X-Git-Url: http://git.nikiroo.be/?p=nikiroo-utils.git;a=blobdiff_plain;f=src%2Fbe%2Fnikiroo%2Futils%2Fstreams%2FBase64InputStream.java;fp=src%2Fbe%2Fnikiroo%2Futils%2Fstreams%2FBase64InputStream.java;h=b2357419696c67bf54d1393b92af6e044d72c039;hp=0000000000000000000000000000000000000000;hb=54ceddcd4c023fa4164ee5a8409878e93d9f05ad;hpb=f625b17522345692e737498597479b2207ef04ac

diff --git a/src/be/nikiroo/utils/streams/Base64InputStream.java b/src/be/nikiroo/utils/streams/Base64InputStream.java
new file mode 100644
index 0000000..b235741
--- /dev/null
+++ b/src/be/nikiroo/utils/streams/Base64InputStream.java
@@ -0,0 +1,151 @@
+/*
+ * 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;
+    }
+
+    public boolean markSupported() {
+        return false;
+    }
+
+    public void mark(int readlimit) {
+        throw new UnsupportedOperationException();
+    }
+
+    public void reset() {
+        throw new UnsupportedOperationException();
+    }
+
+    public void close() throws IOException {
+        in.close();
+        inputBuffer = null;
+    }
+
+    public int available() {
+        return outputEnd - outputStart;
+    }
+
+    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;
+    }
+
+    public int read() throws IOException {
+        if (outputStart >= outputEnd) {
+            refill();
+        }
+        if (outputStart >= outputEnd) {
+            return -1;
+        } else {
+            return coder.output[outputStart++] & 0xff;
+        }
+    }
+
+    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;
+    }
+}