NumberInput.java
package com.fasterxml.jackson.core.io;
import ch.randelshofer.fastdoubleparser.JavaDoubleParser;
import ch.randelshofer.fastdoubleparser.JavaFloatParser;
import java.math.BigDecimal;
import java.math.BigInteger;
/**
* Helper class for efficient parsing of various JSON numbers.
*<p>
* NOTE! Does NOT validate against maximum length limits: caller must
* do that if and as necessary.
*/
public final class NumberInput
{
/**
* Formerly used constant for a value that was problematic on certain
* pre-1.8 JDKs.
*
* @deprecated Since 2.14 -- do not use
*/
@Deprecated // since 2.14
public final static String NASTY_SMALL_DOUBLE = "2.2250738585072012e-308";
/**
* 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 unsigned integers that are known to fit into
* regular 32-bit signed int type. This means that length is
* between 1 and 9 digits (inclusive) and there is no sign character.
*<p>
* Note: public to let unit tests call it; not meant to be used by any
* code outside this package.
*
* @param ch Buffer that contains integer value to decode
* @param off Offset of the first digit character in buffer
* @param len Length of the number to decode (in characters)
*
* @return Decoded {@code int} value
*/
public static int parseInt(char[] ch, int off, int len)
{
if (len > 0 && ch[off] == '+') {
off++;
len--;
}
int num = ch[off + len - 1] - '0';
switch(len) {
case 9:
num += (ch[off++] - '0') * 100000000;
case 8:
num += (ch[off++] - '0') * 10000000;
case 7:
num += (ch[off++] - '0') * 1000000;
case 6:
num += (ch[off++] - '0') * 100000;
case 5:
num += (ch[off++] - '0') * 10000;
case 4:
num += (ch[off++] - '0') * 1000;
case 3:
num += (ch[off++] - '0') * 100;
case 2:
num += (ch[off] - '0') * 10;
}
return num;
}
/**
* Helper method to (more) efficiently parse integer numbers from
* String values. Input String must be simple Java integer value.
* No range checks are made to verify that the value fits in 32-bit Java {@code int}:
* caller is expected to only calls this in cases where this can be guaranteed
* (basically: number of digits does not exceed 9)
*<p>
* NOTE: semantics differ significantly from {@link #parseInt(char[], int, int)}.
*
* @param s String that contains integer value to decode
*
* @return Decoded {@code int} value
*/
public static int parseInt(String s)
{
/* Ok: let's keep strategy simple: ignoring optional minus sign,
* we'll accept 1 - 9 digits and parse things efficiently;
* otherwise just defer to JDK parse functionality.
*/
char c = s.charAt(0);
int len = s.length();
boolean neg = (c == '-');
int offset = 1;
// must have 1 - 9 digits after optional sign:
// negative?
if (neg) {
if (len == 1 || len > 10) {
return Integer.parseInt(s);
}
c = s.charAt(offset++);
} else {
if (len > 9) {
return Integer.parseInt(s);
}
}
if (c > '9' || c < '0') {
return Integer.parseInt(s);
}
int num = c - '0';
if (offset < len) {
c = s.charAt(offset++);
if (c > '9' || c < '0') {
return Integer.parseInt(s);
}
num = (num * 10) + (c - '0');
if (offset < len) {
c = s.charAt(offset++);
if (c > '9' || c < '0') {
return Integer.parseInt(s);
}
num = (num * 10) + (c - '0');
// Let's just loop if we have more than 3 digits:
if (offset < len) {
do {
c = s.charAt(offset++);
if (c > '9' || c < '0') {
return Integer.parseInt(s);
}
num = (num * 10) + (c - '0');
} while (offset < len);
}
}
}
return neg ? -num : num;
}
public static long parseLong(char[] ch, int off, int len)
{
// Note: caller must ensure length is [10, 18]
int len1 = len-9;
long val = parseInt(ch, off, len1) * L_BILLION;
return val + (long) parseInt(ch, off+len1, 9);
}
/**
* Parses an unsigned long made up of exactly 19 digits.
* <p>
* It is the callers responsibility to make sure the input is exactly 19 digits.
* and fits into a 64bit long by calling {@link #inLongRange(char[], int, int, boolean)}
* first.
* <p>
* Note that input String must NOT contain leading minus sign (even
* if {@code negative} is set to true).
*
* @param ch Buffer that contains integer value to decode
* @param off Offset of the first digit character in buffer
* @param negative Whether original number had a minus sign
* @return Decoded {@code long} value
*
* @since 2.15.0
*/
public static long parseLong19(char[] ch, int off, boolean negative)
{
// Note: caller must ensure length is 19
long num = 0L;
for (int i = 0; i < 19; i++) {
char c = ch[off + i];
num = (num * 10) + (c - '0');
}
return negative ? -num : num;
}
/**
* Similar to {@link #parseInt(String)} but for {@code long} values.
