fetcher.go

package dasmon

import (
	"context"
	"io"
)

type Fetcher interface {
	io.Closer

	// FetchCommitments retrieves the BlockCommitmentInfos for a range of slots.
	FetchCommitments(context.Context, Range[uint64]) ([]*BlockCommitmentInfo, error)

	// MaxSlotsPerFetch specifies the maximum number of slots that can be fetched in a single call.
	MaxSlotsPerFetch() uint64
}

var _ Fetcher = ChainedFetcher{}

type ChainedFetcher []Fetcher

func (cf ChainedFetcher) Close() error {
	for _, f := range cf {
		f.Close()
	}
	return nil
}

func (cf ChainedFetcher) MaxSlotsPerFetch() uint64 {
	return cf[0].MaxSlotsPerFetch()
}

func (cf ChainedFetcher) FetchCommitments(ctx context.Context, r Range[uint64]) ([]*BlockCommitmentInfo, error) {
	var finalErr error
	for _, f := range cf {
		infos, err := f.FetchCommitments(ctx, r)
		if err == nil {
			return infos, nil
		}
		if finalErr == nil {
			finalErr = err
		}
	}
	return nil, finalErr
}