github.com/letsencrypt/trillian@v1.1.2-0.20180615153820-ae375a99d36a/storage/tree_id.go (about)

     1  // Copyright 2017 Google Inc. All Rights Reserved.
     2  //
     3  // Licensed under the Apache License, Version 2.0 (the "License");
     4  // you may not use this file except in compliance with the License.
     5  // You may obtain a copy of the License at
     6  //
     7  //     http://www.apache.org/licenses/LICENSE-2.0
     8  //
     9  // Unless required by applicable law or agreed to in writing, software
    10  // distributed under the License is distributed on an "AS IS" BASIS,
    11  // WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
    12  // See the License for the specific language governing permissions and
    13  // limitations under the License.
    14  
    15  package storage
    16  
    17  import (
    18  	"crypto/rand"
    19  	"math"
    20  	"math/big"
    21  )
    22  
    23  // NewTreeID generates a random, positive, non-zero tree ID.
    24  func NewTreeID() (int64, error) {
    25  	id, err := rand.Int(rand.Reader, big.NewInt(math.MaxInt64))
    26  	if err != nil {
    27  		return 0, err
    28  	}
    29  	return id.Int64() + 1, nil
    30  }