PHP 从多维数组 (IMAP) 创建消息线程的多维数组

Question

我的问题如下：

如果您往下看，您会看到有一个带有消息 ID 的数据结构，然后是包含消息详细信息的最终数据结构，该数据结构应该从 imap_fetch_overview 聚合。消息 ID 来自imap_thread。问题在于它没有将电子邮件详细信息放在消息 ID 所在的位置。

这是我的数据结构：

[5] => Array
    (
        [0] => 5
        [1] => 9
    )

[10] => Array
    (
        [0] => 10
        [1] => 11
    )

我想要的是：

[5] => Array
    (
        [0] => messageDetails for id 5
        [1] => messageDetails for id 9
    )

[10] => Array
    (
        [0] => messageDetails for id 10
        [1] => messageDetails for id 11
    )

这是我到目前为止的代码：

$emails = imap_fetch_overview($imap, implode(',',$ids));

// root is the array index position of the threads message, such as 5 or 10
foreach($threads as $root => $messages){

    // id is the id being given to us from `imap_thread`
    foreach($message as $key => $id){

      foreach($emails as $index => $email){

         if($id === $email->msgno){
             $threads[$root][$key] = $email;
             break;
          }
      }
    }
 }

这是其中一封 $email 的打印输出：

    [0] => stdClass Object
    (
        [subject] => Cloud Storage Dump
        [from] => Josh Doe
        [to] => jondoe@domain.com
        [date] => Mon, 21 Jan 2013 23:18:00 -0500
        [message_id] => <50FE12F8.9050506@domain.com>
        [size] => 2559
        [uid] => 5
        [msgno] => 5
        [recent] => 0
        [flagged] => 0
        [answered] => 1
        [deleted] => 0
        [seen] => 0
        [draft] => 0
        [udate] => 1358828308
    )

如果您注意到，msgno 是 5，这与 $id 相关，因此从技术上讲，数据应该填充到最终数据结构中。

此外，这似乎是一种低效的处理方式。

如果您需要任何其他说明，请告诉我。

更新代码

此代码是我在 php api 上找到的代码和我的一些修复的组合。我认为有问题的仍然是$root。

$addedEmails = array();
$thread = imap_thread($imap);
foreach ($thread as $i => $messageId) { 
    list($sequence, $type) = explode('.', $i); 
    //if type is not num or messageId is 0 or (start of a new thread and no next) or is already set 
   if($type != 'num' || $messageId == 0 || ($root == 0 && $thread[$sequence.'.next'] == 0) || isset($rootValues[$messageId])) { 
    //ignore it 
    continue; 
} 

if(in_array($messageId, $addedEmails)){
    continue;
}
array_push($addedEmails,$messageId);

//if this is the start of a new thread 
if($root == 0) { 
    //set root 
    $root = $messageId; 
} 

//at this point this will be part of a thread 
//let's remember the root for this email 
$rootValues[$messageId] = $root; 

//if there is no next 
if($thread[$sequence.'.next'] == 0) { 
    //reset root 
    $root = 0; 
    } 
  }
$ids=array();
$threads = array();
foreach($rootValues as $id => $root){
    if(!array_key_exists($root,$threads)){
        $threads[$root] = array();
    }
    if(!in_array($id,$threads[$root])){
        $threads[$root][] = $id;
       $ids[]=$id;
    }
 }
 $emails = imap_fetch_overview($imap, implode(',', array_keys($rootValues)));

 $keys = array();
 foreach($emails as $k => $email)
 {
$keys[$email->msgno] = $k;
 }

 $threads = array_map(function($thread) use($emails, $keys)
{
// Iterate emails in these threads
return array_map(function($msgno) use($emails, $keys)
{
    // Swap the msgno with the email details
    return $emails[$keys[$msgno]];

}, $thread);
}, $threads);

Answer 1

当你 print_r 的 $emails 数组你得到什么结构？也许下面应该这样做？

 $threads[$root][$key] = $emails[$key];

Answer 2

我现在无法访问 PHP 进行测试，但我相信您正在尝试做的事情类似于

foreach($emails as $email) {
    foreach($threads as $root => $messages) {
        foreach($messages as $index =>$message_id){
            if($message_id == $email->msgno){
                 $threads[$root][$index] = $email;
            }
        }
    }
}

