binpac: Adding an interface to manually control the buffering for generated

parsers.

This consists of two parts:

    1. The generated Flow classes expose their flow buffers via a new
       method flow_buffer().

    2. Flow buffers get two new methods:

        // Interface for delayed parsing. Sometimes BinPAC doesn't get the
        // buffering right and then one can use these to feed parts
        // individually and assemble them internally. After calling
        // FinishBuffer(), one can send the uppper-layer flow an FlowEOF()
        // to trigger parsing.
        void BufferData(const_byteptr data, const_byteptr end);
        void FinishBuffer();

tools/binpac/lib/binpac_buffer.cc

@@ -137,6 +137,19 @@ void FlowBuffer::NewFrame(int frame_length, bool chunked)
 	MarkOrCopyFrame();
 	}
 
+void FlowBuffer::BufferData(const_byteptr data, const_byteptr end)
+	{
+	mode_ = FRAME_MODE;
+	frame_length_ += (end - data);
+	MarkOrCopyFrame();
+	NewData(data, end);
+	}
+
+void FlowBuffer::FinishBuffer()
+	{
+	message_complete_ = true;
+	}
+
 void FlowBuffer::GrowFrame(int length)
 	{
 	BINPAC_ASSERT(frame_length_ >= 0);

tools/binpac/lib/binpac_buffer.h

@@ -8,7 +8,7 @@ namespace binpac {
 
 class FlowBuffer {
 public:
-	enum LineBreakStyle { 
+	enum LineBreakStyle {
 		CR_OR_LF, 	// CR or LF or CRLF
 		STRICT_CRLF, 	// CR followed by LF
 		CR_LF_NUL,	// CR or LF or CR-LF or CR-NUL
@@ -20,6 +20,14 @@ public:
 	void NewData(const_byteptr begin, const_byteptr end);
 	void NewGap(int length);
 
+	// Interface for delayed parsing. Sometimes BinPAC doesn't get the
+	// buffering right and then one can use these to feed parts
+	// individually and assemble them internally. After calling
+	// FinishBuffer(), one can send the uppper-layer flow an FlowEOF() to
+	// trigger parsing.
+	void BufferData(const_byteptr data, const_byteptr end);
+	void FinishBuffer();
+
 	// Discard unprocessed data
 	void DiscardData();
 

tools/binpac/src/pac_flow.cc

@@ -68,7 +68,7 @@ void FlowDecl::ProcessDataUnitElement(AnalyzerDataUnit *dataunit_elem)
 		{
 		dataunit_->data_type()->MarkIncrementalInput();
 
-		flow_buffer_var_field_ = new PrivVarField(
+		flow_buffer_var_field_ = new PubVarField(
 			flow_buffer_id->clone(),
 			FlowDecl::flow_buffer_type()->Clone());
 		type_->AddField(flow_buffer_var_field_);