Add support for MariaDB version pattern

src/main/java/io/asyncer/r2dbc/mysql/Capability.java

@@ -175,6 +175,11 @@ public final class Capability {
 
     private final long bitmap;
 
+    /**
+     * Checks if the connection is using MariaDB capabilities.
+     *
+     * @return if using MariaDB capabilities.
+     */
     public boolean isMariaDb() {
         return (bitmap & CLIENT_MYSQL) == 0;
     }

src/main/java/io/asyncer/r2dbc/mysql/ConnectionContext.java

@@ -98,6 +98,11 @@ public ZoneId getServerZoneId() {
         return serverZoneId;
     }
 
+    @Override
+    public boolean isMariaDb() {
+        return capability.isMariaDb() || serverVersion.isMariaDb();
+    }
+
     boolean shouldSetServerZoneId() {
         return serverZoneId == null;
     }

src/main/java/io/asyncer/r2dbc/mysql/MySqlColumnDescriptor.java

@@ -122,7 +122,7 @@ public Integer getScale() {
     @Override
     public CharCollation getCharCollation(CodecContext context) {
         return collationId == CharCollation.BINARY_ID ? context.getClientCollation() :
-            CharCollation.fromId(collationId, context.getServerVersion());
+            CharCollation.fromId(collationId, context);
     }
 
     @Override

src/main/java/io/asyncer/r2dbc/mysql/MySqlConnection.java

@@ -66,18 +66,13 @@ public final class MySqlConnection implements Connection, Lifecycle, ConnectionS
 
     private static final int PREFIX_LENGTH = 6;
 
-    /**
-     * If MySQL server version greater than or equal to {@literal 8.0.3}, or greater than or equal to
-     * {@literal 5.7.20} and less than {@literal 8.0.0}, the column name of current session isolation level
-     * will be {@literal @@transaction_isolation}, otherwise it is {@literal @@tx_isolation}.
-     *
-     * @see #init judge server version before get the isolation level.
-     */
-    private static final ServerVersion TRAN_LEVEL_8X = ServerVersion.create(8, 0, 3);
+    private static final ServerVersion MARIA_11_1_1 = ServerVersion.create(11, 1, 1, true);
 
-    private static final ServerVersion TRAN_LEVEL_5X = ServerVersion.create(5, 7, 20);
+    private static final ServerVersion MYSQL_8_0_3 = ServerVersion.create(8, 0, 3);
 
-    private static final ServerVersion TX_LEVEL_8X = ServerVersion.create(8, 0, 0);
+    private static final ServerVersion MYSQL_5_7_20 = ServerVersion.create(5, 7, 20);
+
+    private static final ServerVersion MYSQL_8 = ServerVersion.create(8, 0, 0);
 
     private static final BiConsumer<ServerMessage, SynchronousSink<Boolean>> PING = (message, sink) -> {
         if (message instanceof ErrorMessage) {
@@ -427,17 +422,10 @@ static Mono<MySqlConnection> init(
         QueryCache queryCache, PrepareCache prepareCache,
         @Nullable Predicate<String> prepare
     ) {
-        ServerVersion version = context.getServerVersion();
-        StringBuilder query = new StringBuilder(128);
-
-        // Maybe create a InitFlow for data initialization after login?
-        if (version.isGreaterThanOrEqualTo(TRAN_LEVEL_8X) ||
-            (version.isGreaterThanOrEqualTo(TRAN_LEVEL_5X) && version.isLessThan(TX_LEVEL_8X))) {
-            query.append(
-                "SELECT @@transaction_isolation AS i,@@innodb_lock_wait_timeout AS l,@@version_comment AS v");
-        } else {
-            query.append("SELECT @@tx_isolation AS i,@@innodb_lock_wait_timeout AS l,@@version_comment AS v");
-        }
+        StringBuilder query = new StringBuilder(128)
+            .append("SELECT ")
+            .append(transactionIsolationColumn(context))
+            .append(",@@innodb_lock_wait_timeout AS l,@@version_comment AS v");
 
         Function<MySqlResult, Publisher<InitData>> handler;
 
@@ -587,6 +575,28 @@ private static long convertLockWaitTimeout(@Nullable Long timeout) {
         return timeout;
     }
 
