pegasus

package
v0.0.0-...-ba0e684 Latest Latest
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 Go to latest Published: May 19, 2022 License: Apache-2.0 Imports: 19 Imported by: 35

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Index

Constants

View Source 
const (
	CheckTypeNoCheck = CheckType(rrdb.CasCheckType_CT_NO_CHECK)

	// existence
	CheckTypeValueNotExist        = CheckType(rrdb.CasCheckType_CT_VALUE_NOT_EXIST)          // value is not exist
	CheckTypeValueNotExistOrEmpty = CheckType(rrdb.CasCheckType_CT_VALUE_NOT_EXIST_OR_EMPTY) // value is not exist or value is empty
	CheckTypeValueExist           = CheckType(rrdb.CasCheckType_CT_VALUE_EXIST)              // value is exist
	CheckTypeValueNotEmpty        = CheckType(rrdb.CasCheckType_CT_VALUE_NOT_EMPTY)          // value is exist and not empty

	// match
	CheckTypeMatchAnywhere = CheckType(rrdb.CasCheckType_CT_VALUE_MATCH_ANYWHERE) // operand matches anywhere in value
	CheckTypeMatchPrefix   = CheckType(rrdb.CasCheckType_CT_VALUE_MATCH_PREFIX)   // operand matches prefix in value
	CheckTypeMatchPostfix  = CheckType(rrdb.CasCheckType_CT_VALUE_MATCH_POSTFIX)  // operand matches postfix in value

	// bytes compare
	CheckTypeBytesLess           = CheckType(rrdb.CasCheckType_CT_VALUE_BYTES_LESS)             // bytes compare: value < operand
	CheckTypeBytesLessOrEqual    = CheckType(rrdb.CasCheckType_CT_VALUE_BYTES_LESS_OR_EQUAL)    // bytes compare: value <= operand
	CheckTypeBytesEqual          = CheckType(rrdb.CasCheckType_CT_VALUE_BYTES_EQUAL)            // bytes compare: value == operand
	CheckTypeBytesGreaterOrEqual = CheckType(rrdb.CasCheckType_CT_VALUE_BYTES_GREATER_OR_EQUAL) // bytes compare: value >= operand
	CheckTypeBytesGreater        = CheckType(rrdb.CasCheckType_CT_VALUE_BYTES_GREATER)          // bytes compare: value > operand

	// int compare: first transfer bytes to int64; then compare by int value
	CheckTypeIntLess           = CheckType(rrdb.CasCheckType_CT_VALUE_INT_LESS)             // int compare: value < operand
	CheckTypeIntLessOrEqual    = CheckType(rrdb.CasCheckType_CT_VALUE_INT_LESS_OR_EQUAL)    // int compare: value <= operand
	CheckTypeIntEqual          = CheckType(rrdb.CasCheckType_CT_VALUE_INT_EQUAL)            // int compare: value == operand
	CheckTypeIntGreaterOrEqual = CheckType(rrdb.CasCheckType_CT_VALUE_INT_GREATER_OR_EQUAL) // int compare: value >= operand
	CheckTypeIntGreater        = CheckType(rrdb.CasCheckType_CT_VALUE_BYTES_GREATER)        // int compare: value > operand
)

The value checking types

View Source 
const (
	FilterTypeNoFilter      = FilterType(rrdb.FilterType_FT_NO_FILTER)
	FilterTypeMatchAnywhere = FilterType(rrdb.FilterType_FT_MATCH_ANYWHERE)
	FilterTypeMatchPrefix   = FilterType(rrdb.FilterType_FT_MATCH_PREFIX)
	FilterTypeMatchPostfix  = FilterType(rrdb.FilterType_FT_MATCH_POSTFIX)
)

Filter types

Variables

View Source 
var DefaultMultiGetOptions = &MultiGetOptions{
	StartInclusive: true,
	StopInclusive:  false,
	SortKeyFilter: Filter{
		Type:    FilterTypeNoFilter,
		Pattern: nil,
	},
	MaxFetchCount: 100,
	MaxFetchSize:  100000,
	NoValue:       false,
}

DefaultMultiGetOptions defines the defaults of MultiGetOptions.

Functions

func WrapError 

func WrapError(err error, op OpType) error

WrapError wraps up the internal errors for ensuring that all types of errors returned by public interfaces are pegasus.PError.

Types

type CheckAndSetOptions 

type CheckAndSetOptions struct {
	SetValueTTLSeconds int  // time to live in seconds of the set value, 0 means no ttl.
	ReturnCheckValue   bool // if return the check value in results.
}

CheckAndSetOptions is the options of a CAS.

type CheckAndSetResult 

type CheckAndSetResult struct {
	// true if set value succeed.
	SetSucceed bool

	// the actual value if set value failed; null means the actual value is not exist.
	CheckValue []byte

	// if the check value is exist; can be used only when checkValueReturned is true.
	CheckValueExist bool

	// return the check value if exist; can be used only when checkValueExist is true.
	CheckValueReturned bool
}

CheckAndSetResult is the result of a CAS.

type CheckType 

type CheckType int

CheckType defines the types of value checking in a CAS.

