moab::SysUtil Namespace Reference

Functions
void	setmem (void *mem, const void *value, unsigned value_size, size_t num_elem)
	Similar to memset, but accepts values larger than 1 char. More...
long	filesize (FILE *filp)
	Get size of file (if it is a regular file) More...
long	filesize (std::ifstream &str)
	Get size of file (if it is a regular file) More...
void	byteswap (void *data, unsigned value_size, size_t num_elem)
	Swap byte order (e.g. change from big-endian to little-endian) More...
static uint16_t	swap_bytes (uint16_t value)
static uint32_t	swap_bytes (uint32_t value)
static uint64_t	swap_bytes (uint64_t value)
void	byteswap2 (void *data, size_t num_elem)
	Alternate byteswap optimized for 2-byte values. More...
void	byteswap4 (void *data, size_t num_elem)
	Alternate byteswap optimized for 4-byte values. More...
void	byteswap8 (void *data, size_t num_elem)
	Alternate byteswap optimized for 8-byte values. More...
bool	little_endian ()
	Check if platform is little-endian. More...
bool	big_endian ()
	Check if platform is big-endian. More...
template<typename T >
void	byteswap (T *data, size_t num_elem)
	Type-specific byte swap. More...

Variables
const uint64_t	m64b1 = 0xFF
const uint64_t	m64b2 = m64b1 << 8
const uint64_t	m64b3 = m64b1 << 16
const uint64_t	m64b4 = m64b1 << 24
const uint64_t	m64b5 = m64b1 << 32
const uint64_t	m64b6 = m64b1 << 40
const uint64_t	m64b7 = m64b1 << 48

Function Documentation

big_endian()

bool moab::SysUtil::big_endian ( )

inline

Check if platform is big-endian.

Check if platform is big-endian (least significant byte at lowest memory address.)

Definition at line 61 of file SysUtil.hpp.

 {
 const unsigned one = 1;
 return !( ( (char*)&one )[sizeof( unsigned ) - 1] );
 }

Referenced by moab::ReadSTL::load_file(), and moab::WriteSTL::write_file().

byteswap() [1/2]

template<typename T >

void moab::SysUtil::byteswap ( T *  data, size_t  num_elem  )

inline

Type-specific byte swap.

Definition at line 85 of file SysUtil.hpp.

 {
 switch( sizeof( T ) )
 {
 case 1:
 break;
 case 2:
 byteswap2( data, num_elem );
 break;
 case 4:
 byteswap4( data, num_elem );
 break;
 case 8:
 byteswap8( data, num_elem );
 break;
 default:
 byteswap( data, sizeof( T ), num_elem );
 break;
 }
 }

References byteswap(), byteswap2(), byteswap4(), byteswap8(), and T.

byteswap() [2/2]

void moab::SysUtil::byteswap	(	void *	data,
		unsigned	value_size,
		size_t	num_elem
	)

Swap byte order (e.g. change from big-endian to little-endian)

Reverse byte order or array of values.

Parameters

data	Pointer to beginning of memory block to modify
values_size	Size of one value
num_elem	Number of values of size 'value_size' in 'data'

Definition at line 57 of file SysUtil.cpp.

 {
 char* mem = reinterpret_cast< char* >( data );
 char* const end = mem + value_size * num_elem;
 for( ; mem < end; mem += value_size )
 {
 unsigned i = 0, j = value_size - 1;
 while( i < j )
 std::swap( mem[i++], mem[j--] );
 }
 }

Referenced by moab::ReadSTL::binary_read_triangles(), moab::WriteSTL::binary_write_triangles(), and byteswap().

byteswap2()

void moab::SysUtil::byteswap2	(	void *	data,
		size_t	num_elem
	)

Alternate byteswap optimized for 2-byte values.

Definition at line 128 of file SysUtil.cpp.

 {
 uint16_t* mem = reinterpret_cast< uint16_t* >( data );
 uint16_t* end = mem + num_elem;
 for( ; mem < end; ++mem )
 *mem = swap_bytes( *mem );
 }

References swap_bytes().

Referenced by byteswap().

byteswap4()

void moab::SysUtil::byteswap4	(	void *	data,
		size_t	num_elem
	)

Alternate byteswap optimized for 4-byte values.

Definition at line 136 of file SysUtil.cpp.

 {
 uint32_t* mem = reinterpret_cast< uint32_t* >( data );
 uint32_t* end = mem + num_elem;
 for( ; mem < end; ++mem )
 *mem = swap_bytes( *mem );
 }

References swap_bytes().

Referenced by byteswap().

byteswap8()

void moab::SysUtil::byteswap8	(	void *	data,
		size_t	num_elem
	)

Alternate byteswap optimized for 8-byte values.

Definition at line 144 of file SysUtil.cpp.

 {
 if( sizeof( void* ) >= 8 )
 {
 uint64_t* mem = reinterpret_cast< uint64_t* >( data );
 uint64_t* end = mem + num_elem;
 for( ; mem < end; ++mem )
 *mem = swap_bytes( *mem );
 }
 else
 {
 uint32_t* mem = reinterpret_cast< uint32_t* >( data );
 uint32_t* end = mem + 2 * num_elem;
 for( ; mem < end; mem += 2 )
 {
 uint32_t tmp = swap_bytes( mem[0] );
 mem[0] = swap_bytes( mem[1] );
 mem[1] = tmp;
 }
 }
 }

References swap_bytes().

Referenced by byteswap().

filesize() [1/2]

long moab::SysUtil::filesize

(

FILE *

filp

)

Get size of file (if it is a regular file)

Get size of regular file.

Returns

- file size if known

• -1 if file size cannot be determined (e.g. a pipe)
• -2 if an unexpected failure occured (may indicate change in file position.)

