// prev gives the right boundary of the union of all requests which don't
// affect keys larger than the given key.
// TODO(tschottdorf): again, better on BatchRequest itself, but can't pull
// 'keys' into 'proto'.
func prev(ba proto.BatchRequest, k proto.Key) proto.Key {
candidate := proto.KeyMin
for _, union := range ba.Requests {
h := union.GetValue().(proto.Request).Header()
addr := keys.KeyAddress(h.Key)
eAddr := keys.KeyAddress(h.EndKey)
if len(eAddr) == 0 {
// Can probably avoid having to compute Next() here if
// we're in the mood for some more complexity.
eAddr = addr.Next()
}
if !eAddr.Less(k) {
if !k.Less(addr) {
// Range contains k, so won't be able to go lower.
return k
}
// Range is disjoint from [KeyMin,k).
continue
}
// We want the largest surviving candidate.
if candidate.Less(addr) {
candidate = addr
}
}
return candidate
}
// Add the specified timestamp to the cache as covering the range of
// keys from start to end. If end is nil, the range covers the start
// key only. txnID is nil for no transaction. readOnly specifies
// whether the command adding this timestamp was read-only or not.
func (tc *TimestampCache) Add(start, end proto.Key, timestamp proto.Timestamp, txnID []byte, readOnly bool) {
// This gives us a memory-efficient end key if end is empty.
if len(end) == 0 {
end = start.Next()
start = end[:len(start)]
}
if tc.latest.Less(timestamp) {
tc.latest = timestamp
}
// Only add to the cache if the timestamp is more recent than the
// low water mark.
if tc.lowWater.Less(timestamp) {
// Check existing, overlapping entries. Remove superseded
// entries or return without adding this entry if necessary.
key := tc.cache.NewKey(start, end)
for _, o := range tc.cache.GetOverlaps(start, end) {
ce := o.Value.(cacheEntry)
if ce.readOnly != readOnly {
continue
}
if o.Key.Contains(key) && !ce.timestamp.Less(timestamp) {
return // don't add this key; there's already a cache entry with >= timestamp.
} else if key.Contains(o.Key) && !timestamp.Less(ce.timestamp) {
tc.cache.Del(o.Key) // delete existing key; this cache entry supersedes.
}
}
ce := cacheEntry{timestamp: timestamp, txnID: txnID, readOnly: readOnly}
tc.cache.Add(key, ce)
}
}
// clearOverlappingCachedRangeDescriptors looks up and clears any
// cache entries which overlap the specified key or descriptor.
func (rdc *rangeDescriptorCache) clearOverlappingCachedRangeDescriptors(key, metaKey proto.Key, desc *proto.RangeDescriptor) {
if desc.StartKey.Equal(desc.EndKey) { // True for some unittests.
return
}
// Clear out any descriptors which subsume the key which we're going
// to cache. For example, if an existing KeyMin->KeyMax descriptor
// should be cleared out in favor of a KeyMin->"m" descriptor.
k, v, ok := rdc.rangeCache.Ceil(rangeCacheKey(metaKey))
if ok {
descriptor := v.(*proto.RangeDescriptor)
if !key.Less(descriptor.StartKey) && !descriptor.EndKey.Less(key) {
if log.V(1) {
log.Infof("clearing overlapping descriptor: key=%s desc=%s", k, descriptor)
}
rdc.rangeCache.Del(k.(rangeCacheKey))
}
}
// Also clear any descriptors which are subsumed by the one we're
// going to cache. This could happen on a merge (and also happens
// when there's a lot of concurrency). Iterate from the range meta key
// after RangeMetaKey(desc.StartKey) to the range meta key for desc.EndKey.
rdc.rangeCache.DoRange(func(k, v interface{}) {
if log.V(1) {
log.Infof("clearing subsumed descriptor: key=%s desc=%s", k, v.(*proto.RangeDescriptor))
}
rdc.rangeCache.Del(k.(rangeCacheKey))
}, rangeCacheKey(keys.RangeMetaKey(desc.StartKey).Next()),
rangeCacheKey(keys.RangeMetaKey(desc.EndKey)))
}
// getConfig retrieves the configuration for the specified key. If the
// key is empty, all configurations are returned. Otherwise, the
// leading "/" path delimiter is stripped and the configuration
// matching the remainder is retrieved. Note that this will retrieve
// the default config if "key" is equal to "/", and will list all
// configs if "key" is equal to "". The body result contains a listing
// of keys and retrieval of a config. The output format is determined
// by the request header.
