github.com/adnan-c/fabric_e2e_couchdb@v0.6.1-preview.0.20170228180935-21ce6b23cf91/core/ledger/ledgermgmt/ledger_mgmt.go (about)

     1  /*
     2  Copyright IBM Corp. 2016 All Rights Reserved.
     3  
     4  Licensed under the Apache License, Version 2.0 (the "License");
     5  you may not use this file except in compliance with the License.
     6  You may obtain a copy of the License at
     7  
     8  		 http://www.apache.org/licenses/LICENSE-2.0
     9  
    10  Unless required by applicable law or agreed to in writing, software
    11  distributed under the License is distributed on an "AS IS" BASIS,
    12  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
    13  See the License for the specific language governing permissions and
    14  limitations under the License.
    15  */
    16  
    17  package ledgermgmt
    18  
    19  import (
    20  	"errors"
    21  	"sync"
    22  
    23  	"fmt"
    24  
    25  	"github.com/hyperledger/fabric/core/ledger"
    26  	"github.com/hyperledger/fabric/core/ledger/kvledger"
    27  	logging "github.com/op/go-logging"
    28  )
    29  
    30  var logger = logging.MustGetLogger("ledgermgmt")
    31  
    32  // ErrLedgerAlreadyOpened is thrown by a CreateLedger call if a ledger with the given id is already opened
    33  var ErrLedgerAlreadyOpened = errors.New("Ledger already opened")
    34  
    35  // ErrLedgerMgmtNotInitialized is thrown when ledger mgmt is used before initializing this
    36  var ErrLedgerMgmtNotInitialized = errors.New("ledger mgmt should be initialized before using")
    37  
    38  var openedLedgers map[string]ledger.PeerLedger
    39  var ledgerProvider ledger.PeerLedgerProvider
    40  var lock sync.Mutex
    41  var initialized bool
    42  var once sync.Once
    43  
    44  // Initialize initializes ledgermgmt
    45  func Initialize() {
    46  	once.Do(func() {
    47  		initialize()
    48  	})
    49  }
    50  
    51  func initialize() {
    52  	logger.Info("Initializing ledger mgmt")
    53  	lock.Lock()
    54  	defer lock.Unlock()
    55  	initialized = true
    56  	openedLedgers = make(map[string]ledger.PeerLedger)
    57  	provider, err := kvledger.NewProvider()
    58  	if err != nil {
    59  		panic(fmt.Errorf("Error in instantiating ledger provider: %s", err))
    60  	}
    61  	ledgerProvider = provider
    62  	logger.Info("ledger mgmt initialized")
    63  }
    64  
    65  // CreateLedger creates a new ledger with the given id
    66  func CreateLedger(id string) (ledger.PeerLedger, error) {
    67  	logger.Infof("Creating leadger with id = %s", id)
    68  	lock.Lock()
    69  	defer lock.Unlock()
    70  	if !initialized {
    71  		return nil, ErrLedgerMgmtNotInitialized
    72  	}
    73  	l, err := ledgerProvider.Create(id)
    74  	if err != nil {
    75  		return nil, err
    76  	}
    77  	l = wrapLedger(id, l)
    78  	openedLedgers[id] = l
    79  	logger.Infof("Created leadger with id = %s", id)
    80  	return l, nil
    81  }
    82  
    83  // OpenLedger returns a ledger for the given id
    84  func OpenLedger(id string) (ledger.PeerLedger, error) {
    85  	logger.Infof("Opening leadger with id = %s", id)
    86  	lock.Lock()
    87  	defer lock.Unlock()
    88  	if !initialized {
    89  		return nil, ErrLedgerMgmtNotInitialized
    90  	}
    91  	l, ok := openedLedgers[id]
    92  	if ok {
    93  		return nil, ErrLedgerAlreadyOpened
    94  	}
    95  	l, err := ledgerProvider.Open(id)
    96  	if err != nil {
    97  		return nil, err
    98  	}
    99  	l = wrapLedger(id, l)
   100  	openedLedgers[id] = l
   101  	logger.Infof("Opened leadger with id = %s", id)
   102  	return l, nil
   103  }
   104  
   105  // GetLedgerIDs returns the ids of the ledgers created
   106  func GetLedgerIDs() ([]string, error) {
   107  	lock.Lock()
   108  	defer lock.Unlock()
   109  	if !initialized {
   110  		return nil, ErrLedgerMgmtNotInitialized
   111  	}
   112  	return ledgerProvider.List()
   113  }
   114  
   115  // Close closes all the opened ledgers and any resources held for ledger management
   116  func Close() {
   117  	logger.Infof("Closing ledger mgmt")
   118  	lock.Lock()
   119  	defer lock.Unlock()
   120  	if !initialized {
   121  		return
   122  	}
   123  	for _, l := range openedLedgers {
   124  		l.(*closableLedger).closeWithoutLock()
   125  	}
   126  	ledgerProvider.Close()
   127  	openedLedgers = nil
   128  	logger.Infof("ledger mgmt closed")
   129  }
   130  
   131  func wrapLedger(id string, l ledger.PeerLedger) ledger.PeerLedger {
   132  	return &closableLedger{id, l}
   133  }
   134  
   135  // closableLedger extends from actual validated ledger and overwrites the Close method
   136  type closableLedger struct {
   137  	id string
   138  	ledger.PeerLedger
   139  }
   140  
   141  // Close closes the actual ledger and removes the entries from opened ledgers map
   142  func (l *closableLedger) Close() {
   143  	lock.Lock()
   144  	defer lock.Unlock()
   145  	l.closeWithoutLock()
   146  }
   147  
   148  func (l *closableLedger) closeWithoutLock() {
   149  	l.PeerLedger.Close()
   150  	delete(openedLedgers, l.id)
   151  }