github.com/unigraph-dev/dgraph@v1.1.1-0.20200923154953-8b52b426f765/systest/_customtok/cidr/main.go (about)

     1  /*
     2   * Copyright 2017-2018 Dgraph Labs, Inc. and Contributors
     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 main
    18  
    19  import "net"
    20  
    21  func Tokenizer() interface{} { return CIDRTokenizer{} }
    22  
    23  type CIDRTokenizer struct{}
    24  
    25  func (CIDRTokenizer) Name() string     { return "cidr" }
    26  func (CIDRTokenizer) Type() string     { return "string" }
    27  func (CIDRTokenizer) Identifier() byte { return 0xff }
    28  
    29  func (t CIDRTokenizer) Tokens(value interface{}) ([]string, error) {
    30  	_, ipnet, err := net.ParseCIDR(value.(string))
    31  	if err != nil {
    32  		return nil, err
    33  	}
    34  	ones, bits := ipnet.Mask.Size()
    35  	var toks []string
    36  	for i := ones; i >= 1; i-- {
    37  		m := net.CIDRMask(i, bits)
    38  		tok := net.IPNet{
    39  			IP:   ipnet.IP.Mask(m),
    40  			Mask: m,
    41  		}
    42  		toks = append(toks, tok.String())
    43  	}
    44  	return toks, nil
    45  }