content/browser/net/view_http_cache_job_factory.cc

   1 // Copyright (c) 2012 The Chromium Authors. All rights reserved.
   2 // Use of this source code is governed by a BSD-style license that can be
   3 // found in the LICENSE file.
   4
   5 #include "content/browser/net/view_http_cache_job_factory.h"
   6
   7 #include "base/bind.h"
   8 #include "base/bind_helpers.h"
   9 #include "base/callback.h"
  10 #include "base/compiler_specific.h"
  11 #include "base/memory/weak_ptr.h"
  12 #include "base/message_loop/message_loop.h"
  13 #include "base/strings/string_util.h"
  14 #include "content/public/common/url_constants.h"
  15 #include "net/base/completion_callback.h"
  16 #include "net/base/net_errors.h"
  17 #include "net/url_request/url_request.h"
  18 #include "net/url_request/url_request_simple_job.h"
  19 #include "net/url_request/view_cache_helper.h"
  20
  21 namespace content {
  22 namespace {
  23
  24 // A job subclass that dumps an HTTP cache entry.
  25 class ViewHttpCacheJob : public net::URLRequestJob {
  26  public:
  27   ViewHttpCacheJob(net::URLRequest* request,
  28                    net::NetworkDelegate* network_delegate)
  29       : net::URLRequestJob(request, network_delegate),
  30         core_(new Core),
  31         weak_factory_(this),
  32         callback_(base::Bind(&ViewHttpCacheJob::OnStartCompleted,
  33                              base::Unretained(this))) {
  34   }
  35
  36   // net::URLRequestJob implementation.
  37   virtual void Start() OVERRIDE;
  38   virtual void Kill() OVERRIDE;
  39   virtual bool GetMimeType(std::string* mime_type) const OVERRIDE{
  40     return core_->GetMimeType(mime_type);
  41   }
  42   virtual bool GetCharset(std::string* charset) OVERRIDE{
  43     return core_->GetCharset(charset);
  44   }
  45   virtual bool ReadRawData(net::IOBuffer* buf,
  46                            int buf_size, int *bytes_read) OVERRIDE{
  47     return core_->ReadRawData(buf, buf_size, bytes_read);
  48   }
  49
  50  private:
  51   class Core : public base::RefCounted<Core> {
  52    public:
  53     Core()
  54         : data_offset_(0),
  55           callback_(base::Bind(&Core::OnIOComplete, this)) {
  56     }
  57
  58     int Start(const net::URLRequest& request, const base::Closure& callback);
  59
  60     // Prevents it from invoking its callback. It will self-delete.
  61     void Orphan() {
  62       user_callback_.Reset();
  63     }
  64
  65     bool GetMimeType(std::string* mime_type) const;
  66     bool GetCharset(std::string* charset);
  67     bool ReadRawData(net::IOBuffer* buf, int buf_size, int *bytes_read);
  68
  69    private:
  70     friend class base::RefCounted<Core>;
  71
  72     ~Core() {}
  73
  74     // Called when ViewCacheHelper completes the operation.
  75     void OnIOComplete(int result);
  76
  77     std::string data_;
  78     int data_offset_;
  79     net::ViewCacheHelper cache_helper_;
  80     net::CompletionCallback callback_;
  81     base::Closure user_callback_;
  82
  83     DISALLOW_COPY_AND_ASSIGN(Core);
  84   };
  85
  86   virtual ~ViewHttpCacheJob() {}
  87
  88   void StartAsync();
  89   void OnStartCompleted();
  90
  91   scoped_refptr<Core> core_;
  92   base::WeakPtrFactory<ViewHttpCacheJob> weak_factory_;
  93   base::Closure callback_;
  94
  95   DISALLOW_COPY_AND_ASSIGN(ViewHttpCacheJob);
  96 };
  97
  98 void ViewHttpCacheJob::Start() {
  99   base::MessageLoop::current()->PostTask(
 100       FROM_HERE,
 101       base::Bind(&ViewHttpCacheJob::StartAsync, weak_factory_.GetWeakPtr()));
 102 }
 103
 104 void ViewHttpCacheJob::Kill() {
 105   weak_factory_.InvalidateWeakPtrs();
 106   if (core_.get()) {
 107     core_->Orphan();
 108     core_ = NULL;
 109   }
 110   net::URLRequestJob::Kill();
 111 }
 112
 113 void ViewHttpCacheJob::StartAsync() {
 114   DCHECK(request());
 115
 116   if (!request())
 117     return;
 118
 119   int rv = core_->Start(*request(), callback_);
 120   if (rv != net::ERR_IO_PENDING) {
 121     DCHECK_EQ(net::OK, rv);
 122     OnStartCompleted();
 123   }
 124 }
 125
 126 void ViewHttpCacheJob::OnStartCompleted() {
 127   NotifyHeadersComplete();
 128 }
 129
 130 int ViewHttpCacheJob::Core::Start(const net::URLRequest& request,
 131                                   const base::Closure& callback) {
 132   DCHECK(!callback.is_null());
 133   DCHECK(user_callback_.is_null());
 134
 135   AddRef();  // Released on OnIOComplete().
 136   std::string cache_key =
 137       request.url().spec().substr(strlen(kChromeUINetworkViewCacheURL));
 138
 139   int rv;
 140   if (cache_key.empty()) {
 141     rv = cache_helper_.GetContentsHTML(request.context(),
 142                                        kChromeUINetworkViewCacheURL,
 143                                        &data_, callback_);
 144   } else {
 145     rv = cache_helper_.GetEntryInfoHTML(cache_key, request.context(),
 146                                         &data_, callback_);
 147   }
 148
 149   if (rv == net::ERR_IO_PENDING)
 150     user_callback_ = callback;
 151
 152   return rv;
 153 }
 154
 155 bool ViewHttpCacheJob::Core::GetMimeType(std::string* mime_type) const {
 156   mime_type->assign("text/html");
 157   return true;
 158 }
 159
 160 bool ViewHttpCacheJob::Core::GetCharset(std::string* charset) {
 161   charset->assign("UTF-8");
 162   return true;
 163 }
 164
 165 bool ViewHttpCacheJob::Core::ReadRawData(net::IOBuffer* buf,
 166                                          int buf_size,
 167                                          int* bytes_read) {
 168   DCHECK(bytes_read);
 169   int remaining = static_cast<int>(data_.size()) - data_offset_;
 170   if (buf_size > remaining)
 171     buf_size = remaining;
 172   memcpy(buf->data(), data_.data() + data_offset_, buf_size);
 173   data_offset_ += buf_size;
 174   *bytes_read = buf_size;
 175   return true;
 176 }
 177
 178 void ViewHttpCacheJob::Core::OnIOComplete(int result) {
 179   DCHECK_EQ(net::OK, result);
 180
 181   if (!user_callback_.is_null())
 182     user_callback_.Run();
 183
 184   // We may be holding the last reference to this job. Do not access |this|
 185   // after Release().
 186   Release();  // Acquired on Start().
 187 }
 188
 189 }  // namespace.
 190
 191 // Static.
 192 bool ViewHttpCacheJobFactory::IsSupportedURL(const GURL& url) {
 193   return url.SchemeIs(kChromeUIScheme) &&
 194          url.host() == kChromeUINetworkViewCacheHost;
 195 }
 196
 197 // Static.
 198 net::URLRequestJob* ViewHttpCacheJobFactory::CreateJobForRequest(
 199     net::URLRequest* request, net::NetworkDelegate* network_delegate) {
 200   return new ViewHttpCacheJob(request, network_delegate);
 201 }
 202
 203 }  // namespace content