net/url_request/url_request_file_job.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 // For loading files, we make use of overlapped i/o to ensure that reading from
   6 // the filesystem (e.g., a network filesystem) does not block the calling
   7 // thread.  An alternative approach would be to use a background thread or pool
   8 // of threads, but it seems better to leverage the operating system's ability
   9 // to do background file reads for us.
  10 //
  11 // Since overlapped reads require a 'static' buffer for the duration of the
  12 // asynchronous read, the URLRequestFileJob keeps a buffer as a member var.  In
  13 // URLRequestFileJob::Read, data is simply copied from the object's buffer into
  14 // the given buffer.  If there is no data to copy, the URLRequestFileJob
  15 // attempts to read more from the file to fill its buffer.  If reading from the
  16 // file does not complete synchronously, then the URLRequestFileJob waits for a
  17 // signal from the OS that the overlapped read has completed.  It does so by
  18 // leveraging the MessageLoop::WatchObject API.
  19
  20 #include "net/url_request/url_request_file_job.h"
  21
  22 #include "base/bind.h"
  23 #include "base/compiler_specific.h"
  24 #include "base/files/file_util.h"
  25 #include "base/message_loop/message_loop.h"
  26 #include "base/profiler/scoped_tracker.h"
  27 #include "base/strings/string_util.h"
  28 #include "base/synchronization/lock.h"
  29 #include "base/task_runner.h"
  30 #include "base/threading/thread_restrictions.h"
  31 #include "build/build_config.h"
  32 #include "net/base/file_stream.h"
  33 #include "net/base/filename_util.h"
  34 #include "net/base/io_buffer.h"
  35 #include "net/base/load_flags.h"
  36 #include "net/base/mime_util.h"
  37 #include "net/base/net_errors.h"
  38 #include "net/filter/filter.h"
  39 #include "net/http/http_util.h"
  40 #include "net/url_request/url_request_error_job.h"
  41 #include "net/url_request/url_request_file_dir_job.h"
  42 #include "url/gurl.h"
  43
  44 #if defined(OS_WIN)
  45 #include "base/win/shortcut.h"
  46 #endif
  47
  48 namespace net {
  49
  50 URLRequestFileJob::FileMetaInfo::FileMetaInfo()
  51     : file_size(0),
  52       mime_type_result(false),
  53       file_exists(false),
  54       is_directory(false) {
  55 }
  56
  57 URLRequestFileJob::URLRequestFileJob(
  58     URLRequest* request,
  59     NetworkDelegate* network_delegate,
  60     const base::FilePath& file_path,
  61     const scoped_refptr<base::TaskRunner>& file_task_runner)
  62     : URLRequestJob(request, network_delegate),
  63       file_path_(file_path),
  64       stream_(new FileStream(file_task_runner)),
  65       file_task_runner_(file_task_runner),
  66       remaining_bytes_(0),
  67       weak_ptr_factory_(this) {}
  68
  69 void URLRequestFileJob::Start() {
  70   FileMetaInfo* meta_info = new FileMetaInfo();
  71   file_task_runner_->PostTaskAndReply(
  72       FROM_HERE,
  73       base::Bind(&URLRequestFileJob::FetchMetaInfo, file_path_,
  74                  base::Unretained(meta_info)),
  75       base::Bind(&URLRequestFileJob::DidFetchMetaInfo,
  76                  weak_ptr_factory_.GetWeakPtr(),
  77                  base::Owned(meta_info)));
  78 }
  79
  80 void URLRequestFileJob::Kill() {
  81   stream_.reset();
  82   weak_ptr_factory_.InvalidateWeakPtrs();
  83
  84   URLRequestJob::Kill();
  85 }
  86
  87 bool URLRequestFileJob::ReadRawData(IOBuffer* dest,
  88                                     int dest_size,
  89                                     int* bytes_read) {
  90   DCHECK_NE(dest_size, 0);
  91   DCHECK(bytes_read);
  92   DCHECK_GE(remaining_bytes_, 0);
  93
  94   if (remaining_bytes_ < dest_size)
  95     dest_size = static_cast<int>(remaining_bytes_);
  96
  97   // If we should copy zero bytes because |remaining_bytes_| is zero, short
  98   // circuit here.
  99   if (!dest_size) {
 100     *bytes_read = 0;
 101     return true;
 102   }
 103
 104   int rv = stream_->Read(dest,
 105                          dest_size,
 106                          base::Bind(&URLRequestFileJob::DidRead,
 107                                     weak_ptr_factory_.GetWeakPtr(),
 108                                     make_scoped_refptr(dest)));
 109   if (rv >= 0) {
 110     // Data is immediately available.