Definition at line 27 of file SysUtil.cpp.

 {
 long curr_pos = ftell( filp );
 if( fseek( filp, 0, SEEK_END ) ) return -1;
 
 long length = ftell( filp );
 if( fseek( filp, curr_pos, SEEK_SET ) )
 {
 assert( 0 );
 return -2;
 }
 
 return length;
 }

References length().

Referenced by moab::ReadSTL::binary_read_triangles().

filesize() [2/2]

long moab::SysUtil::filesize

(

std::ifstream &

str

)

Get size of file (if it is a regular file)

Get size of regular file.

Returns

- file size if known

• -1 if file size cannot be determined (e.g. a pipe)
• -2 if an unexpected failure occured (may indicate change in file position.)

Definition at line 42 of file SysUtil.cpp.

 {
 std::istream::pos_type curr_pos = str.tellg();
 if( !str.seekg( 0, std::ios_base::end ) ) return -1;
 
 long length = static_cast< long >( str.tellg() );
 if( !str.seekg( curr_pos, std::ios_base::beg ) )
 {
 assert( 0 );
 return -2;
 }
 
 return length;
 }

References length().

little_endian()

bool moab::SysUtil::little_endian ( )

inline

Check if platform is little-endian.

Check if platform is little-endian (least significant byte at highest memory address.)

Definition at line 50 of file SysUtil.hpp.

 {
 const unsigned one = 1;
 return !*( (char*)&one );
 }

Referenced by moab::ReadSTL::binary_read_triangles(), moab::WriteSTL::binary_write_triangles(), moab::ReadSTL::load_file(), and moab::WriteSTL::write_file().

setmem()

void moab::SysUtil::setmem	(	void *	mem,
		const void *	value,
		unsigned	value_size,
		size_t	num_elem
	)

Similar to memset, but accepts values larger than 1 char.

Set block of memory to repeating copies of a sequene of bytes.

Parameters

mem	Pointer to start of memory block to initialize
value	Byte sequence to initialize mem with
value_size	Size of 'value'
num_elem	Size of 'mem' as a multiple of value_size (the number of copies of 'value' to write into 'mem'.)

Definition at line 15 of file SysUtil.cpp.

 {
 if( !num_elem ) return;
 
 char* array = reinterpret_cast< char* >( mem );
 memcpy( array, value, value_size );
 size_t count;
 for( count = 1; count * 2 < num_elem; count *= 2 )
 memcpy( array + count * value_size, array, count * value_size );
 memcpy( array + count * value_size, array, ( num_elem - count ) * value_size );
 }

Referenced by moab::DenseTag::clear_data(), moab::SequenceData::create_data(), moab::SparseTag::get_data(), moab::MeshTag::get_data(), moab::VarLenDenseTag::get_data(), moab::DenseTag::get_data(), and moab::WriteVtk::write_tag().

swap_bytes() [1/3]

static uint16_t moab::SysUtil::swap_bytes ( uint16_t  value )

inlinestatic

Definition at line 69 of file SysUtil.cpp.

 {
 return ( value >> 8 ) | ( value << 8 );
 }

Referenced by moab::ReadSTL::binary_read_triangles(), moab::WriteSTL::binary_write_triangles(), byteswap2(), byteswap4(), and byteswap8().

swap_bytes() [2/3]

static uint32_t moab::SysUtil::swap_bytes ( uint32_t  value )

inlinestatic

Definition at line 74 of file SysUtil.cpp.

 {
 return ( ( value /*& (uint32_t)0xFF000000*/ ) >> 24 ) | ( ( value & (uint32_t)0x00FF0000 ) >> 8 ) |
 ( ( value & (uint32_t)0x0000FF00 ) << 8 ) | ( ( value /*& (uint32_t)0X000000FF*/ ) << 24 );
 }

swap_bytes() [3/3]

static uint64_t moab::SysUtil::swap_bytes ( uint64_t  value )

inlinestatic

Definition at line 89 of file SysUtil.cpp.

 {
 return ( ( value /*& m64b8*/ ) >> 56 ) | ( ( value & m64b7 ) >> 40 ) | ( ( value & m64b6 ) >> 24 ) |
 ( ( value & m64b5 ) >> 8 ) | ( ( value & m64b4 ) << 8 ) | ( ( value & m64b3 ) << 24 ) |
 ( ( value & m64b2 ) << 40 ) | ( ( value /*& m64b1*/ ) << 56 );
 }

References m64b2, m64b3, m64b4, m64b5, m64b6, and m64b7.

Variable Documentation

m64b1

const uint64_t moab::SysUtil::m64b1 = 0xFF

Definition at line 80 of file SysUtil.cpp.

m64b2

const uint64_t moab::SysUtil::m64b2 = m64b1 << 8

Definition at line 81 of file SysUtil.cpp.

Referenced by swap_bytes().

m64b3

const uint64_t moab::SysUtil::m64b3 = m64b1 << 16

Definition at line 82 of file SysUtil.cpp.

Referenced by swap_bytes().

m64b4

const uint64_t moab::SysUtil::m64b4 = m64b1 << 24

Definition at line 83 of file SysUtil.cpp.

Referenced by swap_bytes().

m64b5

const uint64_t moab::SysUtil::m64b5 = m64b1 << 32

Definition at line 84 of file SysUtil.cpp.

Referenced by swap_bytes().

m64b6

const uint64_t moab::SysUtil::m64b6 = m64b1 << 40

Definition at line 85 of file SysUtil.cpp.

Referenced by swap_bytes().

m64b7

const uint64_t moab::SysUtil::m64b7 = m64b1 << 48

Definition at line 86 of file SysUtil.cpp.

Referenced by swap_bytes().