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本文次要钻研一下zset command
SortedSetAddCommand
claudb-1.7.1/src/main/java/com/github/tonivade/claudb/command/zset/SortedSetAddCommand.java
@Command("zadd")@ParamLength(3)@ParamType(DataType.ZSET)public class SortedSetAddCommand implements DBCommand { @Override public RedisToken execute(Database db, Request request) { try { DatabaseValue initial = db.getOrDefault(safeKey(request.getParam(0)), DatabaseValue.EMPTY_ZSET); DatabaseValue result = db.merge(safeKey(request.getParam(0)), parseInput(request), (oldValue, newValue) -> { Set<Entry<Double, SafeString>> merge = new SortedSet(); merge.addAll(oldValue.getSortedSet()); merge.addAll(newValue.getSortedSet()); return zset(merge); }); return integer(changed(initial.getSortedSet(), result.getSortedSet())); } catch (NumberFormatException e) { return error("ERR value is not a valid float"); } } private int changed(Set<Entry<Double, SafeString>> input, Set<Entry<Double, SafeString>> result) { return result.size() - input.size(); } private DatabaseValue parseInput(Request request) { Set<Entry<Double, SafeString>> set = new SortedSet(); SafeString score = null; for (SafeString string : request.getParams().stream().skip(1).collect(toList())) { if (score != null) { set.add(score(parseFloat(score.toString()), string)); score = null; } else { score = string; } } return zset(set); }}- SortedSetAddCommand实现了DBCommand接口，其execute办法先获取initial，而后执行db.merge办法，它先增加oldValue.getSortedSet()、再增加newValue.getSortedSet()
SortedSetCardinalityCommand
claudb-1.7.1/src/main/java/com/github/tonivade/claudb/command/zset/SortedSetCardinalityCommand.java
@ReadOnly@Command("zcard")@ParamLength(1)@ParamType(DataType.ZSET)public class SortedSetCardinalityCommand implements DBCommand { @Override public RedisToken execute(Database db, Request request) { DatabaseValue value = db.getOrDefault(safeKey(request.getParam(0)), DatabaseValue.EMPTY_ZSET); Set<Entry<Double, SafeString>> set = value.getSortedSet(); return integer(set.size()); }}- SortedSetCardinalityCommand实现了DBCommand接口，其execute办法先通过db.getOrDefault获取value，在获取value.getSortedSet()
SortedSetRemoveCommand
claudb-1.7.1/src/main/java/com/github/tonivade/claudb/command/zset/SortedSetRemoveCommand.java
@Command("zrem")@ParamLength(2)@ParamType(DataType.ZSET)public class SortedSetRemoveCommand implements DBCommand { @Override public RedisToken execute(Database db, Request request) { List<SafeString> items = request.getParams().stream().skip(1).collect(toList()); List<SafeString> removed = new LinkedList<>(); db.merge(safeKey(request.getParam(0)), DatabaseValue.EMPTY_ZSET, (oldValue, newValue) -> { Set<Entry<Double, SafeString>> merge = new SortedSet(); merge.addAll(oldValue.getSortedSet()); for (SafeString item : items) { if (merge.remove(score(0, item))) { removed.add(item); } } return zset(merge); }); return integer(removed.size()); }}- SortedSetRemoveCommand实现了DBCommand接口，其execute办法先从request参数提取items，而后执行db.merge，该办法遍历items挨个执行merge.remove(score(0, item))
SortedSetRangeCommand
claudb-1.7.1/src/main/java/com/github/tonivade/claudb/command/zset/SortedSetRangeCommand.java
