statedb

Documentation

Index

• type BulkOptimizable
• type CompositeKey
• type FullScanIterator
• type IndexCapable
• type NamespaceProvider
• type QueryResult
• type QueryResultsIterator
• type ResultsIterator
• type UpdateBatch
  • func NewUpdateBatch() *UpdateBatch
  • func (batch *UpdateBatch) Delete(ns string, key string, version *version.Height)
  • func (batch *UpdateBatch) Exists(ns string, key string) bool
  • func (batch *UpdateBatch) Get(ns string, key string) *VersionedValue
  • func (batch *UpdateBatch) GetRangeScanIterator(ns string, startKey string, endKey string) QueryResultsIterator
  • func (batch *UpdateBatch) GetUpdatedNamespaces() []string
  • func (batch *UpdateBatch) GetUpdates(ns string) map[string]*VersionedValue
  • func (batch *UpdateBatch) Merge(toMerge *UpdateBatch)
  • func (batch *UpdateBatch) Put(ns string, key string, value []byte, version *version.Height)
  • func (batch *UpdateBatch) PutValAndMetadata(ns string, key string, value []byte, metadata []byte, version *version.Height)
  • func (batch *UpdateBatch) Update(ns string, key string, vv *VersionedValue)
• type VersionedDB
• type VersionedDBProvider
• type VersionedKV
• type VersionedValue
  • func (vv *VersionedValue) IsDelete() bool

Types

type BulkOptimizable

type BulkOptimizable interface {
	LoadCommittedVersions(keys []*CompositeKey) error
	GetCachedVersion(namespace, key string) (*version.Height, bool)
	ClearCachedVersions()
}

BulkOptimizable interface provides additional functions for databases capable of batch operations

type CompositeKey

type CompositeKey struct {
	Namespace string
	Key       string
}

CompositeKey encloses Namespace and Key components

type FullScanIterator

type FullScanIterator interface {
	// Next returns the key-values in the lexical order of <Namespace, key>
	// A particular statedb implementation is free to chose any deterministic bytes representation for the <version, value, metadata>
	Next() (*CompositeKey, []byte, error)
	// Close releases any resources held with the implementation
	Close()
}

FullScanIterator provides a mean to iterate over entire statedb. The intended use of this iterator is to generate the snapshot files for the statedb

type IndexCapable

type IndexCapable interface {
	GetDBType() string
	ProcessIndexesForChaincodeDeploy(namespace string, indexFilesData map[string][]byte) error
}

IndexCapable interface provides additional functions for databases capable of index operations

type NamespaceProvider

type NamespaceProvider interface {
	// PossibleNamespaces returns all possible namespaces for the statedb. Note that it is a superset
	// of the actual namespaces. Therefore, the caller should compare with the existing databases to
	// filter out the namespaces that have no matched databases.
	PossibleNamespaces(vdb VersionedDB) ([]string, error)
}

NamespaceProvider provides a mean for statedb to get all the possible namespaces for a channel. The intended use is for statecouchdb to retroactively build channel metadata when it is missing, e.g., when opening a statecouchdb from v2.0/2.1 version.

type QueryResult

type QueryResult interface{}

QueryResult - a general interface for supporting different types of query results. Actual types differ for different queries

type QueryResultsIterator

type QueryResultsIterator interface {
	ResultsIterator
	GetBookmarkAndClose() string
}

QueryResultsIterator adds GetBookmarkAndClose method

type ResultsIterator

type ResultsIterator interface {
	Next() (QueryResult, error)
	Close()
}

ResultsIterator iterates over query results

type UpdateBatch

type UpdateBatch struct {
	ContainsPostOrderWrites bool
	Updates                 map[string]*nsUpdates
}

UpdateBatch encloses the details of multiple `updates`

func NewUpdateBatch

func NewUpdateBatch() *UpdateBatch

NewUpdateBatch constructs an instance of a Batch

func (*UpdateBatch) Delete

func (batch *UpdateBatch) Delete(ns string, key string, version *version.Height)

Delete deletes a Key and associated value

func (*UpdateBatch) Exists

func (batch *UpdateBatch) Exists(ns string, key string) bool

Exists checks whether the given key exists in the batch

func (*UpdateBatch) Get

func (batch *UpdateBatch) Get(ns string, key string) *VersionedValue

Get returns the VersionedValue for the given namespace and key

func (*UpdateBatch) GetRangeScanIterator

func (batch *UpdateBatch) GetRangeScanIterator(ns string, startKey string, endKey string) QueryResultsIterator

GetRangeScanIterator returns an iterator that iterates over keys of a specific namespace in sorted order In other word this gives the same functionality over the contents in the `UpdateBatch` as `VersionedDB.GetStateRangeScanIterator()` method gives over the contents in the statedb This function can be used for querying the contents in the updateBatch before they are committed to the statedb. For instance, a validator implementation can used this to verify the validity of a range query of a transaction where the UpdateBatch represents the union of the modifications performed by the preceding valid transactions in the same block (Assuming Group commit approach where we commit all the updates caused by a block together).

