Quirks Client for downloading and providing display profiles

components/quirks/quirks_client.cc

+// Copyright 2016 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 "components/quirks/quirks_client.h"
+
+#include "base/base64.h"
+#include "base/files/file_util.h"
+#include "base/json/json_reader.h"
+#include "base/strings/stringprintf.h"
+#include "base/task_runner_util.h"
+#include "base/thread_task_runner_handle.h"
+#include "base/threading/thread_restrictions.h"
+#include "components/prefs/scoped_user_pref_update.h"
+#include "components/version_info/version_info.h"
+#include "net/base/load_flags.h"
+#include "net/http/http_status_code.h"
+#include "net/url_request/url_fetcher.h"
+#include "net/url_request/url_request_context_getter.h"
+
+namespace quirks {
+
+namespace {
+
+const char kQuirksUrlFormat[] =
+    "https://qa-quirksserver-pa.sandbox.googleapis.com/v2/display/%s/clients"
+    "/chromeos/M%d";
+
+const net::BackoffEntry::Policy kDefaultBackoffPolicy = {
+    1,                // Initial errors before applying backoff
+    10000,            // 10 seconds.
+    2,                // Factor by which the waiting time will be multiplied.
+    0,                // Random fuzzing percentage.
+    1000 * 3600 * 6,  // Max wait between requests = 6 hours.
+    -1,               // Don't discard entry.
+    true,             // Use initial delay after first error.
+};
+
+bool WriteIccFile(const base::FilePath file_path, const std::string& data) {
+  base::ThreadRestrictions::AssertIOAllowed();

[Bernhard Bauer, 2016/03/17 17:42:25]

Doesn't base::WriteFile already do this? Basically, the idea with thread
restrictions is that they're checked as far down the call stack as possible,
i.e. right before we call into code we don't control anymore.

[Greg Levin, 2016/03/18 00:35:46]

Got it, thanks.  I wasn't sure how much they were programmatic checks, and how
much they were just annotations.

+  int bytes_written = base::WriteFile(file_path, data.data(), data.length());
+  if (bytes_written == -1)
+    LOG(ERROR) << "Write failed: " << file_path.value() << ", err = " << errno;
+  else
+    VLOG(1) << bytes_written << "bytes written to: " << file_path.value();
+
+  return (bytes_written != -1);
+}
+
+}  // namespace
+
+////////////////////////////////////////////////////////////////////////////////
+// QuirksClient
+
+QuirksClient::QuirksClient(int64_t product_id,
+                           const RequestFinishedCallback& on_request_finished,
+                           QuirksManager* manager)
+    : product_id_(product_id),
+      on_request_finished_(on_request_finished),
+      manager_(manager),
+      icc_path_(
+          manager->delegate()->GetDownloadDisplayProfileDirectory().Append(
+              IdToFileName(product_id))),
+      backoff_entry_(&kDefaultBackoffPolicy),
+      weak_ptr_factory_(this) {}
+
+QuirksClient::~QuirksClient() {}
+
+void QuirksClient::StartDownload() {
+  DCHECK(base::ThreadTaskRunnerHandle::IsSet());
+
+  // URL of icc file on Quirks Server.
+  int major_version = atoi(version_info::GetVersionNumber().c_str());
+  std::string url = base::StringPrintf(
+      kQuirksUrlFormat, IdToHexString(product_id_).c_str(), major_version);
+
+  VLOG(2) << "Preparing to download\n  " << url << "\nto file "
+          << icc_path_.value();
+
+  url += "?key=";
+  url += manager_->delegate()->GetApiKey();
+
+  url_fetcher_ = manager_->CreateURLFetcher(url, this);
+  url_fetcher_->SetRequestContext(manager_->url_context_getter());
+  url_fetcher_->SetLoadFlags(net::LOAD_BYPASS_CACHE | net::LOAD_DISABLE_CACHE |
+                             net::LOAD_DO_NOT_SAVE_COOKIES |
+                             net::LOAD_DO_NOT_SEND_COOKIES |
+                             net::LOAD_DO_NOT_SEND_AUTH_DATA);
+  url_fetcher_->Start();
+}
+
+void QuirksClient::OnURLFetchComplete(const net::URLFetcher* source) {
+  DCHECK(base::ThreadTaskRunnerHandle::IsSet());
+  DCHECK_EQ(url_fetcher_.get(), source);
+
+  const int HTTP_INTERNAL_SERVER_ERROR_LAST =
+      net::HTTP_INTERNAL_SERVER_ERROR + 99;
+  const net::URLRequestStatus status = source->GetStatus();
+  const int response_code = source->GetResponseCode();
+  const bool server_error = !status.is_success() ||
+                            (response_code >= net::HTTP_INTERNAL_SERVER_ERROR &&
+                             response_code <= HTTP_INTERNAL_SERVER_ERROR_LAST);
+
+  VLOG(2) << "QuirksClient::OnURLFetchComplete():"
+          << "  status=" << status.status()
+          << ",  response_code=" << response_code
+          << ",  server_error=" << server_error;
+
+  if (response_code == net::HTTP_NOT_FOUND) {
+    VLOG(1) << IdToFileName(product_id_) << " not found on Quirks server.";
+    Shutdown(false);
+    return;
+  }
+
+  if (server_error) {
+    url_fetcher_.reset();
+    Retry();
+    return;
+  }
+
+  std::string response;
+  url_fetcher_->GetResponseAsString(&response);
+  VLOG(2) << "Quirks server response:\n" << response;
+
+  // Parse response data and write to file on file thread.
+  std::string data;
+  if (!ParseResult(response, &data)) {
+    Shutdown(false);
+    return;
+  }
+
+  base::PostTaskAndReplyWithResult(
+      manager_->blocking_pool(), FROM_HERE,
+      base::Bind(&WriteIccFile, icc_path_, data),
+      base::Bind(&QuirksClient::Shutdown, weak_ptr_factory_.GetWeakPtr()));
+}
+
+void QuirksClient::Shutdown(bool success) {
+  DCHECK(base::ThreadTaskRunnerHandle::IsSet());
+  on_request_finished_.Run(success ? icc_path_ : base::FilePath(), true);
+  manager_->ClientFinished(this);
+}
+
+void QuirksClient::Retry() {
+  DCHECK(base::ThreadTaskRunnerHandle::IsSet());
+  backoff_entry_.InformOfRequest(false);
+  const base::TimeDelta delay = backoff_entry_.GetTimeUntilRelease();
+
+  VLOG(1) << "Schedule next Quirks download attempt in " << delay.InSecondsF()
+          << " seconds (retry = " << backoff_entry_.failure_count() << ").";
+  request_scheduled_.Start(FROM_HERE, delay, this,
+                           &QuirksClient::StartDownload);
+}
+
+bool QuirksClient::ParseResult(const std::string& result, std::string* data) {
+  std::string data64;
+  const base::DictionaryValue* dict;
+  scoped_ptr<base::Value> json = base::JSONReader::Read(result);
+  if (!json || !json->GetAsDictionary(&dict) ||
+      !dict->GetString("icc", &data64)) {
+    VLOG(1) << "Failed to parse JSON icc data";
+    return false;
+  }
+
+  if (!base::Base64Decode(data64, data)) {
+    VLOG(1) << "Failed to decode Base64 icc data";
+    return false;
+  }
+
+  return true;
+}
+
+}  // namespace quirks