2047a74958
The union blockstore takes a list of blockstores. It returns the first satisfying read, and broadcasts writes to all stores. It can be used for operations that require reading from any two blockstores, for example WalkSnapshot.
109 lines
2.1 KiB
Go
109 lines
2.1 KiB
Go
package blockstore
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import (
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"context"
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blocks "github.com/ipfs/go-block-format"
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"github.com/ipfs/go-cid"
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)
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type unionBlockstore []Blockstore
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// Union returns an unioned blockstore.
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//
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// * Reads return from the first blockstore that has the value, querying in the
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// supplied order.
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// * Writes (puts and deltes) are broadcast to all stores.
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//
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func Union(stores ...Blockstore) Blockstore {
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return unionBlockstore(stores)
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}
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func (m unionBlockstore) Has(cid cid.Cid) (has bool, err error) {
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for _, bs := range m {
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if has, err = bs.Has(cid); has || err != nil {
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break
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}
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}
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return has, err
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}
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func (m unionBlockstore) Get(cid cid.Cid) (blk blocks.Block, err error) {
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for _, bs := range m {
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if blk, err = bs.Get(cid); err == nil || err != ErrNotFound {
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break
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}
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}
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return blk, err
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}
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func (m unionBlockstore) View(cid cid.Cid, callback func([]byte) error) (err error) {
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for _, bs := range m {
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if err = bs.View(cid, callback); err == nil || err != ErrNotFound {
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break
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}
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}
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return err
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}
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func (m unionBlockstore) GetSize(cid cid.Cid) (size int, err error) {
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for _, bs := range m {
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if size, err = bs.GetSize(cid); err == nil || err != ErrNotFound {
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break
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}
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}
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return size, err
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}
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func (m unionBlockstore) Put(block blocks.Block) (err error) {
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for _, bs := range m {
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if err = bs.Put(block); err != nil {
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break
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}
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}
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return err
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}
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func (m unionBlockstore) PutMany(blks []blocks.Block) (err error) {
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for _, bs := range m {
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if err = bs.PutMany(blks); err != nil {
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break
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}
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}
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return err
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}
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func (m unionBlockstore) DeleteBlock(cid cid.Cid) (err error) {
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for _, bs := range m {
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if err = bs.DeleteBlock(cid); err != nil {
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break
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}
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}
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return err
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}
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func (m unionBlockstore) AllKeysChan(ctx context.Context) (<-chan cid.Cid, error) {
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// this does not deduplicate; this interface needs to be revisited.
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outCh := make(chan cid.Cid)
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go func() {
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defer close(outCh)
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for _, bs := range m {
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ch, err := bs.AllKeysChan(ctx)
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if err != nil {
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return
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}
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for cid := range ch {
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outCh <- cid
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}
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}
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}()
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return outCh, nil
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}
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func (m unionBlockstore) HashOnRead(enabled bool) {
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panic("implement me")
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}
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