ClickHouse/dbms/include/DB/IO/ReadHelpers.h
2013-10-10 23:06:51 +00:00

612 lines
16 KiB
C++
Raw Blame History

This file contains ambiguous Unicode characters

This file contains Unicode characters that might be confused with other characters. If you think that this is intentional, you can safely ignore this warning. Use the Escape button to reveal them.

#pragma once
#include <cstring>
#include <limits>
#include <algorithm>
#include <tr1/type_traits>
#include <Yandex/Common.h>
#include <Yandex/DateLUT.h>
#include <mysqlxx/Date.h>
#include <mysqlxx/DateTime.h>
#include <DB/Core/Types.h>
#include <DB/Core/Exception.h>
#include <DB/Core/ErrorCodes.h>
#include <DB/IO/ReadBuffer.h>
#include <DB/IO/VarInt.h>
#define DEFAULT_MAX_STRING_SIZE 0x00FFFFFFULL
namespace DB
{
/// Функции-помошники для форматированного чтения
static inline char parseEscapeSequence(char c)
{
switch(c)
{
case 'b':
return '\b';
case 'f':
return '\f';
case 'n':
return '\n';
case 'r':
return '\r';
case 't':
return '\t';
case '0':
return '\0';
default:
return c;
}
}
static inline void throwReadAfterEOF()
{
throw Exception("Attempt to read after eof", ErrorCodes::ATTEMPT_TO_READ_AFTER_EOF);
}
/// Чтение POD-типа в native формате
template <typename T>
inline void readPODBinary(T & x, ReadBuffer & buf)
{
buf.readStrict(reinterpret_cast<char *>(&x), sizeof(x));
}
template <typename T>
inline void readIntBinary(T & x, ReadBuffer & buf)
{
readPODBinary(x, buf);
}
template <typename T>
inline void readFloatBinary(T & x, ReadBuffer & buf)
{
readPODBinary(x, buf);
}
inline void readStringBinary(std::string & s, ReadBuffer & buf, size_t MAX_STRING_SIZE = DEFAULT_MAX_STRING_SIZE)
{
size_t size = 0;
readVarUInt(size, buf);
if (size > MAX_STRING_SIZE)
throw Poco::Exception("Too large string size.");
s.resize(size);
buf.readStrict(&s[0], size);
}
template <typename T>
void readVectorBinary(std::vector<T> & v, ReadBuffer & buf, size_t MAX_VECTOR_SIZE = DEFAULT_MAX_STRING_SIZE)
{
size_t size = 0;
readVarUInt(size, buf);
if (size > MAX_VECTOR_SIZE)
throw Poco::Exception("Too large vector size.");
v.resize(size);
for (size_t i = 0; i < size; ++i)
readBinary(v[i], buf);
}
inline void readChar(char & x, ReadBuffer & buf)
{
if (!buf.eof())
{
x = *buf.position();
++buf.position();
}
else
throwReadAfterEOF();
}
void assertString(const char * s, ReadBuffer & buf);
inline void readBoolText(bool & x, ReadBuffer & buf)
{
char tmp = '0';
readChar(tmp, buf);
x = tmp != '0';
}
template <typename T>
void readIntText(T & x, ReadBuffer & buf)
{
bool negative = false;
x = 0;
if (buf.eof())
throwReadAfterEOF();
while (!buf.eof())
{
switch (*buf.position())
{
case '+':
break;
case '-':
if (std::tr1::is_signed<T>::value)
negative = true;
else
return;
break;
case '0':
case '1':
case '2':
case '3':
case '4':
case '5':
case '6':
case '7':
case '8':
case '9':
x *= 10;
x += *buf.position() - '0';
break;
default:
if (negative)
x = -x;
return;
}
++buf.position();
}
if (negative)
x = -x;
}
/** Более оптимизированная версия (примерно в 1.5 раза на реальных данных).
* Отличается тем, что:
* - из чисел, начинающихся на ноль, парсится только ноль;
* - не поддерживается символ '+' перед числом;
* - символы :;<=>? парсятся, как некоторые цифры.
*/
template <typename T>
void readIntTextUnsafe(T & x, ReadBuffer & buf)
{
bool negative = false;
x = 0;
if (unlikely(buf.eof()))
throwReadAfterEOF();
if (std::tr1::is_signed<T>::value && *buf.position() == '-')
{
++buf.position();
negative = true;
if (unlikely(buf.eof()))
throwReadAfterEOF();
}
if (*buf.position() == '0') /// В реальных данных много нулей.
{
++buf.position();
return;
}
while (!buf.eof())
{
if ((*buf.position() & 0xF0) == 0x30) /// Имеет смысл, что это условие находится внутри цикла.
