feat: Include and exclude databases

- Add filters to include and exclude strings
- Use filters to include and exclude sessions (user and databases supported)
- Add tests to filters and terminator

Signed-off-by: Julien Riou <julien@riou.xyz>

base/filter.go

@@ -0,0 +1,122 @@
+package base
+
+import (
+	"fmt"
+	"reflect"
+	"regexp"
+)
+
+// Filter interface to tell if a string should be included or not
+type Filter interface {
+	Include(string) bool
+	String() string
+}
+
+// IncludeFilter to include a string when it's included in a list of strings
+type IncludeFilter struct {
+	patterns []string
+}
+
+// NewIncludeFilter to create an IncludeFilter
+func NewIncludeFilter(patterns []string) IncludeFilter {
+	return IncludeFilter{
+		patterns: patterns,
+	}
+}
+
+// Include returns true when a string is included in a list of patterns
+// Implements the Filter interface
+func (f IncludeFilter) Include(s string) bool {
+	// No or empty patterns must include
+	if f.patterns == nil || reflect.DeepEqual(f.patterns, []string{""}) {
+		return true
+	}
+	return InSlice(s, f.patterns)
+}
+
+// String to pretty print an IncludeFilter
+// Implements the Filter interface
+func (f IncludeFilter) String() string {
+	return fmt.Sprintf("<IncludeFilter(%s)>", f.patterns)
+}
+
+// IncludeFilterRegex to include a string when it matches a regex
+type IncludeFilterRegex struct {
+	regex *regexp.Regexp
+}
+
+// NewIncludeFilterRegex to create an IncludeFilterRegex
+func NewIncludeFilterRegex(regex *regexp.Regexp) IncludeFilterRegex {
+	return IncludeFilterRegex{
+		regex: regex,
+	}
+}
+
+// Include returns true when the string matches the regex
+// Implements the Filter interface
+func (f IncludeFilterRegex) Include(s string) bool {
+	if f.regex == nil || f.regex.MatchString(s) {
+		return true
+	}
+	return false
+}
+
+// String to pretty print an IncludeFilterRegex
+// Implements the Filter interface
+func (f IncludeFilterRegex) String() string {
+	return fmt.Sprintf("<IncludeFilterRegex(%s)>", f.regex.String())
+}
+
+// ExcludeFilter to include a string when it's not included in a list of strings
+type ExcludeFilter struct {
+	patterns []string
+}
+
+// NewExcludeFilter to create an ExcludeFilter
+func NewExcludeFilter(patterns []string) ExcludeFilter {
+	return ExcludeFilter{
+		patterns: patterns,
+	}
+}
+
+// Include returns true when the string is not included in the patterns
+// Implements the Filter interface
+func (f ExcludeFilter) Include(s string) bool {
+	return !InSlice(s, f.patterns)
+}
+
+// String to pretty print an ExcludeFilter
+// Implements the Filter interface
+func (f ExcludeFilter) String() string {
+	return fmt.Sprintf("<ExcludeFilter(%s)>", f.patterns)
+}
+
+// ExcludeFilterRegex to include a string when it doesnn't match a regex
+type ExcludeFilterRegex struct {
+	regex *regexp.Regexp
+}
+
+// NewExcludeFilterRegex to create an ExcludeFilterRegex
+func NewExcludeFilterRegex(regex *regexp.Regexp) ExcludeFilterRegex {
+	return ExcludeFilterRegex{
+		regex: regex,
+	}
+}
+
+// Include returns true when the string doesn't match the regex
+// Implements the Filter interface
+func (f ExcludeFilterRegex) Include(s string) bool {
+	if f.regex == nil || f.regex.MatchString("") {
+		return true
+	}
+	if f.regex.MatchString(s) {
+		return false
+	}
+	return true
+}
+
+// String to pretty print an ExcludeFilterRegex
+// Implements the Filter interface
+func (f ExcludeFilterRegex) String() string {
+	return fmt.Sprintf("<ExcludeFilterRegex(%s)>", f.regex.String())
+}