我需要在平面文件中存储多维数据关联数组，以便进行缓存。我可能偶尔会遇到需要将其转换为JSON以在我的web应用程序中使用，但绝大多数情况下，我将直接在PHP中使用数组。
在这个文本文件中将数组存储为JSON还是PHP序列化数组更有效?我查看了一下，似乎在最新版本的PHP(5.3)中，json_decode实际上比反序列化更快。
我目前倾向于将数组存储为JSON，因为我觉得如果有必要的话，它更容易被人阅读，它可以在PHP和JavaScript中使用，而且从我所读到的，它甚至可能更快地解码(虽然不确定编码)。
有人知道有什么陷阱吗?有人有好的基准来显示这两种方法的性能优势吗?
当前回答
我知道这有点晚了，但答案很旧，我想我的基准测试可能会有帮助，因为我刚刚在PHP 7.4中测试过
Serialize/Unserialize比JSON快得多，占用的内存和空间更少，在PHP 7.4中完全胜出，但我不确定我的测试是最有效或最好的。
我基本上创建了一个PHP文件，它返回一个数组，我编码，序列化，然后解码和反序列化。
$array = include __DIR__.'/../tests/data/dao/testfiles/testArray.php';
//JSON ENCODE
$json_encode_memory_start = memory_get_usage();
$json_encode_time_start = microtime(true);
for ($i=0; $i < 20000; $i++) {
$encoded = json_encode($array);
}
$json_encode_time_end = microtime(true);
$json_encode_memory_end = memory_get_usage();
$json_encode_time = $json_encode_time_end - $json_encode_time_start;
$json_encode_memory =
$json_encode_memory_end - $json_encode_memory_start;
//SERIALIZE
$serialize_memory_start = memory_get_usage();
$serialize_time_start = microtime(true);
for ($i=0; $i < 20000; $i++) {
$serialized = serialize($array);
}
$serialize_time_end = microtime(true);
$serialize_memory_end = memory_get_usage();
$serialize_time = $serialize_time_end - $serialize_time_start;
$serialize_memory = $serialize_memory_end - $serialize_memory_start;
//Write to file time:
$fpc_memory_start = memory_get_usage();
$fpc_time_start = microtime(true);
for ($i=0; $i < 20000; $i++) {
$fpc_bytes =
file_put_contents(
__DIR__.'/../tests/data/dao/testOneBigFile',
'<?php return '.var_export($array,true).' ?>;'
);
}
$fpc_time_end = microtime(true);
$fpc_memory_end = memory_get_usage();
$fpc_time = $fpc_time_end - $fpc_time_start;
$fpc_memory = $fpc_memory_end - $fpc_memory_start;
//JSON DECODE
$json_decode_memory_start = memory_get_usage();
$json_decode_time_start = microtime(true);
for ($i=0; $i < 20000; $i++) {
$decoded = json_encode($encoded);
}
$json_decode_time_end = microtime(true);
$json_decode_memory_end = memory_get_usage();
$json_decode_time = $json_decode_time_end - $json_decode_time_start;
$json_decode_memory =
$json_decode_memory_end - $json_decode_memory_start;
//UNSERIALIZE
$unserialize_memory_start = memory_get_usage();
$unserialize_time_start = microtime(true);
for ($i=0; $i < 20000; $i++) {
$unserialized = unserialize($serialized);
}
$unserialize_time_end = microtime(true);
$unserialize_memory_end = memory_get_usage();
$unserialize_time = $unserialize_time_end - $unserialize_time_start;
$unserialize_memory =
$unserialize_memory_end - $unserialize_memory_start;
//GET FROM VAR EXPORT:
$var_export_memory_start = memory_get_usage();
$var_export_time_start = microtime(true);
for ($i=0; $i < 20000; $i++) {
$array = include __DIR__.'/../tests/data/dao/testOneBigFile';
}
$var_export_time_end = microtime(true);
$var_export_memory_end = memory_get_usage();
$var_export_time = $var_export_time_end - $var_export_time_start;
$var_export_memory = $var_export_memory_end - $var_export_memory_start;
结果:
Var输出长度:11447 序列化长度:11541 Json编码长度:11895 文件放内容字节:11464
Json编码时间:1.9197590351105 序列化时间:0.160325050354 FPC时间:6.2793469429016
Json编码内存:12288 序列化内存:12288 FPC内存:0
JSON解码时间:1.7493588924408 UnSerialize Time: 0.19309520721436 Var导出和包括:3.1974139213562
JSON解码内存:16384 反序列化内存:14360 Var Export and Include: 192
其他回答
