Class used to manage connections to Spanner.
**You don't need to use this class directly, connections will be handled for you.**
{EventEmitter}
Inheritance
EventEmitter > SessionPoolPackage
@google-cloud/spannerConstructors
(constructor)(database, options)
constructor(database: Database, options?: SessionPoolOptions);
Constructs a new instance of the SessionPool
class
Parameters | |
---|---|
Name | Description |
database |
Database
The DB instance. |
options |
SessionPoolOptions
Configuration options. |
Properties
_acquires
_acquires: PQueue;
_evictHandle
_evictHandle: NodeJS.Timer;
_inventory
_inventory: SessionInventory;
_onClose
_onClose: Promise<void>;
_pending
_pending: number;
_pingHandle
_pingHandle: NodeJS.Timer;
_requests
_requests: PQueue;
_traces
_traces: Map<string, trace.StackFrame[]>;
_waiters
_waiters: number;
available
get available(): number;
Total number of available sessions. {number}
borrowed
get borrowed(): number;
Total number of borrowed sessions. {number}
currentWriteFraction
get currentWriteFraction(): number;
database
database: Database;
isFull
get isFull(): boolean;
Flag to determine if Pool is full. {boolean}
isOpen
isOpen: boolean;
numReadWaiters
get numReadWaiters(): number;
numWriteWaiters
get numWriteWaiters(): number;
options
options: SessionPoolOptions;
pendingPrepare
get pendingPrepare(): number;
reads
get reads(): number;
size
get size(): number;
Total size of pool. {number}
totalPending
get totalPending(): number;
Number of sessions being created or prepared for a read/write transaction. {number}
totalWaiters
get totalWaiters(): number;
Sum of read and write waiters. {number}
writes
get writes(): number;
Methods
_acquire()
_acquire(): Promise<Session>;
Attempts to borrow a session from the pool.
Returns | |
---|---|
Type | Description |
Promise<Session> | {Promise
|
_borrow(session)
_borrow(session: Session): void;
Moves a session into the borrowed group.
Parameter | |
---|---|
Name | Description |
session |
Session
The session object. |
Returns | |
---|---|
Type | Description |
void |
_borrowFrom()
_borrowFrom(): Session;
Borrows the first session from the inventory.
{Session}
Returns | |
---|---|
Type | Description |
Session |
_borrowNextAvailableSession()
_borrowNextAvailableSession(): Session;
Grabs the next available session.
Returns | |
---|---|
Type | Description |
Session | {Promise
|
_createSession()
_createSession(): Promise<void>;
Attempts to create a single session.
Returns | |
---|---|
Type | Description |
Promise<void> | {Promise} |
_createSessions(amount)
_createSessions(amount: number): Promise<void>;
Batch creates sessions.
Parameter | |
---|---|
Name | Description |
amount |
number
Config specifying how many sessions to create. |
Returns | |
---|---|
Type | Description |
Promise<void> | {Promise} SessionPool#createError |
_destroy(session)
_destroy(session: Session): Promise<void>;
Attempts to delete a session, optionally creating a new one of the same type if the pool is still open and we're under the configured min value.
SessionPool#error
Parameter | |
---|---|
Name | Description |
session |
Session
The session to delete. |
Returns | |
---|---|
Type | Description |
Promise<void> | {Promise} |
_evictIdleSessions()
_evictIdleSessions(): void;
Deletes idle sessions that exceed the maxIdle configuration.
Returns | |
---|---|
Type | Description |
void |
_fill()
_fill(): Promise<void>;
Fills the pool with the minimum number of sessions.
{Promise}
Returns | |
---|---|
Type | Description |
Promise<void> |
_getIdleSessions()
_getIdleSessions(): Session[];
Retrieves a list of all the idle sessions.
Returns | |
---|---|
Type | Description |
Session[] | {Session[]} |
_getLeaks()
_getLeaks(): string[];
Returns stack traces for sessions that have not been released.
{string[]}
Returns | |
---|---|
Type | Description |
string[] |
_getSession(startTime)
_getSession(startTime: number): Promise<Session>;
Attempts to get a session.
Parameter | |
---|---|
Name | Description |
startTime |
number
Timestamp to use when determining timeouts. |
Returns | |
---|---|
Type | Description |
Promise<Session> | {Promise
|
_hasSessionUsableFor()
_hasSessionUsableFor(): boolean;
Returns true if the pool has a usable session.
Returns | |
---|---|
Type | Description |
boolean |
_isValidSession(session)
_isValidSession(session: Session): boolean;
Checks to see whether or not session is expired.
Parameter | |
---|---|
Name | Description |
session |
Session
The session to check. |
Returns | |
---|---|
Type | Description |
boolean | {boolean} |
_ping(session)
_ping(session: Session): Promise<void>;
Pings an individual session.
Parameter | |
---|---|
Name | Description |
session |
Session
The session to ping. |
Returns | |
---|---|
Type | Description |
Promise<void> | {Promise} |
_pingIdleSessions()
_pingIdleSessions(): Promise<void>;
Makes a keep alive request to all the idle sessions.
Returns | |
---|---|
Type | Description |
Promise<void> | {Promise} |
_prepareTransaction(session)
_prepareTransaction(session: Session): void;
Creates a transaction for a session.
Parameter | |
---|---|
Name | Description |
session |
Session
The session object. |
Returns | |
---|---|
Type | Description |
void |
_release(session)
_release(session: Session): void;
Releases a session back into the pool.
SessionPool#available SessionPool#session-available
Parameter | |
---|---|
Name | Description |
session |
Session
The session object. |
Returns | |
---|---|
Type | Description |
void |
_startHouseKeeping()
_startHouseKeeping(): void;
Starts housekeeping (pinging/evicting) of idle sessions.
Returns | |
---|---|
Type | Description |
void |
_stopHouseKeeping()
_stopHouseKeeping(): void;
Stops housekeeping.
Returns | |
---|---|
Type | Description |
void |
close(callback)
close(callback: SessionPoolCloseCallback): void;
Closes and the pool.
SessionPool#close
Parameter | |
---|---|
Name | Description |
callback |
SessionPoolCloseCallback
The callback function. |
Returns | |
---|---|
Type | Description |
void |
formatTrace(frames)
static formatTrace(frames: trace.StackFrame[]): string;
Formats stack trace objects into Node-like stack trace.
Parameter | |
---|---|
Name | Description |
frames |
StackFrame[]
|
Returns | |
---|---|
Type | Description |
string |
getReadSession(callback)
getReadSession(callback: GetReadSessionCallback): void;
Retrieve a read session.
Parameter | |
---|---|
Name | Description |
callback |
GetReadSessionCallback
The callback function. |
Returns | |
---|---|
Type | Description |
void |
getSession(callback)
getSession(callback: GetSessionCallback): void;
Retrieve a session.
Parameter | |
---|---|
Name | Description |
callback |
GetSessionCallback
The callback function. |
Returns | |
---|---|
Type | Description |
void |
getWriteSession(callback)
getWriteSession(callback: GetWriteSessionCallback): void;
Retrieve a read/write session.
Parameter | |
---|---|
Name | Description |
callback |
GetWriteSessionCallback
The callback function. |
Returns | |
---|---|
Type | Description |
void |
open()
open(): void;
Opens the pool, filling it to the configured number of read and write sessions.
SessionPool#open {Promise}
Returns | |
---|---|
Type | Description |
void |
release(session)
release(session: Session): void;
Releases session back into the pool.
Parameter | |
---|---|
Name | Description |
session |
Session
The session to release. |
Returns | |
---|---|
Type | Description |
void |