Program: gdcm
Module: $RCSfile: gdcmUtil.cxx,v $
Language: C++
- Date: $Date: 2005/02/11 20:48:49 $
- Version: $Revision: 1.139 $
+ Date: $Date: 2005/02/14 10:43:53 $
+ Version: $Revision: 1.140 $
Copyright (c) CREATIS (Centre de Recherche et d'Applications en Traitement de
l'Image). All rights reserved. See Doc/License.txt or
/**
* \brief Provide a better 'c++' approach for sprintf
* For example c code is:
- * sprintf(trash, "%04x|%04x", group , elem);
+ * char result[200]; // hope 200 is enough
+ * sprintf(result, "%04x|%04x", group , elem);
*
* c++ code is
* std::ostringstream buf;
* buf.str();
*
* gdcm style code is
- * Format("%04x|%04x", group , elem);
+ * string result;
+ * result = gdcm::Util::Format("%04x|%04x", group , elem);
*/
std::string Util::Format(const char *format, ...)
{
/**
* \brief Because not available in C++ (?)
+ * @param str string to check
+ * @param tokens std::vector to receive the tokenized substrings
+ * @param delimiters string containing the character delimitors
+
*/
void Util::Tokenize (const std::string &str,
std::vector<std::string> &tokens,
/**
* \brief Because not available in C++ (?)
* Counts the number of occurences of a substring within a string
+ * @param str string to check
+ * @param subStr substring to count
*/
int Util::CountSubstring (const std::string &str,
const std::string &subStr)
{
- int count = 0; // counts how many times it appears
- std::string::size_type x = 0; // The index position in the string
+ int count = 0; // counts how many times it appears
+ std::string::size_type x = 0; // The index position in the string
do
{
- x = str.find(subStr,x); // Find the substring
- if (x != std::string::npos) // If present
+ x = str.find(subStr,x); // Find the substring
+ if (x != std::string::npos) // If present
{
- count++; // increase the count
- x += subStr.length(); // Skip this word
+ count++; // increase the count
+ x += subStr.length(); // Skip this word
}
}
- while (x != std::string::npos); // Carry on until not present
+ while (x != std::string::npos);// Carry on until not present
return count;
}
{
res = getlastdigit(addr);
sres.insert(sres.begin(), '0' + res);
- zero = (addr[0] == 0) && (addr[1] == 0) && (addr[2] == 0) && (addr[3] == 0) && (addr[4] == 0) && (addr[5] == 0);
+ zero = (addr[0] == 0) && (addr[1] == 0) && (addr[2] == 0)
+ && (addr[3] == 0) && (addr[4] == 0) && (addr[5] == 0);
}
return sres;
{
#if defined(GDCM_WORDS_BIGENDIAN) || defined(GDCM_FORCE_BIGENDIAN_EMULATION)
uint16_t swap;
- swap = ((( val << 8 ) & 0xff00 ) | (( val >> 8 ) & 0x00ff ) );
+ //swap = ((( val << 8 ) & 0xff00 ) | (( val >> 8 ) & 0x00ff ) );
+ //save CPU time
+ swap = ( val << 8 | val >> 8 );
+
return os.write(reinterpret_cast<const char*>(&swap), 2);
#else
return os.write(reinterpret_cast<const char*>(&val), 2);
{
#if defined(GDCM_WORDS_BIGENDIAN) || defined(GDCM_FORCE_BIGENDIAN_EMULATION)
uint32_t swap;
- swap = ( ((val<<24) & 0xff000000) | ((val<<8) & 0x00ff0000) |
- ((val>>8) & 0x0000ff00) | ((val>>24) & 0x000000ff) );
+// swap = ( ((val<<24) & 0xff000000) | ((val<<8) & 0x00ff0000) |
+// ((val>>8) & 0x0000ff00) | ((val>>24) & 0x000000ff) );
+// save CPU time
+ swap = ( (val<<24) | ((val<<8) & 0x00ff0000) |
+ ((val>>8) & 0x0000ff00) | (val>>24) );
return os.write(reinterpret_cast<const char*>(&swap), 4);
#else
return os.write(reinterpret_cast<const char*>(&val), 4);
*/
std::ostream &binary_write(std::ostream &os, const uint16_t *val, size_t len)
{
-// This is tricky since we are writting two bytes buffer. Be carefull with little endian
-// vs big endian. Also this other trick is to allocate a small (efficient) buffer that store
-// intermidiate result before writting it.
+// This is tricky since we are writting two bytes buffer.
+// Be carefull with little endian vs big endian.
+// Also this other trick is to allocate a small (efficient) buffer that store
+// intermediate result before writting it.
#if defined(GDCM_WORDS_BIGENDIAN) || defined(GDCM_FORCE_BIGENDIAN_EMULATION)
const int BUFFER_SIZE = 4096;
- uint16_t *buffer = new uint16_t[BUFFER_SIZE/2];
uint16_t *binArea16 = (uint16_t*)val;
+ uint16_t *buffer = new uint16_t[BUFFER_SIZE/2];
+ uint16_t *pbuffer = buffer;
// how many BUFFER_SIZE long pieces in binArea ?
int nbPieces = len/BUFFER_SIZE; //(16 bits = 2 Bytes)
for (int j=0;j<nbPieces;j++)
{
+
for (int i = 0; i < BUFFER_SIZE/2; i++)
{
- //buffer[i] = (binArea16[i] >> 8) | (binArea16[i] << 8);
- uint16_t val16 = binArea16[i];
- buffer[i] = ((( val16 << 8 ) & 0xff00 ) | (( val16 >> 8 ) & 0x00ff ) );
+ //uint16_t val16 = binArea16[i];
+ //buffer[i] = ((( val16 << 8 ) & 0xff00 ) | (( val16 >> 8 ) & 0x00ff ) );
+ // save CPU time :
+ // 1) Save 1 affectation and 2 AND operations
+ // buffer[i] = (binArea16[i] >> 8) | (binArea16[i] << 8);
+ // 2) Replace * operations by + operations using pointers
+ *pbuffer = *binArea16 >> 8 | *binArea16 >> 8;
+ pbuffer++;
+ binArea16++;
}
os.write ( (char*)buffer, BUFFER_SIZE );
binArea16 += BUFFER_SIZE/2;
{
for (int i = 0; i < remainingSize/2; i++)
{
- //buffer[i] = (binArea16[i] >> 8) | (binArea16[i] << 8);
- uint16_t val16 = binArea16[i];
- buffer[i] = ((( val16 << 8 ) & 0xff00 ) | (( val16 >> 8 ) & 0x00ff ) );
+ //uint16_t val16 = binArea16[i];
+ //buffer[i] = ((( val16 << 8 ) & 0xff00 ) | (( val16 >> 8 ) & 0x00ff) );
+ *pbuffer = *binArea16 >> 8 | *binArea16 >> 8;
+ pbuffer++;
+ binArea16++;
}
os.write ( (char*)buffer, remainingSize );
}
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