*
* @param s String that contains {@code long} value to decode
*
* @return Decoded {@code long} value
*/
public static long parseLong(String s)
{
// Ok, now; as the very first thing, let's just optimize case of "fake longs";
// that is, if we know they must be ints, call int parsing
int length = s.length();
if (length <= 9) {
return (long) parseInt(s);
}
// !!! TODO: implement efficient 2-int parsing...
return Long.parseLong(s);
}
/**
* 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 ch Buffer that contains long value to check
* @param off Offset of the first digit character in buffer
* @param len Length of the number to decode (in characters)
* @param negative Whether original number had a minus sign (which is
* NOT passed to this method) or not
*
* @return {@code True} if specified String representation is within Java
* {@code long} range; {@code false} if not.
*/
public static boolean inLongRange(char[] ch, int off, 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) {
int diff = ch[off+i] - cmpStr.charAt(i);
if (diff != 0) {
return (diff < 0);
}
}
return true;
}
/**
* Similar to {@link #inLongRange(char[],int,int,boolean)}, but
* with String argument
*
* @param s String that contains {@code long} value to check
* @param negative Whether original number had a minus sign (which is
* NOT passed to this method) or not
*
* @return {@code True} if specified String representation is within Java
* {@code long} range; {@code false} if not.
*/
public static boolean inLongRange(String s, boolean negative)
{
String cmp = negative ? MIN_LONG_STR_NO_SIGN : MAX_LONG_STR;
int cmpLen = cmp.length();
int alen = s.length();
if (alen < cmpLen) return true;
if (alen > cmpLen) return false;
// could perhaps just use String.compareTo()?
for (int i = 0; i < cmpLen; ++i) {
int diff = s.charAt(i) - cmp.charAt(i);
if (diff != 0) {
return (diff < 0);
}
}
return true;
}
public static int parseAsInt(String s, int def)
{
if (s == null) {
return def;
}
s = s.trim();
int len = s.length();
if (len == 0) {
return def;
}
// One more thing: use integer parsing for 'simple'
int i = 0;
// skip leading sign, if any
final char sign = s.charAt(0);
if (sign == '+') { // for plus, actually physically remove
s = s.substring(1);
len = s.length();
} else if (sign == '-') { // minus, just skip for checks, must retain
i = 1;
}
for (; i < len; ++i) {
char c = s.charAt(i);
// if other symbols, parse as Double, coerce
if (c > '9' || c < '0') {
try {
//useFastParser=true is used because there is a lot less risk that small changes in result will have an affect
//and performance benefit is useful
return (int) parseDouble(s, true);
} catch (NumberFormatException e) {
return def;
}
}
}
try {
return Integer.parseInt(s);
} catch (NumberFormatException e) { }
return def;
}
public static long parseAsLong(String s, long def)
{
if (s == null) {
return def;
}
s = s.trim();
int len = s.length();
if (len == 0) {
return def;
}
// One more thing: use long parsing for 'simple'
int i = 0;
// skip leading sign, if any
final char sign = s.charAt(0);
if (sign == '+') { // for plus, actually physically remove
s = s.substring(1);
len = s.length();
} else if (sign == '-') { // minus, just skip for checks, must retain
i = 1;
}
for (; i < len; ++i) {
char c = s.charAt(i);
// if other symbols, parse as Double, coerce
if (c > '9' || c < '0') {
try {
//useFastParser=true is used because there is a lot less risk that small changes in result will have an affect
//and performance benefit is useful
return (long) parseDouble(s, true);
} catch (NumberFormatException e) {
return def;
}
}
}
try {
return Long.parseLong(s);
} catch (NumberFormatException e) { }
return def;
}
/**
* @param s a string representing a number to parse
* @param def the default to return if `s` is not a parseable number
* @return closest matching double (or `def` if there is an issue with `s`) where useFastParser=false
* @see #parseAsDouble(String, double, boolean)
*/
public static double parseAsDouble(final String s, final double def)
{
return parseAsDouble(s, def, false);
}
/**
* @param s a string representing a number to parse
* @param def the default to return if `s` is not a parseable number
* @param useFastParser whether to use {@code FastDoubleParser}
* @return closest matching double (or `def` if there is an issue with `s`)
* @since 2.14
*/
public static double parseAsDouble(String s, final double def, final boolean useFastParser)
{
if (s == null) { return def; }
s = s.trim();
int len = s.length();
if (len == 0) {
return def;
}
try {
return parseDouble(s, useFastParser);
} catch (NumberFormatException e) { }
return def;
}
/**
* @param s a string representing a number to parse
* @return closest matching double
* @throws NumberFormatException if string cannot be represented by a double where useFastParser=false
* @see #parseDouble(String, boolean)
*/
public static double parseDouble(final String s) throws NumberFormatException {
return parseDouble(s, false);
}
/**
* @param s a string representing a number to parse
* @param useFastParser whether to use {@code FastDoubleParser}
* @return closest matching double
