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https://github.com/alibaba/druid.git
synced 2023-03-04 19:17:16 +00:00
improved parser performance.
This commit is contained in:
wenshao
@@ -152,10 +152,108 @@ public class StringUtils {
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}
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public static boolean isNumber(String str) {
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if (isEmpty(str)) {
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if (str.length() == 0) {
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return false;
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}
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int sz = str.length();
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boolean hasExp = false;
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boolean hasDecPoint = false;
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boolean allowSigns = false;
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boolean foundDigit = false;
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// deal with any possible sign up front
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int start = (str.charAt(0) == '-') ? 1 : 0;
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if (sz > start + 1) {
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if (str.charAt(start) == '0' && str.charAt(start + 1) == 'x') {
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int i = start + 2;
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if (i == sz) {
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return false; // str == "0x"
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}
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// checking hex (it can't be anything else)
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for (; i < str.length(); i++) {
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char ch = str.charAt(i);
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if ((ch < '0' || ch > '9')
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&& (ch < 'a' || ch > 'f')
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&& (ch < 'A' || ch > 'F')) {
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return false;
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}
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}
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return true;
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}
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}
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sz--; // don't want to loop to the last char, check it afterwords
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// for type qualifiers
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int i = start;
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// loop to the next to last char or to the last char if we need another digit to
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// make a valid number (e.g. chars[0..5] = "1234E")
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while (i < sz || (i < sz + 1 && allowSigns && !foundDigit)) {
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char ch = str.charAt(i);
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if (ch >= '0' && ch <= '9') {
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foundDigit = true;
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allowSigns = false;
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} else if (ch == '.') {
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if (hasDecPoint || hasExp) {
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// two decimal points or dec in exponent
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return false;
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}
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hasDecPoint = true;
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} else if (ch == 'e' || ch == 'E') {
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// we've already taken care of hex.
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if (hasExp) {
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// two E's
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return false;
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}
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if (!foundDigit) {
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return false;
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}
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hasExp = true;
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allowSigns = true;
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} else if (ch == '+' || ch == '-') {
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if (!allowSigns) {
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return false;
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}
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allowSigns = false;
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foundDigit = false; // we need a digit after the E
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} else {
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return false;
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}
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i++;
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}
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if (i < str.length()) {
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char ch = str.charAt(i);
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if (ch >= '0' && ch <= '9') {
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// no type qualifier, OK
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return true;
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}
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if (ch == 'e' || ch == 'E') {
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// can't have an E at the last byte
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return false;
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}
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if (!allowSigns
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&& (ch == 'd'
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|| ch == 'D'
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|| ch == 'f'
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|| ch == 'F')) {
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return foundDigit;
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}
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if (ch == 'l'
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|| ch == 'L') {
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// not allowing L with an exponent
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return foundDigit && !hasExp;
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}
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// last character is illegal
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return false;
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}
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// allowSigns is true iff the val ends in 'E'
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// found digit it to make sure weird stuff like '.' and '1E-' doesn't pass
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return !allowSigns && foundDigit;
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}
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public static boolean isNumber(char[] chars) {
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if (chars.length == 0) {
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return false;
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}
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char[] chars = str.toCharArray();
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int sz = chars.length;
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boolean hasExp = false;
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boolean hasDecPoint = false;
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@@ -171,9 +269,10 @@ public class StringUtils {
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}
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// checking hex (it can't be anything else)
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for (; i < chars.length; i++) {
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if ((chars[i] < '0' || chars[i] > '9')
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&& (chars[i] < 'a' || chars[i] > 'f')
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&& (chars[i] < 'A' || chars[i] > 'F')) {
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char ch = chars[i];
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if ((ch < '0' || ch > '9')
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&& (ch < 'a' || ch > 'f')
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&& (ch < 'A' || ch > 'F')) {
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return false;
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}
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}
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@@ -186,17 +285,18 @@ public class StringUtils {
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// loop to the next to last char or to the last char if we need another digit to
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// make a valid number (e.g. chars[0..5] = "1234E")
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while (i < sz || (i < sz + 1 && allowSigns && !foundDigit)) {
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if (chars[i] >= '0' && chars[i] <= '9') {
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char ch = chars[i];
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if (ch >= '0' && ch <= '9') {
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foundDigit = true;
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allowSigns = false;
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} else if (chars[i] == '.') {
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} else if (ch == '.') {
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if (hasDecPoint || hasExp) {
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// two decimal points or dec in exponent
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return false;
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}
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hasDecPoint = true;
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} else if (chars[i] == 'e' || chars[i] == 'E') {
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} else if (ch == 'e' || ch == 'E') {
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// we've already taken care of hex.
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if (hasExp) {
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// two E's
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@@ -207,7 +307,7 @@ public class StringUtils {
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}
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hasExp = true;
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allowSigns = true;
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} else if (chars[i] == '+' || chars[i] == '-') {
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} else if (ch == '+' || ch == '-') {
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if (!allowSigns) {
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return false;
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}
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@@ -219,23 +319,24 @@ public class StringUtils {
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i++;
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}
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if (i < chars.length) {
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if (chars[i] >= '0' && chars[i] <= '9') {
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char ch = chars[i];
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if (ch >= '0' && ch <= '9') {
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// no type qualifier, OK
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return true;
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}
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if (chars[i] == 'e' || chars[i] == 'E') {
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if (ch == 'e' || ch == 'E') {
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// can't have an E at the last byte
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return false;
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}
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if (!allowSigns
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&& (chars[i] == 'd'
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|| chars[i] == 'D'
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|| chars[i] == 'f'
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|| chars[i] == 'F')) {
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&& (ch == 'd'
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|| ch == 'D'
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|| ch == 'f'
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|| ch == 'F')) {
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return foundDigit;
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}
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if (chars[i] == 'l'
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|| chars[i] == 'L') {
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if (ch == 'l'
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|| ch == 'L') {
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// not allowing L with an exponent
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return foundDigit && !hasExp;
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}
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