Mark values with scope, such as system, global, self

After mark values with scope, we can filter config values in order to
show config variables of specific scope.

Signed-off-by: Jiang Xin <zhiyou.jx@alibaba-inc.com>

git-config.go

@@ -1,15 +1,69 @@
 package goconfig
 
 import (
+	"sort"
 	"strconv"
 	"strings"
 )
 
+// Scope is used to mark where config variable comes from
+type Scope int
+
+// Define scopes for config variables
+const (
+	ScopeInclude = 1 << iota
+	ScopeSystem
+	ScopeGlobal
+	ScopeSelf
+
+	ScopeAll  = 0xFFFF
+	ScopeMask = ^ScopeInclude
+)
+
+// String show user friendly display of scope
+func (v *Scope) String() string {
+	i := int(*v)
+	inc := ""
+	if i&ScopeInclude == ScopeInclude {
+		inc = "-inc"
+	}
+
+	if i&ScopeSystem == ScopeSystem {
+		return "system" + inc
+	} else if i&ScopeGlobal == ScopeGlobal {
+		return "global" + inc
+	} else if i&ScopeSelf == ScopeSelf {
+		return "self" + inc
+	}
+	return "unknown" + inc
+}
+
 // GitConfig maps section to key-value pairs
 type GitConfig map[string]GitConfigKeys
 
 // GitConfigKeys maps key to values
-type GitConfigKeys map[string][]string
+type GitConfigKeys map[string][]*GitConfigValue
+
+// GitConfigValue holds value and its scope
+type GitConfigValue struct {
+	scope Scope
+	value string
+}
+
+// Set is used to set value
+func (v *GitConfigValue) Set(value string) {
+	v.value = value
+}
+
+// Value is used to show value
+func (v *GitConfigValue) Value() string {
+	return v.value
+}
+
+// Scope is used to show user friendly scope
+func (v *GitConfigValue) Scope() string {
+	return v.scope.String()
+}
 
 // NewGitConfig returns GitConfig with initialized maps
 func NewGitConfig() GitConfig {
@@ -25,6 +79,7 @@ func (v GitConfig) Keys() []string {
 			allKeys = append(allKeys, s+"."+key)
 		}
 	}
+	sort.Strings(allKeys)
 	return allKeys
 }
 
@@ -42,9 +97,9 @@ func (v GitConfig) _add(section, key, value string) {
 	}
 
 	if _, ok := v[section][key]; !ok {
-		v[section][key] = []string{}
+		v[section][key] = []*GitConfigValue{}
 	}
-	v[section][key] = append(v[section][key], value)
+	v[section][key] = append(v[section][key], &GitConfigValue{value: value})
 }
 
 // Get value from key
@@ -106,9 +161,25 @@ func (v GitConfig) GetUint64(key string, defaultValue uint64) (uint64, error) {
 func (v GitConfig) GetAll(key string) []string {
 	section, key := toSectionKey(key)
 
-	keys := v[section]
-	if keys != nil {
-		return keys[key]
+	values := []string{}
+
+	if v[section] != nil && v[section][key] != nil {
+		for _, value := range v[section][key] {
+			if value != nil {
+				values = append(values, value.value)
+			}
+		}
+		return values
+	}
+	return nil
+}
+
+// GetRaw gets all values of a key
+func (v GitConfig) GetRaw(key string) []*GitConfigValue {
+	section, key := toSectionKey(key)
+
+	if v[section] != nil && v[section][key] != nil {
+		return v[section][key]
 	}
 	return nil
 }
@@ -141,16 +212,26 @@ func toSectionKey(name string) (string, string) {
 
 // Merge will merge another GitConfig, and new value(s) of the same key will
 // append to the end of value list, and new value has higher priority.
-func (v GitConfig) Merge(c GitConfig) GitConfig {
+func (v GitConfig) Merge(c GitConfig, scope Scope) GitConfig {
 	for sec, keys := range c {
 		if _, ok := v[sec]; !ok {
 			v[sec] = make(GitConfigKeys)
 		}
 		for key, values := range keys {
 			if v[sec][key] == nil {
-				v[sec][key] = []string{}
+				v[sec][key] = []*GitConfigValue{}
+			}
+			for _, value := range values {
+				if value == nil {
+					continue
+				}
+				v[sec][key] = append(v[sec][key],
+					&GitConfigValue{
+						scope: (value.scope & ^ScopeMask) | scope,
+						value: value.Value(),
+					})
+
 			}
-			v[sec][key] = append(v[sec][key], values...)
 		}
 	}
 	return v

git-config_test.go

@@ -1,6 +1,7 @@
 package goconfig
 
 import (
+	"fmt"
 	"testing"
 
