content/browser/download/download_item

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This source file includes following definitions.
DeleteDownloadedFile
DeleteDownloadedFileDone
DownloadFileDetach
DownloadFileCancel
IsDownloadResumptionEnabled
weak_ptr_factory_
weak_ptr_factory_
weak_ptr_factory_
AddObserver
RemoveObserver
UpdateObservers
ValidateDangerousDownload
StealDangerousDownload
Pause
Resume
Cancel
Remove
OpenDownload
ShowDownloadInShell
GetId
GetState
GetLastReason
IsPaused
IsTemporary
CanResume
IsDone
GetURL
GetUrlChain
GetOriginalUrl
GetReferrerUrl
GetTabUrl
GetTabReferrerUrl
GetSuggestedFilename
GetContentDisposition
GetMimeType
GetOriginalMimeType
GetRemoteAddress
HasUserGesture
GetTransitionType
GetLastModifiedTime
GetETag
IsSavePackageDownload
GetFullPath
GetTargetFilePath
GetForcedFilePath
GetFileNameToReportUser
GetTargetDisposition
GetHash
GetHashState
GetFileExternallyRemoved
DeleteFile
IsDangerous
GetDangerType
TimeRemaining
CurrentSpeed
PercentComplete
AllDataSaved
GetTotalBytes
GetReceivedBytes
GetStartTime
GetEndTime
CanShowInFolder
CanOpenDownload
ShouldOpenFileBasedOnExtension
GetOpenWhenComplete
GetAutoOpened
GetOpened
GetBrowserContext
GetWebContents
OnContentCheckCompleted
SetOpenWhenComplete
SetIsTemporary
SetOpened
SetDisplayName
DebugString
GetResumeMode
MergeOriginInfoOnResume
NotifyRemoved
OnDownloadedFileRemoved
DestinationObserverAsWeakPtr
GetBoundNetLog
SetTotalBytes
OnAllDataSaved
MarkAsComplete
DestinationUpdate
DestinationError
DestinationCompleted
Init
Start
OnDownloadFileInitialized
OnDownloadTargetDetermined
OnDownloadRenamedToIntermediateName
MaybeCompleteDownload
OnDownloadCompleting
OnDownloadRenamedToFinalName
DelayedDownloadOpened
Completed
OnResumeRequestStarted
Interrupt
ReleaseDownloadFile
IsDownloadReadyForCompletion
TransitionTo
SetDangerType
SetFullPath
AutoResumeIfValid
ResumeInterruptedDownload
InternalToExternalState
ExternalToInternalState
DebugDownloadStateString
DebugResumeModeString
// Copyright (c) 2012 The Chromium Authors. All rights reserved.
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.

// File method ordering: Methods in this file are in the same order as
// in download_item_impl.h, with the following exception: The public
// interface Start is placed in chronological order with the other
// (private) routines that together define a DownloadItem's state
// transitions as the download progresses.  See "Download progression
// cascade" later in this file.

// A regular DownloadItem (created for a download in this session of the
// browser) normally goes through the following states:
//      * Created (when download starts)
//      * Destination filename determined
//      * Entered into the history database.
//      * Made visible in the download shelf.
//      * All the data is saved.  Note that the actual data download occurs
//        in parallel with the above steps, but until those steps are
//        complete, the state of the data save will be ignored.
//      * Download file is renamed to its final name, and possibly
//        auto-opened.

#include "content/browser/download/download_item_impl.h"

#include <vector>

#include "base/basictypes.h"
#include "base/bind.h"
#include "base/command_line.h"
#include "base/file_util.h"
#include "base/format_macros.h"
#include "base/logging.h"
#include "base/metrics/histogram.h"
#include "base/stl_util.h"
#include "base/strings/stringprintf.h"
#include "base/strings/utf_string_conversions.h"
#include "content/browser/download/download_create_info.h"
#include "content/browser/download/download_file.h"
#include "content/browser/download/download_interrupt_reasons_impl.h"
#include "content/browser/download/download_item_impl_delegate.h"
#include "content/browser/download/download_request_handle.h"
#include "content/browser/download/download_stats.h"
#include "content/browser/renderer_host/render_view_host_impl.h"
#include "content/browser/web_contents/web_contents_impl.h"
#include "content/public/browser/browser_context.h"
#include "content/public/browser/browser_thread.h"
#include "content/public/browser/content_browser_client.h"
#include "content/public/browser/download_danger_type.h"
#include "content/public/browser/download_interrupt_reasons.h"
#include "content/public/browser/download_url_parameters.h"
#include "content/public/common/content_switches.h"
#include "content/public/common/referrer.h"
#include "net/base/net_util.h"

namespace content {

namespace {

bool DeleteDownloadedFile(const base::FilePath& path) {
  DCHECK(BrowserThread::CurrentlyOn(BrowserThread::FILE));

  // Make sure we only delete files.
  if (base::DirectoryExists(path))
    return true;
  return base::DeleteFile(path, false);
}

void DeleteDownloadedFileDone(
    base::WeakPtr<DownloadItemImpl> item,
    const base::Callback<void(bool)>& callback,
    bool success) {
  DCHECK(BrowserThread::CurrentlyOn(BrowserThread::UI));
  if (success && item.get())
    item->OnDownloadedFileRemoved();
  callback.Run(success);
}

// Wrapper around DownloadFile::Detach and DownloadFile::Cancel that
// takes ownership of the DownloadFile and hence implicitly destroys it
// at the end of the function.
static base::FilePath DownloadFileDetach(
    scoped_ptr<DownloadFile> download_file) {
  DCHECK(BrowserThread::CurrentlyOn(BrowserThread::FILE));
  base::FilePath full_path = download_file->FullPath();
  download_file->Detach();
  return full_path;
}

static void DownloadFileCancel(scoped_ptr<DownloadFile> download_file) {
  DCHECK(BrowserThread::CurrentlyOn(BrowserThread::FILE));
  download_file->Cancel();
}

bool IsDownloadResumptionEnabled() {
  return CommandLine::ForCurrentProcess()->HasSwitch(
      switches::kEnableDownloadResumption);
}

}  // namespace

const uint32 DownloadItem::kInvalidId = 0;

const char DownloadItem::kEmptyFileHash[] = "";

// The maximum number of attempts we will make to resume automatically.
const int DownloadItemImpl::kMaxAutoResumeAttempts = 5;

// Constructor for reading from the history service.
DownloadItemImpl::DownloadItemImpl(DownloadItemImplDelegate* delegate,
                                   uint32 download_id,
                                   const base::FilePath& current_path,
                                   const base::FilePath& target_path,
                                   const std::vector<GURL>& url_chain,
                                   const GURL& referrer_url,
                                   const base::Time& start_time,
                                   const base::Time& end_time,
                                   const std::string& etag,
                                   const std::string& last_modified,
                                   int64 received_bytes,
                                   int64 total_bytes,
                                   DownloadItem::DownloadState state,
                                   DownloadDangerType danger_type,
                                   DownloadInterruptReason interrupt_reason,
                                   bool opened,
                                   const net::BoundNetLog& bound_net_log)
    : is_save_package_download_(false),
      download_id_(download_id),
      current_path_(current_path),
      target_path_(target_path),
      target_disposition_(TARGET_DISPOSITION_OVERWRITE),
      url_chain_(url_chain),
      referrer_url_(referrer_url),
      transition_type_(PAGE_TRANSITION_LINK),
      has_user_gesture_(false),
      total_bytes_(total_bytes),
      received_bytes_(received_bytes),
      bytes_per_sec_(0),
      last_modified_time_(last_modified),
      etag_(etag),
      last_reason_(interrupt_reason),
      start_tick_(base::TimeTicks()),
      state_(ExternalToInternalState(state)),
      danger_type_(danger_type),
      start_time_(start_time),
      end_time_(end_time),
      delegate_(delegate),
      is_paused_(false),
      auto_resume_count_(0),
      open_when_complete_(false),
      file_externally_removed_(false),
      auto_opened_(false),
      is_temporary_(false),
      all_data_saved_(state == COMPLETE),
      destination_error_(content::DOWNLOAD_INTERRUPT_REASON_NONE),
      opened_(opened),
      delegate_delayed_complete_(false),
      bound_net_log_(bound_net_log),
      weak_ptr_factory_(this) {
  delegate_->Attach();
  DCHECK_NE(IN_PROGRESS_INTERNAL, state_);
  Init(false /* not actively downloading */, SRC_HISTORY_IMPORT);
}

