Add support for "week of month" in SimpleDateTimeFormatter

velox/functions/lib/DateTimeFormatter.cpp

@@ -47,10 +47,14 @@ struct Date {
   int32_t dayOfYear = 1;
   bool dayOfYearFormat = false;
 
+  int32_t weekOfMonth = 1;
+  bool weekOfMonthDateFormat = false;
+
   bool centuryFormat = false;
 
   bool isYearOfEra = false; // Year of era cannot be zero or negative.
   bool hasYear = false; // Whether year was explicitly specified.
+  bool hasDayOfWeek = false; // Whether dayOfWeek was explicitly specified.
 
   int32_t hour = 0;
   int32_t minute = 0;
@@ -471,6 +475,7 @@ int64_t parseDayOfWeekText(const char* cur, const char* end, Date& date) {
     auto it = dayOfWeekMap.find(std::string_view(cur, 3));
     if (it != dayOfWeekMap.end()) {
       date.dayOfWeek = it->second.second;
+      date.hasDayOfWeek = true;
       if (end - cur >= it->second.first.size() + 3) {
         if (std::strncmp(
                 cur + 3, it->second.first.data(), it->second.first.size()) ==
@@ -627,6 +632,8 @@ std::string_view getSpecifierName(DateTimeFormatSpecifier specifier) {
       return "TIMEZONE_OFFSET_ID";
     case DateTimeFormatSpecifier::LITERAL_PERCENT:
       return "LITERAL_PERCENT";
+    case DateTimeFormatSpecifier::WEEK_OF_MONTH:
+      return "WEEK_OF_MONTH";
     default: {
       VELOX_UNREACHABLE("[Unexpected date format specifier]");
       return ""; // Make compiler happy.
@@ -643,6 +650,7 @@ int getMaxDigitConsume(
     case DateTimeFormatSpecifier::CENTURY_OF_ERA:
     case DateTimeFormatSpecifier::DAY_OF_WEEK_1_BASED:
     case DateTimeFormatSpecifier::FRACTION_OF_SECOND:
+    case DateTimeFormatSpecifier::WEEK_OF_MONTH:
       return curPattern.minRepresentDigits;
 
     case DateTimeFormatSpecifier::YEAR_OF_ERA:
@@ -735,7 +743,9 @@ int32_t parseFromPattern(
       return -1;
     }
     cur += size;
-    date.weekDateFormat = true;
+    if (!date.weekOfMonthDateFormat) {
+      date.weekDateFormat = true;
+    }
     date.dayOfYearFormat = false;
     if (!date.hasYear) {
       date.hasYear = true;
@@ -853,8 +863,10 @@ int32_t parseFromPattern(
         break;
 
       case DateTimeFormatSpecifier::MONTH_OF_YEAR:
-        if (number < 1 || number > 12) {
-          return -1;
+        if (type != DateTimeFormatterType::LENIENT_SIMPLE) {
+          if (number < 1 || number > 12) {
+            return -1;
+          }
         }
         date.month = number;
         date.weekDateFormat = false;
@@ -873,6 +885,7 @@ int32_t parseFromPattern(
         date.day = number;
         date.weekDateFormat = false;
         date.dayOfYearFormat = false;
+        date.weekOfMonthDateFormat = false;
         // Joda has this weird behavior where it returns 1970 as the year by
         // default (if no year is specified), but if either day or month are
         // specified, it fallsback to 2000.
@@ -887,6 +900,7 @@ int32_t parseFromPattern(
         date.dayOfYear = number;
         date.dayOfYearFormat = true;
         date.weekDateFormat = false;
+        date.weekOfMonthDateFormat = false;
         // Joda has this weird behavior where it returns 1970 as the year by
         // default (if no year is specified), but if either day or month are
         // specified, it fallsback to 2000.
@@ -959,6 +973,7 @@ int32_t parseFromPattern(
         date.weekDateFormat = true;
         date.dayOfYearFormat = false;
         date.centuryFormat = false;
+        date.weekOfMonthDateFormat = false;
         date.hasYear = true;
         break;
 
