40 lines
961 B
Go
40 lines
961 B
Go
package vm
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import (
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"bytes"
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"fmt"
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cbg "github.com/whyrusleeping/cbor-gen"
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"github.com/filecoin-project/lotus/chain/types"
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)
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const MaxEventSliceLength = 6_000_000
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// DecodeEvents decodes a CBOR list of CBOR-encoded events.
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func decodeEvents(input []byte) ([]types.Event, error) {
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r := bytes.NewReader(input)
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typ, length, err := cbg.NewCborReader(r).ReadHeader()
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if err != nil {
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return nil, fmt.Errorf("failed to read events: %w", err)
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}
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if length > MaxEventSliceLength {
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log.Errorf("extremely long event slice (len %d) returned, not decoding", length)
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return nil, nil
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}
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if typ != cbg.MajArray {
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return nil, fmt.Errorf("expected a CBOR list, was major type %d", typ)
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}
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events := make([]types.Event, 0, length)
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for i := 0; i < int(length); i++ {
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var evt types.Event
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if err := evt.UnmarshalCBOR(r); err != nil {
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return nil, fmt.Errorf("failed to parse event: %w", err)
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}
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events = append(events, evt)
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}
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return events, nil
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}
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