--- /dev/null
+<?php
+/*
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+ * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+ * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+ * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+ * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+ * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+ * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+ * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+ * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+ * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+ * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ *
+ * This software consists of voluntary contributions made by many individuals
+ * and is licensed under the MIT license. For more information, see
+ * <http://www.doctrine-project.org>.
+ */
+
+namespace Doctrine\DBAL\Id;
+
+use Doctrine\DBAL\DriverManager;
+use Doctrine\DBAL\Connection;
+
+/**
+ * Table ID Generator for those poor languages that are missing sequences.
+ *
+ * WARNING: The Table Id Generator clones a second independent database
+ * connection to work correctly. This means using the generator requests that
+ * generate IDs will have two open database connections. This is necessary to
+ * be safe from transaction failures in the main connection. Make sure to only
+ * ever use one TableGenerator otherwise you end up with many connections.
+ *
+ * TableID Generator does not work with SQLite.
+ *
+ * The TableGenerator does not take care of creating the SQL Table itself. You
+ * should look at the `TableGeneratorSchemaVisitor` to do this for you.
+ * Otherwise the schema for a table looks like:
+ *
+ * CREATE sequences (
+ * sequence_name VARCHAR(255) NOT NULL,
+ * sequence_value INT NOT NULL DEFAULT '1',
+ * sequence_increment_by INT NOT NULL DEFAULT '1',
+ * PRIMARY KEY (table_name)
+ * );
+ *
+ * Technically this generator works as follows:
+ *
+ * 1. Use a robust transaction serialization level.
+ * 2. Open transaction
+ * 3. Acquire a read lock on the table row (SELECT .. FOR UPDATE)
+ * 4. Increment current value by one and write back to database
+ * 5. Commit transaction
+ *
+ * If you are using a sequence_increment_by value that is larger than one the
+ * ID Generator will keep incrementing values until it hits the incrementation
+ * gap before issuing another query.
+ *
+ * If no row is present for a given sequence a new one will be created with the
+ * default values 'value' = 1 and 'increment_by' = 1
+ *
+ * @author Benjamin Eberlei <kontakt@beberlei.de>
+ */
+class TableGenerator
+{
+ /**
+ * @var \Doctrine\DBAL\Connection
+ */
+ private $conn;
+
+ /**
+ * @var string
+ */
+ private $generatorTableName;
+
+ /**
+ * @var array
+ */
+ private $sequences = array();
+
+ /**
+ * @param Connection $conn
+ * @param string $generatorTableName
+ */
+ public function __construct(Connection $conn, $generatorTableName = 'sequences')
+ {
+ $params = $conn->getParams();
+ if ($params['driver'] == 'pdo_sqlite') {
+ throw new \Doctrine\DBAL\DBALException("Cannot use TableGenerator with SQLite.");
+ }
+ $this->conn = DriverManager::getConnection($params, $conn->getConfiguration(), $conn->getEventManager());
+ $this->generatorTableName = $generatorTableName;
+ }
+
+ /**
+ * Generate the next unused value for the given sequence name
+ *
+ * @param string
+ * @return int
+ */
+ public function nextValue($sequenceName)
+ {
+ if (isset($this->sequences[$sequenceName])) {
+ $value = $this->sequences[$sequenceName]['value'];
+ $this->sequences[$sequenceName]['value']++;
+ if ($this->sequences[$sequenceName]['value'] >= $this->sequences[$sequenceName]['max']) {
+ unset ($this->sequences[$sequenceName]);
+ }
+ return $value;
+ }
+
+ $this->conn->beginTransaction();
+
+ try {
+ $platform = $this->conn->getDatabasePlatform();
+ $sql = "SELECT sequence_value, sequence_increment_by " .
+ "FROM " . $platform->appendLockHint($this->generatorTableName, \Doctrine\DBAL\LockMode::PESSIMISTIC_WRITE) . " " .
+ "WHERE sequence_name = ? " . $platform->getWriteLockSQL();
+ $stmt = $this->conn->executeQuery($sql, array($sequenceName));
+
+ if ($row = $stmt->fetch(\PDO::FETCH_ASSOC)) {
+ $row = array_change_key_case($row, CASE_LOWER);
+
+ $value = $row['sequence_value'];
+ $value++;
+
+ if ($row['sequence_increment_by'] > 1) {
+ $this->sequences[$sequenceName] = array(
+ 'value' => $value,
+ 'max' => $row['sequence_value'] + $row['sequence_increment_by']
+ );
+ }
+
+ $sql = "UPDATE " . $this->generatorTableName . " ".
+ "SET sequence_value = sequence_value + sequence_increment_by " .
+ "WHERE sequence_name = ? AND sequence_value = ?";
+ $rows = $this->conn->executeUpdate($sql, array($sequenceName, $row['sequence_value']));
+
+ if ($rows != 1) {
+ throw new \Doctrine\DBAL\DBALException("Race-condition detected while updating sequence. Aborting generation");
+ }
+ } else {
+ $this->conn->insert(
+ $this->generatorTableName,
+ array('sequence_name' => $sequenceName, 'sequence_value' => 1, 'sequence_increment_by' => 1)
+ );
+ $value = 1;
+ }
+
+ $this->conn->commit();
+
+ } catch(\Exception $e) {
+ $this->conn->rollback();
+ throw new \Doctrine\DBAL\DBALException("Error occured while generating ID with TableGenerator, aborted generation: " . $e->getMessage(), 0, $e);
+ }
+
+ return $value;
+ }
+}
+
projects / zf2.biz / application_blanche.git / blobdiff