factored out http parser from asio into separate files (#444)

factored out http request parsing from httpasio into separate files to enable code to be reused for different transports

1 files changed, 113 insertions, 0 deletions

diff --git a/src/zenhttp/httpparser.h b/src/zenhttp/httpparser.h
new file mode 100644
index 000000000..cce51fcca
--- /dev/null
+++ b/src/zenhttp/httpparser.h
@@ -0,0 +1,113 @@
+// Copyright Epic Games, Inc. All Rights Reserved.
+
+#pragma once
+
+#include <zencore/uid.h>
+#include <zenhttp/httpcommon.h>
+
+ZEN_THIRD_PARTY_INCLUDES_START
+#include <http_parser.h>
+ZEN_THIRD_PARTY_INCLUDES_END
+
+namespace zen {
+
+class HttpConnectionBase
+{
+public:
+	virtual ~HttpConnectionBase()	   = default;
+	virtual void HandleNewRequest()	   = 0;
+	virtual void TerminateConnection() = 0;
+	virtual void HandleRequest()	   = 0;
+};
+
+struct HttpRequestParser
+{
+	explicit HttpRequestParser(HttpConnectionBase& Connection) : m_Connection(Connection) {}
+
+	void   Initialize();
+	size_t ConsumeData(const char* InputData, size_t DataSize);
+	void   ResetState();
+
+	HttpVerb		 RequestVerb() const { return m_RequestVerb; }
+	bool			 IsKeepAlive() const { return m_KeepAlive; }
+	std::string_view Url() const { return m_NormalizedUrl.empty() ? std::string_view(m_Url, m_UrlLength) : m_NormalizedUrl; }
+	std::string_view QueryString() const { return std::string_view(m_QueryString, m_QueryLength); }
+	IoBuffer		 Body() { return m_BodyBuffer; }
+
+	inline HttpContentType ContentType()
+	{
+		if (m_ContentTypeHeaderIndex < 0)
+		{
+			return HttpContentType::kUnknownContentType;
+		}
+
+		return ParseContentType(m_Headers[m_ContentTypeHeaderIndex].Value);
+	}
+
+	inline HttpContentType AcceptType()
+	{
+		if (m_AcceptHeaderIndex < 0)
+		{
+			return HttpContentType::kUnknownContentType;
+		}
+
+		return ParseContentType(m_Headers[m_AcceptHeaderIndex].Value);
+	}
+
+	Oid SessionId() const { return m_SessionId; }
+	int RequestId() const { return m_RequestId; }
+
+	std::string_view RangeHeader() const { return m_RangeHeaderIndex != -1 ? m_Headers[m_RangeHeaderIndex].Value : std::string_view(); }
+
+private:
+	struct HeaderEntry
+	{
+		HeaderEntry() = default;
+
+		HeaderEntry(std::string_view InName, std::string_view InValue) : Name(InName), Value(InValue) {}
+
+		std::string_view Name;
+		std::string_view Value;
+	};
+
+	HttpConnectionBase&		 m_Connection;
+	char*					 m_HeaderCursor				= m_HeaderBuffer;
+	char*					 m_Url						= nullptr;
+	size_t					 m_UrlLength				= 0;
+	char*					 m_QueryString				= nullptr;
+	size_t					 m_QueryLength				= 0;
+	char*					 m_CurrentHeaderName		= nullptr;	// Used while parsing headers
+	size_t					 m_CurrentHeaderNameLength	= 0;
+	char*					 m_CurrentHeaderValue		= nullptr;	// Used while parsing headers
+	size_t					 m_CurrentHeaderValueLength = 0;
+	std::vector<HeaderEntry> m_Headers;
+	int8_t					 m_ContentLengthHeaderIndex;
+	int8_t					 m_AcceptHeaderIndex;
+	int8_t					 m_ContentTypeHeaderIndex;
+	int8_t					 m_RangeHeaderIndex;
+	HttpVerb				 m_RequestVerb;
+	bool					 m_KeepAlive		 = false;
+	bool					 m_Expect100Continue = false;
+	int						 m_RequestId		 = -1;
+	Oid						 m_SessionId{};
+	IoBuffer				 m_BodyBuffer;
+	uint64_t				 m_BodyPosition = 0;
+	http_parser				 m_Parser;
+	char					 m_HeaderBuffer[1024];
+	std::string				 m_NormalizedUrl;
+
+	void AppendCurrentHeader();
+
+	int OnMessageBegin();
+	int OnUrl(const char* Data, size_t Bytes);
+	int OnHeader(const char* Data, size_t Bytes);
+	int OnHeaderValue(const char* Data, size_t Bytes);
+	int OnHeadersComplete();
+	int OnBody(const char* Data, size_t Bytes);
+	int OnMessageComplete();
+
+	static HttpRequestParser*	GetThis(http_parser* Parser) { return reinterpret_cast<HttpRequestParser*>(Parser->data); }
+	static http_parser_settings s_ParserSettings;
+};
+
+}  // namespace zen