我已经在一个相当复杂、嵌套简单、包含各种数据(字符串、NULL、整数)的多散列上对此进行了非常彻底的测试，序列化/反序列化最终比json_encode/json_decode快得多。
在我的测试中，json的唯一优势是它的“打包”大小更小。
这些都是在PHP 5.3.3下完成的，如果你想了解更多细节，请告诉我。
下面是测试结果，然后是生成它们的代码。我不能提供测试数据，因为它会泄露一些我不能公开的信息。
JSON encoded in 2.23700618744 seconds
PHP serialized in 1.3434419632 seconds
JSON decoded in 4.0405561924 seconds
PHP unserialized in 1.39393305779 seconds
serialized size : 14549
json_encode size : 11520
serialize() was roughly 66.51% faster than json_encode()
unserialize() was roughly 189.87% faster than json_decode()
json_encode() string was roughly 26.29% smaller than serialize()
// Time json encoding
$start = microtime( true );
for($i = 0; $i < 10000; $i++) {
json_encode( $test );
}
$jsonTime = microtime( true ) - $start;
echo "JSON encoded in $jsonTime seconds<br>";
// Time serialization
$start = microtime( true );
for($i = 0; $i < 10000; $i++) {
serialize( $test );
}
$serializeTime = microtime( true ) - $start;
echo "PHP serialized in $serializeTime seconds<br>";
// Time json decoding
$test2 = json_encode( $test );
$start = microtime( true );
for($i = 0; $i < 10000; $i++) {
json_decode( $test2 );
}
$jsonDecodeTime = microtime( true ) - $start;
echo "JSON decoded in $jsonDecodeTime seconds<br>";
// Time deserialization
$test2 = serialize( $test );
$start = microtime( true );
for($i = 0; $i < 10000; $i++) {
unserialize( $test2 );
}
$unserializeTime = microtime( true ) - $start;
echo "PHP unserialized in $unserializeTime seconds<br>";
$jsonSize = strlen(json_encode( $test ));
$phpSize = strlen(serialize( $test ));
echo "<p>serialized size : " . strlen(serialize( $test )) . "<br>";
echo "json_encode size : " . strlen(json_encode( $test )) . "<br></p>";
// Compare them
if ( $jsonTime < $serializeTime )
{
echo "json_encode() was roughly " . number_format( ($serializeTime / $jsonTime - 1 ) * 100, 2 ) . "% faster than serialize()";
}
else if ( $serializeTime < $jsonTime )
{
echo "serialize() was roughly " . number_format( ($jsonTime / $serializeTime - 1 ) * 100, 2 ) . "% faster than json_encode()";
} else {
echo 'Unpossible!';
}
echo '<BR>';
// Compare them
if ( $jsonDecodeTime < $unserializeTime )
{
echo "json_decode() was roughly " . number_format( ($unserializeTime / $jsonDecodeTime - 1 ) * 100, 2 ) . "% faster than unserialize()";
}
else if ( $unserializeTime < $jsonDecodeTime )
{
echo "unserialize() was roughly " . number_format( ($jsonDecodeTime / $unserializeTime - 1 ) * 100, 2 ) . "% faster than json_decode()";
} else {
echo 'Unpossible!';
}
echo '<BR>';
// Compare them
if ( $jsonSize < $phpSize )
{
echo "json_encode() string was roughly " . number_format( ($phpSize / $jsonSize - 1 ) * 100, 2 ) . "% smaller than serialize()";
}
else if ( $phpSize < $jsonSize )
{
echo "serialize() string was roughly " . number_format( ($jsonSize / $phpSize - 1 ) * 100, 2 ) . "% smaller than json_encode()";
} else {
echo 'Unpossible!';
}
我对测试进行了扩展，以包括反序列化性能。这是我得到的数字。
Serialize
JSON encoded in 2.5738489627838 seconds
PHP serialized in 5.2861361503601 seconds
Serialize: json_encode() was roughly 105.38% faster than serialize()
Unserialize
JSON decode in 10.915472984314 seconds
PHP unserialized in 7.6223039627075 seconds
Unserialize: unserialize() was roughly 43.20% faster than json_decode()
因此json似乎编码更快，但解码较慢。因此，这可能取决于您的应用程序以及您希望最大限度地实现什么。
似乎serialize是我要使用的一个，有两个原因:
