Date: 2026-03-31T05:46:30+00:00

Actual source code: sysio.c

      1: #include <petscsys.h>
      2: #include <petscbt.h>
      3: #include <errno.h>
      4: #include <fcntl.h>
      5: #if defined(PETSC_HAVE_UNISTD_H)
      6:   #include <unistd.h>
      7: #endif
      8: #if defined(PETSC_HAVE_IO_H)
      9:   #include <io.h>
     10: #endif
     11: #if !defined(PETSC_HAVE_O_BINARY)
     12:   #define O_BINARY 0
     13: #endif

     15: const char *const PetscFileModes[] = {"READ", "WRITE", "APPEND", "UPDATE", "APPEND_UPDATE", "PetscFileMode", "PETSC_FILE_", NULL};

     17: /*
     18:   PetscByteSwapEnum - Swap bytes in a  PETSc Enum

     20: */
     21: static PetscErrorCode PetscByteSwapEnum(PetscEnum *buff, PetscCount n)
     22: {
     23:   PetscCount i, j;
     24:   PetscEnum  tmp = ENUM_DUMMY;
     25:   char      *ptr1, *ptr2 = (char *)&tmp;

     27:   PetscFunctionBegin;
     28:   for (j = 0; j < n; j++) {
     29:     ptr1 = (char *)(buff + j);
     30:     for (i = 0; i < (PetscCount)sizeof(PetscEnum); i++) ptr2[i] = ptr1[sizeof(PetscEnum) - 1 - i];
     31:     for (i = 0; i < (PetscCount)sizeof(PetscEnum); i++) ptr1[i] = ptr2[i];
     32:   }
     33:   PetscFunctionReturn(PETSC_SUCCESS);
     34: }

     36: /*
     37:   PetscByteSwapBool - Swap bytes in a  PETSc Bool

     39: */
     40: static PetscErrorCode PetscByteSwapBool(PetscBool *buff, PetscCount n)
     41: {
     42:   PetscCount i, j;
     43:   PetscBool  tmp = PETSC_FALSE;
     44:   char      *ptr1, *ptr2 = (char *)&tmp;

     46:   PetscFunctionBegin;
     47:   for (j = 0; j < n; j++) {
     48:     ptr1 = (char *)(buff + j);
     49:     for (i = 0; i < (PetscCount)sizeof(PetscBool); i++) ptr2[i] = ptr1[sizeof(PetscBool) - 1 - i];
     50:     for (i = 0; i < (PetscCount)sizeof(PetscBool); i++) ptr1[i] = ptr2[i];
     51:   }
     52:   PetscFunctionReturn(PETSC_SUCCESS);
     53: }

     55: /*
     56:   PetscByteSwapInt - Swap bytes in a  PETSc integer (which may be 32 or 64-bits)

     58: */
     59: static PetscErrorCode PetscByteSwapInt(PetscInt *buff, PetscCount n)
     60: {
     61:   PetscCount i, j;
     62:   PetscInt   tmp = 0;
     63:   char      *ptr1, *ptr2 = (char *)&tmp;

     65:   PetscFunctionBegin;
     66:   for (j = 0; j < n; j++) {
     67:     ptr1 = (char *)(buff + j);
     68:     for (i = 0; i < (PetscCount)sizeof(PetscInt); i++) ptr2[i] = ptr1[sizeof(PetscInt) - 1 - i];
     69:     for (i = 0; i < (PetscCount)sizeof(PetscInt); i++) ptr1[i] = ptr2[i];
     70:   }
     71:   PetscFunctionReturn(PETSC_SUCCESS);
     72: }

     74: /*
     75:   PetscByteSwapInt64 - Swap bytes in a  PETSc integer (64-bits)

     77: */
     78: static PetscErrorCode PetscByteSwapInt64(PetscInt64 *buff, PetscCount n)
     79: {
     80:   PetscCount i, j;
     81:   PetscInt64 tmp = 0;
     82:   char      *ptr1, *ptr2 = (char *)&tmp;

     84:   PetscFunctionBegin;
     85:   for (j = 0; j < n; j++) {
     86:     ptr1 = (char *)(buff + j);
     87:     for (i = 0; i < (PetscCount)sizeof(PetscInt64); i++) ptr2[i] = ptr1[sizeof(PetscInt64) - 1 - i];
     88:     for (i = 0; i < (PetscCount)sizeof(PetscInt64); i++) ptr1[i] = ptr2[i];
     89:   }
     90:   PetscFunctionReturn(PETSC_SUCCESS);
     91: }