func getConfig(db *client.DB, configPrefix proto.Key, config gogoproto.Message,
path string, r *http.Request) (body []byte, contentType string, err error) {
// Scan all configs if the key is empty.
if len(path) == 0 {
var rows []client.KeyValue
if rows, err = db.Scan(configPrefix, configPrefix.PrefixEnd(), maxGetResults); err != nil {
return
}
if len(rows) == maxGetResults {
log.Warningf("retrieved maximum number of results (%d); some may be missing", maxGetResults)
}
var prefixes []string
for _, row := range rows {
trimmed := bytes.TrimPrefix(row.Key, configPrefix)
prefixes = append(prefixes, url.QueryEscape(string(trimmed)))
}
// Encode the response.
body, contentType, err = util.MarshalResponse(r, prefixes, util.AllEncodings)
} else {
configkey := keys.MakeKey(configPrefix, proto.Key(path[1:]))
if err = db.GetProto(configkey, config); err != nil {
return
}
body, contentType, err = util.MarshalResponse(r, config, util.AllEncodings)
}
return
}
// getDescriptors looks up the range descriptor to use for a query over the
// key range [from,to), with the given lookupOptions. The range descriptor
// which contains the range in which the request should start its query is
// returned first; the returned bool is true in case the given range reaches
// outside the first descriptor.
// In case either of the descriptors is discovered stale, the returned closure
// should be called; it evicts the cache appropriately.
// Note that `from` and `to` are not necessarily Key and EndKey from a
// RequestHeader; it's assumed that they've been translated to key addresses
// already (via KeyAddress).
func (ds *DistSender) getDescriptors(from, to proto.Key, options lookupOptions) (*proto.RangeDescriptor, bool, func(), error) {
var desc *proto.RangeDescriptor
var err error
var descKey proto.Key
if !options.useReverseScan {
descKey = from
} else {
descKey = to
}
desc, err = ds.rangeCache.LookupRangeDescriptor(descKey, options)
if err != nil {
return nil, false, nil, err
}
// Checks whether need to get next range descriptor. If so, returns true.
needAnother := func(desc *proto.RangeDescriptor, isReverse bool) bool {
if isReverse {
return from.Less(desc.StartKey)
}
return desc.EndKey.Less(to)
}
evict := func() {
ds.rangeCache.EvictCachedRangeDescriptor(descKey, desc, options.useReverseScan)
}
return desc, needAnother(desc, options.useReverseScan), evict, nil
}
// ValidateRangeMetaKey validates that the given key is a valid Range Metadata
// key.
func ValidateRangeMetaKey(key proto.Key) error {
// KeyMin is a valid key.
if key.Equal(proto.KeyMin) {
return nil
}
// Key must be at least as long as Meta1Prefix.
if len(key) < len(Meta1Prefix) {
return NewInvalidRangeMetaKeyError("too short", key)
}
prefix, body := proto.Key(key[:len(Meta1Prefix)]), proto.Key(key[len(Meta1Prefix):])
if prefix.Equal(Meta2Prefix) {
if body.Less(proto.KeyMax) {
return nil
}
return NewInvalidRangeMetaKeyError("body of meta2 range lookup is >= KeyMax", key)
}
if prefix.Equal(Meta1Prefix) {
if proto.KeyMax.Less(body) {
return NewInvalidRangeMetaKeyError("body of meta1 range lookup is > KeyMax", key)
}
return nil
}
return NewInvalidRangeMetaKeyError("not a meta key", key)
}
// writeDescriptor takes a Table or Database descriptor and writes it
// if needed, incrementing the descriptor counter.
func (p *planner) writeDescriptor(key proto.Key, descriptor descriptorProto, ifNotExists bool) error {
// Check whether key exists.
gr, err := p.db.Get(key)
if err != nil {
return err
}
if gr.Exists() {
if ifNotExists {
// Noop.
return nil
}
// Key exists, but we don't want it to: error out.
// TODO(marc): prettify the error (strip stuff off the type name)
return fmt.Errorf("%T \"%s\" already exists", descriptor, key.String())
}
// Increment unique descriptor counter.
if ir, err := p.db.Inc(keys.DescIDGenerator, 1); err == nil {
descriptor.SetID(uint32(ir.ValueInt() - 1))
} else {
return err
}
// TODO(pmattis): The error currently returned below is likely going to be
// difficult to interpret.
