client.go

/*
Licensed to the Apache Software Foundation (ASF) under one
or more contributor license agreements.  See the NOTICE file
distributed with this work for additional information
regarding copyright ownership.  The ASF licenses this file
to you under the Apache License, Version 2.0 (the
"License"); you may not use this file except in compliance
with the License.  You may obtain a copy of the License at

  http://www.apache.org/licenses/LICENSE-2.0

Unless required by applicable law or agreed to in writing,
software distributed under the License is distributed on an
"AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
KIND, either express or implied.  See the License for the
specific language governing permissions and limitations
under the License.
*/

package crypto

import (
	"github.com/openblockchain/obc-peer/openchain/crypto/utils"
	"sync"
)

// Private Variables

type clientEntry struct {
	client  Client
	counter int64
}

var (
	// Map of initialized clients
	clients = make(map[string]clientEntry)

	// Sync
	clientMutex sync.Mutex
)

// Public Methods

// RegisterClient registers a client to the PKI infrastructure
func RegisterClient(name string, pwd []byte, enrollID, enrollPWD string) error {
	clientMutex.Lock()
	defer clientMutex.Unlock()

	log.Info("Registering client [%s] with name [%s]...", enrollID, name)

	if _, ok := clients[name]; ok {
		log.Info("Registering client [%s] with name [%s]...done. Already initialized.", enrollID, name)

		return nil
	}

	client := new(clientImpl)
	if err := client.register(name, pwd, enrollID, enrollPWD); err != nil {
		if err != utils.ErrAlreadyRegistered && err != utils.ErrAlreadyInitialized {
			log.Error("Failed registering client [%s] with name [%s] [%s].", enrollID, name, err)
			return err
		}
		log.Info("Registering client [%s] with name [%s]...done. Already registered or initiliazed.", enrollID, name)
	}
	err := client.close()
	if err != nil {
		// It is not necessary to report this error to the caller
		log.Warning("Registering client [%s] with name [%s]. Failed closing [%s].", enrollID, name, err)
	}

	log.Info("Registering client [%s] with name [%s]...done!", enrollID, name)

	return nil
}

// InitClient initializes a client named name with password pwd
func InitClient(name string, pwd []byte) (Client, error) {
	clientMutex.Lock()
	defer clientMutex.Unlock()

	log.Info("Initializing client [%s]...", name)

	if entry, ok := clients[name]; ok {
		log.Info("Client already initiliazied [%s]. Increasing counter from [%d]", name, clients[name].counter)
		entry.counter++
		clients[name] = entry

		return clients[name].client, nil
	}

	client := new(clientImpl)
	if err := client.init(name, pwd); err != nil {
		log.Error("Failed client initialization [%s]: [%s].", name, err)

		return nil, err
	}

	clients[name] = clientEntry{client, 1}
	log.Info("Initializing client [%s]...done!", name)

	return client, nil
}

// CloseClient releases all the resources allocated by clients
func CloseClient(client Client) error {
	clientMutex.Lock()
	defer clientMutex.Unlock()

	return closeClientInternal(client, false)
}

// CloseAllClients closes all the clients initialized so far
func CloseAllClients() (bool, []error) {
	clientMutex.Lock()
	defer clientMutex.Unlock()

	log.Info("Closing all clients...")

	errs := make([]error, len(clients))
	for _, value := range clients {
		err := closeClientInternal(value.client, true)

		errs = append(errs, err)
	}

	log.Info("Closing all clients...done!")

	return len(errs) != 0, errs
}

// Private Methods

func closeClientInternal(client Client, force bool) error {
	if client == nil {
		return utils.ErrNilArgument
	}

	name := client.GetName()
	log.Info("Closing client [%s]...", name)
	entry, ok := clients[name]
	if !ok {
		return utils.ErrInvalidReference
	}
	if entry.counter == 1 || force {
		defer delete(clients, name)
		err := clients[name].client.(*clientImpl).close()
		log.Info("Closing client [%s]...done! [%s].", name, utils.ErrToString(err))
		return err
	} else {
		// decrease counter
		entry.counter--
		clients[name] = entry
		log.Info("Closing client [%s]...decreased counter at [%d].", name, clients[name].counter)
	}

	return nil
}