1 files changed, 88 insertions, 22 deletions
diff --git a/phpBB/includes/acp/acp_database.php b/phpBB/includes/acp/acp_database.php
index 1842ecd98f..9361b00f5b 100644
--- a/phpBB/includes/acp/acp_database.php
+++ b/phpBB/includes/acp/acp_database.php
@@ -625,23 +625,25 @@ class mysql_extractor extends base_extractor
 			{
 				$field_set[] = $field[$j]->name;
 			}
-		
+
 			$search			= array("\\", "'", "\x00", "\x0a", "\x0d", "\x1a", '"');
 			$replace		= array("\\\\", "\\'", '\0', '\n', '\r', '\Z', '\\"');
 			$fields			= implode(', ', $field_set);
 			$sql_data		= 'INSERT INTO ' . $table_name . ' (' . $fields . ') VALUES ';
 			$first_set		= true;
+			$query_len		= 0;
+			$max_len		= get_usable_memory();
 		
 			while ($row = mysqli_fetch_row($result))
 			{
 				$values	= array();
 				if ($first_set)
 				{
-					$sql_data .= '(';
+					$query = $sql_data . '(';
 				}
 				else
 				{
-					$sql_data  .= ',(';
+					$query  .= ',(';
 				}
 
 				for ($j = 0; $j < $fields_cnt; $j++)
@@ -659,18 +661,27 @@ class mysql_extractor extends base_extractor
 						$values[$j] = "'" . str_replace($search, $replace, $row[$j]) . "'";
 					}
 				}
-				$sql_data .= implode(', ', $values) . ')';
-
-				$this->flush($sql_data);
+				$query .= implode(', ', $values) . ')';
 
-				$sql_data = '';
-				$first_set = false;
+				$query_len += strlen($query);
+				if ($query_len > $max_len)
+				{
+					$this->flush($query . ";\n\n");
+					$query = '';
+					$query_len = 0;
+					$first_set = true;
+				}
+				else
+				{
+					$first_set = false;
+				}
 			}
 			mysqli_free_result($result);
 
-			if (!$first_set)
+			// check to make sure we have nothing left to flush
+			if (!$first_set && $query)
 			{
-				$this->flush(";\n\n");
+				$this->flush($query . ";\n\n");
 			}
 		}
 	}
@@ -702,20 +713,21 @@ class mysql_extractor extends base_extractor
 			$search			= array("\\", "'", "\x00", "\x0a", "\x0d", "\x1a", '"');
 			$replace		= array("\\\\", "\\'", '\0', '\n', '\r', '\Z', '\\"');
 			$fields			= implode(', ', $field_set);
-			$sql_data	= 'INSERT INTO ' . $table_name . ' (' . $fields . ') VALUES ';
-
-			$first_set = true;
+			$sql_data		= 'INSERT INTO ' . $table_name . ' (' . $fields . ') VALUES ';
+			$first_set		= true;
+			$query_len		= 0;
+			$max_len		= get_usable_memory();
 
 			while ($row = mysql_fetch_row($result))
 			{
 				$values = array();
 				if ($first_set)
 				{
-					$sql_data .= '(';
+					$query = $sql_data . '(';
 				}
 				else
 				{
-					$sql_data  .= ',(';
+					$query  .= ',(';
 				}
 
 				for ($j = 0; $j < $fields_cnt; $j++)
@@ -733,18 +745,27 @@ class mysql_extractor extends base_extractor
 						$values[$j] = "'" . str_replace($search, $replace, $row[$j]) . "'";
 					}
 				}
-				$sql_data .= implode(', ', $values) . ')';
-
-				$this->flush($sql_data);
+				$query .= implode(', ', $values) . ')';
 
-				$sql_data = '';
-				$first_set = false;
+				$query_len += strlen($query);
+				if ($query_len > $max_len)
+				{
+					$this->flush($query . ";\n\n");
+					$query = '';
+					$query_len = 0;
+					$first_set = true;
+				}
+				else
+				{
+					$first_set = false;
+				}
 			}
 			mysql_free_result($result);
 
-			if (!$first_set)
+			// check to make sure we have nothing left to flush
+			if (!$first_set && $query)
 			{
-				$this->flush(";\n\n");
+				$this->flush($query . ";\n\n");
 			}
 		}
 	}
@@ -2061,6 +2082,51 @@ class firebird_extractor extends base_extractor
 	}
 }
 
+// get how much space we allow for a chunk of data, very similar to phpMyAdmin's way of doing things ;-) (hey, we only do this for MySQL anyway :P)
+function get_usable_memory()
+{
+	$val = trim(@ini_get('memory_limit'));
+
+	if (preg_match('/(\\d+)([mkg]?)/i', $val, $regs))
+	{
+		$memory_limit = (int) $regs[1];
+		switch ($regs[2])
+		{
+
+			case 'k':
+			case 'K':
+				$memory_limit *= 1024;
+			break;
+
+			case 'm':
+			case 'M':
+				$memory_limit *= 1048576;
+			break;
+
+			case 'g':
+			case 'G':
+				$memory_limit *= 1073741824;
+			break;
+		}
+
+		// how much memory PHP requires at the start of export (it is really a little less)
+		if ($memory_limit > 6100000)
+		{
+			$memory_limit -= 6100000;
+		}
+
+		// allow us to consume half of the total memory available
+		$memory_limit /= 2;
+	}
+	else
+	{
+		// set the buffer to 1M if we have no clue how much memory PHP will give us :P
+		$memory_limit = 1048576;
+	}
+
+	return $memory_limit;
+}
+
 function sanitize_data_mssql($text)
 {
 	$data = preg_split('/[\n\t\r\b\f]/', $text);