 111     *bytes_read = rv;
 112     remaining_bytes_ -= rv;
 113     DCHECK_GE(remaining_bytes_, 0);
 114     return true;
 115   }
 116
 117   // Otherwise, a read error occured.  We may just need to wait...
 118   if (rv == ERR_IO_PENDING) {
 119     SetStatus(URLRequestStatus(URLRequestStatus::IO_PENDING, 0));
 120   } else {
 121     NotifyDone(URLRequestStatus(URLRequestStatus::FAILED, rv));
 122   }
 123   return false;
 124 }
 125
 126 bool URLRequestFileJob::IsRedirectResponse(GURL* location,
 127                                            int* http_status_code) {
 128   if (meta_info_.is_directory) {
 129     // This happens when we discovered the file is a directory, so needs a
 130     // slash at the end of the path.
 131     std::string new_path = request_->url().path();
 132     new_path.push_back('/');
 133     GURL::Replacements replacements;
 134     replacements.SetPathStr(new_path);
 135
 136     *location = request_->url().ReplaceComponents(replacements);
 137     *http_status_code = 301;  // simulate a permanent redirect
 138     return true;
 139   }
 140
 141 #if defined(OS_WIN)
 142   // Follow a Windows shortcut.
 143   // We just resolve .lnk file, ignore others.
 144   if (!LowerCaseEqualsASCII(file_path_.Extension(), ".lnk"))
 145     return false;
 146
 147   base::FilePath new_path = file_path_;
 148   bool resolved;
 149   resolved = base::win::ResolveShortcut(new_path, &new_path, NULL);
 150
 151   // If shortcut is not resolved succesfully, do not redirect.
 152   if (!resolved)
 153     return false;
 154
 155   *location = FilePathToFileURL(new_path);
 156   *http_status_code = 301;
 157   return true;
 158 #else
 159   return false;
 160 #endif
 161 }
 162
 163 Filter* URLRequestFileJob::SetupFilter() const {
 164   // Bug 9936 - .svgz files needs to be decompressed.
 165   return LowerCaseEqualsASCII(file_path_.Extension(), ".svgz")
 166       ? Filter::GZipFactory() : NULL;
 167 }
 168
 169 bool URLRequestFileJob::GetMimeType(std::string* mime_type) const {
 170   DCHECK(request_);
 171   if (meta_info_.mime_type_result) {
 172     *mime_type = meta_info_.mime_type;
 173     return true;
 174   }
 175   return false;
 176 }
 177
 178 void URLRequestFileJob::SetExtraRequestHeaders(
 179     const HttpRequestHeaders& headers) {
 180   std::string range_header;
 181   if (headers.GetHeader(HttpRequestHeaders::kRange, &range_header)) {
 182     // We only care about "Range" header here.
 183     std::vector<HttpByteRange> ranges;
 184     if (HttpUtil::ParseRangeHeader(range_header, &ranges)) {
 185       if (ranges.size() == 1) {
 186         byte_range_ = ranges[0];
 187       } else {
 188         // We don't support multiple range requests in one single URL request,
 189         // because we need to do multipart encoding here.
 190         // TODO(hclam): decide whether we want to support multiple range
 191         // requests.
 192         NotifyDone(URLRequestStatus(URLRequestStatus::FAILED,
 193                                     ERR_REQUEST_RANGE_NOT_SATISFIABLE));
 194       }
 195     }
 196   }
 197 }
 198
 199 void URLRequestFileJob::OnSeekComplete(int64 result) {
 200 }
 201
 202 void URLRequestFileJob::OnReadComplete(net::IOBuffer* buf, int result) {
 203 }
 204
 205 URLRequestFileJob::~URLRequestFileJob() {
 206 }
 207
 208 void URLRequestFileJob::FetchMetaInfo(const base::FilePath& file_path,
 209                                       FileMetaInfo* meta_info) {
 210   base::File::Info file_info;
 211   meta_info->file_exists = base::GetFileInfo(file_path, &file_info);
 212   if (meta_info->file_exists) {
 213     meta_info->file_size = file_info.size;
 214     meta_info->is_directory = file_info.is_directory;
 215   }
 216   // On Windows GetMimeTypeFromFile() goes to the registry. Thus it should be
 217   // done in WorkerPool.
 218   meta_info->mime_type_result = GetMimeTypeFromFile(file_path,
 219                                                     &meta_info->mime_type);
 220 }
 221
 222 void URLRequestFileJob::DidFetchMetaInfo(const FileMetaInfo* meta_info) {
 223   meta_info_ = *meta_info;
 224
 225   // We use URLRequestFileJob to handle files as well as directories without
 226   // trailing slash.