 	"github.com/stretchr/testify/assert"
@@ -182,7 +183,7 @@ func TestMerge(t *testing.T) {
 	assert.Equal("other-c", cfg2.Get("a.c"))
 	assert.Equal("other-d", cfg2.Get("a.d"))
 
-	cfg.Merge(cfg2)
+	cfg.Merge(cfg2, ScopeInclude)
 	assert.Equal("value-b", cfg.Get("a.b"))
 	assert.Equal("other-c", cfg.Get("a.c"))
 	assert.Equal("other-d", cfg.Get("a.d"))
@@ -191,3 +192,56 @@ func TestMerge(t *testing.T) {
 		"other-c",
 	}, cfg.GetAll("a.c"))
 }
+
+func TestScope(t *testing.T) {
+	assert := assert.New(t)
+	assert.Equal(0x1, ScopeInclude)
+	assert.Equal(^0x1, ScopeMask)
+}
+
+func ExampleMerge() {
+	sys := NewGitConfig()
+	sys.Add("sect1.Name1", "value-1.1.1")
+	sys.Add("sect1.Name2", "value-1.1.2")
+
+	inc1 := NewGitConfig()
+	inc1.Add("sect1.Name3", "value-0.1.3")
+	inc1.Add("sect2.name1", "value-0.2.1")
+
+	sys.Merge(inc1, ScopeInclude)
+
+	global := NewGitConfig()
+	global.Add("sect1.name2", "value-2.1.2")
+	global.Add("sect1.name3", "value-2.1.3")
+	global.Add("sect1.name4", "value-2.1.4")
+	global.Add("sect3.name1", "value-2.3.1")
+
+	repo := NewGitConfig()
+	repo.Add("sect1.name2", "value-3.1.2")
+	repo.Add("sect1.name3", "value-3.1.3")
+	repo.Add("sect1.name4", "value-3.1.4")
+
+	all := NewGitConfig()
+	all.Merge(sys, ScopeSystem)
+	all.Merge(global, ScopeGlobal)
+	all.Merge(repo, ScopeSelf)
+
+	fmt.Println()
+	for _, k := range all.Keys() {
+		for _, value := range all.GetRaw(k) {
+			fmt.Printf("%s = %-8s (%s)\n", k, value.Value(), value.Scope())
+		}
+	}
+	// Output:
+	// sect1.name1 = value-1.1.1 (system)
+	// sect1.name2 = value-1.1.2 (system)
+	// sect1.name2 = value-2.1.2 (global)
+	// sect1.name2 = value-3.1.2 (self)
+	// sect1.name3 = value-0.1.3 (system-inc)
+	// sect1.name3 = value-2.1.3 (global)
+	// sect1.name3 = value-3.1.3 (self)
+	// sect1.name4 = value-2.1.4 (global)
+	// sect1.name4 = value-3.1.4 (self)
+	// sect2.name1 = value-0.2.1 (system-inc)
+	// sect3.name1 = value-2.3.1 (global)
+}

goconfig.go

@@ -103,7 +103,7 @@ func (cf *parser) parse() (GitConfig, error) {
 				if err != nil {
 					return cfg, err
 				}
-				cfg.Merge(config)
+				cfg.Merge(config, ScopeInclude)
 			}
 		}
 	}

load.go

@@ -116,15 +116,15 @@ func loadAll(name string, searching bool) (GitConfig, error) {
 	}
 
 	if sysConfig != nil {
-		cfg.Merge(sysConfig)
+		cfg.Merge(sysConfig, ScopeSystem)
 	}
 
 	if globalConfig != nil {
-		cfg.Merge(globalConfig)
+		cfg.Merge(globalConfig, ScopeGlobal)
 	}
 
 	if repoConfig != nil {
-		cfg.Merge(repoConfig)
+		cfg.Merge(repoConfig, ScopeSelf)
 	}
 
 	return cfg, nil