// Constructing for a regular download:
DownloadItemImpl::DownloadItemImpl(
    DownloadItemImplDelegate* delegate,
    uint32 download_id,
    const DownloadCreateInfo& info,
    const net::BoundNetLog& bound_net_log)
    : is_save_package_download_(false),
      download_id_(download_id),
      target_disposition_(
          (info.save_info->prompt_for_save_location) ?
              TARGET_DISPOSITION_PROMPT : TARGET_DISPOSITION_OVERWRITE),
      url_chain_(info.url_chain),
      referrer_url_(info.referrer_url),
      tab_url_(info.tab_url),
      tab_referrer_url_(info.tab_referrer_url),
      suggested_filename_(base::UTF16ToUTF8(info.save_info->suggested_name)),
      forced_file_path_(info.save_info->file_path),
      transition_type_(info.transition_type),
      has_user_gesture_(info.has_user_gesture),
      content_disposition_(info.content_disposition),
      mime_type_(info.mime_type),
      original_mime_type_(info.original_mime_type),
      remote_address_(info.remote_address),
      total_bytes_(info.total_bytes),
      received_bytes_(0),
      bytes_per_sec_(0),
      last_modified_time_(info.last_modified),
      etag_(info.etag),
      last_reason_(DOWNLOAD_INTERRUPT_REASON_NONE),
      start_tick_(base::TimeTicks::Now()),
      state_(IN_PROGRESS_INTERNAL),
      danger_type_(DOWNLOAD_DANGER_TYPE_NOT_DANGEROUS),
      start_time_(info.start_time),
      delegate_(delegate),
      is_paused_(false),
      auto_resume_count_(0),
      open_when_complete_(false),
      file_externally_removed_(false),
      auto_opened_(false),
      is_temporary_(!info.save_info->file_path.empty()),
      all_data_saved_(false),
      destination_error_(content::DOWNLOAD_INTERRUPT_REASON_NONE),
      opened_(false),
      delegate_delayed_complete_(false),
      bound_net_log_(bound_net_log),
      weak_ptr_factory_(this) {
  delegate_->Attach();
  Init(true /* actively downloading */, SRC_ACTIVE_DOWNLOAD);

  // Link the event sources.
  bound_net_log_.AddEvent(
      net::NetLog::TYPE_DOWNLOAD_URL_REQUEST,
      info.request_bound_net_log.source().ToEventParametersCallback());

  info.request_bound_net_log.AddEvent(
      net::NetLog::TYPE_DOWNLOAD_STARTED,
      bound_net_log_.source().ToEventParametersCallback());
}

// Constructing for the "Save Page As..." feature:
DownloadItemImpl::DownloadItemImpl(
    DownloadItemImplDelegate* delegate,
    uint32 download_id,
    const base::FilePath& path,
    const GURL& url,
    const std::string& mime_type,
    scoped_ptr<DownloadRequestHandleInterface> request_handle,
    const net::BoundNetLog& bound_net_log)
    : is_save_package_download_(true),
      request_handle_(request_handle.Pass()),
      download_id_(download_id),
      current_path_(path),
      target_path_(path),
      target_disposition_(TARGET_DISPOSITION_OVERWRITE),
      url_chain_(1, url),
      referrer_url_(GURL()),
      transition_type_(PAGE_TRANSITION_LINK),
      has_user_gesture_(false),
      mime_type_(mime_type),
      original_mime_type_(mime_type),
      total_bytes_(0),
      received_bytes_(0),
      bytes_per_sec_(0),
      last_reason_(DOWNLOAD_INTERRUPT_REASON_NONE),
      start_tick_(base::TimeTicks::Now()),
      state_(IN_PROGRESS_INTERNAL),
      danger_type_(DOWNLOAD_DANGER_TYPE_NOT_DANGEROUS),
      start_time_(base::Time::Now()),
      delegate_(delegate),
      is_paused_(false),
      auto_resume_count_(0),
      open_when_complete_(false),
      file_externally_removed_(false),
      auto_opened_(false),
      is_temporary_(false),
      all_data_saved_(false),
      destination_error_(content::DOWNLOAD_INTERRUPT_REASON_NONE),
      opened_(false),
      delegate_delayed_complete_(false),
      bound_net_log_(bound_net_log),
      weak_ptr_factory_(this) {
  delegate_->Attach();
  Init(true /* actively downloading */, SRC_SAVE_PAGE_AS);
}

DownloadItemImpl::~DownloadItemImpl() {
  DCHECK(BrowserThread::CurrentlyOn(BrowserThread::UI));

  // Should always have been nuked before now, at worst in
  // DownloadManager shutdown.
  DCHECK(!download_file_.get());

  FOR_EACH_OBSERVER(Observer, observers_, OnDownloadDestroyed(this));
  delegate_->AssertStateConsistent(this);
  delegate_->Detach();
}

void DownloadItemImpl::AddObserver(Observer* observer) {
  DCHECK(BrowserThread::CurrentlyOn(BrowserThread::UI));

  observers_.AddObserver(observer);
}

void DownloadItemImpl::RemoveObserver(Observer* observer) {
  DCHECK(BrowserThread::CurrentlyOn(BrowserThread::UI));

  observers_.RemoveObserver(observer);
}

void DownloadItemImpl::UpdateObservers() {
  DCHECK(BrowserThread::CurrentlyOn(BrowserThread::UI));

  FOR_EACH_OBSERVER(Observer, observers_, OnDownloadUpdated(this));
}

void DownloadItemImpl::ValidateDangerousDownload() {
  DCHECK(BrowserThread::CurrentlyOn(BrowserThread::UI));
  DCHECK(!IsDone());
  DCHECK(IsDangerous());

  VLOG(20) << __FUNCTION__ << " download=" << DebugString(true);

  if (IsDone() || !IsDangerous())
    return;

  RecordDangerousDownloadAccept(GetDangerType(),
                                GetTargetFilePath());

  danger_type_ = DOWNLOAD_DANGER_TYPE_USER_VALIDATED;

  bound_net_log_.AddEvent(
      net::NetLog::TYPE_DOWNLOAD_ITEM_SAFETY_STATE_UPDATED,
      base::Bind(&ItemCheckedNetLogCallback, GetDangerType()));

  UpdateObservers();

  MaybeCompleteDownload();
}

void DownloadItemImpl::StealDangerousDownload(
    const AcquireFileCallback& callback) {
  VLOG(20) << __FUNCTION__ << "() download = " << DebugString(true);
  DCHECK(BrowserThread::CurrentlyOn(BrowserThread::UI));
  DCHECK(IsDangerous());
  if (download_file_) {
    BrowserThread::PostTaskAndReplyWithResult(
        BrowserThread::FILE,
        FROM_HERE,
        base::Bind(&DownloadFileDetach, base::Passed(&download_file_)),
        callback);
  } else {
    callback.Run(current_path_);
  }
  current_path_.clear();
  Remove();
  // We have now been deleted.
}

void DownloadItemImpl::Pause() {
  DCHECK(BrowserThread::CurrentlyOn(BrowserThread::UI));

  // Ignore irrelevant states.
  if (state_ != IN_PROGRESS_INTERNAL || is_paused_)
    return;

  request_handle_->PauseRequest();
  is_paused_ = true;
  UpdateObservers();
}

void DownloadItemImpl::Resume() {
  DCHECK(BrowserThread::CurrentlyOn(BrowserThread::UI));
  switch (state_) {
    case IN_PROGRESS_INTERNAL:
      if (!is_paused_)
        return;
      request_handle_->ResumeRequest();
      is_paused_ = false;
      UpdateObservers();
      return;

    case COMPLETING_INTERNAL:
    case COMPLETE_INTERNAL:
    case CANCELLED_INTERNAL:
    case RESUMING_INTERNAL:
      return;

    case INTERRUPTED_INTERNAL:
      auto_resume_count_ = 0;  // User input resets the counter.
      ResumeInterruptedDownload();
      return;

    case MAX_DOWNLOAD_INTERNAL_STATE:
      NOTREACHED();
  }
}

void DownloadItemImpl::Cancel(bool user_cancel) {
  DCHECK(BrowserThread::CurrentlyOn(BrowserThread::UI));

  VLOG(20) << __FUNCTION__ << "() download = " << DebugString(true);
  if (state_ != IN_PROGRESS_INTERNAL &&
      state_ != INTERRUPTED_INTERNAL &&
      state_ != RESUMING_INTERNAL) {
    // Small downloads might be complete before this method has a chance to run.
    return;
  }

  if (IsDangerous()) {
    RecordDangerousDownloadDiscard(
        user_cancel ? DOWNLOAD_DISCARD_DUE_TO_USER_ACTION
                    : DOWNLOAD_DISCARD_DUE_TO_SHUTDOWN,
        GetDangerType(),
        GetTargetFilePath());
  }

  last_reason_ = user_cancel ? DOWNLOAD_INTERRUPT_REASON_USER_CANCELED
                             : DOWNLOAD_INTERRUPT_REASON_USER_SHUTDOWN;

  RecordDownloadCount(CANCELLED_COUNT);

