chrome/service/service_utility_process_host.h

   1 // Copyright (c) 2012 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 CHROME_SERVICE_SERVICE_UTILITY_PROCESS_HOST_H_
   6 #define CHROME_SERVICE_SERVICE_UTILITY_PROCESS_HOST_H_
   7
   8 #include "build/build_config.h"
   9
  10 #include <string>
  11 #include <vector>
  12
  13 #include "base/basictypes.h"
  14 #include "base/files/file_path.h"
  15 #include "base/memory/ref_counted.h"
  16 #include "base/memory/scoped_ptr.h"
  17 #include "base/process/process.h"
  18 #include "content/public/common/child_process_host_delegate.h"
  19 #include "ipc/ipc_channel.h"
  20 #include "printing/pdf_render_settings.h"
  21
  22 namespace base {
  23 class CommandLine;
  24 class MessageLoopProxy;
  25 class ScopedTempDir;
  26 }  // namespace base
  27
  28 namespace content {
  29 class ChildProcessHost;
  30 }
  31
  32 namespace printing {
  33 class Emf;
  34 struct PageRange;
  35 struct PrinterCapsAndDefaults;
  36 struct PrinterSemanticCapsAndDefaults;
  37 }  // namespace printing
  38
  39 // Acts as the service-side host to a utility child process. A
  40 // utility process is a short-lived sandboxed process that is created to run
  41 // a specific task.
  42 class ServiceUtilityProcessHost : public content::ChildProcessHostDelegate {
  43  public:
  44   // Consumers of ServiceUtilityProcessHost must implement this interface to
  45   // get results back.  All functions are called on the thread passed along
  46   // to ServiceUtilityProcessHost.
  47   class Client : public base::RefCountedThreadSafe<Client> {
  48    public:
  49     Client() {}
  50
  51     // Called when the child process died before a reply was receieved.
  52     virtual void OnChildDied() {}
  53
  54     // Called when at least one page in the specified PDF has been rendered
  55     // successfully into |metafile|.
  56     virtual void OnRenderPDFPagesToMetafileSucceeded(
  57         const printing::Emf& metafile,
  58         int highest_rendered_page_number,
  59         double scale_factor) {}
  60     // Called when no page in the passed in PDF could be rendered.
  61     virtual void OnRenderPDFPagesToMetafileFailed() {}
  62
  63     // Called when the printer capabilities and defaults have been
  64     // retrieved successfully or if retrieval failed.
  65     virtual void OnGetPrinterCapsAndDefaults(
  66         bool succedded,
  67         const std::string& printer_name,
  68         const printing::PrinterCapsAndDefaults& caps_and_defaults) {}
  69
  70     // Called when the printer capabilities and defaults have been
  71     // retrieved successfully or if retrieval failed.
  72     virtual void OnGetPrinterSemanticCapsAndDefaults(
  73         bool succedded,
  74         const std::string& printer_name,
  75         const printing::PrinterSemanticCapsAndDefaults& caps_and_defaults) {}
  76
  77    protected:
  78     virtual ~Client() {}
  79
  80    private:
  81     friend class base::RefCountedThreadSafe<Client>;
  82     friend class ServiceUtilityProcessHost;
  83
  84     // Invoked when a metafile file is ready.
  85     void MetafileAvailable(const base::FilePath& metafile_path,
  86                            int highest_rendered_page_number,
  87                            double scale_factor);
  88
  89     DISALLOW_COPY_AND_ASSIGN(Client);
  90   };
  91
  92   ServiceUtilityProcessHost(Client* client,
  93                             base::MessageLoopProxy* client_message_loop_proxy);
  94   virtual ~ServiceUtilityProcessHost();
  95
  96   // Starts a process to render the specified pages in the given PDF file into
  97   // a metafile. Currently only implemented for Windows. If the PDF has fewer
  98   // pages than the specified page ranges, it will render as many as available.
