1 files changed, 82 insertions, 0 deletions
diff --git a/src/main/java/com/kitfox/svg/xml/Base64InputStream.java b/src/main/java/com/kitfox/svg/xml/Base64InputStream.java
new file mode 100755
index 0000000..3851c39
--- /dev/null
+++ b/src/main/java/com/kitfox/svg/xml/Base64InputStream.java
@@ -0,0 +1,82 @@
+/*
+ * To change this template, choose Tools | Templates
+ * and open the template in the editor.
+ */
+
+package com.kitfox.svg.xml;
+
+import java.io.FilterInputStream;
+import java.io.IOException;
+import java.io.InputStream;
+
+/**
+ *
+ * @author kitfox
+ */
+public class Base64InputStream extends FilterInputStream
+{
+    int buf;  //Cached bytes to read
+    int bufSize;  //Number of bytes waiting to be read from buffer
+    boolean drain = false;  //After set, read no more chunks
+    
+    public Base64InputStream(InputStream in)
+    {
+        super(in);
+    }
+
+    public int read() throws IOException
+    {
+        if (drain && bufSize == 0)
+        {
+            return -1;
+        }
+        
+        if (bufSize == 0)
+        {
+            //Read next chunk into 4 byte buffer
+            int chunk = in.read();
+            if (chunk == -1)
+            {
+                drain = true;
+                return -1;
+            }
+            
+            //get remaining 3 bytes
+            for (int i = 0; i < 3; ++i)
+            {
+                int value = in.read();
+                if (value == -1)
+                {
+                    throw new IOException("Early termination of base64 stream");
+                }
+                chunk = (chunk << 8) | (value & 0xff);
+            }
+
+            //Check for special termination characters
+            if ((chunk & 0xffff) == (((byte)'=' << 8) | (byte)'='))
+            {
+                bufSize = 1;
+                drain = true;
+            }
+            else if ((chunk & 0xff) == (byte)'=')
+            {
+                bufSize = 2;
+                drain = true;
+            }
+            else
+            {
+                bufSize = 3;
+            }
+            
+            //Fill buffer with decoded characters
+            for (int i = 0; i < bufSize + 1; ++i)
+            {
+                buf = (buf << 6) | Base64Util.decodeByte((chunk >> 24) & 0xff);
+                chunk <<= 8;
+            }
+        }
+        
+        //Return nth remaing bte & decrement counter
+        return (buf >> (--bufSize * 8)) & 0xff;
+    } 
+}