type Client 

type Client interface {
	Close() error

	// Open the specific pegasus table. If the table was opened before,
	// it will reuse the previous connection to the table.
	OpenTable(ctx context.Context, tableName string) (TableConnector, error)
}

Client manages the client sessions to the pegasus cluster specified by `Config`. In order to reuse the previous connections, it's recommended to use one singleton client in your program. The operations upon a client instance are thread-safe.

func NewClient 

func NewClient(cfg Config) Client

NewClient creates a new instance of pegasus client. It panics if the configured addresses are illegal.

type CompositeKey 

type CompositeKey struct {
	HashKey, SortKey []byte
}

CompositeKey is a composition of HashKey and SortKey.

type Config 

type Config struct {
	MetaServers []string `json:"meta_servers"`
}

Config is the configuration of pegasus client.

type Filter 

type Filter struct {
	Type    FilterType
	Pattern []byte
}

Filter is used to filter based on the key.

type FilterType 

type FilterType int

FilterType defines the type of key filtering.

type KeyValue 

type KeyValue struct {
	SortKey, Value []byte
}

KeyValue is the returned type of MultiGet and MultiGetRange.

type MultiGetOptions 

type MultiGetOptions struct {
	StartInclusive bool
	StopInclusive  bool
	SortKeyFilter  Filter

	// Max count of k-v pairs to be fetched. MaxFetchCount <= 0 means no limit.
	MaxFetchCount int

	// Max size of k-v pairs to be fetched. MaxFetchSize <= 0 means no limit.
	MaxFetchSize int

	// Query order
	Reverse bool

	// Whether to retrieve keys only, without value.
	// Enabling this option will reduce the network load, improve the RPC latency.
	NoValue bool
}

MultiGetOptions is the options for MultiGet and MultiGetRange, defaults to DefaultMultiGetOptions.

type OpType 

type OpType int

OpType is the type of operation that led to PError. 

const (
	OpQueryConfig OpType = iota
	OpGet
	OpSet
	OpDel
	OpMultiDel
	OpMultiGet
	OpMultiGetRange
	OpClose
	OpMultiSet
	OpTTL
	OpExist
	OpGetScanner
	OpGetUnorderedScanners
	OpNext
	OpScannerClose
	OpCheckAndSet
	OpSortKeyCount
	OpIncr
	OpBatchGet
)

Operation types

func (OpType) String 

func (op OpType) String() string

type PError 

type PError struct {
	// Err is the error that occurred during the operation.
	Err error

	// The failed operation
	Op OpType
}

PError is the return error type of all interfaces of pegasus client.

func (*PError) Error 

func (e *PError) Error() string

type Scanner 

type Scanner interface {
	// Grabs the next entry.
	Next(ctx context.Context) (completed bool, hashKey []byte, sortKey []byte, value []byte, err error)

	Close() error
}

Scanner defines the interface of client-side scanning.

type ScannerOptions 

type ScannerOptions struct {
	BatchSize      int  // internal buffer batch size
	StartInclusive bool // if the startSortKey is included
	StopInclusive  bool // if the stopSortKey is included
	HashKeyFilter  Filter
	SortKeyFilter  Filter
	NoValue        bool // only fetch hash_key and sort_key, but not fetch value
}

ScannerOptions is the options for GetScanner and GetUnorderedScanners.

func NewScanOptions 

func NewScanOptions() *ScannerOptions

NewScanOptions returns the default ScannerOptions.

type TableConnector 

type TableConnector interface {
	// Get retrieves the entry for `hashKey` + `sortKey`.
	// Returns nil if no entry matches.
	// `hashKey` : CAN'T be nil or empty.
	// `sortKey` : CAN'T be nil but CAN be empty.
	Get(ctx context.Context, hashKey []byte, sortKey []byte) ([]byte, error)

	// Set the entry for `hashKey` + `sortKey` to `value`.
	// If Set is called or `ttl` == 0, no data expiration is specified.
	// `hashKey` : CAN'T be nil or empty.
	// `sortKey` / `value` : CAN'T be nil but CAN be empty.
	Set(ctx context.Context, hashKey []byte, sortKey []byte, value []byte) error
	SetTTL(ctx context.Context, hashKey []byte, sortKey []byte, value []byte, ttl time.Duration) error

	// Delete the entry for `hashKey` + `sortKey`.
	// `hashKey` : CAN'T be nil or empty.
	// `sortKey` : CAN'T be nil but CAN be empty.
	Del(ctx context.Context, hashKey []byte, sortKey []byte) error

	// MultiGet/MultiGetOpt retrieves the multiple entries for `hashKey` + `sortKeys[i]` atomically in one operation.
	// MultiGet is identical to MultiGetOpt except that the former uses DefaultMultiGetOptions as `options`.
	//
	// If `sortKeys` are given empty or nil, all entries under `hashKey` will be retrieved.
	// `hashKey` : CAN'T be nil or empty.
	// `sortKeys[i]` : CAN'T be nil but CAN be empty.
	//
	// The returned key-value pairs are sorted by sort key in ascending order.
	// Returns nil if no entries match.
	// Returns true if all data is fetched, false if only partial data is fetched.
	//
	MultiGet(ctx context.Context, hashKey []byte, sortKeys [][]byte) ([]*KeyValue, bool, error)
	MultiGetOpt(ctx context.Context, hashKey []byte, sortKeys [][]byte, options *MultiGetOptions) ([]*KeyValue, bool, error)

