github.com/darrenli6/fabric-sdk-example@v0.0.0-20220109053535-94b13b56df8c/orderer/ledger/ledger.go (about) 1 /* 2 Copyright IBM Corp. 2016 All Rights Reserved. 3 4 Licensed under the Apache License, Version 2.0 (the "License"); 5 you may not use this file except in compliance with the License. 6 You may obtain a copy of the License at 7 8 http://www.apache.org/licenses/LICENSE-2.0 9 10 Unless required by applicable law or agreed to in writing, software 11 distributed under the License is distributed on an "AS IS" BASIS, 12 WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. 13 See the License for the specific language governing permissions and 14 limitations under the License. 15 */ 16 17 package ledger 18 19 import ( 20 cb "github.com/hyperledger/fabric/protos/common" 21 ab "github.com/hyperledger/fabric/protos/orderer" 22 ) 23 24 // Factory retrieves or creates new ledgers by chainID 25 type Factory interface { 26 // GetOrCreate gets an existing ledger (if it exists) 27 // or creates it if it does not 28 GetOrCreate(chainID string) (ReadWriter, error) 29 30 // ChainIDs returns the chain IDs the Factory is aware of 31 ChainIDs() []string 32 33 // Close releases all resources acquired by the factory 34 Close() 35 } 36 37 // Iterator is useful for a chain Reader to stream blocks as they are created 38 type Iterator interface { 39 // Next blocks until there is a new block available, or returns an error if 40 // the next block is no longer retrievable 41 Next() (*cb.Block, cb.Status) 42 // ReadyChan supplies a channel which will block until Next will not block 43 ReadyChan() <-chan struct{} 44 } 45 46 // Reader allows the caller to inspect the ledger 47 type Reader interface { 48 // Iterator returns an Iterator, as specified by a cb.SeekInfo message, and 49 // its starting block number 50 Iterator(startType *ab.SeekPosition) (Iterator, uint64) 51 // Height returns the number of blocks on the ledger 52 Height() uint64 53 } 54 55 // Writer allows the caller to modify the ledger 56 type Writer interface { 57 // Append a new block to the ledger 58 Append(block *cb.Block) error 59 } 60 61 // ReadWriter encapsulates the read/write functions of the ledger 62 type ReadWriter interface { 63 Reader 64 Writer 65 }