buffet: Added advanced error reporting
Created chromeos::Error class that encapsulates rich error
information from various system domains.
Swept GCD device registration, HTTP transport and utilities
to always return additional error information when the caller
requests it. This includes internal errors, general HTTP errors
as well as parsing and returning specific GCD and OAuth2 server
error responses.
Also fixed a number of existing linter warnings.
BUG=chromium:366709
TEST=All existing and new unit tests pass.
Change-Id: Ic01622a8efa3dc365ec106e595b09536818b9b23
Reviewed-on: https://chromium-review.googlesource.com/198772
Tested-by: Alex Vakulenko <avakulenko@chromium.org>
Reviewed-by: Christopher Wiley <wiley@chromium.org>
Commit-Queue: Alex Vakulenko <avakulenko@chromium.org>
diff --git a/buffet/error.h b/buffet/error.h
new file mode 100644
index 0000000..97c48ee
--- /dev/null
+++ b/buffet/error.h
@@ -0,0 +1,71 @@
+// Copyright 2014 The Chromium OS 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 BUFFET_ERROR_H_
+#define BUFFET_ERROR_H_
+
+#include <memory>
+#include <string>
+
+#include <base/basictypes.h>
+
+namespace chromeos {
+
+class Error; // Forward declaration.
+
+typedef std::unique_ptr<Error> ErrorPtr;
+
+class Error {
+ public:
+ virtual ~Error() = default;
+
+ // Creates an instance of Error class.
+ static ErrorPtr Create(const std::string& domain, const std::string& code,
+ const std::string& message);
+ static ErrorPtr Create(const std::string& domain, const std::string& code,
+ const std::string& message, ErrorPtr inner_error);
+ // If |error| is not nullptr, creates another instance of Error class,
+ // initializes it with specified arguments and adds it to the head of
+ // the error chain pointed to by |error|.
+ static void AddTo(ErrorPtr* error, const std::string& domain,
+ const std::string& code, const std::string& message);
+
+ // Returns the error domain, code and message
+ const std::string& GetDomain() const { return domain_; }
+ const std::string& GetCode() const { return code_; }
+ const std::string& GetMessage() const { return message_; }
+
+ // Checks if this or any of the inner error in the chain has the specified
+ // error domain.
+ bool HasDomain(const std::string& domain) const;
+ // Checks if this or any of the inner error in the chain matches the specified
+ // error domain and code.
+ bool HasError(const std::string& domain, const std::string& code) const;
+
+ // Gets a pointer to the inner error, if present. Returns nullptr otherwise.
+ const Error* GetInnerError() const { return inner_error_.get(); }
+
+ protected:
+ // Constructor is protected since this object is supposed to be
+ // created via the Create factory methods.
+ Error(const std::string& domain, const std::string& code,
+ const std::string& message, ErrorPtr inner_error);
+
+ // Error domain. The domain defines the scopes for error codes.
+ // Two errors with the same code but different domains are different errors.
+ std::string domain_;
+ // Error code. A unique error code identifier within the given domain.
+ std::string code_;
+ // Human-readable error message.
+ std::string message_;
+ // Pointer to inner error, if any. This forms a chain of errors.
+ ErrorPtr inner_error_;
+
+ private:
+ DISALLOW_COPY_AND_ASSIGN(Error);
+};
+
+} // namespace chromeos
+
+#endif // BUFFET_ERROR_H_