+    /**
+     * Resolves the column of session isolation level, the {@literal @@tx_isolation} has been marked as
+     * deprecated.
+     * <p>
+     * If server is MariaDB, {@literal @@transaction_isolation} is used starting from {@literal 11.1.1}.
+     * <p>
+     * If the server is MySQL, use {@literal @@transaction_isolation} starting from {@literal 8.0.3}, or
+     * between {@literal 5.7.20} and {@literal 8.0.0} (exclusive).
+     */
+    private static String transactionIsolationColumn(ConnectionContext context) {
+        ServerVersion version = context.getServerVersion();
+
+        if (context.isMariaDb()) {
+            return version.isGreaterThanOrEqualTo(MARIA_11_1_1) ? "@@transaction_isolation AS i" :
+                "@@tx_isolation AS i";
+        }
+
+        return version.isGreaterThanOrEqualTo(MYSQL_8_0_3) ||
+            (version.isGreaterThanOrEqualTo(MYSQL_5_7_20) && version.isLessThan(MYSQL_8)) ?
+            "@@transaction_isolation AS i" : "@@tx_isolation AS i";
+    }
+
     private static class InitData {
 
         private final IsolationLevel level;

src/main/java/io/asyncer/r2dbc/mysql/ServerVersion.java

@@ -24,6 +24,13 @@
  */
 public final class ServerVersion implements Comparable<ServerVersion> {
 
+    /**
+     * MariaDB's replication hack prefix.
+     * <p>
+     * Note: MySQL 5.5.5 is not a stable version, so it should be safe.
+     */
+    private static final String MARIADB_RPL_HACK_PREFIX = "5.5.5-";
+
     private static final String ENTERPRISE = "enterprise";
 
     private static final String COMMERCIAL = "commercial";
@@ -42,11 +49,14 @@ public final class ServerVersion implements Comparable<ServerVersion> {
 
     private final int patch;
 
-    private ServerVersion(String origin, int major, int minor, int patch) {
+    private final boolean isMariaDb;
+
+    private ServerVersion(String origin, int major, int minor, int patch, boolean isMariaDb) {
         this.origin = origin;
         this.major = major;
         this.minor = minor;
         this.patch = patch;
+        this.isMariaDb = isMariaDb;
     }
 
     /**
@@ -97,6 +107,15 @@ public int getPatch() {
         return patch;
     }
 
+    /**
+     * Checks {@link ServerVersion this} contains MariaDB prefix or postfix.
+     *
+     * @return if it contains.
+     */
+    public boolean isMariaDb() {
+        return isMariaDb;
+    }
+
     /**
      * Checks if the version is enterprise edition.
      * <p>
@@ -150,32 +169,39 @@ public static ServerVersion parse(String version) {
 
         int length = version.length();
         int[] index = new int[] { 0 };
-        int major = readInt(version, length, index);
-
-        if (index[0] >= length) {
-            // End-of-string.
-            return create0(version, major, 0, 0);
-        } else if (version.charAt(index[0]) != '.') {
-            // Is not '.', has only postfix after major.
-            return create0(version, major, 0, 0);
-        } else {
-            // Skip last '.' after major.
-            ++index[0];
+        boolean isMariaDb = false;
+
+        if (version.startsWith(MARIADB_RPL_HACK_PREFIX)) {
+            isMariaDb = true;
+            index[0] = MARIADB_RPL_HACK_PREFIX.length();
         }
 
-        int minor = readInt(version, length, index);
+        int[] parts = new int[] { 0, 0, 0 };
+        int i = 0;
+
+        while (true) {
+            parts[i] = readInt(version, length, index);
 
-        if (index[0] >= length) {
-            return create0(version, major, minor, 0);
-        } else if (version.charAt(index[0]) != '.') {
-            // Is not '.', has only postfix after minor.
-            return create0(version, major, minor, 0);
-        } else {
-            // Skip last '.' after minor.
+            if (index[0] >= length) {
+                // End of version.
+                break;
+            }
+
+            if (i == 2 || version.charAt(index[0]) != '.') {
+                // End of version number parts, check postfix if needed.
+                if (!isMariaDb) {
+                    isMariaDb = version.indexOf("MariaDB", index[0]) >= 0;
+                }
+
+                break;
+            }
+
+            // Skip last '.' after current number part.
             ++index[0];
+            ++i;
         }
 
-        return create0(version, major, minor, readInt(version, length, index));
+        return create0(version, parts[0], parts[1], parts[2], isMariaDb);
     }
 
