本文整理汇总了Golang中github.com/cockroachdb/cockroach/keys.SequenceCacheKeyPrefix函数的典型用法代码示例。如果您正苦于以下问题:Golang SequenceCacheKeyPrefix函数的具体用法?Golang SequenceCacheKeyPrefix怎么用?Golang SequenceCacheKeyPrefix使用的例子?那么恭喜您, 这里精选的函数代码示例或许可以为您提供帮助。
在下文中一共展示了SequenceCacheKeyPrefix函数的3个代码示例,这些例子默认根据受欢迎程度排序。您可以为喜欢或者感觉有用的代码点赞,您的评价将有助于系统推荐出更棒的Golang代码示例。
示例1: Get
// Get looks up the latest sequence number recorded for this transaction ID.
// The latest entry is that with the highest epoch (and then, highest
// sequence). On a miss, zero is returned for both. If an entry is found and a
// SequenceCacheEntry is provided, it is populated from the found value.
func (sc *SequenceCache) Get(e engine.Engine, id []byte, dest *roachpb.SequenceCacheEntry) (uint32, uint32, error) {
if len(id) == 0 {
return 0, 0, errEmptyTxnID
}
// Pull response from disk and read into reply if available. Sequence
// number sorts in decreasing order, so this gives us the largest entry or
// an entry which isn't ours. To avoid encoding an end key for the scan,
// we just scan and check via a simple prefix check whether we read a
// key for "our" cache id.
prefix := keys.SequenceCacheKeyPrefix(sc.rangeID, id)
kvs, _, err := engine.MVCCScan(e, prefix, sc.max, 1, /* num */
roachpb.ZeroTimestamp, true /* consistent */, nil /* txn */)
if err != nil || len(kvs) == 0 || !bytes.HasPrefix(kvs[0].Key, prefix) {
return 0, 0, err
}
_, epoch, seq, err := decodeSequenceCacheKey(kvs[0].Key, sc.scratchBuf[:0])
if err != nil {
return 0, 0, err
}
if dest != nil {
dest.Reset()
// Caller wants to have the unmarshaled value.
if err := kvs[0].Value.GetProto(dest); err != nil {
return 0, 0, err
}
}
return epoch, seq, nil
}
示例2: GetAllTransactionID
// GetAllTransactionID returns all the key-value pairs for the given transaction ID from
// the engine.
func (sc *SequenceCache) GetAllTransactionID(e engine.Engine, id []byte) ([]roachpb.KeyValue, error) {
prefix := keys.SequenceCacheKeyPrefix(sc.rangeID, id)
kvs, _, err := engine.MVCCScan(e, prefix, prefix.PrefixEnd(), 0, /* max */
roachpb.ZeroTimestamp, true /* consistent */, nil /* txn */)
return kvs, err
}
示例3: Del
// Del removes all sequence cache entries for the given transaction.
func (sc *SequenceCache) Del(e engine.Engine, ms *engine.MVCCStats, txnID *uuid.UUID) error {
startKey := keys.SequenceCacheKeyPrefix(sc.rangeID, txnID)
_, err := engine.MVCCDeleteRange(e, ms, startKey, startKey.PrefixEnd(), 0 /* max */, roachpb.ZeroTimestamp, nil /* txn */, false /*returnKeys*/)
return err
}