ppapi/native_client/src/trusted/plugin/temporary_file.cc

   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 #include "ppapi/native_client/src/trusted/plugin/temporary_file.h"
   6
   7 #include "native_client/src/include/portability_io.h"
   8 #include "native_client/src/shared/platform/nacl_check.h"
   9 #include "native_client/src/trusted/service_runtime/include/sys/stat.h"
  10
  11 #include "ppapi/cpp/core.h"
  12 #include "ppapi/cpp/instance.h"
  13 #include "ppapi/cpp/module.h"
  14 #include "ppapi/c/private/pp_file_handle.h"
  15
  16 #include "ppapi/native_client/src/trusted/plugin/plugin.h"
  17 #include "ppapi/native_client/src/trusted/plugin/utility.h"
  18
  19
  20 //////////////////////////////////////////////////////////////////////
  21 //  Temporary file access.
  22 //////////////////////////////////////////////////////////////////////
  23
  24 namespace plugin {
  25
  26 uint32_t TempFile::next_identifier = 0;
  27
  28 TempFile::TempFile(Plugin* plugin) : plugin_(plugin),
  29                                      existing_handle_(PP_kInvalidFileHandle) {
  30   PLUGIN_PRINTF(("TempFile::TempFile\n"));
  31   ++next_identifier;
  32   SNPRINTF(reinterpret_cast<char *>(identifier_), sizeof identifier_,
  33            "%" NACL_PRIu32, next_identifier);
  34 }
  35
  36 TempFile::~TempFile() {
  37   PLUGIN_PRINTF(("TempFile::~TempFile\n"));
  38 }
  39
  40 bool TempFile::SetExistingFd(PP_FileHandle handle) {
  41   // Check if we got a bad handle or if Open has already been called.
  42   if (handle == PP_kInvalidFileHandle || read_wrapper_.get() != NULL)
  43     return false;
  44   existing_handle_ = handle;
  45   return true;
  46 }
  47
  48 void TempFile::Open(const pp::CompletionCallback& cb, bool writeable) {
  49   PLUGIN_PRINTF(("TempFile::Open\n"));
  50   PP_FileHandle file_handle;
  51   if (existing_handle_ == PP_kInvalidFileHandle) {
  52     file_handle =
  53         plugin_->nacl_interface()->CreateTemporaryFile(plugin_->pp_instance());
  54   } else {
  55     file_handle = existing_handle_;
  56   }
  57
  58   pp::Core* core = pp::Module::Get()->core();
  59   if (file_handle == PP_kInvalidFileHandle) {
  60     PLUGIN_PRINTF(("TempFile::Open failed w/ PP_kInvalidFileHandle\n"));
  61     core->CallOnMainThread(0, cb, PP_ERROR_FAILED);
  62   }
  63
  64 #if NACL_WINDOWS
  65   HANDLE handle = file_handle;
  66
  67   //////// Now try the posix view.
  68   int rdwr_flag = writeable ? _O_RDWR : _O_RDONLY;
  69   int32_t posix_desc = _open_osfhandle(reinterpret_cast<intptr_t>(handle),
  70                                        rdwr_flag | _O_BINARY
  71                                        | _O_TEMPORARY | _O_SHORT_LIVED );
  72   if (posix_desc == -1) {
  73     PLUGIN_PRINTF(("TempFile::Open failed to convert HANDLE to posix\n"));
  74     // Close the Windows HANDLE if it can't be converted.
  75     CloseHandle(handle);
  76   }
  77   int32_t fd = posix_desc;
  78 #else
  79   int32_t fd = file_handle;
  80 #endif
  81
  82   if (fd < 0) {
  83     PLUGIN_PRINTF(("TempFile::Open failed\n"));
  84     core->CallOnMainThread(0, cb, PP_ERROR_FAILED);
  85     return;
  86   }
  87
  88   // dup the fd to make allow making a non-Quota-based wrapper.
  89   // sel_ldr currently does not allow loading from Quota-backed descs,
  90   // only plain host descs.  It's probably good hygiene to separate the
  91   // read wrapper from the write wrapper anyway.
  92   int32_t read_fd = DUP(fd);
  93   if (read_fd == NACL_NO_FILE_DESC) {
  94     PLUGIN_PRINTF(("TempFile::Open DUP failed\n"));
  95     core->CallOnMainThread(0, cb, PP_ERROR_FAILED);
  96     return;
  97   }
  98
  99   // The descriptor for a writeable file needs to have quota management.
 100   if (writeable) {
 101     write_wrapper_.reset(
 102         plugin_->wrapper_factory()->MakeFileDescQuota(fd, O_RDWR, identifier_));
 103   }
 104   read_wrapper_.reset(
 105       plugin_->wrapper_factory()->MakeFileDesc(read_fd, O_RDONLY));
 106   core->CallOnMainThread(0, cb, PP_OK);
 107 }
 108
 109 bool TempFile::Reset() {
 110   PLUGIN_PRINTF(("TempFile::Reset\n"));
 111   // Use the read_wrapper_ to reset the file pos.  The write_wrapper_ is also
 112   // backed by the same file, so it should also reset.
 113   CHECK(read_wrapper_.get() != NULL);
 114   nacl_off64_t newpos = read_wrapper_->Seek(0, SEEK_SET);
 115   return newpos >= 0;
 116 }
 117
 118 }  // namespace plugin