Sho SHIMIZU | fc932d5 | 2014-08-15 11:22:37 -0700 | [diff] [blame] | 1 | package net.onrc.onos.core.util; |
Jonathan Hart | 1530ccc | 2013-04-03 19:36:02 -0700 | [diff] [blame] | 2 | |
Yuta HIGUCHI | 992c70e | 2014-08-19 23:28:24 -0700 | [diff] [blame] | 3 | import java.util.concurrent.atomic.AtomicLong; |
| 4 | |
| 5 | import javax.annotation.concurrent.ThreadSafe; |
| 6 | |
Sho SHIMIZU | 9257b0c | 2014-08-13 15:00:10 -0700 | [diff] [blame] | 7 | import com.google.common.base.Objects; |
Sho SHIMIZU | 9257b0c | 2014-08-13 15:00:10 -0700 | [diff] [blame] | 8 | |
| 9 | import static com.google.common.base.Preconditions.checkArgument; |
| 10 | |
| 11 | /** |
Yuta HIGUCHI | 992c70e | 2014-08-19 23:28:24 -0700 | [diff] [blame] | 12 | * A class representing an ID space. |
Sho SHIMIZU | 9257b0c | 2014-08-13 15:00:10 -0700 | [diff] [blame] | 13 | */ |
Yuta HIGUCHI | 992c70e | 2014-08-19 23:28:24 -0700 | [diff] [blame] | 14 | @ThreadSafe |
Sho SHIMIZU | 9257b0c | 2014-08-13 15:00:10 -0700 | [diff] [blame] | 15 | public final class IdBlock { |
Jonathan Hart | 12a26aa | 2014-06-04 14:33:09 -0700 | [diff] [blame] | 16 | private final long start; |
Jonathan Hart | 12a26aa | 2014-06-04 14:33:09 -0700 | [diff] [blame] | 17 | private final long size; |
Jonathan Hart | 1530ccc | 2013-04-03 19:36:02 -0700 | [diff] [blame] | 18 | |
Yuta HIGUCHI | 992c70e | 2014-08-19 23:28:24 -0700 | [diff] [blame] | 19 | private AtomicLong currentId; |
Sho SHIMIZU | 9257b0c | 2014-08-13 15:00:10 -0700 | [diff] [blame] | 20 | |
| 21 | /** |
| 22 | * Constructs a new ID block with the specified size and initial value. |
| 23 | * |
| 24 | * @param start initial value of the block |
| 25 | * @param size size of the block |
| 26 | * @throws IllegalArgumentException if the size is less than or equal to 0 |
| 27 | */ |
| 28 | public IdBlock(long start, long size) { |
| 29 | checkArgument(size > 0, "size should be more than 0, but %s", size); |
| 30 | |
Ray Milkey | 269ffb9 | 2014-04-03 14:43:30 -0700 | [diff] [blame] | 31 | this.start = start; |
Ray Milkey | 269ffb9 | 2014-04-03 14:43:30 -0700 | [diff] [blame] | 32 | this.size = size; |
Sho SHIMIZU | 9257b0c | 2014-08-13 15:00:10 -0700 | [diff] [blame] | 33 | |
Yuta HIGUCHI | 992c70e | 2014-08-19 23:28:24 -0700 | [diff] [blame] | 34 | this.currentId = new AtomicLong(start); |
Ray Milkey | 269ffb9 | 2014-04-03 14:43:30 -0700 | [diff] [blame] | 35 | } |
Jonathan Hart | 1530ccc | 2013-04-03 19:36:02 -0700 | [diff] [blame] | 36 | |
Sho SHIMIZU | 9257b0c | 2014-08-13 15:00:10 -0700 | [diff] [blame] | 37 | // TODO: consider if this method is needed or not |
| 38 | /** |
| 39 | * Returns the initial value. |
| 40 | * |
| 41 | * @return initial value |
| 42 | */ |
Ray Milkey | 269ffb9 | 2014-04-03 14:43:30 -0700 | [diff] [blame] | 43 | public long getStart() { |
| 44 | return start; |
| 45 | } |
| 46 | |
Sho SHIMIZU | 9257b0c | 2014-08-13 15:00:10 -0700 | [diff] [blame] | 47 | // TODO: consider if this method is needed or not |
| 48 | /** |
| 49 | * Returns the last value. |
| 50 | * |
