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/location.h"
  12 #include "base/memory/weak_ptr.h"
  13 #include "base/single_thread_task_runner.h"
  14 #include "base/strings/string_util.h"
  15 #include "base/thread_task_runner_handle.h"
  16 #include "content/public/common/url_constants.h"
  17 #include "net/base/completion_callback.h"
  18 #include "net/base/net_errors.h"
  19 #include "net/url_request/url_request.h"
  20 #include "net/url_request/url_request_simple_job.h"
  21 #include "net/url_request/view_cache_helper.h"
  22
  23 namespace content {
  24 namespace {
  25
  26 // A job subclass that dumps an HTTP cache entry.
  27 class ViewHttpCacheJob : public net::URLRequestJob {
  28  public:
  29   ViewHttpCacheJob(net::URLRequest* request,
  30                    net::NetworkDelegate* network_delegate)
  31       : net::URLRequestJob(request, network_delegate),
  32         core_(new Core),
  33         callback_(base::Bind(&ViewHttpCacheJob::OnStartCompleted,
  34                              base::Unretained(this))),
  35         weak_factory_(this) {
  36   }
  37
  38   // net::URLRequestJob implementation.
  39   void Start() override;
  40   void Kill() override;
  41   bool GetMimeType(std::string* mime_type) const override {
  42     return core_->GetMimeType(mime_type);
  43   }
  44   bool GetCharset(std::string* charset) override {
  45     return core_->GetCharset(charset);
  46   }
  47   bool ReadRawData(net::IOBuffer* buf, int buf_size, int* bytes_read) override {
  48     return core_->ReadRawData(buf, buf_size, bytes_read);
  49   }
  50
  51  private:
  52   class Core : public base::RefCounted<Core> {
  53    public:
  54     Core()
  55         : data_offset_(0),
  56           callback_(base::Bind(&Core::OnIOComplete, this)) {
  57     }
  58
  59     int Start(const net::URLRequest& request, const base::Closure& callback);
  60
  61     // Prevents it from invoking its callback. It will self-delete.
  62     void Orphan() {
  63       user_callback_.Reset();
  64     }
  65
  66     bool GetMimeType(std::string* mime_type) const;
  67     bool GetCharset(std::string* charset);
  68     bool ReadRawData(net::IOBuffer* buf, int buf_size, int *bytes_read);
  69
  70    private:
  71     friend class base::RefCounted<Core>;
  72
  73     ~Core() {}
  74
  75     // Called when ViewCacheHelper completes the operation.
  76     void OnIOComplete(int result);
  77
  78     std::string data_;
  79     int data_offset_;
  80     net::ViewCacheHelper cache_helper_;
  81     net::CompletionCallback callback_;
  82     base::Closure user_callback_;
  83
  84     DISALLOW_COPY_AND_ASSIGN(Core);
  85   };
  86
  87   ~ViewHttpCacheJob() override {}
  88
  89   void StartAsync();
  90   void OnStartCompleted();
  91
  92   scoped_refptr<Core> core_;
  93   base::Closure callback_;
  94
  95   base::WeakPtrFactory<ViewHttpCacheJob> weak_factory_;
  96
  97   DISALLOW_COPY_AND_ASSIGN(ViewHttpCacheJob);
  98 };
  99
 100 void ViewHttpCacheJob::Start() {
 101   base::ThreadTaskRunnerHandle::Get()->PostTask(
 102       FROM_HERE,
 103       base::Bind(&ViewHttpCacheJob::StartAsync, weak_factory_.GetWeakPtr()));
 104 }
 105
 106 void ViewHttpCacheJob::Kill() {
 107   weak_factory_.InvalidateWeakPtrs();
 108   if (core_.get()) {
 109     core_->Orphan();
 110     core_ = NULL;
 111   }
 112   net::URLRequestJob::Kill();
 113 }
 114
 115 void ViewHttpCacheJob::StartAsync() {
 116   DCHECK(request());
 117
 118   if (!request())
 119     return;
 120
 121   int rv = core_->Start(*request(), callback_);
 122   if (rv != net::ERR_IO_PENDING) {
 123     DCHECK_EQ(net::OK, rv);
 124     OnStartCompleted();
 125   }
 126 }
 127
 128 void ViewHttpCacheJob::OnStartCompleted() {
 129   NotifyHeadersComplete();
 130 }
 131
 132 int ViewHttpCacheJob::Core::Start(const net::URLRequest& request,
 133                                   const base::Closure& callback) {
 134   DCHECK(!callback.is_null());
 135   DCHECK(user_callback_.is_null());
 136
 137   AddRef();  // Released on OnIOComplete().
 138   std::string cache_key =
 139       request.url().spec().substr(strlen(kChromeUINetworkViewCacheURL));
 140
 141   int rv;
 142   if (cache_key.empty()) {
 143     rv = cache_helper_.GetContentsHTML(request.context(),
 144                                        kChromeUINetworkViewCacheURL,
 145                                        &data_, callback_);
 146   } else {
 147     rv = cache_helper_.GetEntryInfoHTML(cache_key, request.context(),
 148                                         &data_, callback_);
 149   }
 150
 151   if (rv == net::ERR_IO_PENDING)
 152     user_callback_ = callback;
 153
 154   return rv;
 155 }
 156
 157 bool ViewHttpCacheJob::Core::GetMimeType(std::string* mime_type) const {
 158   mime_type->assign("text/html");
 159   return true;
 160 }
 161
 162 bool ViewHttpCacheJob::Core::GetCharset(std::string* charset) {
 163   charset->assign("UTF-8");
 164   return true;
 165 }
 166
 167 bool ViewHttpCacheJob::Core::ReadRawData(net::IOBuffer* buf,
 168                                          int buf_size,
 169                                          int* bytes_read) {
 170   DCHECK(bytes_read);
 171   int remaining = static_cast<int>(data_.size()) - data_offset_;
 172   if (buf_size > remaining)
 173     buf_size = remaining;
 174   memcpy(buf->data(), data_.data() + data_offset_, buf_size);
 175   data_offset_ += buf_size;
 176   *bytes_read = buf_size;
 177   return true;
 178 }
 179
 180 void ViewHttpCacheJob::Core::OnIOComplete(int result) {
 181   DCHECK_EQ(net::OK, result);
 182
 183   if (!user_callback_.is_null())
 184     user_callback_.Run();
 185
 186   // We may be holding the last reference to this job. Do not access |this|
 187   // after Release().
 188   Release();  // Acquired on Start().
 189 }
 190
 191 }  // namespace.
 192
 193 // Static.
 194 bool ViewHttpCacheJobFactory::IsSupportedURL(const GURL& url) {
 195   return url.SchemeIs(kChromeUIScheme) &&
 196          url.host() == kChromeUINetworkViewCacheHost;
 197 }
 198
 199 // Static.
 200 net::URLRequestJob* ViewHttpCacheJobFactory::CreateJobForRequest(
 201     net::URLRequest* request, net::NetworkDelegate* network_delegate) {
 202   return new ViewHttpCacheJob(request, network_delegate);
 203 }
 204
 205 }  // namespace content