neoneo-go/pkg/core/storage/helpers.go

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package storage
import (
"bytes"
"encoding/binary"
"sort"
"github.com/CityOfZion/neo-go/pkg/io"
"github.com/CityOfZion/neo-go/pkg/util"
)
// Version will attempt to get the current version stored in the
// underlying Store.
func Version(s Store) (string, error) {
version, err := s.Get(SYSVersion.Bytes())
return string(version), err
}
// PutVersion will store the given version in the underlying Store.
func PutVersion(s Store, v string) error {
return s.Put(SYSVersion.Bytes(), []byte(v))
}
// CurrentBlockHeight returns the current block height found in the
// underlying Store.
func CurrentBlockHeight(s Store) (uint32, error) {
b, err := s.Get(SYSCurrentBlock.Bytes())
if err != nil {
return 0, err
}
return binary.LittleEndian.Uint32(b[32:36]), nil
}
// CurrentHeaderHeight returns the current header height and hash from
// the underlying Store.
func CurrentHeaderHeight(s Store) (i uint32, h util.Uint256, err error) {
var b []byte
b, err = s.Get(SYSCurrentHeader.Bytes())
if err != nil {
return
}
i = binary.LittleEndian.Uint32(b[32:36])
h, err = util.Uint256DecodeReverseBytes(b[:32])
return
}
// uint32Slice attaches the methods of Interface to []int, sorting in increasing order.
type uint32Slice []uint32
func (p uint32Slice) Len() int { return len(p) }
func (p uint32Slice) Less(i, j int) bool { return p[i] < p[j] }
func (p uint32Slice) Swap(i, j int) { p[i], p[j] = p[j], p[i] }
// HeaderHashes returns a sorted list of header hashes retrieved from
// the given underlying Store.
func HeaderHashes(s Store) ([]util.Uint256, error) {
hashMap := make(map[uint32][]util.Uint256)
s.Seek(IXHeaderHashList.Bytes(), func(k, v []byte) {
storedCount := binary.LittleEndian.Uint32(k[1:])
hashes, err := read2000Uint256Hashes(v)
if err != nil {
panic(err)
}
hashMap[storedCount] = hashes
})
var (
hashes = make([]util.Uint256, 0, len(hashMap))
sortedKeys = make([]uint32, 0, len(hashMap))
)
for k := range hashMap {
sortedKeys = append(sortedKeys, k)
}
sort.Sort(uint32Slice(sortedKeys))
for _, key := range sortedKeys {
hashes = append(hashes[:key], hashMap[key]...)
}
return hashes, nil
}
// read2000Uint256Hashes attempts to read 2000 Uint256 hashes from
// the given byte array.
func read2000Uint256Hashes(b []byte) ([]util.Uint256, error) {
r := bytes.NewReader(b)
br := io.NewBinReaderFromIO(r)
lenHashes := br.ReadVarUint()
hashes := make([]util.Uint256, lenHashes)
br.ReadLE(hashes)
if br.Err != nil {
return nil, br.Err
}
return hashes, nil
}