HTTP range responses (RFC 7233) - httpobjectstore (#928)

- Improvement: HTTP range responses (RFC 7233) are now fully compliant across the object store and build store
  - 206 Partial Content responses now include a `Content-Range` header; previously absent for single-range requests, which broke `HttpClient::GetRanges()`
  - 416 Range Not Satisfiable responses now include `Content-Range: bytes */N` as required by RFC 7233
  - Out-of-bounds range requests return 416 Range Not Satisfiable (was 400 Bad Request)
  - Single-byte ranges (`bytes=N-N`) are now correctly accepted (were previously rejected)
  - Range byte positions widened from 32-bit to 64-bit; RFC 7233 imposes no size limit on byte range values
  - Build store binary GET requests with a Range header now return 206 Partial Content with `Content-Range` (previously returned 200 OK without it)

1 files changed, 26 insertions, 2 deletions

diff --git a/src/zenhttp/servers/httpasio.cpp b/src/zenhttp/servers/httpasio.cpp
index 6cda84875..cfba3c95f 100644
--- a/src/zenhttp/servers/httpasio.cpp
+++ b/src/zenhttp/servers/httpasio.cpp
@@ -625,6 +625,8 @@ public:
 
 	void SetAllowZeroCopyFileSend(bool Allow) { m_AllowZeroCopyFileSend = Allow; }
 	void SetKeepAlive(bool KeepAlive) { m_IsKeepAlive = KeepAlive; }
+	void SetContentTypeOverride(std::string Override) { m_ContentTypeOverride = std::move(Override); }
+	void SetContentRangeHeader(std::string V) { m_ContentRangeHeader = std::move(V); }
 
 	/**
 	 * Initialize the response for sending a payload made up of multiple blobs
@@ -768,10 +770,18 @@ public:
 	{
 		ZEN_MEMSCOPE(GetHttpasioTag());
 
+		std::string_view ContentTypeStr =
+			m_ContentTypeOverride.empty() ? MapContentTypeToString(m_ContentType) : std::string_view(m_ContentTypeOverride);
+
 		m_Headers << "HTTP/1.1 " << ResponseCode() << " " << ReasonStringForHttpResultCode(ResponseCode()) << "\r\n"
-				  << "Content-Type: " << MapContentTypeToString(m_ContentType) << "\r\n"
+				  << "Content-Type: " << ContentTypeStr << "\r\n"
 				  << "Content-Length: " << ContentLength() << "\r\n"sv;
 
+		if (!m_ContentRangeHeader.empty())
+		{
+			m_Headers << "Content-Range: " << m_ContentRangeHeader << "\r\n"sv;
+		}
+
 		if (!m_IsKeepAlive)
 		{
 			m_Headers << "Connection: close\r\n"sv;
@@ -898,7 +908,9 @@ private:
 	bool							 m_AllowZeroCopyFileSend = true;
 	State							 m_State				 = State::kUninitialized;
 	HttpContentType					 m_ContentType			 = HttpContentType::kBinary;
-	uint64_t						 m_ContentLength		 = 0;
+	std::string						 m_ContentTypeOverride;
+	std::string						 m_ContentRangeHeader;
+	uint64_t						 m_ContentLength = 0;
 	eastl::fixed_vector<IoBuffer, 8> m_DataBuffers;	 // This is here to keep the IoBuffer buffers/handles alive
 	ExtendableStringBuilder<160>	 m_Headers;
 
@@ -2131,6 +2143,10 @@ HttpAsioServerRequest::WriteResponse(HttpResponseCode ResponseCode)
 	m_Response.reset(new HttpResponse(HttpContentType::kBinary, m_RequestNumber));
 	m_Response->SetAllowZeroCopyFileSend(m_AllowZeroCopyFileSend);
 	m_Response->SetKeepAlive(m_Request.IsKeepAlive());
+	if (!m_ContentRangeHeader.empty())
+	{
+		m_Response->SetContentRangeHeader(std::move(m_ContentRangeHeader));
+	}
 	std::array<IoBuffer, 0> Empty;
 
 	m_Response->InitializeForPayload((uint16_t)ResponseCode, Empty);
@@ -2146,6 +2162,14 @@ HttpAsioServerRequest::WriteResponse(HttpResponseCode ResponseCode, HttpContentT
 	m_Response.reset(new HttpResponse(ContentType, m_RequestNumber));
 	m_Response->SetAllowZeroCopyFileSend(m_AllowZeroCopyFileSend);
 	m_Response->SetKeepAlive(m_Request.IsKeepAlive());
+	if (!m_ContentTypeOverride.empty())
+	{
+		m_Response->SetContentTypeOverride(std::move(m_ContentTypeOverride));
+	}
+	if (!m_ContentRangeHeader.empty())
+	{
+		m_Response->SetContentRangeHeader(std::move(m_ContentRangeHeader));
+	}
 	m_Response->InitializeForPayload((uint16_t)ResponseCode, Blobs);
 }