	// MultiGetRange retrieves the multiple entries under `hashKey`, between range (`startSortKey`, `stopSortKey`),
	// atomically in one operation.
	//
	// startSortKey: nil or len(startSortKey) == 0 means start from begin.
	// stopSortKey: nil or len(stopSortKey) == 0 means stop to end.
	// `hashKey` : CAN'T be nil.
	//
	// The returned key-value pairs are sorted by sort keys in ascending order.
	// Returns nil if no entries match.
	// Returns true if all data is fetched, false if only partial data is fetched.
	//
	MultiGetRange(ctx context.Context, hashKey []byte, startSortKey []byte, stopSortKey []byte) ([]*KeyValue, bool, error)
	MultiGetRangeOpt(ctx context.Context, hashKey []byte, startSortKey []byte, stopSortKey []byte, options *MultiGetOptions) ([]*KeyValue, bool, error)

	// MultiSet sets the multiple entries for `hashKey` + `sortKeys[i]` atomically in one operation.
	// `hashKey` / `sortKeys` / `values` : CAN'T be nil or empty.
	// `sortKeys[i]` / `values[i]` : CAN'T be nil but CAN be empty.
	MultiSet(ctx context.Context, hashKey []byte, sortKeys [][]byte, values [][]byte) error
	MultiSetOpt(ctx context.Context, hashKey []byte, sortKeys [][]byte, values [][]byte, ttl time.Duration) error

	// MultiDel deletes the multiple entries under `hashKey` all atomically in one operation.
	// `hashKey` / `sortKeys` : CAN'T be nil or empty.
	// `sortKeys[i]` : CAN'T be nil but CAN be empty.
	MultiDel(ctx context.Context, hashKey []byte, sortKeys [][]byte) error

	// Returns ttl(time-to-live) in seconds: -1 if ttl is not set; -2 if entry doesn't exist.
	// `hashKey` : CAN'T be nil or empty.
	// `sortKey` : CAN'T be nil but CAN be empty.
	TTL(ctx context.Context, hashKey []byte, sortKey []byte) (int, error)

	// Check value existence for the entry for `hashKey` + `sortKey`.
	// `hashKey`: CAN'T be nil or empty.
	Exist(ctx context.Context, hashKey []byte, sortKey []byte) (bool, error)

	// Get Scanner for {startSortKey, stopSortKey} within hashKey.
	// startSortKey: nil or len(startSortKey) == 0 means start from begin.
	// stopSortKey: nil or len(stopSortKey) == 0 means stop to end.
	// `hashKey`: CAN'T be nil or empty.
	GetScanner(ctx context.Context, hashKey []byte, startSortKey []byte, stopSortKey []byte, options *ScannerOptions) (Scanner, error)

	// Get Scanners for all data in pegasus, the count of scanners will
	// be no more than maxSplitCount
	GetUnorderedScanners(ctx context.Context, maxSplitCount int, options *ScannerOptions) ([]Scanner, error)

	// Atomically check and set value by key from the cluster. The value will be set if and only if check passed.
	// The sort key for checking and setting can be the same or different.
	//
	// `checkSortKey`: The sort key for checking.
	// `setSortKey`: The sort key for setting.
	// `checkOperand`:
	CheckAndSet(ctx context.Context, hashKey []byte, checkSortKey []byte, checkType CheckType,
		checkOperand []byte, setSortKey []byte, setValue []byte, options *CheckAndSetOptions) (*CheckAndSetResult, error)

	// Returns the count of sortkeys under hashkey.
	// `hashKey`: CAN'T be nil or empty.
	SortKeyCount(ctx context.Context, hashKey []byte) (int64, error)

	// Atomically increment value by key from the cluster.
	// Returns the new value.
	// `hashKey` / `sortKeys` : CAN'T be nil or empty
	Incr(ctx context.Context, hashKey []byte, sortKey []byte, increment int64) (int64, error)

	// Gets values from a batch of CompositeKeys. Internally it distributes each key
	// into a Get call and wait until all returned.
	//
	// `keys`: CAN'T be nil or empty, `hashkey` in `keys` can't be nil or empty either.
	// The returned values are in sequence order of each key, aka `keys[i] => values[i]`.
	// If keys[i] is not found, or the Get failed, values[i] is set nil.
	//
	// Returns a non-nil `err` once there's a failed Get call. It doesn't mean all calls failed.
	//
	// NOTE: this operation is not guaranteed to be atomic
	BatchGet(ctx context.Context, keys []CompositeKey) (values [][]byte, err error)

	Close() error
}

TableConnector is used to communicate with single Pegasus table.

func ConnectTable 

func ConnectTable(ctx context.Context, tableName string, meta *session.MetaManager, replica *session.ReplicaManager) (TableConnector, error)

ConnectTable queries for the configuration of the given table, and set up connection to the replicas which the table locates on.

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