{
x *= 10;
x += *buf.position() & 0x0F;
++buf.position();
}
else
break;
}
if (std::tr1::is_signed<T>::value && negative)
x = -x;
}
/// грубо
template <typename T>
void readFloatText(T & x, ReadBuffer & buf)
{
bool negative = false;
x = 0;
bool after_point = false;
double power_of_ten = 1;
if (buf.eof())
throwReadAfterEOF();
while (!buf.eof())
{
switch (*buf.position())
{
case '+':
break;
case '-':
negative = true;
break;
case '.':
after_point = true;
break;
case '0':
case '1':
case '2':
case '3':
case '4':
case '5':
case '6':
case '7':
case '8':
case '9':
if (after_point)
{
power_of_ten /= 10;
x += (*buf.position() - '0') * power_of_ten;
}
else
{
x *= 10;
x += *buf.position() - '0';
}
break;
case 'e':
case 'E':
{
++buf.position();
Int32 exponent = 0;
readIntText(exponent, buf);
if (exponent == 0)
{
if (negative)
x = -x;
return;
}
else if (exponent > 0)
{
for (Int32 i = 0; i < exponent; ++i)
x *= 10;
if (negative)
x = -x;
return;
}
else
{
for (Int32 i = 0; i < exponent; ++i)
x /= 10;
if (negative)
x = -x;
return;
}
}
case 'i':
++buf.position();
assertString("nf", buf);
x = std::numeric_limits<T>::infinity();
if (negative)
x = -x;
return;
case 'I':
++buf.position();
assertString("NF", buf);
x = std::numeric_limits<T>::infinity();
if (negative)
x = -x;
return;
case 'n':
++buf.position();
assertString("an", buf);
x = std::numeric_limits<T>::quiet_NaN();
return;
case 'N':
++buf.position();
assertString("AN", buf);
x = std::numeric_limits<T>::quiet_NaN();
return;
default:
if (negative)
x = -x;
return;
}
++buf.position();
}
if (negative)
x = -x;
}
/// грубо; всё до '\n' или '\t'
void readString(String & s, ReadBuffer & buf);
void readEscapedString(String & s, ReadBuffer & buf);
void readQuotedString(String & s, ReadBuffer & buf);
void readDoubleQuotedString(String & s, ReadBuffer & buf);
void readBackQuotedString(String & s, ReadBuffer & buf);
/// в формате YYYY-MM-DD
inline void readDateText(DayNum_t & date, ReadBuffer & buf)
{
char s[10];
size_t size = buf.read(s, 10);
if (10 != size)
{
s[size] = 0;
throw Exception(std::string("Cannot parse date ") + s, ErrorCodes::CANNOT_PARSE_DATE);
}
UInt16 year = (s[0] - '0') * 1000 + (s[1] - '0') * 100 + (s[2] - '0') * 10 + (s[3] - '0');
UInt8 month = (s[5] - '0') * 10 + (s[6] - '0');
UInt8 day = (s[8] - '0') * 10 + (s[9] - '0');
date = DateLUTSingleton::instance().makeDayNum(year, month, day);
}
inline void readDateText(mysqlxx::Date & date, ReadBuffer & buf)
{
char s[10];
size_t size = buf.read(s, 10);
if (10 != size)
{
s[size] = 0;
throw Exception(std::string("Cannot parse date ") + s, ErrorCodes::CANNOT_PARSE_DATE);
}
date.year((s[0] - '0') * 1000 + (s[1] - '0') * 100 + (s[2] - '0') * 10 + (s[3] - '0'));
date.month((s[5] - '0') * 10 + (s[6] - '0'));
date.day((s[8] - '0') * 10 + (s[9] - '0'));
}
/// в формате YYYY-MM-DD HH:MM:SS, согласно текущему часовому поясу
inline void readDateTimeText(time_t & datetime, ReadBuffer & buf)
{
char s[19];
size_t size = buf.read(s, 19);
if (19 != size)
{
s[size] = 0;
throw Exception(std::string("Cannot parse datetime ") + s, ErrorCodes::CANNOT_PARSE_DATETIME);
}
UInt16 year = (s[0] - '0') * 1000 + (s[1] - '0') * 100 + (s[2] - '0') * 10 + (s[3] - '0');
UInt8 month = (s[5] - '0') * 10 + (s[6] - '0');
UInt8 day = (s[8] - '0') * 10 + (s[9] - '0');
UInt8 hour = (s[11] - '0') * 10 + (s[12] - '0');
UInt8 minute = (s[14] - '0') * 10 + (s[15] - '0');
UInt8 second = (s[17] - '0') * 10 + (s[18] - '0');
if (unlikely(year == 0))
datetime = 0;
else
datetime = DateLUTSingleton::instance().makeDateTime(year, month, day, hour, minute, second);
}
inline void readDateTimeText(mysqlxx::DateTime & datetime, ReadBuffer & buf)
{
char s[19];
size_t size = buf.read(s, 19);
if (19 != size)
{
s[size] = 0;
throw Exception(std::string("Cannot parse datetime ") + s, ErrorCodes::CANNOT_PARSE_DATETIME);
}
datetime.year((s[0] - '0') * 1000 + (s[1] - '0') * 100 + (s[2] - '0') * 10 + (s[3] - '0'));
datetime.month((s[5] - '0') * 10 + (s[6] - '0'));
datetime.day((s[8] - '0') * 10 + (s[9] - '0'));
datetime.hour((s[11] - '0') * 10 + (s[12] - '0'));
datetime.minute((s[14] - '0') * 10 + (s[15] - '0'));
datetime.second((s[17] - '0') * 10 + (s[18] - '0'));
}
/// Общие методы для чтения значения в бинарном формате.
