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Diffstat (limited to 'indra/newview/llhttpretrypolicy.h')
-rwxr-xr-x | indra/newview/llhttpretrypolicy.h | 98 |
1 files changed, 98 insertions, 0 deletions
diff --git a/indra/newview/llhttpretrypolicy.h b/indra/newview/llhttpretrypolicy.h new file mode 100755 index 0000000000..cf79e0b401 --- /dev/null +++ b/indra/newview/llhttpretrypolicy.h @@ -0,0 +1,98 @@ +/** + * @file file llhttpretrypolicy.h + * @brief declarations for http retry policy class. + * + * $LicenseInfo:firstyear=2013&license=viewerlgpl$ + * Second Life Viewer Source Code + * Copyright (C) 2013, Linden Research, Inc. + * + * This library is free software; you can redistribute it and/or + * modify it under the terms of the GNU Lesser General Public + * License as published by the Free Software Foundation; + * version 2.1 of the License only. + * + * This library is distributed in the hope that it will be useful, + * but WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU + * Lesser General Public License for more details. + * + * You should have received a copy of the GNU Lesser General Public + * License along with this library; if not, write to the Free Software + * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA + * + * Linden Research, Inc., 945 Battery Street, San Francisco, CA 94111 USA + * $/LicenseInfo$ + */ + +#ifndef LL_RETRYPOLICY_H +#define LL_RETRYPOLICY_H + +#include "lltimer.h" +#include "llthread.h" + +#include "llhttpconstants.h" + +// For compatibility with new core http lib. +#include "httpresponse.h" +#include "httpheaders.h" + +// This is intended for use with HTTP Clients/Responders, but is not +// specifically coupled with those classes. +class LLHTTPRetryPolicy: public LLThreadSafeRefCount +{ +public: + LLHTTPRetryPolicy() {} + + virtual ~LLHTTPRetryPolicy() {} + // Call after a sucess to reset retry state. + + virtual void onSuccess() = 0; + // Call once after an HTTP failure to update state. + virtual void onFailure(S32 status, const LLSD& headers) = 0; + + virtual void onFailure(const LLCore::HttpResponse *response) = 0; + + virtual bool shouldRetry(F32& seconds_to_wait) const = 0; + + virtual void reset() = 0; +}; + +// Very general policy with geometric back-off after failures, +// up to a maximum delay, and maximum number of retries. +class LLAdaptiveRetryPolicy: public LLHTTPRetryPolicy +{ +public: + LLAdaptiveRetryPolicy(F32 min_delay, F32 max_delay, F32 backoff_factor, U32 max_retries, bool retry_on_4xx = false); + + // virtual + void onSuccess(); + + void reset(); + + // virtual + void onFailure(S32 status, const LLSD& headers); + // virtual + void onFailure(const LLCore::HttpResponse *response); + // virtual + bool shouldRetry(F32& seconds_to_wait) const; + +protected: + void init(); + bool getRetryAfter(const LLSD& headers, F32& retry_header_time); + bool getRetryAfter(const LLCore::HttpHeaders *headers, F32& retry_header_time); + void onFailureCommon(S32 status, bool has_retry_header_time, F32 retry_header_time); + +private: + + const F32 mMinDelay; // delay never less than this value + const F32 mMaxDelay; // delay never exceeds this value + const F32 mBackoffFactor; // delay increases by this factor after each retry, up to mMaxDelay. + const U32 mMaxRetries; // maximum number of times shouldRetry will return true. + F32 mDelay; // current default delay. + U32 mRetryCount; // number of times shouldRetry has been called. + LLTimer mRetryTimer; // time until next retry. + bool mShouldRetry; // Becomes false after too many retries, or the wrong sort of status received, etc. + bool mRetryOn4xx; // Normally only retry on 5xx server errors. +}; + +#endif |