mojo/shell/fetcher.h

   1 // Copyright 2015 The Chromium Authors. All rights reserved.
   2 // Use of this source code is governed by a BSD-style license that can be
   3 // found in the LICENSE file.
   4
   5 #ifndef MOJO_SHELL_FETCHER_H_
   6 #define MOJO_SHELL_FETCHER_H_
   7
   8 #include "base/callback.h"
   9 #include "base/memory/scoped_ptr.h"
  10
  11 #include "mojo/services/network/public/interfaces/url_loader.mojom.h"
  12
  13 class GURL;
  14
  15 namespace base {
  16 class FilePath;
  17 class TaskRunner;
  18 }
  19
  20 namespace mojo {
  21 namespace shell {
  22
  23 // Fetcher abstracts getting an application by either file or http[s] URL.
  24 //
  25 // Although it is possible to use the Network implementation for http[s] URLs
  26 // (because the underlying net library knows how to handle them), it is
  27 // extremely slow because network responses must be copied to disk in order to
  28 // get a file handle we can use with dlopen.
  29 //
  30 // Until this is solved, we use two different implementations so that
  31 // performance isn't completely absymal.
  32 class Fetcher {
  33  public:
  34   // The param will be null in the case where the content could not be fetched.
  35   // Reasons include:
  36   // - network error
  37   // - 4x or 5x HTTP errors
  38   typedef base::Callback<void(scoped_ptr<Fetcher>)> FetchCallback;
  39
  40   Fetcher(const FetchCallback& fetch_callback);
  41   virtual ~Fetcher();
  42
  43   // Returns the original URL that was fetched.
  44   virtual const GURL& GetURL() const = 0;
  45
  46   // If the fetch resulted in a redirect, this returns the final URL after all
  47   // redirects. Otherwise, it returns an empty URL.
  48   virtual GURL GetRedirectURL() const = 0;
  49
  50   virtual URLResponsePtr AsURLResponse(base::TaskRunner* task_runner,
  51                                        uint32_t skip) = 0;
  52
  53   virtual void AsPath(
  54       base::TaskRunner* task_runner,
  55       base::Callback<void(const base::FilePath&, bool)> callback) = 0;
  56
  57   virtual std::string MimeType() = 0;
  58
  59   virtual bool HasMojoMagic() = 0;
  60
  61   virtual bool PeekFirstLine(std::string* line) = 0;
  62
  63   bool PeekContentHandler(std::string* mojo_shebang,
  64                           GURL* mojo_content_handler_url);
  65
  66  protected:
  67   static const char kMojoMagic[];
  68   static const size_t kMaxShebangLength;
  69
  70   FetchCallback loader_callback_;
  71 };
  72
  73 }  // namespace shell
  74 }  // namespace mojo
  75
  76 #endif  // MOJO_SHELL_FETCHER_H_