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Diffstat (limited to 'swarm/network/stream/intervals/intervals.go')
| -rw-r--r-- | swarm/network/stream/intervals/intervals.go | 206 |
1 files changed, 0 insertions, 206 deletions
diff --git a/swarm/network/stream/intervals/intervals.go b/swarm/network/stream/intervals/intervals.go deleted file mode 100644 index 562c3df9a..000000000 --- a/swarm/network/stream/intervals/intervals.go +++ /dev/null @@ -1,206 +0,0 @@ -// Copyright 2018 The go-ethereum Authors -// This file is part of the go-ethereum library. -// -// The go-ethereum library is free software: you can redistribute it and/or modify -// it under the terms of the GNU Lesser General Public License as published by -// the Free Software Foundation, either version 3 of the License, or -// (at your option) any later version. -// -// The go-ethereum library is distributed in the hope that it will be useful, -// but WITHOUT ANY WARRANTY; without even the implied warranty of -// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the -// GNU Lesser General Public License for more details. -// -// You should have received a copy of the GNU Lesser General Public License -// along with the go-ethereum library. If not, see <http://www.gnu.org/licenses/>. - -package intervals - -import ( - "bytes" - "fmt" - "strconv" - "sync" -) - -// Intervals store a list of intervals. Its purpose is to provide -// methods to add new intervals and retrieve missing intervals that -// need to be added. -// It may be used in synchronization of streaming data to persist -// retrieved data ranges between sessions. -type Intervals struct { - start uint64 - ranges [][2]uint64 - mu sync.RWMutex -} - -// New creates a new instance of Intervals. -// Start argument limits the lower bound of intervals. -// No range bellow start bound will be added by Add method or -// returned by Next method. This limit may be used for -// tracking "live" synchronization, where the sync session -// starts from a specific value, and if "live" sync intervals -// need to be merged with historical ones, it can be safely done. -func NewIntervals(start uint64) *Intervals { - return &Intervals{ - start: start, - } -} - -// Add adds a new range to intervals. Range start and end are values -// are both inclusive. -func (i *Intervals) Add(start, end uint64) { - i.mu.Lock() - defer i.mu.Unlock() - - i.add(start, end) -} - -func (i *Intervals) add(start, end uint64) { - if start < i.start { - start = i.start - } - if end < i.start { - return - } - minStartJ := -1 - maxEndJ := -1 - j := 0 - for ; j < len(i.ranges); j++ { - if minStartJ < 0 { - if (start <= i.ranges[j][0] && end+1 >= i.ranges[j][0]) || (start <= i.ranges[j][1]+1 && end+1 >= i.ranges[j][1]) { - if i.ranges[j][0] < start { - start = i.ranges[j][0] - } - minStartJ = j - } - } - if (start <= i.ranges[j][1] && end+1 >= i.ranges[j][1]) || (start <= i.ranges[j][0] && end+1 >= i.ranges[j][0]) { - if i.ranges[j][1] > end { - end = i.ranges[j][1] - } - maxEndJ = j - } - if end+1 <= i.ranges[j][0] { - break - } - } - if minStartJ < 0 && maxEndJ < 0 { - i.ranges = append(i.ranges[:j], append([][2]uint64{{start, end}}, i.ranges[j:]...)...) - return - } - if minStartJ >= 0 { - i.ranges[minStartJ][0] = start - } - if maxEndJ >= 0 { - i.ranges[maxEndJ][1] = end - } - if minStartJ >= 0 && maxEndJ >= 0 && minStartJ != maxEndJ { - i.ranges[maxEndJ][0] = start - i.ranges = append(i.ranges[:minStartJ], i.ranges[maxEndJ:]...) - } -} - -// Merge adds all the intervals from the m Interval to current one. -func (i *Intervals) Merge(m *Intervals) { - m.mu.RLock() - defer m.mu.RUnlock() - i.mu.Lock() - defer i.mu.Unlock() - - for _, r := range m.ranges { - i.add(r[0], r[1]) - } -} - -// Next returns the first range interval that is not fulfilled. Returned -// start and end values are both inclusive, meaning that the whole range -// including start and end need to be added in order to full the gap -// in intervals. -// Returned value for end is 0 if the next interval is after the whole -// range that is stored in Intervals. Zero end value represents no limit -// on the next interval length. -func (i *Intervals) Next() (start, end uint64) { - i.mu.RLock() - defer i.mu.RUnlock() - - l := len(i.ranges) - if l == 0 { - return i.start, 0 - } - if i.ranges[0][0] != i.start { - return i.start, i.ranges[0][0] - 1 - } - if l == 1 { - return i.ranges[0][1] + 1, 0 - } - return i.ranges[0][1] + 1, i.ranges[1][0] - 1 -} - -// Last returns the value that is at the end of the last interval. -func (i *Intervals) Last() (end uint64) { - i.mu.RLock() - defer i.mu.RUnlock() - - l := len(i.ranges) - if l == 0 { - return 0 - } - return i.ranges[l-1][1] -} - -// String returns a descriptive representation of range intervals -// in [] notation, as a list of two element vectors. -func (i *Intervals) String() string { - return fmt.Sprint(i.ranges) -} - -// MarshalBinary encodes Intervals parameters into a semicolon separated list. -// The first element in the list is base36-encoded start value. The following -// elements are two base36-encoded value ranges separated by comma. -func (i *Intervals) MarshalBinary() (data []byte, err error) { - d := make([][]byte, len(i.ranges)+1) - d[0] = []byte(strconv.FormatUint(i.start, 36)) - for j := range i.ranges { - r := i.ranges[j] - d[j+1] = []byte(strconv.FormatUint(r[0], 36) + "," + strconv.FormatUint(r[1], 36)) - } - return bytes.Join(d, []byte(";")), nil -} - -// UnmarshalBinary decodes data according to the Intervals.MarshalBinary format. -func (i *Intervals) UnmarshalBinary(data []byte) (err error) { - d := bytes.Split(data, []byte(";")) - l := len(d) - if l == 0 { - return nil - } - if l >= 1 { - i.start, err = strconv.ParseUint(string(d[0]), 36, 64) - if err != nil { - return err - } - } - if l == 1 { - return nil - } - - i.ranges = make([][2]uint64, 0, l-1) - for j := 1; j < l; j++ { - r := bytes.SplitN(d[j], []byte(","), 2) - if len(r) < 2 { - return fmt.Errorf("range %d has less then 2 elements", j) - } - start, err := strconv.ParseUint(string(r[0]), 36, 64) - if err != nil { - return fmt.Errorf("parsing the first element in range %d: %v", j, err) - } - end, err := strconv.ParseUint(string(r[1]), 36, 64) - if err != nil { - return fmt.Errorf("parsing the second element in range %d: %v", j, err) - } - i.ranges = append(i.ranges, [2]uint64{start, end}) - } - - return nil -} |