blockservice: add WithProvider option

This allows to recreate the behavior of advertising added blocks the bitswap server used to do.

CHANGELOG.md

@@ -19,6 +19,7 @@ The following emojis are used to highlight certain changes:
 - `blockservice` now has `ContextWithSession` and `EmbedSessionInContext` functions, which allows to embed a session in a context. Future calls to `BlockGetter.GetBlock`, `BlockGetter.GetBlocks` and `NewSession` will use the session in the context.
 - `blockservice.NewWritethrough` deprecated function has been removed, instead you can do `blockservice.New(..., ..., WriteThrough())` like previously.
 - `blockservice` now has `WithContentBlocker` option which allows to filter Add and Get requests by CID.
+- `blockservice` now have a `WithProvider` option, this allows to recreate the behavior of advertising added blocks the bitswap server used to do.
 
 ### Changed
 

blockservice/blockservice.go

@@ -12,6 +12,7 @@ import (
 
 	"github.com/ipfs/boxo/blockstore"
 	"github.com/ipfs/boxo/exchange"
+	"github.com/ipfs/boxo/provider"
 	"github.com/ipfs/boxo/verifcid"
 	blocks "github.com/ipfs/go-block-format"
 	"github.com/ipfs/go-cid"
@@ -50,6 +51,7 @@ type BlockService struct {
 	blocker    Blocker
 	blockstore blockstore.Blockstore
 	exchange   exchange.Interface
+	provider   provider.Provider
 	// If checkFirst is true then first check that a block doesn't
 	// already exist to avoid republishing the block on the exchange.
 	checkFirst bool
@@ -79,6 +81,13 @@ func WithContentBlocker(blocker Blocker) Option {
 	}
 }
 
+// WithProvider allows to advertise anything that is added through the blockservice.
+func WithProvider(prov provider.Provider) Option {
+	return func(bs *BlockService) {
+		bs.provider = prov
+	}
+}
+
 // New creates a BlockService with given datastore instance.
 func New(bs blockstore.Blockstore, exchange exchange.Interface, opts ...Option) *BlockService {
 	if exchange == nil {
@@ -153,6 +162,11 @@ func (s *BlockService) AddBlock(ctx context.Context, o blocks.Block) error {
 			logger.Errorf("NotifyNewBlocks: %s", err.Error())
 		}
 	}
+	if s.provider != nil {
+		if err := s.provider.Provide(o.Cid()); err != nil {
+			logger.Errorf("Provide: %s", err.Error())
+		}
+	}
 
 	return nil
 }
@@ -206,6 +220,14 @@ func (s *BlockService) AddBlocks(ctx context.Context, bs []blocks.Block) error {
 			logger.Errorf("NotifyNewBlocks: %s", err.Error())
 		}
 	}
+	if s.provider != nil {
+		for _, o := range toput {
+			if err := s.provider.Provide(o.Cid()); err != nil {
+				logger.Errorf("Provide: %s", err.Error())
+			}
+		}
+	}
+
 	return nil
 }
 
@@ -271,6 +293,12 @@ func (s *BlockService) getBlock(ctx context.Context, c cid.Cid, fetchFactory fun
 			return nil, err
 		}
 	}
+	if s.provider != nil {
+		err = s.provider.Provide(blk.Cid())
+		if err != nil {
+			return nil, err
+		}
+	}
 	logger.Debugf("BlockService.BlockFetched %s", c)
 	return blk, nil
 }
@@ -388,6 +416,14 @@ func (s *BlockService) getBlocks(ctx context.Context, ks []cid.Cid, fetchFactory
 				cache[0] = nil // early gc
 			}
 
+			if s.provider != nil {
+				err = s.provider.Provide(b.Cid())
+				if err != nil {
+					logger.Errorf("could not tell the provider about new blocks: %s", err)
+					return
+				}
+			}
+
 			select {
 			case out <- b:
 			case <-ctx.Done():

blockservice/blockservice_test.go

@@ -423,3 +423,31 @@ func TestBlocker(t *testing.T) {
 	}
 	a.True(gotAllowed, "did not got allowed block")
 }
+
+type mockProvider []cid.Cid
+
+func (p *mockProvider) Provide(c cid.Cid) error {
+	*p = append(*p, c)
+	return nil
+}
+
+func TestProviding(t *testing.T) {
+	t.Parallel()
+	a := assert.New(t)
+
+	bgen := butil.NewBlockGenerator()
+	blocks := bgen.Blocks(3)
+
+	prov := mockProvider{}
+	blockservice := New(blockstore.NewBlockstore(dssync.MutexWrap(ds.NewMapDatastore())), nil, WithProvider(&prov))
+	var added []cid.Cid
+
+	a.NoError(blockservice.AddBlock(context.Background(), blocks[0]))
+	added = append(added, blocks[0].Cid())
+
+	a.NoError(blockservice.AddBlocks(context.Background(), blocks[1:]))
+	added = append(added, blocks[1].Cid())
+	added = append(added, blocks[2].Cid())
+
+	a.ElementsMatch(added, []cid.Cid(prov))
+}

examples/go.mod

@@ -60,6 +60,7 @@ require (
 	github.com/huin/goupnp v1.3.0 // indirect
 	github.com/ipfs/bbloom v0.0.4 // indirect
 	github.com/ipfs/go-bitfield v1.1.0 // indirect
+	github.com/ipfs/go-cidutil v0.1.0 // indirect
 	github.com/ipfs/go-ipfs-delay v0.0.1 // indirect
 	github.com/ipfs/go-ipfs-pq v0.0.3 // indirect
 	github.com/ipfs/go-ipfs-redirects-file v0.1.1 // indirect

examples/go.sum

@@ -167,6 +167,8 @@ github.com/ipfs/go-blockservice v0.5.0 h1:B2mwhhhVQl2ntW2EIpaWPwSCxSuqr5fFA93Ms4
 github.com/ipfs/go-cid v0.0.6/go.mod h1:6Ux9z5e+HpkQdckYoX1PG/6xqKspzlEIR5SDmgqgC/I=
 github.com/ipfs/go-cid v0.4.1 h1:A/T3qGvxi4kpKWWcPC/PgbvDA2bjVLO7n4UeVwnbs/s=
 github.com/ipfs/go-cid v0.4.1/go.mod h1:uQHwDeX4c6CtyrFwdqyhpNcxVewur1M7l7fNU7LKwZk=
+github.com/ipfs/go-cidutil v0.1.0 h1:RW5hO7Vcf16dplUU60Hs0AKDkQAVPVplr7lk97CFL+Q=
+github.com/ipfs/go-cidutil v0.1.0/go.mod h1:e7OEVBMIv9JaOxt9zaGEmAoSlXW9jdFZ5lP/0PwcfpA=
 github.com/ipfs/go-datastore v0.6.0 h1:JKyz+Gvz1QEZw0LsX1IBn+JFCJQH4SJVFtM4uWU0Myk=
 github.com/ipfs/go-datastore v0.6.0/go.mod h1:rt5M3nNbSO/8q1t4LNkLyUwRs8HupMeN/8O4Vn9YAT8=
 github.com/ipfs/go-detect-race v0.0.1 h1:qX/xay2W3E4Q1U7d9lNs1sU9nvguX0a7319XbyQ6cOk=