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package io.lettuce.core;
import io.lettuce.core.internal.LettuceAssert;
import io.lettuce.core.protocol.CommandArgs;
import io.lettuce.core.protocol.CommandKeyword;
import java.time.Duration;
/**
* Argument list builder for the Redis XREAD and {@literal XREADGROUP} commands.
* Static import the methods from {@link XReadArgs.Builder} and call the methods: {@code block(…)} .
*
* {@link XReadArgs} is a mutable object and instances should be used only once to avoid shared mutable state.
*
* @author Mark Paluch
* @since 5.1
*/
public class XReadArgs implements CompositeArgument {
private Long block;
private Long count;
private boolean noack;
/**
* Builder entry points for {@link XReadArgs}.
*/
public static class Builder {
/**
* Utility constructor.
*/
private Builder() {
}
/**
* Create a new {@link XReadArgs} and set {@literal BLOCK}.
*
* @param milliseconds time to block.
* @return new {@link XReadArgs} with {@literal BLOCK} set.
* @see XReadArgs#block(long)
*/
public static XReadArgs block(long milliseconds) {
return new XReadArgs().block(milliseconds);
}
/**
* Create a new {@link XReadArgs} and set {@literal BLOCK}.
*
* @param timeout time to block.
* @return new {@link XReadArgs} with {@literal BLOCK} set.
* @see XReadArgs#block(Duration)
*/
public static XReadArgs block(Duration timeout) {
LettuceAssert.notNull(timeout, "Block timeout must not be null");
return block(timeout.toMillis());
}
/**
* Create a new {@link XReadArgs} and set {@literal COUNT}.
*
* @param count
* @return new {@link XReadArgs} with {@literal COUNT} set.
*/
public static XReadArgs count(long count) {
return new XReadArgs().count(count);
}
/**
* Create a new {@link XReadArgs} and set {@literal NOACK}.
*
* @return new {@link XReadArgs} with {@literal NOACK} set.
* @see XReadArgs#noack(boolean)
*/
public static XReadArgs noack() {
return noack(true);
}
/**
* Create a new {@link XReadArgs} and set {@literal NOACK}.
*
* @param noack
* @return new {@link XReadArgs} with {@literal NOACK} set.
* @see XReadArgs#noack(boolean)
*/
public static XReadArgs noack(boolean noack) {
return new XReadArgs().noack(noack);
}
}
/**
* Perform a blocking read and wait up to {@code milliseconds} for a new stream message.
*
* @param milliseconds max time to wait.
* @return {@code this}.
*/
public XReadArgs block(long milliseconds) {
this.block = milliseconds;
return this;
}
/**
* Perform a blocking read and wait up to a {@link Duration timeout} for a new stream message.
*
* @param timeout max time to wait.
* @return {@code this}.
*/
public XReadArgs block(Duration timeout) {
LettuceAssert.notNull(timeout, "Block timeout must not be null");
return block(timeout.toMillis());
}
/**
* Limit read to {@code count} messages.
*
* @param count number of messages.
* @return {@code this}.
*/
public XReadArgs count(long count) {
this.count = count;
return this;
}
/**
* Use NOACK option to disable auto-acknowledgement. Only valid for {@literal XREADGROUP}.
*
* @param noack {@code true} to disable auto-ack.
* @return {@code this}.
*/
public XReadArgs noack(boolean noack) {
this.noack = noack;
return this;
}
public void build(CommandArgs args) {
if (block != null) {
args.add(CommandKeyword.BLOCK).add(block);
}
if (count != null) {
args.add(CommandKeyword.COUNT).add(count);
}
if (noack) {
args.add(CommandKeyword.NOACK);
}
}
/**
* Value object representing a Stream with its offset.
*/
public static class StreamOffset {
final K name;
final String offset;
private StreamOffset(K name, String offset) {
this.name = name;
this.offset = offset;
}
/**
* Read all new arriving elements from the stream identified by {@code name} excluding any elements before this call
*
* @param name must not be {@code null}.
* @return the {@link StreamOffset} object without a specific offset.
*/
public static StreamOffset latest(K name) {
LettuceAssert.notNull(name, "Stream must not be null");
return new StreamOffset<>(name, "$");
}
/**
* Read all new arriving elements from the stream identified by {@code name} including the last element added before
* this call
*
* @param name must not be {@code null}.
* @return the {@link StreamOffset} object without a specific offset.
* @since 6.4
*/
public static StreamOffset last(K name) {
LettuceAssert.notNull(name, "Stream must not be null");
return new StreamOffset<>(name, "+");
}
/**
* Read all new arriving elements from the stream identified by {@code name} with ids greater than the last one consumed
* by the consumer group.
*
* @param name must not be {@code null}.
* @return the {@link StreamOffset} object without a specific offset.
*/
public static StreamOffset lastConsumed(K name) {
LettuceAssert.notNull(name, "Stream must not be null");
return new StreamOffset<>(name, ">");
}
/**
* Read all arriving elements from the stream identified by {@code name} starting at {@code offset}.
*
* @param name must not be {@code null}.
* @param offset the stream offset.
* @return the {@link StreamOffset} object without a specific offset.
*/
public static StreamOffset from(K name, String offset) {
LettuceAssert.notNull(name, "Stream must not be null");
LettuceAssert.notEmpty(offset, "Offset must not be empty");
return new StreamOffset<>(name, offset);
}
public K getName() {
return name;
}
public String getOffset() {
return offset;
}
@Override
public String toString() {
return String.format("%s:%s", name, offset);
}
}
}