     /**
@@ -188,15 +214,29 @@ public static ServerVersion parse(String version) {
      * @throws IllegalArgumentException if any version part is negative integer.
      */
     public static ServerVersion create(int major, int minor, int patch) {
-        return create0("", major, minor, patch);
+        return create0("", major, minor, patch, false);
+    }
+
+    /**
+     * Create a {@link ServerVersion} that value is {@literal major.minor.patch} with MariaDB flag.
+     *
+     * @param major     must not be a negative integer
+     * @param minor     must not be a negative integer
+     * @param patch     must not be a negative integer
+     * @param isMariaDb MariaDB flag
+     * @return A server version that value is {@literal major.minor.patch}
+     * @throws IllegalArgumentException if any version part is negative integer.
+     */
+    public static ServerVersion create(int major, int minor, int patch, boolean isMariaDb) {
+        return create0("", major, minor, patch, isMariaDb);
     }
 
-    private static ServerVersion create0(String origin, int major, int minor, int patch) {
+    private static ServerVersion create0(String origin, int major, int minor, int patch, boolean isMariaDb) {
         require(major >= 0, "major version must not be a negative integer");
         require(minor >= 0, "minor version must not be a negative integer");
         require(patch >= 0, "patch version must not be a negative integer");
 
-        return new ServerVersion(origin, major, minor, patch);
+        return new ServerVersion(origin, major, minor, patch, isMariaDb);
     }
 
     /**

src/main/java/io/asyncer/r2dbc/mysql/client/SslBridgeHandler.java

@@ -63,13 +63,19 @@ final class SslBridgeHandler extends ChannelDuplexHandler {
 
     private static final String[] OLD_TLS_PROTOCOLS = new String[] { TlsVersions.TLS1_1, TlsVersions.TLS1 };
 
-    private static final ServerVersion VER_5_6_0 = ServerVersion.create(5, 6, 0);
+    private static final ServerVersion MARIA_10_2_16 = ServerVersion.create(10, 2, 16, true);
 
-    private static final ServerVersion VER_5_6_46 = ServerVersion.create(5, 6, 46);
+    private static final ServerVersion MARIA_10_3_0 = ServerVersion.create(10, 3, 0, true);
 
-    private static final ServerVersion VER_5_7_0 = ServerVersion.create(5, 7, 0);
+    private static final ServerVersion MARIA_10_3_8 = ServerVersion.create(10, 3, 8, true);
 
-    private static final ServerVersion VER_5_7_28 = ServerVersion.create(5, 7, 28);
+    private static final ServerVersion MYSQL_5_6_0 = ServerVersion.create(5, 6, 0);
+
+    private static final ServerVersion MYSQL_5_6_46 = ServerVersion.create(5, 6, 46);
+
+    private static final ServerVersion MYSQL_5_7_0 = ServerVersion.create(5, 7, 0);
+
+    private static final ServerVersion MYSQL_5_7_28 = ServerVersion.create(5, 7, 28);
 
     private final ConnectionContext context;
 
@@ -144,7 +150,7 @@ private void handleSslState(ChannelHandlerContext ctx, SslState state) {
                 logger.debug("SSL event triggered, enable SSL handler to pipeline");
 
                 SslProvider sslProvider = SslProvider.builder()
-                    .sslContext(MySqlSslContextSpec.forClient(ssl, context.getServerVersion()))
+                    .sslContext(MySqlSslContextSpec.forClient(ssl, context))
                     .build();
                 SslHandler sslHandler = sslProvider.getSslContext().newHandler(ctx.alloc());
 
@@ -167,13 +173,23 @@ private HostnameVerifier hostnameVerifier() {
         return verifier == null ? DefaultHostnameVerifier.INSTANCE : verifier;
     }
 
