thumb: dynamic image relay with resize option

Generate image with requested height from data source, which should be
bypassed by the server if target file exists.

Copied from Lijtweg at commit v2.5-58-gac5434f0af (2017-12-12).

diff --git a/thumb/.gitignore b/thumb/.gitignore
new file mode 100644 (file)
index 0000000..34bbc9f
--- /dev/null
+++ b/thumb/.gitignore
@@ -0,0 +1 @@
+/[1-9]*/

diff --git a/thumb/.htaccess b/thumb/.htaccess
new file mode 100644 (file)
index 0000000..c63c79e
--- /dev/null
+++ b/thumb/.htaccess
@@ -0,0 +1,3 @@
+<IfModule mod_headers.c>
+       Header set Cache-Control "max-age=2628000, immutable"
+</IfModule>

diff --git a/thumb/index.php b/thumb/index.php
new file mode 100644 (file)
index 0000000..b49ca6e
--- /dev/null
+++ b/thumb/index.php
@@ -0,0 +1,34 @@
+<?php
+ob_clean();
+
+list ($height, $imgarg) = explode('/', ltrim($Args, '/'), 2);
+$width= 1000;
+$imgpath = "data/$imgarg";
+
+if (!file_exists($imgpath)) {
+       http_response_code(404);
+       exit;
+}
+
+$target = preg_replace("{^data/}", "thumb/$height/", $imgpath, 1);
+if (!file_exists($target)) {
+       @mkdir(dirname($target), 0777, TRUE);
+
+       $cmd = implode(' ', array_map('escapeshellarg', [
+               'convert',
+               '-trim',
+               '-resize', "${width}x${height}",
+               '-quality', '90%',
+               $imgpath, $target
+       ]));
+       $return = shell_exec("$cmd 2>&1");
+       if ($return) {
+               http_response_code(500);
+               trigger_error("thumbnail creation failed: $return", E_USER_WARNING);
+               exit;
+       }
+}
+
+header('Content-type: '.mime_content_type($target));
+readfile($target);
+exit;