func (*UpdateBatch) GetUpdatedNamespaces

func (batch *UpdateBatch) GetUpdatedNamespaces() []string

GetUpdatedNamespaces returns the names of the namespaces that are updated

func (*UpdateBatch) GetUpdates

func (batch *UpdateBatch) GetUpdates(ns string) map[string]*VersionedValue

GetUpdates returns all the updates for a namespace

func (*UpdateBatch) Merge

func (batch *UpdateBatch) Merge(toMerge *UpdateBatch)

Merge merges another updates batch with this updates batch

func (*UpdateBatch) Put

func (batch *UpdateBatch) Put(ns string, key string, value []byte, version *version.Height)

Put adds a key with value only. The metadata is assumed to be nil

func (*UpdateBatch) PutValAndMetadata

func (batch *UpdateBatch) PutValAndMetadata(ns string, key string, value []byte, metadata []byte, version *version.Height)

PutValAndMetadata adds a key with value and metadata TODO introducing a new function to limit the refactoring. Later in a separate CR, the 'Put' function above should be removed

func (*UpdateBatch) Update

func (batch *UpdateBatch) Update(ns string, key string, vv *VersionedValue)

Update updates the batch with a latest entry for a namespace and a key

type VersionedDB

type VersionedDB interface {
	// GetState gets the value for given namespace and key. For a chaincode, the namespace corresponds to the chaincodeId
	GetState(namespace string, key string) (*VersionedValue, error)
	// GetVersion gets the version for given namespace and key. For a chaincode, the namespace corresponds to the chaincodeId
	GetVersion(namespace string, key string) (*version.Height, error)
	// GetStateMultipleKeys gets the values for multiple keys in a single call
	GetStateMultipleKeys(namespace string, keys []string) ([]*VersionedValue, error)
	// GetStateRangeScanIterator returns an iterator that contains all the key-values between given key ranges.
	// startKey is inclusive
	// endKey is exclusive
	// The returned ResultsIterator contains results of type *VersionedKV
	GetStateRangeScanIterator(namespace string, startKey string, endKey string) (ResultsIterator, error)
	// GetStateRangeScanIteratorWithPagination returns an iterator that contains all the key-values between given key ranges.
	// startKey is inclusive
	// endKey is exclusive
	// pageSize parameter limits the number of returned results
	// The returned ResultsIterator contains results of type *VersionedKV
	GetStateRangeScanIteratorWithPagination(namespace string, startKey string, endKey string, pageSize int32) (QueryResultsIterator, error)
	// ExecuteQuery executes the given query and returns an iterator that contains results of type *VersionedKV.
	ExecuteQuery(namespace, query string) (ResultsIterator, error)
	// ExecuteQueryWithPagination executes the given query and
	// returns an iterator that contains results of type *VersionedKV.
	// The bookmark and page size parameters are associated with the pagination query.
	ExecuteQueryWithPagination(namespace, query, bookmark string, pageSize int32) (QueryResultsIterator, error)
	// ApplyUpdates applies the batch to the underlying db.
	// height is the height of the highest transaction in the Batch that
	// a state db implementation is expected to ues as a save point
	ApplyUpdates(batch *UpdateBatch, height *version.Height) error
	// GetLatestSavePoint returns the height of the highest transaction upto which
	// the state db is consistent
	GetLatestSavePoint() (*version.Height, error)
	// ValidateKeyValue tests whether the key and value is supported by the db implementation.
	// For instance, leveldb supports any bytes for the key while the couchdb supports only valid utf-8 string
	// TODO make the function ValidateKeyValue return a specific error say ErrInvalidKeyValue
	// However, as of now, the both implementations of this function (leveldb and couchdb) are deterministic in returing an error
	// i.e., an error is returned only if the key-value are found to be invalid for the underlying db
	ValidateKeyValue(key string, value []byte) error
	// BytesKeySupported returns true if the implementation (underlying db) supports the any bytes to be used as key.
	// For instance, leveldb supports any bytes for the key while the couchdb supports only valid utf-8 string
	BytesKeySupported() bool
	// GetFullScanIterator returns a FullScanIterator that can be used to iterate over entire data in the statedb.
	// `skipNamespace` parameter can be used to control if the consumer wants the FullScanIterator
	// to skip one or more namespaces from the returned results. The second parameter returns the format information
	// about the value bytes returned by the Next function in the returned FullScanIterator.
	// The intended use of this iterator is to generate the snapshot files for the statedb.
	GetFullScanIterator(skipNamespace func(string) bool) (FullScanIterator, byte, error)
	// Open opens the db
	Open() error
	// Close closes the db
	Close()
}

VersionedDB lists methods that a db is supposed to implement

type VersionedDBProvider

type VersionedDBProvider interface {
	// GetDBHandle returns a handle to a VersionedDB
	GetDBHandle(id string, namespaceProvider NamespaceProvider) (VersionedDB, error)
	// Close closes all the VersionedDB instances and releases any resources held by VersionedDBProvider
	Close()
}

VersionedDBProvider provides an instance of an versioned DB

type VersionedKV

type VersionedKV struct {
	CompositeKey
	VersionedValue
}

VersionedKV encloses key and corresponding VersionedValue

type VersionedValue

type VersionedValue struct {
	Value    []byte
	Metadata []byte
	Version  *version.Height
}

VersionedValue encloses value and corresponding version

func (*VersionedValue) IsDelete

func (vv *VersionedValue) IsDelete() bool

IsDelete returns true if this update indicates delete of a key