话虽如此，即使这样可行，也可能有比使用三个嵌套循环更有效的方法来解决这个问题。您需要以这种格式存储输出的原因是什么？

Answer 3

请记住，在 php 中，您使用的任何函数最终都会转换为某种循环。 但是，您可以采取一些步骤来提高效率，它们在 PHP 5.5 和 5.3/5.4 中有所不同。

PHP 5.3/5.4 方式

执行此操作的最有效方法是将函数拆分为 2 个单独的步骤。 在第一步中，您将为电子邮件列表生成一个键映射。

$keys = array();
foreach($emails as $k => $email)
{
    $keys[$email->msgno] = $k;
}

在第二步中，您迭代多维 $threads 中的所有值并将它们替换为电子邮件详细信息：

// Iterate threads
$threads = array_map(function($thread) use($emails, $keys)
{
    // Iterate emails in these threads
    return array_map(function($msgno) use($emails, $keys)
    {
        // Swap the msgno with the email details
        return $emails[$keys[$msgno]];

    }, $thread);

}, $threads);

概念证明：http://pastebin.com/rp5QFN4J

匿名函数中关键字use的解释：

为了使用父作用域中定义的变量，可以使用use()关键字将变量从父作用域导入闭包作用域。虽然它是在 PHP 5.3 中引入的，但尚未在官方 PHP 手册中记录。 php 的 wiki 上只有一个草稿文档 https://wiki.php.net/rfc/closures#userland_perspective

PHP 5.5

此版本中的一项新功能使您能够使用生成器，其内存指纹明显更小，因此效率更高。

生成器中关键字yield的解释：

生成器函数的核心是 yield 关键字。在最简单的形式中，yield 语句看起来很像 return 语句，只是它不是停止函数的执行并返回，而是为在生成器上循环的代码提供一个值并暂停生成器函数的执行。

第一步：

function genetateKeyMap($emails)
{
    foreach($emails as $k => $email)
    {
        // Yielding key => value pair to result set
        yield $email->msgno => $k;
    }
};
$keys = iterator_to_array(genetateKeyMap($emails));

第二步：

function updateThreads($emails, $threads, $keys)
{
    foreach($threads as $thread)
    {
        $array = array();

        // Create a set of detailed emails
        foreach($thread as $msgno)
        {
            $array[] = $emails[$keys[$msgno]];
        }

        // Yielding array to result set
        yield $array;
    }
};
$threads = iterator_to_array(updateThreads($emails, $threads, $keys));

关于生成器返回的值的几句话：

生成器返回一个对象，它是 SPL 迭代器的一个实例，因此它需要使用 iterator_to_array() 才能将其转换为与您的代码所期望的完全相同的数组结构。您不需要这样做，但它需要在生成器函数之后更新您的代码，这可能会更有效。

概念证明：http://pastebin.com/9Z4pftBH

测试性能：

我生成了一个包含 7000 个线程的列表，每个线程包含 5 条消息，并测试了每种方法的性能（5 次测试的平均值）：

                   Takes:       Memory used:
                   ----------------------------
3x foreach():      2.8s              5.2 MB
PHP 5.3/5.4 way    0.061s            2.7 MB
PHP 5.5 way        0.036s            2.7 MB

虽然您的机器/服务器上的结果可能不同，但概述显示两步法比使用 3 个 foreach 循环快 45-77 倍

测试脚本：http://pastebin.com/M40hf0x7

Answer 4

带有分支的实现（比单个线程更复杂 array('5' => array(5,7,8))，但除非我只与一个人交谈，否则线程总是倾向于为我个人分支，所以我必须应对增加的复杂性）