* @throws NumberFormatException if string cannot be represented by a double
* @since v2.14
*/
public static double parseDouble(final String s, final boolean useFastParser) throws NumberFormatException {
return useFastParser ? JavaDoubleParser.parseDouble(s) : Double.parseDouble(s);
}
/**
* @param s a string representing a number to parse
* @return closest matching float
* @throws NumberFormatException if string cannot be represented by a float where useFastParser=false
* @see #parseFloat(String, boolean)
* @since v2.14
*/
public static float parseFloat(final String s) throws NumberFormatException {
return parseFloat(s, false);
}
/**
* @param s a string representing a number to parse
* @param useFastParser whether to use {@code FastDoubleParser}
* @return closest matching float
* @throws NumberFormatException if string cannot be represented by a float
* @since v2.14
*/
public static float parseFloat(final String s, final boolean useFastParser) throws NumberFormatException {
return useFastParser ? JavaFloatParser.parseFloat(s) : Float.parseFloat(s);
}
/**
* @param s a string representing a number to parse
* @return a BigDecimal
* @throws NumberFormatException if the char array cannot be represented by a BigDecimal
*/
public static BigDecimal parseBigDecimal(final String s) throws NumberFormatException {
return BigDecimalParser.parse(s);
}
/**
* @param s a string representing a number to parse
* @param useFastParser whether to use custom fast parser (true) or JDK default (false) parser
* @return a BigDecimal
* @throws NumberFormatException if the char array cannot be represented by a BigDecimal
* @since v2.15
*/
public static BigDecimal parseBigDecimal(final String s, final boolean useFastParser) throws NumberFormatException {
return useFastParser ?
BigDecimalParser.parseWithFastParser(s) :
BigDecimalParser.parse(s);
}
/**
* @param ch a char array with text that makes up a number
* @param off the offset to apply when parsing the number in the char array
* @param len the length of the number in the char array
* @return a BigDecimal
* @throws NumberFormatException if the char array cannot be represented by a BigDecimal
*/
public static BigDecimal parseBigDecimal(final char[] ch, final int off, final int len) throws NumberFormatException {
return BigDecimalParser.parse(ch, off, len);
}
/**
* @param ch a char array with text that makes up a number
* @param off the offset to apply when parsing the number in the char array
* @param len the length of the number in the char array
* @param useFastParser whether to use custom fast parser (true) or JDK default (false) parser
* @return a BigDecimal
* @throws NumberFormatException if the char array cannot be represented by a BigDecimal
* @since v2.15
*/
public static BigDecimal parseBigDecimal(final char[] ch, final int off, final int len,
final boolean useFastParser)
throws NumberFormatException {
return useFastParser ?
BigDecimalParser.parseWithFastParser(ch, off, len) :
BigDecimalParser.parse(ch, off, len);
}
/**
* @param ch a char array with text that makes up a number
* @return a BigDecimal
* @throws NumberFormatException if the char array cannot be represented by a BigDecimal
*/
public static BigDecimal parseBigDecimal(final char[] ch) throws NumberFormatException {
return BigDecimalParser.parse(ch);
}
/**
* @param ch a char array with text that makes up a number
* @param useFastParser whether to use custom fast parser (true) or JDK default (false) parser
* @return a BigDecimal
* @throws NumberFormatException if the char array cannot be represented by a BigDecimal
* @since v2.15
*/
public static BigDecimal parseBigDecimal(final char[] ch, final boolean useFastParser) throws NumberFormatException {
return useFastParser ?
BigDecimalParser.parseWithFastParser(ch, 0, ch.length) :
BigDecimalParser.parse(ch);
}
/**
* @param s a string representing a number to parse
* @return a BigInteger
* @throws NumberFormatException if string cannot be represented by a BigInteger
* @since v2.14
*/
public static BigInteger parseBigInteger(final String s) throws NumberFormatException {
return new BigInteger(s);
}
/**
* @param s a string representing a number to parse
* @param useFastParser whether to use custom fast parser (true) or JDK default (false) parser
* @return a BigInteger
* @throws NumberFormatException if string cannot be represented by a BigInteger
* @since v2.15
*/
public static BigInteger parseBigInteger(final String s, final boolean useFastParser) throws NumberFormatException {
if (useFastParser) {
return BigIntegerParser.parseWithFastParser(s);
} else {
return parseBigInteger(s);
}
}
/**
* @param s a string representing a number to parse
* @param radix for parse
* @param useFastParser whether to use custom fast parser (true) or JDK default (false) parser
* @return a BigInteger
* @throws NumberFormatException if string cannot be represented by a BigInteger
* @since v2.15
*/
public static BigInteger parseBigIntegerWithRadix(final String s, final int radix,
final boolean useFastParser) throws NumberFormatException {
if (useFastParser) {
return BigIntegerParser.parseWithFastParser(s, radix);
} else {
return new BigInteger(s, radix);
}
}
}