minio/internal/bucket/bandwidth/reader.go
Harshavardhana 1f262daf6f
rename all remaining packages to internal/ (#12418)
This is to ensure that there are no projects
that try to import `minio/minio/pkg` into
their own repo. Any such common packages should
go to `https://github.com/minio/pkg`
2021-06-01 14:59:40 -07:00

81 lines
2.5 KiB
Go

// Copyright (c) 2015-2021 MinIO, Inc.
//
// This file is part of MinIO Object Storage stack
//
// 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 bandwidth
import (
"context"
"io"
)
// MonitoredReader monitors the bandwidth
type MonitoredReader struct {
opts *MonitorReaderOptions
bucketMeasurement *bucketMeasurement // bucket measurement object
reader io.Reader // Reader to wrap
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 {
return &MonitoredReader{
opts: opts,
bucketMeasurement: monitor.track(opts.Bucket, opts.Object),
reader: reader,
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)
if err != nil {
m.lastErr = err
}
update := n + m.opts.HeaderSize
unused := len(p) - update
m.bucketMeasurement.incrementBytes(uint64(update))
m.opts.HeaderSize = 0 // Set to 0 post first read
if unused > 0 {
m.throttle.ReleaseUnusedBandwidth(int64(unused))
}
return
}