Revert of Move fetching logic out of ApplicationManager, eliminate url mappings.

mojo/shell/network_fetcher.cc

Index: mojo/shell/network_fetcher.cc
diff --git a/mojo/shell/network_fetcher.cc b/mojo/shell/network_fetcher.cc
new file mode 100644
index 0000000000000000000000000000000000000000..c520477faf7247cf78f06341c4b73360c9c60c9b
--- /dev/null
+++ b/mojo/shell/network_fetcher.cc
@@ -0,0 +1,258 @@
+// Copyright 2015 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 "mojo/shell/network_fetcher.h"
+
+#include "base/bind.h"
+#include "base/command_line.h"
+#include "base/files/file.h"
+#include "base/files/file_path.h"
+#include "base/files/file_util.h"
+#include "base/message_loop/message_loop.h"
+#include "base/process/process.h"
+#include "base/stl_util.h"
+#include "base/strings/string_number_conversions.h"
+#include "base/strings/string_util.h"
+#include "base/strings/stringprintf.h"
+#include "base/strings/utf_string_conversions.h"
+#include "base/trace_event/trace_event.h"
+#include "crypto/secure_hash.h"
+#include "crypto/sha2.h"
+#include "mojo/common/common_type_converters.h"
+#include "mojo/common/data_pipe_utils.h"
+#include "mojo/common/url_type_converters.h"
+#include "mojo/services/network/public/interfaces/url_loader_factory.mojom.h"
+#include "mojo/shell/data_pipe_peek.h"
+#include "mojo/shell/switches.h"
+
+namespace mojo {
+namespace shell {
+
+NetworkFetcher::NetworkFetcher(bool disable_cache,
+                               mojo::URLRequestPtr request,
+                               URLLoaderFactory* url_loader_factory,
+                               const FetchCallback& loader_callback)
+    : Fetcher(loader_callback),
+      disable_cache_(false),
+      url_(request->url.To<GURL>()),
+      weak_ptr_factory_(this) {
+  StartNetworkRequest(request.Pass(), url_loader_factory);
+}
+
+NetworkFetcher::~NetworkFetcher() {
+}
+
+const GURL& NetworkFetcher::GetURL() const {
+  return url_;
+}
+
+GURL NetworkFetcher::GetRedirectURL() const {
+  if (!response_)
+    return GURL::EmptyGURL();
+
+  if (response_->redirect_url.is_null())
+    return GURL::EmptyGURL();
+
+  return GURL(response_->redirect_url);
+}
+
+GURL NetworkFetcher::GetRedirectReferer() const {
+  if (!response_)
+    return GURL::EmptyGURL();
+
+  if (response_->redirect_referrer.is_null())
+    return GURL::EmptyGURL();
+
+  return GURL(response_->redirect_referrer);
+}
+URLResponsePtr NetworkFetcher::AsURLResponse(base::TaskRunner* task_runner,
+                                             uint32_t skip) {
+  if (skip != 0) {
+    MojoResult result = ReadDataRaw(
+        response_->body.get(), nullptr, &skip,
+        MOJO_READ_DATA_FLAG_ALL_OR_NONE | MOJO_READ_DATA_FLAG_DISCARD);
+    DCHECK_EQ(result, MOJO_RESULT_OK);
+  }
+  return response_.Pass();
+}
+
+void NetworkFetcher::RecordCacheToURLMapping(const base::FilePath& path,
+                                             const GURL& url) {
+  // This is used to extract symbols on android.
+  // TODO(eseidel): All users of this log should move to using the map file.
+  VLOG(1) << "Caching mojo app " << url << " at " << path.value();
+
+  base::FilePath temp_dir;
+  base::GetTempDir(&temp_dir);
+  base::ProcessId pid = base::Process::Current().Pid();
+  std::string map_name = base::StringPrintf("mojo_shell.%d.maps", pid);
+  base::FilePath map_path = temp_dir.AppendASCII(map_name);
+
+  // TODO(eseidel): Paths or URLs with spaces will need quoting.
+  std::string map_entry =
+      base::StringPrintf("%s %s\n", path.value().c_str(), url.spec().c_str());
+  // TODO(eseidel): AppendToFile is missing O_CREAT, crbug.com/450696
+  if (!PathExists(map_path)) {
+    base::WriteFile(map_path, map_entry.data(),
+                    static_cast<int>(map_entry.length()));
+  } else {
+    base::AppendToFile(map_path, map_entry.data(),
+                       static_cast<int>(map_entry.length()));
+  }
+}
+
+// For remote debugging, GDB needs to be, a apriori, aware of the filename a
+// library will be loaded from. AppIds should be be both predictable and unique,
+// but any hash would work. Currently we use sha256 from crypto/secure_hash.h
+bool NetworkFetcher::ComputeAppId(const base::FilePath& path,
+                                  std::string* digest_string) {
+  scoped_ptr<crypto::SecureHash> ctx(
+      crypto::SecureHash::Create(crypto::SecureHash::SHA256));
+  base::File file(path, base::File::FLAG_OPEN | base::File::FLAG_READ);
+  if (!file.IsValid()) {
+    LOG(ERROR) << "Failed to open " << path.value() << " for computing AppId";
+    return false;
+  }
+  char buf[1024];
+  while (file.IsValid()) {
+    int bytes_read = file.ReadAtCurrentPos(buf, sizeof(buf));
+    if (bytes_read == 0)
+      break;
+    ctx->Update(buf, bytes_read);
+  }
+  if (!file.IsValid()) {
+    LOG(ERROR) << "Error reading " << path.value();
+    return false;
+  }
+  // The output is really a vector of unit8, we're cheating by using a string.