有人指出，unserialize比json_decode更快，而且'read' case听起来比'write' case更有可能。 当使用无效UTF-8字符的字符串时，我遇到了json_encode的问题。当这种情况发生时，字符串最终为空，导致信息丢失。
我知道这有点晚了，但答案很旧，我想我的基准测试可能会有帮助，因为我刚刚在PHP 7.4中测试过
Serialize/Unserialize比JSON快得多，占用的内存和空间更少，在PHP 7.4中完全胜出，但我不确定我的测试是最有效或最好的。
我基本上创建了一个PHP文件，它返回一个数组，我编码，序列化，然后解码和反序列化。
$array = include __DIR__.'/../tests/data/dao/testfiles/testArray.php';
//JSON ENCODE
$json_encode_memory_start = memory_get_usage();
$json_encode_time_start = microtime(true);
for ($i=0; $i < 20000; $i++) {
$encoded = json_encode($array);
}
$json_encode_time_end = microtime(true);
$json_encode_memory_end = memory_get_usage();
$json_encode_time = $json_encode_time_end - $json_encode_time_start;
$json_encode_memory =
$json_encode_memory_end - $json_encode_memory_start;
//SERIALIZE
$serialize_memory_start = memory_get_usage();
$serialize_time_start = microtime(true);
for ($i=0; $i < 20000; $i++) {
$serialized = serialize($array);
}
$serialize_time_end = microtime(true);
$serialize_memory_end = memory_get_usage();
$serialize_time = $serialize_time_end - $serialize_time_start;
$serialize_memory = $serialize_memory_end - $serialize_memory_start;
//Write to file time:
$fpc_memory_start = memory_get_usage();
$fpc_time_start = microtime(true);
for ($i=0; $i < 20000; $i++) {
$fpc_bytes =
file_put_contents(
__DIR__.'/../tests/data/dao/testOneBigFile',
'<?php return '.var_export($array,true).' ?>;'
);
}
$fpc_time_end = microtime(true);
$fpc_memory_end = memory_get_usage();
$fpc_time = $fpc_time_end - $fpc_time_start;
$fpc_memory = $fpc_memory_end - $fpc_memory_start;
//JSON DECODE
$json_decode_memory_start = memory_get_usage();
$json_decode_time_start = microtime(true);
for ($i=0; $i < 20000; $i++) {
$decoded = json_encode($encoded);
}
$json_decode_time_end = microtime(true);
$json_decode_memory_end = memory_get_usage();
$json_decode_time = $json_decode_time_end - $json_decode_time_start;
$json_decode_memory =
$json_decode_memory_end - $json_decode_memory_start;
//UNSERIALIZE
$unserialize_memory_start = memory_get_usage();
$unserialize_time_start = microtime(true);
for ($i=0; $i < 20000; $i++) {
$unserialized = unserialize($serialized);
}
$unserialize_time_end = microtime(true);
$unserialize_memory_end = memory_get_usage();
$unserialize_time = $unserialize_time_end - $unserialize_time_start;
$unserialize_memory =
$unserialize_memory_end - $unserialize_memory_start;
//GET FROM VAR EXPORT:
$var_export_memory_start = memory_get_usage();
$var_export_time_start = microtime(true);
for ($i=0; $i < 20000; $i++) {
$array = include __DIR__.'/../tests/data/dao/testOneBigFile';
}
$var_export_time_end = microtime(true);
$var_export_memory_end = memory_get_usage();
$var_export_time = $var_export_time_end - $var_export_time_start;
$var_export_memory = $var_export_memory_end - $var_export_memory_start;
结果:
Var输出长度:11447 序列化长度:11541 Json编码长度:11895 文件放内容字节:11464
Json编码时间:1.9197590351105 序列化时间:0.160325050354 FPC时间:6.2793469429016
Json编码内存:12288 序列化内存:12288 FPC内存:0
JSON解码时间:1.7493588924408 UnSerialize Time: 0.19309520721436 Var导出和包括:3.1974139213562
JSON解码内存:16384 反序列化内存:14360 Var Export and Include: 192
看看这里的结果(很抱歉把PHP代码放在JS代码框中):
http://jsfiddle.net/newms87/h3b0a0ha/embedded/result/
结果:serialize()和unserialize()在PHP 5.4中对于不同大小的数组都要快得多。
