64 lines
2.4 KiB
C++
64 lines
2.4 KiB
C++
/**
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* Copyright Amazon.com, Inc. or its affiliates. All Rights Reserved.
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* SPDX-License-Identifier: Apache-2.0.
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*/
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#pragma once
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#include <aws/core/platform/Environment.h>
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#include <aws/core/http/HttpRequest.h>
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#include <iomanip>
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namespace smithy
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{
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namespace client
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{
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static const char SMITHY_AWS_LAMBDA_FUNCTION_NAME[] = "AWS_LAMBDA_FUNCTION_NAME";
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static const char SMITHY_X_AMZN_TRACE_ID[] = "_X_AMZN_TRACE_ID";
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class RecursionDetection
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{
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public:
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static void AppendRecursionDetectionHeader(const std::shared_ptr<Aws::Http::HttpRequest>& ioRequest)
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{
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if (!ioRequest || ioRequest->HasHeader(Aws::Http::X_AMZN_TRACE_ID_HEADER))
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{
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return;
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}
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const Aws::String& awsLambdaFunctionName = Aws::Environment::GetEnv(SMITHY_AWS_LAMBDA_FUNCTION_NAME);
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if (awsLambdaFunctionName.empty())
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{
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return;
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}
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Aws::String xAmznTraceIdVal = Aws::Environment::GetEnv(SMITHY_X_AMZN_TRACE_ID);
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if (xAmznTraceIdVal.empty())
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{
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return;
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}
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// Escape all non-printable ASCII characters by percent encoding
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Aws::OStringStream xAmznTraceIdValEncodedStr;
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for (const char ch : xAmznTraceIdVal)
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{
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if (ch >= 0x20 && ch <= 0x7e) // ascii chars [32-126] or [' ' to '~'] are not escaped
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{
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xAmznTraceIdValEncodedStr << ch;
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}
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else
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{
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// A percent-encoded octet is encoded as a character triplet
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xAmznTraceIdValEncodedStr << '%' // consisting of the percent character "%"
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<< std::hex << std::setfill('0') << std::setw(2) << std::uppercase
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<< (size_t)ch
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//followed by the two hexadecimal digits representing that octet's numeric value
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<< std::dec << std::setfill(' ') << std::setw(0) << std::nouppercase;
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}
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}
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xAmznTraceIdVal = xAmznTraceIdValEncodedStr.str();
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ioRequest->SetHeaderValue(Aws::Http::X_AMZN_TRACE_ID_HEADER, xAmznTraceIdVal);
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}
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};
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}
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}
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