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Remove BigInteger from values which probably will never need them lik…
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…e year.

This improves my bench a bit more (BEFORE):

```text
jruby ../snippets/date_bench.rb 
Warming up --------------------------------------
           _strptime    26.267k i/100ms
Calculating -------------------------------------
           _strptime    319.069k (± 5.8%) i/s -      3.178M in   9.998810s
```

AFTER:

```text
jruby  ../snippets/date_bench.rb 
Warming up --------------------------------------
           _strptime    29.320k i/100ms
Calculating -------------------------------------
           _strptime    353.076k (± 2.9%) i/s -      3.548M in  10.057641s
```

I also examined MRIs implementation and they basically do all dyncalls for all
the math which this rewrite in Java does not do.  I think this is ok but it
underlies how much more overhead may be lurking here (since we are doing direct
Java math).

I did not change seconds and smaller units of time since they may exceed long
boundary.  In that case a followup optimization would be to check digits of text
and flip to BigInteger only in those cases otherwise assume long or even int
when it fits.
@enebo
enebo committed Jun 20, 2017
1 parent 65e1495 commit 5825391
Showing 1 changed file with 59 additions and 29 deletions.
88 changes: 59 additions & 29 deletions core/src/main/java/org/jruby/util/StrptimeParser.java
View file
Original file line number Diff line number Diff line change
@@ -40,7 +40,7 @@

/**
* This is Java implementation of ext/date/date_strptime.c in Ruby 2.3.1.
* @see https://github.com/ruby/ruby/blob/394fa89c67722d35bdda89f10c7de5c304a5efb1/ext/date/date_strptime.c
* see https://github.com/ruby/ruby/blob/394fa89c67722d35bdda89f10c7de5c304a5efb1/ext/date/date_strptime.c
*/
public class StrptimeParser {
// day_names
@@ -63,19 +63,19 @@ public class StrptimeParser {

/**
* Ported Date::Format::Bag from lib/ruby/stdlib/date/format.rb in JRuby 9.1.5.0.
* @see https://github.com/jruby/jruby/blob/036ce39f0476d4bd718e23e64caff36bb50b8dbc/lib/ruby/stdlib/date/format.rb
* see https://github.com/jruby/jruby/blob/036ce39f0476d4bd718e23e64caff36bb50b8dbc/lib/ruby/stdlib/date/format.rb
*/
public static class FormatBag {
private int mDay = Integer.MIN_VALUE;
private int wDay = Integer.MIN_VALUE;
private int cWDay = Integer.MIN_VALUE;
private int yDay = Integer.MIN_VALUE;
private int cWeek = Integer.MIN_VALUE;
private BigInteger cWYear = null;
private long cWYear = Long.MIN_VALUE;
private int min = Integer.MIN_VALUE;
private int mon = Integer.MIN_VALUE;
private int hour = Integer.MIN_VALUE;
private BigInteger year = null;
private long year = Long.MIN_VALUE;
private int sec = Integer.MIN_VALUE;
private int wNum0 = Integer.MIN_VALUE;
private int wNum1 = Integer.MIN_VALUE;
@@ -89,7 +89,7 @@ public static class FormatBag {
private int secondsSize = Integer.MIN_VALUE;

private int merid = Integer.MIN_VALUE;
private BigInteger cent = null;
private long cent = Long.MIN_VALUE;

private boolean fail = false;
private String leftover = null;
@@ -114,7 +114,7 @@ public int getCWeek() {
return cWeek;
}

public BigInteger getCWYear() {
public long getCWYear() {
return cWYear;
}

@@ -130,7 +130,7 @@ public int getHour() {
return hour;
}

public BigInteger getYear() {
public long getYear() {
return year;
}

@@ -170,7 +170,7 @@ public int getMerid() {
return merid;
}

public BigInteger getCent() {
public long getCent() {
return cent;
}

@@ -186,6 +186,10 @@ public static boolean has(int v) {
return v != Integer.MIN_VALUE;
}

public static boolean has(long v) {
return v != Long.MIN_VALUE;
}

public static boolean has(BigInteger v) {
return v != null;
}
@@ -199,7 +203,7 @@ public StrptimeParser() {

/**
* Ported from RubyDateFormatter#addToPattern in JRuby 9.1.5.0.
* @see https://github.com/jruby/jruby/blob/036ce39f0476d4bd718e23e64caff36bb50b8dbc/core/src/main/java/org/jruby/util/RubyDateFormatter.java
* see https://github.com/jruby/jruby/blob/036ce39f0476d4bd718e23e64caff36bb50b8dbc/core/src/main/java/org/jruby/util/RubyDateFormatter.java
*/
private void addToPattern(final List<StrptimeToken> compiledPattern, final String str) {
for (int i = 0; i < str.length(); i++) {
@@ -214,7 +218,7 @@ private void addToPattern(final List<StrptimeToken> compiledPattern, final Strin

/**
* Ported from RubyDateFormatter#compilePattern in JRuby 9.1.5.0.
* @see https://github.com/jruby/jruby/blob/036ce39f0476d4bd718e23e64caff36bb50b8dbc/core/src/main/java/org/jruby/util/RubyDateFormatter.java
* see https://github.com/jruby/jruby/blob/036ce39f0476d4bd718e23e64caff36bb50b8dbc/core/src/main/java/org/jruby/util/RubyDateFormatter.java
*/
public List<StrptimeToken> compilePattern(final String pattern) {
final List<StrptimeToken> compiledPattern = new LinkedList<>();
@@ -288,14 +292,14 @@ public FormatBag parse(final List<StrptimeToken> compiledPattern, final String t

if (FormatBag.has(bag.cent)) {
if (FormatBag.has(bag.cWYear)) {
bag.cWYear = bag.cWYear.add(bag.cent.multiply(BigInteger.valueOf(100)));
bag.cWYear += bag.cent * 100;
}
if (FormatBag.has(bag.year)) {
bag.year = bag.year.add(bag.cent.multiply(BigInteger.valueOf(100)));
bag.year += bag.cent * 100;
}

