Actual source code: bread.c

petsc-3.6.4 2016-04-12
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  2: #include <petscsys.h>
  3: #include <../src/sys/classes/viewer/impls/socket/socket.h>


  6: /*
  7:    TAKEN from src/sys/fileio/sysio.c The swap byte routines are
  8:   included here because the MATLAB programs that use this do NOT
  9:   link to the PETSc libraries.
 10: */
 11: #include <errno.h>
 12: #if defined(PETSC_HAVE_UNISTD_H)
 13: #include <unistd.h>
 14: #endif

 16: #if !defined(PETSC_WORDS_BIGENDIAN)
 17: /*
 18:   SYByteSwapInt - Swap bytes in an integer
 19: */
 22: void SYByteSwapInt(int *buff,int n)
 23: {
 24:   int  i,j,tmp;
 25:   char *ptr1,*ptr2 = (char*)&tmp;
 26:   for (j=0; j<n; j++) {
 27:     ptr1 = (char*)(buff + j);
 28:     for (i=0; i<(int)sizeof(int); i++) ptr2[i] = ptr1[sizeof(int)-1-i];
 29:     buff[j] = tmp;
 30:   }
 31: }
 32: /*
 33:   SYByteSwapShort - Swap bytes in a short
 34: */
 37: void SYByteSwapShort(short *buff,int n)
 38: {
 39:   int   i,j;
 40:   short tmp;
 41:   char  *ptr1,*ptr2 = (char*)&tmp;
 42:   for (j=0; j<n; j++) {
 43:     ptr1 = (char*)(buff + j);
 44:     for (i=0; i<(int)sizeof(short); i++) ptr2[i] = ptr1[sizeof(int)-1-i];
 45:     buff[j] = tmp;
 46:   }
 47: }
 48: /*
 49:   SYByteSwapScalar - Swap bytes in a double
 50:   Complex is dealt with as if array of double twice as long.
 51: */
 54: void SYByteSwapScalar(PetscScalar *buff,int n)
 55: {
 56:   int    i,j;
 57:   double tmp,*buff1 = (double*)buff;
 58:   char   *ptr1,*ptr2 = (char*)&tmp;
 59: #if defined(PETSC_USE_COMPLEX)
 60:   n *= 2;
 61: #endif
 62:   for (j=0; j<n; j++) {
 63:     ptr1 = (char*)(buff1 + j);
 64:     for (i=0; i<(int)sizeof(double); i++) ptr2[i] = ptr1[sizeof(double)-1-i];
 65:     buff1[j] = tmp;
 66:   }
 67: }
 68: #endif

 70: #define PETSC_MEX_ERROR(a) {fprintf(stdout,"sread: %s \n",a); return PETSC_ERR_SYS;}

 74: /*
 75:     PetscBinaryRead - Reads from a socket, called from MATLAB

 77:   Input Parameters:
 78: .   fd - the file
 79: .   n  - the number of items to read
 80: .   type - the type of items to read (PETSC_INT or PETSC_SCALAR)

 82:   Output Parameters:
 83: .   p - the buffer

 85:   Notes: does byte swapping to work on all machines.
 86: */
 87: PetscErrorCode PetscBinaryRead(int fd,void *p,int n,PetscDataType type)
 88: {

 90:   int  maxblock,wsize,err;
 91:   char *pp = (char*)p;
 92: #if !defined(PETSC_WORDS_BIGENDIAN)
 93:   int  ntmp  = n;
 94:   void *ptmp = p;
 95: #endif

 97:   maxblock = 65536;
 98:   if (type == PETSC_INT)         n *= sizeof(int);
 99:   else if (type == PETSC_SCALAR) n *= sizeof(PetscScalar);
100:   else if (type == PETSC_SHORT)  n *= sizeof(short);
101:   else if (type == PETSC_CHAR)   n *= sizeof(char);
102:   else PETSC_MEX_ERROR("PetscBinaryRead: Unknown type");


105:   while (n) {
106:     wsize = (n < maxblock) ? n : maxblock;
107:     err   = read(fd,pp,wsize);
108: #if !defined(PETSC_MISSING_ERRNO_EINTR)
109:     if (err < 0 && errno == EINTR) continue;
110: #endif
111:     if (!err && wsize > 0) return 1;
112:     if (err < 0) PETSC_MEX_ERROR("Error reading from socket\n");
113:     n  -= err;
114:     pp += err;
115:   }

117: #if !defined(PETSC_WORDS_BIGENDIAN)
118:   if (type == PETSC_INT) SYByteSwapInt((int*)ptmp,ntmp);
119:   else if (type == PETSC_SCALAR) SYByteSwapScalar((PetscScalar*)ptmp,ntmp);
120:   else if (type == PETSC_SHORT) SYByteSwapShort((short*)ptmp,ntmp);
121: #endif
122:   return 0;
123: }

127: /*
128:     PetscBinaryWrite - Writes to a socket, called from MATLAB

130:   Input Parameters:
131: .   fd - the file
132: .   n  - the number of items to read
133: .   p - the data
134: .   type - the type of items to read (PETSC_INT or PETSC_SCALAR)


137:   Notes: does byte swapping to work on all machines.
138: */
139: PetscErrorCode PetscBinaryWrite(int fd,void *p,int n,PetscDataType type,PetscBool dummy)
140: {

142:   int  maxblock,wsize,err;
143:   char *pp = (char*)p;
144: #if !defined(PETSC_WORDS_BIGENDIAN)
145:   int  ntmp  = n;
146:   void *ptmp = p;
147: #endif

149:   maxblock = 65536;
150:   if (type == PETSC_INT)         n *= sizeof(int);
151:   else if (type == PETSC_SCALAR) n *= sizeof(PetscScalar);
152:   else if (type == PETSC_SHORT)  n *= sizeof(short);
153:   else if (type == PETSC_CHAR)   n *= sizeof(char);
154:   else PETSC_MEX_ERROR("PetscBinaryRead: Unknown type");

156: #if !defined(PETSC_WORDS_BIGENDIAN)
157:   /* make sure data is in correct byte ordering before sending  */
158:   if (type == PETSC_INT) SYByteSwapInt((int*)ptmp,ntmp);
159:   else if (type == PETSC_SCALAR) SYByteSwapScalar((PetscScalar*)ptmp,ntmp);
160:   else if (type == PETSC_SHORT) SYByteSwapShort((short*)ptmp,ntmp);
161: #endif

163:   while (n) {
164:     wsize = (n < maxblock) ? n : maxblock;
165:     err   = write(fd,pp,wsize);
166: #if !defined(PETSC_MISSING_ERRNO_EINTR)
167:     if (err < 0 && errno == EINTR) continue;
168: #endif
169:     if (!err && wsize > 0) return 1;
170:     if (err < 0) PETSC_MEX_ERROR("Error reading from socket\n");
171:     n  -= err;
172:     pp += err;
173:   }
174: #if !defined(PETSC_WORDS_BIGENDIAN)
175:   /* swap the data back if we swapped it before sending it */
176:   if (type == PETSC_INT) SYByteSwapInt((int*)ptmp,ntmp);
177:   else if (type == PETSC_SCALAR) SYByteSwapScalar((PetscScalar*)ptmp,ntmp);
178:   else if (type == PETSC_SHORT) SYByteSwapShort((short*)ptmp,ntmp);
179: #endif

181:   return 0;
182: }