Initial implementation of CbPackage HTTP response writing

1 files changed, 68 insertions, 39 deletions

diff --git a/zencore/httpserver.cpp b/zencore/httpserver.cpp
index eaa8bdfcd..587eab279 100644
--- a/zencore/httpserver.cpp
+++ b/zencore/httpserver.cpp
@@ -273,49 +273,78 @@ HttpServerRequest::~HttpServerRequest()
 void
 HttpServerRequest::WriteResponse(HttpResponse HttpResponseCode, CbPackage Data)
 {
-	// TODO: implement efficient version of this which can send package attachment
-	//		 payloads directly from disk
-	ZEN_UNUSED(HttpResponseCode, Data);
-	ZEN_NOT_IMPLEMENTED();
+	const std::span<const CbAttachment>& Attachments = Data.GetAttachments();
+
+	struct CbPackageHeader
+	{
+		uint32_t HeaderMagic;
+		uint32_t AttachmentCount;
+		uint32_t Reserved1;
+		uint32_t Reserved2;
+	};
+
+	static constinit uint32_t kMagic = 0xaa77aacc;
+
+	struct CbAttachmentEntry
+	{
+		uint64_t AttachmentSize;
+		uint32_t Reserved1;
+		IoHash	 AttachmentHash;
+	};
+
+	std::vector<IoBuffer> ResponseBuffers;
+	ResponseBuffers.reserve(3 + Attachments.size());  // TODO: may want to use an additional fudge factor here to avoid growing since each
+													  // attachment is likely to consist of several buffers
+
+	uint64_t TotalAttachmentsSize = 0;
+
+	// Fixed size header
+
+	CbPackageHeader Hdr{.HeaderMagic = kMagic, .AttachmentCount = gsl::narrow<uint32_t>(Attachments.size())};
+
+	ResponseBuffers.push_back(IoBufferBuilder::MakeCloneFromMemory(&Hdr, sizeof Hdr));
+
+	// Attachment metadata array
+
+	IoBuffer AttachmentMetadataBuffer = IoBuffer{sizeof(CbAttachmentEntry) * (Attachments.size() + /* root */ 1)};
+
+	CbAttachmentEntry* AttachmentInfo = reinterpret_cast<CbAttachmentEntry*>(AttachmentMetadataBuffer.MutableData());
+
+	ResponseBuffers.push_back(AttachmentMetadataBuffer);  // Attachment metadata
+
+	// Root object
+
+	IoBuffer RootIoBuffer = Data.GetObject().GetBuffer().AsIoBuffer();
+	ResponseBuffers.push_back(RootIoBuffer);  // Root object
+
+	*AttachmentInfo++ = {.AttachmentSize = RootIoBuffer.Size(), .AttachmentHash = Data.GetObjectHash()};
+
+	// Attachment payloads
+
+	for (const CbAttachment& Attachment : Attachments)
+	{
+		CompressedBuffer AttachmentBuffer = Attachment.AsCompressedBinary();
+		CompositeBuffer	 Compressed		  = AttachmentBuffer.GetCompressed();
+
+		*AttachmentInfo++ = {.AttachmentSize = AttachmentBuffer.GetCompressedSize(),
+							 .AttachmentHash = IoHash::FromBLAKE3(AttachmentBuffer.GetRawHash())};
+
+		for (const SharedBuffer& Segment : Compressed.GetSegments())
+		{
+			ResponseBuffers.push_back(Segment.AsIoBuffer());
+			TotalAttachmentsSize += Segment.GetSize();
+		}
+	}
+
+	return WriteResponse(HttpResponseCode, HttpContentType::kCbPackage, ResponseBuffers);
 }
 
 void
 HttpServerRequest::WriteResponse(HttpResponse HttpResponseCode, CbObject Data)
 {
-#if 0
-	struct Visitor : public ICbVisitor
-	{
-		virtual void SetName(std::string_view Name) override { OutText << '\'' << Name << "': "; }
-		virtual void BeginObject() override { OutText << "{ "; }
-		virtual void EndObject() override { OutText << "}"; }
-		virtual void BeginArray() override { OutText << "[ "; }
-		virtual void EndArray() override { OutText << " ]"; }
-
-		virtual void VisitNull() override { OutText << "null"; }
-		virtual void VisitBinary(SharedBuffer Value) override { ZEN_UNUSED(Value); }
-		virtual void VisitString(std::string_view Value) override { ZEN_UNUSED(Value); }
-		virtual void VisitInteger(int64_t Value) override { OutText << Value; }
-		virtual void VisitInteger(uint64_t Value) override { OutText << Value; }
-		virtual void VisitFloat(float Value) override { ZEN_UNUSED(Value); }
-		virtual void VisitDouble(double Value) override { ZEN_UNUSED(Value); }
-		virtual void VisitBool(bool Value) override { OutText << Value; }
-		virtual void VisitCbAttachment(const IoHash& Value) override { ZEN_UNUSED(Value); }
-		virtual void VisitBinaryAttachment(const IoHash& Value) override { ZEN_UNUSED(Value); }
-		virtual void VisitHash(const IoHash& Value) override { ZEN_UNUSED(Value); }
-		virtual void VisitUuid(const Guid& Value) override { ZEN_UNUSED(Value); }
-		virtual void VisitObjectId(const Oid& Value) override { ZEN_UNUSED(Value); }
-		virtual void VisitDateTime(DateTime Value) override { ZEN_UNUSED(Value); }
-		virtual void VisitTimeSpan(TimeSpan Value) override { ZEN_UNUSED(Value); }
-
-		ExtendableStringBuilder<256> OutText;
-	} _;
-	// Data.CreateRefIterator().VisitFields(_);
-	return WriteResponse(HttpResponseCode, HttpContentType::kJSON, _.OutText);
-#else
 	SharedBuffer			Buf = Data.GetBuffer();
-	std::array<IoBuffer, 1> buffers{IoBufferBuilder::MakeCloneFromMemory(Buf.GetData(), Buf.GetSize())};
-	return WriteResponse(HttpResponseCode, HttpContentType::kCbObject, buffers);
-#endif
+	std::array<IoBuffer, 1> Buffers{IoBufferBuilder::MakeCloneFromMemory(Buf.GetData(), Buf.GetSize())};
+	return WriteResponse(HttpResponseCode, HttpContentType::kCbObject, Buffers);
 }
 
 void
@@ -327,8 +356,8 @@ HttpServerRequest::WriteResponse(HttpResponse HttpResponseCode, HttpContentType
 void
 HttpServerRequest::WriteResponse(HttpResponse HttpResponseCode, HttpContentType ContentType, IoBuffer Blob)
 {
-	std::array<IoBuffer, 1> buffers{Blob};
-	return WriteResponse(HttpResponseCode, ContentType, buffers);
+	std::array<IoBuffer, 1> Buffers{Blob};
+	return WriteResponse(HttpResponseCode, ContentType, Buffers);
 }
 
 HttpServerRequest::QueryParams