Initial implementation for CertNetFetcher.

net/cert/cert_net_fetcher.h

+// 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.
+
+#ifndef NET_CERT_CERT_NET_FETCHER_H_
+#define NET_CERT_CERT_NET_FETCHER_H_
+
+#include <vector>
+
+#include "base/callback.h"
+#include "net/base/net_errors.h"
+#include "net/base/net_export.h"
+
+class GURL;
+
+namespace net {
+
+class URLRequestContext;
+
+// CertNetFetcher is an asynchronous interface for fetching AIA URLs and CRL
+// URLs.
+//
+// -------------------------
+// Cancellation of requests
+// -------------------------
+//
+//  * Network requests started by the CertNetFetcher can be cancelled by
+//    deleting the Request object. Cancellation means the request's callback
+//    will no longer be invoked.
+//
+//  * If the CertNetFetcher is deleted then any outstanding
+//    requests are automatically cancelled.
+//
+//  * Cancelling a request within the execution of a callback is allowed.
+//
+//  * Deleting the CertNetFetcher from within the execution of a callback is
+//    allowed.
+//
+// -------------------------
+// Threading
+// -------------------------
+//
+// The CertNetFetcher is expected to be operated from a single thread, which has
+// an IO message loop. The URLRequestContext will be accessed from this same
+// thread, and callbacks will be posted to this message loop.
+//
+// For more details see the design document:
+//   https://docs.google.com/a/chromium.org/document/d/1CdS9YOnPdAyVZBJqHY7ZJ6tUlU71OCvX8kHnaVhf144/edit
+class NET_EXPORT CertNetFetcher {
+ public:
+  class Request {
+   public:
+    virtual ~Request() {}
+  };
+
+  // Callback invoked on request completion. If the Error is OK, then the
+  // vector contains the response bytes.
+  using FetchCallback =
+      base::Callback<void(Error, const std::vector<uint8_t>&)>;
+
+  // This value can be used in place of timeout or max size limits.
+  enum { DEFAULT = -1 };
+
+  CertNetFetcher() {}
+
+  // Deletion implicitly cancels any outstanding requests.
+  virtual ~CertNetFetcher() {}
+
+  // The Fetch*() methods start an asynchronous request which can be cancelled
+  // by deleting the returned Request. Here is the meaning of the common
+  // parameters:
+  //
+  //   * url -- The http:// URL to fetch.
+  //   * timeout_seconds -- The maximum allowed duration for the fetch job. If
+  //         this delay is exceeded then the request will fail. To use a default
+  //         timeout pass DEFAULT.
+  //   * max_response_bytes -- The maximum size of the response body. If this
+  //     size is exceeded then the request will fail. To use a default timeout
+  //     pass DEFAULT.
+  //   * callback -- The callback that will be invoked on completion of the job.
+
+  virtual WARN_UNUSED_RESULT scoped_ptr<Request> FetchCaIssuers(
+      const GURL& url,
+      int timeout_milliseconds,
+      int max_response_bytes,
+      const FetchCallback& callback) = 0;
+
+  virtual WARN_UNUSED_RESULT scoped_ptr<Request> FetchCrl(
+      const GURL& url,
+      int timeout_milliseconds,
+      int max_response_bytes,
+      const FetchCallback& callback) = 0;
+
+  virtual WARN_UNUSED_RESULT scoped_ptr<Request> FetchOcsp(
+      const GURL& url,
+      int timeout_milliseconds,
+      int max_response_bytes,
+      const FetchCallback& callback) = 0;
+
+ private:
+  DISALLOW_COPY_AND_ASSIGN(CertNetFetcher);
+};
+
+}  // namespace net
+
+#endif  // NET_CERT_NET_CERT_NET_FETCHER_H_