Vertica::VString Class Reference

Representation of a String in Vertica. All character data is internally encoded as UTF-8 characters and is not NULL terminated.

Collaboration diagram for Vertica::VString:

Public Member Functions
	VString (const VString &other)
void	alloc (vsize len)
	Allocate the VString's internal buffer and initialize to 'len' 0 bytes.
int	compare (const VString *other) const
	Compares this VString to another.
void	copy (const char *s, vsize len)
	Copy character data from C string to the VString's internal buffer.
void	copy (const char *s)
	Copy character data from null terminated C string to the VString's internal buffer.
void	copy (const std::string &s)
	Copy character data from std::string.
void	copy (const VString *from)
	Copy data from another VString.
void	copy (const VString &from)
	Copy data from another VString.
const char *	data () const
	Provides a read-only pointer to this VString's internal data.
char *	data ()
	Provides a writeable pointer to this VString's internal data.
int	equal (const VString *other) const
	Indicates whether some other VString is equal to this one.
bool	isNull () const
	Indicates if this VString contains the SQL NULL value.
vsize	length () const
	Returns the length of this VString.
bool	operator
VString &	operator= (const stringtype &s)
VString &	operator= (const VString &other)
bool	operator== (const VString &other) const
bool	operator> (const VString &other) const
bool	operator>= (const VString &other) const
void	setNull ()
	Sets this VString to the SQL NULL value.
template
stringtype	str () const
	Provides a copy of this VString's data as a std::string.

Detailed Description

Representation of a String in Vertica. All character data is internally encoded as UTF-8 characters and is not NULL terminated.

Member Function Documentation

void Vertica::VString::alloc(vsize len)

inline Allocate the VString's internal buffer and initialize to 'len' 0 bytes.

The VString is allocated and set to 'len' zero bytes. It is the caller's responsibility to not provide a value of 'len' that is larger than the maximum size of this VString

Parameters

• len: length in bytes

int Vertica::VString::compare(const VString * other) const

inline Compares this VString to another.

Returns -1 if this < other, 0 if equal, 1 if this > other (just like memcmp)

Note SQL NULL compares greater than anything else; two SQL NULLs are considered equal

void Vertica::VString::copy(const char * s, vsize len)

inline Copy character data from C string to the VString's internal buffer.

Data is copied from s into this VString. It is the caller's responsibility to not provide a value of 'len' that is larger than the maximum size of this VString

Parameters

• s: character input data
• len: length in bytes, not including the terminating null character

Referenced by

• copy()
• operator=()

void Vertica::VString::copy(const char * s)

inline Copy character data from null terminated C string to the VString's internal buffer.

Parameters

• s: null-terminated character input data

Referenced by copy().

void Vertica::VString::copy(const std::string & s)

inline Copy character data from std::string.

Parameters

• s: null-terminated character input data

Referenced by copy().

void Vertica::VString::copy(const VString * from)

inline Copy data from another VString.

Parameters

• from: The source VString

void Vertica::VString::copy(const VString & from)

inline Copy data from another VString.

Parameters

• from: The source VString

Referenced by copy().

const char* Vertica::VString::data() const

inline Provides a read-only pointer to this VString's internal data.

Returns the read only character data for this string, as a pointer.

Note The returned string is not null terminated

Referenced by

• alloc()
• copy()
• str()

char* Vertica::VString::data()

inline Provides a writeable pointer to this VString's internal data.

Returns the writeable character data for this string, as a pointer.

Note The returned string is not null terminated

int Vertica::VString::equal(const VString * other) const

inline Indicates whether some other VString is equal to this one.

Returns -1 if both are SQL NULL, 0 if not equal, 1 if equal so you can easily consider two NULL values to be equal to each other, or not

bool Vertica::VString::isNull() const

inline Indicates if this VString contains the SQL NULL value.

Returns true if this string contains the SQL NULL value, false otherwise

Referenced by

• copy()
• Vertica::BlockReader::isNull()
• Vertica::ValueRangeReader::isNull()
• str()

vsize Vertica::VString::length() const

inline Returns the length of this VString.

Returns the length of the string, in bytes. Does not include any extra space for null characters.

Referenced by

• copy()
• str()

template<typename stringtype >

VString& Vertica::VString::operator=(const stringtype & s)

inline Set this object to have the contents of any string object

VString& Vertica::VString::operator=(const VString & other)

inline Copy this object to have the same contents of another VString

template<typename stringtype = std::string>

stringtype Vertica::VString::str() const

inline Provides a copy of this VString's data as a std::string.

Returns a std::string copy of the data in this VString

Referenced by Vertica::operator+().