[GCM] Unregistration request

google_apis/gcm/engine/unregistration_request.cc

+// Copyright 2014 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 "google_apis/gcm/engine/unregistration_request.h"
+
+#include "base/bind.h"
+#include "base/message_loop/message_loop.h"
+#include "base/metrics/histogram.h"
+#include "base/strings/string_number_conversions.h"
+#include "base/strings/string_piece.h"
+#include "base/values.h"
+#include "net/base/escape.h"
+#include "net/http/http_request_headers.h"
+#include "net/http/http_status_code.h"
+#include "net/url_request/url_fetcher.h"
+#include "net/url_request/url_request_context_getter.h"
+#include "net/url_request/url_request_status.h"
+#include "url/gurl.h"
+
+namespace gcm {
+
+namespace {
+
+const char kRegistrationURL[] =
+    "https://android.clients.google.com/c2dm/register3";
+const char kRequestContentType[] = "application/x-www-form-urlencoded";
+
+// Request constants.
+const char kAppIdKey[] = "app";
+const char kDeleteKey[] = "delete";
+const char kDeleteValue[] = "true";
+const char kDeviceIdKey[] = "device";
+const char kLoginHeader[] = "AidLogin";
+const char kUnregistrationCallerKey[] = "gcm_unreg_caller";
+// We are going to set the value to "false" in order to forcefully unregister
+// the application.
+const char kUnregistrationCallerValue[] = "false";
+
+// Response constants.
+const char kDeletedPrefix[] = "deleted=";
+const char kErrorPrefix[] = "Error=";
+const char kInvalidParameters[] = "INVALID_PARAMETERS";
+
+// Outcomens of the response parsing. Note that these enums are consumed by a
+// histogram, so ordering should not be modified.
+enum UnregistrationRequestStatus {
+  SUCCESS,                  // Unregistration completed successfully.
+  URL_FETCHING_FAILED,      // URL fetching failed.
+  NO_RESPONSE_BODY,         // No response body.
+  RESPONSE_PARSING_FAILED,  // Failed to parse a meaningful output from response
+                            // body.
+  INCORRECT_APP_ID,         // App ID returned by the fetcher does not match
+                            // request.
+  INVALID_PARAMETERS,       // Request parameters were invalid.
+  SERVICE_UNAVAILABLE,      // Unregistration service unavailable.
+  INTERNAL_SERVER_ERROR,    // Internal server error happened during request.
+  HTTP_NOT_OK,              // HTTP response code was not OK.
+  UNKNOWN_ERROR,            // Unknown error.
+  // NOTE: Always keep this entry at the end. Add new status types only
+  // immediately above this line. Make sure to update the corresponding
+  // histogram enum accordingly.
+  UNREGISTRATION_STATUS_COUNT,
+};
+
+void BuildFormEncoding(const std::string& key,
+                       const std::string& value,
+                       std::string* out) {
+  if (!out->empty())
+    out->append("&");
+  out->append(key + "=" + net::EscapeUrlEncodedData(value, true));
+}
+
+UnregistrationRequestStatus ParseFetcherResponse(const net::URLFetcher* source,
+                                                 std::string request_app_id) {
+  std::string response;

[jianli, 2014/02/14 18:36:18]

nit: better to move the definition of local variable right before its usage

[fgorski, 2014/02/14 18:48:42]

Done.

