PHPLIB-45: Collection enumeration methods

src/Database.php

@@ -5,9 +5,14 @@ namespace MongoDB;
 use MongoDB\Collection;
 use MongoDB\Driver\Command;
 use MongoDB\Driver\Manager;
+use MongoDB\Driver\Query;
 use MongoDB\Driver\ReadPreference;
 use MongoDB\Driver\Result;
 use MongoDB\Driver\WriteConcern;
+use MongoDB\Model\CollectionInfoIterator;
+use MongoDB\Model\CollectionInfoCommandIterator;
+use MongoDB\Model\CollectionInfoLegacyIterator;
+use InvalidArgumentException;
 
 class Database
 {
@@ -84,11 +89,12 @@ class Database
      *
      * @see http://docs.mongodb.org/manual/reference/command/listCollections/
      * @param array $options
-     * @return Result
+     * @return CollectionInfoIterator
      */
     public function listCollections(array $options = array())
     {
-        // TODO
+        // TODO: Determine if command or legacy method should be used
+        return $this->listCollectionsCommand($options);
     }
 
     /**
@@ -110,4 +116,58 @@ class Database
 
         return new Collection($this->manager, $namespace, $writeConcern, $readPreference);
     }
+
+    /**
+     * Returns information for all collections in this database using the
+     * listCollections command.
+     *
+     * @param array $options
+     * @return CollectionInfoCommandIterator
+     */
+    private function listCollectionsCommand(array $options = array())
+    {
+        $command = new Command(array('listCollections' => 1) + $options);
+        // TODO: Relax RP if connected to a secondary node in standalone mode
+        $readPreference = new ReadPreference(ReadPreference::RP_PRIMARY);
+
+        $result = $this->manager->executeCommand($this->databaseName, $command, $readPreference);
+
+        return new CollectionInfoCommandIterator($result);
+    }
+
+    /**
+     * Returns information for all collections in this database by querying
+     * the "system.namespaces" collection (MongoDB <2.8).
+     *
+     * @param array $options
+     * @return CollectionInfoLegacyIterator
+     * @throws InvalidArgumentException if the filter option is neither an array
+     *                                  nor object, or if filter.name is not a
+     *                                  string.
+     */
+    private function listCollectionsLegacy(array $options = array())
+    {
+        $filter = array_key_exists('filter', $options) ? $options['filter'] : array();
+
+        if ( ! is_array($filter) && ! is_object($filter)) {
+            throw new InvalidArgumentException(sprintf('Expected filter to be array or object, %s given', gettype($filter)));
+        }
+
+        if (array_key_exists('name', $filter)) {
+            if ( ! is_string($filter['name'])) {
+                throw new InvalidArgumentException(sprintf('Filter "name" must be a string for MongoDB <2.8, %s given', gettype($filter['name'])));
+            }
+
+            $filter['name'] = $this->databaseName . '.' . $filter['name'];
+        }
+
+        $namespace = $this->databaseName . '.system.namespaces';
+        $query = new Query($filter);
+        // TODO: Relax RP if connected to a secondary node in standalone mode
+        $readPreference = new ReadPreference(ReadPreference::RP_PRIMARY);
+
+        $result = $this->manager->executeQuery($namespace, $query, $readPreference);
+
+        return new CollectionInfoLegacyIterator($result);
+    }
 }

