106 lines
2.4 KiB
Go
106 lines
2.4 KiB
Go
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package raft
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import (
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"context"
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"errors"
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"go.opencensus.io/tag"
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"go.opencensus.io/trace"
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"github.com/ipfs-cluster/ipfs-cluster/api"
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"github.com/ipfs-cluster/ipfs-cluster/state"
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consensus "github.com/libp2p/go-libp2p-consensus"
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)
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// Type of consensus operation
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const (
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LogOpPin = iota + 1
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LogOpUnpin
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)
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// LogOpType expresses the type of a consensus Operation
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type LogOpType int
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// LogOp represents an operation for the OpLogConsensus system.
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// It implements the consensus.Op interface and it is used by the
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// Consensus component.
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type LogOp struct {
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SpanCtx trace.SpanContext `codec:"s,omitempty"`
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TagCtx []byte `codec:"t,omitempty"`
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Cid api.Pin `codec:"c,omitempty"`
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Type LogOpType `codec:"p,omitempty"`
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consensus *Consensus `codec:"-"`
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tracing bool `codec:"-"`
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}
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// ApplyTo applies the operation to the State
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func (op *LogOp) ApplyTo(cstate consensus.State) (consensus.State, error) {
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var err error
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ctx := context.Background()
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if op.tracing {
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tagmap, err := tag.Decode(op.TagCtx)
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if err != nil {
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logger.Error(err)
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}
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ctx = tag.NewContext(ctx, tagmap)
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var span *trace.Span
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ctx, span = trace.StartSpanWithRemoteParent(ctx, "consensus/raft/logop/ApplyTo", op.SpanCtx)
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defer span.End()
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}
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state, ok := cstate.(state.State)
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if !ok {
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// Should never be here
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panic("received unexpected state type")
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}
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pin := op.Cid
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switch op.Type {
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case LogOpPin:
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err = state.Add(ctx, pin)
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if err != nil {
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logger.Error(err)
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goto ROLLBACK
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}
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// Async, we let the PinTracker take care of any problems
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op.consensus.rpcClient.GoContext(
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ctx,
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"",
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"PinTracker",
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"Track",
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pin,
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&struct{}{},
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nil,
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)
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case LogOpUnpin:
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err = state.Rm(ctx, pin.Cid)
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if err != nil {
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logger.Error(err)
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goto ROLLBACK
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}
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// Async, we let the PinTracker take care of any problems
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op.consensus.rpcClient.GoContext(
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ctx,
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"",
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"PinTracker",
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"Untrack",
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pin,
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&struct{}{},
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nil,
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)
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default:
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logger.Error("unknown LogOp type. Ignoring")
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}
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return state, nil
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ROLLBACK:
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// We failed to apply the operation to the state
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// and therefore we need to request a rollback to the
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// cluster to the previous state. This operation can only be performed
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// by the cluster leader.
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logger.Error("Rollbacks are not implemented")
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return nil, errors.New("a rollback may be necessary. Reason: " + err.Error())
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}
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