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package org.codehaus.jackson.io;
public final class NumberInput
{
/**
* Constants needed for parsing longs from basic int parsing methods
*/
final static long L_BILLION = 1000000000;
final static String MIN_LONG_STR_NO_SIGN = String.valueOf(Long.MIN_VALUE).substring(1);
final static String MAX_LONG_STR = String.valueOf(Long.MAX_VALUE);
/**
* Fast method for parsing integers that are known to fit into
* regular 32-bit signed int type. This means that length is
* between 1 and 9 digits (inclusive)
*
* Note: public to let unit tests call it
*/
public final static int parseInt(char[] digitChars, int offset, int len)
{
int num = digitChars[offset] - '0';
len += offset;
// This looks ugly, but appears the fastest way:
if (++offset < len) {
num = (num * 10) + (digitChars[offset] - '0');
if (++offset < len) {
num = (num * 10) + (digitChars[offset] - '0');
if (++offset < len) {
num = (num * 10) + (digitChars[offset] - '0');
if (++offset < len) {
num = (num * 10) + (digitChars[offset] - '0');
if (++offset < len) {
num = (num * 10) + (digitChars[offset] - '0');
if (++offset < len) {
num = (num * 10) + (digitChars[offset] - '0');
if (++offset < len) {
num = (num * 10) + (digitChars[offset] - '0');
if (++offset < len) {
num = (num * 10) + (digitChars[offset] - '0');
}
}
}
}
}
}
}
}
return num;
}
public final static long parseLong(char[] digitChars, int offset, int len)
{
// Note: caller must ensure length is [10, 18]
int len1 = len-9;
long val = parseInt(digitChars, offset, len1) * L_BILLION;
return val + (long) parseInt(digitChars, offset+len1, 9);
}
/**
* Helper method for determining if given String representation of
* an integral number would fit in 64-bit Java long or not.
* Note that input String must NOT contain leading minus sign (even
* if 'negative' is set to true).
*
* @param negative Whether original number had a minus sign (which is
* NOT passed to this method) or not
*/
public final static boolean inLongRange(char[] digitChars, int offset, int len,
boolean negative)
{
String cmpStr = negative ? MIN_LONG_STR_NO_SIGN : MAX_LONG_STR;
int cmpLen = cmpStr.length();
if (len < cmpLen) return true;
if (len > cmpLen) return false;
for (int i = 0; i < cmpLen; ++i) {
if (digitChars[offset+i] > cmpStr.charAt(i)) {
return false;
}
}
return true;
}
/**
* Similar to {@link #inLongRange(char[],int,int,boolean)}, but
* with String argument
*
* @param negative Whether original number had a minus sign (which is
* NOT passed to this method) or not
*
* @since 1.5.0
*/
public final static boolean inLongRange(String numberStr, boolean negative)
{
String cmpStr = negative ? MIN_LONG_STR_NO_SIGN : MAX_LONG_STR;
int cmpLen = cmpStr.length();
int actualLen = numberStr.length();
if (actualLen < cmpLen) return true;
if (actualLen > cmpLen) return false;
// could perhaps just use String.compareTo()?
for (int i = 0; i < cmpLen; ++i) {
if (numberStr.charAt(i) > cmpStr.charAt(i)) {
return false;
}
}
return true;
}
}