Merge branch '0.9.x' of git@gitorious.org:statusnet/mainline into 0.9.x

1 files changed, 169 insertions, 0 deletions

diff --git a/lib/columndef.php b/lib/columndef.php
new file mode 100644
index 000000000..1bae6b33b
--- /dev/null
+++ b/lib/columndef.php
@@ -0,0 +1,169 @@
+<?php
+/**
+ * StatusNet, the distributed open-source microblogging tool
+ *
+ * Database schema utilities
+ *
+ * PHP version 5
+ *
+ * LICENCE: This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU Affero General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU Affero General Public License for more details.
+ *
+ * You should have received a copy of the GNU Affero General Public License
+ * along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ *
+ * @category  Database
+ * @package   StatusNet
+ * @author    Evan Prodromou <evan@status.net>
+ * @copyright 2009 StatusNet, Inc.
+ * @license   http://www.fsf.org/licensing/licenses/agpl-3.0.html GNU Affero General Public License version 3.0
+ * @link      http://status.net/
+ */
+
+if (!defined('STATUSNET')) {
+    exit(1);
+}
+
+/**
+ * A class encapsulating the structure of a column in a table.
+ *
+ * @category Database
+ * @package  StatusNet
+ * @author   Evan Prodromou <evan@status.net>
+ * @license  http://www.fsf.org/licensing/licenses/agpl-3.0.html GNU Affero General Public License version 3.0
+ * @link     http://status.net/
+ */
+
+class ColumnDef
+{
+    /** name of the column. */
+    public $name;
+    /** type of column, e.g. 'int', 'varchar' */
+    public $type;
+    /** size of the column. */
+    public $size;
+    /** boolean flag; can it be null? */
+    public $nullable;
+    /**
+     * type of key: null = no key; 'PRI' => primary;
+     * 'UNI' => unique key; 'MUL' => multiple values.
+     */
+    public $key;
+    /** default value if any. */
+    public $default;
+    /** 'extra' stuff. Returned by MySQL, largely
+     * unused. */
+    public $extra;
+    /** auto increment this field if no value is specific for it during an insert **/
+    public $auto_increment;
+
+    /**
+     * Constructor.
+     *
+     * @param string  $name     name of the column
+     * @param string  $type     type of the column
+     * @param int     $size     size of the column
+     * @param boolean $nullable can this be null?
+     * @param string  $key      type of key
+     * @param value   $default  default value
+     * @param value   $extra    unused
+     */
+
+    function __construct($name=null, $type=null, $size=null,
+                         $nullable=true, $key=null, $default=null,
+                         $extra=null, $auto_increment=false)
+    {
+        $this->name     = strtolower($name);
+        $this->type     = strtolower($type);
+        $this->size     = $size+0;
+        $this->nullable = $nullable;
+        $this->key      = $key;
+        $this->default  = $default;
+        $this->extra    = $extra;
+        $this->auto_increment = $auto_increment;
+    }
+
+    /**
+     * Compares this columndef with another to see
+     * if they're functionally equivalent.
+     *
+     * @param ColumnDef $other column to compare
+     *
+     * @return boolean true if equivalent, otherwise false.
+     */
+
+    function equals($other)
+    {
+        return ($this->name == $other->name &&
+                $this->_typeMatch($other) &&
+                $this->_defaultMatch($other) &&
+                $this->_nullMatch($other) &&
+                $this->key == $other->key &&
+                $this->auto_increment == $other->auto_increment);
+    }
+
+    /**
+     * Does the type of this column match the
+     * type of the other column?
+     *
+     * Checks the type and size of a column. Tries
+     * to ignore differences between synonymous
+     * data types, like 'integer' and 'int'.
+     *
+     * @param ColumnDef $other other column to check
+     *
+     * @return boolean true if they're about equivalent
+     */
+
+    private function _typeMatch($other)
+    {
+        switch ($this->type) {
+        case 'integer':
+        case 'int':
+            return ($other->type == 'integer' ||
+                    $other->type == 'int');
+            break;
+        default:
+            return ($this->type == $other->type &&
+                    $this->size == $other->size);
+        }
+    }
+
+    /**
+     * Does the default behaviour of this column match
+     * the other?
+     *
+     * @param ColumnDef $other other column to check
+     *
+     * @return boolean true if defaults are effectively the same.
+     */
+
+    private function _defaultMatch($other)
+    {
+        return ((is_null($this->default) && is_null($other->default)) ||
+                ($this->default == $other->default));
+    }
+
+    /**
+     * Does the null behaviour of this column match
+     * the other?
+     *
+     * @param ColumnDef $other other column to check
+     *
+     * @return boolean true if these columns 'null' the same.
+     */
+
+    private function _nullMatch($other)
+    {
+        return ((!is_null($this->default) && !is_null($other->default) &&
+                 $this->default == $other->default) ||
+                ($this->nullable == $other->nullable));
+    }
+}