[FAB-2204] File LedgerType w/ fsblkstorage

The orderer "file" LedgerType re-introduced with the
leveldb based fsblkstorage backing store.

* I removed the previously provided OrdererLedger and
  OrdererLedgerProvider interfaces, instead choosing
  to implement the ordererledger.Factory interface
  and its corresponding ledger interfaces.
* A Close() method was added to the Factory interface.

Change-Id: I43007f3c570633896ef29de32fcd32c3301efcff
Signed-off-by: Luis Sanchez <sanchezl@us.ibm.com>

orderer/ledger/blackbox_test.go

@@ -73,6 +73,7 @@ func testInitialization(lf ledgerTestFactory, t *testing.T) {
 	if block == nil {
 		t.Fatalf("Error retrieving genesis block")
 	}
+
 }
 
 func TestReinitialization(t *testing.T) {
@@ -84,12 +85,13 @@ func testReinitialization(lf ledgerTestFactory, t *testing.T) {
 		t.Log("Skipping test as persistence is not available for this ledger type")
 		return
 	}
-	_, oli := lf.New()
+	olf, oli := lf.New()
 	aBlock := CreateNextBlock(oli, []*cb.Envelope{&cb.Envelope{Payload: []byte("My Data")}})
 	err := oli.Append(aBlock)
 	if err != nil {
 		t.Fatalf("Error appending block: %s", err)
 	}
+	olf.Close()
 
 	_, li := lf.New()
 	if li.Height() != 2 {

orderer/ledger/file/factory.go

@@ -0,0 +1,78 @@
+/*
+Copyright IBM Corp. 2017 All Rights Reserved.
+
+Licensed under the Apache License, Version 2.0 (the "License");
+you may not use this file except in compliance with the License.
+You may obtain a copy of the License at
+
+                 http://www.apache.org/licenses/LICENSE-2.0
+
+Unless required by applicable law or agreed to in writing, software
+distributed under the License is distributed on an "AS IS" BASIS,
+WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+See the License for the specific language governing permissions and
+limitations under the License.
+*/
+
+package fileledger
+
+import (
+	"sync"
+
+	"github.com/hyperledger/fabric/common/ledger/blkstorage"
+	"github.com/hyperledger/fabric/common/ledger/blkstorage/fsblkstorage"
+	ordererledger "github.com/hyperledger/fabric/orderer/ledger"
+)
+
+type fileLedgerFactory struct {
+	blkstorageProvider blkstorage.BlockStoreProvider
+	ledgers            map[string]ordererledger.ReadWriter
+	mutex              sync.Mutex
+}
+
+// GetOrCreate gets an existing ledger (if it exists) or creates it if it does not
+func (lf *fileLedgerFactory) GetOrCreate(chainID string) (ordererledger.ReadWriter, error) {
+	lf.mutex.Lock()
+	defer lf.mutex.Unlock()
+
+	key := chainID
+	// check cache
+	ledger, ok := lf.ledgers[key]
+	if ok {
+		return ledger, nil
+	}
+	// open fresh
+	blockStore, err := lf.blkstorageProvider.OpenBlockStore(key)
+	if err != nil {
+		return nil, err
+	}
+	ledger = &fileLedger{blockStore: blockStore, signal: make(chan struct{})}
+	lf.ledgers[key] = ledger
+	return ledger, nil
+}
+
+// ChainIDs returns the chain IDs the Factory is aware of
+func (lf *fileLedgerFactory) ChainIDs() []string {
+	chainIDs, err := lf.blkstorageProvider.List()
+	if err != nil {
+		panic(err)
+	}
+	return chainIDs
+}
+
+// Close closes the file ledgers served by this factory
+func (lf *fileLedgerFactory) Close() {
+	lf.blkstorageProvider.Close()
+}
+
+// New creates a new ledger factory
+func New(directory string) ordererledger.Factory {
+	return &fileLedgerFactory{
+		blkstorageProvider: fsblkstorage.NewProvider(
+			fsblkstorage.NewConf(directory, -1),
+			&blkstorage.IndexConfig{
+				AttrsToIndex: []blkstorage.IndexableAttr{blkstorage.IndexableAttrBlockNum}},
+		),
+		ledgers: make(map[string]ordererledger.ReadWriter),
+	}
+}

