// }
+// })
+func SamplerHook(hook func(entry Entry, dec SamplingDecision)) SamplerOption {
+ return optionFunc(func(s *sampler) {
+ s.hook = hook
+ })
+}
+
+// NewSamplerWithOptions creates a Core that samples incoming entries, which
+// caps the CPU and I/O load of logging while attempting to preserve a
+// representative subset of your logs.
+//
+// Zap samples by logging the first N entries with a given level and message
+// each tick. If more Entries with the same level and message are seen during
+// the same interval, every Mth message is logged and the rest are dropped.
+//
+// Sampler can be configured to report sampling decisions with the SamplerHook
+// option.
+//
+// Keep in mind that zap's sampling implementation is optimized for speed over
+// absolute precision; under load, each tick may be slightly over- or
+// under-sampled.
+func NewSamplerWithOptions(core Core, tick time.Duration, first, thereafter int, opts ...SamplerOption) Core {
+ s := &sampler{
+ Core: core,
+ tick: tick,
+ counts: newCounters(),
+ first: uint64(first),
+ thereafter: uint64(thereafter),
+ hook: nopSamplingHook,
+ }
+ for _, opt := range opts {
+ opt.apply(s)
+ }
+
+ return s
+}
+
type sampler struct {
Core
counts *counters
tick time.Duration
first, thereafter uint64
+ hook func(Entry, SamplingDecision)
}
-// NewSampler creates a Core that samples incoming entries, which caps the CPU
-// and I/O load of logging while attempting to preserve a representative subset
-// of your logs.
+// NewSampler creates a Core that samples incoming entries, which
+// caps the CPU and I/O load of logging while attempting to preserve a
+// representative subset of your logs.
//
// Zap samples by logging the first N entries with a given level and message
// each tick. If more Entries with the same level and message are seen during
@@ -100,14 +175,10 @@
// Keep in mind that zap's sampling implementation is optimized for speed over
// absolute precision; under load, each tick may be slightly over- or
// under-sampled.
+//
+// Deprecated: use NewSamplerWithOptions.
func NewSampler(core Core, tick time.Duration, first, thereafter int) Core {
- return &sampler{
- Core: core,
- tick: tick,
- counts: newCounters(),
- first: uint64(first),
- thereafter: uint64(thereafter),
- }
+ return NewSamplerWithOptions(core, tick, first, thereafter)
}
func (s *sampler) With(fields []Field) Core {
@@ -117,6 +188,7 @@
counts: s.counts,
first: s.first,
thereafter: s.thereafter,
+ hook: s.hook,
}
}
@@ -128,7 +200,9 @@
counter := s.counts.get(ent.Level, ent.Message)
n := counter.IncCheckReset(ent.Time, s.tick)
if n > s.first && (n-s.first)%s.thereafter != 0 {
+ s.hook(ent, LogDropped)
return ce
}
+ s.hook(ent, LogSampled)
return s.Core.Check(ent, ce)
}