mysql-dump-file-splitter.php

<?php
// php mysql-dump-file-splitter.php bigdump.sql
//    outputs dump files in ./out/
// php mysql-dump-file-splitter.php bigdump.sql dryrun
//    does not output dump files but runs through the process

// options
define('OUTPUT_DIR', __DIR__ . DIRECTORY_SEPARATOR . 'out' . DIRECTORY_SEPARATOR);
$memlimit   = '96'/*MB*/ * 1024 * 1024;
$skiptables = explode(',', 'users'); // skips users table

// preparation
$res        = fopen(__DIR__ . DIRECTORY_SEPARATOR . $_SERVER['argv'][1], 'r');
$groupcount = -1;
$count      = 1;
$groups     = [];
$filecount  = 1;
$tablenames = [];
$firstlines = [];

/**
 * Outputs new SQL dump file
 */
function dumpgroups(&$groups, &$filecount, &$tablenames)
{
    if (isset($_SERVER['argv'][2]) && $_SERVER['argv'][2] === 'dryrun') {
        return;
    }
    foreach ($groups as $number => $group) {
        if (!isset($tablenames[$number])) {
            continue;
        }
        if ($group) {
            $path = OUTPUT_DIR . $tablenames[$number] . '-' . $filecount++ . '.sql';
            file_put_contents($path, $group);
            echo 'writing ' . $path . PHP_EOL;
            $groups[$number] = '';
        }
    }
}

// parses SQL
while (($line = fgets($res)) != false) {
    $count++;
    if (isset($_SERVER['argv'][2]) && $_SERVER['argv'][2] === 'dryrun' && strpos($line, 'Table structure for tabl') !== false) {
        echo $line;
    }
    if (
        preg_match('/^-- Table structure for table \`(.+?)\`$/i', trim($line), $matches, PREG_OFFSET_CAPTURE) === 1 ||
        preg_match('/^-- Dump completed on/i', trim($line), $matches) === 1
    ) {
        if (isset($tablenames[$groupcount])) {
            dumpgroups($groups, $filecount, $tablenames);
        }
        if (!isset($matches[1][0])) {
            break;
        }
        $tablename                 = $matches[1][0];
        $tablenames[++$groupcount] = $tablename;
        $firstlines[$groupcount]   = $count;
        if (!in_array($tablename, $skiptables)) {
            echo 'reading table ' . $tablename . PHP_EOL;
        }
    }
    if (!isset($groups[$groupcount])) {
        $groups[$groupcount] = '';
    }
    if (isset($tablenames[$groupcount]) && in_array($tablenames[$groupcount], $skiptables)) {
        if (isset($firstlines[$groupcount]) && $firstlines[$groupcount] === $count) {
            echo 'skipped table ' . $tablenames[$groupcount] . PHP_EOL;
        }
        continue;
    }
    $groups[$groupcount] .= $line;
    if (memory_get_usage(true) >= $memlimit) {
        dumpgroups($groups, $filecount, $tablenames);
    }
}
fclose($res);
echo 'END';