mirror of https://github.com/minio/minio.git
61 lines
1.8 KiB
Go
61 lines
1.8 KiB
Go
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/*
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* Minio Cloud Storage, (C) 2016 Minio, Inc.
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*
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* Licensed under the Apache License, Version 2.0 (the "License");
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* you may not use this file except in compliance with the License.
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* You may obtain a copy of the License at
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*
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* http://www.apache.org/licenses/LICENSE-2.0
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*
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* Unless required by applicable law or agreed to in writing, software
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* distributed under the License is distributed on an "AS IS" BASIS,
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* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
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* See the License for the specific language governing permissions and
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* limitations under the License.
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*/
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package dsync
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import (
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"errors"
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"math"
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)
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// Dsync represents dsync client object which is initialized with
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// authenticated clients, used to initiate lock REST calls.
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type Dsync struct {
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// Number of nodes participating in the distributed locking.
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dNodeCount int
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// List of rest client objects, one per lock server.
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restClnts []NetLocker
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// Simple majority based quorum, set to dNodeCount/2+1
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dquorum int
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// Simple quorum for read operations, set to dNodeCount/2
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dquorumReads int
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}
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// New - initializes a new dsync object with input restClnts.
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func New(restClnts []NetLocker) (*Dsync, error) {
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if len(restClnts) < 2 {
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return nil, errors.New("Dsync is not designed for less than 2 nodes")
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} else if len(restClnts) > 32 {
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return nil, errors.New("Dsync is not designed for more than 32 nodes")
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}
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ds := &Dsync{}
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ds.dNodeCount = len(restClnts)
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// With odd number of nodes, write and read quorum is basically the same
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ds.dquorum = int(ds.dNodeCount/2) + 1
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ds.dquorumReads = int(math.Ceil(float64(ds.dNodeCount) / 2.0))
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// Initialize node name and rest path for each NetLocker object.
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ds.restClnts = make([]NetLocker, ds.dNodeCount)
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copy(ds.restClnts, restClnts)
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return ds, nil
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}
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