replace dsn parser with simple parser, rather than regex

conn.go

@@ -17,7 +17,6 @@ import (
 	"os/user"
 	"path/filepath"
 	"reflect"
-	"regexp"
 	"strconv"
 	"strings"
 	"sync"
@@ -1062,7 +1061,7 @@ func ParseURI(uri string) (ConnConfig, error) {
 	return cp, nil
 }
 
-var dsnRegexp = regexp.MustCompile(`([a-zA-Z_]+)=((?:"[^"]+")|(?:[^ ]+))`)
+var asciiSpace = [256]uint8{'\t': 1, '\n': 1, '\v': 1, '\f': 1, '\r': 1, ' ': 1}
 
 // ParseDSN parses a database DSN (data source name) into a ConnConfig
 //
@@ -1078,35 +1077,79 @@ var dsnRegexp = regexp.MustCompile(`([a-zA-Z_]+)=((?:"[^"]+")|(?:[^ ]+))`)
 func ParseDSN(s string) (ConnConfig, error) {
 	var cp ConnConfig
 
-	m := dsnRegexp.FindAllStringSubmatch(s, -1)
-
 	tlsArgs := configTLSArgs{}
 
 	cp.RuntimeParams = make(map[string]string)
 
 	var hostval, portval string
-	for _, b := range m {
+	for len(s) > 0 {
-		switch b[1] {
+		var key, val string
+		eqIdx := strings.IndexRune(s, '=')
+		if eqIdx < 0 {
+			return cp, errors.New("invalid dsn")
+		}
+
+		key = strings.Trim(s[:eqIdx], " \t\n\r\v\f")
+		s = strings.TrimLeft(s[eqIdx+1:], " \t\n\r\v\f")
+		if s[0] != '\'' {
+			end := 0
+			for ; end < len(s); end++ {
+				if asciiSpace[s[end]] == 1 {
+					break
+				}
+				if s[end] == '\\' {
+					end++
+				}
+			}
+			val = strings.Replace(strings.Replace(s[:end], "\\\\", "\\", -1), "\\'", "'", -1)
+			if end == len(s) {
+				s = ""
+			} else {
+				s = s[end+1:]
+			}
+		} else { // quoted string
+			s = s[1:]
+			end := 0
+			for ; end < len(s); end++ {
+				if s[end] == '\'' {
+					break
+				}
+				if s[end] == '\\' {
+					end++
+				}
+			}
+			if end == len(s) {
+				return cp, errors.New("unterminated quoted string in connection info string")
+			}
+			val = strings.Replace(strings.Replace(s[:end], "\\\\", "\\", -1), "\\'", "'", -1)
+			if end == len(s) {
+				s = ""
+			} else {
+				s = s[end+1:]
+			}
+		}
+
+		switch key {
 		case "user":
-			cp.User = b[2]
+			cp.User = val
 		case "password":
-			cp.Password = b[2]
+			cp.Password = val
 		case "host":
-			hostval = b[2]
+			hostval = val
 		case "port":
-			portval = b[2]
+			portval = val
 		case "dbname":
-			cp.Database = b[2]
+			cp.Database = val
 		case "sslmode":
-			tlsArgs.sslMode = b[2]
+			tlsArgs.sslMode = val
 		case "sslrootcert":
-			tlsArgs.sslRootCert = b[2]
+			tlsArgs.sslRootCert = val
 		case "sslcert":
-			tlsArgs.sslCert = b[2]
+			tlsArgs.sslCert = val
 		case "sslkey":
-			tlsArgs.sslKey = b[2]
+			tlsArgs.sslKey = val
 		case "connect_timeout":
-			timeout, err := strconv.ParseInt(b[2], 10, 64)
+			timeout, err := strconv.ParseInt(val, 10, 64)
 			if err != nil {
 				return cp, err
 			}
@@ -1114,12 +1157,12 @@ func ParseDSN(s string) (ConnConfig, error) {
 			d.Timeout = time.Duration(timeout) * time.Second
 			cp.Dial = d.Dial
 		case "target_session_attrs":
-			cp.TargetSessionAttrs = TargetSessionType(b[2])
+			cp.TargetSessionAttrs = TargetSessionType(val)
 			if err := cp.TargetSessionAttrs.isValid(); err != nil {
 				return cp, err
 			}
 		default:
-			cp.RuntimeParams[b[1]] = b[2]
+			cp.RuntimeParams[key] = val
 		}
 	}
 