<?php 
$threads = imap_thread($imap, SE_UID);
/*
 * threads returns entries as follows:
 * <id>.num = <messageid>
 * <id>.next = <messageid of first reply to <id>>,  0 = no replies
 * <id>.branch = <messageid of nth. reply to <parent of id>>, 0 = no more branches
 * Keep in mind: _every_ message 'starts' a branch, but that may be empty.
 */
$nodes = array( 0 => array( 'children' => array()));
$ids = array();
foreach ($threads as $key => $val) {
    list($treeid,$type) = explode('.',$key);
    switch($type){
        case 'num':
            //the actual message number of this tree node
            //store id for retrieval later:
            $ids[$val] = null;
            if($val==0){
                //return to root
                $nodes[$treeid] = &$nodes[0];
            } else {
                if(!isset($nodes[$treeid])) $nodes[$treeid] = array();
                $nodes[$treeid] = array_merge($nodes[$treeid],array(
                    'id' => $val,
                    'message' => &$ids[$val],
                    'treeid' => $treeid));
            }
            break;
        case 'next':
            // 0 means no next message, anything else is a reply
            if (0!=$val) {
                if(!isset($nodes[$val])) $nodes[$val] = array('parent' => $treeid);
                $nodes[$treeid][] = &$nodes[$val];
            }
            break;
        case 'branch':
            //0 means end of branch, a number means continue as sibling \
            //so we need to know the parent
            if (0!=$val) {
                if(!isset($nodes[$val])) $nodes[$val] = array('parent' => $nodes[$treeid]['parent']?:0);
                $nodes[$nodes[$val]['parent']][] = &$nodes[$val];
            }
            break;
        default:
            trigger_error("Unknown tree traverse-type: $type", E_USER_WARNING);
    }
}
//the great thing is we can get all our ID's at once:
$keystofetch = implode(',',array_filter(array_keys($nodes)));
$messages = imap_fetch_overview($imap,$keystofetch, FT_UID);
foreach($messages as $message){
    // you can of course store the _whole_ message in this thread like:
    // $nodes[$message->uid]['message'] = get_object_vars($message);
    // and do what you like with $tree[0]['children'] (be it a resursive array iterator,
    // or a  resursive function, your pick.
    // However, for this example we are going to only set message to a string of p.o.c 
    // (which is also nicer for our treeiterator)
    $ids[$message->uid] = $message->from.':'.$message->subject;
}
//let's show the result:
$it = new RecursiveTreeIterator(new RecursiveArrayIterator($nodes[0]),
    RecursiveTreeIterator::BYPASS_CURRENT,
    CachingIterator::TOSTRING_USE_KEY);
foreach($it as $key => $item){
    echo "$key".(is_scalar($item)?': '.$item:'').PHP_EOL;
}

