func applyRange(txnID int64, kv dstorage.KV, r *pb.RangeRequest) (*pb.RangeResponse, error) {
resp := &pb.RangeResponse{}
resp.Header = &pb.ResponseHeader{}
var (
kvs []storagepb.KeyValue
rev int64
err error
)
if txnID != noTxn {
kvs, rev, err = kv.TxnRange(txnID, r.Key, r.RangeEnd, r.Limit, 0)
if err != nil {
return nil, err
}
} else {
kvs, rev, err = kv.Range(r.Key, r.RangeEnd, r.Limit, 0)
if err != nil {
return nil, err
}
}
resp.Header.Revision = rev
for i := range kvs {
resp.Kvs = append(resp.Kvs, &kvs[i])
}
return resp, nil
}
func applyRange(txnID int64, kv dstorage.KV, r *pb.RangeRequest) (*pb.RangeResponse, error) {
resp := &pb.RangeResponse{}
resp.Header = &pb.ResponseHeader{}
var (
kvs []storagepb.KeyValue
rev int64
err error
)
limit := r.Limit
if r.SortOrder != pb.RangeRequest_NONE {
// fetch everything; sort and truncate afterwards
limit = 0
}
if txnID != noTxn {
kvs, rev, err = kv.TxnRange(txnID, r.Key, r.RangeEnd, limit, 0)
if err != nil {
return nil, err
}
} else {
kvs, rev, err = kv.Range(r.Key, r.RangeEnd, limit, 0)
if err != nil {
return nil, err
}
}
if r.SortOrder != pb.RangeRequest_NONE {
var sorter sort.Interface
switch {
case r.SortTarget == pb.RangeRequest_KEY:
sorter = &kvSortByKey{&kvSort{kvs}}
case r.SortTarget == pb.RangeRequest_VERSION:
sorter = &kvSortByVersion{&kvSort{kvs}}
case r.SortTarget == pb.RangeRequest_CREATE:
sorter = &kvSortByCreate{&kvSort{kvs}}
case r.SortTarget == pb.RangeRequest_MOD:
sorter = &kvSortByMod{&kvSort{kvs}}
case r.SortTarget == pb.RangeRequest_VALUE:
sorter = &kvSortByValue{&kvSort{kvs}}
}
switch {
case r.SortOrder == pb.RangeRequest_ASCEND:
sort.Sort(sorter)
case r.SortOrder == pb.RangeRequest_DESCEND:
sort.Sort(sort.Reverse(sorter))
}
if r.Limit > 0 && len(kvs) > int(r.Limit) {
kvs = kvs[:r.Limit]
}
}
resp.Header.Revision = rev
for i := range kvs {
resp.Kvs = append(resp.Kvs, &kvs[i])
}
return resp, nil
}
// applyCompare applies the compare request.
// applyCompare should only be called within a txn request and an valid txn ID must
// be presented. Or applyCompare panics.
// It returns the revision at which the comparison happens. If the comparison
// succeeds, the it returns true. Otherwise it returns false.
func applyCompare(txnID int64, kv dstorage.KV, c *pb.Compare) (int64, bool) {
if txnID == noTxn {
panic("applyCompare called with noTxn")
}
ckvs, rev, err := kv.TxnRange(txnID, c.Key, nil, 1, 0)
if err != nil {
if err == dstorage.ErrTxnIDMismatch {
panic("unexpected txn ID mismatch error")
}
return rev, false
}
var ckv storagepb.KeyValue
if len(ckvs) != 0 {
ckv = ckvs[0]
} else {
// Use the zero value of ckv normally. However...
if c.Target == pb.Compare_VALUE {
// Always fail if we're comparing a value on a key that doesn't exist.
// We can treat non-existence as the empty set explicitly, such that
// even a key with a value of length 0 bytes is still a real key
// that was written that way
return rev, false
}
}
// -1 is less, 0 is equal, 1 is greater
var result int
switch c.Target {
case pb.Compare_VALUE:
result = bytes.Compare(ckv.Value, c.Value)
case pb.Compare_CREATE:
result = compareInt64(ckv.CreateRevision, c.CreateRevision)
case pb.Compare_MOD:
result = compareInt64(ckv.ModRevision, c.ModRevision)
case pb.Compare_VERSION:
result = compareInt64(ckv.Version, c.Version)
}
switch c.Result {
case pb.Compare_EQUAL:
if result != 0 {
return rev, false
}
case pb.Compare_GREATER:
if result != 1 {
return rev, false
}
case pb.Compare_LESS:
if result != -1 {
return rev, false
}
}
return rev, true
}
// applyCompare applies the compare request.
