Use unique_ptr for handling unescaped bytea column buffer

2 files changed, 16 insertions, 18 deletions

diff --git a/libpqpp/pq-column.cpp b/libpqpp/pq-column.cpp
index cd0d60c..f78863c 100644
--- a/libpqpp/pq-column.cpp
+++ b/libpqpp/pq-column.cpp
@@ -9,22 +9,13 @@
 #include <cstdlib>
 #include <cstring>
 #include <libpq-fe.h>
-#include <memory>
 #include <server/catalog/pg_type_d.h>
 
 PQ::Column::Column(const SelectBase * s, unsigned int i) :
-	DB::Column(PQfname(s->execRes, static_cast<int>(i)), i), sc(s), oid(PQftype(sc->execRes, static_cast<int>(colNo))),
-	buf(nullptr)
+	DB::Column(PQfname(s->execRes, static_cast<int>(i)), i), sc(s), oid(PQftype(sc->execRes, static_cast<int>(colNo)))
 {
 }
 
-PQ::Column::~Column()
-{
-	if (buf) {
-		PQfreemem(buf);
-	}
-}
-
 bool
 PQ::Column::isNull() const
 {
@@ -97,12 +88,10 @@ PQ::Column::apply(DB::HandleField & h) const
 			h.timestamp(boost::posix_time::time_from_string(value()));
 			break;
 		case BYTEAOID: {
-			if (buf) {
-				PQfreemem(buf);
-			}
-			size_t len;
-			buf = PQunescapeBytea(reinterpret_cast<const unsigned char *>(value()), &len);
-			h.blob(DB::Blob(buf, len));
+			size_t len = 0;
+			// NOLINTNEXTLINE(cppcoreguidelines-pro-type-reinterpret-cast)
+			buf = BufPtr {PQunescapeBytea(reinterpret_cast<const unsigned char *>(value()), &len)};
+			h.blob(DB::Blob(buf.get(), len));
 			break;
 		}
 	}
diff --git a/libpqpp/pq-column.h b/libpqpp/pq-column.h
index f86958e..d3400bf 100644
--- a/libpqpp/pq-column.h
+++ b/libpqpp/pq-column.h
@@ -11,7 +11,6 @@ namespace PQ {
 	class Column : public DB::Column {
 	public:
 		Column(const SelectBase *, unsigned int field);
-		~Column() override;
 
 		[[nodiscard]] bool isNull() const override;
 		void apply(DB::HandleField &) const override;
@@ -31,8 +30,18 @@ namespace PQ {
 
 		const SelectBase * sc;
 		const Oid oid;
+
 		// Buffer for PQunescapeBytea
-		mutable unsigned char * buf;
+		struct pq_deleter {
+			void
+			operator()(unsigned char * p)
+			{
+				PQfreemem(p);
+			}
+		};
+
+		using BufPtr = std::unique_ptr<unsigned char, pq_deleter>;
+		mutable BufPtr buf;
 	};
 }