// delete bag._cent
bag.cent = null;
bag.cent = Long.MIN_VALUE;
}

if (FormatBag.has(bag.merid)) {
@@ -378,9 +382,9 @@ private FormatBag parse(final List<StrptimeToken> compiledPattern) {
}
case FORMAT_CENTURY: { // %C - year / 100 (round down. 20 in 2009)
if (isNumberPattern(compiledPattern, tokenIndex)) {
bag.cent = BigInteger.valueOf(readDigits(2));
bag.cent = readDigits(2);
} else {
bag.cent = readDigitsMax();
bag.cent = readDigitsMaxLong();
}
break;
}
@@ -402,9 +406,9 @@ private FormatBag parse(final List<StrptimeToken> compiledPattern) {
}
case FORMAT_WEEKYEAR: { // %G - The week-based year
if (isNumberPattern(compiledPattern, tokenIndex)) {
bag.cWYear = BigInteger.valueOf(readDigits(4));
bag.cWYear = readDigits(4);
} else {
bag.cWYear = readDigitsMax();
bag.cWYear = readDigitsMaxLong();
}
break;
}
@@ -413,9 +417,9 @@ private FormatBag parse(final List<StrptimeToken> compiledPattern) {
if (!validRange(v, 0, 99)) {
fail = true;
}
bag.cWYear = BigInteger.valueOf(v);
bag.cWYear = v;
if (!bag.has(bag.cent)) {
bag.cent = BigInteger.valueOf((int)v >= 69 ? 19 : 20);
bag.cent = v >= 69 ? 19 : 20;
}
break;
}
@@ -588,23 +592,23 @@ private FormatBag parse(final List<StrptimeToken> compiledPattern) {
pos++;
}

final BigInteger year;
final long year;
if (isNumberPattern(compiledPattern, tokenIndex)) {
year = BigInteger.valueOf(readDigits(4));
year = readDigits(4);
} else {
year = readDigitsMax();
year = readDigitsMaxLong();
}
bag.year = !negative ? year : year.negate();
bag.year = !negative ? year : -1 * year;
break;
}
case FORMAT_YEAR_SHORT: { // %y, %Ey, %Oy - year % 100 (00..99)
final long year = readDigits(2);
if (!validRange(year, 0, 99)) {
fail = true;
}
bag.year = BigInteger.valueOf(year);
bag.year = year;
if (!bag.has(bag.cent)) {
bag.cent = BigInteger.valueOf((int)year >= 69 ? 19 : 20);
bag.cent = year >= 69 ? 19 : 20;
}
break;
}
@@ -651,7 +655,7 @@ private FormatBag parse(final List<StrptimeToken> compiledPattern) {

/**
* Ports read_digits from ext/date/date_strptime.c in MRI 2.3.1 under BSDL.
* @see https://github.com/ruby/ruby/blob/394fa89c67722d35bdda89f10c7de5c304a5efb1/ext/date/date_strftime.c
* see https://github.com/ruby/ruby/blob/394fa89c67722d35bdda89f10c7de5c304a5efb1/ext/date/date_strftime.c
*/
private long readDigits(final int len) {
char c;
@@ -681,7 +685,7 @@ private long readDigits(final int len) {

/**
* Ports READ_DIGITS_MAX from ext/date/date_strptime.c in MRI 2.3.1 under BSDL.
* @see https://github.com/ruby/ruby/blob/394fa89c67722d35bdda89f10c7de5c304a5efb1/ext/date/date_strftime.c
* see https://github.com/ruby/ruby/blob/394fa89c67722d35bdda89f10c7de5c304a5efb1/ext/date/date_strftime.c
*/
private BigInteger readDigitsMax() {
char c;
@@ -709,6 +713,32 @@ private BigInteger readDigitsMax() {
return v;
}

private long readDigitsMaxLong() {
char c;
long v = 0L;
final int initPos = pos;

while (true) {
if (isEndOfText(text, pos)) {
break;
}

c = text.charAt(pos);
if (!isDigit(c)) {
break;
} else {
v = v * 10 + toInt(c);
}
pos += 1;
}

if (pos == initPos) {
fail = true;
}

return v;
}

/**
* Returns -1 if text doesn't match with patterns.
*/
@@ -731,7 +761,7 @@ private int findIndexInPatterns(final String[] patterns) {

/**
* Ports num_pattern_p from ext/date/date_strptime.c in MRI 2.3.1 under BSDL.
* @see https://github.com/ruby/ruby/blob/394fa89c67722d35bdda89f10c7de5c304a5efb1/ext/date/date_strftime.c
* see https://github.com/ruby/ruby/blob/394fa89c67722d35bdda89f10c7de5c304a5efb1/ext/date/date_strftime.c
*/
private static boolean isNumberPattern(final List<StrptimeToken> compiledPattern, final int i) {
if (compiledPattern.size() <= i + 1) {
@@ -785,7 +815,7 @@ private static boolean isNumberPattern(final List<StrptimeToken> compiledPattern

/**
* Ports valid_pattern_p in ext/date/date_strptime.c in MRI 2.3.1 under BSDL.
* @see https://github.com/ruby/ruby/blob/394fa89c67722d35bdda89f10c7de5c304a5efb1/ext/date/date_strftime.c
* see https://github.com/ruby/ruby/blob/394fa89c67722d35bdda89f10c7de5c304a5efb1/ext/date/date_strftime.c
*/
private static boolean validRange(long v, int lower, int upper) {
return lower <= v && v <= upper;

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