ResourceServer: Resource store sql backend (#90170)

pkg/storage/unified/sql/db/dbimpl/util.go

@@ -0,0 +1,111 @@
+package dbimpl
+
+import (
+	"cmp"
+	"errors"
+	"fmt"
+	"net"
+	"sort"
+	"strings"
+	"unicode/utf8"
+
+	"github.com/grafana/grafana/pkg/setting"
+)
+
+var (
+	ErrInvalidUTF8Sequence = errors.New("invalid UTF-8 sequence")
+)
+
+type sectionGetter struct {
+	*setting.DynamicSection
+	err error
+}
+
+func (g *sectionGetter) Err() error {
+	return g.err
+}
+
+func (g *sectionGetter) String(key string) string {
+	v := g.DynamicSection.Key(key).MustString("")
+	if !utf8.ValidString(v) {
+		g.err = fmt.Errorf("value for key %q: %w", key, ErrInvalidUTF8Sequence)
+
+		return ""
+	}
+
+	return v
+}
+
+// MakeDSN creates a DSN from the given key/value pair. It validates the strings
+// form valid UTF-8 sequences and escapes values if needed.
+func MakeDSN(m map[string]string) (string, error) {
+	b := new(strings.Builder)
+
+	ks := keys(m)
+	sort.Strings(ks) // provide deterministic behaviour
+	for _, k := range ks {
+		v := m[k]
+		if !utf8.ValidString(v) {
+			return "", fmt.Errorf("value for DSN key %q: %w", k,
+				ErrInvalidUTF8Sequence)
+		}
+		if v == "" {
+			continue
+		}
+
+		if b.Len() > 0 {
+			_ = b.WriteByte(' ')
+		}
+		_, _ = b.WriteString(k)
+		_ = b.WriteByte('=')
+		writeDSNValue(b, v)
+	}
+
+	return b.String(), nil
+}
+
+func keys(m map[string]string) []string {
+	ret := make([]string, 0, len(m))
+	for k := range m {
+		ret = append(ret, k)
+	}
+	return ret
+}
+
+func writeDSNValue(b *strings.Builder, v string) {
+	numq := strings.Count(v, `'`)
+	numb := strings.Count(v, `\`)
+	if numq+numb == 0 && v != "" {
+		b.WriteString(v)
+
+		return
+	}
+	b.Grow(2 + numq + numb + len(v))
+
+	_ = b.WriteByte('\'')
+	for _, r := range v {
+		if r == '\\' || r == '\'' {
+			_ = b.WriteByte('\\')
+		}
+		_, _ = b.WriteRune(r)
+	}
+	_ = b.WriteByte('\'')
+}
+
+// splitHostPortDefault is similar to net.SplitHostPort, but will also accept a
+// specification with no port and apply the default port instead. It also
+// applies the given defaults if the results are empty strings.
+func splitHostPortDefault(hostport, defaultHost, defaultPort string) (string, string, error) {
+	host, port, err := net.SplitHostPort(hostport)
+	if err != nil {
+		// try appending the port
+		host, port, err = net.SplitHostPort(hostport + ":" + defaultPort)
+		if err != nil {
+			return "", "", fmt.Errorf("invalid hostport: %q", hostport)
+		}
+	}
+	host = cmp.Or(host, defaultHost)
+	port = cmp.Or(port, defaultPort)
+
+	return host, port, nil
+}