这给了我们：

|-children
|-0
| |-parent: 0
| |-id: 35
| |-message: Friend Purple Acc2 <purple2@example.com>:A bigger message thread
| |-treeid: 1
| \-0
|   |-parent: 1
|   |-id: 7
|   |-message: Friend White <white@example.com>:Re: A bigger message thread
|   |-treeid: 2
|   \-0
|     |-parent: 2
|     |-id: 11
|     |-message: Friend Grey <grey@example.com>Re: A bigger message thread
|     |-treeid: 3
|     \-0
|       |-parent: 3
|       |-id: 39
|       |-message: Friend Purple Acc2 <purple2@example.com>:Re: A bigger message thread
|       |-treeid: 4
|       \-0
|         |-parent: 4
|         |-id: 40
|         |-message: Friend Pink <pink@example.com>:Re: A bigger message thread
|         |-treeid: 5
|         \-0
|           |-parent: 5
|           |-id: 38
|           |-message: Friend Yellow <yellow@example.com>:Re: A bigger message thread
|           |-treeid: 6
|           \-0
|             |-parent: 6
|             |-id: 12
|             |-message: Friend Pink <pink@example.com>:Re: A bigger message thread
|             |-treeid: 7
|             \-0
|               |-parent: 7
|               |-id: 25
|               |-message: Friend White <white@example.com>:Re: A bigger message thread
|               |-treeid: 8
|               \-0
|                 |-parent: 8
|                 |-id: 19
|                 |-message: Friend Black <black@example.com>:Re: A bigger message thread
|                 |-treeid: 9
|                 \-0
|                   |-parent: 9
|                   |-id: 23
|                   |-message: Friend Black <black@example.com>:Re: A bigger message thread
|                   |-treeid: 10
|                   \-0
|                     |-parent: 10
|                     |-id: 30
|                     |-message: Friend Yellow <yellow@example.com>:Re: A bigger message thread
|                     |-treeid: 11
|                     \-0
|                       |-parent: 11
|                       |-id: 2
|                       |-message: Friend Yellow <yellow@example.com>:Re: A bigger message thread
|                       |-treeid: 12
|                       |-0
|                       | |-parent: 12
|                       | |-id: 20
|                       | |-message: Me <me@example.com>:Re: A bigger message thread
|                       | |-treeid: 13
|                       | \-0
|                       |   |-parent: 13
|                       |   |-id: 1
|                       |   |-message: Fiend Silver <silver@example.com>:Re: A bigger message thread
|                       |   |-treeid: 14
|                       |   \-0
|                       |     |-parent: 14
|                       |     |-id: 41
|                       |     |-message: Fiend Silver <silver@example.com>:Re: A bigger message thread
|                       |     |-treeid: 15
|                       |     \-0
|                       |       |-parent: 15
|                       |       |-id: 27
|                       |       |-message: Friend Grey <grey@example.com>Re: A bigger message thread
|                       |       |-treeid: 16
|                       |       \-0
|                       |         |-parent: 16
|                       |         |-id: 17
|                       |         |-message: Friend Magenta <magenta@example.com>:Re: A bigger message thread
|                       |         |-treeid: 17
|                       |         |-0
|                       |         | |-parent: 17
|                       |         | |-id: 31
|                       |         | |-message: Friend Purple <purple@example.com>:Re: A bigger message thread
|                       |         | |-treeid: 18
|                       |         | \-0
|                       |         |   |-parent: 18
|                       |         |   |-id: 4
|                       |         |   |-message: Friend Black <black@example.com>:Re: A bigger message thread
|                       |         |   |-treeid: 19
|                       |         |   \-0
|                       |         |     |-parent: 19
|                       |         |     |-id: 37
|                       |         |     |-message: Friend Black <black@example.com>:Re: A bigger message thread
|                       |         |     |-treeid: 20
|                       |         |     \-0
|                       |         |       |-parent: 20
|                       |         |       |-id: 24
|                       |         |       |-message: Friend Purple Acc2 <purple2@example.com>:Re: A bigger message thread
|                       |         |       |-treeid: 21
|                       |         |       \-0
|                       |         |         |-parent: 21
|                       |         |         |-id: 13
|                       |         |         |-message: Friend White <white@example.com>:Re: A bigger message thread
|                       |         |         \-treeid: 22
|                       |         \-1
|                       |           |-parent: 17
|                       |           |-id: 15
|                       |           |-message: Friend Grey <grey@example.com>Re: A bigger message thread
|                       |           |-treeid: 23
|                       |           \-0
|                       |             |-parent: 23
|                       |             |-id: 18
|                       |             |-message: Friend Magenta <magenta@example.com>:Re: A bigger message thread
|                       |             |-treeid: 24
|                       |             \-0
|                       |               |-parent: 24
|                       |               |-id: 45
|                       |               |-message: Friend Black <black@example.com>:Re: A bigger message thread
|                       |               \-treeid: 25
|                       \-1
|                         |-parent: 12
