forked from TrueCloudLab/neoneo-go
176 lines
4.1 KiB
Go
176 lines
4.1 KiB
Go
package storage
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import (
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"bytes"
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"sort"
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"strings"
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"sync"
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"github.com/nspcc-dev/neo-go/pkg/util/slice"
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)
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// MemoryStore is an in-memory implementation of a Store, mainly
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// used for testing. Do not use MemoryStore in production.
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type MemoryStore struct {
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mut sync.RWMutex
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mem map[string][]byte
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// A map, not a slice, to avoid duplicates.
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del map[string]bool
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}
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// MemoryBatch is an in-memory batch compatible with MemoryStore.
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type MemoryBatch struct {
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MemoryStore
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}
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// Put implements the Batch interface.
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func (b *MemoryBatch) Put(k, v []byte) {
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b.MemoryStore.put(string(k), slice.Copy(v))
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}
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// Delete implements Batch interface.
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func (b *MemoryBatch) Delete(k []byte) {
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b.MemoryStore.drop(string(k))
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}
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// NewMemoryStore creates a new MemoryStore object.
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func NewMemoryStore() *MemoryStore {
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return &MemoryStore{
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mem: make(map[string][]byte),
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del: make(map[string]bool),
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}
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}
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// Get implements the Store interface.
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func (s *MemoryStore) Get(key []byte) ([]byte, error) {
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s.mut.RLock()
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defer s.mut.RUnlock()
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if val, ok := s.mem[string(key)]; ok {
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return val, nil
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}
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return nil, ErrKeyNotFound
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}
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// put puts a key-value pair into the store, it's supposed to be called
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// with mutex locked.
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func (s *MemoryStore) put(key string, value []byte) {
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s.mem[key] = value
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delete(s.del, key)
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}
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// Put implements the Store interface. Never returns an error.
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func (s *MemoryStore) Put(key, value []byte) error {
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newKey := string(key)
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vcopy := slice.Copy(value)
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s.mut.Lock()
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s.put(newKey, vcopy)
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s.mut.Unlock()
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return nil
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}
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// drop deletes a key-value pair from the store, it's supposed to be called
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// with mutex locked.
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func (s *MemoryStore) drop(key string) {
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s.del[key] = true
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delete(s.mem, key)
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}
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// Delete implements Store interface. Never returns an error.
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func (s *MemoryStore) Delete(key []byte) error {
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newKey := string(key)
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s.mut.Lock()
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s.drop(newKey)
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s.mut.Unlock()
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return nil
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}
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// PutBatch implements the Store interface. Never returns an error.
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func (s *MemoryStore) PutBatch(batch Batch) error {
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b := batch.(*MemoryBatch)
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return s.PutChangeSet(b.mem, b.del)
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}
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// PutChangeSet implements the Store interface. Never returns an error.
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func (s *MemoryStore) PutChangeSet(puts map[string][]byte, dels map[string]bool) error {
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s.mut.Lock()
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for k := range puts {
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s.put(k, puts[k])
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}
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for k := range dels {
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s.drop(k)
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}
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s.mut.Unlock()
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return nil
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}
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// Seek implements the Store interface.
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func (s *MemoryStore) Seek(rng SeekRange, f func(k, v []byte)) {
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s.mut.RLock()
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s.seek(rng, f)
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s.mut.RUnlock()
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}
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// SeekAll is like seek but also iterates over deleted items.
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func (s *MemoryStore) SeekAll(key []byte, f func(k, v []byte)) {
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s.mut.RLock()
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defer s.mut.RUnlock()
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sk := string(key)
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for k, v := range s.mem {
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if strings.HasPrefix(k, sk) {
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f([]byte(k), v)
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}
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}
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for k := range s.del {
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if strings.HasPrefix(k, sk) {
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f([]byte(k), nil)
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}
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}
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}
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// seek is an internal unlocked implementation of Seek. `start` denotes whether
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// seeking starting from the provided prefix should be performed.
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func (s *MemoryStore) seek(rng SeekRange, f func(k, v []byte)) {
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sPrefix := string(rng.Prefix)
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lPrefix := len(sPrefix)
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sStart := string(rng.Start)
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lStart := len(sStart)
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var memList []KeyValue
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isKeyOK := func(key string) bool {
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return strings.HasPrefix(key, sPrefix) && (lStart == 0 || strings.Compare(key[lPrefix:], sStart) >= 0)
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}
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for k, v := range s.mem {
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if isKeyOK(k) {
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memList = append(memList, KeyValue{
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Key: []byte(k),
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Value: v,
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})
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}
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}
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sort.Slice(memList, func(i, j int) bool {
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return bytes.Compare(memList[i].Key, memList[j].Key) < 0
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})
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for _, kv := range memList {
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f(kv.Key, kv.Value)
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}
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}
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// Batch implements the Batch interface and returns a compatible Batch.
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func (s *MemoryStore) Batch() Batch {
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return newMemoryBatch()
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}
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// newMemoryBatch returns new memory batch.
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func newMemoryBatch() *MemoryBatch {
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return &MemoryBatch{MemoryStore: *NewMemoryStore()}
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}
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// Close implements Store interface and clears up memory. Never returns an
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// error.
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func (s *MemoryStore) Close() error {
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s.mut.Lock()
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s.del = nil
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s.mem = nil
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s.mut.Unlock()
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return nil
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}
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