Add a method to set/unset multiple config values in one call

This reduces the number of file writes we do for config.php and therefor
hopefully helps lowering the chances for empty config.php files

lib/private/allconfig.php

@@ -69,6 +69,16 @@ class AllConfig implements \OCP\IConfig {
 		}
 	}
 
+	/**
+	 * Sets and deletes system wide values
+	 *
+	 * @param array $configs Associative array with `key => value` pairs
+	 *                       If value is null, the config key will be deleted
+	 */
+	public function setSystemValues(array $configs) {
+		$this->systemConfig->setValues($configs);
+	}
+
 	/**
 	 * Sets a new system wide value
 	 *

lib/private/config.php

@@ -41,10 +41,10 @@ class Config {
 
 	/**
 	 * Lists all available config keys
-	 * @return array an array of key names
 	 *
-	 * This function returns all keys saved in config.php. Please note that it
-	 * does not return the values.
+	 * Please note that it does not return the values.
+	 *
+	 * @return array an array of key names
 	 */
 	public function getKeys() {
 		return array_keys($this->cache);
@@ -52,12 +52,12 @@ class Config {
 
 	/**
 	 * Gets a value from config.php
+	 *
+	 * If it does not exist, $default will be returned.
+	 *
 	 * @param string $key key
 	 * @param mixed $default = null default value
 	 * @return mixed the value or $default
-	 *
-	 * This function gets the value from config.php. If it does not exist,
-	 * $default will be returned.
 	 */
 	public function getValue($key, $default = null) {
 		if (isset($this->cache[$key])) {
@@ -68,38 +68,83 @@ class Config {
 	}
 
 	/**
-	 * Sets a value
-	 * @param string $key key
-	 * @param mixed $value value
-	 *
-	 * This function sets the value and writes the config.php.
+	 * Sets and deletes values and writes the config.php
 	 *
+	 * @param array $configs Associative array with `key => value` pairs
+	 *                       If value is null, the config key will be deleted
 	 */
-	public function setValue($key, $value) {
-		// Add change
-		$this->cache[$key] = $value;
-
-		// Write changes
-		$this->writeData();
-	}
-
-	/**
-	 * Removes a key from the config
-	 * @param string $key key
-	 *
-	 * This function removes a key from the config.php.
-	 *
-	 */
-	public function deleteKey($key) {
-		if (isset($this->cache[$key])) {
-			// Delete key from cache
-			unset($this->cache[$key]);
+	public function setValues(array $configs) {
+		$needsUpdate = false;
+		foreach ($configs as $key => $value) {
+			if ($value !== null) {
+				$needsUpdate |= $this->set($key, $value);
+			} else {
+				$needsUpdate |= $this->delete($key);
+			}
+		}
 
+		if ($needsUpdate) {
 			// Write changes
 			$this->writeData();
 		}
 	}
 
+	/**
+	 * Sets the value and writes it to config.php if required
+	 *
+	 * @param string $key key
+	 * @param mixed $value value
+	 */
+	public function setValue($key, $value) {
+		if ($this->set($key, $value)) {
+			// Write changes
+			$this->writeData();
+		}
+	}
+
+	/**
+	 * This function sets the value
+	 *
+	 * @param string $key key
+	 * @param mixed $value value
+	 * @return bool True if the file needs to be updated, false otherwise
+	 */
+	protected function set($key, $value) {
+		if (!isset($this->cache[$key]) || $this->cache[$key] !== $value) {
+			// Add change
+			$this->cache[$key] = $value;
+			return true;
+		}
+
+		return false;
+	}
+
+	/**
+	 * Removes a key from the config and removes it from config.php if required
+	 * @param string $key
+	 */
+	public function deleteKey($key) {
+		if ($this->delete($key)) {
+			// Write changes
+			$this->writeData();
+		}
+	}
+
+	/**
+	 * This function removes a key from the config
+	 *
+	 * @param string $key
+	 * @return bool True if the file needs to be updated, false otherwise
+	 */
+	protected function delete($key) {
+		if (isset($this->cache[$key])) {
+			// Delete key from cache
+			unset($this->cache[$key]);
+			return true;
+		}
+		return false;
+	}
+
 	/**
 	 * Loads the config file
 	 *

lib/private/legacy/config.php

@@ -58,6 +58,16 @@ class OC_Config {
 		self::$object->setValue($key, $value);
 	}
 
+	/**
+	 * Sets and deletes values and writes the config.php
+	 *
+	 * @param array $configs Associative array with `key => value` pairs
+	 *                       If value is null, the config key will be deleted
+	 */
+	public static function setValues(array $configs) {
+		self::$object->setValues($configs);
+	}
+
 	/**
 	 * Removes a key from the config
 	 * @param string $key key

lib/private/systemconfig.php

@@ -27,6 +27,16 @@ class SystemConfig {
 		\OC_Config::setValue($key, $value);
 	}
 
+	/**
+	 * Sets and deletes values and writes the config.php
+	 *
+	 * @param array $configs Associative array with `key => value` pairs
+	 *                       If value is null, the config key will be deleted
+	 */
+	public function setValues(array $configs) {
+		\OC_Config::setValues($configs);
+	}
+
 	/**
 	 * Looks up a system wide defined value
 	 *

lib/public/iconfig.php

@@ -34,6 +34,14 @@ namespace OCP;
  * Access to all the configuration options ownCloud offers
  */
 interface IConfig {
+	/**
+	 * Sets and deletes system wide values
+	 *
+	 * @param array $configs Associative array with `key => value` pairs
+	 *                       If value is null, the config key will be deleted
+	 */
+	public function setSystemValues(array $configs);
+
 	/**
 	 * Sets a new system wide value
 	 *

tests/lib/config.php

@@ -71,6 +71,36 @@ class Test_Config extends \Test\TestCase {
 		$this->assertEquals($expected, $content);
 	}
 
+	public function testSetValues() {
+		$content = file_get_contents($this->configFile);
+		$this->assertEquals(self::TESTCONTENT, $content);
+
+		// Changing configs to existing values and deleting non-existing once
+		// should not rewrite the config.php
+		$this->config->setValues([
+			'foo'			=> 'bar',
+			'not_exists'	=> null,
+		]);
+
+		$this->assertAttributeEquals($this->initialConfig, 'cache', $this->config);
+		$content = file_get_contents($this->configFile);
+		$this->assertEquals(self::TESTCONTENT, $content);
+
+		$this->config->setValues([
+			'foo'			=> 'moo',
+			'alcohol_free'	=> null,
+		]);
+		$expectedConfig = $this->initialConfig;
+		$expectedConfig['foo'] = 'moo';
+		unset($expectedConfig['alcohol_free']);
+		$this->assertAttributeEquals($expectedConfig, 'cache', $this->config);
+
+		$content = file_get_contents($this->configFile);
+		$expected = "<?php\n\$CONFIG = array (\n  'foo' => 'moo',\n  'beers' => \n  array (\n    0 => 'Appenzeller',\n  " .
+			"  1 => 'Guinness',\n    2 => 'Kölsch',\n  ),\n);\n";
+		$this->assertEquals($expected, $content);
+	}
+
 	public function testDeleteKey() {
 		$this->config->deleteKey('foo');
 		$expectedConfig = $this->initialConfig;