// TODO(pmattis): Need to handle if-not-exists here as well.
descKey := keys.MakeDescMetadataKey(descriptor.GetID())
return p.db.Txn(func(txn *client.Txn) error {
b := &client.Batch{}
b.CPut(key, descKey, nil)
b.CPut(descKey, descriptor, nil)
return txn.Commit(b)
})
}
// Add adds a command to the queue which affects the specified key
// range. If end is empty, it is set to start.Next(), meaning the
// command affects a single key. The returned interface is the key for
// the command queue and must be re-supplied on subsequent invocation
// of Remove().
//
// Add should be invoked after waiting on already-executing,
// overlapping commands via the WaitGroup initialized through
// GetWait().
func (cq *CommandQueue) Add(start, end proto.Key, readOnly bool) interface{} {
if len(end) == 0 {
end = start.Next()
}
key := cq.cache.NewKey(start, end)
cq.cache.Add(key, &cmd{readOnly: readOnly})
return key
}
// Get searches the kv list for 'key' and returns its
// raw byte value if found. ok is true only if the key is found.
func (s *SystemConfig) Get(key proto.Key) ([]byte, 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 nil, false
}
// TODO(marc): I'm pretty sure a Value returned by MVCCScan can
// never be nil. Should check.
return s.Values[index].Value.Bytes, true
}
// ComputeSplitKeys takes a start and end key and returns an array of keys
// at which to split the span [start, end).
// The only required splits are at each user table prefix.
func (s *SystemConfig) ComputeSplitKeys(startKey, endKey proto.Key) []proto.Key {
if TestingDisableTableSplits {
return nil
}
tableStart := proto.Key(keys.UserTableDataMin)
if !tableStart.Less(endKey) {
// This range is before the user tables span: no required splits.
return nil
}
startID, ok := ObjectIDForKey(startKey)
if !ok || startID <= keys.MaxReservedDescID {
// The start key is either:
// - not part of the structured data span
// - part of the system span
// In either case, start looking for splits at the first ID usable
// by the user data span.
startID = keys.MaxReservedDescID + 1
} else {
// The start key is either already a split key, or after the split
// key for its ID. We can skip straight to the next one.
startID++
}
// Find the largest object ID.
// We can't keep splitting until we reach endKey as it could be proto.KeyMax.
endID, err := s.GetLargestObjectID()
if err != nil {
log.Errorf("unable to determine largest object ID from system config: %s", err)
return nil
}
// Build key prefixes for sequential table IDs until we reach endKey.
var splitKeys proto.KeySlice
var key proto.Key
// endID could be smaller than startID if we don't have user tables.
for id := startID; id <= endID; id++ {
key = keys.MakeTablePrefix(id)
// Skip if the range starts on a split key.
if !startKey.Less(key) {
continue
}
// Handle the case where EndKey is already a table prefix.
if !key.Less(endKey) {
break
}
splitKeys = append(splitKeys, key)
}
return splitKeys
}
// GetIndex searches the kv list for 'key' and returns its index if found.
func (s *SystemConfig) GetIndex(key proto.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
}
// GetWait initializes the supplied wait group with the number of
// executing commands which overlap the specified key range. If end is
// empty, end is set to start.Next(), meaning the command affects a
// single key. The caller should call wg.Wait() to wait for
// confirmation that all gating commands have completed or
// failed. readOnly is true if the requester is a read-only command;
// false for read-write.
func (cq *CommandQueue) GetWait(start, end proto.Key, readOnly bool, wg *sync.WaitGroup) {
// This gives us a memory-efficient end key if end is empty.
if len(end) == 0 {
end = start.Next()
start = end[:len(start)]
}
for _, c := range cq.cache.GetOverlaps(start, end) {
c := c.Value.(*cmd)
// Only add to the wait group if one of the commands isn't read-only.
if !readOnly || !c.readOnly {
c.pending = append(c.pending, wg)
wg.Add(1)
}
}
}
// verifyBinarySearchTree checks to ensure that all keys to the left of the root
// node are less than it, and all nodes to the right of the root node are
// greater than it. It recursively walks the tree to perform this same check.
func verifyBinarySearchTree(t *testing.T, nodes map[string]proto.RangeTreeNode, testName string, node *proto.RangeTreeNode, keyMin, keyMax proto.Key) {
if node == nil {
return
}
if !node.Key.Less(keyMax) {
t.Errorf("%s: Failed Property BST - The key %s is not less than %s.", testName, node.Key, keyMax)
}
// We need the extra check since proto.KeyMin is actually a range start key.
