Attempt 3 at: Splits ChromeURLDataManager into 2 chunks:...

chrome/browser/dom_ui/chrome_url_data_manager.cc

Index: chrome/browser/dom_ui/chrome_url_data_manager.cc
===================================================================
--- chrome/browser/dom_ui/chrome_url_data_manager.cc	(revision 74394)
+++ chrome/browser/dom_ui/chrome_url_data_manager.cc	(working copy)
@@ -4,332 +4,132 @@
 
 #include "chrome/browser/dom_ui/chrome_url_data_manager.h"
 
-#include "base/file_util.h"
+#include <vector>
+
 #include "base/i18n/rtl.h"
 #include "base/message_loop.h"
-#include "base/path_service.h"
 #include "base/ref_counted_memory.h"
-#include "base/singleton.h"
-#include "base/stl_util-inl.h"
 #include "base/string_util.h"
-#include "base/threading/thread.h"
+#include "base/synchronization/lock.h"
 #include "base/values.h"
-#if defined(OS_WIN)
-#include "base/win/windows_version.h"
-#endif
-#include "chrome/browser/appcache/view_appcache_internals_job_factory.h"
 #include "chrome/browser/browser_thread.h"
-#include "chrome/browser/dom_ui/shared_resources_data_source.h"
+#include "chrome/browser/dom_ui/chrome_url_data_manager_backend.h"
 #include "chrome/browser/net/chrome_url_request_context.h"
-#include "chrome/browser/net/view_blob_internals_job_factory.h"
-#include "chrome/browser/net/view_http_cache_job_factory.h"
-#include "chrome/common/chrome_paths.h"
-#include "chrome/common/ref_counted_util.h"
-#include "chrome/common/url_constants.h"
-#include "googleurl/src/url_util.h"
+#include "chrome/browser/profiles/profile.h"
 #include "grit/platform_locale_settings.h"
-#include "net/base/io_buffer.h"
-#include "net/base/net_errors.h"
-#include "net/url_request/url_request.h"
-#include "net/url_request/url_request_file_job.h"
-#include "net/url_request/url_request_job.h"
 #include "ui/base/l10n/l10n_util.h"
 
-// URLRequestChromeJob is a net::URLRequestJob that manages running
-// chrome-internal resource requests asynchronously.
-// It hands off URL requests to ChromeURLDataManager, which asynchronously
-// calls back once the data is available.
-class URLRequestChromeJob : public net::URLRequestJob {
- public:
-  explicit URLRequestChromeJob(net::URLRequest* request);
+#if defined(OS_WIN)
+#include "base/win/windows_version.h"
+#endif
 
-  // net::URLRequestJob implementation.
-  virtual void Start();
-  virtual void Kill();
-  virtual bool ReadRawData(net::IOBuffer* buf, int buf_size, int *bytes_read);
-  virtual bool GetMimeType(std::string* mime_type) const;
+// static
+base::Lock ChromeURLDataManager::delete_lock_;
 
