copy_master

#! /usr/bin/env php
<?php

// script to manage copy tasks
//
// copy_master args
// --init: clear in_progress flags (do at boot time)
// --daemon: run as a daemon
// --sleep_interval: if daemon, how long to sleep between scans
// --retry_interval: how long to wait until retry failed copy (sec)
// default: start tasks as needed, then exit

require_once("hera_util.inc");
require_once("hl_db.inc");

$sleep_interval = 10;
$retry_interval = 60;

// clear the in_progress flag of uncompleted tasks
//
function init() {
    task_update_all("in_progress=0", "completed=0");
    echo "reset ".affected_rows()." tasks\n";
}

// spawn a process to handle a task
//
function start_task($task) {
    task_update($task->id, "in_progress=1");
    $pid = pcntl_fork();
    if (!$pid) {
        $cmd = "./copier --task_id $task->id";
        system($cmd);
        exit(0);
    }
}

// enumerate tasks (up to the config limit) and handle them
//
function start_tasks() {
    global $retry_interval, $config;

    if ($config->max_transfers) {
        $count = table_count("task", "in_progress<>0");
        $limit = $config->max_transfers - $count;
        if ($limit <= 0) {
            echo "at max_transfer limit; not starting new copies\n";
            return;
        } else {
            echo "limit: $limit new copies\n";
        }
    } else {
        $limit = 9999;
    }

    $t = time() - $retry_interval;
    $tasks = task_enum("completed=0 and in_progress=0 and last_error_time<$t limit $limit");
    if (!$tasks) {
        echo "no tasks to run\n";
        return;
    }
    foreach ($tasks as $task) {
        echo "starting task $task->id\n";
        start_task($task);
    }
}

// if run as daemon: repeatedly scan for tasks
//
function daemon() {
    global $sleep_interval;
    while (1) {
        start_tasks();
        // reap any child processes
        //
        while (1) {
            $ret = pcntl_wait($status, WNOHANG);
            if ($ret > 0) continue;
            break;
        }
        sleep($sleep_interval);
    }
}

$daemon = false;

$config = get_server_config();
if (!init_db($config)) {
    die("can't open DB\n");
}

for ($i=1; $i<$argc; $i++) {
    switch ($argv[$i]) {
    case "--init":
        init();
        exit;
    case "--daemon":
        $daemon = true;
        break;
    case "--sleep_interval":
        $sleep_interval = (int)($argv[++$argc]);
        break;
    case "--retry_interval":
        $retry_interval = (int)($argv[++$argc]);
        break;
    default:
        echo "bad arg: ".$argv[$i]."\n";
    }
}

if ($daemon) {
    daemon();
} else {
    start_tasks();
}

?>