if !keyMin.Less(node.Key) && !node.Key.Equal(proto.KeyMin) {
t.Errorf("%s: Failed Property BST - The key %s is not greater than %s.", testName, node.Key, keyMin)
}
left, right := getLeftAndRight(t, nodes, testName, node)
verifyBinarySearchTree(t, nodes, testName, left, keyMin, node.Key)
verifyBinarySearchTree(t, nodes, testName, right, node.Key, keyMax)
}
// getDescriptor looks up the descriptor at `key`, validates it,
// and unmarshals it into `descriptor`.
func (p *planner) getDescriptor(key proto.Key, descriptor descriptorProto) error {
gr, err := p.db.Get(key)
if err != nil {
return err
}
if !gr.Exists() {
// TODO(marc): prettify the error (strip stuff off the type name)
return fmt.Errorf("%T \"%s\" does not exist", descriptor, key.String())
}
descKey := gr.ValueBytes()
if err := p.db.GetProto(descKey, descriptor); err != nil {
return err
}
return descriptor.Validate()
}
// ObjectIDForKey returns the object ID (table or database) for 'key',
// or (_, false) if not within the structured key space.
func ObjectIDForKey(key proto.Key) (uint32, bool) {
if key.Equal(proto.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
}
// GetMax returns the maximum read and write timestamps which overlap
// the interval spanning from start to end. Cached timestamps matching
// the specified txnID are not considered. If no part of the specified
// range is overlapped by timestamps in the cache, the low water
// timestamp is returned for both read and write timestamps.
//
// The txn ID prevents restarts with a pattern like: read("a"),
// write("a"). The read adds a timestamp for "a". Then the write (for
// the same transaction) would get that as the max timestamp and be
// forced to increment it. This allows timestamps from the same txn
// to be ignored.
func (tc *TimestampCache) GetMax(start, end proto.Key, txnID []byte) (proto.Timestamp, proto.Timestamp) {
if len(end) == 0 {
end = start.Next()
}
maxR := tc.lowWater
maxW := tc.lowWater
for _, o := range tc.cache.GetOverlaps(start, end) {
ce := o.Value.(cacheEntry)
if ce.txnID == nil || txnID == nil || !proto.TxnIDEqual(txnID, ce.txnID) {
if ce.readOnly && maxR.Less(ce.timestamp) {
maxR = ce.timestamp
} else if !ce.readOnly && maxW.Less(ce.timestamp) {
maxW = ce.timestamp
}
}
}
return maxR, maxW
}
// 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 proto.Key) (proto.Key, proto.Key, error) {
if key.Equal(proto.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 ["", "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
}
// 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 proto.Key) (
rangeCacheKey, *proto.RangeDescriptor) {
// The cache is indexed using the end-key of the range, but the
// end-key is non-inclusive. If inclusive is false, we access the
// cache using key.Next().
metaKey := keys.RangeMetaKey(key.Next())
k, v, ok := rdc.rangeCache.Ceil(rangeCacheKey(metaKey))
if !ok {
return nil, nil
}
metaEndKey := k.(rangeCacheKey)
rd := v.(*proto.RangeDescriptor)
// Check that key actually belongs to range
if !rd.ContainsKey(keys.KeyAddress(key)) {
return nil, nil
}
return metaEndKey, rd
}
// next gives the left boundary of the union of all requests which don't
// affect keys less than the given key.
// TODO(tschottdorf): again, better on BatchRequest itself, but can't pull
// 'keys' into 'proto'.
func next(ba proto.BatchRequest, k proto.Key) proto.Key {
candidate := proto.KeyMax
for _, union := range ba.Requests {
h := union.GetValue().(proto.Request).Header()
addr := keys.KeyAddress(h.Key)
if addr.Less(k) {
if eAddr := keys.KeyAddress(h.EndKey); k.Less(eAddr) {
// Starts below k, but continues beyond. Need to stay at k.
return k
}
// Affects only [KeyMin,k).
continue
}
// We want the smallest of the surviving candidates.
if addr.Less(candidate) {
candidate = addr
}
}
return candidate
}
func (db *testDescriptorDB) getDescriptor(key proto.Key) []proto.RangeDescriptor {
response := make([]proto.RangeDescriptor, 0, 3)
for i := 0; i < 3; i++ {
v := db.data.Ceil(testDescriptorNode{
&proto.RangeDescriptor{
EndKey: key.Next(),
},
})
if v == nil {
break
}
response = append(response, *(v.(testDescriptorNode).RangeDescriptor))
// Break to keep from skidding off the end of the available ranges.
