/// <summary>
/// Similar to
/// <see cref="EncodeBytes(byte[], int, int, int)">EncodeBytes(byte[], int, int, int)
/// </see>
/// but returns
/// a byte array instead of instantiating a String. This is more efficient
/// if you're working with I/O streams and have large data sets to encode.
/// </summary>
/// <param name="source">The data to convert</param>
/// <param name="off">Offset in array where conversion should begin</param>
/// <param name="len">Length of data to convert</param>
/// <param name="options">Specified options</param>
/// <returns>The Base64-encoded data as a String</returns>
/// <seealso cref="Gzip">Gzip</seealso>
/// <seealso cref="DoBreakLines">DoBreakLines</seealso>
/// <exception cref="System.IO.IOException">if there is an error</exception>
/// <exception cref="System.ArgumentNullException">if source array is null</exception>
/// <exception cref="System.ArgumentException">if source array, offset, or length are invalid
/// </exception>
/// <since>2.3.1</since>
public static byte[] EncodeBytesToBytes(byte[] source, int off, int len, int options
)
{
if (source == null)
{
throw new ArgumentNullException("Cannot serialize a null array.");
}
// end if: null
if (off < 0)
{
throw new ArgumentException("Cannot have negative offset: " + off);
}
// end if: off < 0
if (len < 0)
{
throw new ArgumentException("Cannot have length offset: " + len);
}
// end if: len < 0
if (off + len > source.Length)
{
throw new ArgumentException(string.Format("Cannot have offset of %d and length of %d with array of length %d"
, off, len, source.Length));
}
// end if: off < 0
// Compress?
if ((options & Gzip) != 0)
{
ByteArrayOutputStream baos = null;
GZIPOutputStream gzos = null;
Base64.OutputStream b64os = null;
try
{
// GZip -> Base64 -> ByteArray
baos = new ByteArrayOutputStream();
b64os = new Base64.OutputStream(baos, Encode | options);
gzos = new GZIPOutputStream(b64os);
gzos.Write(source, off, len);
gzos.Close();
}
catch (IOException e)
{
// end try
// Catch it and then throw it immediately so that
// the finally{} block is called for cleanup.
throw;
}
finally
{
// end catch
try
{
gzos.Close();
}
catch (Exception)
{
}
try
{
b64os.Close();
}
catch (Exception)
{
}
try
{
baos.Close();
}
catch (Exception)
{
}
}
// end finally
return baos.ToByteArray();
}
else
{
// end if: compress
// Else, don't compress. Better not to use streams at all then.
bool breakLines = (options & DoBreakLines) != 0;
//int len43 = len * 4 / 3;
//byte[] outBuff = new byte[ ( len43 ) // Main 4:3
// + ( (len % 3) > 0 ? 4 : 0 ) // Account for padding
// + (breakLines ? ( len43 / MAX_LINE_LENGTH ) : 0) ]; // New lines
// Try to determine more precisely how big the array needs to be.
// If we get it right, we don't have to do an array copy, and
// we save a bunch of memory.
int encLen = (len / 3) * 4 + (len % 3 > 0 ? 4 : 0);
// Bytes needed for actual encoding
if (breakLines)
{
encLen += encLen / MaxLineLength;
}
// Plus extra newline characters
byte[] outBuff = new byte[encLen];
int d = 0;
int e = 0;
int len2 = len - 2;
int lineLength = 0;
for (; d < len2; d += 3, e += 4)
{
Encode3to4(source, d + off, 3, outBuff, e, options);
lineLength += 4;
if (breakLines && lineLength >= MaxLineLength)
{
outBuff[e + 4] = NewLine;
e++;
lineLength = 0;
}
}
// end if: end of line
// en dfor: each piece of array
if (d < len)
{
Encode3to4(source, d + off, len - d, outBuff, e, options);
e += 4;
}
// end if: some padding needed
// Only resize array if we didn't guess it right.
if (e <= outBuff.Length - 1)
{
// If breaking lines and the last byte falls right at
// the line length (76 bytes per line), there will be
// one extra byte, and the array will need to be resized.
// Not too bad of an estimate on array size, I'd say.
byte[] finalOut = new byte[e];
System.Array.Copy(outBuff, 0, finalOut, 0, e);
//System.err.println("Having to resize array from " + outBuff.length + " to " + e );
return finalOut;
}
else
{
//System.err.println("No need to resize array.");
return outBuff;
}
}
}
