github.com/lzy4123/fabric@v2.1.1+incompatible/core/handlers/validation/api/state/state.go (about)

     1  /*
     2  Copyright IBM Corp. All Rights Reserved.
     3  
     4  SPDX-License-Identifier: Apache-2.0
     5  */
     6  
     7  package validation
     8  
     9  import (
    10  	validation "github.com/hyperledger/fabric/core/handlers/validation/api"
    11  )
    12  
    13  // State defines interaction with the world state
    14  type State interface {
    15  	// GetStateMultipleKeys gets the values for multiple keys in a single call
    16  	GetStateMultipleKeys(namespace string, keys []string) ([][]byte, error)
    17  
    18  	// GetStateRangeScanIterator returns an iterator that contains all the key-values between given key ranges.
    19  	// startKey is included in the results and endKey is excluded. An empty startKey refers to the first available key
    20  	// and an empty endKey refers to the last available key. For scanning all the keys, both the startKey and the endKey
    21  	// can be supplied as empty strings. However, a full scan should be used judiciously for performance reasons.
    22  	// The returned ResultsIterator contains results of type *KV which is defined in fabric-protos/ledger/queryresult.
    23  	GetStateRangeScanIterator(namespace string, startKey string, endKey string) (ResultsIterator, error)
    24  
    25  	// GetStateMetadata returns the metadata for given namespace and key
    26  	GetStateMetadata(namespace, key string) (map[string][]byte, error)
    27  
    28  	// GetPrivateDataMetadataByHash gets the metadata of a private data item identified by a tuple <namespace, collection, keyhash>
    29  	GetPrivateDataMetadataByHash(namespace, collection string, keyhash []byte) (map[string][]byte, error)
    30  
    31  	// Done releases resources occupied by the State
    32  	Done()
    33  }
    34  
    35  // StateFetcher retrieves an instance of a state
    36  type StateFetcher interface {
    37  	validation.Dependency
    38  
    39  	// FetchState fetches state
    40  	FetchState() (State, error)
    41  }
    42  
    43  // ResultsIterator - an iterator for query result set
    44  type ResultsIterator interface {
    45  	// Next returns the next item in the result set. The `QueryResult` is expected to be nil when
    46  	// the iterator gets exhausted
    47  	Next() (QueryResult, error)
    48  	// Close releases resources occupied by the iterator
    49  	Close()
    50  }
    51  
    52  // QueryResult - a general interface for supporting different types of query results. Actual types differ for different queries
    53  type QueryResult interface{}