     93: /*
     94:   PetscByteSwapInt32 - Swap bytes in a  PETSc integer (32-bits)

     96: */
     97: static PetscErrorCode PetscByteSwapInt32(PetscInt32 *buff, PetscCount n)
     98: {
     99:   PetscCount i, j;
    100:   PetscInt32 tmp = 0;
    101:   char      *ptr1, *ptr2 = (char *)&tmp;

    103:   PetscFunctionBegin;
    104:   for (j = 0; j < n; j++) {
    105:     ptr1 = (char *)(buff + j);
    106:     for (i = 0; i < (PetscCount)sizeof(PetscInt32); i++) ptr2[i] = ptr1[sizeof(PetscInt32) - 1 - i];
    107:     for (i = 0; i < (PetscCount)sizeof(PetscInt32); i++) ptr1[i] = ptr2[i];
    108:   }
    109:   PetscFunctionReturn(PETSC_SUCCESS);
    110: }

    112: /*
    113:   PetscByteSwapShort - Swap bytes in a short
    114: */
    115: static PetscErrorCode PetscByteSwapShort(short *buff, PetscCount n)
    116: {
    117:   PetscCount i, j;
    118:   short      tmp;
    119:   char      *ptr1, *ptr2 = (char *)&tmp;

    121:   PetscFunctionBegin;
    122:   for (j = 0; j < n; j++) {
    123:     ptr1 = (char *)(buff + j);
    124:     for (i = 0; i < (PetscCount)sizeof(short); i++) ptr2[i] = ptr1[sizeof(short) - 1 - i];
    125:     for (i = 0; i < (PetscCount)sizeof(short); i++) ptr1[i] = ptr2[i];
    126:   }
    127:   PetscFunctionReturn(PETSC_SUCCESS);
    128: }
    129: /*
    130:   PetscByteSwapLong - Swap bytes in a long
    131: */
    132: static PetscErrorCode PetscByteSwapLong(long *buff, PetscCount n)
    133: {
    134:   PetscCount i, j;
    135:   long       tmp;
    136:   char      *ptr1, *ptr2 = (char *)&tmp;

    138:   PetscFunctionBegin;
    139:   for (j = 0; j < n; j++) {
    140:     ptr1 = (char *)(buff + j);
    141:     for (i = 0; i < (PetscCount)sizeof(long); i++) ptr2[i] = ptr1[sizeof(long) - 1 - i];
    142:     for (i = 0; i < (PetscCount)sizeof(long); i++) ptr1[i] = ptr2[i];
    143:   }
    144:   PetscFunctionReturn(PETSC_SUCCESS);
    145: }

    147: /*
    148:   PetscByteSwapReal - Swap bytes in a PetscReal
    149: */
    150: static PetscErrorCode PetscByteSwapReal(PetscReal *buff, PetscCount n)
    151: {
    152:   PetscCount i, j;
    153:   PetscReal  tmp, *buff1 = buff;
    154:   char      *ptr1, *ptr2 = (char *)&tmp;

    156:   PetscFunctionBegin;
    157:   for (j = 0; j < n; j++) {
    158:     ptr1 = (char *)(buff1 + j);
    159:     for (i = 0; i < (PetscCount)sizeof(PetscReal); i++) ptr2[i] = ptr1[sizeof(PetscReal) - 1 - i];
    160:     for (i = 0; i < (PetscCount)sizeof(PetscReal); i++) ptr1[i] = ptr2[i];
    161:   }
    162:   PetscFunctionReturn(PETSC_SUCCESS);
    163: }

    165: /*
    166:   PetscByteSwapScalar - Swap bytes in a PetscScalar
    167:   The complex case is dealt with an array of PetscReal, twice as long.
    168: */
    169: static PetscErrorCode PetscByteSwapScalar(PetscScalar *buff, PetscCount n)
    170: {
    171:   PetscCount i, j;
    172: #if defined(PETSC_USE_COMPLEX)
    173:   PetscReal tmp, *buff1 = (PetscReal *)buff;
    174: #else
    175:   PetscReal tmp, *buff1 = buff;
    176: #endif
    177:   char *ptr1, *ptr2 = (char *)&tmp;

