// Copyright 2011 the V8 project authors. All rights reserved. // Use of this source code is governed by a BSD-style license that can be // found in the LICENSE file. #ifndef V8_DATE_DATEPARSER_H_ #define V8_DATE_DATEPARSER_H_ #include "src/strings/char-predicates.h" #include "src/utils/allocation.h" namespace v8 { namespace internal { class DateParser : public AllStatic { public: enum { YEAR, MONTH, DAY, HOUR, MINUTE, SECOND, MILLISECOND, UTC_OFFSET, OUTPUT_SIZE }; // Parse the string as a date. If parsing succeeds, return true after // filling out the output array as follows (all integers are Smis): // [0]: year // [1]: month (0 = Jan, 1 = Feb, ...) // [2]: day // [3]: hour // [4]: minute // [5]: second // [6]: millisecond // [7]: UTC offset in seconds, or null value if no timezone specified // If parsing fails, return false (content of output array is not defined). template <typename Char> static bool Parse(Isolate* isolate, Vector<Char> str, double* output); private: // Range testing static inline bool Between(int x, int lo, int hi) { return static_cast<unsigned>(x - lo) <= static_cast<unsigned>(hi - lo); } // Indicates a missing value. static const int kNone = kMaxInt; // Maximal number of digits used to build the value of a numeral. // Remaining digits are ignored. static const int kMaxSignificantDigits = 9; // InputReader provides basic string parsing and character classification. template <typename Char> class InputReader { public: explicit InputReader(Vector<Char> s) : index_(0), buffer_(s) { Next(); } int position() { return index_; } // Advance to the next character of the string. void Next() { ch_ = (index_ < buffer_.length()) ? buffer_[index_] : 0; index_++; } // Read a string of digits as an unsigned number. Cap value at // kMaxSignificantDigits, but skip remaining digits if the numeral // is longer. int ReadUnsignedNumeral() { int n = 0; int i = 0; while (IsAsciiDigit()) { if (i < kMaxSignificantDigits) n = n * 10 + ch_ - '0'; i++; Next(); } return n; } // Read a word (sequence of chars. >= 'A'), fill the given buffer with a // lower-case prefix, and pad any remainder of the buffer with zeroes. // Return word length. int ReadWord(uint32_t* prefix, int prefix_size) { int len; for (len = 0; IsAsciiAlphaOrAbove(); Next(), len++) { if (len < prefix_size) prefix[len] = AsciiAlphaToLower(ch_); } for (int i = len; i < prefix_size; i++) prefix[i] = 0; return len; } // The skip methods return whether they actually skipped something. bool Skip(uint32_t c) { if (ch_ == c) { Next(); return true; } return false; } inline bool SkipWhiteSpace(); inline bool SkipParentheses(); // Character testing/classification. Non-ASCII digits are not supported. bool Is(uint32_t c) const { return ch_ == c; } bool IsEnd() const { return ch_ == 0; } bool IsAsciiDigit() const { return IsDecimalDigit(ch_); } bool IsAsciiAlphaOrAbove() const { return ch_ >= 'A'; } bool IsAsciiSign() const { return ch_ == '+' || ch_ == '-'; } // Return 1 for '+' and -1 for '-'. int GetAsciiSignValue() const { return 44 - static_cast<int>(ch_); } private: int index_; Vector<Char> buffer_; uint32_t ch_; }; enum KeywordType { INVALID, MONTH_NAME, TIME_ZONE_NAME, TIME_SEPARATOR, AM_PM }; struct DateToken { public: bool IsInvalid() { return tag_ == kInvalidTokenTag; } bool IsUnknown() { return tag_ == kUnknownTokenTag; } bool IsNumber() { return tag_ == kNumberTag; } bool IsSymbol() { return tag_ == kSymbolTag; } bool IsWhiteSpace() { return tag_ == kWhiteSpaceTag; } bool IsEndOfInput() { return tag_ == kEndOfInputTag; } bool IsKeyword() { return tag_ >= kKeywordTagStart; } int length() { return length_; } int number() { DCHECK(IsNumber()); return value_; } KeywordType keyword_type() { DCHECK(IsKeyword()); return static_cast<KeywordType>(tag_); } int keyword_value() { DCHECK(IsKeyword()); return value_; } char symbol() { DCHECK(IsSymbol()); return static_cast<char>(value_); } bool IsSymbol(char symbol) { return IsSymbol() && this->symbol() == symbol; } bool IsKeywordType(KeywordType tag) { return tag_ == tag; } bool IsFixedLengthNumber(int length) { return IsNumber() && length_ == length; } bool IsAsciiSign() { return tag_ == kSymbolTag && (value_ == '-' || value_ == '+'); } int ascii_sign() { DCHECK(IsAsciiSign()); return 44 - value_; } bool IsKeywordZ() { return IsKeywordType(TIME_ZONE_NAME) && length_ == 1 && value_ == 0; } bool IsUnknown(int character) { return IsUnknown() && value_ == character; } // Factory functions. static DateToken Keyword(KeywordType tag, int value, int length) { return DateToken(tag, length, value); } static DateToken Number(int value, int length) { return DateToken(kNumberTag, length, value); } static DateToken Symbol(char symbol) { return