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// file:
//
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// modification, are permitted provided that the following conditions are
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package jdk.nashorn.internal.runtime.doubleconv;
/**
* A buffer for generating string representations of doubles.
*/
public class DtoaBuffer {
// The character buffer
final char[] chars;
// The number of characters in the buffer
int length = 0;
// The position of the decimal point
int decimalPoint = 0;
// Is this a negative number?
boolean isNegative = false;
/**
* Maximal length of numbers converted by FastDtoa
*/
public static final int kFastDtoaMaximalLength = FastDtoa.kFastDtoaMaximalLength;
/**
* Create a buffer with the given capacity.
* @param capacity the capacity of the buffer.
*/
public DtoaBuffer(final int capacity) {
chars = new char[capacity];
}
/**
* Append a character to the buffer, increasing its length.
* @param c character
*/
void append(final char c) {
chars[length++] = c;
}
/**
* Clear the buffer contents and set its length to {@code 0}.
*/
public void reset() {
length = 0;
decimalPoint = 0;
}
/**
* Get the raw digits of this buffer as string.
* @return the raw buffer contents
*/
public String getRawDigits() {
return new String(chars, 0, length);
}
/**
* Get the position of the decimal point.
* @return the decimal point position
*/
public int getDecimalPoint() {
return decimalPoint;
}
/**
* Returns the number of characters in the buffer.
* @return buffer length
*/
public int getLength() {
return length;
}
/**
* Returns the formatted buffer content as string, using the specified conversion mode
* and padding.
*
* @param mode conversion mode
* @param digitsAfterPoint number of digits after point
* @return formatted string
*/
public String format(final DtoaMode mode, final int digitsAfterPoint) {
final StringBuilder buffer = new StringBuilder();
if (isNegative) {
buffer.append('-');
}
// check for minus sign
switch (mode) {
case SHORTEST:
if (decimalPoint < -5 || decimalPoint > 21) {
toExponentialFormat(buffer);
} else {
toFixedFormat(buffer, digitsAfterPoint);
}
break;
case FIXED:
toFixedFormat(buffer, digitsAfterPoint);
break;
case PRECISION:
if (decimalPoint < -5 || decimalPoint > length) {
toExponentialFormat(buffer);
} else {
toFixedFormat(buffer, digitsAfterPoint);
}
break;
}
return buffer.toString();
}
private void toFixedFormat(final StringBuilder buffer, final int digitsAfterPoint) {
if (decimalPoint <= 0) {
// < 1,
buffer.append('0');
if (length > 0) {
buffer.append('.');
final int padding = -decimalPoint;
for (int i = 0; i < padding; i++) {
buffer.append('0');
}
buffer.append(chars, 0, length);
} else {
decimalPoint = 1;
}
} else if (decimalPoint >= length) {
// large integer, add trailing zeroes
buffer.append(chars, 0, length);
for (int i = length; i < decimalPoint; i++) {
buffer.append('0');
}
} else if (decimalPoint < length) {
// >= 1, split decimals and insert decimalPoint
buffer.append(chars, 0, decimalPoint);
buffer.append('.');
buffer.append(chars, decimalPoint, length - decimalPoint);
}
// Create trailing zeros if requested
if (digitsAfterPoint > 0) {
if (decimalPoint >= length) {
buffer.append('.');
}
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