-  // Called by ChromeURLDataManager to notify us that the data blob is ready
-  // for us.
-  void DataAvailable(RefCountedMemory* bytes);
-
-  void SetMimeType(const std::string& mime_type) {
-    mime_type_ = mime_type;
-  }
-
- private:
-  virtual ~URLRequestChromeJob();
-
-  // Helper for Start(), to let us start asynchronously.
-  // (This pattern is shared by most net::URLRequestJob implementations.)
-  void StartAsync();
-
-  // Do the actual copy from data_ (the data we're serving) into |buf|.
-  // Separate from ReadRawData so we can handle async I/O.
-  void CompleteRead(net::IOBuffer* buf, int buf_size, int* bytes_read);
-
-  // The actual data we're serving.  NULL until it's been fetched.
-  scoped_refptr<RefCountedMemory> data_;
-  // The current offset into the data that we're handing off to our
-  // callers via the Read interfaces.
-  int data_offset_;
-
-  // For async reads, we keep around a pointer to the buffer that
-  // we're reading into.
-  scoped_refptr<net::IOBuffer> pending_buf_;
-  int pending_buf_size_;
-  std::string mime_type_;
-
-  DISALLOW_COPY_AND_ASSIGN(URLRequestChromeJob);
-};
-
-// URLRequestChromeFileJob is a net::URLRequestJob that acts like a file:// URL
-class URLRequestChromeFileJob : public net::URLRequestFileJob {
- public:
-  URLRequestChromeFileJob(net::URLRequest* request, const FilePath& path);
-
- private:
-  virtual ~URLRequestChromeFileJob();
-
-  DISALLOW_COPY_AND_ASSIGN(URLRequestChromeFileJob);
-};
-
-void RegisterURLRequestChromeJob() {
-  FilePath inspector_dir;
-  if (PathService::Get(chrome::DIR_INSPECTOR, &inspector_dir)) {
-    ChromeURLDataManager::GetInstance()->AddFileSource(
-        chrome::kChromeUIDevToolsHost, inspector_dir);
-  }
-
-  SharedResourcesDataSource::Register();
-  net::URLRequest::RegisterProtocolFactory(chrome::kChromeDevToolsScheme,
-                                           &ChromeURLDataManager::Factory);
-  net::URLRequest::RegisterProtocolFactory(chrome::kChromeUIScheme,
-                                           &ChromeURLDataManager::Factory);
-}
-
-void UnregisterURLRequestChromeJob() {
-  FilePath inspector_dir;
-  if (PathService::Get(chrome::DIR_INSPECTOR, &inspector_dir)) {
-    ChromeURLDataManager::GetInstance()->RemoveFileSource(
-        chrome::kChromeUIDevToolsHost);
-  }
-}
-
 // static
-void ChromeURLDataManager::URLToRequest(const GURL& url,
-                                        std::string* source_name,
-                                        std::string* path) {
-  DCHECK(url.SchemeIs(chrome::kChromeDevToolsScheme) ||
-         url.SchemeIs(chrome::kChromeUIScheme));
+ChromeURLDataManager::DataSources* ChromeURLDataManager::data_sources_ = NULL;
 
-  if (!url.is_valid()) {
-    NOTREACHED();
-    return;
-  }
-
-  // Our input looks like: chrome://source_name/extra_bits?foo .
-  // So the url's "host" is our source, and everything after the host is
-  // the path.
-  source_name->assign(url.host());
-
-  const std::string& spec = url.possibly_invalid_spec();
-  const url_parse::Parsed& parsed = url.parsed_for_possibly_invalid_spec();
-  // + 1 to skip the slash at the beginning of the path.
-  int offset = parsed.CountCharactersBefore(url_parse::Parsed::PATH, false) + 1;
-
-  if (offset < static_cast<int>(spec.size()))
-    path->assign(spec.substr(offset));
+// Invoked on the IO thread to do the actual adding of the DataSource.
+static void AddDataSourceOnIOThread(
+    scoped_refptr<URLRequestContextGetter> context_getter,
+    scoped_refptr<ChromeURLDataManager::DataSource> data_source) {
+  DCHECK(BrowserThread::CurrentlyOn(BrowserThread::IO));
+  static_cast<ChromeURLRequestContext*>(
+      context_getter->GetURLRequestContext())->
+      GetChromeURLDataManagerBackend()->AddDataSource(data_source.get());
 }
 
