robust way to traverse an array - php

Question

I had the data in XML file i.e.
<domain>
<host>xyz</host>
<key>keeeeeeeeeey</key>
</domain>
<domain>
<host>xyz</host>
<key>keeeeeeeeeey</key>
</domain>
From that xml I created an array for robustness had I knew how to find that using xml I would have done so but lack of my knowledge I converted that xml file into array using:
$json = json_encode($xml);
$array = json_decode($json,TRUE);`
Below is my array:
Array
(
[domain] => Array
(
[0] => Array
(
[host] => bdbdfbdvbdbdfbdfbf.net
[key] => 933f416350de1a955544b30b5bb7ca09cfa2311101a22972320cc4c7af2ecedc03f36b8a48961ef938972478592a1e261819052b51c09a45cf805663f83cb2c0233969255a2c3e2e7e212a295a247b785d41
)
[1] => Array
(
[host] => bdev1vvvvvvveinf.net
[key] => 933f416350de1a955544b30b5bb7ca09cfa2311101a22972320cc4c7af2ecedc03f36b8a48961ef938972478592a1e261819052b51c09a45cf805663f83cb2c0233969255a2c3e2e7e212a295a247b785d41
)
[2] => Array
(
[host] => bdev1.aaaaaaaaureinf.net
[key] => 933f416350de1a955544b30b5bb7ca09cfa2311101a22972320cc4c7af2ecedc03f36b8a48961ef938972478592a1e261819052b51c09a45cf805663f83cb2c0233969255a2c3e2e7e212a295a247b785d41
)
[3] => Array
(
[host] => bdennnnnnnninf.net
[key] => 933f416350de1a955544b30b5bb7ca09cfa2311101a22972320cc4c7af2ecedc03f36b8a48961ef938972478592a1e261819052b51c09a45cf805663f83cb2c0233969255a2c3e2e7e212a295a247b785d41
)
[4] => Array
(
[host] => bdeveewerwerwerwerreinf.net
[key] => 933f416350de1a955544b30b5bb7ca09cfa2311101a22972320cc4c7af2ecedc03f36b8a48961ef938972478592a1e261819052b51c09a45cf805663f83cb2c0233969255a2c3e2e7e212a295a247b785d41
)
)
)
I want a robust loop through which if I pass the host name it returns the key. Can anyone please throw some light? The size of the array could grow to 100 000 000 plus entries.

Answer 1

Change your array to look like:
$data = array('domain' => array(
'bdbdfbdvbdbdfbdfbf.net' => '933...',
'bdev1vvvvvvveinf.net' => '933...',
));
Then you can do this:
echo $data['domain']['bdbdfbdvbdbdfbdfbf.net'];
There is no "robust" way to do it with your current array. You'd have to search through the entire thing:
function get_key($data, $host)
{
foreach ($data['domain'] as $domain)
{
if ($domain['host'] == $host)
return $domain['key'];
}
}
Given this new information:
The size of the array could grow to 100 000 000 plus entries.
I retract the usefulness of this answer, as the entire concept of using any plain text format, including XML or a serialized PHP key-value array, to store this amount of data is just crazy.
You should store the data in a database with the domain indexed. Even an sqlite database would be a major upgrade from a linear probe of a text file.
Of course there are ways to store the data in a custom format that is optimized, but there's really no good reason to reinvent something a database can easily do.

Answer 2

If possible, I think it would be better if host could be in place of the array key instead of a numeric index. That means it could look like
Array
(
[domain] => Array
(
[bdbdfbdvbdbdfbdfbf.net] => Array
(
[key] => 933f416350de1a955544b30b5bb7ca09cfa2311101a22972320cc4c7af2ecedc03f36b8a48961ef938972478592a1e261819052b51c09a45cf805663f83cb2c0233969255a2c3e2e7e212a295a247b785d41
)
[bdev1vvvvvvveinf.net] => Array
(
[key] => 933f416350de1a955544b30b5bb7ca09cfa2311101a22972320cc4c7af2ecedc03f36b8a48961ef938972478592a1e261819052b51c09a45cf805663f83cb2c0233969255a2c3e2e7e212a295a247b785d41
)
[bdev1.aaaaaaaaureinf.net] => Array
(
[key] => 933f416350de1a955544b30b5bb7ca09cfa2311101a22972320cc4c7af2ecedc03f36b8a48961ef938972478592a1e261819052b51c09a45cf805663f83cb2c0233969255a2c3e2e7e212a295a247b785d41
)
)
)
which would be searchable with
$somedomain = "bdev1.aaaaaaaaureinf.net";
if (isset($domains['domain'][$somedomain])) {
// do stuff
//$domains['domain'][$somedomain]['key']; is the key you want
}
If you can, do it that way

Answer 3

Since you only need the [domain] array from the outer array, this should work
function getKey($domains)
{
foreach($domains as $domain)
{
if($domain['host'] == $testHost)
return $domain['key'];
}
return false;
}
$myKey = getKey($myArr['domain']);

Answer 4

Here is a method that works with the array that you gave. You don't have to make any changes to the array.
/**
* Find the Key of the Domain in the Array with a Given Host
* #param $given The host you want to search for
* #returns The key of the domain (of the array) that has the matching host
*/
function findHost($given)
{
// This code assumes that the data array is $array .
global $array;
foreach ($array["domain"] as $key => $value)
{
if ($value["host"] == $given)
return $key;
}
// If no matches
return false;
}
// Call findHost() as you desire.
// If there is no match, the function returns false.
// Otherwise, it returns the key of $array["domain"] that the host matches.

Answer 5

With 100 000 000 plus entries you're likely hitting the string length limit in PHP which would mean that you can't use json_encode and json_decode any longer.
This does something similar, but you need to metric yourself what's faster:
$array = (array) $xml;
array_walk_recursive($array, function(&$v) { $v = (array) $v; });
Good luck!
Anyway, I wonder how large that XML string is then. Hmm. I think the numbers you give are just not right, your question looks pretty bogus on a second thought.