From b628958cf68790ddcfb8ddd074c505a159ca4a91 Mon Sep 17 00:00:00 2001
From: Aayush Rajasekaran <arajasek94@gmail.com>
Date: Tue, 11 Jan 2022 17:44:45 -0500
Subject: [PATCH] implement stubs

---
 blockstore/autobatch.go            | 119 +++++++++++++++++++----------
 chain/consensus/filcns/upgrades.go |   9 +--
 2 files changed, 81 insertions(+), 47 deletions(-)

diff --git a/blockstore/autobatch.go b/blockstore/autobatch.go
index 5d78e92a1..ed52f39cd 100644
--- a/blockstore/autobatch.go
+++ b/blockstore/autobatch.go
@@ -4,6 +4,8 @@ import (
 	"context"
 	"sync"
 
+	"golang.org/x/xerrors"
+
 	block "github.com/ipfs/go-block-format"
 	"github.com/ipfs/go-cid"
 )
@@ -22,38 +24,6 @@ type AutobatchBlockstore struct {
 	bufferSize     int
 }
 
-func (bs *AutobatchBlockstore) DeleteBlock(context.Context, cid.Cid) error {
-	panic("implement me")
-}
-
-func (bs *AutobatchBlockstore) Has(ctx context.Context, c cid.Cid) (bool, error) {
-	panic("implement me")
-}
-
-func (bs *AutobatchBlockstore) GetSize(context.Context, cid.Cid) (int, error) {
-	panic("implement me")
-}
-
-func (bs *AutobatchBlockstore) PutMany(context.Context, []block.Block) error {
-	panic("implement me")
-}
-
-func (bs *AutobatchBlockstore) AllKeysChan(ctx context.Context) (<-chan cid.Cid, error) {
-	panic("implement me")
-}
-
-func (bs *AutobatchBlockstore) HashOnRead(enabled bool) {
-	panic("implement me")
-}
-
-func (bs *AutobatchBlockstore) View(ctx context.Context, cid cid.Cid, callback func([]byte) error) error {
-	panic("implement me")
-}
-
-func (bs *AutobatchBlockstore) DeleteMany(ctx context.Context, cids []cid.Cid) error {
-	panic("implement me")
-}
-
 func NewAutobatch(ctx context.Context, backingBs Blockstore, bufferCapacity int) *AutobatchBlockstore {
 	bs := &AutobatchBlockstore{
 		backingBs:      backingBs,
@@ -64,12 +34,6 @@ func NewAutobatch(ctx context.Context, backingBs Blockstore, bufferCapacity int)
 	return bs
 }
 