    179:   PetscFunctionBegin;
    180: #if defined(PETSC_USE_COMPLEX)
    181:   n *= 2;
    182: #endif
    183:   for (j = 0; j < n; j++) {
    184:     ptr1 = (char *)(buff1 + j);
    185:     for (i = 0; i < (PetscCount)sizeof(PetscReal); i++) ptr2[i] = ptr1[sizeof(PetscReal) - 1 - i];
    186:     for (i = 0; i < (PetscCount)sizeof(PetscReal); i++) ptr1[i] = ptr2[i];
    187:   }
    188:   PetscFunctionReturn(PETSC_SUCCESS);
    189: }

    191: /*
    192:   PetscByteSwapDouble - Swap bytes in a double
    193: */
    194: static PetscErrorCode PetscByteSwapDouble(double *buff, PetscCount n)
    195: {
    196:   PetscCount i, j;
    197:   double     tmp, *buff1 = buff;
    198:   char      *ptr1, *ptr2 = (char *)&tmp;

    200:   PetscFunctionBegin;
    201:   for (j = 0; j < n; j++) {
    202:     ptr1 = (char *)(buff1 + j);
    203:     for (i = 0; i < (PetscCount)sizeof(double); i++) ptr2[i] = ptr1[sizeof(double) - 1 - i];
    204:     for (i = 0; i < (PetscCount)sizeof(double); i++) ptr1[i] = ptr2[i];
    205:   }
    206:   PetscFunctionReturn(PETSC_SUCCESS);
    207: }

    209: /*
    210:   PetscByteSwapFloat - Swap bytes in a float
    211: */
    212: static PetscErrorCode PetscByteSwapFloat(float *buff, PetscCount n)
    213: {
    214:   PetscCount i, j;
    215:   float      tmp, *buff1 = buff;
    216:   char      *ptr1, *ptr2 = (char *)&tmp;

    218:   PetscFunctionBegin;
    219:   for (j = 0; j < n; j++) {
    220:     ptr1 = (char *)(buff1 + j);
    221:     for (i = 0; i < (PetscCount)sizeof(float); i++) ptr2[i] = ptr1[sizeof(float) - 1 - i];
    222:     for (i = 0; i < (PetscCount)sizeof(float); i++) ptr1[i] = ptr2[i];
    223:   }
    224:   PetscFunctionReturn(PETSC_SUCCESS);
    225: }

    227: PetscErrorCode PetscByteSwap(void *data, PetscDataType pdtype, PetscCount count)
    228: {
    229:   PetscFunctionBegin;
    230:   if (pdtype == PETSC_INT) PetscCall(PetscByteSwapInt((PetscInt *)data, count));
    231:   else if (pdtype == PETSC_ENUM) PetscCall(PetscByteSwapEnum((PetscEnum *)data, count));
    232:   else if (pdtype == PETSC_BOOL) PetscCall(PetscByteSwapBool((PetscBool *)data, count));
    233:   else if (pdtype == PETSC_SCALAR) PetscCall(PetscByteSwapScalar((PetscScalar *)data, count));
    234:   else if (pdtype == PETSC_REAL) PetscCall(PetscByteSwapReal((PetscReal *)data, count));
    235:   else if (pdtype == PETSC_COMPLEX) PetscCall(PetscByteSwapReal((PetscReal *)data, 2 * count));
    236:   else if (pdtype == PETSC_INT64) PetscCall(PetscByteSwapInt64((PetscInt64 *)data, count));
    237:   else if (pdtype == PETSC_COUNT) PetscCall(PetscByteSwapInt64((PetscInt64 *)data, count));
    238:   else if (pdtype == PETSC_INT32) PetscCall(PetscByteSwapInt32((PetscInt32 *)data, count));
    239:   else if (pdtype == PETSC_DOUBLE) PetscCall(PetscByteSwapDouble((double *)data, count));
    240:   else if (pdtype == PETSC_FLOAT) PetscCall(PetscByteSwapFloat((float *)data, count));
    241:   else if (pdtype == PETSC_SHORT) PetscCall(PetscByteSwapShort((short *)data, count));
    242:   else if (pdtype == PETSC_LONG) PetscCall(PetscByteSwapLong((long *)data, count));
    243:   else if (pdtype == PETSC_CHAR) PetscFunctionReturn(PETSC_SUCCESS);
    244:   else SETERRQ(PETSC_COMM_SELF, PETSC_ERR_ARG_OUTOFRANGE, "Unknown type: %d", pdtype);
    245:   PetscFunctionReturn(PETSC_SUCCESS);
    246: }

    248: /*@C
    249:   PetscBinaryRead - Reads from a binary file.

