StringBuilder but works with byte arrays.
* floating point is converted to a format suitable to the PDF.
* @author Paulo Soares (psoares@consiste.pt)
*/
public class ByteBuffer : Stream {
/** The count of bytes in the buffer. */
protected int count;
/** The buffer where the bytes are stored. */
protected byte[] buf;
private static int byteCacheSize = 0;
private static byte[][] byteCache = new byte[byteCacheSize][];
public const byte ZERO = (byte)'0';
private static char[] chars = new char[] {'0', '1', '2', '3', '4', '5', '6', '7', '8', '9'};
private static byte[] bytes = new byte[] {48, 49, 50, 51, 52, 53, 54, 55, 56, 57, 97, 98, 99, 100, 101, 102};
/**
* If true always output floating point numbers with 6 decimal digits.
* If false uses the faster, although less precise, representation.
*/
public static bool HIGH_PRECISION = false;
/** Creates new ByteBuffer with capacity 128 */
public ByteBuffer() : this(128) {}
/**
* Creates a byte buffer with a certain capacity.
* @param size the initial capacity
*/
public ByteBuffer(int size) {
if (size < 1)
size = 128;
buf = new byte[size];
}
/**
* Sets the cache size.
*
* This can only be used to increment the size.
* If the size that is passed through is smaller than the current size, nothing happens.
*
* @param size the size of the cache
*/
public static void SetCacheSize(int size) {
if (size > 3276700) size = 3276700;
if (size <= byteCacheSize) return;
byte[][] tmpCache = new byte[size][];
System.Array.Copy(byteCache, 0, tmpCache, 0, byteCacheSize);
byteCache = tmpCache;
byteCacheSize = size;
}
/**
* You can fill the cache in advance if you want to.
*
* @param decimals
*/
public static void FillCache(int decimals) {
int step = 1;
switch (decimals) {
case 0:
step = 100;
break;
case 1:
step = 10;
break;
}
for (int i = 1; i < byteCacheSize; i += step) {
if (byteCache[i] != null) continue;
byteCache[i] = ConvertToBytes(i);
}
}
/**
* Converts an double (multiplied by 100 and cast to an int) into an array of bytes.
*
* @param i the int
* @return a bytearray
*/
private static byte[] ConvertToBytes(int i) {
int size = (int)Math.Floor(Math.Log(i) / Math.Log(10));
if (i % 100 != 0) {
size += 2;
}
if (i % 10 != 0) {
size++;
}
if (i < 100) {
size++;
if (i < 10) {
size++;
}
}
size--;
byte[] cache = new byte[size];
size --;
if (i < 100) {
cache[0] = (byte)'0';
}
if (i % 10 != 0) {
cache[size--] = bytes[i % 10];
}
if (i % 100 != 0) {
cache[size--] = bytes[(i / 10) % 10];
cache[size--] = (byte)'.';
}
size = (int)Math.Floor(Math.Log(i) / Math.Log(10)) - 1;
int add = 0;
while (add < size) {
cache[add] = bytes[(i / (int)Math.Pow(10, size - add + 1)) % 10];
add++;
}
return cache;
}
/**
* Appends an int. The size of the array will grow by one.
* @param b the int to be appended
* @return a reference to this ByteBuffer object
*/
public ByteBuffer Append_i(int b) {
int newcount = count + 1;
if (newcount > buf.Length) {
byte[] newbuf = new byte[Math.Max(buf.Length << 1, newcount)];
Array.Copy(buf, 0, newbuf, 0, count);
buf = newbuf;
}
buf[count] = (byte)b;
count = newcount;
return this;
}
/**
* Appends the subarray of the byte array. The buffer will grow by
* len bytes.
* @param b the array to be appended
* @param off the offset to the start of the array
* @param len the length of bytes to Append
* @return a reference to this ByteBuffer object
*/
public ByteBuffer Append(byte[] b, int off, int len) {
if ((off < 0) || (off > b.Length) || (len < 0) ||
((off + len) > b.Length) || ((off + len) < 0) || len == 0)
return this;
int newcount = count + len;
if (newcount > buf.Length) {
byte[] newbuf = new byte[Math.Max(buf.Length << 1, newcount)];
Array.Copy(buf, 0, newbuf, 0, count);
buf = newbuf;
}
Array.Copy(b, off, buf, count, len);
count = newcount;
return this;
}
/**
* Appends an array of bytes.
* @param b the array to be appended
* @return a reference to this ByteBuffer object
*/
public ByteBuffer Append(byte[] b) {
return Append(b, 0, b.Length);
}
/**
* Appends a string to the buffer. The string is
* converted according to the encoding ISO-8859-1.
* @param str the string to be appended
* @return a reference to this ByteBuffer object
*/
public ByteBuffer Append(string str) {
if (str != null)
return Append(DocWriter.GetISOBytes(str));
return this;
}
/**
* Appends a char to the buffer. The char is
* converted according to the encoding ISO-8859-1.