@@ -969,24 +984,40 @@ int32_t parseFromPattern(
         date.week = number;
         date.weekDateFormat = true;
         date.dayOfYearFormat = false;
+        date.weekOfMonthDateFormat = false;
         if (!date.hasYear) {
           date.hasYear = true;
           date.year = 2000;
         }
         break;
 
       case DateTimeFormatSpecifier::DAY_OF_WEEK_1_BASED:
-        if (number < 1 || number > 7) {
-          return -1;
+        if (type != DateTimeFormatterType::LENIENT_SIMPLE) {
+          if (number < 1 || number > 7) {
+            return -1;
+          }
         }
         date.dayOfWeek = number;
-        date.weekDateFormat = true;
+        date.hasDayOfWeek = true;
+        if (!date.weekOfMonthDateFormat) {
+          date.weekDateFormat = true;
+        }
         date.dayOfYearFormat = false;
         if (!date.hasYear) {
           date.hasYear = true;
           date.year = 2000;
         }
         break;
+      case DateTimeFormatSpecifier::WEEK_OF_MONTH:
+        date.weekOfMonthDateFormat = true;
+        date.weekOfMonth = number;
+        date.weekDateFormat = false;
+        date.hasYear = true;
+        // For week of month date format, the default value of dayOfWeek is 7.
+        if (!date.hasDayOfWeek) {
+          date.dayOfWeek = 7;
+        }
+        break;
 
       default:
         VELOX_NYI(
@@ -1018,6 +1049,7 @@ uint32_t DateTimeFormatter::maxResultSize(const tz::TimeZone* timezone) const {
         break;
       case DateTimeFormatSpecifier::DAY_OF_WEEK_0_BASED:
       case DateTimeFormatSpecifier::DAY_OF_WEEK_1_BASED:
+      case DateTimeFormatSpecifier::WEEK_OF_MONTH:
         size += std::max((int)token.pattern.minRepresentDigits, 1);
         break;
       case DateTimeFormatSpecifier::DAY_OF_WEEK_TEXT:
@@ -1328,6 +1360,18 @@ int32_t DateTimeFormatter::format(
               result);
           break;
         }
+        case DateTimeFormatSpecifier::WEEK_OF_MONTH: {
+          result += padContent(
+              ceil(
+                  (7 + static_cast<unsigned>(calDate.day()) -
+                   weekday.c_encoding() - 1) /
+                  7.0),
+              '0',
+              token.pattern.minRepresentDigits,
+              maxResultEnd,
+              result);
+          break;
+        }
         case DateTimeFormatSpecifier::WEEK_YEAR:
         default:
           VELOX_UNSUPPORTED(
@@ -1430,6 +1474,13 @@ Expected<DateTimeResult> DateTimeFormatter::parse(
   } else if (date.dayOfYearFormat) {
     daysSinceEpoch =
         util::daysSinceEpochFromDayOfYear(date.year, date.dayOfYear);
+  } else if (date.weekOfMonthDateFormat) {
+    daysSinceEpoch = util::daysSinceEpochFromWeekOfMonthDate(
+        date.year,
+        date.month,
+        date.weekOfMonth,
+        date.dayOfWeek,
+        this->type_ == DateTimeFormatterType::LENIENT_SIMPLE);
   } else {
     daysSinceEpoch =
         util::daysSinceEpochFromDate(date.year, date.month, date.day);
@@ -1792,6 +1843,9 @@ std::shared_ptr<DateTimeFormatter> buildSimpleDateTimeFormatter(
         case 'w':
           builder.appendWeekOfWeekYear(count);
           break;
+        case 'W':
+          builder.appendWeekOfMonth(count);
+          break;
         case 'x':
           builder.appendWeekYear(count);
           break;

velox/functions/lib/DateTimeFormatter.h

@@ -112,7 +112,10 @@ enum class DateTimeFormatSpecifier : uint8_t {
   TIMEZONE_OFFSET_ID = 22,
 