// applyCompare should only be called within a txn request and an valid txn ID must
// be presented. Or applyCompare panics.
// It returns the revision at which the comparison happens. If the comparison
// succeeds, the it returns true. Otherwise it returns false.
func applyCompare(txnID int64, kv dstorage.KV, c *pb.Compare) (int64, bool) {
if txnID == noTxn {
panic("applyCompare called with noTxn")
}
ckvs, rev, err := kv.TxnRange(txnID, c.Key, nil, 1, 0)
if err != nil {
if err == dstorage.ErrTxnIDMismatch {
panic("unexpected txn ID mismatch error")
}
return rev, false
}
ckv := ckvs[0]
// -1 is less, 0 is equal, 1 is greater
var result int
switch c.Target {
case pb.Compare_VALUE:
result = bytes.Compare(ckv.Value, c.Value)
case pb.Compare_CREATE:
result = compareInt64(ckv.CreateRevision, c.CreateRevision)
case pb.Compare_MOD:
result = compareInt64(ckv.ModRevision, c.ModRevision)
case pb.Compare_VERSION:
result = compareInt64(ckv.Version, c.Version)
}
switch c.Result {
case pb.Compare_EQUAL:
if result != 0 {
return rev, false
}
case pb.Compare_GREATER:
if result != 1 {
return rev, false
}
case pb.Compare_LESS:
if result != -1 {
return rev, false
}
}
return rev, true
}
func applyRange(txnID int64, kv dstorage.KV, r *pb.RangeRequest) (*pb.RangeResponse, error) {
resp := &pb.RangeResponse{}
resp.Header = &pb.ResponseHeader{}
var (
kvs []storagepb.KeyValue
rev int64
err error
)
// grpc sends empty byte strings as nils, so use a '\0' to indicate
// wanting a >= query
if len(r.RangeEnd) == 1 && r.RangeEnd[0] == 0 {
r.RangeEnd = []byte{}
}
limit := r.Limit
if r.SortOrder != pb.RangeRequest_NONE {
// fetch everything; sort and truncate afterwards
limit = 0
}
if limit > 0 {
// fetch one extra for 'more' flag
limit = limit + 1
}
if txnID != noTxn {
kvs, rev, err = kv.TxnRange(txnID, r.Key, r.RangeEnd, limit, r.Revision)
if err != nil {
return nil, err
}
} else {
kvs, rev, err = kv.Range(r.Key, r.RangeEnd, limit, r.Revision)
if err != nil {
return nil, err
}
}
if r.SortOrder != pb.RangeRequest_NONE {
var sorter sort.Interface
switch {
case r.SortTarget == pb.RangeRequest_KEY:
sorter = &kvSortByKey{&kvSort{kvs}}
case r.SortTarget == pb.RangeRequest_VERSION:
sorter = &kvSortByVersion{&kvSort{kvs}}
case r.SortTarget == pb.RangeRequest_CREATE:
sorter = &kvSortByCreate{&kvSort{kvs}}
case r.SortTarget == pb.RangeRequest_MOD:
sorter = &kvSortByMod{&kvSort{kvs}}
case r.SortTarget == pb.RangeRequest_VALUE:
sorter = &kvSortByValue{&kvSort{kvs}}
}
switch {
case r.SortOrder == pb.RangeRequest_ASCEND:
sort.Sort(sorter)
case r.SortOrder == pb.RangeRequest_DESCEND:
sort.Sort(sort.Reverse(sorter))
}
}
if r.Limit > 0 && len(kvs) > int(r.Limit) {
kvs = kvs[:r.Limit]
resp.More = true
}
resp.Header.Revision = rev
for i := range kvs {
resp.Kvs = append(resp.Kvs, &kvs[i])
}
return resp, nil
}