inline void readBinary(UInt8 & x, ReadBuffer & buf) { readPODBinary(x, buf); }
inline void readBinary(UInt16 & x, ReadBuffer & buf) { readPODBinary(x, buf); }
inline void readBinary(UInt32 & x, ReadBuffer & buf) { readPODBinary(x, buf); }
inline void readBinary(UInt64 & x, ReadBuffer & buf) { readPODBinary(x, buf); }
inline void readBinary(Int8 & x, ReadBuffer & buf) { readPODBinary(x, buf); }
inline void readBinary(Int16 & x, ReadBuffer & buf) { readPODBinary(x, buf); }
inline void readBinary(Int32 & x, ReadBuffer & buf) { readPODBinary(x, buf); }
inline void readBinary(Int64 & x, ReadBuffer & buf) { readPODBinary(x, buf); }
inline void readBinary(Float32 & x, ReadBuffer & buf) { readPODBinary(x, buf); }
inline void readBinary(Float64 & x, ReadBuffer & buf) { readPODBinary(x, buf); }
inline void readBinary(String & x, ReadBuffer & buf) { readStringBinary(x, buf); }
inline void readBinary(bool & x, ReadBuffer & buf) { readPODBinary(x, buf); }
inline void readBinary(VisitID_t & x, ReadBuffer & buf) { readPODBinary(x, buf); }
inline void readBinary(mysqlxx::Date & x, ReadBuffer & buf) { readPODBinary(x, buf); }
inline void readBinary(mysqlxx::DateTime & x, ReadBuffer & buf) { readPODBinary(x, buf); }
/// Общие методы для чтения значения в текстовом виде из tab-separated формата.
inline void readText(UInt8 & x, ReadBuffer & buf) { readIntText(x, buf); }
inline void readText(UInt16 & x, ReadBuffer & buf) { readIntText(x, buf); }
inline void readText(UInt32 & x, ReadBuffer & buf) { readIntText(x, buf); }
inline void readText(UInt64 & x, ReadBuffer & buf) { readIntText(x, buf); }
inline void readText(Int8 & x, ReadBuffer & buf) { readIntText(x, buf); }
inline void readText(Int16 & x, ReadBuffer & buf) { readIntText(x, buf); }
inline void readText(Int32 & x, ReadBuffer & buf) { readIntText(x, buf); }
inline void readText(Int64 & x, ReadBuffer & buf) { readIntText(x, buf); }
inline void readText(Float32 & x, ReadBuffer & buf) { readFloatText(x, buf); }
inline void readText(Float64 & x, ReadBuffer & buf) { readFloatText(x, buf); }
inline void readText(String & x, ReadBuffer & buf) { readEscapedString(x, buf); }
inline void readText(bool & x, ReadBuffer & buf) { readBoolText(x, buf); }
inline void readText(VisitID_t & x, ReadBuffer & buf) { readIntText(x, buf); }
inline void readText(mysqlxx::Date & x, ReadBuffer & buf) { readDateText(x, buf); }
inline void readText(mysqlxx::DateTime & x, ReadBuffer & buf) { readDateTimeText(x, buf); }
/// Общие методы для чтения значения в текстовом виде, при необходимости, в кавычках.
