79 lines
2.7 KiB
Go
79 lines
2.7 KiB
Go
// Copyright 2015 PingCAP, Inc.
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//
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// Licensed under the Apache License, Version 2.0 (the "License");
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// you may not use this file except in compliance with the License.
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// You may obtain a copy of the License at
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//
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// http://www.apache.org/licenses/LICENSE-2.0
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//
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// Unless required by applicable law or agreed to in writing, software
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// distributed under the License is distributed on an "AS IS" BASIS,
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// See the License for the specific language governing permissions and
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// limitations under the License.
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package kv
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import (
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"github.com/juju/errors"
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"github.com/pingcap/tidb/util/codec"
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)
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var (
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// ErrClosed is used when close an already closed txn.
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ErrClosed = errors.New("Error: Transaction already closed")
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// ErrNotExist is used when try to get an entry with an unexist key from KV store.
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ErrNotExist = errors.New("Error: key not exist")
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// ErrKeyExists is used when try to put an entry to KV store.
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ErrKeyExists = errors.New("Error: key already exist")
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// ErrConditionNotMatch is used when condition is not met.
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ErrConditionNotMatch = errors.New("Error: Condition not match")
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// ErrLockConflict is used when try to lock an already locked key.
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ErrLockConflict = errors.New("Error: Lock conflict")
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// ErrLazyConditionPairsNotMatch is used when value in store differs from expect pairs.
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ErrLazyConditionPairsNotMatch = errors.New("Error: Lazy condition pairs not match")
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// ErrRetryable is used when KV store occurs RPC error or some other
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// errors which SQL layer can safely retry.
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ErrRetryable = errors.New("Error: KV error safe to retry")
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// ErrCannotSetNilValue is the error when sets an empty value.
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ErrCannotSetNilValue = errors.New("can not set nil value")
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// ErrInvalidTxn is the error when commits or rollbacks in an invalid transaction.
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ErrInvalidTxn = errors.New("invalid transaction")
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)
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var (
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codecEncoder = &encoder{
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codec.EncodeKey,
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codec.DecodeKey,
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}
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defaultEncoder = codecEncoder
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)
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type encoder struct {
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enc func(...interface{}) ([]byte, error)
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dec func([]byte) ([]interface{}, error)
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}
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// EncodeValue encodes values before it is stored to the KV store.
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func EncodeValue(values ...interface{}) ([]byte, error) {
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return defaultEncoder.enc(values...)
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}
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// DecodeValue decodes values after it is fetched from the KV store.
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func DecodeValue(data []byte) ([]interface{}, error) {
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return defaultEncoder.dec(data)
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}
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// NextUntil applies FnKeyCmp to each entry of the iterator until meets some condition.
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// It will stop when fn returns true, or iterator is invalid or occur error
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func NextUntil(it Iterator, fn FnKeyCmp) error {
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var err error
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for it.Valid() && !fn([]byte(it.Key())) {
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err = it.Next()
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if err != nil {
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return errors.Trace(err)
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}
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}
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return nil
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}
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