   // A literal % character
-  LITERAL_PERCENT = 23
+  LITERAL_PERCENT = 23,
+
+  // Week of month based on java.text.SimpleDateFormat, e.g: 2
+  WEEK_OF_MONTH = 24
 };
 
 struct FormatPattern {

velox/functions/lib/DateTimeFormatterBuilder.cpp

@@ -56,6 +56,13 @@ DateTimeFormatterBuilder& DateTimeFormatterBuilder::appendWeekOfWeekYear(
   return *this;
 }
 
+DateTimeFormatterBuilder& DateTimeFormatterBuilder::appendWeekOfMonth(
+    size_t minDigits) {
+  tokens_.emplace_back(
+      FormatPattern{DateTimeFormatSpecifier::WEEK_OF_MONTH, minDigits});
+  return *this;
+}
+
 DateTimeFormatterBuilder& DateTimeFormatterBuilder::appendDayOfWeek0Based(
     size_t minDigits) {
   tokens_.emplace_back(

velox/functions/lib/DateTimeFormatterBuilder.h

@@ -88,6 +88,16 @@ class DateTimeFormatterBuilder {
   /// will be 001
   DateTimeFormatterBuilder& appendWeekOfWeekYear(size_t minDigits);
 
+  /// Appends week of month to formatter builder, e.g: 2
+  ///
+  /// \param minDigits describes the minimum number of digits this format is
+  /// required to represent week of month. The format by default is going
+  /// use as few digits as possible greater than or equal to minDigits to
+  /// represent week of month. e.g. 1999-01-01, with min digit being 1 the
+  /// formatted result will be 1, with min digit being 4 the formatted result
+  /// will be 0001
+  DateTimeFormatterBuilder& appendWeekOfMonth(size_t minDigits);
+
   /// Appends day of week to formatter builder. The number is 0 based with 0 ~ 6
   /// representing Sunday to Saturday respectively
   ///

velox/functions/lib/tests/DateTimeFormatterTest.cpp

@@ -2303,4 +2303,128 @@ TEST_F(MysqlDateTimeTest, parseConsecutiveSpecifiers) {
   EXPECT_THROW(parseMysql("1212", "%Y%H"), VeloxUserError);
 }
 