conn_test.go

@@ -717,6 +717,38 @@ func TestParseDSN(t *testing.T) {
 				RuntimeParams:     map[string]string{},
 			},
 		},
+		{
+			url: "user=jack\\'s password=secret host=localhost port=5432 dbname=mydb",
+			connParams: pgx.ConnConfig{
+				User:     "jack's",
+				Password: "secret",
+				Host:     "localhost",
+				Port:     5432,
+				Database: "mydb",
+				TLSConfig: &tls.Config{
+					InsecureSkipVerify: true,
+				},
+				UseFallbackTLS:    true,
+				FallbackTLSConfig: nil,
+				RuntimeParams:     map[string]string{},
+			},
+		},
+		{
+			url: "user=jack password=sooper\\\\secret host=localhost port=5432 dbname=mydb",
+			connParams: pgx.ConnConfig{
+				User:     "jack",
+				Password: "sooper\\secret",
+				Host:     "localhost",
+				Port:     5432,
+				Database: "mydb",
+				TLSConfig: &tls.Config{
+					InsecureSkipVerify: true,
+				},
+				UseFallbackTLS:    true,
+				FallbackTLSConfig: nil,
+				RuntimeParams:     map[string]string{},
+			},
+		},
 		{
 			url: "user=jack host=localhost port=5432 dbname=mydb",
 			connParams: pgx.ConnConfig{
@@ -822,6 +854,62 @@ func TestParseDSN(t *testing.T) {
 				TargetSessionAttrs: pgx.ReadWriteTargetSession,
 			},
 		},
+		{
+			url: "user='jack' host='localhost' dbname='mydb'",
+			connParams: pgx.ConnConfig{
+				User:     "jack",
+				Host:     "localhost",
+				Database: "mydb",
+				TLSConfig: &tls.Config{
+					InsecureSkipVerify: true,
+				},
+				UseFallbackTLS:    true,
+				FallbackTLSConfig: nil,
+				RuntimeParams:     map[string]string{},
+			},
+		},
+		{
+			url: "user='jack\\'s' host='localhost' dbname='mydb'",
+			connParams: pgx.ConnConfig{
+				User:     "jack's",
+				Host:     "localhost",
+				Database: "mydb",
+				TLSConfig: &tls.Config{
+					InsecureSkipVerify: true,
+				},
+				UseFallbackTLS:    true,
+				FallbackTLSConfig: nil,
+				RuntimeParams:     map[string]string{},
+			},
+		},
+		{
+			url: "user='jack' password='' host='localhost' dbname='mydb'",
+			connParams: pgx.ConnConfig{
+				User:     "jack",
+				Host:     "localhost",
+				Database: "mydb",
+				TLSConfig: &tls.Config{
+					InsecureSkipVerify: true,
+				},
+				UseFallbackTLS:    true,
+				FallbackTLSConfig: nil,
+				RuntimeParams:     map[string]string{},
+			},
+		},
+		{
+			url: "user = 'jack' password = '' host = 'localhost' dbname = 'mydb'",
+			connParams: pgx.ConnConfig{
+				User:     "jack",
+				Host:     "localhost",
+				Database: "mydb",
+				TLSConfig: &tls.Config{
+					InsecureSkipVerify: true,
+				},
+				UseFallbackTLS:    true,
+				FallbackTLSConfig: nil,
+				RuntimeParams:     map[string]string{},
+			},
+		},
 	}
 
 	for i, tt := range tests {