Add placement buffers + pipeline system

worldedit-core/src/main/java/com/sk89q/worldedit/reorder/arrange/Arranger.java

@@ -0,0 +1,44 @@
+/*
+ * WorldEdit, a Minecraft world manipulation toolkit
+ * Copyright (C) sk89q <http://www.sk89q.com>
+ * Copyright (C) WorldEdit team and contributors
+ *
+ * This program is free software: you can redistribute it and/or modify it
+ * under the terms of the GNU Lesser General Public License as published by the
+ * Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ * FITNESS FOR A PARTICULAR PURPOSE. See the GNU Lesser General Public License
+ * for more details.
+ *
+ * You should have received a copy of the GNU Lesser General Public License
+ * along with this program. If not, see <http://www.gnu.org/licenses/>.
+ */
+
+package com.sk89q.worldedit.reorder.arrange;
+
+import com.sk89q.worldedit.reorder.buffer.PlacementBuffer;
+
+/**
+ * (Re-)Arranges placement actions.
+ */
+public interface Arranger {
+
+    /**
+     * Re-arrange the given placements.
+     *
+     * @param stream the stream to pass re-arranged placements to
+     * @param buffer the new placements to arrange
+     */
+    void onWrite(PlacementOutputStream stream, PlacementBuffer buffer);
+
+    /**
+     * Called when a group of blocks ends.
+     *
+     * @param stream the stream to pass re-arranged placements to
+     */
+    void onFlush(PlacementOutputStream stream);
+
+}

worldedit-core/src/main/java/com/sk89q/worldedit/reorder/arrange/ArrangerPipeline.java

@@ -0,0 +1,51 @@
+/*
+ * WorldEdit, a Minecraft world manipulation toolkit
+ * Copyright (C) sk89q <http://www.sk89q.com>
+ * Copyright (C) WorldEdit team and contributors
+ *
+ * This program is free software: you can redistribute it and/or modify it
+ * under the terms of the GNU Lesser General Public License as published by the
+ * Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ * FITNESS FOR A PARTICULAR PURPOSE. See the GNU Lesser General Public License
+ * for more details.
+ *
+ * You should have received a copy of the GNU Lesser General Public License
+ * along with this program. If not, see <http://www.gnu.org/licenses/>.
+ */
+
+package com.sk89q.worldedit.reorder.arrange;
+
+import java.util.List;
+
+/**
+ * A sequential list of Arrangers.
+ *
+ * <p>
+ * The last Arranger <strong>MUST</strong> not touch its output stream.
+ * Instead, it should handle the actual placements.
+ * </p>
+ */
+public interface ArrangerPipeline {
+
+    static ArrangerPipeline create() {
+        return new ArrangerPipelineImpl();
+    }
+
+    /**
+     * The list of Arrangers. Use this to add to the pipeline.
+     *
+     * @return a mutable list of Arrangers
+     */
+    List<Arranger> arrangers();
+
+    /**
+     * Create a new stream to write messages to. It will use the Arrangers listed at this
+     * moment, copying them into the stream object.
+     */
+    PlacementOutputStream openStream();
+
+}

worldedit-core/src/main/java/com/sk89q/worldedit/reorder/arrange/ArrangerPipelineImpl.java

@@ -0,0 +1,78 @@
+/*
+ * WorldEdit, a Minecraft world manipulation toolkit
+ * Copyright (C) sk89q <http://www.sk89q.com>
+ * Copyright (C) WorldEdit team and contributors
+ *
+ * This program is free software: you can redistribute it and/or modify it
+ * under the terms of the GNU Lesser General Public License as published by the
+ * Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ * FITNESS FOR A PARTICULAR PURPOSE. See the GNU Lesser General Public License
+ * for more details.
+ *
+ * You should have received a copy of the GNU Lesser General Public License
+ * along with this program. If not, see <http://www.gnu.org/licenses/>.
+ */
+
+package com.sk89q.worldedit.reorder.arrange;
+
+import com.sk89q.worldedit.reorder.buffer.PlacementBuffer;
+
+import java.lang.reflect.Proxy;
+import java.util.List;
+import java.util.ListIterator;
+import java.util.concurrent.CopyOnWriteArrayList;
+
+import static com.google.common.base.Preconditions.checkState;
+
+class ArrangerPipelineImpl implements ArrangerPipeline {
+
+    // Make a stream that any interaction with will kill the parent stream.
+    private static final PlacementOutputStream UNUSABLE_PLACEMENT_OUTPUT_STREAM =
+        (PlacementOutputStream) Proxy.newProxyInstance(ArrangerPipelineImpl.class.getClassLoader(),
+            new Class[] { PlacementOutputStream.class }, (proxy, method, args) -> {
+                throw new IllegalStateException("Last Arranger interacted with output stream.");
+            });
+
+    private final List<Arranger> arrangers = new CopyOnWriteArrayList<>();
+
+    @Override
+    public List<Arranger> arrangers() {
+        return arrangers;
+    }
+
+    @Override
+    public PlacementOutputStream openStream() {
+        checkState(arrangers.size() > 0, "No Arrangers registered.");
+        ListIterator<Arranger> revIter = arrangers.listIterator(arrangers.size());
+        PlacementOutputStream prev = UNUSABLE_PLACEMENT_OUTPUT_STREAM;
+        while (revIter.hasPrevious()) {
+            prev = new PlacementOutputStreamImpl(revIter.previous(), prev);
+        }
+        return prev;
+    }
+
+    private static final class PlacementOutputStreamImpl implements PlacementOutputStream {
+        private final Arranger next;
+        private final PlacementOutputStream nextContext;
+
+        private PlacementOutputStreamImpl(Arranger next, PlacementOutputStream nextContext) {
+            this.next = next;
+            this.nextContext = nextContext;
+        }
+
+        @Override
+        public void write(PlacementBuffer buffer) {
+            next.onWrite(nextContext, buffer);
+        }
+
+        @Override
+        public void flush() {
+            next.onFlush(nextContext);
+        }
+    }
+
+}