    251:   Not Collective

    253:   Input Parameters:
    254: + fd   - the file descriptor
    255: . num  - the maximum number of items to read
    256: - type - the type of items to read (`PETSC_INT`, `PETSC_REAL`, `PETSC_SCALAR`, etc.)

    258:   Output Parameters:
    259: + data  - the buffer, this is an array of the type that matches the value in `type`
    260: - count - the number of items read, optional

    262:   Level: developer

    264:   Notes:
    265:   If `count` is not provided and the number of items read is less than
    266:   the maximum number of items to read, then this routine errors.

    268:   `PetscBinaryRead()` uses byte swapping to work on all machines; the files
    269:   are written ALWAYS using big-endian ordering. On little-endian machines the numbers
    270:   are converted to the little-endian format when they are read in from the file.
    271:   When PETSc is ./configure with `--with-64-bit-indices` the integers are written to the
    272:   file as 64-bit integers, this means they can only be read back in when the option `--with-64-bit-indices`
    273:   is used.

    275:   Fortran Note:
    276:   There are different functions for each datatype, for example `PetscBinaryReadInt()`

    278: .seealso: `PetscBinaryWrite()`, `PetscBinaryOpen()`, `PetscBinaryClose()`, `PetscViewerBinaryGetDescriptor()`, `PetscBinarySynchronizedWrite()`,
    279:           `PetscBinarySynchronizedRead()`, `PetscBinarySynchronizedSeek()`
    280: @*/
    281: PetscErrorCode PetscBinaryRead(int fd, void *data, PetscCount num, PetscInt *count, PetscDataType type)
    282: {
    283:   size_t typesize, m = (size_t)num, n = 0, maxblock = 65536;
    284:   char  *p = (char *)data;
    285: #if defined(PETSC_USE_REAL___FLOAT128)
    286:   PetscBool readdouble = PETSC_FALSE;
    287:   double   *pdouble;
    288: #endif
    289:   void *ptmp  = data;
    290:   char *fname = NULL;

    292:   PetscFunctionBegin;
    293:   if (count) *count = 0;
    294:   PetscCheck(num >= 0, PETSC_COMM_SELF, PETSC_ERR_ARG_OUTOFRANGE, "Trying to read a negative amount of data %" PetscCount_FMT, num);
    295:   if (!num) PetscFunctionReturn(PETSC_SUCCESS);

    297:   if (type == PETSC_FUNCTION) {
    298:     m     = 64;
    299:     type  = PETSC_CHAR;
    300:     fname = (char *)malloc(m * sizeof(char));
    301:     p     = fname;
    302:     ptmp  = (void *)fname;
    303:     PetscCheck(fname, PETSC_COMM_SELF, PETSC_ERR_MEM, "Cannot allocate space for function name");
    304:   }
    305:   if (type == PETSC_BIT_LOGICAL) m = PetscBTLength(num);

    307:   PetscCall(PetscDataTypeGetSize(type, &typesize));

    309: #if defined(PETSC_USE_REAL___FLOAT128)
    310:   PetscCall(PetscOptionsGetBool(NULL, NULL, "-binary_read_double", &readdouble, NULL));
    311:   /* If using __float128 precision we still read in doubles from file */
    312:   if ((type == PETSC_REAL || type == PETSC_COMPLEX) && readdouble) {
    313:     PetscInt cnt = num * ((type == PETSC_REAL) ? 1 : 2);
    314:     PetscCall(PetscMalloc1(cnt, &pdouble));
    315:     p = (char *)pdouble;
    316:     typesize /= 2;
    317:   }
    318: #endif

    320:   m *= typesize;

