Create functions.php file for utility functions

composer.json

@@ -13,7 +13,8 @@
         "ext-mongodb": ">=0.6.0"
     },
     "autoload": {
-        "psr-4": { "MongoDB\\": "src/" }
+        "psr-4": { "MongoDB\\": "src/" },
+        "files": [ "src/functions.php" ]
     },
     "extra": {
         "branch-alias": {

src/functions.php

+<?php
+
+namespace MongoDB;
+
+use MongoDB\Driver\Server;
+use MongoDB\Exception\InvalidArgumentTypeException;
+
+/**
+ * Return whether the first key in the document starts with a "$" character.
+ *
+ * This is used for differentiating update and replacement documents.
+ *
+ * @internal
+ * @param array|object $document Update or replacement document
+ * @return boolean
+ * @throws InvalidArgumentTypeException
+ */
+function is_first_key_operator($document)
+{
+    if (is_object($document)) {
+        $document = get_object_vars($document);
+    }
+
+    if ( ! is_array($document)) {
+        throw new InvalidArgumentTypeException('$document', $document, 'array or object');
+    }
+
+    $firstKey = (string) key($document);
+
+    return (isset($firstKey[0]) && $firstKey[0] == '$');
+}
+
+/**
+ * Generate an index name from a key specification.
+ *
+ * @internal
+ * @param array|object $document Document containing fields mapped to values,
+ *                               which denote order or an index type
+ * @return string
+ * @throws InvalidArgumentTypeException
+ */
+function generate_index_name($document)
+{
+    if (is_object($document)) {
+        $document = get_object_vars($document);
+    }
+
+    if ( ! is_array($document)) {
+        throw new InvalidArgumentTypeException('$document', $document, 'array or object');
+    }
+
+    $name = '';
+
+    foreach ($document as $field => $type) {
+        $name .= ($name != '' ? '_' : '') . $field . '_' . $type;
+    }
+
+    return $name;
+}
+
+/**
+ * Return whether the server supports a particular feature.
+ *
+ * @internal
+ * @param Server  $server  Server to check
+ * @param integer $feature Feature constant (i.e. wire protocol version)
+ * @return boolean
+ */
+function server_supports_feature(Server $server, $feature)
+{
+    $info = $server->getInfo();
+    $maxWireVersion = isset($info['maxWireVersion']) ? (integer) $info['maxWireVersion'] : 0;
+    $minWireVersion = isset($info['minWireVersion']) ? (integer) $info['minWireVersion'] : 0;
+
+    return ($minWireVersion <= $feature && $maxWireVersion >= $feature);
+}

tests/PedantryTest.php

@@ -62,6 +62,10 @@ class PedantryTest extends \PHPUnit_Framework_TestCase
         $files = new RegexIterator(new RecursiveIteratorIterator(new RecursiveDirectoryIterator($srcDir)), '/\.php$/i');
 
         foreach ($files as $file) {
+            if ($file->getFilename() === 'functions.php') {
+                continue;
+            }
+
             $classNames[][] = 'MongoDB\\' . str_replace(DIRECTORY_SEPARATOR, '\\', substr($file->getRealPath(), strlen($srcDir) + 1, -4));
         }