feat: cache capabilities

src/concurrent_map.go

@@ -0,0 +1,30 @@
+package main
+
+import "sync"
+
+type concurrentMap struct {
+	values map[string]string
+	lock   sync.RWMutex
+}
+
+func newConcurrentMap() *concurrentMap {
+	return &concurrentMap{
+		values: make(map[string]string),
+		lock:   sync.RWMutex{},
+	}
+}
+
+func (c *concurrentMap) set(key, value string) {
+	c.lock.Lock()
+	defer c.lock.Unlock()
+	c.values[key] = value
+}
+
+func (c *concurrentMap) get(key string) (string, bool) {
+	c.lock.RLock()
+	defer c.lock.RUnlock()
+	if val, ok := c.values[key]; ok {
+		return val, true
+	}
+	return "", false
+}

src/environment.go

@@ -48,6 +48,13 @@ type fileInfo struct {
 	isDir        bool
 }
 
+type cache interface {
+	init(home string)
+	close()
+	get(key string) (string, bool)
+	set(key, value string)
+}
+
 type environmentInfo interface {
 	getenv(key string) string
 	getcwd() string
@@ -77,6 +84,8 @@ type environmentInfo interface {
 	isWsl() bool
 	stackCount() int
 	getTerminalWidth() (int, error)
+	cache() cache
+	close()
 }
 
 type commandCache struct {
@@ -131,6 +140,7 @@ type environment struct {
 	args      *args
 	cwd       string
 	cmdCache  *commandCache
+	fileCache *fileCache
 	tracer    *tracer
 }
 
@@ -139,6 +149,8 @@ func (env *environment) init(args *args) {
 	env.cmdCache = &commandCache{
 		commands: newConcurrentMap(),
 	}
+	env.fileCache = &fileCache{}
+	env.fileCache.init(env.homeDir())
 	tracer := &tracer{
 		debug: *args.Debug,
 	}
@@ -461,6 +473,15 @@ func (env *environment) stackCount() int {
 	return *env.args.StackCount
 }
 
+func (env *environment) cache() cache {
+	return env.fileCache
+}
+
+func (env *environment) close() {
+	env.fileCache.close()
+	env.tracer.close()
+}
+
 func cleanHostName(hostName string) string {
 	garbage := []string{
 		".lan",

src/environment_cache.go

@@ -0,0 +1,49 @@
+package main
+
+import (
+	"fmt"
+	"io/ioutil"
+	"strings"
+)
+
+const (
+	cachePath = "/.omp.cache"
+)
+
+type fileCache struct {
+	cache *concurrentMap
+	home  string
+}
+
+func (fc *fileCache) init(home string) {
+	fc.cache = newConcurrentMap()
+	fc.home = home
+	content, err := ioutil.ReadFile(home + cachePath)
+	if err != nil {
+		return
+	}
+	for _, line := range strings.Split(string(content), "\n") {
+		if len(line) == 0 || !strings.Contains(line, "=") {
+			continue
+		}
+		kv := strings.SplitN(line, "=", 2)
+		fc.set(kv[0], kv[1])
+	}
+}
+
+func (fc *fileCache) close() {
+	var sb strings.Builder
+	for key, value := range fc.cache.values {
+		cacheEntry := fmt.Sprintf("%s=%s\n", key, value)
+		sb.WriteString(cacheEntry)
+	}
+	_ = ioutil.WriteFile(fc.home+cachePath, []byte(sb.String()), 0644)
+}
+
+func (fc *fileCache) get(key string) (string, bool) {
+	return fc.cache.get(key)
+}
+
+func (fc *fileCache) set(key, value string) {
+	fc.cache.set(key, value)
+}

src/main.go

@@ -160,7 +160,7 @@ func main() {
 	flag.Parse()
 	env := &environment{}
 	env.init(args)
-	defer env.tracer.close()
+	defer env.close()
 	if *args.Millis {
 		fmt.Print(time.Now().UnixNano() / 1000000)
 		return

src/segment_path_test.go

@@ -153,6 +153,15 @@ func (env *MockedEnvironment) getTerminalWidth() (int, error) {
 	return args.Int(0), args.Error(1)
 }
 
+func (env *MockedEnvironment) cache() cache {
+	args := env.Called(nil)
+	return args.Get(0).(cache)
+}
+
+func (env *MockedEnvironment) close() {
+	_ = env.Called(nil)
+}
+
 const (
 	homeBill        = "/home/bill"
 	homeJan         = "/usr/home/jan"