minio/pkg/bucket/bandwidth/reader.go
Harshavardhana c608c0688a fix: properly close leaking bandwidth monitor channel (#11967)
This PR fixes

- close leaking bandwidth report channel leakage
- remove the closer requirement for bandwidth monitor
  instead if Read() fails remember the error and return
  error for all subsequent reads.
- use locking for usage-cache.bin updates, with inline
  data we cannot afford to have concurrent writes to
  usage-cache.bin corrupting xl.meta
2021-04-06 12:40:42 -07:00

86 lines
2.6 KiB
Go

/*
* MinIO Cloud Storage, (C) 2020 MinIO, Inc.
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*
*/
package bandwidth
import (
"context"
"io"
"time"
)
// MonitoredReader monitors the bandwidth
type MonitoredReader struct {
opts *MonitorReaderOptions
bucketMeasurement *bucketMeasurement // bucket measurement object
reader io.Reader // Reader to wrap
lastStop time.Time // Last timestamp for a measurement
throttle *throttle // throttle the rate at which replication occur
monitor *Monitor // Monitor reference
lastErr error // last error reported, if this non-nil all reads will fail.
}
// MonitorReaderOptions provides configurable options for monitor reader implementation.
type MonitorReaderOptions struct {
Bucket string
Object string
HeaderSize int
BandwidthBytesPerSec int64
ClusterBandwidth int64
}
// NewMonitoredReader returns a io.Reader that reports bandwidth details.
func NewMonitoredReader(ctx context.Context, monitor *Monitor, reader io.Reader, opts *MonitorReaderOptions) *MonitoredReader {
timeNow := time.Now()
b := monitor.track(opts.Bucket, opts.Object, timeNow)
return &MonitoredReader{
opts: opts,
bucketMeasurement: b,
reader: reader,
lastStop: timeNow,
throttle: monitor.throttleBandwidth(ctx, opts.Bucket, opts.BandwidthBytesPerSec, opts.ClusterBandwidth),
monitor: monitor,
}
}
// Read wraps the read reader
func (m *MonitoredReader) Read(p []byte) (n int, err error) {
if m.lastErr != nil {
err = m.lastErr
return
}
p = p[:m.throttle.GetLimitForBytes(int64(len(p)))]
n, err = m.reader.Read(p)
stop := time.Now()
update := uint64(n + m.opts.HeaderSize)
m.bucketMeasurement.incrementBytes(update)
m.lastStop = stop
unused := len(p) - (n + m.opts.HeaderSize)
m.opts.HeaderSize = 0 // Set to 0 post first read
if unused > 0 {
m.throttle.ReleaseUnusedBandwidth(int64(unused))
}
if err != nil {
m.lastErr = err
}
return
}