-// static
-bool ChromeURLDataManager::URLToFilePath(const GURL& url,
-                                         FilePath* file_path) {
-  // Parse the URL into a request for a source and path.
-  std::string source_name;
-  std::string relative_path;
-
-  // Remove Query and Ref from URL.
-  GURL stripped_url;
-  GURL::Replacements replacements;
-  replacements.ClearQuery();
-  replacements.ClearRef();
-  stripped_url = url.ReplaceComponents(replacements);
-
-  URLToRequest(stripped_url, &source_name, &relative_path);
-
-  FileSourceMap::const_iterator i(
-      ChromeURLDataManager::GetInstance()->file_sources_.find(source_name));
-  if (i == ChromeURLDataManager::GetInstance()->file_sources_.end())
-    return false;
-
-  // Check that |relative_path| is not an absolute path (otherwise AppendASCII()
-  // will DCHECK). The awkward use of StringType is because on some systems
-  // FilePath expects a std::string, but on others a std::wstring.
-  FilePath p(FilePath::StringType(relative_path.begin(), relative_path.end()));
-  if (p.IsAbsolute())
-    return false;
-
-  *file_path = i->second.AppendASCII(relative_path);
-
-  return true;
+ChromeURLDataManager::ChromeURLDataManager(Profile* profile)
+    : profile_(profile) {
 }
 
-ChromeURLDataManager::ChromeURLDataManager() : next_request_id_(0) { }
-
 ChromeURLDataManager::~ChromeURLDataManager() {
-  // This is used as a Singleton, so it is only called at exit cleanup time.
-  // This means it is called on the main (UI) thread.
-  //
-  // It will break if it is called at shutdown time on a different thread, as
-  // it will attempt to call the destructors for its |data_source_|s on the
-  // UI thread, but the UI thread's message loop will be not be running
-  // -- so the destructor calls will be dropped and we will leak the objects.
 }
 
-// static
-ChromeURLDataManager* ChromeURLDataManager::GetInstance() {
-  return Singleton<ChromeURLDataManager>::get();
+void ChromeURLDataManager::AddDataSource(DataSource* source) {
+  DCHECK(BrowserThread::CurrentlyOn(BrowserThread::UI));
+  BrowserThread::PostTask(
+      BrowserThread::IO, FROM_HERE,
+      NewRunnableFunction(AddDataSourceOnIOThread,
+                          make_scoped_refptr(profile_->GetRequestContext()),
+                          make_scoped_refptr(source)));
 }
 
-void ChromeURLDataManager::AddDataSource(scoped_refptr<DataSource> source) {
-  // Some |DataSource|-derived classes, notably |FileIconSource| and
-  // |WebUIFavIconSource|, have members that will DCHECK if they are not
-  // destructed in the same thread as they are constructed (the UI thread).
-  //
-  // If |AddDataSource| is called more than once, it will destruct the object
-  // that it had before, as it is the only thing still holding a reference to
-  // that object.  |DataSource| uses the |DeleteOnUIThread| trait to insure
-  // that the destructor is called on the UI thread.
-  //
-  // TODO(jackson): A new data source with same name should not clobber the
-  // existing one.
-  data_sources_[source->source_name()] = source;
+// static
+void ChromeURLDataManager::DeleteDataSources() {
+  DCHECK(BrowserThread::CurrentlyOn(BrowserThread::UI));
+  DataSources sources;
+  {
+    base::AutoLock lock(delete_lock_);
+    if (!data_sources_)
+      return;
+    data_sources_->swap(sources);
+  }
+  for (size_t i = 0; i < sources.size(); ++i)
+    delete sources[i];
 }
 
-void ChromeURLDataManager::RemoveDataSourceForTest(const char* source_name) {
-  DataSourceMap::iterator i = data_sources_.find(source_name);
-  if (i == data_sources_.end())
+// static
+void ChromeURLDataManager::DeleteDataSource(const DataSource* data_source) {
+  // Invoked when a DataSource is no longer referenced and needs to be deleted.
+  if (BrowserThread::CurrentlyOn(BrowserThread::UI)) {
+    // We're on the UI thread, delete right away.
+    delete data_source;
     return;
-  (*i).second = NULL;  // Calls Release().
-  data_sources_.erase(i);
-}
-
-void ChromeURLDataManager::RemoveAllDataSources() {
-  for (DataSourceMap::iterator i = data_sources_.begin();
-       i != data_sources_.end();
-       i = data_sources_.begin()) {
-    (*i).second = NULL;  // Calls Release().
-    data_sources_.erase(i);
   }
-}
 
