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Golang Engine.Iterate方法代码示例

本文整理汇总了Golang中github.com/cockroachdb/cockroach/storage/engine.Engine.Iterate方法的典型用法代码示例。如果您正苦于以下问题:Golang Engine.Iterate方法的具体用法?Golang Engine.Iterate怎么用?Golang Engine.Iterate使用的例子?那么恭喜您, 这里精选的方法代码示例或许可以为您提供帮助。您也可以进一步了解该方法所在github.com/cockroachdb/cockroach/storage/engine.Engine的用法示例。


在下文中一共展示了Engine.Iterate方法的7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: copySeqCache

func copySeqCache(e engine.Engine, srcID, dstID roachpb.RangeID, keyMin, keyMax engine.MVCCKey) error {
	var scratch [64]byte
	return e.Iterate(keyMin, keyMax,
		func(kv engine.MVCCKeyValue) (bool, error) {
			// Decode the key into a cmd, skipping on error. Otherwise,
			// write it to the corresponding key in the new cache.
			id, epoch, seq, err := decodeSequenceCacheMVCCKey(kv.Key, scratch[:0])
			if err != nil {
				return false, util.Errorf("could not decode a sequence cache key %s: %s",
					kv.Key, err)
			}
			key := keys.SequenceCacheKey(dstID, id, epoch, seq)
			encKey := engine.MakeMVCCMetadataKey(key)
			// Decode the value, update the checksum and re-encode.
			meta := &engine.MVCCMetadata{}
			if err := proto.Unmarshal(kv.Value, meta); err != nil {
				return false, util.Errorf("could not decode sequence cache value %s [% x]: %s",
					kv.Key, kv.Value, err)
			}
			value := meta.Value()
			value.ClearChecksum()
			value.InitChecksum(key)
			meta.RawBytes = value.RawBytes
			_, _, err = engine.PutProto(e, encKey, meta)
			return false, err
		})
}
开发者ID:billhongs,项目名称:cockroach,代码行数:27,代码来源:sequence_cache.go

示例2: CopyFrom

// CopyFrom copies all the cached results from the originRangeID
// response cache into this one. Note that the cache will not be
// locked while copying is in progress. Failures decoding individual
// cache entries return an error. The copy is done directly using the
// engine instead of interpreting values through MVCC for efficiency.
func (rc *ResponseCache) CopyFrom(e engine.Engine, originRangeID proto.RangeID) error {
	prefix := keys.ResponseCacheKey(originRangeID, nil) // response cache prefix
	start := engine.MVCCEncodeKey(prefix)
	end := engine.MVCCEncodeKey(prefix.PrefixEnd())

	return e.Iterate(start, end, func(kv proto.RawKeyValue) (bool, error) {
		// Decode the key into a cmd, skipping on error. Otherwise,
		// write it to the corresponding key in the new cache.
		cmdID, err := rc.decodeResponseCacheKey(kv.Key)
		if err != nil {
			return false, util.Errorf("could not decode a response cache key %s: %s",
				proto.Key(kv.Key), err)
		}
		key := keys.ResponseCacheKey(rc.rangeID, &cmdID)
		encKey := engine.MVCCEncodeKey(key)
		// Decode the value, update the checksum and re-encode.
		meta := &engine.MVCCMetadata{}
		if err := gogoproto.Unmarshal(kv.Value, meta); err != nil {
			return false, util.Errorf("could not decode response cache value %s [% x]: %s",
				proto.Key(kv.Key), kv.Value, err)
		}
		meta.Value.Checksum = nil
		meta.Value.InitChecksum(key)
		_, _, err = engine.PutProto(e, encKey, meta)
		return false, err
	})
}
开发者ID:mberhault,项目名称:cockroach,代码行数:32,代码来源:response_cache.go

示例3: CopyInto

// CopyInto copies all the cached results from this response cache
// into the destRangeID response cache. Failures decoding individual
// cache entries return an error.
func (rc *ResponseCache) CopyInto(e engine.Engine, destRangeID roachpb.RangeID) error {
	start := engine.MVCCEncodeKey(
		keys.ResponseCacheKey(rc.rangeID, roachpb.KeyMin))
	end := engine.MVCCEncodeKey(
		keys.ResponseCacheKey(rc.rangeID, roachpb.KeyMax))

	return e.Iterate(start, end, func(kv engine.MVCCKeyValue) (bool, error) {
		// Decode the key into a cmd, skipping on error. Otherwise,
		// write it to the corresponding key in the new cache.
		family, err := rc.decodeResponseCacheKey(kv.Key)
		if err != nil {
			return false, util.Errorf("could not decode a response cache key %s: %s",
				roachpb.Key(kv.Key), err)
		}
		key := keys.ResponseCacheKey(destRangeID, family)
		encKey := engine.MVCCEncodeKey(key)
		// Decode the value, update the checksum and re-encode.
		meta := &engine.MVCCMetadata{}
		if err := proto.Unmarshal(kv.Value, meta); err != nil {
			return false, util.Errorf("could not decode response cache value %s [% x]: %s",
				roachpb.Key(kv.Key), kv.Value, err)
		}
		meta.Value.Checksum = nil
		meta.Value.InitChecksum(key)
		_, _, err = engine.PutProto(e, encKey, meta)
		return false, err
	})
}
开发者ID:xujun10110,项目名称:cockroach,代码行数:31,代码来源:response_cache.go