DateToken(kSymbolTag, 1, symbol); } static DateToken EndOfInput() { return DateToken(kEndOfInputTag, 0, -1); } static DateToken WhiteSpace(int length) { return DateToken(kWhiteSpaceTag, length, -1); } static DateToken Unknown() { return DateToken(kUnknownTokenTag, 1, -1); } static DateToken Invalid() { return DateToken(kInvalidTokenTag, 0, -1); } private: enum TagType { kInvalidTokenTag = -6, kUnknownTokenTag = -5, kWhiteSpaceTag = -4, kNumberTag = -3, kSymbolTag = -2, kEndOfInputTag = -1, kKeywordTagStart = 0 }; DateToken(int tag, int length, int value) : tag_(tag), length_(length), value_(value) {} int tag_; int length_; // Number of characters. int value_; }; template <typename Char> class DateStringTokenizer { public: explicit DateStringTokenizer(InputReader<Char>* in) : in_(in), next_(Scan()) {} DateToken Next() { DateToken result = next_; next_ = Scan(); return result; } DateToken Peek() { return next_; } bool SkipSymbol(char symbol) { if (next_.IsSymbol(symbol)) { next_ = Scan(); return true; } return false; } private: DateToken Scan(); InputReader<Char>* in_; DateToken next_; }; static int ReadMilliseconds(DateToken number); // KeywordTable maps names of months, time zones, am/pm to numbers. class KeywordTable : public AllStatic { public: // Look up a word in the keyword table and return an index. // 'pre' contains a prefix of the word, zero-padded to size kPrefixLength // and 'len' is the word length. static int Lookup(const uint32_t* pre, int len); // Get the type of the keyword at index i. static KeywordType GetType(int i) { return static_cast<KeywordType>(array[i][kTypeOffset]); } // Get the value of the keyword at index i. static int GetValue(int i) { return array[i][kValueOffset]; } static const int kPrefixLength = 3; static const int kTypeOffset = kPrefixLength; static const int kValueOffset = kTypeOffset + 1; static const int kEntrySize = kValueOffset + 1; static const int8_t array[][kEntrySize]; }; class TimeZoneComposer { public: TimeZoneComposer() : sign_(kNone), hour_(kNone), minute_(kNone) {} void Set(int offset_in_hours) { sign_ = offset_in_hours < 0 ? -1 : 1; hour_ = offset_in_hours * sign_; minute_ = 0; } void SetSign(int sign) { sign_ = sign < 0 ? -1 : 1; } void SetAbsoluteHour(int hour) { hour_ = hour; } void SetAbsoluteMinute(int minute) { minute_ = minute; } bool IsExpecting(int n) const { return hour_ != kNone && minute_ == kNone && TimeComposer::IsMinute(n); } bool IsUTC() const { return hour_ == 0 && minute_ == 0; } bool Write(double* output); bool IsEmpty() { return hour_ == kNone; } private: int sign_; int hour_; int minute_; }; class TimeComposer { public: TimeComposer() : index_(0), hour_offset_(kNone) {} bool IsEmpty() const { return index_ == 0; } bool IsExpecting(int n) const { return (index_ == 1 && IsMinute(n)) || (index_ == 2 && IsSecond(n)) || (index_ == 3 && IsMillisecond(n)); } bool Add(int n) { return index_ < kSize ? (comp_[index_++] = n, true) : false; } bool AddFinal(int n) { if (!Add(n)) return false; while (index_ < kSize) comp_[index_++] = 0; return true; } void SetHourOffset(int n) { hour_offset_ = n; } bool Write(double* output); static bool IsMinute(int x) { return Between(x, 0, 59); } static bool IsHour(int x) { return Between(x, 0, 23); } static bool IsSecond(int x) { return Between(x, 0, 59); } private: static bool IsHour12(int x) { return Between(x, 0, 12); } static bool IsMillisecond(int x) { return Between(x, 0, 999); } static const int kSize = 4; int comp_[kSize]; int index_; int hour_offset_; }; class DayComposer { public: DayComposer() : index_(0), named_month_(kNone), is_iso_date_(false) {} bool IsEmpty() const { return index_ == 0; } bool Add(int n) { if (index_ < kSize) { comp_[index_] = n; index_++; return true; } return false; } void SetNamedMonth(int n) { named_month_ = n; } bool Write(double* output); void set_iso_date() { is_iso_date_ = true; } static bool IsMonth(int x) { return Between(x, 1, 12); } static bool IsDay(int x) { return Between(x, 1, 31); } private: static const int kSize = 3; int comp_[kSize]; int index_; int named_month_; // If set, ensures that data is always parsed in year-month-date order. bool is_iso_date_; }; // Tries to parse an ES5 Date Time String. Returns the next token // to continue with in the legacy date string parser. If parsing is // complete, returns DateToken::EndOfInput(). If terminally unsuccessful, // returns DateToken::Invalid(). Otherwise parsing continues in the // legacy parser. template <typename Char> static DateParser::DateToken ParseES5DateTime( DateStringTokenizer<Char>* scanner, DayComposer* day, TimeComposer* time, TimeZoneComposer* tz); }; } // namespace internal } // namespace v8 #endif // V8_DATE_DATEPARSER_H_