// getCachedRangeDescriptorLocked is a helper function to retrieve the
// descriptor of the range which contains the given key, if present in the
// cache. It is assumed that the caller holds a read lock on rdc.rangeCacheMu.
func (rdc *rangeDescriptorCache) getCachedRangeDescriptorLocked(key roachpb.Key, inclusive bool) (
rangeCacheKey, *roachpb.RangeDescriptor) {
// The cache is indexed using the end-key of the range, but the
// end-key is non-inclusive by default.
var metaKey roachpb.Key
if !inclusive {
metaKey = keys.RangeMetaKey(key.Next())
} else {
metaKey = keys.RangeMetaKey(key)
}
k, v, ok := rdc.rangeCache.Ceil(rangeCacheKey(metaKey))
if !ok {
return nil, nil
}
metaEndKey := k.(rangeCacheKey)
rd := v.(*roachpb.RangeDescriptor)
// Check that key actually belongs to the range.
if !rd.ContainsKey(key) {
// The key is the EndKey and we're inclusive, so just return the range descriptor.
if inclusive && key.Equal(rd.EndKey) {
return metaEndKey, rd
}
return nil, nil
}
// The key is the StartKey, but we're inclusive and thus need to return the
// previous range descriptor, but it is not in the cache yet.
if inclusive && key.Equal(rd.StartKey) {
return nil, nil
}
return metaEndKey, rd
}
// GetIndex searches the kv list for 'key' and returns its index if found.
func (s SystemConfig) GetIndex(key roachpb.Key) (int, bool) {
l := len(s.Values)
index := sort.Search(l, func(i int) bool {
return bytes.Compare(s.Values[i].Key, key) >= 0
})
if index == l || !key.Equal(s.Values[index].Key) {
return 0, false
}
return index, true
}
// GetIndex searches the kv list for 'key' and returns its index if found.
func (s *SystemConfig) GetIndex(key roachpb.Key) (int, bool) {
if s == nil {
return 0, false
}
l := len(s.Values)
index := sort.Search(l, func(i int) bool {
return !s.Values[i].Key.Less(key)
})
if index == l || !key.Equal(s.Values[index].Key) {
return 0, false
}
return index, true
}
// ObjectIDForKey returns the object ID (table or database) for 'key',
// or (_, false) if not within the structured key space.
func ObjectIDForKey(key roachpb.Key) (uint32, bool) {
if key.Equal(roachpb.KeyMax) {
return 0, false
}
if key.Equal(keys.TableDataPrefix) {
// TODO(marc): this should eventually return SystemDatabaseID.
return 0, false
}
remaining := bytes.TrimPrefix(key, keys.TableDataPrefix)
if len(remaining) == len(key) {
// TrimPrefix returns the input untouched if the prefix doesn't match.
return 0, false
}
// Consume first encoded int.
_, id64, err := encoding.DecodeUvarint(remaining)
return uint32(id64), err == nil
}
// PrettyPrint prints the key in a human readable format:
//
// Key's Format Key's Value
// /Local/... "\x01"+...
// /Store/... "\x01s"+...
// /RangeID/... "\x01s"+[rangeid]
// /[rangeid]/AbortCache/[id] "\x01s"+[rangeid]+"abc-"+[id]
// /[rangeid]/RaftLeaderLease "\x01s"+[rangeid]+"rfll"
// /[rangeid]/RaftTombstone "\x01s"+[rangeid]+"rftb"
// /[rangeid]/RaftHardState "\x01s"+[rangeid]+"rfth"
// /[rangeid]/RaftAppliedIndex "\x01s"+[rangeid]+"rfta"
// /[rangeid]/RaftLog/logIndex:[logIndex] "\x01s"+[rangeid]+"rftl"+[logIndex]
// /[rangeid]/RaftTruncatedState "\x01s"+[rangeid]+"rftt"
// /[rangeid]/RaftLastIndex "\x01s"+[rangeid]+"rfti"
// /[rangeid]/RangeLastReplicaGCTimestamp "\x01s"+[rangeid]+"rlrt"
// /[rangeid]/RangeLastVerificationTimestamp "\x01s"+[rangeid]+"rlvt"
// /[rangeid]/RangeStats "\x01s"+[rangeid]+"stat"
// /Range/... "\x01k"+...
