Initial commit

vendor/github.com/hyperhq/hypercli/daemon/logger/factory.go

@@ -0,0 +1,89 @@
+package logger
+
+import (
+	"fmt"
+	"sync"
+)
+
+// Creator builds a logging driver instance with given context.
+type Creator func(Context) (Logger, error)
+
+// LogOptValidator checks the options specific to the underlying
+// logging implementation.
+type LogOptValidator func(cfg map[string]string) error
+
+type logdriverFactory struct {
+	registry     map[string]Creator
+	optValidator map[string]LogOptValidator
+	m            sync.Mutex
+}
+
+func (lf *logdriverFactory) register(name string, c Creator) error {
+	lf.m.Lock()
+	defer lf.m.Unlock()
+
+	if _, ok := lf.registry[name]; ok {
+		return fmt.Errorf("logger: log driver named '%s' is already registered", name)
+	}
+	lf.registry[name] = c
+	return nil
+}
+
+func (lf *logdriverFactory) registerLogOptValidator(name string, l LogOptValidator) error {
+	lf.m.Lock()
+	defer lf.m.Unlock()
+
+	if _, ok := lf.optValidator[name]; ok {
+		return fmt.Errorf("logger: log validator named '%s' is already registered", name)
+	}
+	lf.optValidator[name] = l
+	return nil
+}
+
+func (lf *logdriverFactory) get(name string) (Creator, error) {
+	lf.m.Lock()
+	defer lf.m.Unlock()
+
+	c, ok := lf.registry[name]
+	if !ok {
+		return c, fmt.Errorf("logger: no log driver named '%s' is registered", name)
+	}
+	return c, nil
+}
+
+func (lf *logdriverFactory) getLogOptValidator(name string) LogOptValidator {
+	lf.m.Lock()
+	defer lf.m.Unlock()
+
+	c, _ := lf.optValidator[name]
+	return c
+}
+
+var factory = &logdriverFactory{registry: make(map[string]Creator), optValidator: make(map[string]LogOptValidator)} // global factory instance
+
+// RegisterLogDriver registers the given logging driver builder with given logging
+// driver name.
+func RegisterLogDriver(name string, c Creator) error {
+	return factory.register(name, c)
+}
+
+// RegisterLogOptValidator registers the logging option validator with
+// the given logging driver name.
+func RegisterLogOptValidator(name string, l LogOptValidator) error {
+	return factory.registerLogOptValidator(name, l)
+}
+
+// GetLogDriver provides the logging driver builder for a logging driver name.
+func GetLogDriver(name string) (Creator, error) {
+	return factory.get(name)
+}
+
+// ValidateLogOpts checks the options for the given log driver. The
+// options supported are specific to the LogDriver implementation.
+func ValidateLogOpts(name string, cfg map[string]string) error {
+	l := factory.getLogOptValidator(name)
+	if l != nil {
+		return l(cfg)
+	}
+	return nil
+}