[jOOQ/jOOQ#9426] DSLContext.meta(Source...) should be able to read InformationSchema from sources

jOOQ/src/main/java/org/jooq/DSLContext.java

@@ -297,19 +297,22 @@ public interface DSLContext extends Scope , AutoCloseable  {
      */
     Meta meta(InformationSchema schema);
 
-    /***
-     * Access the database meta data for a database represented by a list of DDL
-     * scripts. The DDL scripts will be parsed using {@link #parser()}, which in
-     * turn uses the relevant {@link #settings() settings} (e.g.
-     * {@link Settings#getParseDialect()}) of this object.
+    /**
+     * Create meta data from a set of sources.
+     * <p>
+     * This method creates a {@link Meta} representation from a set of source
+     * content, which can be any of:
+     * <ul>
+     * <li>A set of DDL scripts, which will be parsed using
+     * {@link #parser()}.</li>
+     * <li>A set of XML files, which will be unmarshalled into
+     * {@link InformationSchema} objects.</li>
+     * </ul>
      * <p>
      * This will not connect to your database to get live meta information,
      * unlike {@link #meta()} and {@link #meta(DatabaseMetaData)}.
-     * <p>
-     * This method is for internal only. Do not reference directly.
      */
-    @Internal
-    Meta meta(Source... scripts);
+    Meta meta(Source... sources);
 
     /**
      * Convenience method for {@link Meta#informationSchema()}.

jOOQ/src/main/java/org/jooq/impl/DefaultDSLContext.java

@@ -440,8 +440,8 @@ public class DefaultDSLContext extends AbstractScope implements DSLContext, Seri
     }
 
     @Override
-    public Meta meta(Source... scripts) {
-        return new DDLMetaProvider(configuration(), scripts).provide();
+    public Meta meta(Source... sources) {
+        return new SourceMetaProvider(configuration(), sources).provide();
     }
 
     @Override

jOOQ/src/main/java/org/jooq/impl/InformationSchemaMetaProvider.java

@@ -40,6 +40,8 @@ package org.jooq.impl;
 import org.jooq.Configuration;
 import org.jooq.Meta;
 import org.jooq.MetaProvider;
+import org.jooq.Source;
+import org.jooq.util.jaxb.tools.MiniJAXB;
 import org.jooq.util.xml.jaxb.InformationSchema;
 
 /**
@@ -50,16 +52,33 @@ import org.jooq.util.xml.jaxb.InformationSchema;
  */
 public class InformationSchemaMetaProvider implements MetaProvider {
 
-    private final Configuration configuration;
+    private final Configuration     configuration;
     private final InformationSchema schema;
+    private final Source[]          sources;
+
+    public InformationSchemaMetaProvider(Configuration configuration, Source... sources) {
+        this.configuration = configuration;
+        this.schema = null;
+        this.sources = sources;
+    }
 
     public InformationSchemaMetaProvider(Configuration configuration, InformationSchema schema) {
         this.configuration = configuration;
         this.schema = schema;
+        this.sources = null;
     }
 
     @Override
     public Meta provide() {
-        return new InformationSchemaMetaImpl(configuration, schema);
+        InformationSchema s = schema;
+
+        if (s == null) {
+            s = new InformationSchema();
+
+            for (Source source : sources)
+                MiniJAXB.append(s, MiniJAXB.unmarshal(source.reader(), InformationSchema.class));
+        }
+
+        return new InformationSchemaMetaImpl(configuration, s);
     }
 }

jOOQ/src/main/java/org/jooq/impl/SourceMetaProvider.java

@@ -0,0 +1,93 @@
+/*
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *  http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ *
+ * Other licenses:
+ * -----------------------------------------------------------------------------
+ * Commercial licenses for this work are available. These replace the above
+ * ASL 2.0 and offer limited warranties, support, maintenance, and commercial
+ * database integrations.
+ *
+ * For more information, please visit: http://www.jooq.org/licenses
+ *
+ *
+ *
+ *
+ *
+ *
+ *
+ *
+ *
+ *
+ *
+ *
+ *
+ *
+ *
+ *
+ */
+package org.jooq.impl;
+
+import java.io.IOException;
+import java.io.Reader;
+import java.io.StringWriter;
+
+import org.jooq.Configuration;
+import org.jooq.Meta;
+import org.jooq.MetaProvider;
+import org.jooq.Source;
+
+
+/**
+ * A {@link MetaProvider} implementation that can handle different types of
+ * {@link Source} content.
+ *
+ * @author Lukas Eder
+ */
+final class SourceMetaProvider implements MetaProvider {
+
+    private final Configuration configuration;
+    private final Source[]      sources;
+
+    SourceMetaProvider(Configuration configuration, Source... sources) {
+        this.configuration = configuration;
+        this.sources = sources;
+    }
+
+    @Override
+    public final Meta provide() {
+        if (sources.length > 0) {
+            StringWriter w = new StringWriter();
+
+            try {
+                Reader r = sources[0].reader();
+                char[] buffer = new char[8192];
+                int nRead;
+                while ((nRead = r.read(buffer, 0, 8192)) >= 0) {
+                    w.write(buffer, 0, nRead);
+                }
+            }
+            catch (IOException e) {
+                throw new org.jooq.exception.IOException("Could not read source", e);
+            }
+
+            String s = w.toString();
+            sources[0] = Source.of(w.toString());
+
+            // TODO: Implement more thorough and reusable "isXML()" check in MiniJAXB
+            if (s.startsWith("<?xml") || s.startsWith("<information_schema") || s.startsWith("<!--"))
+                return new InformationSchemaMetaProvider(configuration, sources).provide();
+        }
+
+        return new DDLMetaProvider(configuration, sources).provide();
+    }
+}

jOOQ/src/main/java/org/jooq/util/jaxb/tools/MiniJAXB.java

@@ -147,6 +147,10 @@ public final class MiniJAXB {
         }
     }
 
+    public static <T extends XMLAppendable> T unmarshal(Reader reader, Class<T> type) {
+        return unmarshal0(new InputSource(reader), type);
+    }
+
     public static <T extends XMLAppendable> T unmarshal(InputStream in, Class<T> type) {
         return unmarshal0(new InputSource(in), type);
     }