orderer/ledger/file/fileledger.go

@@ -0,0 +1,111 @@
+/*
+Copyright IBM Corp. 2016 All Rights Reserved.
+
+Licensed under the Apache License, Version 2.0 (the "License");
+you may not use this file except in compliance with the License.
+You may obtain a copy of the License at
+
+                 http://www.apache.org/licenses/LICENSE-2.0
+
+Unless required by applicable law or agreed to in writing, software
+distributed under the License is distributed on an "AS IS" BASIS,
+WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+See the License for the specific language governing permissions and
+limitations under the License.
+*/
+
+package fileledger
+
+import (
+	"github.com/hyperledger/fabric/common/ledger/blkstorage"
+	ordererledger "github.com/hyperledger/fabric/orderer/ledger"
+	cb "github.com/hyperledger/fabric/protos/common"
+	ab "github.com/hyperledger/fabric/protos/orderer"
+	"github.com/op/go-logging"
+)
+
+var logger = logging.MustGetLogger("ordererledger/fileledger")
+var closedChan chan struct{}
+
+func init() {
+	closedChan = make(chan struct{})
+	close(closedChan)
+}
+
+type fileLedger struct {
+	blockStore blkstorage.BlockStore
+	signal     chan struct{}
+}
+
+type fileLedgerIterator struct {
+	ledger      *fileLedger
+	blockNumber uint64
+}
+
+// Next blocks until there is a new block available, or returns an error if the
+// next block is no longer retrievable
+func (i *fileLedgerIterator) Next() (*cb.Block, cb.Status) {
+	for {
+		if i.blockNumber < i.ledger.Height() {
+			block, err := i.ledger.blockStore.RetrieveBlockByNumber(i.blockNumber)
+			if err != nil {
+				return nil, cb.Status_SERVICE_UNAVAILABLE
+			}
+			i.blockNumber++
+			return block, cb.Status_SUCCESS
+		}
+		<-i.ledger.signal
+	}
+}
+
+// ReadyChan supplies a channel which will block until Next will not block
+func (i *fileLedgerIterator) ReadyChan() <-chan struct{} {
+	signal := i.ledger.signal
+	if i.blockNumber > i.ledger.Height()-1 {
+		return signal
+	}
+	return closedChan
+}
+
+// Iterator returns an Iterator, as specified by a cb.SeekInfo message, and its
+// starting block number
+func (fl *fileLedger) Iterator(startPosition *ab.SeekPosition) (ordererledger.Iterator, uint64) {
+	switch start := startPosition.Type.(type) {
+	case *ab.SeekPosition_Oldest:
+		return &fileLedgerIterator{ledger: fl, blockNumber: 0}, 0
+	case *ab.SeekPosition_Newest:
+		info, err := fl.blockStore.GetBlockchainInfo()
+		if err != nil {
+			panic(err)
+		}
+		newestBlockNumber := info.Height - 1
+		return &fileLedgerIterator{ledger: fl, blockNumber: newestBlockNumber}, newestBlockNumber
+	case *ab.SeekPosition_Specified:
+		height := fl.Height()
+		if start.Specified.Number > height {
+			return &ordererledger.NotFoundErrorIterator{}, 0
+		}
+		return &fileLedgerIterator{ledger: fl, blockNumber: start.Specified.Number}, start.Specified.Number
+	}
+	// This line should be unreachable, but the compiler requires it
+	return &ordererledger.NotFoundErrorIterator{}, 0
+}
+
+// Height returns the number of blocks on the ledger
+func (fl *fileLedger) Height() uint64 {
+	info, err := fl.blockStore.GetBlockchainInfo()
+	if err != nil {
+		panic(err)
+	}
+	return info.Height
+}
+
+// Append a new block to the ledger
+func (fl *fileLedger) Append(block *cb.Block) error {
+	err := fl.blockStore.AddBlock(block)
+	if err == nil {
+		close(fl.signal)
+		fl.signal = make(chan struct{})
+	}
+	return err
+}