|                         |-id: 46
|                         |-message: Friend Yellow <yellow@example.com>:Re: A bigger message thread
|                         |-treeid: 26
|                         \-0
|                           |-parent: 26
|                           |-id: 29
|                           |-message: Fiend Silver <silver@example.com>:Re: A bigger message thread
|                           |-treeid: 27
|                           \-0
|                             |-parent: 27
|                             |-id: 26
|                             |-message: Friend Magenta <magenta@example.com>:Re: A bigger message thread
|                             |-treeid: 28
|                             |-0
|                             | |-parent: 28
|                             | |-id: 34
|                             | |-message: Friend Grey <grey@example.com>Re: A bigger message thread
|                             | \-treeid: 29
|                             |-1
|                             | |-parent: 28
|                             | |-id: 33
|                             | |-message: Friend Yellow <yellow@example.com>:Re: A bigger message thread
|                             | |-treeid: 30
|                             | \-0
|                             |   |-parent: 30
|                             |   |-id: 36
|                             |   |-message: Friend White <white@example.com>:Re: A bigger message thread
|                             |   |-treeid: 31
|                             |   |-0
|                             |   | |-parent: 31
|                             |   | |-id: 10
|                             |   | |-message: Friend White <white@example.com>:Re: A bigger message thread
|                             |   | \-treeid: 32
|                             |   \-1
|                             |     |-parent: 31
|                             |     |-id: 48
|                             |     |-message: Friend Pink <pink@example.com>:Re: A bigger message thread
|                             |     \-treeid: 33
|                             \-2
|                               |-parent: 28
|                               |-id: 47
|                               |-message: Friend Purple <purple@example.com>:Re: A bigger message thread
|                               |-treeid: 34
|                               \-0
|                                 |-parent: 34
|                                 |-id: 5
|                                 |-message: Friend White <white@example.com>:Re: A bigger message thread
|                                 |-treeid: 35
|                                 \-0
|                                   |-parent: 35
|                                   |-id: 3
|                                   |-message: Friend Purple <purple@example.com>:Re: A bigger message thread
|                                   |-treeid: 36
|                                   \-0
|                                     |-parent: 36
|                                     |-id: 21
|                                     |-message: Friend Yellow <yellow@example.com>:Re: A bigger message thread
|                                     |-treeid: 37
|                                     \-0
|                                       |-parent: 37
|                                       |-id: 8
|                                       |-message: Friend Purple <purple@example.com>:Re: A bigger message thread
|                                       |-treeid: 38
|                                       \-0
|                                         |-parent: 38
|                                         |-id: 43
|                                         |-message: Friend White <white@example.com>:Re: A bigger message thread
|                                         |-treeid: 39
|                                         \-0
|                                           |-parent: 39
|                                           |-id: 28
|                                           |-message: Friend Purple <purple@example.com>:Re: A bigger message thread
|                                           |-treeid: 40
|                                           \-0
|                                             |-parent: 40
|                                             |-id: 42
|                                             |-message: Friend Brown <brown@example.com>:Re: A bigger message thread
|                                             |-treeid: 41
|                                             \-0
|                                               |-parent: 41
|                                               |-id: 22
|                                               |-message: Friend Purple <purple@example.com>:Re: A bigger message thread
|                                               \-treeid: 42
|-1
| |-parent: 0
| |-id: 9
| |-message: Friend Blue <blue@example.com>:RE: A bigger message thread
| \-treeid: 43
|-2
| \-parent: 0
|-3
| |-parent: 44
| |-id: 49
| |-message: Some Subcription <foo@example.com>:Newsletter #1
| \-treeid: 45
|-4
| |-parent: 44
| |-id: 50
| |-message: Some Subcription <foo@example.com>:Newsletter #2
| \-treeid: 46
\-5
  |-parent: 0
  |-id: 32
  |-message: Friend Red <red@example.com>:A second mainthread
  |-treeid: 47
  \-0
    |-parent: 47
    |-id: 16
    |-message: Friend Black <black@example.com>:Re: A second mainthread
    |-treeid: 48
    \-0
      |-parent: 48
      |-id: 14
      |-message: Friend Red <red@example.com>:Re: A second mainthread
      |-treeid: 49
      \-0
        |-parent: 49
        |-id: 6
        |-message: Friend White <white@example.com>:Re: A second mainthread
        |-treeid: 50
        \-0
          |-parent: 50
          |-id: 44
          |-message: Fiend Silver <silver@example.com>:Re: A second mainthread
          \-treeid: 51