示例4: InternalTruncateLog

// InternalTruncateLog discards a prefix of the raft log.
func (r *Range) InternalTruncateLog(batch engine.Engine, ms *engine.MVCCStats, args *proto.InternalTruncateLogRequest, reply *proto.InternalTruncateLogResponse) {
	// args.Index is the first index to keep.
	term, err := r.Term(args.Index - 1)
	if err != nil {
		reply.SetGoError(err)
		return
	}
	start := keys.RaftLogKey(r.Desc().RaftID, 0)
	end := keys.RaftLogKey(r.Desc().RaftID, args.Index)
	err = batch.Iterate(engine.MVCCEncodeKey(start), engine.MVCCEncodeKey(end),
		func(kv proto.RawKeyValue) (bool, error) {
			err := batch.Clear(kv.Key)
			return false, err
		})
	if err != nil {
		reply.SetGoError(err)
		return
	}
	ts := proto.RaftTruncatedState{
		Index: args.Index - 1,
		Term:  term,
	}
	err = engine.MVCCPutProto(batch, ms, keys.RaftTruncatedStateKey(r.Desc().RaftID),
		proto.ZeroTimestamp, nil, &ts)
	reply.SetGoError(err)
}
开发者ID:simonzhangsm,项目名称:cockroach,代码行数:27,代码来源:range_command.go

示例5: loadRangeDescriptor

func loadRangeDescriptor(
	db engine.Engine, rangeID roachpb.RangeID,
) (roachpb.RangeDescriptor, error) {
	var desc roachpb.RangeDescriptor
	handleKV := func(kv engine.MVCCKeyValue) (bool, error) {
		if kv.Key.Timestamp == hlc.ZeroTimestamp {
			// We only want values, not MVCCMetadata.
			return false, nil
		}
		if err := checkRangeDescriptorKey(kv.Key); err != nil {
			// Range descriptor keys are interleaved with others, so if it
			// doesn't parse as a range descriptor just skip it.
			return false, nil
		}
		if err := getProtoValue(kv.Value, &desc); err != nil {
			return false, err
		}
		return desc.RangeID == rangeID, nil
	}

	// Range descriptors are stored by key, so we have to scan over the
	// range-local data to find the one for this RangeID.
	start := engine.MakeMVCCMetadataKey(keys.LocalRangePrefix)
	end := engine.MakeMVCCMetadataKey(keys.LocalRangeMax)

	if err := db.Iterate(start, end, handleKV); err != nil {
		return roachpb.RangeDescriptor{}, err
	}
	if desc.RangeID == rangeID {
		return desc, nil
	}
	return roachpb.RangeDescriptor{}, fmt.Errorf("range descriptor %d not found", rangeID)
}
开发者ID:YuleiXiao,项目名称:cockroach,代码行数:33,代码来源:debug.go

示例6: CopyFrom

// CopyFrom copies all the cached results from another response cache
// into this one. Note that the cache will not be locked while copying
// is in progress. Failures decoding individual cache entries return an
// error. The copy is done directly using the engine instead of interpreting
// values through MVCC for efficiency.
func (rc *ResponseCache) CopyFrom(e engine.Engine, originRaftID int64) error {
	prefix := engine.ResponseCacheKey(originRaftID, nil) // response cache prefix
	start := engine.MVCCEncodeKey(prefix)
	end := engine.MVCCEncodeKey(prefix.PrefixEnd())

	return e.Iterate(start, end, func(kv proto.RawKeyValue) (bool, error) {
		// Decode the key into a cmd, skipping on error. Otherwise,
		// write it to the corresponding key in the new cache.
		cmdID, err := rc.decodeResponseCacheKey(kv.Key)
		if err != nil {
			return false, util.Errorf("could not decode a response cache key %q: %s", kv.Key, err)
		}
		encKey := engine.MVCCEncodeKey(engine.ResponseCacheKey(rc.raftID, &cmdID))
		return false, rc.engine.Put(encKey, kv.Value)
	})
}
开发者ID:josephwinston,项目名称:cockroach,代码行数:21,代码来源:response_cache.go

示例7: copySeqCache

func copySeqCache(
	e engine.Engine,
	ms *engine.MVCCStats,
	srcID, dstID roachpb.RangeID,
	keyMin, keyMax engine.MVCCKey,
) (int, error) {
	var scratch [64]byte
	var count int
	var meta engine.MVCCMetadata
	// TODO(spencer): look into making this an MVCCIteration and writing
	// the values using MVCC so we can avoid the ugliness of updating
	// the MVCCStats by hand below.
	err := e.Iterate(keyMin, keyMax,
		func(kv engine.MVCCKeyValue) (bool, error) {
			// Decode the key, skipping on error. Otherwise, write it to the
			// corresponding key in the new cache.
			txnID, err := decodeAbortCacheMVCCKey(kv.Key, scratch[:0])
			if err != nil {
				return false, util.Errorf("could not decode an abort cache key %s: %s", kv.Key, err)
			}
			key := keys.AbortCacheKey(dstID, txnID)
			encKey := engine.MakeMVCCMetadataKey(key)
			// Decode the MVCCMetadata value.
			if err := proto.Unmarshal(kv.Value, &meta); err != nil {
				return false, util.Errorf("could not decode mvcc metadata %s [% x]: %s", kv.Key, kv.Value, err)
			}
			value := meta.Value()
			value.ClearChecksum()
			value.InitChecksum(key)
			meta.RawBytes = value.RawBytes

			keyBytes, valBytes, err := engine.PutProto(e, encKey, &meta)
			if err != nil {
				return false, err
			}
			count++
			if ms != nil {
				ms.SysBytes += keyBytes + valBytes
				ms.SysCount++
			}
			return false, nil
		})
	return count, err
}
开发者ID:GitGoldie,项目名称:cockroach,代码行数:44,代码来源:abort_cache.go


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