Added README

README.md

@@ -0,0 +1,98 @@
+![Build and test](https://github.com/vooft/pg-kueue/actions/workflows/build.yml/badge.svg?branch=main)
+![Releases](https://img.shields.io/github/v/release/vooft/pg-kueue)
+![Maven Central](https://img.shields.io/maven-central/v/io.github.vooft/pg-kueue-core)
+![License](https://img.shields.io/github/license/vooft/pg-kueue)
+
+# pg-kueue
+Kotlin Coroutines PostgresSQL-based message queue using LISTEN/NOTIFY
+
+Everything is String-based and for now just follows normal LISTEN/NOTIFY rules.
+
+# Supported database SPIs
+This library was designed to be used with different SPIs, providing similar coroutines-based interface.
+
+Currently, only JDBC-based SPI is implemented + helper functions for jOOQ.
+
+## JDBC
+pg-kueue uses virtual threads to make any calls to the database in a non-blocking fashion.
+
+It works with any `java.sql.DataSource` implementation, reserving one connection for listening to notifications.
+
+# JDBC usage
+
+## Gradle
+```kotlin
+    repositories {
+        mavenCentral()
+    }
+
+    dependencies {
+        implementation("io.github.vooft:pg-kueue-jdbc:<version>")
+    }
+```
+
+## Simple usage
+```kotlin
+    val dataSource = createMyDataSource()
+
+    val kueue = Kueue.jdbc(dataSource)
+    val subscription = kueue.subscribe(KueueTopic("my_topic")) { message: String ->
+        println("Received message: $message")
+    }
+
+    kueue.send(KueueTopic("my_topic"), "Hello, world!")
+    // will print after a tiny delay: "Received message: Hello, world!"
+```
+
+You can close subscription, if you would like to stop a particular listener:
+```kotlin
+    subscription.close()
+```
+
+But it is not necessary if the the subscription should exist for the whole Kueue lifecycle.
+
+All subscriptions will be closed automatically when Kueue is closed:
+```kotlin
+    kueue.close()
+```
+
+## Transactional usage
+To send a message using existing transaction, you should provide the transactional connection.
+
+Normally, API accepts a instance of a wrapped connection `KueueConnection`, there is a helper method to create it:
+```kotlin
+    val transactionalConnection = myBeginTransaction()
+    kueue.send(KueueTopic("my_topic"), "Hello, world!", kueue.wrap(transactionalConnection))
+``` 
+
+There is also an extension function for a specific library to simplify transactional sending:
+```kotlin
+    val transactionalConnection = myBeginTransaction()
+    kueue.send(KueueTopic("my_topic"), "Hello, world!", transactionalConnection) // an extension function must be imported explicitly
+```
+
+# Additional modules
+## jOOQ JDBC
+There is a module that accepts a jOOQ `DSLContext` and provides a similar interface to the JDBC module.
+
+### Gradle
+```kotlin
+    repositories {
+        mavenCentral()
+    }
+
+    dependencies {
+        implementation("io.github.vooft:pg-kueue-jooq-jdbc:<version>")
+    }
+```
+
+### Usage
+```kotlin
+    val dslContext = createMyDslContext()
+
+    // there is a helper method to create a Kueue instance using, for example, a non-transactional DSLContext
+    val kueue = Kueue.jooq(dslContext)
+
+    // also there is an extension method that accepts a transactional DSLContext to send notification within a transaction
+    kueue.send(KueueTopic("my_topic"), "Hello, world!", myTransactionalDslContext)
+```

pg-kueue-jdbc/src/main/kotlin/io/github/vooft/kueue/jdbc/KueueJdbcExtension.kt

@@ -1,6 +1,7 @@
 package io.github.vooft.kueue.jdbc
 
 import io.github.vooft.kueue.Kueue
+import io.github.vooft.kueue.KueueTopic
 import io.github.vooft.kueue.impl.KueueImpl
 import java.sql.Connection
 import javax.sql.DataSource
@@ -9,3 +10,7 @@ fun Kueue.Companion.jdbc(dataSource: DataSource): Kueue<Connection, JdbcKueueCon
     connectionProvider = DataSourceKueueConnectionProvider(dataSource),
     pubSub = JdbcKueueConnectionPubSub()
 )
+
+suspend fun Kueue<Connection, JdbcKueueConnection>.send(topic: KueueTopic, message: String, transactionalConnection: Connection) {
+    send(topic, message, wrap(transactionalConnection))
+}