fs: re-implement DumpMode with Bits

This almost 100% backwards compatible. The only difference being that
in the rc options/get output DumpMode will be output as strings
instead of integers. This is a lot more convenient for the user. They
still accept integer inputs though so the fallout from this should be
minimal.

fs/dump.go

@@ -1,12 +1,7 @@
 package fs
 
-import (
-	"fmt"
-	"strings"
-)
-
 // DumpFlags describes the Dump options in force
-type DumpFlags int
+type DumpFlags = Bits[dumpChoices]
 
 // DumpFlags definitions
 const (
@@ -20,80 +15,24 @@ const (
 	DumpOpenFiles
 )
 
-var dumpFlags = []struct {
-	flag DumpFlags
-	name string
-}{
-	{DumpHeaders, "headers"},
-	{DumpBodies, "bodies"},
-	{DumpRequests, "requests"},
-	{DumpResponses, "responses"},
-	{DumpAuth, "auth"},
-	{DumpFilters, "filters"},
-	{DumpGoRoutines, "goroutines"},
-	{DumpOpenFiles, "openfiles"},
+type dumpChoices struct{}
+
+func (dumpChoices) Choices() []BitsChoicesInfo {
+	return []BitsChoicesInfo{
+		{uint64(DumpHeaders), "headers"},
+		{uint64(DumpBodies), "bodies"},
+		{uint64(DumpRequests), "requests"},
+		{uint64(DumpResponses), "responses"},
+		{uint64(DumpAuth), "auth"},
+		{uint64(DumpFilters), "filters"},
+		{uint64(DumpGoRoutines), "goroutines"},
+		{uint64(DumpOpenFiles), "openfiles"},
+	}
 }
 
-// DumpFlagsList is a list of dump flags used in the help
-var DumpFlagsList string
-
-func init() {
-	// calculate the dump flags list
-	var out []string
-	for _, info := range dumpFlags {
-		out = append(out, info.name)
-	}
-	DumpFlagsList = strings.Join(out, ",")
-}
-
-// String turns a DumpFlags into a string
-func (f DumpFlags) String() string {
-	var out []string
-	for _, info := range dumpFlags {
-		if f&info.flag != 0 {
-			out = append(out, info.name)
-			f &^= info.flag
-		}
-	}
-	if f != 0 {
-		out = append(out, fmt.Sprintf("Unknown-0x%X", int(f)))
-	}
-	return strings.Join(out, ",")
-}
-
-// Set a DumpFlags as a comma separated list of flags
-func (f *DumpFlags) Set(s string) error {
-	var flags DumpFlags
-	parts := strings.Split(s, ",")
-	for _, part := range parts {
-		found := false
-		part = strings.ToLower(strings.TrimSpace(part))
-		if part == "" {
-			continue
-		}
-		for _, info := range dumpFlags {
-			if part == info.name {
-				found = true
-				flags |= info.flag
-			}
-		}
-		if !found {
-			return fmt.Errorf("unknown dump flag %q", part)
-		}
-	}
-	*f = flags
-	return nil
-}
-
-// Type of the value
-func (f DumpFlags) Type() string {
+func (dumpChoices) Type() string {
 	return "DumpFlags"
 }
 
-// UnmarshalJSON makes sure the value can be parsed as a string or integer in JSON
-func (f *DumpFlags) UnmarshalJSON(in []byte) error {
-	return UnmarshalJSONFlag(in, f, func(i int64) error {
-		*f = (DumpFlags)(i)
-		return nil
-	})
-}
+// DumpFlagsList is a list of dump flags used in the help
+var DumpFlagsList = DumpHeaders.Help()

fs/dump_test.go

@@ -33,9 +33,9 @@ func TestDumpFlagsSet(t *testing.T) {
 		{"bodies,headers,auth", DumpBodies | DumpHeaders | DumpAuth, ""},
 		{"bodies,headers,auth", DumpBodies | DumpHeaders | DumpAuth, ""},
 		{"headers,bodies,requests,responses,auth,filters", DumpHeaders | DumpBodies | DumpRequests | DumpResponses | DumpAuth | DumpFilters, ""},
-		{"headers,bodies,unknown,auth", 0, "unknown dump flag \"unknown\""},
+		{"headers,bodies,unknown,auth", 0, "invalid choice \"unknown\""},
 	} {
-		f := DumpFlags(-1)
+		f := DumpFlags(0xffffffffffffffff)
 		initial := f
 		err := f.Set(test.in)
 		if err != nil {
@@ -72,12 +72,12 @@ func TestDumpFlagsUnmarshallJSON(t *testing.T) {
 		{`"bodies,headers,auth"`, DumpBodies | DumpHeaders | DumpAuth, ""},
 		{`"bodies,headers,auth"`, DumpBodies | DumpHeaders | DumpAuth, ""},
 		{`"headers,bodies,requests,responses,auth,filters"`, DumpHeaders | DumpBodies | DumpRequests | DumpResponses | DumpAuth | DumpFilters, ""},
-		{`"headers,bodies,unknown,auth"`, 0, "unknown dump flag \"unknown\""},
+		{`"headers,bodies,unknown,auth"`, 0, "invalid choice \"unknown\""},
 		{`0`, DumpFlags(0), ""},
 		{strconv.Itoa(int(DumpBodies)), DumpBodies, ""},
 		{strconv.Itoa(int(DumpBodies | DumpHeaders | DumpAuth)), DumpBodies | DumpHeaders | DumpAuth, ""},
 	} {
-		f := DumpFlags(-1)
+		f := DumpFlags(0xffffffffffffffff)
 		initial := f
 		err := json.Unmarshal([]byte(test.in), &f)
 		if err != nil {