worldedit-core/src/main/java/com/sk89q/worldedit/reorder/arrange/PlacementOutputStream.java

@@ -0,0 +1,46 @@
+/*
+ * WorldEdit, a Minecraft world manipulation toolkit
+ * Copyright (C) sk89q <http://www.sk89q.com>
+ * Copyright (C) WorldEdit team and contributors
+ *
+ * This program is free software: you can redistribute it and/or modify it
+ * under the terms of the GNU Lesser General Public License as published by the
+ * Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ * FITNESS FOR A PARTICULAR PURPOSE. See the GNU Lesser General Public License
+ * for more details.
+ *
+ * You should have received a copy of the GNU Lesser General Public License
+ * along with this program. If not, see <http://www.gnu.org/licenses/>.
+ */
+
+package com.sk89q.worldedit.reorder.arrange;
+
+import com.sk89q.worldedit.reorder.buffer.PlacementBuffer;
+
+/**
+ * Output interface for placements.
+ */
+public interface PlacementOutputStream {
+
+    /**
+     * Store or pass the given buffer to the next Arranger.
+     *
+     * <p>
+     * To ensure all data is written to the next Arranger, you <strong>must</strong> call
+     * {@link #flush()}!
+     * </p>
+     *
+     * @param buffer the placement buffer
+     */
+    void write(PlacementBuffer buffer);
+
+    /**
+     * Flush stored buffers to the next Arranger.
+     */
+    void flush();
+
+}

worldedit-core/src/main/java/com/sk89q/worldedit/reorder/buffer/BufferConditions.java

@@ -0,0 +1,63 @@
+/*
+ * WorldEdit, a Minecraft world manipulation toolkit
+ * Copyright (C) sk89q <http://www.sk89q.com>
+ * Copyright (C) WorldEdit team and contributors
+ *
+ * This program is free software: you can redistribute it and/or modify it
+ * under the terms of the GNU Lesser General Public License as published by the
+ * Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ * FITNESS FOR A PARTICULAR PURPOSE. See the GNU Lesser General Public License
+ * for more details.
+ *
+ * You should have received a copy of the GNU Lesser General Public License
+ * along with this program. If not, see <http://www.gnu.org/licenses/>.
+ */
+
+package com.sk89q.worldedit.reorder.buffer;
+
+import java.nio.BufferOverflowException;
+import java.nio.BufferUnderflowException;
+
+public class BufferConditions {
+
+    public static int checkWithin(int a, int b) {
+        if (a < 0 || a > b) {
+            throw new IllegalArgumentException();
+        }
+        return a;
+    }
+
+    public static void checkBounds(int dstLen, int off, int len) {
+        if (off < 0 || off > dstLen || len < 0 || len > (dstLen - off)) {
+            throw new IndexOutOfBoundsException();
+        }
+    }
+
+    public static int checkReadPosition(int position, int limit) {
+        if (position < 0 || position >= limit) {
+            throw new BufferUnderflowException();
+        }
+        return position;
+    }
+
+    public static int checkWritePosition(int position, int limit) {
+        if (position < 0 || position >= limit) {
+            throw new BufferOverflowException();
+        }
+        return position;
+    }
+
+    public static int checkIndex(int index, int limit) {
+        if (index < 0 || index >= limit) {
+            throw new IndexOutOfBoundsException();
+        }
+        return index;
+    }
+
+    private BufferConditions() {
+    }
+}