  // TODO(rdsmith/benjhayden): Remove condition as part of
  // |SavePackage| integration.
  // |download_file_| can be NULL if Interrupt() is called after the
  // download file has been released.
  if (!is_save_package_download_ && download_file_)
    ReleaseDownloadFile(true);

  if (state_ == IN_PROGRESS_INTERNAL) {
    // Cancel the originating URL request unless it's already been cancelled
    // by interrupt.
    request_handle_->CancelRequest();
  }

  // Remove the intermediate file if we are cancelling an interrupted download.
  // Continuable interruptions leave the intermediate file around.
  if ((state_ == INTERRUPTED_INTERNAL || state_ == RESUMING_INTERNAL) &&
      !current_path_.empty()) {
    BrowserThread::PostTask(
        BrowserThread::FILE, FROM_HERE,
        base::Bind(base::IgnoreResult(&DeleteDownloadedFile), current_path_));
    current_path_.clear();
  }

  TransitionTo(CANCELLED_INTERNAL, UPDATE_OBSERVERS);
}

void DownloadItemImpl::Remove() {
  VLOG(20) << __FUNCTION__ << "() download = " << DebugString(true);
  DCHECK(BrowserThread::CurrentlyOn(BrowserThread::UI));

  delegate_->AssertStateConsistent(this);
  Cancel(true);
  delegate_->AssertStateConsistent(this);

  NotifyRemoved();
  delegate_->DownloadRemoved(this);
  // We have now been deleted.
}

void DownloadItemImpl::OpenDownload() {
  DCHECK(BrowserThread::CurrentlyOn(BrowserThread::UI));

  if (!IsDone()) {
    // We don't honor the open_when_complete_ flag for temporary
    // downloads. Don't set it because it shows up in the UI.
    if (!IsTemporary())
      open_when_complete_ = !open_when_complete_;
    return;
  }

  if (state_ != COMPLETE_INTERNAL || file_externally_removed_)
    return;

  // Ideally, we want to detect errors in opening and report them, but we
  // don't generally have the proper interface for that to the external
  // program that opens the file.  So instead we spawn a check to update
  // the UI if the file has been deleted in parallel with the open.
  delegate_->CheckForFileRemoval(this);
  RecordOpen(GetEndTime(), !GetOpened());
  opened_ = true;
  FOR_EACH_OBSERVER(Observer, observers_, OnDownloadOpened(this));
  delegate_->OpenDownload(this);
}

void DownloadItemImpl::ShowDownloadInShell() {
  DCHECK(BrowserThread::CurrentlyOn(BrowserThread::UI));

  delegate_->ShowDownloadInShell(this);
}

uint32 DownloadItemImpl::GetId() const {
  return download_id_;
}

DownloadItem::DownloadState DownloadItemImpl::GetState() const {
  return InternalToExternalState(state_);
}

DownloadInterruptReason DownloadItemImpl::GetLastReason() const {
  return last_reason_;
}

bool DownloadItemImpl::IsPaused() const {
  return is_paused_;
}

bool DownloadItemImpl::IsTemporary() const {
  return is_temporary_;
}

bool DownloadItemImpl::CanResume() const {
  if ((GetState() == IN_PROGRESS) && IsPaused())
    return true;

  if (state_ != INTERRUPTED_INTERNAL)
    return false;

  // Downloads that don't have a WebContents should still be resumable, but this
  // isn't currently the case. See ResumeInterruptedDownload().
  if (!GetWebContents())
    return false;

  ResumeMode resume_mode = GetResumeMode();
  return IsDownloadResumptionEnabled() &&
      (resume_mode == RESUME_MODE_USER_RESTART ||
       resume_mode == RESUME_MODE_USER_CONTINUE);
}

bool DownloadItemImpl::IsDone() const {
  switch (state_) {
    case IN_PROGRESS_INTERNAL:
    case COMPLETING_INTERNAL:
      return false;

    case COMPLETE_INTERNAL:
    case CANCELLED_INTERNAL:
      return true;

    case INTERRUPTED_INTERNAL:
      return !CanResume();

    case RESUMING_INTERNAL:
      return false;

    case MAX_DOWNLOAD_INTERNAL_STATE:
      break;
  }
  NOTREACHED();
  return true;
}

const GURL& DownloadItemImpl::GetURL() const {
  return url_chain_.empty() ? GURL::EmptyGURL() : url_chain_.back();
}

const std::vector<GURL>& DownloadItemImpl::GetUrlChain() const {
  return url_chain_;
}

const GURL& DownloadItemImpl::GetOriginalUrl() const {
  // Be careful about taking the front() of possibly-empty vectors!
  // http://crbug.com/190096
  return url_chain_.empty() ? GURL::EmptyGURL() : url_chain_.front();
}

const GURL& DownloadItemImpl::GetReferrerUrl() const {
  return referrer_url_;
}

const GURL& DownloadItemImpl::GetTabUrl() const {
  return tab_url_;
}

const GURL& DownloadItemImpl::GetTabReferrerUrl() const {
  return tab_referrer_url_;
}

std::string DownloadItemImpl::GetSuggestedFilename() const {
  return suggested_filename_;
}

std::string DownloadItemImpl::GetContentDisposition() const {
  return content_disposition_;
}

std::string DownloadItemImpl::GetMimeType() const {
  return mime_type_;
}

std::string DownloadItemImpl::GetOriginalMimeType() const {
  return original_mime_type_;
}

std::string DownloadItemImpl::GetRemoteAddress() const {
  return remote_address_;
}

bool DownloadItemImpl::HasUserGesture() const {
  return has_user_gesture_;
};

PageTransition DownloadItemImpl::GetTransitionType() const {
  return transition_type_;
};

const std::string& DownloadItemImpl::GetLastModifiedTime() const {
  return last_modified_time_;
}

const std::string& DownloadItemImpl::GetETag() const {
  return etag_;
}

bool DownloadItemImpl::IsSavePackageDownload() const {
  return is_save_package_download_;
}

const base::FilePath& DownloadItemImpl::GetFullPath() const {
  return current_path_;
}

const base::FilePath& DownloadItemImpl::GetTargetFilePath() const {
  return target_path_;
}

const base::FilePath& DownloadItemImpl::GetForcedFilePath() const {
  // TODO(asanka): Get rid of GetForcedFilePath(). We should instead just
  // require that clients respect GetTargetFilePath() if it is already set.
  return forced_file_path_;
}

base::FilePath DownloadItemImpl::GetFileNameToReportUser() const {
  if (!display_name_.empty())
    return display_name_;
  return target_path_.BaseName();
}

DownloadItem::TargetDisposition DownloadItemImpl::GetTargetDisposition() const {
  return target_disposition_;
}

const std::string& DownloadItemImpl::GetHash() const {
  return hash_;
}

const std::string& DownloadItemImpl::GetHashState() const {
  return hash_state_;
}

bool DownloadItemImpl::GetFileExternallyRemoved() const {
  return file_externally_removed_;
}

void DownloadItemImpl::DeleteFile(const base::Callback<void(bool)>& callback) {
  DCHECK(BrowserThread::CurrentlyOn(BrowserThread::UI));
  if (GetState() != DownloadItem::COMPLETE) {
    // Pass a null WeakPtr so it doesn't call OnDownloadedFileRemoved.
    BrowserThread::PostTask(
        BrowserThread::UI, FROM_HERE,
        base::Bind(&DeleteDownloadedFileDone,
                   base::WeakPtr<DownloadItemImpl>(), callback, false));
    return;
  }
  if (current_path_.empty() || file_externally_removed_) {
    // Pass a null WeakPtr so it doesn't call OnDownloadedFileRemoved.
    BrowserThread::PostTask(
        BrowserThread::UI, FROM_HERE,
        base::Bind(&DeleteDownloadedFileDone,
                   base::WeakPtr<DownloadItemImpl>(), callback, true));
    return;
  }
  BrowserThread::PostTaskAndReplyWithResult(
      BrowserThread::FILE, FROM_HERE,
      base::Bind(&DeleteDownloadedFile, current_path_),
      base::Bind(&DeleteDownloadedFileDone,
                 weak_ptr_factory_.GetWeakPtr(), callback));
}

bool DownloadItemImpl::IsDangerous() const {
#if defined(OS_WIN)
  // TODO(noelutz): At this point only the windows views UI supports
  // warnings based on dangerous content.
  return (danger_type_ == DOWNLOAD_DANGER_TYPE_DANGEROUS_FILE ||
          danger_type_ == DOWNLOAD_DANGER_TYPE_DANGEROUS_URL ||
          danger_type_ == DOWNLOAD_DANGER_TYPE_DANGEROUS_CONTENT ||
          danger_type_ == DOWNLOAD_DANGER_TYPE_UNCOMMON_CONTENT ||
          danger_type_ == DOWNLOAD_DANGER_TYPE_DANGEROUS_HOST ||
          danger_type_ == DOWNLOAD_DANGER_TYPE_POTENTIALLY_UNWANTED);
#else
  return (danger_type_ == DOWNLOAD_DANGER_TYPE_DANGEROUS_FILE ||
          danger_type_ == DOWNLOAD_DANGER_TYPE_DANGEROUS_URL);
#endif
}