    322:   while (m) {
    323:     size_t len = (m < maxblock) ? m : maxblock;
    324:     int    ret = (int)read(fd, p, len);
    325:     if (ret < 0 && errno == EINTR) continue;
    326:     if (!ret && len > 0) break; /* Proxy for EOF */
    327:     PetscCheck(ret >= 0, PETSC_COMM_SELF, PETSC_ERR_FILE_READ, "Error reading from file due to \"%s\"", strerror(errno));
    328:     m -= (size_t)ret;
    329:     p += ret;
    330:     n += (size_t)ret;
    331:   }
    332:   PetscCheck(!m || count, PETSC_COMM_SELF, PETSC_ERR_FILE_READ, "Read past end of file");

    334:   num = n / typesize;                             /* Should we require `n % typesize == 0` ? */
    335:   if (count) PetscCall(PetscIntCast(num, count)); /* TODO: This is most likely wrong for PETSC_BIT_LOGICAL */

    337: #if defined(PETSC_USE_REAL___FLOAT128)
    338:   if ((type == PETSC_REAL || type == PETSC_COMPLEX) && readdouble) {
    339:     PetscInt   i, cnt = num * ((type == PETSC_REAL) ? 1 : 2);
    340:     PetscReal *preal = (PetscReal *)data;
    341:     if (!PetscBinaryBigEndian()) PetscCall(PetscByteSwapDouble(pdouble, cnt));
    342:     for (i = 0; i < cnt; i++) preal[i] = pdouble[i];
    343:     PetscCall(PetscFree(pdouble));
    344:     PetscFunctionReturn(PETSC_SUCCESS);
    345:   }
    346: #endif

    348:   if (!PetscBinaryBigEndian()) PetscCall(PetscByteSwap(ptmp, type, num));

    350:   if (type == PETSC_FUNCTION) {
    351: #if defined(PETSC_SERIALIZE_FUNCTIONS)
    352:     PetscCall(PetscDLSym(NULL, fname, (void **)data));
    353: #else
    354:     *(void **)data = NULL;
    355: #endif
    356:     free(fname);
    357:   }
    358:   PetscFunctionReturn(PETSC_SUCCESS);
    359: }

    361: /*@C
    362:   PetscBinaryWrite - Writes to a binary file.

    364:   Not Collective

    366:   Input Parameters:
    367: + fd   - the file
    368: . p    - the buffer, an array of the type that matches the value in `type`
    369: . n    - the number of items to write
    370: - type - the type of items to read (`PETSC_INT`, `PETSC_REAL` or `PETSC_SCALAR`)

    372:   Level: advanced

    374:   Notes:
    375:   `PetscBinaryWrite()` uses byte swapping to work on all machines; the files
    376:   are written using big-endian ordering to the file. On little-endian machines the numbers
    377:   are converted to the big-endian format when they are written to disk.
    378:   When PETSc is configured using `./configure with --with-64-bit-indices` the integers are written to the
    379:   file as 64-bit integers, this means they can only be read back in when the option `--with-64-bit-indices`
    380:   is used.

    382:   If running with `__float128` precision the output of `PETSC_REAL` is in `__float128` unless one uses the `-binary_write_double` option

    384:   The buffer `p` should be read-write buffer, and not static data.
    385:   This way, byte-swapping is done in-place, and then the buffer is
    386:   written to the file.

    388:   This routine restores the original contents of the buffer, after
    389:   it is written to the file. This is done by byte-swapping in-place
    390:   the second time.

    392:   Because byte-swapping may be done on the values in data it cannot be declared const

    394:   Fortran Note:
    395:   There are different functions for each datatype, for example `PetscBinaryWriteInt()`

    397: .seealso: `PetscBinaryRead()`, `PetscBinaryOpen()`, `PetscBinaryClose()`, `PetscViewerBinaryGetDescriptor()`, `PetscBinarySynchronizedWrite()`,
    398:           `PetscBinarySynchronizedRead()`, `PetscBinarySynchronizedSeek()`
    399: @*/
    400: PetscErrorCode PetscBinaryWrite(int fd, const void *p, PetscCount n, PetscDataType type)
    401: {
    402:   const char  *pp = (char *)p;
    403:   size_t       err, m = (size_t)n, wsize;
    404:   const size_t maxblock = 65536;
    405:   const void  *ptmp     = p;
    406:   char        *fname    = NULL;
    407: #if defined(PETSC_USE_REAL___FLOAT128)
    408:   PetscBool  writedouble = PETSC_FALSE;
    409:   double    *ppp;
    410:   PetscReal *pv;
    411: #endif
    412:   PetscDataType wtype = type;

