Initial AISv3 merge. New HTTP messages not plugged in yet.

indra/newview/llhttpretrypolicy.cpp

@@ -0,0 +1,155 @@
+/** 
+ * @file llhttpretrypolicy.h
+ * @brief Header for a retry policy class intended for use with http responders.
+ *
+ * $LicenseInfo:firstyear=2013&license=viewerlgpl$
+ * 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
+ * $/LicenseInfo$
+ */
+
+#include "llviewerprecompiledheaders.h"
+
+#include "llhttpretrypolicy.h"
+#include "llhttpstatuscodes.h"
+#include "aihttpheaders.h"
+
+// for curl_getdate() (apparently parsing RFC 1123 dates is hard)
+#include <curl/curl.h>
+
+// Parses 'Retry-After' header contents and returns seconds until retry should occur.
+bool getSecondsUntilRetryAfter(const std::string& retry_after, F32& seconds_to_wait)
+{
+	// *TODO:  This needs testing!   Not in use yet.
+	// Examples of Retry-After headers:
+	// Retry-After: Fri, 31 Dec 1999 23:59:59 GMT
+	// Retry-After: 120
+
+	// Check for number of seconds version, first:
+	char* end = 0;
+	// Parse as double
+	double seconds = std::strtod(retry_after.c_str(), &end);
+	if (end != 0 && *end == 0)
+	{
+		// Successful parse
+		seconds_to_wait = (F32)seconds;
+		return true;
+	}
+
+	// Parse rfc1123 date.
+	time_t date = curl_getdate(retry_after.c_str(), NULL);
+	if (-1 == date) return false;
+
+	seconds_to_wait = (F64)date - LLTimer::getTotalSeconds();
+
+	return true;
+}
+
+LLAdaptiveRetryPolicy::LLAdaptiveRetryPolicy(F32 min_delay, F32 max_delay, F32 backoff_factor, U32 max_retries, bool retry_on_4xx):
+	mMinDelay(min_delay),
+	mMaxDelay(max_delay),
+	mBackoffFactor(backoff_factor),
+	mMaxRetries(max_retries),
+	mRetryOn4xx(retry_on_4xx)
+{
+	init();
+}
+
+void LLAdaptiveRetryPolicy::init()
+{
+	mDelay = mMinDelay;
+	mRetryCount = 0;
+	mShouldRetry = true;
+}
+
+void LLAdaptiveRetryPolicy::reset()
+{
+	init();
+}
+
+bool LLAdaptiveRetryPolicy::getRetryAfter(const AIHTTPReceivedHeaders& headers, F32& retry_header_time)
+{
+	AIHTTPReceivedHeaders::range_type results;
+	return headers.getValues("retry-after", results) && getSecondsUntilRetryAfter(results.first->second, retry_header_time);
+}
+
+void LLAdaptiveRetryPolicy::onSuccess()
+{
+	init();
+}
+
+void LLAdaptiveRetryPolicy::onFailure(S32 status, const AIHTTPReceivedHeaders& headers)
+{
+	F32 retry_header_time;
+	bool has_retry_header_time = getRetryAfter(headers,retry_header_time);
+	onFailureCommon(status, has_retry_header_time, retry_header_time);
+}
+  
+
+void LLAdaptiveRetryPolicy::onFailureCommon(S32 status, bool has_retry_header_time, F32 retry_header_time)
+{
+	if (!mShouldRetry)
+	{
+		LL_INFOS() << "keep on failing" << LL_ENDL;
+		return;
+	}
+	if (mRetryCount > 0)
+	{
+		mDelay = llclamp(mDelay*mBackoffFactor,mMinDelay,mMaxDelay);
+	}
+	// Honor server Retry-After header.
+	// Status 503 may ask us to wait for a certain amount of time before retrying.
+	F32 wait_time = mDelay;
+	if (has_retry_header_time)
+	{
+		wait_time = retry_header_time;
+	}
+
+	if (mRetryCount>=mMaxRetries)
+	{
+		LL_INFOS() << "Too many retries " << mRetryCount << ", will not retry" << LL_ENDL;
+		mShouldRetry = false;
+	}
+
+	if (!mRetryOn4xx && !(status == HTTP_INTERNAL_ERROR_OTHER || ((500 <= status) && (status < 600))))
+	{
+		LL_INFOS() << "Non-server error " << status << ", will not retry" << LL_ENDL;
+		mShouldRetry = false;
+	}
+	if (mShouldRetry)
+	{
+		LL_INFOS() << "Retry count " << mRetryCount << " should retry after " << wait_time << LL_ENDL;
+		mRetryTimer.reset();
+		mRetryTimer.setTimerExpirySec(wait_time);
+	}
+	mRetryCount++;
+}
+	
+
+bool LLAdaptiveRetryPolicy::shouldRetry(F32& seconds_to_wait) const
+{
+	if (mRetryCount == 0)
+	{
+		// Called shouldRetry before any failure.
+		seconds_to_wait = F32_MAX;
+		return false;
+	}
+	seconds_to_wait = mShouldRetry ? (F32) mRetryTimer.getRemainingTimeF32() : F32_MAX;
+	return mShouldRetry;
+}