DownloadDangerType DownloadItemImpl::GetDangerType() const {
  return danger_type_;
}

bool DownloadItemImpl::TimeRemaining(base::TimeDelta* remaining) const {
  if (total_bytes_ <= 0)
    return false;  // We never received the content_length for this download.

  int64 speed = CurrentSpeed();
  if (speed == 0)
    return false;

  *remaining = base::TimeDelta::FromSeconds(
      (total_bytes_ - received_bytes_) / speed);
  return true;
}

int64 DownloadItemImpl::CurrentSpeed() const {
  if (is_paused_)
    return 0;
  return bytes_per_sec_;
}

int DownloadItemImpl::PercentComplete() const {
  // If the delegate is delaying completion of the download, then we have no
  // idea how long it will take.
  if (delegate_delayed_complete_ || total_bytes_ <= 0)
    return -1;

  return static_cast<int>(received_bytes_ * 100.0 / total_bytes_);
}

bool DownloadItemImpl::AllDataSaved() const {
  return all_data_saved_;
}

int64 DownloadItemImpl::GetTotalBytes() const {
  return total_bytes_;
}

int64 DownloadItemImpl::GetReceivedBytes() const {
  return received_bytes_;
}

base::Time DownloadItemImpl::GetStartTime() const {
  return start_time_;
}

base::Time DownloadItemImpl::GetEndTime() const {
  return end_time_;
}

bool DownloadItemImpl::CanShowInFolder() {
  // A download can be shown in the folder if the downloaded file is in a known
  // location.
  return CanOpenDownload() && !GetFullPath().empty();
}

bool DownloadItemImpl::CanOpenDownload() {
  // We can open the file or mark it for opening on completion if the download
  // is expected to complete successfully. Exclude temporary downloads, since
  // they aren't owned by the download system.
  const bool is_complete = GetState() == DownloadItem::COMPLETE;
  return (!IsDone() || is_complete) && !IsTemporary() &&
         !file_externally_removed_;
}

bool DownloadItemImpl::ShouldOpenFileBasedOnExtension() {
  return delegate_->ShouldOpenFileBasedOnExtension(GetTargetFilePath());
}

bool DownloadItemImpl::GetOpenWhenComplete() const {
  return open_when_complete_;
}

bool DownloadItemImpl::GetAutoOpened() {
  return auto_opened_;
}

bool DownloadItemImpl::GetOpened() const {
  return opened_;
}

BrowserContext* DownloadItemImpl::GetBrowserContext() const {
  return delegate_->GetBrowserContext();
}

WebContents* DownloadItemImpl::GetWebContents() const {
  // TODO(rdsmith): Remove null check after removing GetWebContents() from
  // paths that might be used by DownloadItems created from history import.
  // Currently such items have null request_handle_s, where other items
  // (regular and SavePackage downloads) have actual objects off the pointer.
  if (request_handle_)
    return request_handle_->GetWebContents();
  return NULL;
}

void DownloadItemImpl::OnContentCheckCompleted(DownloadDangerType danger_type) {
  DCHECK(BrowserThread::CurrentlyOn(BrowserThread::UI));
  DCHECK(AllDataSaved());
  VLOG(20) << __FUNCTION__ << " danger_type=" << danger_type
           << " download=" << DebugString(true);
  SetDangerType(danger_type);
  UpdateObservers();
}

void DownloadItemImpl::SetOpenWhenComplete(bool open) {
  open_when_complete_ = open;
}

void DownloadItemImpl::SetIsTemporary(bool temporary) {
  is_temporary_ = temporary;
}

void DownloadItemImpl::SetOpened(bool opened) {
  opened_ = opened;
}

void DownloadItemImpl::SetDisplayName(const base::FilePath& name) {
  display_name_ = name;
}

std::string DownloadItemImpl::DebugString(bool verbose) const {
  std::string description =
      base::StringPrintf("{ id = %d"
                         " state = %s",
                         download_id_,
                         DebugDownloadStateString(state_));

  // Construct a string of the URL chain.
  std::string url_list("<none>");
  if (!url_chain_.empty()) {
    std::vector<GURL>::const_iterator iter = url_chain_.begin();
    std::vector<GURL>::const_iterator last = url_chain_.end();
    url_list = (*iter).is_valid() ? (*iter).spec() : "<invalid>";
    ++iter;
    for ( ; verbose && (iter != last); ++iter) {
      url_list += " ->\n\t";
      const GURL& next_url = *iter;
      url_list += next_url.is_valid() ? next_url.spec() : "<invalid>";
    }
  }

  if (verbose) {
    description += base::StringPrintf(
        " total = %" PRId64
        " received = %" PRId64
        " reason = %s"
        " paused = %c"
        " resume_mode = %s"
        " auto_resume_count = %d"
        " danger = %d"
        " all_data_saved = %c"
        " last_modified = '%s'"
        " etag = '%s'"
        " has_download_file = %s"
        " url_chain = \n\t\"%s\"\n\t"
        " full_path = \"%" PRFilePath "\"\n\t"
        " target_path = \"%" PRFilePath "\"",
        GetTotalBytes(),
        GetReceivedBytes(),
        DownloadInterruptReasonToString(last_reason_).c_str(),
        IsPaused() ? 'T' : 'F',
        DebugResumeModeString(GetResumeMode()),
        auto_resume_count_,
        GetDangerType(),
        AllDataSaved() ? 'T' : 'F',
        GetLastModifiedTime().c_str(),
        GetETag().c_str(),
        download_file_.get() ? "true" : "false",
        url_list.c_str(),
        GetFullPath().value().c_str(),
        GetTargetFilePath().value().c_str());
  } else {
    description += base::StringPrintf(" url = \"%s\"", url_list.c_str());
  }

  description += " }";

  return description;
}

DownloadItemImpl::ResumeMode DownloadItemImpl::GetResumeMode() const {
  DCHECK(BrowserThread::CurrentlyOn(BrowserThread::UI));
  // We can't continue without a handle on the intermediate file.
  // We also can't continue if we don't have some verifier to make sure
  // we're getting the same file.
  const bool force_restart =
      (current_path_.empty() || (etag_.empty() && last_modified_time_.empty()));

  // We won't auto-restart if we've used up our attempts or the
  // download has been paused by user action.
  const bool force_user =
      (auto_resume_count_ >= kMaxAutoResumeAttempts || is_paused_);

  ResumeMode mode = RESUME_MODE_INVALID;

  switch(last_reason_) {
    case DOWNLOAD_INTERRUPT_REASON_FILE_TRANSIENT_ERROR:
    case DOWNLOAD_INTERRUPT_REASON_NETWORK_TIMEOUT:
      if (force_restart && force_user)
        mode = RESUME_MODE_USER_RESTART;
      else if (force_restart)
        mode = RESUME_MODE_IMMEDIATE_RESTART;
      else if (force_user)
        mode = RESUME_MODE_USER_CONTINUE;
      else
        mode = RESUME_MODE_IMMEDIATE_CONTINUE;
      break;

    case DOWNLOAD_INTERRUPT_REASON_SERVER_PRECONDITION:
    case DOWNLOAD_INTERRUPT_REASON_SERVER_NO_RANGE:
    case DOWNLOAD_INTERRUPT_REASON_FILE_TOO_SHORT:
      if (force_user)
        mode = RESUME_MODE_USER_RESTART;
      else
        mode = RESUME_MODE_IMMEDIATE_RESTART;
      break;

    case DOWNLOAD_INTERRUPT_REASON_NETWORK_FAILED:
    case DOWNLOAD_INTERRUPT_REASON_NETWORK_DISCONNECTED:
    case DOWNLOAD_INTERRUPT_REASON_NETWORK_SERVER_DOWN:
    case DOWNLOAD_INTERRUPT_REASON_NETWORK_INVALID_REQUEST:
    case DOWNLOAD_INTERRUPT_REASON_SERVER_FAILED:
    case DOWNLOAD_INTERRUPT_REASON_USER_SHUTDOWN:
    case DOWNLOAD_INTERRUPT_REASON_CRASH:
      if (force_restart)
        mode = RESUME_MODE_USER_RESTART;
      else
        mode = RESUME_MODE_USER_CONTINUE;
      break;

    case DOWNLOAD_INTERRUPT_REASON_FILE_FAILED:
    case DOWNLOAD_INTERRUPT_REASON_FILE_ACCESS_DENIED:
    case DOWNLOAD_INTERRUPT_REASON_FILE_NO_SPACE:
    case DOWNLOAD_INTERRUPT_REASON_FILE_NAME_TOO_LONG:
    case DOWNLOAD_INTERRUPT_REASON_FILE_TOO_LARGE:
      mode = RESUME_MODE_USER_RESTART;
      break;

    case DOWNLOAD_INTERRUPT_REASON_NONE:
    case DOWNLOAD_INTERRUPT_REASON_FILE_VIRUS_INFECTED:
    case DOWNLOAD_INTERRUPT_REASON_SERVER_BAD_CONTENT:
    case DOWNLOAD_INTERRUPT_REASON_USER_CANCELED:
    case DOWNLOAD_INTERRUPT_REASON_FILE_BLOCKED:
    case DOWNLOAD_INTERRUPT_REASON_FILE_SECURITY_CHECK_FAILED:
      mode = RESUME_MODE_INVALID;
      break;
  }

  return mode;
}

void DownloadItemImpl::MergeOriginInfoOnResume(
    const DownloadCreateInfo& new_create_info) {
  DCHECK(BrowserThread::CurrentlyOn(BrowserThread::UI));
  DCHECK_EQ(RESUMING_INTERNAL, state_);
  DCHECK(!new_create_info.url_chain.empty());

