github.com/leonlxy/hyperledger@v1.0.0-alpha.0.20170427033203-34922035d248/core/ledger/ledger_interface.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  	commonledger "github.com/hyperledger/fabric/common/ledger"
    21  	"github.com/hyperledger/fabric/protos/common"
    22  	"github.com/hyperledger/fabric/protos/peer"
    23  )
    24  
    25  // PeerLedgerProvider provides handle to ledger instances
    26  type PeerLedgerProvider interface {
    27  	// Create creates a new ledger with the given genesis block.
    28  	// This function guarentees that the creation of ledger and committing the genesis block would an atomic action
    29  	// The chain id retrieved from the genesis block is treated as a ledger id
    30  	Create(genesisBlock *common.Block) (PeerLedger, error)
    31  	// Open opens an already created ledger
    32  	Open(ledgerID string) (PeerLedger, error)
    33  	// Exists tells whether the ledger with given id exists
    34  	Exists(ledgerID string) (bool, error)
    35  	// List lists the ids of the existing ledgers
    36  	List() ([]string, error)
    37  	// Close closes the PeerLedgerProvider
    38  	Close()
    39  }
    40  
    41  // PeerLedger differs from the OrdererLedger in that PeerLedger locally maintain a bitmask
    42  // that tells apart valid transactions from invalid ones
    43  type PeerLedger interface {
    44  	commonledger.Ledger
    45  	// GetTransactionByID retrieves a transaction by id
    46  	GetTransactionByID(txID string) (*peer.ProcessedTransaction, error)
    47  	// GetBlockByHash returns a block given it's hash
    48  	GetBlockByHash(blockHash []byte) (*common.Block, error)
    49  	// GetBlockByTxID returns a block which contains a transaction
    50  	GetBlockByTxID(txID string) (*common.Block, error)
    51  	// NewTxSimulator gives handle to a transaction simulator.
    52  	// A client can obtain more than one 'TxSimulator's for parallel execution.
    53  	// Any snapshoting/synchronization should be performed at the implementation level if required
    54  
    55  	// GetTxValidationCodeByTxID returns reason code of transaction validation
    56  	GetTxValidationCodeByTxID(txID string) (peer.TxValidationCode, error)
    57  	NewTxSimulator() (TxSimulator, error)
    58  	// NewQueryExecutor gives handle to a query executor.
    59  	// A client can obtain more than one 'QueryExecutor's for parallel execution.
    60  	// Any synchronization should be performed at the implementation level if required
    61  	NewQueryExecutor() (QueryExecutor, error)
    62  	// NewHistoryQueryExecutor gives handle to a history query executor.
    63  	// A client can obtain more than one 'HistoryQueryExecutor's for parallel execution.
    64  	// Any synchronization should be performed at the implementation level if required
    65  	NewHistoryQueryExecutor() (HistoryQueryExecutor, error)
    66  	//Prune prunes the blocks/transactions that satisfy the given policy
    67  	Prune(policy commonledger.PrunePolicy) error
    68  }
    69  
    70  // ValidatedLedger represents the 'final ledger' after filtering out invalid transactions from PeerLedger.
    71  // Post-v1
    72  type ValidatedLedger interface {
    73  	commonledger.Ledger
    74  }
    75  
    76  // QueryExecutor executes the queries
    77  // Get* methods are for supporting KV-based data model. ExecuteQuery method is for supporting a rich datamodel and query support
    78  //
    79  // ExecuteQuery method in the case of a rich data model is expected to support queries on
    80  // latest state, historical state and on the intersection of state and transactions
    81  type QueryExecutor interface {
    82  	// GetState gets the value for given namespace and key. For a chaincode, the namespace corresponds to the chaincodeId
    83  	GetState(namespace string, key string) ([]byte, error)
    84  	// GetStateMultipleKeys gets the values for multiple keys in a single call
    85  	GetStateMultipleKeys(namespace string, keys []string) ([][]byte, error)
    86  	// GetStateRangeScanIterator returns an iterator that contains all the key-values between given key ranges.
    87  	// startKey is included in the results and endKey is excluded. An empty startKey refers to the first available key
    88  	// and an empty endKey refers to the last available key. For scanning all the keys, both the startKey and the endKey
    89  	// can be supplied as empty strings. However, a full scan shuold be used judiciously for performance reasons.
    90  	// The returned ResultsIterator contains results of type *KV which is defined in protos/ledger/queryresult.
    91  	GetStateRangeScanIterator(namespace string, startKey string, endKey string) (commonledger.ResultsIterator, error)
    92  	// ExecuteQuery executes the given query and returns an iterator that contains results of type specific to the underlying data store.
    93  	// Only used for state databases that support query
    94  	// For a chaincode, the namespace corresponds to the chaincodeId
    95  	// The returned ResultsIterator contains results of type *KV which is defined in protos/ledger/queryresult.
    96  	ExecuteQuery(namespace, query string) (commonledger.ResultsIterator, error)
    97  	// Done releases resources occupied by the QueryExecutor
    98  	Done()
    99  }
   100  
   101  // HistoryQueryExecutor executes the history queries
   102  type HistoryQueryExecutor interface {
   103  	// GetHistoryForKey retrieves the history of values for a key.
   104  	// The returned ResultsIterator contains results of type *KeyModification which is defined in protos/ledger/queryresult.
   105  	GetHistoryForKey(namespace string, key string) (commonledger.ResultsIterator, error)
   106  }
   107  
   108  // TxSimulator simulates a transaction on a consistent snapshot of the 'as recent state as possible'
   109  // Set* methods are for supporting KV-based data model. ExecuteUpdate method is for supporting a rich datamodel and query support
   110  type TxSimulator interface {
   111  	QueryExecutor
   112  	// SetState sets the given value for the given namespace and key. For a chaincode, the namespace corresponds to the chaincodeId
   113  	SetState(namespace string, key string, value []byte) error
   114  	// DeleteState deletes the given namespace and key
   115  	DeleteState(namespace string, key string) error
   116  	// SetMultipleKeys sets the values for multiple keys in a single call
   117  	SetStateMultipleKeys(namespace string, kvs map[string][]byte) error
   118  	// ExecuteUpdate for supporting rich data model (see comments on QueryExecutor above)
   119  	ExecuteUpdate(query string) error
   120  	// GetTxSimulationResults encapsulates the results of the transaction simulation.
   121  	// This should contain enough detail for
   122  	// - The update in the state that would be caused if the transaction is to be committed
   123  	// - The environment in which the transaction is executed so as to be able to decide the validity of the enviroment
   124  	//   (at a later time on a different peer) during committing the transactions
   125  	// Different ledger implementation (or configurations of a single implementation) may want to represent the above two pieces
   126  	// of information in different way in order to support different data-models or optimize the information representations.
   127  	GetTxSimulationResults() ([]byte, error)
   128  }