From c4050134cc04b79fc24100eda98ea7c71d9b28c0 Mon Sep 17 00:00:00 2001
From: Jack Christensen <jack@jackchristensen.com>
Date: Sat, 12 Jan 2019 12:19:12 -0600
Subject: [PATCH] Begin delegation of Prepare to pgconn

---
 conn.go | 73 +++++++++++++++++----------------------------------------
 1 file changed, 21 insertions(+), 52 deletions(-)

diff --git a/conn.go b/conn.go
index 8db567c2..c19dfef8 100644
--- a/conn.go
+++ b/conn.go
@@ -538,64 +538,33 @@ func (c *Conn) prepareEx(name, sql string, opts *PrepareExOptions) (ps *Prepared
 		return nil, errors.Errorf("Number of PrepareExOptions ParameterOIDs must be between 0 and 65535, received %d", len(opts.ParameterOIDs))
 	}
 
-	buf := appendParse(c.wbuf, name, sql, opts.ParameterOIDs)
-	buf = appendDescribe(buf, 'S', name)
-	buf = appendSync(buf)
+	var paramOIDs []uint32
+	for _, oid := range opts.ParameterOIDs {
+		paramOIDs = append(paramOIDs, uint32(oid))
+	}
 
-	n, err := c.pgConn.Conn().Write(buf)
+	psd, err := c.pgConn.Prepare(context.TODO(), name, sql, paramOIDs)
 	if err != nil {
-		if fatalWriteErr(n, err) {
-			c.die(err)
-		}
 		return nil, err
 	}
-	c.pendingReadyForQueryCount++
 
-	ps = &PreparedStatement{Name: name, SQL: sql}
-
-	var softErr error
-
-	for {
-		msg, err := c.rxMsg()
-		if err != nil {
-			return nil, err
-		}
-
-		switch msg := msg.(type) {
-		case *pgproto3.ParameterDescription:
-			ps.ParameterOIDs = c.rxParameterDescription(msg)
-
-			if len(ps.ParameterOIDs) > 65535 && softErr == nil {
-				softErr = errors.Errorf("PostgreSQL supports maximum of 65535 parameters, received %d", len(ps.ParameterOIDs))
-			}
-		case *pgproto3.RowDescription:
-			ps.FieldDescriptions = c.rxRowDescription(msg)
-			for i := range ps.FieldDescriptions {
-				if dt, ok := c.ConnInfo.DataTypeForOID(ps.FieldDescriptions[i].DataType); ok {
-					ps.FieldDescriptions[i].DataTypeName = dt.Name
-					if _, ok := dt.Value.(pgtype.BinaryDecoder); ok {
-						ps.FieldDescriptions[i].FormatCode = BinaryFormatCode
-					} else {
-						ps.FieldDescriptions[i].FormatCode = TextFormatCode
-					}
-				} else {
-					return nil, errors.Errorf("unknown oid: %d", ps.FieldDescriptions[i].DataType)
-				}
-			}
-		case *pgproto3.ReadyForQuery:
-			c.rxReadyForQuery(msg)
-
-			if softErr == nil {
-				c.preparedStatements[name] = ps
-			}
-
-			return ps, softErr
-		default:
-			if e := c.processContextFreeMsg(msg); e != nil && softErr == nil {
-				softErr = e
-			}
-		}
+	ps = &PreparedStatement{
+		Name:              psd.Name,
+		SQL:               psd.SQL,
+		ParameterOIDs:     make([]pgtype.OID, len(psd.ParamOIDs)),
+		FieldDescriptions: make([]FieldDescription, len(psd.Fields)),
 	}
+
+	for i := range ps.ParameterOIDs {
+		ps.ParameterOIDs[i] = pgtype.OID(psd.ParamOIDs[i])
+	}
+	for i := range ps.FieldDescriptions {
+		c.pgproto3FieldDescriptionToPgxFieldDescription(&psd.Fields[i], &ps.FieldDescriptions[i])
+	}
+
+	c.preparedStatements[name] = ps
+
+	return ps, nil
 }
 
 // Deallocate released a prepared statement