* @param c the char to be appended
* @return a reference to this ByteBuffer object
*/
public ByteBuffer Append(char c) {
return Append_i(c);
}
/**
* Appends another ByteBuffer to this buffer.
* @param buf the ByteBuffer to be appended
* @return a reference to this ByteBuffer object
*/
public ByteBuffer Append(ByteBuffer buf) {
return Append(buf.buf, 0, buf.count);
}
/**
* Appends the string representation of an int.
* @param i the int to be appended
* @return a reference to this ByteBuffer object
*/
public ByteBuffer Append(int i) {
return Append((double)i);
}
public ByteBuffer Append(byte b) {
return Append_i(b);
}
public ByteBuffer AppendHex(byte b) {
Append(bytes[(b >> 4) & 0x0f]);
return Append(bytes[b & 0x0f]);
}
/**
* Appends a string representation of a float according
* to the Pdf conventions.
* @param i the float to be appended
* @return a reference to this ByteBuffer object
*/
public ByteBuffer Append(float i) {
return Append((double)i);
}
/**
* Appends a string representation of a double according
* to the Pdf conventions.
* @param d the double to be appended
* @return a reference to this ByteBuffer object
*/
public ByteBuffer Append(double d) {
Append(FormatDouble(d, this));
return this;
}
/**
* Outputs a double into a format suitable for the PDF.
* @param d a double
* @return the string representation of the double
*/
public static string FormatDouble(double d) {
return FormatDouble(d, null);
}
/**
* Outputs a double into a format suitable for the PDF.
* @param d a double
* @param buf a ByteBuffer
* @return the String representation of the double if
* buf is null. If buf is not null,
* then the double is appended directly to the buffer and this methods returns null.
*/
public static string FormatDouble(double d, ByteBuffer buf) {
if (HIGH_PRECISION) {
String sform = d.ToString("0.######", CultureInfo.InvariantCulture);
if (buf == null)
return sform;
else {
buf.Append(sform);
return null;
}
}
bool negative = false;
if (Math.Abs(d) < 0.000015) {
if (buf != null) {
buf.Append(ZERO);
return null;
} else {
return "0";
}
}
if (d < 0) {
negative = true;
d = -d;
}
if (d < 1.0) {
d += 0.000005;
if (d >= 1) {
if (negative) {
if (buf != null) {
buf.Append((byte)'-');
buf.Append((byte)'1');
return null;
} else {
return "-1";
}
} else {
if (buf != null) {
buf.Append((byte)'1');
return null;
} else {
return "1";
}
}
}
if (buf != null) {
int v = (int) (d * 100000);
if (negative) buf.Append((byte)'-');
buf.Append((byte)'0');
buf.Append((byte)'.');
buf.Append( (byte)(v / 10000 + ZERO) );
if (v % 10000 != 0) {
buf.Append( (byte)((v / 1000) % 10 + ZERO) );
if (v % 1000 != 0) {
buf.Append( (byte)((v / 100) % 10 + ZERO) );
if (v % 100 != 0) {
buf.Append((byte)((v / 10) % 10 + ZERO) );
if (v % 10 != 0) {
buf.Append((byte)((v) % 10 + ZERO) );
}
}
}
}
return null;
} else {
int x = 100000;
int v = (int) (d * x);
StringBuilder res = new StringBuilder();
if (negative) res.Append('-');
res.Append("0.");
while ( v < x/10 ) {
res.Append('0');
x /= 10;
}
res.Append(v);
int cut = res.Length - 1;
while (res[cut] == '0') {
--cut;
}
res.Length = cut + 1;
return res.ToString();
}
} else if (d <= 32767) {
d += 0.005;
int v = (int) (d * 100);
if (v < byteCacheSize && byteCache[v] != null) {
if (buf != null) {
if (negative) buf.Append((byte)'-');
buf.Append(byteCache[v]);
return null;
} else {
string tmp = PdfEncodings.ConvertToString(byteCache[v], null);
if (negative) tmp = "-" + tmp;
return tmp;
}
}
if (buf != null) {
if (v < byteCacheSize) {
//create the cachebyte[]
byte[] cache;
int size = 0;
if (v >= 1000000) {
//the original number is >=10000, we need 5 more bytes
size += 5;
} else if (v >= 100000) {
//the original number is >=1000, we need 4 more bytes
size += 4;
} else if (v >= 10000) {
//the original number is >=100, we need 3 more bytes
size += 3;
} else if (v >= 1000) {
//the original number is >=10, we need 2 more bytes
size += 2;
} else if (v >= 100) {
//the original number is >=1, we need 1 more bytes
size += 1;
}
//now we must check if we have a decimal number
if (v % 100 != 0) {
//yes, do not forget the "."
