Extract static content handling into reusable class

src/main/php/web/handler/FilesFrom.class.php

@@ -1,20 +1,16 @@
 <?php namespace web\handler;
 
 use io\{File, Path};
-use util\MimeType;
-use web\io\Ranges;
-use web\{Handler, Headers};
+use web\Handler;
+use web\io\StaticContent;
 
 class FilesFrom implements Handler {
-  const BOUNDARY  = '594fa07300f865fe';
-  const CHUNKSIZE = 8192;
-
-  private $path;
-  private $headers= [];
+  private $path, $content;
 
   /** @param io.Path|io.Folder|string $path */
   public function __construct($path) {
     $this->path= $path instanceof Path ? $path : new Path($path);
+    $this->content= new StaticContent();
   }
 
   /** @return io.Path */
@@ -27,7 +23,7 @@ public function path() { return $this->path; }
    * @return self
    */
   public function with($headers) {
-    $this->headers= $headers;
+    $this->content->with($headers);
     return $this;
   }
 
@@ -61,128 +57,20 @@ public function handle($request, $response) {
       $file= $target->asFile();
     }
 
-    return $this->serve($request, $response, $file);
-  }
-
-  /**
-   * Copies a given amount of bytes from the specified file to the output
-   *
-   * @param  web.io.Output $out
-   * @param  io.File $file
-   * @param  web.io.Range $range
-   * @return iterable
-   */
-  private function copy($out, $file, $range) {
-    $file->seek($range->start());
-
-    $length= $range->length();
-    while ($length && $chunk= $file->read(min(self::CHUNKSIZE, $length))) {
-      yield 'write' => null;
-      $out->write($chunk);
-      $length-= strlen($chunk);
-    }
+    return $this->content->serve($request, $response, $file);
   }
 
   /**
-   * Serves a single file
+   * Serves a single file.
    *
+   * @deprecated Use `web.io.StaticContent` directly!
    * @param   web.Request $request
    * @param   web.Response $response
    * @param   ?io.File|io.Path|string $target
    * @param   ?string $mimeType
    * @return  iterable
    */
   public function serve($request, $response, $target, $mimeType= null) {
-    if (null === $target || ($file= $target instanceof File ? $target : new File($target)) && !$file->exists()) {
-      $response->answer(404, 'Not Found');
-      $response->send('The file \''.$request->uri()->path().'\' was not found', 'text/plain');
-      return;
-    }
-
-    $lastModified= $file->lastModified();
-    if ($conditional= $request->header('If-Modified-Since')) {
-      if ($lastModified <= strtotime($conditional)) {
-        $response->answer(304, 'Not Modified');
-        $response->flush();
-        return;
-      }
-    }
-
-    $mimeType ?? $mimeType= MimeType::getByFileName($file->filename);
-    $response->header('Accept-Ranges', 'bytes');
-    $response->header('Last-Modified', Headers::date($lastModified));
-    $response->header('X-Content-Type-Options', 'nosniff');
-    $headers= is_callable($this->headers) ? ($this->headers)($request->uri(), $target, $mimeType) : $this->headers;
-    foreach ($headers as $name => $value) {
-      $response->header($name, $value);
-    }
-
-    if (null === ($ranges= Ranges::in($request->header('Range'), $file->size()))) {
-      $response->answer(200, 'OK');
-      $response->header('Content-Type', $mimeType);
-
-      if ('HEAD' === $request->method()) {
-        $response->header('Content-Length', $file->size());
-        $response->flush();
-      } else {
-        $out= $response->stream($file->size());
-        $file->open(File::READ);
-        try {
-          do {
-            yield 'write' => null;
-            $out->write($file->read(self::CHUNKSIZE));
-          } while (!$file->eof());
-        } finally {
-          $file->close();
-          $out->close();
-        }
-      }
-      return;
-    }
-
-    if (!$ranges->satisfiable() || 'bytes' !== $ranges->unit()) {
-      $response->answer(416, 'Range Not Satisfiable');
-      $response->header('Content-Range', 'bytes */'.$ranges->complete());
-      $response->flush();
-      return;
-    }
-
-    $file->open(File::READ);
-    $response->answer(206, 'Partial Content');
-
-    try {
-      if ($range= $ranges->single()) {
-        $response->header('Content-Type', $mimeType);
-        $response->header('Content-Range', $ranges->format($range));
-
-        $out= $response->stream($range->length());
-        yield from $this->copy($out, $file, $range);
-      } else {
-        $headers= [];
-        $trailer= "\r\n--".self::BOUNDARY."--\r\n";
-        $length= strlen($trailer);
-
-        foreach ($ranges->sets() as $i => $range) {
-          $headers[$i]= $header= sprintf(
-            "\r\n--%s\r\nContent-Type: %s\r\nContent-Range: %s\r\n\r\n",
-            self::BOUNDARY,
-            $mimeType,
-            $ranges->format($range)
-          );
-          $length+= strlen($header) + $range->length();
-        }
-        $response->header('Content-Type', 'multipart/byteranges; boundary='.self::BOUNDARY);
-
-        $out= $response->stream($length);
-        foreach ($ranges->sets() as $i => $range) {
-          $out->write($headers[$i]);
-          yield from $this->copy($out, $file, $range);
-        }
-        $out->write($trailer);
-      }
-    } finally {
-      $file->close();
-      $out->close();
-    }
+    return $this->content->serve($request, $response, $target, $mimeType);
   }
 }