-void ChromeURLDataManager::AddFileSource(const std::string& source_name,
-                                         const FilePath& file_path) {
-  DCHECK(file_sources_.count(source_name) == 0);
-  file_sources_[source_name] = file_path;
-}
-
-void ChromeURLDataManager::RemoveFileSource(const std::string& source_name) {
-  DCHECK(file_sources_.count(source_name) == 1);
-  file_sources_.erase(source_name);
-}
-
-bool ChromeURLDataManager::HasPendingJob(URLRequestChromeJob* job) const {
-  for (PendingRequestMap::const_iterator i = pending_requests_.begin();
-       i != pending_requests_.end(); ++i) {
-    if (i->second == job)
-      return true;
+  // We're not on the UI thread, add the DataSource to the list of DataSources
+  // to delete.
+  bool schedule_delete = false;
+  {
+    base::AutoLock lock(delete_lock_);
+    if (!data_sources_)
+      data_sources_ = new DataSources();
+    schedule_delete = data_sources_->empty();
+    data_sources_->push_back(data_source);
   }
-
-  return false;
+  if (schedule_delete) {
+    // Schedule a task to delete the DataSource back on the UI thread.
+    BrowserThread::PostTask(BrowserThread::UI,
+                            FROM_HERE,
+                            NewRunnableFunction(
+                                &ChromeURLDataManager::DeleteDataSources));
+  }
 }
 
-bool ChromeURLDataManager::StartRequest(const GURL& url,
-                                        URLRequestChromeJob* job) {
-  // Parse the URL into a request for a source and path.
-  std::string source_name;
-  std::string path;
-  URLToRequest(url, &source_name, &path);
-
-  // Look up the data source for the request.
-  DataSourceMap::iterator i = data_sources_.find(source_name);
-  if (i == data_sources_.end())
+// static
+bool ChromeURLDataManager::IsScheduledForDeletion(
+    const DataSource* data_source) {
+  base::AutoLock lock(delete_lock_);
+  if (!data_sources_)
     return false;
-  DataSource* source = i->second;
-
-  // Save this request so we know where to send the data.
-  RequestID request_id = next_request_id_++;
-  pending_requests_.insert(std::make_pair(request_id, job));
-
-  // TODO(eroman): would be nicer if the mimetype were set at the same time
-  // as the data blob. For now do it here, since NotifyHeadersComplete() is
-  // going to get called once we return.
-  job->SetMimeType(source->GetMimeType(path));
-
-  ChromeURLRequestContext* context = static_cast<ChromeURLRequestContext*>(
-      job->request()->context());
-
-  // Forward along the request to the data source.
-  MessageLoop* target_message_loop = source->MessageLoopForRequestPath(path);
-  if (!target_message_loop) {
-    // The DataSource is agnostic to which thread StartDataRequest is called
-    // on for this path.  Call directly into it from this thread, the IO
-    // thread.
-    source->StartDataRequest(path, context->is_off_the_record(), request_id);
-  } else {
-    // The DataSource wants StartDataRequest to be called on a specific thread,
-    // usually the UI thread, for this path.
-    target_message_loop->PostTask(FROM_HERE,
-        NewRunnableMethod(source, &DataSource::StartDataRequest,
-                          path, context->is_off_the_record(), request_id));
-  }
-  return true;
+  return std::find(data_sources_.begin(), data_sources_.end(), data_source) !=
+      data_source->end();
 }
 
