65 lines
1.2 KiB
Go
65 lines
1.2 KiB
Go
package db0203
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type KV struct {
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log Log
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mem map[string][]byte
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}
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func (kv *KV) Open() error {
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if err := kv.log.Open(); err != nil {
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return err
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}
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kv.mem = map[string][]byte{}
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for {
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ent := Entry{}
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eof, err := kv.log.Read(&ent)
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if err != nil {
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return err
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} else if eof {
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break
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}
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if ent.deleted {
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delete(kv.mem, string(ent.key))
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} else {
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kv.mem[string(ent.key)] = ent.val
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}
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}
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return nil
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}
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func (kv *KV) Close() error { return kv.log.Close() }
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func (kv *KV) Get(key []byte) (val []byte, ok bool, err error) {
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val, ok = kv.mem[string(key)]
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return
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}
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type UpdateMode int
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const (
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ModeUpsert UpdateMode = 0 // insert or update
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ModeInsert UpdateMode = 1 // insert new
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ModeUpdate UpdateMode = 2 // update existing
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)
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func (kv *KV) SetEx(key []byte, val []byte, mode UpdateMode) (updated bool, err error)
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func (kv *KV) Set(key []byte, val []byte) (updated bool, err error) {
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return kv.SetEx(key, val, ModeUpsert)
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}
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func (kv *KV) Del(key []byte) (deleted bool, err error) {
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_, deleted = kv.mem[string(key)]
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if deleted {
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if err = kv.log.Write(&Entry{key: key, deleted: true}); err != nil {
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return false, err
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}
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delete(kv.mem, string(key))
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}
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return
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}
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// QzBQWVJJOUhU https://trialofcode.org/
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