if response[i].EndKey.Equal(proto.KeyMax) {
break
}
key = proto.Key(response[i].EndKey).Next()
}
return response
}
// loadConfigMap scans the config entries under keyPrefix and
// instantiates/returns a config map and its sha256 hash. Prefix
// configuration maps include accounting, permissions, and zones.
func loadConfigMap(eng engine.Engine, keyPrefix proto.Key, configI interface{}) (PrefixConfigMap, []byte, error) {
// TODO(tschottdorf): Currently this does not handle intents well.
kvs, _, err := engine.MVCCScan(eng, keyPrefix, keyPrefix.PrefixEnd(), 0, proto.MaxTimestamp, true /* consistent */, nil)
if err != nil {
return nil, nil, err
}
var configs []*PrefixConfig
sha := sha256.New()
for _, kv := range kvs {
// Instantiate an instance of the config type by unmarshalling
// proto encoded config from the Value into a new instance of configI.
config := reflect.New(reflect.TypeOf(configI)).Interface().(gogoproto.Message)
if err := gogoproto.Unmarshal(kv.Value.Bytes, config); err != nil {
return nil, nil, util.Errorf("unable to unmarshal config key %s: %s", string(kv.Key), err)
}
configs = append(configs, &PrefixConfig{Prefix: bytes.TrimPrefix(kv.Key, keyPrefix), Config: config})
sha.Write(kv.Value.Bytes)
}
m, err := NewPrefixConfigMap(configs)
return m, sha.Sum(nil), err
}
// 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 proto.Key, inclusive bool) (
rangeCacheKey, *proto.RangeDescriptor) {
// The cache is indexed using the end-key of the range, but the
// end-key is non-inclusive by default.
var metaKey proto.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.(*proto.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
}
// addKeyRange adds the specified key range to the interval cache,
// taking care not to add this range if existing entries already
// completely cover the range.
func (tm *txnMetadata) addKeyRange(start, end proto.Key) {
// This gives us a memory-efficient end key if end is empty.
// The most common case for keys in the intents interval map
// is for single keys. However, the interval cache requires
// a non-empty interval, so we create two key slices which
// share the same underlying byte array.
if len(end) == 0 {
end = start.Next()
start = end[:len(start)]
}
key := tm.keys.NewKey(start, end)
for _, o := range tm.keys.GetOverlaps(start, end) {
if o.Key.Contains(key) {
return
} else if key.Contains(o.Key) {
tm.keys.Del(o.Key)
}
}
// Since no existing key range fully covered this range, add it now.
tm.keys.Add(key, nil)
}
// MatchByPrefix returns the longest matching PrefixConfig. If the key
// specified does not match an existing prefix, a panic will
// result. Based on the comments in NewPrefixConfigMap, that example
// will have a final list of PrefixConfig entries which look like:
//
// "/": config1
// "/db1": config2
// "/db1/table": config3
// "/db1/tablf": config2
// "/db2": config1
// "/db3": config4
// "/db4": config1
//
// To find the longest matching prefix, we take the lower bound of the
// specified key.
func (p PrefixConfigMap) MatchByPrefix(key proto.Key) *PrefixConfig {
n := sort.Search(len(p), func(i int) bool {
return key.Compare(p[i].Prefix) < 0
})
if n == 0 || n > len(p) {
panic("should never match a key outside of default range")
}
// If the matched prefix config is already canonical, return it immediately.
pc := p[n-1]
if pc.Canonical == nil {
return pc
}
// Otherwise, search for the canonical prefix config.
n = sort.Search(len(p), func(i int) bool {
return pc.Canonical.Compare(p[i].Prefix) <= 0
})
// Should find an exact match every time.
if n >= len(p) || !pc.Canonical.Equal(p[n].Prefix) {
panic(fmt.Sprintf("canonical lookup for key %q failed", string(pc.Canonical)))
}
return p[n]
}
// insert performs the insertion of a new range into the RangeTree. It will
// recursively call insert until it finds the correct location. It will not
// overwrite an already existing key, but that case should not occur.
func (tc *treeContext) insert(node *proto.RangeTreeNode, key proto.Key) (*proto.RangeTreeNode, error) {
if node == nil {
// Insert the new node here.
node = &proto.RangeTreeNode{
Key: key,
}
tc.setNode(node)
} else if key.Less(node.Key) {
// Walk down the tree to the left.