+class SimpleDateTimeFormatterTest : public DateTimeFormatterTest {
+ protected:
+  DateTimeResult parseSimple(
+      const std::string_view& input,
+      const std::string_view& format,
+      bool lenient) {
+    auto dateTimeResultExpected =
+        buildSimpleDateTimeFormatter(format, lenient)->parse(input);
+    return dateTimeResult(dateTimeResultExpected);
+  }
+
+  std::string formatSimpleDateTime(
+      const std::string& format,
+      const Timestamp& timestamp,
+      const tz::TimeZone* timezone,
+      bool lenient) const {
+    auto formatter = buildSimpleDateTimeFormatter(format, lenient);
+    const auto maxSize = formatter->maxResultSize(timezone);
+    std::string result(maxSize, '\0');
+    auto resultSize =
+        formatter->format(timestamp, timezone, maxSize, result.data());
+    result.resize(resultSize);
+    return result;
+  }
+};
+
+TEST_F(SimpleDateTimeFormatterTest, validSimpleBuild) {
+  // W specifier case.
+  std::vector<DateTimeToken> expected = {
+      DateTimeToken(FormatPattern{DateTimeFormatSpecifier::WEEK_OF_MONTH, 1})};
+  EXPECT_EQ(expected, buildSimpleDateTimeFormatter("W", true)->tokens());
+  EXPECT_EQ(expected, buildSimpleDateTimeFormatter("W", false)->tokens());
+}
+
+TEST_F(SimpleDateTimeFormatterTest, parseSimpleWeekOfMonth) {
+  // Common cases for lenient and strict mode.
+  for (bool lenient : {true, false}) {
+    // Format contains year, month, weekOfMonth and dayOfWeek.
+    EXPECT_EQ(
+        fromTimestampString("2024-08-02"),
+        parseSimple("2024 08 01 5", "yyyy MM WW e", lenient).timestamp);
+    EXPECT_EQ(
+        fromTimestampString("2024-08-03"),
+        parseSimple("2024 08 01 6", "yyyy MM WW e", lenient).timestamp);
+    EXPECT_EQ(
+        fromTimestampString("2024-08-09"),
+        parseSimple("2024 08 02 5", "yyyy MM WW e", lenient).timestamp);
+    EXPECT_EQ(
+        fromTimestampString("2024-08-12"),
+        parseSimple("2024 08 03 1", "yyyy MM WW e", lenient).timestamp);
+
+    // Format contains year, month and weekOfMonth.
+    EXPECT_EQ(
+        fromTimestampString("2024-07-28"),
+        parseSimple("2024 08 01", "yyyy MM WW", lenient).timestamp);
+
+    // Format contains year and weekOfMonth.
+    EXPECT_EQ(
+        fromTimestampString("2023-12-31"),
+        parseSimple("2024 01", "yyyy WW", lenient).timestamp);
+
+    // Format contains weekOfMonth.
+    EXPECT_EQ(
+        fromTimestampString("1969-12-28"),
+        parseSimple("1", "W", lenient).timestamp);
+  }
+
+  // Field out of range for lenient mode.
+  EXPECT_EQ(
+      fromTimestampString("2024-09-30"),
+      parseSimple("2024 08 10 1", "yyyy MM WW e", true).timestamp);
+  EXPECT_EQ(
+      fromTimestampString("2024-07-28"),
+      parseSimple("2024 08 01", "yyyy MM WW", true).timestamp);
+  EXPECT_EQ(
+      fromTimestampString("2025-02-24"),
+      parseSimple("2024 15 01 1", "yyyy MM WW e", true).timestamp);
+  EXPECT_EQ(
+      fromTimestampString("2024-07-29"),
+      parseSimple("2024 08 01 9", "yyyy MM WW e", true).timestamp);
+
+  // Field out of range for strict mode.
+  EXPECT_THROW(
+      parseSimple("2024 08 10 1", "yyyy MM WW e", false), VeloxUserError);
+  EXPECT_THROW(parseSimple("2024 08 10", "yyyy MM WW", false), VeloxUserError);
+  EXPECT_THROW(
+      parseSimple("2024 15 01 1", "yyyy MM WW e", false), VeloxUserError);
+  EXPECT_THROW(
+      parseSimple("2024 08 01 9", "yyyy MM WW e", false), VeloxUserError);
+}
+
+TEST_F(SimpleDateTimeFormatterTest, formatResultSize) {
+  EXPECT_EQ(
+      buildSimpleDateTimeFormatter("WW", false)->maxResultSize(nullptr), 2);
+  EXPECT_EQ(
+      buildSimpleDateTimeFormatter("WW", true)->maxResultSize(nullptr), 2);
+}
+
+TEST_F(SimpleDateTimeFormatterTest, formatWeekOfMonth) {
+  auto* timezone = tz::locateZone("GMT");
+  for (bool lenient : {true, false}) {
+    EXPECT_EQ(
+        formatSimpleDateTime(
+            "W", fromTimestampString("2024-08-01"), timezone, lenient),
+        "1");
+    EXPECT_EQ(
+        formatSimpleDateTime(
+            "W", fromTimestampString("2024-08-10"), timezone, lenient),
+        "2");
+    EXPECT_EQ(
+        formatSimpleDateTime(
+            "W", fromTimestampString("2024-08-11"), timezone, lenient),
+        "3");
+    EXPECT_EQ(
+        formatSimpleDateTime(
+            "W", fromTimestampString("2024-08-15"), timezone, lenient),
+        "3");
+    EXPECT_EQ(
+        formatSimpleDateTime(
+            "W", fromTimestampString("2024-08-30"), timezone, lenient),
+        "5");
+  }
+}
+
 } // namespace facebook::velox::functions