注意几点：

• 此脚本的第一个版本错误地将分支添加到 节点的第一个子节点而不是实际节点本身，即 现在通过存储其父级来修复。
• imap_thread 并不完美：我们将id=9 视为孤儿，尽管它似乎应该在某个地方的第一个线程中。然而，由于 标题没有提到这一点，谷歌应用程序在这里决定让它 它是自己的节点。
• 第三个（key=2）条目是一种“返回根”的方法，因为N.num.N.branch,N.next 方法显然没有其他返回方法 扎根。这是/return to root $nodes[$treeid] = &$nodes[0]; 少量。在确定所有其他之后，您可以/应该将其过滤掉 节点，但首先需要它来构建数组。

仅获取启动新线程的节点（第 N 个消息回复，N>1）：

$threads = imap_thread($imap, SE_UID);
$branchestarts = array();
foreach($threads as $key => $value){
    list($num,$type) = explode('.',$key);
    if (
        $type=='num'                     // an id
        && $value == 0                   // which is actually root
        && isset($threads[$num.'.next']) // then check for next
        && isset($threads[$threads[$num.'.next'].'.num'])
    ){
        $branchestarts[] = $threads[$threads[$num.'.next'].'.num'];
    } else if(
        $type=='branch'                   // branch movement
        && $value != 0                    // not back
        && isset($threads[$value.'.num']) // sanity: target exists
        && $threads[$value.'.num'] != 0   // and is not a return to root
    ){
        $branchestarts[] = $threads[$value.'.num'];
    }
}
echo json_encode($branchestarts);

这给了我们：

[35,15,46,33,48,47,9,49,50,32]

确实，35、49、50 和 32 是线程的开始，9 也被 imap 服务器识别为这样，其余的是第二个或更多回复开始他们自己的分支。

现在，您可以确实将分支拆分为单独的对话，但正如您所见，这些通常只有 1 或 2 个回复，较长的线程往往会很少发展。 要查看这些“分支”的运行情况：

$branches = array();
$currenttree = null;
foreach($threads as $key => $value){
    list($num,$type) = explode('.',$key);
    switch($type){
        case 'num':
            //nothing
            break;
        case 'next':
            if(is_null($currenttree)) $currenttree = &$branches[$threads[$value.'.num']];
            if($value && isset($threads[$value.'.num'])) $currenttree[] = $threads[$value.'.num'];
            break;
        case 'branch':
            unset($currenttree);
            if($value && $threads[$value.'.num']){
                $branches[$threads[$value.'.num']] = array($threads[$value.'.num']);
                $currenttree =& $branches[$threads[$value.'.num']];
            }
    }
}
echo json_encode($branches, JSON_PRETTY_PRINT);

这为您提供了根源和分支及其回复：

{
    "35": [
        35,
        7,
        11,
        39,
        40,
        38,
        12,
        25,
        19,
        23,
        30,
        2,
        20,
        1,
        41,
        27,
        17,
        31,
        4,
        37,
        24,
        13
    ],
    "15": [
        15,
        18,
        45
    ],
    "46": [
        46,
        29,
        26,
        34
    ],
    "33": [
        33,
        36,
        10
    ],
    "48": [
        48
    ],
    "47": [
        47,
        5,
        3,
        21,
        8,
        43,
        28,
        42,
        22
    ],
    "9": [
        9
    ],
    "49": [
        49
    ],
    "50": [
        50
    ],
    "32": [
        32,
        16,
        14,
        6,
        44
    ]
}

稍作改动，我们就可以在其中获取消息：

$branches = array();
$currenttree = null;
$messages = array();
foreach($threads as $key => $value){
    list($num,$type) = explode('.',$key);
    switch($type){
        case 'num':
            //nothing
            break;
        case 'next':
            if(is_null($currenttree)) $currenttree = &$branches[$threads[$value.'.num']];
            if($value && isset($threads[$value.'.num'])) $currenttree[] = &$messages[$threads[$value.'.num']];
            break;
        case 'branch':
            unset($currenttree);
            if($value && $threads[$value.'.num']){
                $branches[$threads[$value.'.num']] = array(&$messages[$threads[$value.'.num']]);
                $currenttree =& $branches[$threads[$value.'.num']];
            } else {
                $currenttree = null;
            }
    }
}
$keystofetch = implode(',',array_filter(array_keys($messages)));
foreach(imap_fetch_overview($imap,$keystofetch,FT_UID) as $message){
        $messages[$message->uid] = $message;
}
echo json_encode($branches);//won't show it's output, this answer is to large as it is ;)

另一种选择是仅按日期时间值对它们进行排序，这对于分支很少/可忽略不计的对话是可以的，这可能会使您计划的大部分代码都能正常工作。

两者的结合将是“移动分支”，依次跟随线程，因此：

 1       2013-06-01
   2     2013-06-02
     3   2013-06-03
   4     2013-06-03
     5   2013-06-04

变成1,2,3,4,5 的序列，但3 上的回复会使用它：

 1       2013-06-01
   4     2013-06-03
     5   2013-06-04
   2     2013-06-02
     3   2013-06-03
       6 2013-06-05

使其成为1,4,5,2,3,6 的序列，这将使其保持逻辑流畅的对话，始终将最后一个回复的线程/分支作为最后一个。