  // We are going to tack on any new redirects to our list of redirects.
  // When a download is resumed, the URL used for the resumption request is the
  // one at the end of the previous redirect chain. Tacking additional redirects
  // to the end of this chain ensures that:
  // - If the download needs to be resumed again, the ETag/Last-Modified headers
  //   will be used with the last server that sent them to us.
  // - The redirect chain contains all the servers that were involved in this
  //   download since the initial request, in order.
  std::vector<GURL>::const_iterator chain_iter =
      new_create_info.url_chain.begin();
  if (*chain_iter == url_chain_.back())
    ++chain_iter;

  // Record some stats. If the precondition failed (the server returned
  // HTTP_PRECONDITION_FAILED), then the download will automatically retried as
  // a full request rather than a partial. Full restarts clobber validators.
  int origin_state = 0;
  if (chain_iter != new_create_info.url_chain.end())
    origin_state |= ORIGIN_STATE_ON_RESUMPTION_ADDITIONAL_REDIRECTS;
  if (etag_ != new_create_info.etag ||
      last_modified_time_ != new_create_info.last_modified)
    origin_state |= ORIGIN_STATE_ON_RESUMPTION_VALIDATORS_CHANGED;
  if (content_disposition_ != new_create_info.content_disposition)
    origin_state |= ORIGIN_STATE_ON_RESUMPTION_CONTENT_DISPOSITION_CHANGED;
  RecordOriginStateOnResumption(new_create_info.save_info->offset != 0,
                                origin_state);

  url_chain_.insert(
      url_chain_.end(), chain_iter, new_create_info.url_chain.end());
  etag_ = new_create_info.etag;
  last_modified_time_ = new_create_info.last_modified;
  content_disposition_ = new_create_info.content_disposition;

  // Don't update observers. This method is expected to be called just before a
  // DownloadFile is created and Start() is called. The observers will be
  // notified when the download transitions to the IN_PROGRESS state.
}

void DownloadItemImpl::NotifyRemoved() {
  FOR_EACH_OBSERVER(Observer, observers_, OnDownloadRemoved(this));
}

void DownloadItemImpl::OnDownloadedFileRemoved() {
  file_externally_removed_ = true;
  VLOG(20) << __FUNCTION__ << " download=" << DebugString(true);
  UpdateObservers();
}

base::WeakPtr<DownloadDestinationObserver>
DownloadItemImpl::DestinationObserverAsWeakPtr() {
  return weak_ptr_factory_.GetWeakPtr();
}

const net::BoundNetLog& DownloadItemImpl::GetBoundNetLog() const {
  return bound_net_log_;
}

void DownloadItemImpl::SetTotalBytes(int64 total_bytes) {
  total_bytes_ = total_bytes;
}

void DownloadItemImpl::OnAllDataSaved(const std::string& final_hash) {
  DCHECK(BrowserThread::CurrentlyOn(BrowserThread::UI));

  DCHECK_EQ(IN_PROGRESS_INTERNAL, state_);
  DCHECK(!all_data_saved_);
  all_data_saved_ = true;
  VLOG(20) << __FUNCTION__ << " download=" << DebugString(true);

  // Store final hash and null out intermediate serialized hash state.
  hash_ = final_hash;
  hash_state_ = "";

  UpdateObservers();
}

void DownloadItemImpl::MarkAsComplete() {
  DCHECK(BrowserThread::CurrentlyOn(BrowserThread::UI));

  DCHECK(all_data_saved_);
  end_time_ = base::Time::Now();
  TransitionTo(COMPLETE_INTERNAL, UPDATE_OBSERVERS);
}

void DownloadItemImpl::DestinationUpdate(int64 bytes_so_far,
                                         int64 bytes_per_sec,
                                         const std::string& hash_state) {
  DCHECK(BrowserThread::CurrentlyOn(BrowserThread::UI));
  VLOG(20) << __FUNCTION__ << " so_far=" << bytes_so_far
           << " per_sec=" << bytes_per_sec << " download=" << DebugString(true);

  if (GetState() != IN_PROGRESS) {
    // Ignore if we're no longer in-progress.  This can happen if we race a
    // Cancel on the UI thread with an update on the FILE thread.
    //
    // TODO(rdsmith): Arguably we should let this go through, as this means
    // the download really did get further than we know before it was
    // cancelled.  But the gain isn't very large, and the code is more
    // fragile if it has to support in progress updates in a non-in-progress
    // state.  This issue should be readdressed when we revamp performance
    // reporting.
    return;
  }
  bytes_per_sec_ = bytes_per_sec;
  hash_state_ = hash_state;
  received_bytes_ = bytes_so_far;

  // If we've received more data than we were expecting (bad server info?),
  // revert to 'unknown size mode'.
  if (received_bytes_ > total_bytes_)
    total_bytes_ = 0;

  if (bound_net_log_.IsLogging()) {
    bound_net_log_.AddEvent(
        net::NetLog::TYPE_DOWNLOAD_ITEM_UPDATED,
        net::NetLog::Int64Callback("bytes_so_far", received_bytes_));
  }

  UpdateObservers();
}

void DownloadItemImpl::DestinationError(DownloadInterruptReason reason) {
  // Postpone recognition of this error until after file name determination
  // has completed and the intermediate file has been renamed to simplify
  // resumption conditions.
  if (current_path_.empty() || target_path_.empty())
    destination_error_ = reason;
  else
    Interrupt(reason);
}

void DownloadItemImpl::DestinationCompleted(const std::string& final_hash) {
  VLOG(20) << __FUNCTION__ << " download=" << DebugString(true);
  if (GetState() != IN_PROGRESS)
    return;
  OnAllDataSaved(final_hash);
  MaybeCompleteDownload();
}

// **** Download progression cascade

void DownloadItemImpl::Init(bool active,
                            DownloadType download_type) {
  DCHECK(BrowserThread::CurrentlyOn(BrowserThread::UI));

  if (active)
    RecordDownloadCount(START_COUNT);

  std::string file_name;
  if (download_type == SRC_HISTORY_IMPORT) {
    // target_path_ works for History and Save As versions.
    file_name = target_path_.AsUTF8Unsafe();
  } else {
    // See if it's set programmatically.
    file_name = forced_file_path_.AsUTF8Unsafe();
    // Possibly has a 'download' attribute for the anchor.
    if (file_name.empty())
      file_name = suggested_filename_;
    // From the URL file name.
    if (file_name.empty())
      file_name = GetURL().ExtractFileName();
  }

  base::Callback<base::Value*(net::NetLog::LogLevel)> active_data = base::Bind(
      &ItemActivatedNetLogCallback, this, download_type, &file_name);
  if (active) {
    bound_net_log_.BeginEvent(
        net::NetLog::TYPE_DOWNLOAD_ITEM_ACTIVE, active_data);
  } else {
    bound_net_log_.AddEvent(
        net::NetLog::TYPE_DOWNLOAD_ITEM_ACTIVE, active_data);
  }

  VLOG(20) << __FUNCTION__ << "() " << DebugString(true);
}

// We're starting the download.
void DownloadItemImpl::Start(
    scoped_ptr<DownloadFile> file,
    scoped_ptr<DownloadRequestHandleInterface> req_handle) {
  DCHECK(BrowserThread::CurrentlyOn(BrowserThread::UI));
  DCHECK(!download_file_.get());
  DCHECK(file.get());
  DCHECK(req_handle.get());

  download_file_ = file.Pass();
  request_handle_ = req_handle.Pass();

  if (GetState() == CANCELLED) {
    // The download was in the process of resuming when it was cancelled. Don't
    // proceed.
    ReleaseDownloadFile(true);
    request_handle_->CancelRequest();
    return;
  }

  TransitionTo(IN_PROGRESS_INTERNAL, UPDATE_OBSERVERS);