+  std::string output(crypto::kSHA256Length, 0);
+  ctx->Finish(string_as_array(&output), output.size());
+  output = base::HexEncode(output.c_str(), output.size());
+  // Using lowercase for compatiblity with sha256sum output.
+  *digest_string = base::ToLowerASCII(output);
+  return true;
+}
+
+bool NetworkFetcher::RenameToAppId(const GURL& url,
+                                   const base::FilePath& old_path,
+                                   base::FilePath* new_path) {
+  std::string app_id;
+  if (!ComputeAppId(old_path, &app_id))
+    return false;
+
+  // Using a hash of the url as a directory to prevent a race when the same
+  // bytes are downloaded from 2 different urls. In particular, if the same
+  // application is connected to twice concurrently with different query
+  // parameters, the directory will be different, which will prevent the
+  // collision.
+  std::string dirname = base::HexEncode(
+      crypto::SHA256HashString(url.spec()).data(), crypto::kSHA256Length);
+
+  base::FilePath temp_dir;
+  base::GetTempDir(&temp_dir);
+  base::FilePath app_dir = temp_dir.AppendASCII(dirname);
+  // The directory is leaked, because it can be reused at any time if the same
+  // application is downloaded. Deleting it would be racy. This is only
+  // happening when --predictable-app-filenames is used.
+  bool result = base::CreateDirectoryAndGetError(app_dir, nullptr);
+  DCHECK(result);
+  std::string unique_name = base::StringPrintf("%s.mojo", app_id.c_str());
+  *new_path = app_dir.AppendASCII(unique_name);
+  return base::Move(old_path, *new_path);
+}
+
+void NetworkFetcher::CopyCompleted(
+    base::Callback<void(const base::FilePath&, bool)> callback,
+    bool success) {
+  if (success) {
+    if (base::CommandLine::ForCurrentProcess()->HasSwitch(
+            switches::kPredictableAppFilenames)) {
+      // The copy completed, now move to $TMP/$APP_ID.mojo before the dlopen.
+      success = false;
+      base::FilePath new_path;
+      if (RenameToAppId(url_, path_, &new_path)) {
+        if (base::PathExists(new_path)) {
+          path_ = new_path;
+          success = true;
+        }
+      }
+    }
+  }
+
+  if (success)
+    RecordCacheToURLMapping(path_, url_);
+
+  base::MessageLoop::current()->PostTask(FROM_HERE,
+                                         base::Bind(callback, path_, success));
+}
+
+void NetworkFetcher::AsPath(
+    base::TaskRunner* task_runner,
+    base::Callback<void(const base::FilePath&, bool)> callback) {
+  if (!path_.empty() || !response_) {
+    base::MessageLoop::current()->PostTask(
+        FROM_HERE, base::Bind(callback, path_, base::PathExists(path_)));
+    return;
+  }
+
+  base::CreateTemporaryFile(&path_);
+  common::CopyToFile(response_->body.Pass(), path_, task_runner,
+                     base::Bind(&NetworkFetcher::CopyCompleted,
+                                weak_ptr_factory_.GetWeakPtr(), callback));
+}
+
+std::string NetworkFetcher::MimeType() {
+  return response_->mime_type;
+}
+
+bool NetworkFetcher::HasMojoMagic() {
+  std::string magic;
+  return BlockingPeekNBytes(response_->body.get(), &magic, strlen(kMojoMagic),
+                            kPeekTimeout) &&
+         magic == kMojoMagic;
+}
+
+bool NetworkFetcher::PeekFirstLine(std::string* line) {
+  return BlockingPeekLine(response_->body.get(), line, kMaxShebangLength,
+                          kPeekTimeout);
+}
+
+void NetworkFetcher::StartNetworkRequest(mojo::URLRequestPtr request,
+                                         URLLoaderFactory* url_loader_factory) {
+  TRACE_EVENT_ASYNC_BEGIN1("mojo_shell", "NetworkFetcher::NetworkRequest", this,
+                           "url", request->url.To<std::string>());
+  request->auto_follow_redirects = false;
+  request->bypass_cache = disable_cache_;
+
+  url_loader_factory->CreateURLLoader(GetProxy(&url_loader_));
+  url_loader_->Start(request.Pass(),
+                     base::Bind(&NetworkFetcher::OnLoadComplete,
+                                weak_ptr_factory_.GetWeakPtr()));
+}
+
+void NetworkFetcher::OnLoadComplete(URLResponsePtr response) {
+  TRACE_EVENT_ASYNC_END0("mojo_shell", "NetworkFetcher::NetworkRequest", this);
+  scoped_ptr<Fetcher> owner(this);
+  if (response->error) {
+    LOG(ERROR) << "Error (" << response->error->code << ": "
+               << response->error->description << ") while fetching "
+               << response->url;
+    loader_callback_.Run(nullptr);
+    return;
+  }
+
+  if (response->status_code >= 400 && response->status_code < 600) {
+    LOG(ERROR) << "Error (" << response->status_code << ": "
+               << response->status_line << "): "
+               << "while fetching " << response->url;
+    loader_callback_.Run(nullptr);
+    return;
+  }
+
+  response_ = response.Pass();
+  loader_callback_.Run(owner.Pass());
+}
+
+}  // namespace shell
+}  // namespace mojo