-void ChromeURLDataManager::RemoveRequest(URLRequestChromeJob* job) {
-  // Remove the request from our list of pending requests.
-  // If/when the source sends the data that was requested, the data will just
-  // be thrown away.
-  for (PendingRequestMap::iterator i = pending_requests_.begin();
-       i != pending_requests_.end(); ++i) {
-    if (i->second == job) {
-      pending_requests_.erase(i);
-      return;
-    }
-  }
-}
-
-void ChromeURLDataManager::DataAvailable(
-    RequestID request_id,
-    scoped_refptr<RefCountedMemory> bytes) {
-  // Forward this data on to the pending net::URLRequest, if it exists.
-  PendingRequestMap::iterator i = pending_requests_.find(request_id);
-  if (i != pending_requests_.end()) {
-    // We acquire a reference to the job so that it doesn't disappear under the
-    // feet of any method invoked here (we could trigger a callback).
-    scoped_refptr<URLRequestChromeJob> job(i->second);
-    pending_requests_.erase(i);
-    job->DataAvailable(bytes);
-  }
-}
-
 ChromeURLDataManager::DataSource::DataSource(const std::string& source_name,
                                              MessageLoop* message_loop)
-    : source_name_(source_name), message_loop_(message_loop) {
+    : source_name_(source_name),
+      message_loop_(message_loop),
+      backend_(NULL) {
 }
 
 ChromeURLDataManager::DataSource::~DataSource() {
 }
 
-void ChromeURLDataManager::DataSource::SendResponse(
-    RequestID request_id,
-    RefCountedMemory* bytes) {
+void ChromeURLDataManager::DataSource::SendResponse(int request_id,
+                                                    RefCountedMemory* bytes) {
+  if (IsScheduledForDeletion(this)) {

[willchan no longer on Chromium, 2011/02/10 03:51:36]

If we're scheduled for deletion, that means the refcount is 0. How is
SendResponse() getting invoked? This is a bug. I realize you didn't cause this
bug, but we should at least document it (file a bug for it). If you have any
idea which DataSource is being evil (someone must be holding a raw pointer),
then please note that down in the bug.

I'm OK with this hack, but we should definitely file a bug to fix this. Please
reference the bug here.

+    // We're scheduled for deletion. Servicing the request would result in
+    // this->AddRef being invoked, even though the ref count is 0 and 'this' is
+    // about to be deleted. If the AddRef were allowed through, when 'this' is
+    // released it would be deleted again.
+    return;
+  }
   BrowserThread::PostTask(
       BrowserThread::IO, FROM_HERE,
-      NewRunnableMethod(ChromeURLDataManager::GetInstance(),
-                        &ChromeURLDataManager::DataAvailable,
-                        request_id, scoped_refptr<RefCountedMemory>(bytes)));
+      NewRunnableMethod(this, &DataSource::SendResponseOnIOThread,
+                        request_id, make_scoped_refptr(bytes)));
 }
 
 MessageLoop* ChromeURLDataManager::DataSource::MessageLoopForRequestPath(
@@ -357,120 +157,10 @@
       base::i18n::IsRTL() ? "rtl" : "ltr");
 }
 
