Document MongoDB\Driver\ReadConcern::LINEARIZABLE constant

https://jira.mongodb.org/browse/PHPC-777


git-svn-id: https://svn.php.net/repository/phpdoc/en/trunk@340579 c90b9560-bf6c-de11-be94-00142212c4b1

reference/mongodb/mongodb/driver/readconcern.xml

@@ -35,6 +35,12 @@
     </classsynopsisinfo>
 <!-- }}} -->
     <classsynopsisinfo role="comment">Constants</classsynopsisinfo>
+    <fieldsynopsis>
+     <modifier>const</modifier>
+     <type>string</type>
+     <varname linkend="mongodb-driver-readconcern.constants.linearizable">MongoDB\Driver\ReadConcern::LINEARIZABLE</varname>
+     <initializer>linearizable</initializer>
+    </fieldsynopsis>
     <fieldsynopsis>
      <modifier>const</modifier>
      <type>string</type>
@@ -60,6 +66,21 @@
    &reftitle.constants;
    <variablelist>
 
+    <varlistentry xml:id="mongodb-driver-readconcern.constants.linearizable">
+     <term><constant>MongoDB\Driver\ReadConcern::LINEARIZABLE</constant></term>
+     <listitem>
+      <para>
+       A linearizable read avoids returning reads from a
+       <emphasis>stale</emphasis> primary (one that has already been superseded
+       by a new primary but doesn&apos;t know it yet). It is important to note
+       that this read concern level does not by itself produce linearizable
+       reads; they must be issued in conjunction with
+       <constant>MongoDB\Driver\WriteConcern::MAJORITY</constant> writes to the
+       same document(s) in order to be linearizable.
+      </para>
+     </listitem>
+    </varlistentry>
+
     <varlistentry xml:id="mongodb-driver-readconcern.constants.local">
      <term><constant>MongoDB\Driver\ReadConcern::LOCAL</constant></term>
      <listitem>
@@ -89,6 +110,30 @@
   </section>
 <!-- }}} -->
 
+  <section role="changelog">
+   &reftitle.changelog;
+   <para>
+    <informaltable>
+     <tgroup cols="2">
+      <thead>
+       <row>
+        <entry>&Version;</entry>
+        <entry>&Description;</entry>
+       </row>
+      </thead>
+      <tbody>
+       <row>
+        <entry>1.2.0</entry>
+        <entry>
+         Added the <constant>MongoDB\Driver\ReadConcern::LINEARIZABLE</constant>
+         constant.
+        </entry>
+       </row>
+      </tbody>
+     </tgroup>
+    </informaltable>
+   </para>
+  </section>
 
  </partintro>