github.com/datachainlab/burrow@v0.25.0/execution/names/names.go (about)

     1  // Copyright 2017 Monax Industries Limited
     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 names
    16  
    17  import (
    18  	"fmt"
    19  
    20  	"github.com/hyperledger/burrow/event/query"
    21  	amino "github.com/tendermint/go-amino"
    22  )
    23  
    24  var MinNameRegistrationPeriod uint64 = 5
    25  
    26  const (
    27  
    28  	// NOTE: base costs and validity checks are here so clients
    29  	// can use them without importing state
    30  
    31  	// cost for storing a name for a block is
    32  	// CostPerBlock*CostPerByte*(len(data) + 32)
    33  	NameByteCostMultiplier  uint64 = 1
    34  	NameBlockCostMultiplier uint64 = 1
    35  
    36  	MaxNameLength = 64
    37  	MaxDataLength = 1 << 16
    38  )
    39  
    40  var cdc = amino.NewCodec()
    41  
    42  func (e *Entry) Encode() ([]byte, error) {
    43  	return cdc.MarshalBinaryBare(e)
    44  }
    45  
    46  func (e *Entry) String() string {
    47  	return fmt.Sprintf("NameEntry{%v -> %v; Expires: %v, Owner: %v}", e.Name, e.Data, e.Expires, e.Owner)
    48  }
    49  
    50  type TaggedEntry struct {
    51  	*Entry
    52  	query.Tagged
    53  }
    54  
    55  func (e *Entry) Tagged() *TaggedEntry {
    56  	return &TaggedEntry{
    57  		Entry:  e,
    58  		Tagged: query.MustReflectTags(e),
    59  	}
    60  }
    61  
    62  func DecodeEntry(entryBytes []byte) (*Entry, error) {
    63  	entry := new(Entry)
    64  	err := cdc.UnmarshalBinaryBare(entryBytes, entry)
    65  	if err != nil {
    66  		return nil, err
    67  	}
    68  	return entry, nil
    69  }
    70  
    71  type Reader interface {
    72  	GetName(name string) (*Entry, error)
    73  }
    74  
    75  type Writer interface {
    76  	// Updates the name entry creating it if it does not exist
    77  	UpdateName(entry *Entry) error
    78  	// Remove the name entry
    79  	RemoveName(name string) error
    80  }
    81  
    82  type ReaderWriter interface {
    83  	Reader
    84  	Writer
    85  }
    86  
    87  type Iterable interface {
    88  	IterateNames(consumer func(*Entry) error) (err error)
    89  }
    90  
    91  type IterableReader interface {
    92  	Iterable
    93  	Reader
    94  }
    95  
    96  type IterableReaderWriter interface {
    97  	Iterable
    98  	ReaderWriter
    99  }
   100  
   101  // base cost is "effective" number of bytes
   102  func NameBaseCost(name, data string) uint64 {
   103  	return uint64(len(data) + 32)
   104  }
   105  
   106  func NameCostPerBlock(baseCost uint64) uint64 {
   107  	return NameBlockCostMultiplier * NameByteCostMultiplier * baseCost
   108  }
   109  
   110  func NameCostForExpiryIn(name, data string, expiresIn uint64) uint64 {
   111  	return NameCostPerBlock(NameBaseCost(name, data)) * expiresIn
   112  }