我在真实世界的数据上做了一个测试脚本，比较json_encode vs serialize和json_decode vs unserialize。测试是在一个生产中的电子商务网站的缓存系统上运行的。它只是获取缓存中已经存在的数据，并测试编码/解码(或序列化/反序列化)所有数据的时间，然后我将其放入一个易于查看的表中。
我在PHP 5.4共享托管服务器上运行了这个程序。
结果是非常结论性的，对于这些大到小的数据集，序列化和非序列化是明显的赢家。特别是对于我的用例，json_decode和unserialize对于缓存系统是最重要的。在这里，Unserialize几乎是一个无处不在的赢家。它的速度通常是json_decode的2到4倍(有时是6或7倍)。
有趣的是，@peter-bailey的结果有所不同。
下面是用于生成结果的PHP代码:
<?php
ini_set('display_errors', 1);
error_reporting(E_ALL);
function _count_depth($array)
{
$count = 0;
$max_depth = 0;
foreach ($array as $a) {
if (is_array($a)) {
list($cnt, $depth) = _count_depth($a);
$count += $cnt;
$max_depth = max($max_depth, $depth);
} else {
$count++;
}
}
return array(
$count,
$max_depth + 1,
);
}
function run_test($file)
{
$memory = memory_get_usage();
$test_array = unserialize(file_get_contents($file));
$memory = round((memory_get_usage() - $memory) / 1024, 2);
if (empty($test_array) || !is_array($test_array)) {
return;
}
list($count, $depth) = _count_depth($test_array);
//JSON encode test
$start = microtime(true);
$json_encoded = json_encode($test_array);
$json_encode_time = microtime(true) - $start;
//JSON decode test
$start = microtime(true);
json_decode($json_encoded);
$json_decode_time = microtime(true) - $start;
//serialize test
$start = microtime(true);
$serialized = serialize($test_array);
$serialize_time = microtime(true) - $start;
//unserialize test
$start = microtime(true);
unserialize($serialized);
$unserialize_time = microtime(true) - $start;
return array(
'Name' => basename($file),
'json_encode() Time (s)' => $json_encode_time,
'json_decode() Time (s)' => $json_decode_time,
'serialize() Time (s)' => $serialize_time,
'unserialize() Time (s)' => $unserialize_time,
'Elements' => $count,
'Memory (KB)' => $memory,
'Max Depth' => $depth,
'json_encode() Win' => ($json_encode_time > 0 && $json_encode_time < $serialize_time) ? number_format(($serialize_time / $json_encode_time - 1) * 100, 2) : '',
'serialize() Win' => ($serialize_time > 0 && $serialize_time < $json_encode_time) ? number_format(($json_encode_time / $serialize_time - 1) * 100, 2) : '',
'json_decode() Win' => ($json_decode_time > 0 && $json_decode_time < $serialize_time) ? number_format(($serialize_time / $json_decode_time - 1) * 100, 2) : '',
'unserialize() Win' => ($unserialize_time > 0 && $unserialize_time < $json_decode_time) ? number_format(($json_decode_time / $unserialize_time - 1) * 100, 2) : '',
);
}
$files = glob(dirname(__FILE__) . '/system/cache/*');
$data = array();
foreach ($files as $file) {
if (is_file($file)) {
$result = run_test($file);
if ($result) {
$data[] = $result;
}
}
}
uasort($data, function ($a, $b) {
return $a['Memory (KB)'] < $b['Memory (KB)'];
});
$fields = array_keys($data[0]);
?>
<table>
<thead>
<tr>
<?php foreach ($fields as $f) { ?>
<td style="text-align: center; border:1px solid black;padding: 4px 8px;font-weight:bold;font-size:1.1em"><?= $f; ?></td>
<?php } ?>
</tr>
</thead>
<tbody>
<?php foreach ($data as $d) { ?>
<tr>
<?php foreach ($d as $key => $value) { ?>
<?php $is_win = strpos($key, 'Win'); ?>
<?php $color = ($is_win && $value) ? 'color: green;font-weight:bold;' : ''; ?>
<td style="text-align: center; vertical-align: middle; padding: 3px 6px; border: 1px solid gray; <?= $color; ?>"><?= $value . (($is_win && $value) ? '%' : ''); ?></td>
<?php } ?>
</tr>
<?php } ?>
</tbody>
</table>
