/**
* This performs a table alter, but does it unbuffered so the script can time out professionally.
*
* @param string $change
* @param int $substep
* @param boolean $is_test
*/
function protected_alter($change, $substep, $is_test = false)
{
global $db_prefix;
$table = db_table();
$db = database();
// Firstly, check whether the current index/column exists.
$found = false;
if ($change['type'] === 'column') {
$columns = $table->db_list_columns('{db_prefix}' . $change['table'], true);
foreach ($columns as $column) {
// Found it?
if ($column['name'] === $change['name']) {
$found |= 1;
// Do some checks on the data if we have it set.
if (isset($change['col_type'])) {
$found &= $change['col_type'] === $column['type'];
}
if (isset($change['null_allowed'])) {
$found &= $column['null'] == $change['null_allowed'];
}
if (isset($change['default'])) {
$found &= $change['default'] === $column['default'];
}
}
}
} elseif ($change['type'] === 'index') {
$request = upgrade_query('
SHOW INDEX
FROM ' . $db_prefix . $change['table']);
if ($request !== false) {
$cur_index = array();
while ($row = $db->fetch_assoc($request)) {
if ($row['Key_name'] === $change['name']) {
$cur_index[(int) $row['Seq_in_index']] = $row['Column_name'];
}
}
ksort($cur_index, SORT_NUMERIC);
$found = array_values($cur_index) === $change['target_columns'];
$db->free_result($request);
}
}
// If we're trying to add and it's added, we're done.
if ($found && in_array($change['method'], array('add', 'change'))) {
return true;
} elseif (!$found && in_array($change['method'], array('remove', 'change_remove'))) {
return true;
} elseif ($is_test) {
return false;
}
// Not found it yet? Bummer! How about we see if we're currently doing it?
$running = false;
$found = false;
while (1 == 1) {
$request = upgrade_query('
SHOW FULL PROCESSLIST');
while ($row = $db->fetch_assoc($request)) {
if (strpos($row['Info'], 'ALTER TABLE ' . $db_prefix . $change['table']) !== false && strpos($row['Info'], $change['text']) !== false) {
$found = true;
}
}
// Can't find it? Then we need to run it fools!
if (!$found && !$running) {
$db->free_result($request);
$success = upgrade_query('
ALTER TABLE ' . $db_prefix . $change['table'] . '
' . $change['text'], true) !== false;
if (!$success) {
return false;
}
// Return
$running = true;
} elseif (!$found) {
$db->free_result($request);
return true;
}
// Pause execution for a sec or three.
sleep(3);
// Can never be too well protected.
nextSubstep($substep);
}
// Protect it.
nextSubstep($substep);
}
function textfield_alter($change, $substep)
{
global $db_prefix;
// Versions of MySQL < 4.1 wouldn't benefit from character set detection.
if (version_compare('4.1.0', preg_replace('~\\-.+?$~', '', min(mysql_get_server_info(), mysql_get_client_info()))) > 0) {
$column_fix = true;
$null_fix = !$change['null_allowed'];
} else {
$request = upgrade_query("\n\t\t\tSHOW FULL COLUMNS \n\t\t\tFROM {$db_prefix}{$change['table']}\n\t\t\tLIKE '{$change['column']}'");
if (mysql_num_rows($request) === 0) {
die('Unable to find column ' . $change['column'] . ' inside table ' . $db_prefix . $change['table']);
}
$table_row = mysql_fetch_assoc($request);
mysql_free_result($request);
// If something of the current column definition is different, fix it.
$column_fix = $table_row['Type'] !== $change['type'] || (strtolower($table_row['Null']) === 'yes') !== $change['null_allowed'] || ($table_row['Default'] == NULL) !== !isset($change['default']) || isset($change['default']) && $change['default'] !== $table_row['Default'];
// Columns that previously allowed null, need to be converted first.
$null_fix = strtolower($table_row['Null']) === 'yes' && !$change['null_allowed'];
// Get the character set that goes with the collation of the column.
if ($column_fix && !empty($table_row['Collation'])) {
$request = upgrade_query("\n\t\t\t\tSHOW COLLATION\n\t\t\t\tLIKE '{$table_row['Collation']}'");
// No results? Just forget it all together.
if (mysql_num_rows($request) === 0) {
unset($table_row['Collation']);
} else {
$collation_info = mysql_fetch_assoc($request);
}
mysql_free_result($request);
}
}
if ($column_fix) {
// Make sure there are no NULL's left.
if ($null_fix) {
upgrade_query("\n\t\t\t\tUPDATE {$db_prefix}{$change['table']}\n\t\t\t\tSET {$change['column']} = '" . (isset($change['default']) ? addslashes($change['default']) : '') . "'\n\t\t\t\tWHERE {$change['column']} IS NULL");
}
// Do the actual alteration.
upgrade_query("\n\t\t\tALTER TABLE {$db_prefix}{$change['table']}\n\t\t\tCHANGE COLUMN {$change['column']} {$change['column']} {$change['type']}" . (isset($collation_info['Charset']) ? " CHARACTER SET {$collation_info['Charset']} COLLATE {$collation_info['Collation']}" : '') . ($change['null_allowed'] ? '' : ' NOT NULL') . (isset($change['default']) ? " default '" . addslashes($change['default']) . "'" : ''));
}
nextSubstep($substep);
}