 227   // If a directory does not exist, we return ERR_FILE_NOT_FOUND. Otherwise,
 228   // we will append trailing slash and redirect to FileDirJob.
 229   // A special case is "\" on Windows. We should resolve as invalid.
 230   // However, Windows resolves "\" to "C:\", thus reports it as existent.
 231   // So what happens is we append it with trailing slash and redirect it to
 232   // FileDirJob where it is resolved as invalid.
 233   if (!meta_info_.file_exists) {
 234     DidOpen(ERR_FILE_NOT_FOUND);
 235     return;
 236   }
 237   if (meta_info_.is_directory) {
 238     DidOpen(OK);
 239     return;
 240   }
 241
 242   int flags = base::File::FLAG_OPEN |
 243               base::File::FLAG_READ |
 244               base::File::FLAG_ASYNC;
 245   int rv = stream_->Open(file_path_, flags,
 246                          base::Bind(&URLRequestFileJob::DidOpen,
 247                                     weak_ptr_factory_.GetWeakPtr()));
 248   if (rv != ERR_IO_PENDING)
 249     DidOpen(rv);
 250 }
 251
 252 void URLRequestFileJob::DidOpen(int result) {
 253   // TODO(vadimt): Remove ScopedTracker below once crbug.com/423948 is fixed.
 254   tracked_objects::ScopedTracker tracking_profile(
 255       FROM_HERE_WITH_EXPLICIT_FUNCTION("423948 URLRequestFileJob::DidOpen"));
 256
 257   if (result != OK) {
 258     NotifyDone(URLRequestStatus(URLRequestStatus::FAILED, result));
 259     return;
 260   }
 261
 262   if (!byte_range_.ComputeBounds(meta_info_.file_size)) {
 263     NotifyDone(URLRequestStatus(URLRequestStatus::FAILED,
 264                ERR_REQUEST_RANGE_NOT_SATISFIABLE));
 265     return;
 266   }
 267
 268   remaining_bytes_ = byte_range_.last_byte_position() -
 269                      byte_range_.first_byte_position() + 1;
 270   DCHECK_GE(remaining_bytes_, 0);
 271
 272   if (remaining_bytes_ > 0 && byte_range_.first_byte_position() != 0) {
 273     // TODO(vadimt): Remove ScopedTracker below once crbug.com/423948 is fixed.
 274     tracked_objects::ScopedTracker tracking_profile1(
 275         FROM_HERE_WITH_EXPLICIT_FUNCTION(
 276             "423948 URLRequestFileJob::DidOpen 1"));
 277
 278     int rv = stream_->Seek(base::File::FROM_BEGIN,
 279                            byte_range_.first_byte_position(),
 280                            base::Bind(&URLRequestFileJob::DidSeek,
 281                                       weak_ptr_factory_.GetWeakPtr()));
 282     if (rv != ERR_IO_PENDING) {
 283       // stream_->Seek() failed, so pass an intentionally erroneous value
 284       // into DidSeek().
 285       DidSeek(-1);
 286     }
 287   } else {
 288     // We didn't need to call stream_->Seek() at all, so we pass to DidSeek()
 289     // the value that would mean seek success. This way we skip the code
 290     // handling seek failure.
 291     DidSeek(byte_range_.first_byte_position());
 292   }
 293 }
 294
 295 void URLRequestFileJob::DidSeek(int64 result) {
 296   OnSeekComplete(result);
 297   if (result != byte_range_.first_byte_position()) {
 298     NotifyDone(URLRequestStatus(URLRequestStatus::FAILED,
 299                                 ERR_REQUEST_RANGE_NOT_SATISFIABLE));
 300     return;
 301   }
 302
 303   set_expected_content_size(remaining_bytes_);
 304   NotifyHeadersComplete();
 305 }
 306
 307 void URLRequestFileJob::DidRead(scoped_refptr<net::IOBuffer> buf, int result) {
 308   if (result > 0) {
 309     SetStatus(URLRequestStatus());  // Clear the IO_PENDING status
 310     remaining_bytes_ -= result;
 311     DCHECK_GE(remaining_bytes_, 0);
 312   }
 313
 314   OnReadComplete(buf.get(), result);
 315   buf = NULL;
 316
 317   if (result == 0) {
 318     NotifyDone(URLRequestStatus());
 319   } else if (result < 0) {
 320     NotifyDone(URLRequestStatus(URLRequestStatus::FAILED, result));
 321   }
 322
 323   NotifyReadComplete(result);
 324 }
 325
 326 }  // namespace net