  BrowserThread::PostTask(
      BrowserThread::FILE, FROM_HERE,
      base::Bind(&DownloadFile::Initialize,
                 // Safe because we control download file lifetime.
                 base::Unretained(download_file_.get()),
                 base::Bind(&DownloadItemImpl::OnDownloadFileInitialized,
                            weak_ptr_factory_.GetWeakPtr())));
}

void DownloadItemImpl::OnDownloadFileInitialized(
    DownloadInterruptReason result) {
  DCHECK(BrowserThread::CurrentlyOn(BrowserThread::UI));
  if (result != DOWNLOAD_INTERRUPT_REASON_NONE) {
    Interrupt(result);
    // TODO(rdsmith/asanka): Arguably we should show this in the UI, but
    // it's not at all clear what to show--we haven't done filename
    // determination, so we don't know what name to display.  OTOH,
    // the failure mode of not showing the DI if the file initialization
    // fails isn't a good one.  Can we hack up a name based on the
    // URLRequest?  We'll need to make sure that initialization happens
    // properly.  Possibly the right thing is to have the UI handle
    // this case specially.
    return;
  }

  delegate_->DetermineDownloadTarget(
      this, base::Bind(&DownloadItemImpl::OnDownloadTargetDetermined,
                       weak_ptr_factory_.GetWeakPtr()));
}

// Called by delegate_ when the download target path has been
// determined.
void DownloadItemImpl::OnDownloadTargetDetermined(
    const base::FilePath& target_path,
    TargetDisposition disposition,
    DownloadDangerType danger_type,
    const base::FilePath& intermediate_path) {
  DCHECK(BrowserThread::CurrentlyOn(BrowserThread::UI));

  // If the |target_path| is empty, then we consider this download to be
  // canceled.
  if (target_path.empty()) {
    Cancel(true);
    return;
  }

  // TODO(rdsmith,asanka): We are ignoring the possibility that the download
  // has been interrupted at this point until we finish the intermediate
  // rename and set the full path.  That's dangerous, because we might race
  // with resumption, either manual (because the interrupt is visible to the
  // UI) or automatic.  If we keep the "ignore an error on download until file
  // name determination complete" semantics, we need to make sure that the
  // error is kept completely invisible until that point.

  VLOG(20) << __FUNCTION__ << " " << target_path.value() << " " << disposition
           << " " << danger_type << " " << DebugString(true);

  target_path_ = target_path;
  target_disposition_ = disposition;
  SetDangerType(danger_type);

  // We want the intermediate and target paths to refer to the same directory so
  // that they are both on the same device and subject to same
  // space/permission/availability constraints.
  DCHECK(intermediate_path.DirName() == target_path.DirName());

  // During resumption, we may choose to proceed with the same intermediate
  // file. No rename is necessary if our intermediate file already has the
  // correct name.
  //
  // The intermediate name may change from its original value during filename
  // determination on resumption, for example if the reason for the interruption
  // was the download target running out space, resulting in a user prompt.
  if (intermediate_path == current_path_) {
    OnDownloadRenamedToIntermediateName(DOWNLOAD_INTERRUPT_REASON_NONE,
                                        intermediate_path);
    return;
  }

  // Rename to intermediate name.
  // TODO(asanka): Skip this rename if AllDataSaved() is true. This avoids a
  //               spurious rename when we can just rename to the final
  //               filename. Unnecessary renames may cause bugs like
  //               http://crbug.com/74187.
  DCHECK(!is_save_package_download_);
  DCHECK(download_file_.get());
  DownloadFile::RenameCompletionCallback callback =
      base::Bind(&DownloadItemImpl::OnDownloadRenamedToIntermediateName,
                 weak_ptr_factory_.GetWeakPtr());
  BrowserThread::PostTask(
      BrowserThread::FILE, FROM_HERE,
      base::Bind(&DownloadFile::RenameAndUniquify,
                 // Safe because we control download file lifetime.
                 base::Unretained(download_file_.get()),
                 intermediate_path, callback));
}

void DownloadItemImpl::OnDownloadRenamedToIntermediateName(
    DownloadInterruptReason reason,
    const base::FilePath& full_path) {
  DCHECK(BrowserThread::CurrentlyOn(BrowserThread::UI));
  VLOG(20) << __FUNCTION__ << " download=" << DebugString(true);

  if (DOWNLOAD_INTERRUPT_REASON_NONE != destination_error_) {
    // Process destination error.  If both |reason| and |destination_error_|
    // refer to actual errors, we want to use the |destination_error_| as the
    // argument to the Interrupt() routine, as it happened first.
    if (reason == DOWNLOAD_INTERRUPT_REASON_NONE)
      SetFullPath(full_path);
    Interrupt(destination_error_);
    destination_error_ = DOWNLOAD_INTERRUPT_REASON_NONE;
  } else if (DOWNLOAD_INTERRUPT_REASON_NONE != reason) {
    Interrupt(reason);
    // All file errors result in file deletion above; no need to cleanup.  The
    // current_path_ should be empty. Resuming this download will force a
    // restart and a re-doing of filename determination.
    DCHECK(current_path_.empty());
  } else {
    SetFullPath(full_path);
    UpdateObservers();
    MaybeCompleteDownload();
  }
}

// When SavePackage downloads MHTML to GData (see
// SavePackageFilePickerChromeOS), GData calls MaybeCompleteDownload() like it
// does for non-SavePackage downloads, but SavePackage downloads never satisfy
// IsDownloadReadyForCompletion(). GDataDownloadObserver manually calls
// DownloadItem::UpdateObservers() when the upload completes so that SavePackage
// notices that the upload has completed and runs its normal Finish() pathway.
// MaybeCompleteDownload() is never the mechanism by which SavePackage completes
// downloads. SavePackage always uses its own Finish() to mark downloads
// complete.
void DownloadItemImpl::MaybeCompleteDownload() {
  DCHECK(BrowserThread::CurrentlyOn(BrowserThread::UI));
  DCHECK(!is_save_package_download_);

  if (!IsDownloadReadyForCompletion(
          base::Bind(&DownloadItemImpl::MaybeCompleteDownload,
                     weak_ptr_factory_.GetWeakPtr())))
    return;

  // TODO(rdsmith): DCHECK that we only pass through this point
  // once per download.  The natural way to do this is by a state
  // transition on the DownloadItem.

  // Confirm we're in the proper set of states to be here;
  // have all data, have a history handle, (validated or safe).
  DCHECK_EQ(IN_PROGRESS_INTERNAL, state_);
  DCHECK(!IsDangerous());
  DCHECK(all_data_saved_);

  OnDownloadCompleting();
}

// Called by MaybeCompleteDownload() when it has determined that the download
// is ready for completion.
void DownloadItemImpl::OnDownloadCompleting() {
  DCHECK(BrowserThread::CurrentlyOn(BrowserThread::UI));

  if (state_ != IN_PROGRESS_INTERNAL)
    return;

  VLOG(20) << __FUNCTION__ << "()"
           << " " << DebugString(true);
  DCHECK(!GetTargetFilePath().empty());
  DCHECK(!IsDangerous());

  // TODO(rdsmith/benjhayden): Remove as part of SavePackage integration.
  if (is_save_package_download_) {
    // Avoid doing anything on the file thread; there's nothing we control
    // there.
    // Strictly speaking, this skips giving the embedder a chance to open
    // the download.  But on a save package download, there's no real
    // concept of opening.
    Completed();
    return;
  }

  DCHECK(download_file_.get());
  // Unilaterally rename; even if it already has the right name,
  // we need theannotation.
  DownloadFile::RenameCompletionCallback callback =
      base::Bind(&DownloadItemImpl::OnDownloadRenamedToFinalName,
                 weak_ptr_factory_.GetWeakPtr());
  BrowserThread::PostTask(
      BrowserThread::FILE, FROM_HERE,
      base::Bind(&DownloadFile::RenameAndAnnotate,
                 base::Unretained(download_file_.get()),
                 GetTargetFilePath(), callback));
}

void DownloadItemImpl::OnDownloadRenamedToFinalName(
    DownloadInterruptReason reason,
    const base::FilePath& full_path) {
  DCHECK(BrowserThread::CurrentlyOn(BrowserThread::UI));
  DCHECK(!is_save_package_download_);

  // If a cancel or interrupt hit, we'll cancel the DownloadFile, which
  // will result in deleting the file on the file thread.  So we don't
  // care about the name having been changed.
  if (state_ != IN_PROGRESS_INTERNAL)
    return;

  VLOG(20) << __FUNCTION__ << "()"
           << " full_path = \"" << full_path.value() << "\""
           << " " << DebugString(false);

  if (DOWNLOAD_INTERRUPT_REASON_NONE != reason) {
    Interrupt(reason);

    // All file errors should have resulted in in file deletion above. On
    // resumption we will need to re-do filename determination.
    DCHECK(current_path_.empty());
    return;
  }