-// May NOT `Get` blocks that have been `Put` into this store
-// Only guaranteed to fetch those that were already in the backingBs at creation of this store and those at the most recent `Flush`
-func (bs *AutobatchBlockstore) Get(ctx context.Context, c cid.Cid) (block.Block, error) {
-	return bs.backingBs.Get(ctx, c)
-}
-
 func (bs *AutobatchBlockstore) Put(ctx context.Context, blk block.Block) error {
 	bs.bufferedBlksLk.Lock()
 	_, ok := bs.addedCids[blk.Cid()]
@@ -90,9 +54,84 @@ func (bs *AutobatchBlockstore) Flush(ctx context.Context) {
 	bs.flushLk.Lock()
 	defer bs.flushLk.Unlock()
 	bs.bufferedBlksLk.Lock()
+	// We do NOT clear addedCids here, because its purpose is to expedite Puts
 	toFlush := bs.bufferedBlks
 	bs.bufferedBlks = []block.Block{}
 	bs.bufferedBlksLk.Unlock()
-	// error?????
-	bs.backingBs.PutMany(ctx, toFlush)
+	err := bs.backingBs.PutMany(ctx, toFlush)
+	autolog.Errorf("FLUSH ERRORED, maybe async: %w", err)
+}
+
+// May be very slow if the cid queried wasn't in the backingBs at the time of creation of this AutobatchBlockstore
+func (bs *AutobatchBlockstore) Get(ctx context.Context, c cid.Cid) (block.Block, error) {
+	blk, err := bs.backingBs.Get(ctx, c)
+	if err == nil {
+		return blk, nil
+	}
+
+	if err != ErrNotFound {
+		return blk, err
+	}
+
+	bs.Flush(ctx)
+	return bs.backingBs.Get(ctx, c)
+}
+
+func (bs *AutobatchBlockstore) DeleteBlock(context.Context, cid.Cid) error {
+	// if we wanted to support this, we would have to:
+	// - flush
+	// - delete from the backingBs (if present)
+	// - remove from addedCids (if present)
+	// - if present in addedCids, also walk bufferedBlks and remove if present
+	return xerrors.New("deletion is unsupported")
+}
+
+func (bs *AutobatchBlockstore) DeleteMany(ctx context.Context, cids []cid.Cid) error {
+	// see note in DeleteBlock()
+	return xerrors.New("deletion is unsupported")
+}
+
+func (bs *AutobatchBlockstore) Has(ctx context.Context, c cid.Cid) (bool, error) {
+	_, err := bs.Get(ctx, c)
+	if err == nil {
+		return true, nil
+	}
+	if err == ErrNotFound {
+		return false, nil
+	}
+
+	return false, err
+}
+
+func (bs *AutobatchBlockstore) GetSize(ctx context.Context, c cid.Cid) (int, error) {
+	blk, err := bs.Get(ctx, c)
+	if err != nil {
+		return 0, err
+	}
+
+	return len(blk.RawData()), nil
+}
+
+func (bs *AutobatchBlockstore) PutMany(ctx context.Context, blks []block.Block) error {
+	for _, blk := range blks {
+		if err := bs.Put(ctx, blk); err != nil {
+			return err
+		}
+	}
+
+	return nil
+}
+
+func (bs *AutobatchBlockstore) AllKeysChan(ctx context.Context) (<-chan cid.Cid, error) {
+	bs.Flush(ctx)
+	return bs.backingBs.AllKeysChan(ctx)
+}
+
+func (bs *AutobatchBlockstore) HashOnRead(enabled bool) {
+	bs.backingBs.HashOnRead(enabled)
+}
+
+func (bs *AutobatchBlockstore) View(ctx context.Context, cid cid.Cid, callback func([]byte) error) error {
+	bs.Flush(ctx)
+	return bs.backingBs.View(ctx, cid, callback)
 }
diff --git a/chain/consensus/filcns/upgrades.go b/chain/consensus/filcns/upgrades.go
index 548f59aac..c7b407a6d 100644
--- a/chain/consensus/filcns/upgrades.go
+++ b/chain/consensus/filcns/upgrades.go
@@ -1264,11 +1264,7 @@ func upgradeActorsV7Common(
 	root cid.Cid, epoch abi.ChainEpoch, ts *types.TipSet,
 	config nv15.Config,
 ) (cid.Cid, error) {
-
-	ctxWithCancel, cancel := context.WithCancel(ctx)
-	defer cancel()
-
-	writeStore := blockstore.NewAutobatch(ctxWithCancel, sm.ChainStore().StateBlockstore(), units.GiB)
+	writeStore := blockstore.NewAutobatch(ctx, sm.ChainStore().StateBlockstore(), units.GiB)
 	// TODO: pretty sure we'd achieve nothing by doing this, confirm in review
 	//buf := blockstore.NewTieredBstore(sm.ChainStore().StateBlockstore(), writeStore)
 	store := store.ActorStore(ctx, writeStore)
@@ -1301,8 +1297,7 @@ func upgradeActorsV7Common(
 		return cid.Undef, xerrors.Errorf("failed to persist new state root: %w", err)
 	}
 
-	// Persist the new tree.
-
+	// Persist the new tree. Blocks until the entire writeStore is in the state blockstore.
 	writeStore.Flush(ctx)
 
 	return newRoot, nil