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类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
})
}
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
})
}
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
})
}
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)
}
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)
}
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)
})
}
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
}