src/main/php/web/io/StaticContent.class.php

@@ -0,0 +1,160 @@
+<?php namespace web\io;
+
+use io\File;
+use util\MimeType;
+use web\Headers;
+
+/**
+ * Serves static content by streaming given files. Handles HEAD,
+ * conditional and byte range requests. Suppresses content type
+ * detection by adding `X-Content-Type-Options: nosniff`.
+ *
+ * ```php
+ * $content= (new StaticContent())->with(['Cache-Control' => '...']);
+ * return $content->serve($req, $res, new File('...'), 'image/gif');
+ * ```
+ *
+ * @test web.unittest.io.StaticContentTest
+ * @see  web.handler.FilesFrom
+ * @see  https://developer.mozilla.org/en-US/docs/Web/HTTP/Headers/X-Content-Type-Options
+ */
+class StaticContent {
+  const BOUNDARY  = '594fa07300f865fe';
+  const CHUNKSIZE = 8192;
+
+  private $headers= [];
+
+  /**
+   * Adds headers to successful responses, either from an array or a function.
+   *
+   * @param  [:string]|function(util.URI, io.File, string): iterable $headers
+   * @return self
+   */
+  public function with($headers) {
+    $this->headers= $headers;
+    return $this;
+  }
+
+  /**
+   * Copies a given amount of bytes from the specified file to the output
+   *
+   * @param  web.io.Output $out
+   * @param  io.File $file
+   * @param  web.io.Range $range
+   * @return iterable
+   */
+  private function copy($out, $file, $range) {
+    $file->seek($range->start());
+
+    $length= $range->length();
+    while ($length && $chunk= $file->read(min(self::CHUNKSIZE, $length))) {
+      yield 'write' => $out;
+      $out->write($chunk);
+      $length-= strlen($chunk);
+    }
+  }
+
+  /**
+   * Serves a single file. If no mime type is given, it is detected from
+   * the given file's extension.
+   *
+   * @param   web.Request $request
+   * @param   web.Response $response
+   * @param   ?io.File|io.Path|string $target
+   * @param   ?string $mimeType
+   * @return  iterable
+   */
+  public function serve($request, $response, $target, $mimeType= null) {
+    if (null === $target || ($file= $target instanceof File ? $target : new File($target)) && !$file->exists()) {
+      $response->answer(404, 'Not Found');
+      $response->send('The file \''.$request->uri()->path().'\' was not found', 'text/plain');
+      return;
+    }
+
+    $lastModified= $file->lastModified();
+    if ($conditional= $request->header('If-Modified-Since')) {
+      if ($lastModified <= strtotime($conditional)) {
+        $response->answer(304, 'Not Modified');
+        $response->flush();
+        return;
+      }
+    }
+
+    $mimeType ?? $mimeType= MimeType::getByFileName($file->filename);
+    $response->header('Accept-Ranges', 'bytes');
+    $response->header('Last-Modified', Headers::date($lastModified));
+    $response->header('X-Content-Type-Options', 'nosniff');
+    $headers= is_callable($this->headers) ? ($this->headers)($request->uri(), $target, $mimeType) : $this->headers;
+    foreach ($headers as $name => $value) {
+      $response->header($name, $value);
+    }
+
+    if (null === ($ranges= Ranges::in($request->header('Range'), $file->size()))) {
+      $response->answer(200, 'OK');
+      $response->header('Content-Type', $mimeType);
+
+      if ('HEAD' === $request->method()) {
+        $response->header('Content-Length', $file->size());
+        $response->flush();
+      } else {
+        $out= $response->stream($file->size());
+        $file->open(File::READ);
+        try {
+          do {
+            yield 'write' => $out;
+            $out->write($file->read(self::CHUNKSIZE));
+          } while (!$file->eof());
+        } finally {
+          $file->close();
+          $out->close();
+        }
+      }
+      return;
+    }
+
+    if (!$ranges->satisfiable() || 'bytes' !== $ranges->unit()) {
+      $response->answer(416, 'Range Not Satisfiable');
+      $response->header('Content-Range', 'bytes */'.$ranges->complete());
+      $response->flush();
+      return;
+    }
+
+    $file->open(File::READ);
+    $response->answer(206, 'Partial Content');
+
+    try {
+      if ($range= $ranges->single()) {
+        $response->header('Content-Type', $mimeType);
+        $response->header('Content-Range', $ranges->format($range));
+
+        $out= $response->stream($range->length());
+        yield from $this->copy($out, $file, $range);
+      } else {
+        $headers= [];
+        $trailer= "\r\n--".self::BOUNDARY."--\r\n";
+        $length= strlen($trailer);
+
+        foreach ($ranges->sets() as $i => $range) {
+          $headers[$i]= $header= sprintf(
+            "\r\n--%s\r\nContent-Type: %s\r\nContent-Range: %s\r\n\r\n",
+            self::BOUNDARY,
+            $mimeType,
+            $ranges->format($range)
+          );
+          $length+= strlen($header) + $range->length();
+        }
+        $response->header('Content-Type', 'multipart/byteranges; boundary='.self::BOUNDARY);
+
+        $out= $response->stream($length);
+        foreach ($ranges->sets() as $i => $range) {
+          $out->write($headers[$i]);
+          yield from $this->copy($out, $file, $range);
+        }
+        $out->write($trailer);
+      }
+    } finally {
+      $file->close();
+      $out->close();
+    }
+  }
+}