size += 2;
}
if (v % 10 != 0) {
size++;
}
cache = new byte[size];
int add = 0;
if (v >= 1000000) {
cache[add++] = bytes[(v / 1000000)];
}
if (v >= 100000) {
cache[add++] = bytes[(v / 100000) % 10];
}
if (v >= 10000) {
cache[add++] = bytes[(v / 10000) % 10];
}
if (v >= 1000) {
cache[add++] = bytes[(v / 1000) % 10];
}
if (v >= 100) {
cache[add++] = bytes[(v / 100) % 10];
}
if (v % 100 != 0) {
cache[add++] = (byte)'.';
cache[add++] = bytes[(v / 10) % 10];
if (v % 10 != 0) {
cache[add++] = bytes[v % 10];
}
}
byteCache[v] = cache;
}
if (negative) buf.Append((byte)'-');
if (v >= 1000000) {
buf.Append( bytes[(v / 1000000)] );
}
if (v >= 100000) {
buf.Append( bytes[(v / 100000) % 10] );
}
if (v >= 10000) {
buf.Append( bytes[(v / 10000) % 10] );
}
if (v >= 1000) {
buf.Append( bytes[(v / 1000) % 10] );
}
if (v >= 100) {
buf.Append( bytes[(v / 100) % 10] );
}
if (v % 100 != 0) {
buf.Append((byte)'.');
buf.Append( bytes[(v / 10) % 10] );
if (v % 10 != 0) {
buf.Append( bytes[v % 10] );
}
}
return null;
} else {
StringBuilder res = new StringBuilder();
if (negative) res.Append('-');
if (v >= 1000000) {
res.Append( chars[(v / 1000000)] );
}
if (v >= 100000) {
res.Append( chars[(v / 100000) % 10] );
}
if (v >= 10000) {
res.Append( chars[(v / 10000) % 10] );
}
if (v >= 1000) {
res.Append( chars[(v / 1000) % 10] );
}
if (v >= 100) {
res.Append( chars[(v / 100) % 10] );
}
if (v % 100 != 0) {
res.Append('.');
res.Append( chars[(v / 10) % 10] );
if (v % 10 != 0) {
res.Append( chars[v % 10] );
}
}
return res.ToString();
}
} else {
StringBuilder res = new StringBuilder();
if (negative) res.Append('-');
d += 0.5;
long v = (long) d;
return res.Append(v).ToString();
}
}
/**
* Sets the size to zero.
*/
public void Reset() {
count = 0;
}
/**
* Creates a newly allocated byte array. Its size is the current
* size of this output stream and the valid contents of the buffer
* have been copied into it.
*
* @return the current contents of this output stream, as a byte array.
*/
public byte[] ToByteArray() {
byte[] newbuf = new byte[count];
Array.Copy(buf, 0, newbuf, 0, count);
return newbuf;
}
/**
* Returns the current size of the buffer.
*
* @return the value of the count field, which is the number of valid bytes in this byte buffer.
*/
public int Size {
get {
return count;
}
set {
if (value > count || value < 0)
throw new ArgumentOutOfRangeException("The new size must be positive and <= of the current size");
count = value;
}
}
/**
* Converts the buffer's contents into a string, translating bytes into
* characters according to the platform's default character encoding.
*
* @return string translated from the buffer's contents.
*/
public override string ToString() {
char[] tmp = this.ConvertToChar(buf);
return new String(tmp, 0, count);
}
/**
* Converts the buffer's contents into a string, translating bytes into
* characters according to the specified character encoding.
*
* @param enc a character-encoding name.
* @return string translated from the buffer's contents.
* @throws UnsupportedEncodingException
* If the named encoding is not supported.
*/
// public string ToString(System.Text.Encoding enc) {
// return new String(ref buf, 0, count, enc);
// }
/**
* Writes the complete contents of this byte buffer output to
* the specified output stream argument, as if by calling the output
* stream's write method using out.Write(buf, 0, count).
*
* @param out the output stream to which to write the data.
* @exception IOException if an I/O error occurs.
*/
public void WriteTo(Stream str) {
str.Write(buf, 0, count);
}
private char[] ConvertToChar(byte[] buf) {
char[] retVal = new char[count + 1];
for (int i = 0; i <= count; i++) {
retVal[i] = (char)buf[i];
}
return retVal;
}
public byte[] Buffer {
get {
return buf;
}
}
public override bool CanRead {
get {
return false;
}
}
public override bool CanSeek {
get {
return false;
}
}
public override bool CanWrite {
get {
return true;
}
}
public override long Length {
get {
return count;
}
}
public override long Position {
get {
return count;
}
set {
}
}
public override void Flush() {
}
public override int Read(byte[] buffer, int offset, int count) {
return 0;
}
public override long Seek(long offset, SeekOrigin origin) {
return 0;
}
public override void SetLength(long value) {
}
public override void Write(byte[] buffer, int offset, int count) {
Append(buffer, offset, count);
}
public override void WriteByte(byte value) {
Append(value);
}
}
}