-net::URLRequestJob* ChromeURLDataManager::Factory(net::URLRequest* request,
-                                                  const std::string& scheme) {
-  // Try first with a file handler
-  FilePath path;
-  if (ChromeURLDataManager::URLToFilePath(request->url(), &path))
-    return new URLRequestChromeFileJob(request, path);
-
-  // Next check for chrome://view-http-cache/*, which uses its own job type.
-  if (ViewHttpCacheJobFactory::IsSupportedURL(request->url()))
-    return ViewHttpCacheJobFactory::CreateJobForRequest(request);
-
-  // Next check for chrome://appcache-internals/, which uses its own job type.
-  if (ViewAppCacheInternalsJobFactory::IsSupportedURL(request->url()))
-    return ViewAppCacheInternalsJobFactory::CreateJobForRequest(request);
-
-  // Next check for chrome://blob-internals/, which uses its own job type.
-  if (ViewBlobInternalsJobFactory::IsSupportedURL(request->url()))
-    return ViewBlobInternalsJobFactory::CreateJobForRequest(request);
-
-  // Fall back to using a custom handler
-  return new URLRequestChromeJob(request);
+void ChromeURLDataManager::DataSource::SendResponseOnIOThread(
+    int request_id,
+    scoped_refptr<RefCountedMemory> bytes) {
+  DCHECK(BrowserThread::CurrentlyOn(BrowserThread::IO));
+  if (backend_)
+    backend_->DataAvailable(request_id, bytes);
 }
-
-URLRequestChromeJob::URLRequestChromeJob(net::URLRequest* request)
-    : net::URLRequestJob(request),
-      data_offset_(0),
-      pending_buf_size_(0) {
-}
-
-URLRequestChromeJob::~URLRequestChromeJob() {
-  CHECK(!ChromeURLDataManager::GetInstance()->HasPendingJob(this));
-}
-
-void URLRequestChromeJob::Start() {
-  // Start reading asynchronously so that all error reporting and data
-  // callbacks happen as they would for network requests.
-  MessageLoop::current()->PostTask(FROM_HERE, NewRunnableMethod(
-      this, &URLRequestChromeJob::StartAsync));
-}
-
-void URLRequestChromeJob::Kill() {
-  ChromeURLDataManager::GetInstance()->RemoveRequest(this);
-}
-
-bool URLRequestChromeJob::GetMimeType(std::string* mime_type) const {
-  *mime_type = mime_type_;
-  return !mime_type_.empty();
-}
-
-void URLRequestChromeJob::DataAvailable(RefCountedMemory* bytes) {
-  if (bytes) {
-    // The request completed, and we have all the data.
-    // Clear any IO pending status.
-    SetStatus(net::URLRequestStatus());
-
-    data_ = bytes;
-    int bytes_read;
-    if (pending_buf_.get()) {
-      CHECK(pending_buf_->data());
-      CompleteRead(pending_buf_, pending_buf_size_, &bytes_read);
-      pending_buf_ = NULL;
-      NotifyReadComplete(bytes_read);
-    }
-  } else {
-    // The request failed.
-    NotifyDone(net::URLRequestStatus(net::URLRequestStatus::FAILED,
-                                     net::ERR_FAILED));
-  }
-}
-
-bool URLRequestChromeJob::ReadRawData(net::IOBuffer* buf, int buf_size,
-                                      int* bytes_read) {
-  if (!data_.get()) {
-    SetStatus(net::URLRequestStatus(net::URLRequestStatus::IO_PENDING, 0));
-    DCHECK(!pending_buf_.get());
-    CHECK(buf->data());
-    pending_buf_ = buf;
-    pending_buf_size_ = buf_size;
-    return false;  // Tell the caller we're still waiting for data.
-  }
-
-  // Otherwise, the data is available.
-  CompleteRead(buf, buf_size, bytes_read);
-  return true;
-}
-
-void URLRequestChromeJob::CompleteRead(net::IOBuffer* buf, int buf_size,
-                                       int* bytes_read) {
-  int remaining = static_cast<int>(data_->size()) - data_offset_;
-  if (buf_size > remaining)
-    buf_size = remaining;
-  if (buf_size > 0) {
-    memcpy(buf->data(), data_->front() + data_offset_, buf_size);
-    data_offset_ += buf_size;
-  }
-  *bytes_read = buf_size;
-}
-
-void URLRequestChromeJob::StartAsync() {
-  if (!request_)
-    return;
-
-  if (ChromeURLDataManager::GetInstance()->StartRequest(request_->url(),
-                                                        this)) {
-    NotifyHeadersComplete();
-  } else {
-    NotifyStartError(net::URLRequestStatus(net::URLRequestStatus::FAILED,
-                                           net::ERR_INVALID_URL));
-  }
-}
-
-URLRequestChromeFileJob::URLRequestChromeFileJob(net::URLRequest* request,
-                                                 const FilePath& path)
-    : net::URLRequestFileJob(request, path) {
-}
-
-URLRequestChromeFileJob::~URLRequestChromeFileJob() { }