| 51 | * @return last value |
| 52 | */ |
Ray Milkey | 269ffb9 | 2014-04-03 14:43:30 -0700 | [diff] [blame] | 53 | public long getEnd() { |
Sho SHIMIZU | 9257b0c | 2014-08-13 15:00:10 -0700 | [diff] [blame] | 54 | return start + size - 1; |
Ray Milkey | 269ffb9 | 2014-04-03 14:43:30 -0700 | [diff] [blame] | 55 | } |
| 56 | |
Sho SHIMIZU | 9257b0c | 2014-08-13 15:00:10 -0700 | [diff] [blame] | 57 | /** |
| 58 | * Returns the block size. |
| 59 | * |
| 60 | * @return block size |
| 61 | */ |
Ray Milkey | 269ffb9 | 2014-04-03 14:43:30 -0700 | [diff] [blame] | 62 | public long getSize() { |
| 63 | return size; |
| 64 | } |
| 65 | |
Sho SHIMIZU | 9257b0c | 2014-08-13 15:00:10 -0700 | [diff] [blame] | 66 | /** |
| 67 | * Returns the next ID in the block. |
| 68 | * |
| 69 | * @return next ID |
| 70 | * @throws UnavailableIdException if there is no available ID in the block. |
| 71 | */ |
| 72 | public long getNextId() { |
Yuta HIGUCHI | 992c70e | 2014-08-19 23:28:24 -0700 | [diff] [blame] | 73 | final long id = currentId.getAndIncrement(); |
| 74 | if (id > getEnd()) { |
Sho SHIMIZU | 9257b0c | 2014-08-13 15:00:10 -0700 | [diff] [blame] | 75 | throw new UnavailableIdException(String.format( |
Yuta HIGUCHI | 992c70e | 2014-08-19 23:28:24 -0700 | [diff] [blame] | 76 | "used all IDs in allocated space (size: %d, end: %d, current: %d)", |
| 77 | size, getEnd(), id |
Sho SHIMIZU | 9257b0c | 2014-08-13 15:00:10 -0700 | [diff] [blame] | 78 | )); |
| 79 | } |
Sho SHIMIZU | 9257b0c | 2014-08-13 15:00:10 -0700 | [diff] [blame] | 80 | |
| 81 | return id; |
| 82 | } |
| 83 | |
Yuta HIGUCHI | 992c70e | 2014-08-19 23:28:24 -0700 | [diff] [blame] | 84 | // TODO: Do we really need equals and hashCode? Should it contain currentId? |
Sho SHIMIZU | 9257b0c | 2014-08-13 15:00:10 -0700 | [diff] [blame] | 85 | @Override |
| 86 | public boolean equals(Object o) { |
| 87 | if (this == o) { |
| 88 | return true; |
| 89 | } |
| 90 | if (o == null || getClass() != o.getClass()) { |
| 91 | return false; |
| 92 | } |
| 93 | |
| 94 | IdBlock that = (IdBlock) o; |
| 95 | return Objects.equal(this.start, that.start) |
| 96 | && Objects.equal(this.size, that.size) |
Yuta HIGUCHI | 992c70e | 2014-08-19 23:28:24 -0700 | [diff] [blame] | 97 | && Objects.equal(this.currentId.get(), that.currentId.get()); |
Sho SHIMIZU | 9257b0c | 2014-08-13 15:00:10 -0700 | [diff] [blame] | 98 | } |
| 99 | |
| 100 | @Override |
| 101 | public int hashCode() { |
| 102 | return Objects.hashCode(start, size, currentId); |
| 103 | } |
| 104 | |
Ray Milkey | 269ffb9 | 2014-04-03 14:43:30 -0700 | [diff] [blame] | 105 | @Override |
| 106 | public String toString() { |
Sho SHIMIZU | 9257b0c | 2014-08-13 15:00:10 -0700 | [diff] [blame] | 107 | return Objects.toStringHelper(getClass()) |
| 108 | .add("start", start) |
| 109 | .add("size", size) |
| 110 | .add("currentId", currentId) |
| 111 | .toString(); |
Ray Milkey | 269ffb9 | 2014-04-03 14:43:30 -0700 | [diff] [blame] | 112 | } |
Jonathan Hart | 1530ccc | 2013-04-03 19:36:02 -0700 | [diff] [blame] | 113 | } |