@ReadOnly@Command("zrange")@ParamLength(3)@ParamType(DataType.ZSET)public class SortedSetRangeCommand implements DBCommand { private static final String PARAM_WITHSCORES = "WITHSCORES"; @Override public RedisToken execute(Database db, Request request) { try { DatabaseValue value = db.getOrDefault(safeKey(request.getParam(0)), DatabaseValue.EMPTY_ZSET); NavigableSet<Entry<Double, SafeString>> set = value.getSortedSet(); int from = Integer.parseInt(request.getParam(1).toString()); if (from < 0) { from = set.size() + from; } int to = Integer.parseInt(request.getParam(2).toString()); if (to < 0) { to = set.size() + to; } List<Object> result = emptyList(); if (from <= to) { Option<SafeString> withScores = request.getOptionalParam(3); if (withScores.isPresent() && withScores.get().toString().equalsIgnoreCase(PARAM_WITHSCORES)) { result = set.stream().skip(from).limit((to - from) + 1l) .flatMap(entry -> Stream.of(entry.getValue(), entry.getKey())).collect(toList()); } else { result = set.stream().skip(from).limit((to - from) + 1l) .map(Entry::getValue).collect(toList()); } } return convert(result); } catch (NumberFormatException e) { return error("ERR value is not an integer or out of range"); } }}- SortedSetRangeCommand实现了DBCommand接口，其execute办法执行db.getOrDefault获取value，而后通过set.stream().skip(from).limit((to - from) + 1l)获取result
SortedSetRangeByScoreCommand
claudb-1.7.1/src/main/java/com/github/tonivade/claudb/command/zset/SortedSetRangeByScoreCommand.java
@ReadOnly@Command("zrangebyscore")@ParamLength(3)@ParamType(DataType.ZSET)public class SortedSetRangeByScoreCommand implements DBCommand { private static final String EXCLUSIVE = "("; private static final String MINUS_INFINITY = "-inf"; private static final String INIFITY = "+inf"; private static final String PARAM_WITHSCORES = "WITHSCORES"; private static final String PARAM_LIMIT = "LIMIT"; @Override public RedisToken execute(Database db, Request request) { try { DatabaseValue value = db.getOrDefault(safeKey(request.getParam(0)), DatabaseValue.EMPTY_ZSET); NavigableSet<Entry<Double, SafeString>> set = value.getSortedSet(); float from = parseRange(request.getParam(1).toString()); float to = parseRange(request.getParam(2).toString()); Options options = parseOptions(request); Set<Entry<Double, SafeString>> range = set.subSet( score(from, SafeString.EMPTY_STRING), inclusive(request.getParam(1)), score(to, SafeString.EMPTY_STRING), inclusive(request.getParam(2))); List<Object> result = emptyList(); if (from <= to) { if (options.withScores) { result = range.stream().flatMap( entry -> Stream.of(entry.getValue(), entry.getKey())).collect(toList()); } else { result = range.stream().map(Entry::getValue).collect(toList()); } if (options.withLimit) { result = result.stream().skip(options.offset).limit(options.count).collect(toList()); } } return convert(result); } catch (NumberFormatException e) { return error("ERR value is not an float or out of range"); } } private Options parseOptions(Request request) { Options options = new Options(); for (int i = 3; i < request.getLength(); i++) { String param = request.getParam(i).toString(); if (param.equalsIgnoreCase(PARAM_LIMIT)) { options.withLimit = true; options.offset = parseInt(request.getParam(++i).toString()); options.count = parseInt(request.getParam(++i).toString()); } else if (param.equalsIgnoreCase(PARAM_WITHSCORES)) { options.withScores = true; } } return options; } private boolean inclusive(SafeString param) { return !param.toString().startsWith(EXCLUSIVE); } private float parseRange(String param) { switch (param) { case INIFITY: return Float.MAX_VALUE; case MINUS_INFINITY: return Float.MIN_VALUE; default: if (param.startsWith(EXCLUSIVE)) { return Float.parseFloat(param.substring(1)); } return Float.parseFloat(param); } } private static class Options { private boolean withScores; private boolean withLimit; private int offset; private int count; }}- SortedSetRangeByScoreCommand实现了DBCommand接口，其execute办法执行db.getOrDefault获取value，而后通过set.subSet(score(from, SafeString.EMPTY_STRING), inclusive(request.getParam(1)),score(to, SafeString.EMPTY_STRING), inclusive(request.getParam(2)))获取range，最初从range提取result