  DCHECK(target_path_ == full_path);

  if (full_path != current_path_) {
    // full_path is now the current and target file path.
    DCHECK(!full_path.empty());
    SetFullPath(full_path);
  }

  // Complete the download and release the DownloadFile.
  DCHECK(download_file_.get());
  ReleaseDownloadFile(false);

  // We're not completely done with the download item yet, but at this
  // point we're committed to complete the download.  Cancels (or Interrupts,
  // though it's not clear how they could happen) after this point will be
  // ignored.
  TransitionTo(COMPLETING_INTERNAL, DONT_UPDATE_OBSERVERS);

  if (delegate_->ShouldOpenDownload(
          this, base::Bind(&DownloadItemImpl::DelayedDownloadOpened,
                           weak_ptr_factory_.GetWeakPtr()))) {
    Completed();
  } else {
    delegate_delayed_complete_ = true;
    UpdateObservers();
  }
}

void DownloadItemImpl::DelayedDownloadOpened(bool auto_opened) {
  DCHECK(BrowserThread::CurrentlyOn(BrowserThread::UI));

  auto_opened_ = auto_opened;
  Completed();
}

void DownloadItemImpl::Completed() {
  DCHECK(BrowserThread::CurrentlyOn(BrowserThread::UI));

  VLOG(20) << __FUNCTION__ << "() " << DebugString(false);

  DCHECK(all_data_saved_);
  end_time_ = base::Time::Now();
  TransitionTo(COMPLETE_INTERNAL, UPDATE_OBSERVERS);
  RecordDownloadCompleted(start_tick_, received_bytes_);

  if (auto_opened_) {
    // If it was already handled by the delegate, do nothing.
  } else if (GetOpenWhenComplete() ||
             ShouldOpenFileBasedOnExtension() ||
             IsTemporary()) {
    // If the download is temporary, like in drag-and-drop, do not open it but
    // we still need to set it auto-opened so that it can be removed from the
    // download shelf.
    if (!IsTemporary())
      OpenDownload();

    auto_opened_ = true;
    UpdateObservers();
  }
}

void DownloadItemImpl::OnResumeRequestStarted(
    DownloadItem* item,
    DownloadInterruptReason interrupt_reason) {
  // If |item| is not NULL, then Start() has been called already, and nothing
  // more needs to be done here.
  if (item) {
    DCHECK_EQ(DOWNLOAD_INTERRUPT_REASON_NONE, interrupt_reason);
    DCHECK_EQ(static_cast<DownloadItem*>(this), item);
    return;
  }
  // Otherwise, the request failed without passing through
  // DownloadResourceHandler::OnResponseStarted.
  DCHECK_NE(DOWNLOAD_INTERRUPT_REASON_NONE, interrupt_reason);
  Interrupt(interrupt_reason);
}

// **** End of Download progression cascade

// An error occurred somewhere.
void DownloadItemImpl::Interrupt(DownloadInterruptReason reason) {
  DCHECK(BrowserThread::CurrentlyOn(BrowserThread::UI));
  DCHECK_NE(DOWNLOAD_INTERRUPT_REASON_NONE, reason);

  // Somewhat counter-intuitively, it is possible for us to receive an
  // interrupt after we've already been interrupted.  The generation of
  // interrupts from the file thread Renames and the generation of
  // interrupts from disk writes go through two different mechanisms (driven
  // by rename requests from UI thread and by write requests from IO thread,
  // respectively), and since we choose not to keep state on the File thread,
  // this is the place where the races collide.  It's also possible for
  // interrupts to race with cancels.

  // Whatever happens, the first one to hit the UI thread wins.
  if (state_ != IN_PROGRESS_INTERNAL && state_ != RESUMING_INTERNAL)
    return;

  last_reason_ = reason;

  ResumeMode resume_mode = GetResumeMode();

  if (state_ == IN_PROGRESS_INTERNAL) {
    // Cancel (delete file) if:
    // 1) we're going to restart.
    // 2) Resumption isn't possible (download was cancelled or blocked due to
    //    security restrictions).
    // 3) Resumption isn't enabled.
    // No point in leaving data around we aren't going to use.
    ReleaseDownloadFile(resume_mode == RESUME_MODE_IMMEDIATE_RESTART ||
                        resume_mode == RESUME_MODE_USER_RESTART ||
                        resume_mode == RESUME_MODE_INVALID ||
                        !IsDownloadResumptionEnabled());

    // Cancel the originating URL request.
    request_handle_->CancelRequest();
  } else {
    DCHECK(!download_file_.get());
  }

  // Reset all data saved, as even if we did save all the data we're going
  // to go through another round of downloading when we resume.
  // There's a potential problem here in the abstract, as if we did download
  // all the data and then run into a continuable error, on resumption we
  // won't download any more data.  However, a) there are currently no
  // continuable errors that can occur after we download all the data, and
  // b) if there were, that would probably simply result in a null range
  // request, which would generate a DestinationCompleted() notification
  // from the DownloadFile, which would behave properly with setting
  // all_data_saved_ to false here.
  all_data_saved_ = false;

  TransitionTo(INTERRUPTED_INTERNAL, DONT_UPDATE_OBSERVERS);
  RecordDownloadInterrupted(reason, received_bytes_, total_bytes_);
  if (!GetWebContents())
    RecordDownloadCount(INTERRUPTED_WITHOUT_WEBCONTENTS);

  AutoResumeIfValid();
  UpdateObservers();
}

void DownloadItemImpl::ReleaseDownloadFile(bool destroy_file) {
  DCHECK(BrowserThread::CurrentlyOn(BrowserThread::UI));

  if (destroy_file) {
    BrowserThread::PostTask(
        BrowserThread::FILE, FROM_HERE,
        // Will be deleted at end of task execution.
        base::Bind(&DownloadFileCancel, base::Passed(&download_file_)));
    // Avoid attempting to reuse the intermediate file by clearing out
    // current_path_.
    current_path_.clear();
  } else {
    BrowserThread::PostTask(
        BrowserThread::FILE,
        FROM_HERE,
        base::Bind(base::IgnoreResult(&DownloadFileDetach),
                   // Will be deleted at end of task execution.
                   base::Passed(&download_file_)));
  }
  // Don't accept any more messages from the DownloadFile, and null
  // out any previous "all data received".  This also breaks links to
  // other entities we've given out weak pointers to.
  weak_ptr_factory_.InvalidateWeakPtrs();
}

bool DownloadItemImpl::IsDownloadReadyForCompletion(
    const base::Closure& state_change_notification) {
  // If we don't have all the data, the download is not ready for
  // completion.
  if (!AllDataSaved())
    return false;

  // If the download is dangerous, but not yet validated, it's not ready for
  // completion.
  if (IsDangerous())
    return false;

  // If the download isn't active (e.g. has been cancelled) it's not
  // ready for completion.
  if (state_ != IN_PROGRESS_INTERNAL)
    return false;

  // If the target filename hasn't been determined, then it's not ready for
  // completion. This is checked in ReadyForDownloadCompletionDone().
  if (GetTargetFilePath().empty())
    return false;

  // This is checked in NeedsRename(). Without this conditional,
  // browser_tests:DownloadTest.DownloadMimeType fails the DCHECK.
  if (target_path_.DirName() != current_path_.DirName())
    return false;

  // Give the delegate a chance to hold up a stop sign.  It'll call
  // use back through the passed callback if it does and that state changes.
  if (!delegate_->ShouldCompleteDownload(this, state_change_notification))
    return false;

  return true;
}

void DownloadItemImpl::TransitionTo(DownloadInternalState new_state,
                                    ShouldUpdateObservers notify_action) {
  DCHECK(BrowserThread::CurrentlyOn(BrowserThread::UI));

  if (state_ == new_state)
    return;

  DownloadInternalState old_state = state_;
  state_ = new_state;

  switch (state_) {
    case COMPLETING_INTERNAL:
      bound_net_log_.AddEvent(
          net::NetLog::TYPE_DOWNLOAD_ITEM_COMPLETING,
          base::Bind(&ItemCompletingNetLogCallback, received_bytes_, &hash_));
      break;
    case COMPLETE_INTERNAL:
      bound_net_log_.AddEvent(
          net::NetLog::TYPE_DOWNLOAD_ITEM_FINISHED,
          base::Bind(&ItemFinishedNetLogCallback, auto_opened_));
      break;
    case INTERRUPTED_INTERNAL:
      bound_net_log_.AddEvent(
          net::NetLog::TYPE_DOWNLOAD_ITEM_INTERRUPTED,
          base::Bind(&ItemInterruptedNetLogCallback, last_reason_,
                     received_bytes_, &hash_state_));
      break;
    case IN_PROGRESS_INTERNAL:
      if (old_state == INTERRUPTED_INTERNAL) {
        bound_net_log_.AddEvent(
            net::NetLog::TYPE_DOWNLOAD_ITEM_RESUMED,
            base::Bind(&ItemResumingNetLogCallback,
                       false, last_reason_, received_bytes_, &hash_state_));
      }
      break;
    case CANCELLED_INTERNAL:
      bound_net_log_.AddEvent(
          net::NetLog::TYPE_DOWNLOAD_ITEM_CANCELED,
          base::Bind(&ItemCanceledNetLogCallback, received_bytes_,
                     &hash_state_));
      break;
    default:
      break;
  }

