1 files changed, 150 insertions, 0 deletions
diff --git a/subsonic-main/src/main/java/net/sourceforge/subsonic/io/RangeOutputStream.java b/subsonic-main/src/main/java/net/sourceforge/subsonic/io/RangeOutputStream.java
new file mode 100644
index 00000000..25bc03d2
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+++ b/subsonic-main/src/main/java/net/sourceforge/subsonic/io/RangeOutputStream.java
@@ -0,0 +1,150 @@
+/*
+ This file is part of Subsonic.
+
+ Subsonic is free software: you can redistribute it and/or modify
+ it under the terms of the GNU General Public License as published by
+ the Free Software Foundation, either version 3 of the License, or
+ (at your option) any later version.
+
+ Subsonic 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 General Public License for more details.
+
+ You should have received a copy of the GNU General Public License
+ along with Subsonic.  If not, see <http://www.gnu.org/licenses/>.
+
+ Copyright 2009 (C) Sindre Mehus
+ */
+package net.sourceforge.subsonic.io;
+
+import org.apache.commons.lang.math.Range;
+
+import java.io.FilterOutputStream;
+import java.io.IOException;
+import java.io.OutputStream;
+
+
+/**
+ * Special output stream for grabbing only part of a passed stream.
+ *
+ * @author Sindre Mehus (based on code found on http://www.koders.com/
+ */
+public class RangeOutputStream extends FilterOutputStream {
+
+    /**
+     * The starting index.
+     */
+    private long start;
+
+    /**
+     * The ending index.
+     */
+    private long end;
+
+    /**
+     * The current position.
+     */
+    protected long pos;
+
+    /**
+     * Wraps the given output stream in a RangeOutputStream, using the values
+     * in the given range, unless the range is <code>null</code> in which case
+     * the original OutputStream is returned.
+     *
+     * @param out   The output stream to wrap in a RangeOutputStream.
+     * @param range The range, may be <code>null</code>.
+     * @return The possibly wrapped output stream.
+     */
+    public static OutputStream wrap(OutputStream out, Range range) {
+        if (range == null) {
+            return out;
+        }
+        return new RangeOutputStream(out, range.getMinimumLong(), range.getMaximumLong());
+    }
+
+    /**
+     * Creates the stream with the passed start and end.
+     *
+     * @param out   The stream to write to.
+     * @param start The starting position.
+     * @param end   The ending position.
+     */
+    public RangeOutputStream(OutputStream out, long start, long end) {
+        super(out);
+        this.start = start;
+        this.end = end;
+        pos = 0;
+    }
+
+    /**
+     * Writes the byte IF it is within the range, otherwise it only
+     * increments the position.
+     *
+     * @param b The byte to write.
+     * @throws IOException Thrown if there was a problem writing to the stream.
+     */
+    @Override
+    public void write(int b) throws IOException {
+        if ((pos >= start) && (pos <= end)) {
+            super.write(b);
+        }
+        pos++;
+    }
+
+    /**
+     * Writes the bytes IF it is within the range, otherwise it only
+     * increments the position.
+     *
+     * @param b   The bytes to write.
+     * @param off The offset to start at.
+     * @param len The length to write.
+     * @throws IOException Thrown if there was a problem writing to the stream.
+     */
+    @Override
+    public void write(byte[] b, int off, int len) throws IOException {
+        boolean allowWrite = false;
+        long newPos = pos + off, newOff = off, newLen = len;
+
+        // Check to see if we are in the range
+        if (newPos <= end) {
+            if (newPos >= start) {
+                // We are so check to make sure we don't leave it
+                if (newPos + newLen > end) {
+                    newLen = end - newPos;
+                }
+
+                // Enable writing
+                allowWrite = true;
+            }
+
+            // We aren't yet in the range, but if see if the proposed write
+            // would place us there
+            else if (newPos + newLen >= start) {
+                // It would so, update the offset
+                newOff += start - newPos;
+
+                // New offset means, a new position, so update that too
+                newPos = newOff + pos;
+                newLen = len + (pos - newPos);
+
+                // Make sure we don't go past the range
+                if (newPos + newLen > end) {
+                    newLen = end - newPos;
+                }
+
+                // Enable writting
+                allowWrite = true;
+            }
+        }
+
+        // If we have enabled writing, do the write!
+        if (allowWrite) {
+            out.write(b, (int) newOff, (int) newLen);
+        }
+
+        // Move the cursor along
+        pos += off + len;
+    }
+}
+