SortedSetReverseRangeCommand
claudb-1.7.1/src/main/java/com/github/tonivade/claudb/command/zset/SortedSetReverseRangeCommand.java
@ReadOnly@Command("zrevrange")@ParamLength(3)@ParamType(DataType.ZSET)public class SortedSetReverseRangeCommand implements DBCommand { private static final String PARAM_WITHSCORES = "WITHSCORES"; @Override public RedisToken execute(Database db, Request request) { try { DatabaseValue value = db.getOrDefault(safeKey(request.getParam(0)), DatabaseValue.EMPTY_ZSET); NavigableSet<Entry<Double, SafeString>> set = value.getSortedSet(); int from = Integer.parseInt(request.getParam(2).toString()); if (from < 0) { from = set.size() + from; } int to = Integer.parseInt(request.getParam(1).toString()); if (to < 0) { to = set.size() + to; } List<Object> result = emptyList(); if (from <= to) { Option<SafeString> withScores = request.getOptionalParam(3); if (withScores.isPresent() && withScores.get().toString().equalsIgnoreCase(PARAM_WITHSCORES)) { result = set.stream().skip(from).limit((to - from) + 1l) .flatMap(item -> Stream.of(item.getValue(), item.getKey())).collect(toList()); } else { result = set.stream().skip(from).limit((to - from) + 1l) .map(Entry::getValue).collect(toList()); } } reverse(result); return convert(result); } catch (NumberFormatException e) { return error("ERR value is not an integer or out of range"); } }}- SortedSetReverseRangeCommand实现了DBCommand接口，其execute办法执行db.getOrDefault获取value，而后通过set.stream().skip(from).limit((to - from) + 1l)获取result
SortedSetIncrementByCommand
claudb-1.7.1/src/main/java/com/github/tonivade/claudb/command/zset/SortedSetIncrementByCommand.java
@Command("zincrby")@ParamLength(3)@ParamType(DataType.ZSET)public class SortedSetIncrementByCommand implements DBCommand { @Override public RedisToken execute(Database db, Request request) { try { DatabaseKey zkey = safeKey(request.getParam(0)); DatabaseValue value = db.getOrDefault(zkey, DatabaseValue.EMPTY_ZSET); NavigableSet<Entry<Double, SafeString>> set = value.getSortedSet(); SafeString key = request.getParam(2); Double increment = Double.parseDouble(request.getParam(1).toString()); Entry<Double, SafeString> newValue = merge(set, key, increment); SortedSet result = new SortedSet(); result.addAll(set); result.remove(newValue); result.add(newValue); db.put(zkey, zset(result)); return string(newValue.getKey().toString()); } catch (NumberFormatException e) { return error("ERR value is not an integer or out of range"); } } private Entry<Double, SafeString> merge(NavigableSet<Entry<Double, SafeString>> set, SafeString key, Double increment) { return score(findByKey(set, key).getKey() + increment, key); } private Entry<Double, SafeString> findByKey(NavigableSet<Entry<Double, SafeString>> set, SafeString key) { // TODO: O(n) search, to fix forget the NavigableSet and use directly the SortedSet to get by key return set.stream().filter(entry -> entry.getValue().equals(key)).findFirst().orElse(score(0, key)); }}- SortedSetIncrementByCommand实现了DBCommand接口，其execute办法执行db.getOrDefault获取value，而后通过merge获取newValue
小结
claudb sorted set相干的command有SortedSetAddCommand、SortedSetCardinalityCommand、SortedSetRemoveCommand、SortedSetRangeCommand、SortedSetRangeByScoreCommand、SortedSetReverseRangeCommand、SortedSetIncrementByCommand
doc
- command/zset