+  if (!source->GetStatus().is_success()) {
+    DVLOG(1) << "Fetcher failed";
+    return URL_FETCHING_FAILED;
+  }
+
+  net::HttpStatusCode response_status = static_cast<net::HttpStatusCode>(
+      source->GetResponseCode());
+  if (response_status != net::HTTP_OK) {
+    DVLOG(1) << "HTTP Status code is not OK, but: " << response_status;
+    if (response_status == net::HTTP_SERVICE_UNAVAILABLE)
+      return SERVICE_UNAVAILABLE;
+    else if (response_status == net::HTTP_INTERNAL_SERVER_ERROR)
+      return INTERNAL_SERVER_ERROR;
+    return HTTP_NOT_OK;
+  }
+
+  if (!source->GetResponseAsString(&response)) {
+    DVLOG(1) << "Failed to get response body.";
+    return NO_RESPONSE_BODY;
+  }
+
+  DVLOG(1) << "Parsing unregistration response.";
+  if (response.find(kDeletedPrefix) != std::string::npos) {
+    std::string app_id = response.substr(
+        response.find(kDeletedPrefix) + arraysize(kDeletedPrefix) - 1);
+    if (app_id == request_app_id)
+      return SUCCESS;
+    return INCORRECT_APP_ID;
+  }
+
+  if (response.find(kErrorPrefix) != std::string::npos) {
+    std::string error = response.substr(
+        response.find(kErrorPrefix) + arraysize(kErrorPrefix) - 1);
+    if (error == kInvalidParameters)
+      return INVALID_PARAMETERS;
+    return UNKNOWN_ERROR;
+  }
+
+  DVLOG(1) << "Not able to parse a meaningful output from response body."
+           << response;
+  return RESPONSE_PARSING_FAILED;
+}
+
+}  // namespace
+
+UnregistrationRequest::RequestInfo::RequestInfo(
+    uint64 android_id,
+    uint64 security_token,
+    const std::string& app_id)
+    : android_id(android_id),
+      security_token(security_token),
+      app_id(app_id) {
+}
+
+UnregistrationRequest::RequestInfo::~RequestInfo() {}
+
+UnregistrationRequest::UnregistrationRequest(
+    const RequestInfo& request_info,
+    const net::BackoffEntry::Policy& backoff_policy,
+    const UnregistrationCallback& callback,
+    scoped_refptr<net::URLRequestContextGetter> request_context_getter)
+    : callback_(callback),
+      request_info_(request_info),
+      backoff_entry_(&backoff_policy),
+      request_context_getter_(request_context_getter),
+      weak_ptr_factory_(this) {
+}
+
+UnregistrationRequest::~UnregistrationRequest() {}
+
+void UnregistrationRequest::Start() {
+  DCHECK(!callback_.is_null());
+  DCHECK(request_info_.android_id != 0UL);
+  DCHECK(request_info_.security_token != 0UL);
+  DCHECK(!url_fetcher_.get());
+
+  url_fetcher_.reset(net::URLFetcher::Create(
+      GURL(kRegistrationURL), net::URLFetcher::DELETE_REQUEST, this));
+  url_fetcher_->SetRequestContext(request_context_getter_);
+
+  std::string android_id = base::Uint64ToString(request_info_.android_id);
+  std::string auth_header =
+      std::string(kLoginHeader) + " " + android_id + ":" +
+      base::Uint64ToString(request_info_.security_token);
+  net::HttpRequestHeaders headers;
+  headers.SetHeader(net::HttpRequestHeaders::kAuthorization, auth_header);
+  headers.SetHeader(kAppIdKey, request_info_.app_id);
+  url_fetcher_->SetExtraRequestHeaders(headers.ToString());
+
+  std::string body;
+  BuildFormEncoding(kAppIdKey, request_info_.app_id, &body);
+  BuildFormEncoding(kDeviceIdKey, android_id, &body);
+  BuildFormEncoding(kDeleteKey, kDeleteValue, &body);
+  BuildFormEncoding(kUnregistrationCallerKey,
+                    kUnregistrationCallerValue,
+                    &body);
+
+  DVLOG(1) << "Unregistration request: " << body;
+  url_fetcher_->SetUploadData(kRequestContentType, body);
+
+  DVLOG(1) << "Performing unregistration for: " << request_info_.app_id;
+  url_fetcher_->Start();
+}
+
+void UnregistrationRequest::RetryWithBackoff(bool update_backoff) {
+  if (update_backoff) {
+    url_fetcher_.reset();
+    backoff_entry_.InformOfRequest(false);
+  }
+
+  if (backoff_entry_.ShouldRejectRequest()) {
+    DVLOG(1) << "Delaying GCM unregistration of app: "
+             << request_info_.app_id << ", for "
+             << backoff_entry_.GetTimeUntilRelease().InMilliseconds()
+             << " milliseconds.";
+    base::MessageLoop::current()->PostDelayedTask(
+        FROM_HERE,
+        base::Bind(&UnregistrationRequest::RetryWithBackoff,
+                   weak_ptr_factory_.GetWeakPtr(),
+                   false),
+        backoff_entry_.GetTimeUntilRelease());
+    return;
+  }
+
+  Start();
+}
+
+void UnregistrationRequest::OnURLFetchComplete(const net::URLFetcher* source) {
+  UnregistrationRequestStatus status =
+      ParseFetcherResponse(source, request_info_.app_id);
+
+  DVLOG(1) << "UnregistrationRequestStauts: " << status;
+  UMA_HISTOGRAM_ENUMERATION("GCM.UnregistrationRequestStatus",
+                            status,
+                            UNREGISTRATION_STATUS_COUNT);
+
+  if (status == URL_FETCHING_FAILED ||
+      status == SERVICE_UNAVAILABLE ||
+      status == INTERNAL_SERVER_ERROR ||
+      status == INCORRECT_APP_ID ||
+      status == RESPONSE_PARSING_FAILED) {
+    RetryWithBackoff(true);
+  } else {
+    // status == SUCCESS || HTTP_NOT_OK || NO_RESPONSE_BODY ||
+    // INVALID_PARAMETERS || UNKNOWN_ERROR
+    callback_.Run(status == SUCCESS);
+  }
+}
+
+}  // namespace gcm