view-cache: Refactor ViewCacheHelper and ViewHttpCacheJobFactory...

chrome/browser/net/view_http_cache_job_factory.cc

 // Copyright (c) 2010 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.
 
 #include "chrome/browser/net/view_http_cache_job_factory.h"
 
+#include "base/message_loop.h"
 #include "chrome/common/url_constants.h"
+#include "net/base/net_errors.h"
 #include "net/url_request/url_request.h"
 #include "net/url_request/url_request_context.h"
 #include "net/url_request/url_request_simple_job.h"
 #include "net/url_request/view_cache_helper.h"
 
 namespace {
 
 // A job subclass that dumps an HTTP cache entry.
-class ViewHttpCacheJob : public URLRequestSimpleJob {
+class ViewHttpCacheJob : public URLRequestJob {
  public:
   explicit ViewHttpCacheJob(URLRequest* request)
-      : URLRequestSimpleJob(request) {}
+      : URLRequestJob(request), data_offset_(0),
+        ALLOW_THIS_IN_INITIALIZER_LIST(
+            callback_(this, &ViewHttpCacheJob::OnIOComplete)) {}
 
-  // URLRequestSimpleJob methods:
-  virtual bool GetData(std::string* mime_type,
-                       std::string* charset,
-                       std::string* data) const;
+  virtual void Start();
+  virtual bool GetMimeType(std::string* mime_type) const;
+  virtual bool GetCharset(std::string* charset);
+  virtual bool ReadRawData(net::IOBuffer* buf, int buf_size, int *bytes_read);
 
  private:
   ~ViewHttpCacheJob() {}
+
+  // Called when ViewCacheHelper completes the operation.
+  void OnIOComplete(int result);
+
+  std::string data_;
+  int data_offset_;
+  net::ViewCacheHelper cache_helper_;
+  net::CompletionCallbackImpl<ViewHttpCacheJob> callback_;
 };
 
-bool ViewHttpCacheJob::GetData(std::string* mime_type,
-                               std::string* charset,
-                               std::string* data) const {
+void ViewHttpCacheJob::Start() {
+  if (!request_)
+    return;
+
+  std::string cache_key =
+      request_->url().spec().substr(strlen(chrome::kNetworkViewCacheURL));
+
+  int rv;
+  if (cache_key.empty()) {
+    rv = cache_helper_.GetContentsHTML(request_->context(),
+                                       chrome::kNetworkViewCacheURL, &data_,
+                                       &callback_);
+  } else {
+    rv = cache_helper_.GetEntryInfoHTML(cache_key, request_->context(),
+                                        &data_, &callback_);
+  }
+
+  if (rv != net::ERR_IO_PENDING) {
+    // 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, &ViewHttpCacheJob::OnIOComplete, rv));
+  }
+}
+
+bool ViewHttpCacheJob::GetMimeType(std::string* mime_type) const {
   mime_type->assign("text/html");
-  charset->assign("UTF-8");
-
-  data->clear();
-
-  std::string cache_key;
-  cache_key =
-      request_->url().spec().substr(strlen(chrome::kNetworkViewCacheURL));
-  ViewCacheHelper::GetEntryInfoHTML(cache_key,
-                                    request_->context(),
-                                    chrome::kNetworkViewCacheURL,
-                                    data);
-
   return true;
 }
 
-}  // namespace
+bool ViewHttpCacheJob::GetCharset(std::string* charset) {
+  charset->assign("UTF-8");
+  return true;
+}
 
-// static
+bool ViewHttpCacheJob::ReadRawData(net::IOBuffer* buf, int buf_size,
+                                   int* bytes_read) {
+  DCHECK(bytes_read);
+  int remaining = static_cast<int>(data_.size()) - data_offset_;
+  if (buf_size > remaining)
+    buf_size = remaining;
+  memcpy(buf->data(), data_.data() + data_offset_, buf_size);
+  data_offset_ += buf_size;
+  *bytes_read = buf_size;
+  return true;
+}
+
+void ViewHttpCacheJob::OnIOComplete(int result) {
+  DCHECK_EQ(net::OK, result);
+
+  // Notify that the headers are complete.
+  NotifyHeadersComplete();
+}
+
+}  // namespace.
+
+// Static.
 bool ViewHttpCacheJobFactory::IsSupportedURL(const GURL& url) {
-  return StartsWithASCII(url.spec(),
-                         chrome::kNetworkViewCacheURL,
+  return StartsWithASCII(url.spec(), chrome::kNetworkViewCacheURL,
                          true /*case_sensitive*/);
 }
 
-// static
+// Static.
 URLRequestJob* ViewHttpCacheJobFactory::CreateJobForRequest(
     URLRequest* request) {
   return new ViewHttpCacheJob(request);
 }