// /RangeDescriptor/[key] "\x01k"+[key]+"rdsc"
// /RangeTreeNode/[key] "\x01k"+[key]+"rtn-"
// /Transaction/addrKey:[key]/id:[id] "\x01k"+[key]+"txn-"+[id]
// /Local/Max "\x02"
//
// /Meta1/[key] "\x02"+[key]
// /Meta2/[key] "\x03"+[key]
// /System/... "\x04"
// /StatusNode/[key] "\x04status-node-"+[key]
// /System/Max "\x05"
//
// /Table/[key] [key]
//
// /Min ""
// /Max "\xff\xff"
func PrettyPrint(key roachpb.Key) string {
for _, k := range constKeyDict {
if key.Equal(k.value) {
return k.name
}
}
for _, k := range keyOfKeyDict {
if bytes.HasPrefix(key, k.prefix) {
key = key[len(k.prefix):]
str, formatted := prettyPrintInternal(key)
if formatted {
return k.name + str
}
return k.name + "/" + str
}
}
str, _ := prettyPrintInternal(key)
return str
}
// validateRangeMetaKey validates that the given key is a valid Range Metadata
// key. This checks only the constraints common to forward and backwards scans:
// correct prefix and not exceeding KeyMax.
func validateRangeMetaKey(key roachpb.Key) error {
// KeyMin is a valid key.
if key.Equal(roachpb.KeyMin) {
return nil
}
// Key must be at least as long as Meta1Prefix.
if len(key) < len(Meta1Prefix) {
return NewInvalidRangeMetaKeyError("too short", key)
}
prefix, body := roachpb.Key(key[:len(Meta1Prefix)]), roachpb.Key(key[len(Meta1Prefix):])
if !prefix.Equal(Meta2Prefix) && !prefix.Equal(Meta1Prefix) {
return NewInvalidRangeMetaKeyError("not a meta key", key)
}
if roachpb.KeyMax.Less(body) {
return NewInvalidRangeMetaKeyError("body of meta key range lookup is > KeyMax", key)
}
return nil
}
// MetaScanBounds returns the range [start,end) within which the desired meta
// record can be found by means of an engine scan. The given key must be a
// valid RangeMetaKey as defined by validateRangeMetaKey.
func MetaScanBounds(key roachpb.Key) (roachpb.Key, roachpb.Key, error) {
if err := validateRangeMetaKey(key); err != nil {
return nil, nil, err
}
if key.Equal(Meta2KeyMax) {
return nil, nil, NewInvalidRangeMetaKeyError("Meta2KeyMax can't be used as the key of scan", key)
}
if key.Equal(roachpb.KeyMin) {
// Special case KeyMin: find the first entry in meta1.
return Meta1Prefix, Meta1Prefix.PrefixEnd(), nil
}
if key.Equal(Meta1KeyMax) {
// Special case Meta1KeyMax: this is the last key in Meta1, we don't want
// to start at Next().
return key, Meta1Prefix.PrefixEnd(), nil
}
// Otherwise find the first entry greater than the given key in the same meta prefix.
return key.Next(), roachpb.Key(key[:len(Meta1Prefix)]).PrefixEnd(), nil
}
// MetaReverseScanBounds returns the range [start,end) within which the desired
// meta record can be found by means of a reverse engine scan. The given key
// must be a valid RangeMetaKey as defined by validateRangeMetaKey.
func MetaReverseScanBounds(key roachpb.Key) (roachpb.Key, roachpb.Key, error) {
if err := validateRangeMetaKey(key); err != nil {
return nil, nil, err
}
if key.Equal(roachpb.KeyMin) || key.Equal(Meta1Prefix) {
return nil, nil, NewInvalidRangeMetaKeyError("KeyMin and Meta1Prefix can't be used as the key of reverse scan", key)
}
if key.Equal(Meta2Prefix) {
// Special case Meta2Prefix: this is the first key in Meta2, and the scan
// interval covers all of Meta1.
return Meta1Prefix, key.Next(), nil
}
// Otherwise find the first entry greater than the given key and find the last entry
// in the same prefix. For MVCCReverseScan the endKey is exclusive, if we want to find
// the range descriptor the given key specified,we need to set the key.Next() as the
// MVCCReverseScan`s endKey. For example:
// If we have ranges [a,f) and [f,z), then we'll have corresponding meta records
// at f and z. If you're looking for the meta record for key f, then you want the
// second record (exclusive in MVCCReverseScan), hence key.Next() below.
return key[:len(Meta1Prefix)], key.Next(), nil
}
