How to obtain remote image information efficiently in php?-PHP Tutorial-php.cn

How to obtain remote image information efficiently in php?

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Release： 2016-07-06 13:52:49

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<code><?php

set_time_limit(0);
$imageArray = [
        'http://ww2.sinaimg.cn/mw690/63918611gw1f51fiawmcrj208s0aeq4a.jpg',
        'http://ww3.sinaimg.cn/large/797a354agw1f4ya2a91tqj20k00zk765.jpg',
        'https://ss0.bdstatic.com/5aV1bjqh_Q23odCf/static/superman/img/logo/bd_logo1_31bdc765.png',
        'https://pic1.zhimg.com/d32d2194fac9dec7215e5581ca0fdc24_r.jpg',
    ];
echo date('Y-m-d H:i:s') . substr((string) microtime(), 1, 6), "\r\n";
foreach ($imageArray as $imageUrl) {
    $imageSize[] = @getimagesize($imageUrl);
    echo date('Y-m-d H:i:s') . substr((string) microtime(), 1, 6), "\r\n";
}
var_dump($imageSize);
</code>

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As follows, I have a page that wants to display image information, but getimagesize takes too long. Is there any other efficient method?
I am getting image information, not checking whether it exists

Reply content:

<code><?php

set_time_limit(0);
$imageArray = [
        'http://ww2.sinaimg.cn/mw690/63918611gw1f51fiawmcrj208s0aeq4a.jpg',
        'http://ww3.sinaimg.cn/large/797a354agw1f4ya2a91tqj20k00zk765.jpg',
        'https://ss0.bdstatic.com/5aV1bjqh_Q23odCf/static/superman/img/logo/bd_logo1_31bdc765.png',
        'https://pic1.zhimg.com/d32d2194fac9dec7215e5581ca0fdc24_r.jpg',
    ];
echo date('Y-m-d H:i:s') . substr((string) microtime(), 1, 6), "\r\n";
foreach ($imageArray as $imageUrl) {
    $imageSize[] = @getimagesize($imageUrl);
    echo date('Y-m-d H:i:s') . substr((string) microtime(), 1, 6), "\r\n";
}
var_dump($imageSize);
</code>

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As follows, I have a page that wants to display image information, but getimagesize takes too long. Is there any other efficient method?
I am getting image information, not checking whether it exists

The problem is this. This is definitely a pitfall for PHP.
The traffic is increasing, the image source site is unstable, there is a network problem, and the server is killed in minutes.

You can ask the front-end master if he has any plans or compromises.

If not, you can create a table in the database and maintain a copy of image information data.

Then when a picture is added, it is first judged whether the table has data. If the size information of the picture is not obtained and stored in the table, then the subsequent operations are performed.

Check it out directly when the page is displayed.

I won’t talk about caching, queuing, or image localization here (instead of using images from other sites), because it seems that these will greatly increase the complexity. We will consider it when necessary.

Isn’t there a master on the V2 site who has already proposed a solution?
http://v2ex.com/t/286977#reply17

try getImageInfo
getimagesize takes too long, maybe because your bandwidth is too low, or the image server responds slowly

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getimagesize

As noted below, getimagesize will download the entire image before it checks for the requested information. This is extremely slow on large images that are accessed remotely. Since the width/height is in the first few bytes of the file, there is no need to download the entire file. I wrote a function to get the size of a JPEG by streaming bytes until the proper data is found to report the width and height:

<code class="php"><?php
// Retrieve JPEG width and height without downloading/reading entire image.
function getjpegsize($img_loc) {
    $handle = fopen($img_loc, "rb") or die("Invalid file stream.");
    $new_block = NULL;
    if(!feof($handle)) {
        $new_block = fread($handle, 32);
        $i = 0;
        if($new_block[$i]=="\xFF" && $new_block[$i+1]=="\xD8" && $new_block[$i+2]=="\xFF" && $new_block[$i+3]=="\xE0") {
            $i += 4;
            if($new_block[$i+2]=="\x4A" && $new_block[$i+3]=="\x46" && $new_block[$i+4]=="\x49" && $new_block[$i+5]=="\x46" && $new_block[$i+6]=="\x00") {
                // Read block size and skip ahead to begin cycling through blocks in search of SOF marker
                $block_size = unpack("H*", $new_block[$i] . $new_block[$i+1]);
                $block_size = hexdec($block_size[1]);
                while(!feof($handle)) {
                    $i += $block_size;
                    $new_block .= fread($handle, $block_size);
                    if($new_block[$i]=="\xFF") {
                        // New block detected, check for SOF marker
                        $sof_marker = array("\xC0", "\xC1", "\xC2", "\xC3", "\xC5", "\xC6", "\xC7", "\xC8", "\xC9", "\xCA", "\xCB", "\xCD", "\xCE", "\xCF");
                        if(in_array($new_block[$i+1], $sof_marker)) {
                            // SOF marker detected. Width and height information is contained in bytes 4-7 after this byte.
                            $size_data = $new_block[$i+2] . $new_block[$i+3] . $new_block[$i+4] . $new_block[$i+5] . $new_block[$i+6] . $new_block[$i+7] . $new_block[$i+8];
                            $unpacked = unpack("H*", $size_data);
                            $unpacked = $unpacked[1];
                            $height = hexdec($unpacked[6] . $unpacked[7] . $unpacked[8] . $unpacked[9]);
                            $width = hexdec($unpacked[10] . $unpacked[11] . $unpacked[12] . $unpacked[13]);
                            return array($width, $height);
                        } else {
                            // Skip block marker and read block size
                            $i += 2;
                            $block_size = unpack("H*", $new_block[$i] . $new_block[$i+1]);
                            $block_size = hexdec($block_size[1]);
                        }
                    } else {
                        return FALSE;
                    }
                }
            }
        }
    }
    return FALSE;
}
?></code>

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