left, err := tc.getNode(node.LeftKey)
if err != nil {
return nil, err
}
left, err = tc.insert(left, key)
if err != nil {
return nil, err
}
if node.LeftKey == nil || !(*node.LeftKey).Equal(left.Key) {
node.LeftKey = &left.Key
tc.setNode(node)
}
} else {
// Walk down the tree to the right.
right, err := tc.getNode(node.RightKey)
if err != nil {
return nil, err
}
right, err = tc.insert(right, key)
if err != nil {
return nil, err
}
if node.RightKey == nil || !(*node.RightKey).Equal(right.Key) {
node.RightKey = &right.Key
tc.setNode(node)
}
}
return tc.walkUpRot23(node)
}
// ObjectIDForKey returns the object ID (table or database) for 'key',
// or (_, false) if not within the structured key space.
func ObjectIDForKey(key proto.Key) (uint32, bool) {
if key.Equal(proto.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.
defer func() {
// Nothing to do, default return values mean "could not decode", which is
// definitely the case if DecodeUvarint panics.
_ = recover()
}()
_, id64 := encoding.DecodeUvarint(remaining)
return uint32(id64), true
}
// verifyBinarySearchTree checks to ensure that all keys to the left of the root
// node are less than it, and all nodes to the right of the root node are
// greater than it. It recursively walks the tree to perform this same check.
func verifyBinarySearchTree(t *testing.T, tc *treeContext, testName string, node *proto.RangeTreeNode, keyMin, keyMax proto.Key) {
if !node.Key.Less(keyMax) {
t.Errorf("%s: Failed Property BST - The key %s is not less than %s.", testName, node.Key, keyMax)
}
if !keyMin.Less(node.Key) {
t.Errorf("%s: Failed Property BST - The key %s is not greater than %s.", testName, node.Key, keyMin)
}
if node.LeftKey != nil {
left, err := tc.getNode(node.LeftKey)
if err != nil {
t.Fatal(err)
}
verifyBinarySearchTree(t, tc, testName, left, keyMin, node.Key)
}
if node.RightKey != nil {
right, err := tc.getNode(node.RightKey)
if err != nil {
t.Fatal(err)
}
verifyBinarySearchTree(t, tc, testName, right, node.Key, keyMax)
}
}
// MetaScanBounds returns the start and end keys of the range 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 proto.Key) (proto.Key, proto.Key) {
if key.Equal(proto.KeyMin) {
// Special case KeyMin: find the first entry in meta1.
return Meta1Prefix, Meta1Prefix.PrefixEnd()
}
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()
}
// Otherwise find the first entry greater than the given key in the same meta prefix.
return key.Next(), proto.Key(key[:len(Meta1Prefix)]).PrefixEnd()
}
// 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 proto.Key) (proto.Key, proto.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(proto.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(), proto.Key(key[:len(Meta1Prefix)]).PrefixEnd(), nil
}
// VisitPrefixes invokes the visitor function for each prefix overlapped
// by the specified key range [start, end). If visitor returns done=true
// or an error, the visitation is halted.
func (p PrefixConfigMap) VisitPrefixes(start, end proto.Key,
visitor func(start, end proto.Key, config gogoproto.Message) (bool, error)) error {
comp := start.Compare(end)
if comp > 0 {
return util.Errorf("start key %q not less than or equal to end key %q", start, end)
}
startIdx := sort.Search(len(p), func(i int) bool {
return start.Compare(p[i].Prefix) < 0
})
// Common case of start == end.
endIdx := startIdx
if comp != 0 {
endIdx = sort.Search(len(p), func(i int) bool {
return end.Compare(p[i].Prefix) < 0
})
}
if startIdx > len(p) || endIdx > len(p) {
return util.Errorf("start and/or end keys (%q, %q) fall outside prefix range; "+
"startIdx: %d, endIdx: %d, len(p): %d", start, end, startIdx, endIdx, len(p))
}
if startIdx == endIdx {
_, err := visitor(start, end, p[startIdx-1].Config)
return err
}
for i := startIdx; i < endIdx; i++ {
done, err := visitor(start, p[i].Prefix, p[i-1].Config)
if done || err != nil {
return err
}
if p[i].Prefix.Equal(end) {
return nil
}
start = p[i].Prefix
}
done, err := visitor(start, end, p[endIdx-1].Config)
if done || err != nil {
return err
}
return nil
}