  99   bool StartRenderPDFPagesToMetafile(
 100       const base::FilePath& pdf_path,
 101       const printing::PdfRenderSettings& render_settings,
 102       const std::vector<printing::PageRange>& page_ranges);
 103
 104   // Starts a process to get capabilities and defaults for the specified
 105   // printer. Used on Windows to isolate the service process from printer driver
 106   // crashes by executing this in a separate process. The process does not run
 107   // in a sandbox.
 108   bool StartGetPrinterCapsAndDefaults(const std::string& printer_name);
 109
 110   // Starts a process to get capabilities and defaults for the specified
 111   // printer. Used on Windows to isolate the service process from printer driver
 112   // crashes by executing this in a separate process. The process does not run
 113   // in a sandbox. Returns result as printing::PrinterSemanticCapsAndDefaults.
 114   bool StartGetPrinterSemanticCapsAndDefaults(const std::string& printer_name);
 115
 116  protected:
 117   // Allows this method to be overridden for tests.
 118   virtual base::FilePath GetUtilityProcessCmd();
 119
 120   // ChildProcessHostDelegate implementation:
 121   virtual void OnChildDisconnected() OVERRIDE;
 122   virtual bool OnMessageReceived(const IPC::Message& message) OVERRIDE;
 123   virtual base::ProcessHandle GetHandle() const OVERRIDE;
 124
 125  private:
 126   // Starts a process.  Returns true iff it succeeded. |exposed_dir| is the
 127   // path to the exposed to the sandbox. This is ignored if |no_sandbox| is
 128   // true.
 129   bool StartProcess(bool no_sandbox, const base::FilePath& exposed_dir);
 130
 131   // Launch the child process synchronously.
 132   // TODO(sanjeevr): Determine whether we need to make the launch asynchronous.
 133   // |exposed_dir| is the path to tbe exposed to the sandbox. This is ignored
 134   // if |no_sandbox| is true.
 135   bool Launch(base::CommandLine* cmd_line,
 136               bool no_sandbox,
 137               const base::FilePath& exposed_dir);
 138
 139   base::ProcessHandle handle() const { return handle_; }
 140
 141   // Messages handlers:
 142   void OnRenderPDFPagesToMetafilesSucceeded(
 143       const std::vector<printing::PageRange>& page_ranges,
 144       double scale_factor);
 145   void OnRenderPDFPagesToMetafileFailed();
 146   void OnGetPrinterCapsAndDefaultsSucceeded(
 147       const std::string& printer_name,
 148       const printing::PrinterCapsAndDefaults& caps_and_defaults);
 149   void OnGetPrinterCapsAndDefaultsFailed(const std::string& printer_name);
 150   void OnGetPrinterSemanticCapsAndDefaultsSucceeded(
 151       const std::string& printer_name,
 152       const printing::PrinterSemanticCapsAndDefaults& caps_and_defaults);
 153   void OnGetPrinterSemanticCapsAndDefaultsFailed(
 154       const std::string& printer_name);
 155
 156   scoped_ptr<content::ChildProcessHost> child_process_host_;
 157   base::ProcessHandle handle_;
 158   // A pointer to our client interface, who will be informed of progress.
 159   scoped_refptr<Client> client_;
 160   scoped_refptr<base::MessageLoopProxy> client_message_loop_proxy_;
 161   bool waiting_for_reply_;
 162   // The base path to the temp file where the metafile will be written to.
 163   base::FilePath metafile_path_;
 164   // The temporary folder created for the metafile.
 165   scoped_ptr<base::ScopedTempDir> scratch_metafile_dir_;
 166   // Start time of operation.
 167   base::Time start_time_;
 168
 169   DISALLOW_COPY_AND_ASSIGN(ServiceUtilityProcessHost);
 170 };
 171
 172 #endif  // CHROME_SERVICE_SERVICE_UTILITY_PROCESS_HOST_H_