Expose PQSendQueryParams and handle bytea data type

lib/db/postgres/connection.rb

@@ -101,6 +101,12 @@ def send_query(statement)
 				@native.send_query(statement)
 			end
 
+			def send_query_params(statement, *params)
+				@native.discard_results
+
+				@native.send_query_params(statement, *params)
+			end
+
 			def next_result
 				@native.next_result
 			end

lib/db/postgres/native/connection.rb

@@ -186,6 +186,29 @@ def send_query(statement)
 					flush
 				end
 
+				def send_query_params(statement, *params)
+					params = params.map(&:to_s)
+					size = params.size
+					is_binary = params.map { |param| param.include?("\x00".b) }
+
+					# type 17 => bytea (https://github.com/postgres/postgres/blob/master/src/include/catalog/pg_type.dat)
+					paramTypes = FFI::MemoryPointer.new(:int, params.size)
+					paramTypes.write_array_of_type(FFI::Type::INT, :put_int, is_binary.map { |binary| binary ? 17 : 0 })
+
+					paramValues = FFI::MemoryPointer.new(:pointer, params.size)
+					paramValues.write_array_of_pointer(params.map { |param| FFI::MemoryPointer.from_string(param) })
+
+					paramLengths = FFI::MemoryPointer.new(:int, params.size)
+					paramLengths.write_array_of_type(FFI::Type::INT, :put_int, params.zip(is_binary).map { |param, binary| binary ? param.bytesize : 0 })
+
+					paramFormats = FFI::MemoryPointer.new(:int, params.size)
+					paramFormats.write_array_of_type(FFI::Type::INT, :put_int, is_binary.map { |binary| binary ? 1 : 0 })
+
+					check! Native.send_query_params(self, statement, size, paramTypes, paramValues, paramLengths, paramFormats, 0)
+
+					flush
+				end
+
 				def next_result(types: @types)
 					if result = self.get_result
 						status = Native.result_status(result)

lib/db/postgres/native/field.rb

@@ -40,6 +40,8 @@ module Native
 				# These are hard coded OIDs.
 				16 => Types::Boolean.new,
 
+				17 => Types::ByteA.new,
+
 				20 => Types::Integer.new("int8"),
 				21 => Types::Integer.new("int2"),
 				23 => Types::Integer.new("int4"),

lib/db/postgres/native/types.rb

@@ -44,6 +44,16 @@ def parse(string)
 					end
 				end
 
+				class ByteA
+					def name
+						"BYTEA"
+					end
+
+					def parse(string)
+						[string[2..]].pack('H*') if string
+					end
+				end
+
 				class Decimal
 					def name
 						"DECIMAL"

test/db/postgres/connection.rb

@@ -26,6 +26,16 @@
 	ensure
 		connection.close
 	end
+
+	it "should execute query with arguments" do
+		connection.send_query_params("SELECT $1::BIGINT AS LIFE, $2 AS ANSWER", 42, "Life, the universe and everything")
+
+		result = connection.next_result
+
+		expect(result.to_a).to be == [[42, "Life, the universe and everything"]]
+	ensure
+		connection.close
+	end
 
 	it "should execute multiple queries" do
 		connection.send_query("SELECT 42 AS LIFE; SELECT 24 AS LIFE")
@@ -50,6 +60,28 @@
 		connection.close
 	end
 
+	it "can handle bytea output" do
+		connection.send_query("SELECT '\\x414243003839'::BYTEA")
+
+		result = connection.next_result
+		cell = result.to_a.first.first
+		expect(cell).to be == "ABC\x0089".b
+		expect(cell.encoding).to be == Encoding::ASCII_8BIT
+	ensure
+		connection.close
+	end
+
+	it "can handle bytea argument" do
+		connection.send_query_params("SELECT $1::BYTEA", "ABC\x0089".b)
+
+		result = connection.next_result
+		cell = result.to_a.first.first
+		expect(cell).to be == "ABC\x0089".b
+		expect(cell.encoding).to be == Encoding::ASCII_8BIT
+	ensure
+		connection.close
+	end
+
 	with '#append_string' do
 		it "should escape string" do
 			expect(connection.append_string("Hello 'World'")).to be == "'Hello ''World'''"