inline void readQuoted(UInt8 & x, ReadBuffer & buf) { readIntText(x, buf); }
inline void readQuoted(UInt16 & x, ReadBuffer & buf) { readIntText(x, buf); }
inline void readQuoted(UInt32 & x, ReadBuffer & buf) { readIntText(x, buf); }
inline void readQuoted(UInt64 & x, ReadBuffer & buf) { readIntText(x, buf); }
inline void readQuoted(Int8 & x, ReadBuffer & buf) { readIntText(x, buf); }
inline void readQuoted(Int16 & x, ReadBuffer & buf) { readIntText(x, buf); }
inline void readQuoted(Int32 & x, ReadBuffer & buf) { readIntText(x, buf); }
inline void readQuoted(Int64 & x, ReadBuffer & buf) { readIntText(x, buf); }
inline void readQuoted(Float32 & x, ReadBuffer & buf) { readFloatText(x, buf); }
inline void readQuoted(Float64 & x, ReadBuffer & buf) { readFloatText(x, buf); }
inline void readQuoted(String & x, ReadBuffer & buf) { readQuotedString(x, buf); }
inline void readQuoted(bool & x, ReadBuffer & buf) { readBoolText(x, buf); }
inline void readQuoted(VisitID_t & x, ReadBuffer & buf) { readIntText(x, buf); }
inline void readQuoted(mysqlxx::Date & x, ReadBuffer & buf)
{
assertString("'", buf);
readDateText(x, buf);
assertString("'", buf);
}
inline void readQuoted(mysqlxx::DateTime & x, ReadBuffer & buf)
{
assertString("'", buf);
readDateTimeText(x, buf);
assertString("'", buf);
}
/// В двойных кавычках
inline void readDoubleQuoted(UInt8 & x, ReadBuffer & buf) { readIntText(x, buf); }
inline void readDoubleQuoted(UInt16 & x, ReadBuffer & buf) { readIntText(x, buf); }
inline void readDoubleQuoted(UInt32 & x, ReadBuffer & buf) { readIntText(x, buf); }
inline void readDoubleQuoted(UInt64 & x, ReadBuffer & buf) { readIntText(x, buf); }
inline void readDoubleQuoted(Int8 & x, ReadBuffer & buf) { readIntText(x, buf); }
inline void readDoubleQuoted(Int16 & x, ReadBuffer & buf) { readIntText(x, buf); }
inline void readDoubleQuoted(Int32 & x, ReadBuffer & buf) { readIntText(x, buf); }
inline void readDoubleQuoted(Int64 & x, ReadBuffer & buf) { readIntText(x, buf); }
inline void readDoubleQuoted(Float32 & x, ReadBuffer & buf) { readFloatText(x, buf); }
inline void readDoubleQuoted(Float64 & x, ReadBuffer & buf) { readFloatText(x, buf); }
inline void readDoubleQuoted(String & x, ReadBuffer & buf) { readDoubleQuotedString(x, buf); }
inline void readDoubleQuoted(bool & x, ReadBuffer & buf) { readBoolText(x, buf); }
inline void readDoubleQuoted(VisitID_t & x, ReadBuffer & buf) { readIntText(x, buf); }
inline void readDoubleQuoted(mysqlxx::Date & x, ReadBuffer & buf)
{
assertString("\"", buf);
readDateText(x, buf);
assertString("\"", buf);
}
inline void readDoubleQuoted(mysqlxx::DateTime & x, ReadBuffer & buf)
{
assertString("\"", buf);
readDateTimeText(x, buf);
assertString("\"", buf);
}
/// Пропустить пробельные символы.
inline void skipWhitespaceIfAny(ReadBuffer & buf)
{
while (!buf.eof()
&& (*buf.position() == ' '
|| *buf.position() == '\t'
|| *buf.position() == '\n'
|| *buf.position() == '\r'
|| *buf.position() == '\f'))
++buf.position();
}
/** Прочитать сериализованный эксепшен.
* При сериализации/десериализации часть информации теряется
* (тип обрезается до базового, message заменяется на displayText, и stack trace дописывается в message)
* К нему может быть добавлено дополнительное сообщение (например, вы можете указать, откуда оно было прочитано).
*/
void readException(Exception & e, ReadBuffer & buf, const String & additional_message = "");
void readAndThrowException(ReadBuffer & buf, const String & additional_message = "");
/** Вспомогательная функция
*/
template <typename T>
static inline const char * tryReadIntText(T & x, const char * pos, const char * end)
{
bool negative = false;
x = 0;
if (pos >= end)
return pos;
while (pos < end)
{
switch (*pos)
{
case '+':
break;
case '-':
if (std::tr1::is_signed<T>::value)
negative = true;
else
return pos;
break;
case '0':
case '1':
case '2':
case '3':
case '4':
case '5':
case '6':
case '7':
case '8':
case '9':
x *= 10;
x += *pos - '0';
break;
default:
if (negative)
x = -x;
return pos;
}
++pos;
}
if (negative)
x = -x;
return pos;
}
/// Простые для использования методы чтения чего-либо из строки в текстовом виде.
template <typename T>
inline T parse(const char * data, size_t size)
{
T res;
ReadBuffer buf(const_cast<char *>(data), size, 0);
readText(res, buf);
return res;
}
template <typename T>
inline T parse(const char * data)
{
return parse<T>(data, strlen(data));
}
template <typename T>
inline T parse(const String & s)
{
return parse<T>(s.data(), s.size());
}
}