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