1 files changed, 181 insertions, 0 deletions
diff --git a/src/zenutil/cloud/s3response.cpp b/src/zenutil/cloud/s3response.cpp
new file mode 100644
index 000000000..a9e7f0208
--- /dev/null
+++ b/src/zenutil/cloud/s3response.cpp
@@ -0,0 +1,181 @@
+// Copyright Epic Games, Inc. All Rights Reserved.
+
+#include <zenutil/cloud/s3response.h>
+
+#include <zencore/fmtutils.h>
+#include <zencore/logging.h>
+
+namespace zen {
+
+std::string_view
+S3ExtractXmlValue(std::string_view Xml, std::string_view Tag)
+{
+	std::string OpenTag	 = fmt::format("<{}>", Tag);
+	std::string CloseTag = fmt::format("</{}>", Tag);
+
+	size_t Start = Xml.find(OpenTag);
+	if (Start == std::string_view::npos)
+	{
+		return {};
+	}
+	Start += OpenTag.size();
+
+	size_t End = Xml.find(CloseTag, Start);
+	if (End == std::string_view::npos)
+	{
+		return {};
+	}
+
+	return Xml.substr(Start, End - Start);
+}
+
+void
+S3DecodeXmlEntities(std::string_view Input, StringBuilderBase& Out)
+{
+	if (Input.find('&') == std::string_view::npos)
+	{
+		Out.Append(Input);
+		return;
+	}
+
+	for (size_t i = 0; i < Input.size(); ++i)
+	{
+		if (Input[i] == '&')
+		{
+			std::string_view Remaining = Input.substr(i);
+			if (Remaining.starts_with("&amp;"))
+			{
+				Out.Append('&');
+				i += 4;
+			}
+			else if (Remaining.starts_with("&lt;"))
+			{
+				Out.Append('<');
+				i += 3;
+			}
+			else if (Remaining.starts_with("&gt;"))
+			{
+				Out.Append('>');
+				i += 3;
+			}
+			else if (Remaining.starts_with("&quot;"))
+			{
+				Out.Append('"');
+				i += 5;
+			}
+			else if (Remaining.starts_with("&apos;"))
+			{
+				Out.Append('\'');
+				i += 5;
+			}
+			else
+			{
+				Out.Append(Input[i]);
+			}
+		}
+		else
+		{
+			Out.Append(Input[i]);
+		}
+	}
+}
+
+std::string
+S3DecodeXmlEntities(std::string_view Input)
+{
+	if (Input.find('&') == std::string_view::npos)
+	{
+		return std::string(Input);
+	}
+	ExtendableStringBuilder<256> Sb;
+	S3DecodeXmlEntities(Input, Sb);
+	return Sb.ToString();
+}
+
+std::string
+S3BuildRequestPath(std::string_view Path, std::string_view CanonicalQS)
+{
+	if (CanonicalQS.empty())
+	{
+		return std::string(Path);
+	}
+	return fmt::format("{}?{}", Path, CanonicalQS);
+}
+
+const std::string*
+S3FindResponseHeader(const HttpClient::KeyValueMap& Headers, std::string_view Name)
+{
+	for (const auto& [K, V] : *Headers)
+	{
+		if (StrCaseCompare(K, Name) == 0)
+		{
+			return &V;
+		}
+	}
+	return nullptr;
+}
+
+bool
+S3ExtractError(std::string_view Body, std::string_view& OutCode, std::string_view& OutMessage)
+{
+	if (Body.find("<Error>") == std::string_view::npos)
+	{
+		return false;
+	}
+	OutCode	   = S3ExtractXmlValue(Body, "Code");
+	OutMessage = S3ExtractXmlValue(Body, "Message");
+	// Treat malformed bodies (Error tag present but no parseable Code/Message)
+	// as a parse miss; callers format "<prefix>: <Code> - <Message>" and an
+	// empty render is indistinguishable from "no error". S3IsThrottled with
+	// empty ErrorCode + S3ErrorMessage's Response.ErrorMessage fallback path
+	// covers status-only triage.
+	return !OutCode.empty() || !OutMessage.empty();
+}
+
+bool
+S3IsThrottled(const HttpClient::Response& Response, std::string_view ErrorCode)
+{
+	const int Status = static_cast<int>(Response.StatusCode);
+	if (Status == 503 || Status == 429)
+	{
+		return true;
+	}
+	if (ErrorCode == "SlowDown" || ErrorCode == "ServiceUnavailable" || ErrorCode == "ThrottlingException" ||
+		ErrorCode == "RequestLimitExceeded" || ErrorCode == "TooManyRequests")
+	{
+		return true;
+	}
+	return false;
+}
+
+std::string
+S3ErrorMessage(std::string_view Prefix, const HttpClient::Response& Response)
+{
+	if (!Response.Error.has_value() && Response.ResponsePayload)
+	{
+		std::string_view Body(reinterpret_cast<const char*>(Response.ResponsePayload.GetData()), Response.ResponsePayload.GetSize());
+		std::string_view Code;
+		std::string_view Message;
+		if (S3ExtractError(Body, Code, Message))
+		{
+			ExtendableStringBuilder<256> Decoded;
+			S3DecodeXmlEntities(Message, Decoded);
+			if (S3IsThrottled(Response, Code))
+			{
+				ZEN_WARN("S3 THROTTLED [{}] status={} code='{}' message='{}'",
+						 Prefix,
+						 static_cast<int>(Response.StatusCode),
+						 Code,
+						 Decoded.ToView());
+			}
+			return fmt::format("{}: HTTP status ({}) {} - {}", Prefix, static_cast<int>(Response.StatusCode), Code, Decoded.ToView());
+		}
+	}
+	if (S3IsThrottled(Response, {}))
+	{
+		ZEN_WARN("S3 THROTTLED [{}] status={} (no XML body)", Prefix, static_cast<int>(Response.StatusCode));
+	}
+	return Response.ErrorMessage(Prefix);
+}
+
+}  // namespace zen