src/Model/CollectionInfo.php

+<?php
+
+namespace MongoDB\Model;
+
+class CollectionInfo
+{
+    private $name;
+    private $options;
+
+    /**
+    * Constructor.
+    *
+    * @param array $info Collection info
+    */
+    public function __construct(array $info)
+    {
+        $this->name = (string) $info['name'];
+        $this->options = isset($info['options']) ? (array) $info['options'] : array();
+    }
+
+    /**
+     * Return the collection name.
+     *
+     * @return string
+     */
+    public function getName()
+    {
+        return $this->name;
+    }
+
+    /**
+     * Return the collection options.
+     *
+     * @return array
+     */
+    public function getOptions()
+    {
+        return $this->options;
+    }
+
+    /**
+     * Return whether the collection is a capped collection.
+     *
+     * @return boolean
+     */
+    public function isCapped()
+    {
+        return isset($this->options['capped']) ? (boolean) $this->options['capped'] : false;
+    }
+
+    /**
+     * Return the maximum number of documents to keep in the capped collection.
+     *
+     * @return integer|null
+     */
+    public function getCappedMax()
+    {
+        return isset($this->options['max']) ? (integer) $this->options['max'] : null;
+    }
+
+    /**
+     * Return the maximum size (in bytes) of the capped collection.
+     *
+     * @return integer|null
+     */
+    public function getCappedSize()
+    {
+        return isset($this->options['size']) ? (integer) $this->options['size'] : null;
+    }
+}

src/Model/CollectionInfoCommandIterator.php

+<?php
+
+namespace MongoDB\Model;
+
+use IteratorIterator;
+
+class CollectionInfoCommandIterator extends IteratorIterator implements CollectionInfoIterator
+{
+    /**
+     * Return the current element as a CollectionInfo instance.
+     *
+     * @return CollectionInfo
+     */
+    public function current()
+    {
+        return new CollectionInfo(parent::current());
+    }
+}

src/Model/CollectionInfoIterator.php

+<?php
+
+namespace MongoDB\Model;
+
+use Iterator;
+
+interface CollectionInfoIterator extends Iterator
+{
+    /**
+     * Return the current element as a CollectionInfo instance.
+     *
+     * @return CollectionInfo
+     */
+    public function current();
+}

src/Model/CollectionInfoLegacyIterator.php

+<?php
+
+namespace MongoDB\Model;
+
+use FilterIterator;
+
+class CollectionInfoLegacyIterator extends FilterIterator implements CollectionInfoIterator
+{
+    /**
+     * Return the current element as a CollectionInfo instance.
+     *
+     * @return CollectionInfo
+     */
+    public function current()
+    {
+        $info = parent::current();
+
+        // Trim the database prefix up to and including the first dot
+        $firstDot = strpos($info['name'], '.');
+
+        if ($firstDot !== false) {
+            $info['name'] = (string) substr($info['name'], $firstDot + 1);
+        }
+
+        return new CollectionInfo($info);
+    }
+
+    /**
+     * Filter out internal or invalid collections.
+     *
+     * @see http://php.net/manual/en/filteriterator.accept.php
+     * @return boolean
+     */
+    public function accept()
+    {
+        $info = parent::current();
+
+        if ( ! isset($info['name']) || ! is_string($info['name'])) {
+            return false;
+        }
+
+        // Reject names with "$" characters (e.g. indexes, oplog)
+        if (strpos($info['name'], '$') !== false) {
+            return false;
+        }
+
+        $firstDot = strpos($info['name'], '.');
+
+        /* Legacy collection names are a namespace and should be prefixed with
+         * the database name and a dot. Reject values that omit this prefix or
+         * are empty beyond it.
+         */
+        if ($firstDot === false || $firstDot + 1 == strlen($info['name'])) {
+            return false;
+        }
+
+        return true;
+    }
+}

tests/DatabaseFunctionalTest.php

@@ -39,4 +39,24 @@ class DatabaseFunctionalTest extends FunctionalTestCase
         $this->assertCommandSucceeded($commandResult);
         $this->assertCollectionCount($this->getNamespace(), 0);
     }
+
+    public function testListCollections()
+    {
+        $writeResult = $this->manager->executeInsert($this->getNamespace(), array('x' => 1));
+        $this->assertEquals(1, $writeResult->getInsertedCount());
+
+        $collections = $this->database->listCollections();
+        $this->assertInstanceOf('MongoDB\Model\CollectionInfoIterator', $collections);
+
+        $foundCollection = null;
+
+        foreach ($collections as $collection) {
+            if ($collection->getName() === $this->getCollectionName()) {
+                $foundCollection = $collection;
+                break;
+            }
+        }
+
+        $this->assertNotNull($foundCollection, 'Found test collection in list of collection');
+    }
 }