From f10de103715ef48db72220a7bb50ae69eaa83e4a Mon Sep 17 00:00:00 2001
From: Paul Reeves <preeves@ibphoenix.com>
Date: Tue, 24 Jan 2023 19:23:36 +0100
Subject: [PATCH] Add basic implementation of Blob_Save

---
 src/MyFirstUDRKit.cpp | 82 +++++++++++++++++++++++++++++--------------
 1 file changed, 55 insertions(+), 27 deletions(-)

diff --git a/src/MyFirstUDRKit.cpp b/src/MyFirstUDRKit.cpp
index 8a59269..236707b 100644
--- a/src/MyFirstUDRKit.cpp
+++ b/src/MyFirstUDRKit.cpp
@@ -29,10 +29,14 @@
 
 #include <ibase.h>
 #include <firebird/UdrCppEngine.h>
+#include "MyFirstUDRKit.h"
 
 #include <cassert>
 #include <cstdio>
 #include <cstdlib>
+#include <iostream>
+#include <fstream>
+#include <vector>
 
 #ifdef HAVE_MATH_H
 #include <math.h>
@@ -63,6 +67,7 @@
 
 #include <limits>
 
+using namespace std;
 using namespace Firebird;
 
 
@@ -107,6 +112,7 @@ FB_UDR_EXECUTE_FUNCTION
 		}
 		else
 		{
+// This is old style - surely we can do better?
 			out->result = std::numeric_limits<double>::infinity();
 			ISC_STATUS_ARRAY StatusVector = {isc_arg_gds, isc_arith_except,
 				isc_arg_gds, isc_exception_integer_divide_by_zero, isc_arg_end};
@@ -160,56 +166,78 @@ FB_UDR_BEGIN_FUNCTION(MFK_flagged)
 FB_UDR_END_FUNCTION
 
 
+
+
 /*** DDL
  create function Blob_Save (
 	afilename varchar(8191),
-	ablobcallback BLOB
+	ablob BLOB
 	) returns bigint
 	external name 'my_first_udr_kit!MFK_Blob_Save!Load file and save to Blob'
 	engine udr;
 ***/
+
+static const size_t MaxSegmentSize = 65535;
+
 FB_UDR_BEGIN_FUNCTION(MFK_Blob_Save)
 
 FB_UDR_MESSAGE(InMessage,
 							 (FB_CHAR(8191), afilename)
-							 (FB_BLOB, ablobcallback)
 );
 
 FB_UDR_MESSAGE(OutMessage,
+							 (FB_BLOB, ablob)
 							 (FB_BIGINT, result)
 );
 
+
+AutoRelease<IAttachment> att;
+AutoRelease<ITransaction> tra;
+
 FB_UDR_EXECUTE_FUNCTION
 {
 	// Test Input
-	if ((in->afilenameNull != 0) || in->ablobcallbackNull != 0 /* || in->ablobcallback.blob_handle == NULL */ ) {
+	if (in->afilenameNull != 0)  {
 		out->resultNull = FB_TRUE;
 		out->result = 0;
 	}
-	// open for write & as a binary...
-// 	FILE* file_ = fopen(s, "wb");
-// 	if (file_ == NULL) {
-// 		ISC_INT64* res = MALLOC(sizeof(ISC_INT64));
-// 		*res = -2;
-// 		return res;
-// 	}
-// 	// allocate buffer size to equal with max segment size
-// 	ISC_UCHAR* buffer = malloc(b->blob_max_segment);
-// 	if (!buffer) {
-// 		ISC_INT64* res = MALLOC(sizeof(ISC_INT64));
-// 		*res = -1;
-// 		return res;
-// 	}
-// 	/* see BLOBCALLBACK in ibase.h */
-// 	ISC_INT64* res = MALLOC(sizeof(ISC_INT64));
-// 	*res = 0;
-// 	ISC_USHORT len;
-// 	while (b->blob_get_segment(b->blob_handle, buffer, b->blob_max_segment, &len)) {
-// 		*res += fwrite(buffer, 1, len, file_); // write buffer into given file..	(size as per 1 Byte for an element)
-// 	}
-// 	free(buffer);
-// 	fclose(file_);
-// 	return res;
+
+	ifstream File ( in->afilename.str , ios_base::in | ios_base::binary );
+	if (! File.is_open()) {
+		out->result = -2;
+		return;
+	}
+
+	AutoRelease<IBlob> Blob(att->createBlob(status, tra, &out->ablob, 0, nullptr));
+	if (Blob == nullptr) {
+		out->result = -1;
+		return;
+	}
+
+	vector<char> Buffer (MaxSegmentSize, 0);
+	streamsize DataSize;
+
+	while  ( !File.good() ) {
+		File.read( Buffer.data(), Buffer.size() );
+		DataSize = File.gcount();
+		Blob->putSegment( status, DataSize, Buffer.data() );
+		out->result += DataSize;
+		// Perhaps test for badbit here?
+	}
+	if (File.bad()) { // Something went wrong
+		// What to do?
+		out->resultNull = FB_TRUE;
+		// What do we do with the partially written blob? Is cancel enough?
+		Blob->cancel( status );
+		// Should we reset result to 0?
+
+	}
+
+	Blob->close( status );
+	Blob->release();
+
+	Buffer.clear();
+	File.close();
 
 }