Add 'src/be/nikiroo/utils/' from commit '46add0670fdee4bd936a13fe2448c5e20a7ffd0a'

[fanfix.git] / src / be / nikiroo / utils / streams / Base64InputStream.java

diff --git a/src/be/nikiroo/utils/streams/Base64InputStream.java b/src/be/nikiroo/utils/streams/Base64InputStream.java
new file mode 100644 (file)
index 0000000..a3afaef
--- /dev/null
+++ b/src/be/nikiroo/utils/streams/Base64InputStream.java
@@ -0,0 +1,161 @@
+/*
+ * Copyright (C) 2010 The Android Open Source Project
+ *
+ * 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.
+ */
+
+package be.nikiroo.utils.streams;
+
+import java.io.FilterInputStream;
+import java.io.IOException;
+import java.io.InputStream;
+
+/**
+ * An InputStream that does Base64 decoding on the data read through
+ * it.
+ */
+public class Base64InputStream extends FilterInputStream {
+    private final Base64.Coder coder;
+
+    private static byte[] EMPTY = new byte[0];
+
+    private static final int BUFFER_SIZE = 2048;
+    private boolean eof;
+    private byte[] inputBuffer;
+    private int outputStart;
+    private int outputEnd;
+
+    /**
+     * An InputStream that performs Base64 decoding on the data read
+     * from the wrapped stream.
+     *
+     * @param in the InputStream to read the source data from
+     */
+    public Base64InputStream(InputStream in) {
+        this(in, false);
+    }
+
+    /**
+     * Performs Base64 encoding or decoding on the data read from the
+     * wrapped InputStream.
+     *
+     * @param in the InputStream to read the source data from
+     * @param flags bit flags for controlling the decoder; see the
+     *        constants in {@link Base64}
+     * @param encode true to encode, false to decode
+     *
+     * @hide
+     */
+    public Base64InputStream(InputStream in, boolean encode) {
+        super(in);
+        eof = false;
+        inputBuffer = new byte[BUFFER_SIZE];
+        if (encode) {
+            coder = new Base64.Encoder(Base64.NO_WRAP, null);
+        } else {
+            coder = new Base64.Decoder(Base64.NO_WRAP, null);
+        }
+        coder.output = new byte[coder.maxOutputSize(BUFFER_SIZE)];
+        outputStart = 0;
+        outputEnd = 0;
+    }
+
+    @Override
+       public boolean markSupported() {
+        return false;
+    }
+
+    @SuppressWarnings("sync-override")
+       @Override
+       public void mark(int readlimit) {
+        throw new UnsupportedOperationException();
+    }
+
+    @SuppressWarnings("sync-override")
+       @Override
+       public void reset() {
+        throw new UnsupportedOperationException();
+    }
+
+    @Override
+       public void close() throws IOException {
+        in.close();
+        inputBuffer = null;
+    }
+
+    @Override
+       public int available() {
+        return outputEnd - outputStart;
+    }
+
+    @Override
+       public long skip(long n) throws IOException {
+        if (outputStart >= outputEnd) {
+            refill();
+        }
+        if (outputStart >= outputEnd) {
+            return 0;
+        }
+        long bytes = Math.min(n, outputEnd-outputStart);
+        outputStart += bytes;
+        return bytes;
+    }
+
+    @Override
+       public int read() throws IOException {
+        if (outputStart >= outputEnd) {
+            refill();
+        }
+        if (outputStart >= outputEnd) {
+            return -1;
+        }
+        
+        return coder.output[outputStart++] & 0xff;
+    }
+
+    @Override
+       public int read(byte[] b, int off, int len) throws IOException {
+        if (outputStart >= outputEnd) {
+            refill();
+        }
+        if (outputStart >= outputEnd) {
+            return -1;
+        }
+        int bytes = Math.min(len, outputEnd-outputStart);
+        System.arraycopy(coder.output, outputStart, b, off, bytes);
+        outputStart += bytes;
+        return bytes;
+    }
+
+    /**
+     * Read data from the input stream into inputBuffer, then
+     * decode/encode it into the empty coder.output, and reset the
+     * outputStart and outputEnd pointers.
+     */
+    private void refill() throws IOException {
+        if (eof) return;
+        int bytesRead = in.read(inputBuffer);
+        boolean success;
+        if (bytesRead == -1) {
+            eof = true;
+            success = coder.process(EMPTY, 0, 0, true);
+        } else {
+            success = coder.process(inputBuffer, 0, bytesRead, false);
+        }
+        if (!success) {
+            throw new IOException("bad base-64");
+        }
+        outputEnd = coder.op;
+        outputStart = 0;
+    }
+}