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package derive
import (
"context"
"io"
"github.com/ethereum/go-ethereum/log"
"github.com/ethereum-optimism/optimism/op-node/eth"
)
var _ NextFrameProvider = &FrameQueue{}
type NextDataProvider interface {
NextData(context.Context) ([]byte, error)
Origin() eth.L1BlockRef
}
type FrameQueue struct {
log log.Logger
frames []Frame
prev NextDataProvider
}
func NewFrameQueue(log log.Logger, prev NextDataProvider) *FrameQueue {
return &FrameQueue{
log: log,
prev: prev,
}
}
func (fq *FrameQueue) Origin() eth.L1BlockRef {
return fq.prev.Origin()
}
func (fq *FrameQueue) NextFrame(ctx context.Context) (Frame, error) {
// Find more frames if we need to
if len(fq.frames) == 0 {
if data, err := fq.prev.NextData(ctx); err != nil {
return Frame{}, err
} else {
if new, err := ParseFrames(data); err == nil {
fq.frames = append(fq.frames, new...)
} else {
fq.log.Warn("Failed to parse frames", "origin", fq.prev.Origin(), "err", err)
}
}
}
// If we did not add more frames but still have more data, retry this function.
if len(fq.frames) == 0 {
return Frame{}, NotEnoughData
}
ret := fq.frames[0]
fq.frames = fq.frames[1:]
return ret, nil
}
func (fq *FrameQueue) Reset(_ context.Context, _ eth.L1BlockRef, _ eth.SystemConfig) error {
fq.frames = fq.frames[:0]
return io.EOF
}