github.com/matrixorigin/matrixone@v1.2.0/pkg/common/log/filter.go (about)

     1  // Copyright 2022 Matrix Origin
     2  //
     3  // Licensed under the Apache License, Version 2.0 (the "License");
     4  // you may not use this file except in compliance with the License.
     5  // You may obtain a copy of the License at
     6  //
     7  //      http://www.apache.org/licenses/LICENSE-2.0
     8  //
     9  // Unless required by applicable law or agreed to in writing, software
    10  // distributed under the License is distributed on an "AS IS" BASIS,
    11  // WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
    12  // See the License for the specific language governing permissions and
    13  // limitations under the License.
    14  
    15  package log
    16  
    17  import (
    18  	"sync/atomic"
    19  )
    20  
    21  var (
    22  	// all log filters register here.
    23  	filters = []logFilter{sampleFilter}
    24  
    25  	// all SampleType register here.
    26  	samples = map[SampleType]*sampleValue{
    27  		ExampleSample:    {frequency: 3},
    28  		SystemInitSample: {frequency: 5},
    29  	}
    30  )
    31  
    32  func sampleFilter(opts LogOptions) bool {
    33  	if opts.sampleType == noneSample {
    34  		return true
    35  	}
    36  	if v, ok := samples[opts.sampleType]; ok {
    37  		return v.allow()
    38  	}
    39  	return false
    40  }
    41  
    42  type sampleValue struct {
    43  	v         uint64
    44  	frequency uint64
    45  }
    46  
    47  func (s *sampleValue) allow() bool {
    48  	n := s.incr()
    49  	return n == 1 || n%s.frequency == 0
    50  }
    51  
    52  func (s *sampleValue) incr() uint64 {
    53  	return atomic.AddUint64(&s.v, 1)
    54  }