-    private static boolean isCurrentTlsEnabled(ServerVersion version) {
-        // See also https://dev.mysql.com/doc/connector-j/8.0/en/connector-j-reference-using-ssl.html
+    private static boolean isTls13Enabled(ConnectionContext context) {
+        ServerVersion version = context.getServerVersion();
+
+        if (context.isMariaDb()) {
+            // See also https://mariadb.com/kb/en/secure-connections-overview/#tls-protocol-version-support
+            // Quoting fragment: MariaDB binaries built with the OpenSSL library (OpenSSL 1.1.1 or later)
+            // support TLSv1.3 since MariaDB 10.2.16 and MariaDB 10.3.8.
+            return (version.isGreaterThanOrEqualTo(MARIA_10_2_16) && version.isLessThan(MARIA_10_3_0))
+                || version.isGreaterThanOrEqualTo(MARIA_10_3_8);
+        }
+
+        // See also https://dev.mysql.com/doc/relnotes/connector-j/en/news-8-0-19.html
         // Quoting fragment: TLSv1,TLSv1.1,TLSv1.2,TLSv1.3 for MySQL Community Servers 8.0, 5.7.28 and
         // later, and 5.6.46 and later, and for all commercial versions of MySQL Servers.
-        return version.isGreaterThanOrEqualTo(VER_5_7_28)
-            || (version.isGreaterThanOrEqualTo(VER_5_6_46) && version.isLessThan(VER_5_7_0))
-            || (version.isGreaterThanOrEqualTo(VER_5_6_0) && version.isEnterprise());
+        return version.isGreaterThanOrEqualTo(MYSQL_5_7_28)
+            || (version.isGreaterThanOrEqualTo(MYSQL_5_6_46) && version.isLessThan(MYSQL_5_7_0))
+            || (version.isGreaterThanOrEqualTo(MYSQL_5_6_0) && version.isEnterprise());
     }
 
     private static final class MySqlSslContextSpec implements SslProvider.ProtocolSslContextSpec {
@@ -196,7 +212,7 @@ public SslContext sslContext() throws SSLException {
             return builder.build();
         }
 
-        static MySqlSslContextSpec forClient(MySqlSslConfiguration ssl, ServerVersion version) {
+        static MySqlSslContextSpec forClient(MySqlSslConfiguration ssl, ConnectionContext context) {
             // Same default configuration as TcpSslContextSpec.
             SslContextBuilder builder = SslContextBuilder.forClient()
                 .sslProvider(OpenSsl.isAvailable() ? OPENSSL : JDK)
@@ -206,11 +222,16 @@ static MySqlSslContextSpec forClient(MySqlSslConfiguration ssl, ServerVersion ve
 
             if (tlsProtocols.length > 0) {
                 builder.protocols(tlsProtocols);
-            } else if (isCurrentTlsEnabled(version)) {
+            } else if (isTls13Enabled(context)) {
                 builder.protocols(TLS_PROTOCOLS);
             } else {
                 // Not sure if we need to check the JDK version, suggest not.
-                logger.warn("MySQL {} does not support TLS1.2, TLS1.1 is disabled in latest JDKs", version);
+                if (logger.isWarnEnabled()) {
+                    logger.warn("{} {} does not support TLS1.2, TLS1.1 is disabled in latest JDKs",
+                        context.isMariaDb() ? "MariaDB" : "MySQL",
+                        context.getServerVersion());
+                }
+
                 builder.protocols(OLD_TLS_PROTOCOLS);
             }
 

src/main/java/io/asyncer/r2dbc/mysql/codec/CodecContext.java

@@ -54,4 +54,11 @@ public interface CodecContext {
      * @return the {@link CharCollation}.
      */
     CharCollation getClientCollation();
+
+    /**
+     * Checks server is MariaDB or not.
+     *
+     * @return if is MariaDB.
+     */
+    boolean isMariaDb();
 }

src/main/java/io/asyncer/r2dbc/mysql/collation/CharCollation.java

@@ -16,7 +16,7 @@
 
 package io.asyncer.r2dbc.mysql.collation;
 
-import io.asyncer.r2dbc.mysql.ServerVersion;
+import io.asyncer.r2dbc.mysql.codec.CodecContext;
 
 import java.nio.charset.Charset;
 
@@ -62,17 +62,17 @@ public interface CharCollation {
 
     /**
      * Obtain an instance of {@link CharCollation} from the identifier and server version, if not found, it
-     * will fallback to UTF-8. (i.e. utf8mb4)
+     * will fall back to UTF-8. (i.e. utf8mb4)
      *
      * @param id      character collation identifier.
-     * @param version the version of MySQL server.
+     * @param context the codec context of server.
      * @return the {@link CharCollation}.
      * @throws IllegalArgumentException if {@code version} is {@code null}.
      */
-    static CharCollation fromId(int id, ServerVersion version) {
-        requireNonNull(version, "version must not be null");
+    static CharCollation fromId(int id, CodecContext context) {
+        requireNonNull(context, "version must not be null");
 
-        return CharCollations.fromId(id, version);
+        return CharCollations.fromId(id, context);
     }
 
     /**