Create a new WriteConcern

# MongoDB\Driver\WriteConcern::__construct

(mongodb >=1.0.0)

MongoDB\Driver\WriteConcern::__construct — Create a new WriteConcern

### 説明

final public MongoDB\Driver\WriteConcern::__construct ( string|integer `$w` [, int `$wtimeout` [, bool `$journal` ]] )

Constructs a new MongoDB\Driver\WriteConcern, which is an immutable value object.

### パラメータ

`w`

  Write concern
  Value | Description
  --- | ---
  1 | Requests acknowledgement that the write operation has propagated to the standalone mongod or the primary in a replica set. This is the default write concern for MongoDB.
  0 | Requests no acknowledgment of the write operation. However, this may return information about socket exceptions and networking errors to the application.
  <integer greater than 1> | Numbers greater than 1 are valid only for replica sets to request acknowledgement from specified number of members, including the primary.
  `MongoDB\Driver\WriteConcern::MAJORITY` | Requests acknowledgment that write operations have propagated to the majority of voting nodes, including the primary, and have been written to the on-disk journal for these nodes. Prior to MongoDB 3.0, this refers to the majority of replica set members (not just voting nodes).
  string | A string value is interpereted as a tag set. Requests acknowledgement that the write operations have propagated to a replica set member with the specified tag.

`wtimeout`

  How long to wait (in milliseconds) for secondaries before failing.

  wtimeout causes write operations to return with an error (WriteConcernError) after the specified limit, even if the required write concern will eventually succeed. When these write operations return, MongoDB does not undo successful data modifications performed before the write concern exceeded the wtimeout time limit.

  If specified, wtimeout must be a signed 32-bit integer greater than or equal to zero.

  Write concern timeout
  Value | Description
  --- | ---
  0 | Block indefinitely. This is the default.
  <integer greater than 0> | Milliseconds to wait until returning.

`journal`

  Wait until mongod has applied the write to the journal.

### エラー / 例外

- 引数のパースに失敗した場合に MongoDB\Driver\Exception\InvalidArgumentException をスローします。
- Throws MongoDB\Driver\Exception\InvalidArgumentException if `w` is invalid or `wtimeout` is either negative or greater than the bounds of a signed 32-bit integer.

### 例

例1 MongoDB\Driver\WriteConcern::__construct() example

`<?php
/* Request write acknowledgement from the majority of the replica set nodes */
$wc = new MongoDB\Driver\WriteConcern(MongoDB\Driver\WriteConcern::MAJORITY, 500);
/* Request write acknowledgement from a node configured with the "MultipleDC" tag */
$wc = new MongoDB\Driver\WriteConcern("MultipleDC", 500);
?>`

### 参考

- » Write Concern reference