  VLOG(20) << " " << __FUNCTION__ << "()" << " this = " << DebugString(true)
    << " " << InternalToExternalState(old_state)
    << " " << InternalToExternalState(state_);

  bool is_done = (state_ != IN_PROGRESS_INTERNAL &&
                  state_ != COMPLETING_INTERNAL);
  bool was_done = (old_state != IN_PROGRESS_INTERNAL &&
                   old_state != COMPLETING_INTERNAL);
  // Termination
  if (is_done && !was_done)
    bound_net_log_.EndEvent(net::NetLog::TYPE_DOWNLOAD_ITEM_ACTIVE);

  // Resumption
  if (was_done && !is_done) {
    std::string file_name(target_path_.BaseName().AsUTF8Unsafe());
    bound_net_log_.BeginEvent(net::NetLog::TYPE_DOWNLOAD_ITEM_ACTIVE,
                              base::Bind(&ItemActivatedNetLogCallback,
                                         this, SRC_ACTIVE_DOWNLOAD,
                                         &file_name));
  }

  if (notify_action == UPDATE_OBSERVERS)
    UpdateObservers();
}

void DownloadItemImpl::SetDangerType(DownloadDangerType danger_type) {
  if (danger_type != danger_type_) {
    bound_net_log_.AddEvent(
        net::NetLog::TYPE_DOWNLOAD_ITEM_SAFETY_STATE_UPDATED,
        base::Bind(&ItemCheckedNetLogCallback, danger_type));
  }
  // Only record the Malicious UMA stat if it's going from {not malicious} ->
  // {malicious}.
  if ((danger_type_ == DOWNLOAD_DANGER_TYPE_NOT_DANGEROUS ||
       danger_type_ == DOWNLOAD_DANGER_TYPE_DANGEROUS_FILE ||
       danger_type_ == DOWNLOAD_DANGER_TYPE_UNCOMMON_CONTENT ||
       danger_type_ == DOWNLOAD_DANGER_TYPE_MAYBE_DANGEROUS_CONTENT) &&
      (danger_type == DOWNLOAD_DANGER_TYPE_DANGEROUS_HOST ||
       danger_type == DOWNLOAD_DANGER_TYPE_DANGEROUS_URL ||
       danger_type == DOWNLOAD_DANGER_TYPE_DANGEROUS_CONTENT ||
       danger_type == DOWNLOAD_DANGER_TYPE_POTENTIALLY_UNWANTED)) {
    RecordMaliciousDownloadClassified(danger_type);
  }
  danger_type_ = danger_type;
}

void DownloadItemImpl::SetFullPath(const base::FilePath& new_path) {
  DCHECK(BrowserThread::CurrentlyOn(BrowserThread::UI));
  VLOG(20) << __FUNCTION__ << "()"
           << " new_path = \"" << new_path.value() << "\""
           << " " << DebugString(true);
  DCHECK(!new_path.empty());

  bound_net_log_.AddEvent(
      net::NetLog::TYPE_DOWNLOAD_ITEM_RENAMED,
      base::Bind(&ItemRenamedNetLogCallback, &current_path_, &new_path));

  current_path_ = new_path;
}

void DownloadItemImpl::AutoResumeIfValid() {
  DVLOG(20) << __FUNCTION__ << "() " << DebugString(true);
  DCHECK(BrowserThread::CurrentlyOn(BrowserThread::UI));
  ResumeMode mode = GetResumeMode();

  if (mode != RESUME_MODE_IMMEDIATE_RESTART &&
      mode != RESUME_MODE_IMMEDIATE_CONTINUE) {
    return;
  }

  auto_resume_count_++;

  ResumeInterruptedDownload();
}

void DownloadItemImpl::ResumeInterruptedDownload() {
  DCHECK(BrowserThread::CurrentlyOn(BrowserThread::UI));

  // If the flag for downloads resumption isn't enabled, ignore
  // this request.
  const CommandLine& command_line = *CommandLine::ForCurrentProcess();
  if (!command_line.HasSwitch(switches::kEnableDownloadResumption))
    return;

  // If we're not interrupted, ignore the request; our caller is drunk.
  if (state_ != INTERRUPTED_INTERNAL)
    return;

  // If we can't get a web contents, we can't resume the download.
  // TODO(rdsmith): Find some alternative web contents to use--this
  // means we can't restart a download if it's a download imported
  // from the history.
  if (!GetWebContents())
    return;

  // Reset the appropriate state if restarting.
  ResumeMode mode = GetResumeMode();
  if (mode == RESUME_MODE_IMMEDIATE_RESTART ||
      mode == RESUME_MODE_USER_RESTART) {
    received_bytes_ = 0;
    hash_state_ = "";
    last_modified_time_ = "";
    etag_ = "";
  }

  scoped_ptr<DownloadUrlParameters> download_params(
      DownloadUrlParameters::FromWebContents(GetWebContents(),
                                             GetOriginalUrl()));

  download_params->set_file_path(GetFullPath());
  download_params->set_offset(GetReceivedBytes());
  download_params->set_hash_state(GetHashState());
  download_params->set_last_modified(GetLastModifiedTime());
  download_params->set_etag(GetETag());
  download_params->set_callback(
      base::Bind(&DownloadItemImpl::OnResumeRequestStarted,
                 weak_ptr_factory_.GetWeakPtr()));

  delegate_->ResumeInterruptedDownload(download_params.Pass(), GetId());
  // Just in case we were interrupted while paused.
  is_paused_ = false;

  TransitionTo(RESUMING_INTERNAL, DONT_UPDATE_OBSERVERS);
}

// static
DownloadItem::DownloadState DownloadItemImpl::InternalToExternalState(
    DownloadInternalState internal_state) {
  switch (internal_state) {
    case IN_PROGRESS_INTERNAL:
      return IN_PROGRESS;
    case COMPLETING_INTERNAL:
      return IN_PROGRESS;
    case COMPLETE_INTERNAL:
      return COMPLETE;
    case CANCELLED_INTERNAL:
      return CANCELLED;
    case INTERRUPTED_INTERNAL:
      return INTERRUPTED;
    case RESUMING_INTERNAL:
      return INTERRUPTED;
    case MAX_DOWNLOAD_INTERNAL_STATE:
      break;
  }
  NOTREACHED();
  return MAX_DOWNLOAD_STATE;
}

// static
DownloadItemImpl::DownloadInternalState
DownloadItemImpl::ExternalToInternalState(
    DownloadState external_state) {
  switch (external_state) {
    case IN_PROGRESS:
      return IN_PROGRESS_INTERNAL;
    case COMPLETE:
      return COMPLETE_INTERNAL;
    case CANCELLED:
      return CANCELLED_INTERNAL;
    case INTERRUPTED:
      return INTERRUPTED_INTERNAL;
    default:
      NOTREACHED();
  }
  return MAX_DOWNLOAD_INTERNAL_STATE;
}

const char* DownloadItemImpl::DebugDownloadStateString(
    DownloadInternalState state) {
  switch (state) {
    case IN_PROGRESS_INTERNAL:
      return "IN_PROGRESS";
    case COMPLETING_INTERNAL:
      return "COMPLETING";
    case COMPLETE_INTERNAL:
      return "COMPLETE";
    case CANCELLED_INTERNAL:
      return "CANCELLED";
    case INTERRUPTED_INTERNAL:
      return "INTERRUPTED";
    case RESUMING_INTERNAL:
      return "RESUMING";
    case MAX_DOWNLOAD_INTERNAL_STATE:
      break;
  };
  NOTREACHED() << "Unknown download state " << state;
  return "unknown";
}

const char* DownloadItemImpl::DebugResumeModeString(ResumeMode mode) {
  switch (mode) {
    case RESUME_MODE_INVALID:
      return "INVALID";
    case RESUME_MODE_IMMEDIATE_CONTINUE:
      return "IMMEDIATE_CONTINUE";
    case RESUME_MODE_IMMEDIATE_RESTART:
      return "IMMEDIATE_RESTART";
    case RESUME_MODE_USER_CONTINUE:
      return "USER_CONTINUE";
    case RESUME_MODE_USER_RESTART:
      return "USER_RESTART";
  }
  NOTREACHED() << "Unknown resume mode " << mode;
  return "unknown";
}

}  // namespace content
/* [<][>][^][v][top][bottom][index][help] */
root/content/browser/download/download_item_impl.cc

DEFINITIONS