    414:   PetscFunctionBegin;
    415:   PetscCheck(n >= 0, PETSC_COMM_SELF, PETSC_ERR_ARG_OUTOFRANGE, "Trying to write a negative amount of data %" PetscCount_FMT, n);
    416:   if (!n) PetscFunctionReturn(PETSC_SUCCESS);

    418:   if (type == PETSC_FUNCTION) {
    419: #if defined(PETSC_SERIALIZE_FUNCTIONS)
    420:     const char *fnametmp;
    421: #endif
    422:     m     = 64;
    423:     fname = (char *)malloc(m * sizeof(char));
    424:     PetscCheck(fname, PETSC_COMM_SELF, PETSC_ERR_MEM, "Cannot allocate space for function name");
    425: #if defined(PETSC_SERIALIZE_FUNCTIONS)
    426:     PetscCheck(n <= 1, PETSC_COMM_SELF, PETSC_ERR_SUP, "Can only binary view a single function at a time");
    427:     PetscCall(PetscFPTFind(*(void **)p, &fnametmp));
    428:     PetscCall(PetscStrncpy(fname, fnametmp, m));
    429: #else
    430:     PetscCall(PetscStrncpy(fname, "", m));
    431: #endif
    432:     wtype = PETSC_CHAR;
    433:     pp    = fname;
    434:     ptmp  = (void *)fname;
    435:   }

    437: #if defined(PETSC_USE_REAL___FLOAT128)
    438:   PetscCall(PetscOptionsGetBool(NULL, NULL, "-binary_write_double", &writedouble, NULL));
    439:   /* If using __float128 precision we still write in doubles to file */
    440:   if ((type == PETSC_SCALAR || type == PETSC_REAL || type == PETSC_COMPLEX) && writedouble) {
    441:     wtype = PETSC_DOUBLE;
    442:     PetscCall(PetscMalloc1(n, &ppp));
    443:     pv = (PetscReal *)pp;
    444:     for (PetscCount i = 0; i < n; i++) ppp[i] = (double)pv[i];
    445:     pp   = (char *)ppp;
    446:     ptmp = (char *)ppp;
    447:   }
    448: #endif

    450:   if (wtype == PETSC_INT) m *= sizeof(PetscInt);
    451:   else if (wtype == PETSC_SCALAR) m *= sizeof(PetscScalar);
    452: #if defined(PETSC_HAVE_COMPLEX)
    453:   else if (wtype == PETSC_COMPLEX) m *= sizeof(PetscComplex);
    454: #endif
    455:   else if (wtype == PETSC_REAL) m *= sizeof(PetscReal);
    456:   else if (wtype == PETSC_DOUBLE) m *= sizeof(double);
    457:   else if (wtype == PETSC_FLOAT) m *= sizeof(float);
    458:   else if (wtype == PETSC_SHORT) m *= sizeof(short);
    459:   else if (wtype == PETSC_LONG) m *= sizeof(long);
    460:   else if (wtype == PETSC_CHAR) m *= sizeof(char);
    461:   else if (wtype == PETSC_ENUM) m *= sizeof(PetscEnum);
    462:   else if (wtype == PETSC_BOOL) m *= sizeof(PetscBool);
    463:   else if (wtype == PETSC_INT64) m *= sizeof(PetscInt64);
    464:   else if (wtype == PETSC_INT32) m *= sizeof(PetscInt32);
    465:   else if (wtype == PETSC_BIT_LOGICAL) m = PetscBTLength(m) * sizeof(char);
    466:   else SETERRQ(PETSC_COMM_SELF, PETSC_ERR_ARG_OUTOFRANGE, "Unknown type: %d", wtype);

    468:   if (!PetscBinaryBigEndian()) PetscCall(PetscByteSwap((void *)ptmp, wtype, n));

    470:   while (m) {
    471:     wsize = (m < maxblock) ? m : maxblock;
    472:     err   = (size_t)write(fd, pp, wsize);
    473:     if (errno == EINTR) continue;
    474:     PetscCheck(err == wsize, PETSC_COMM_SELF, PETSC_ERR_FILE_WRITE, "Error writing to file total size %d err %d wsize %d due to \"%s\"", (int)n, (int)err, (int)wsize, strerror(errno));
    475:     m -= wsize;
    476:     pp += wsize;
    477:   }

    479:   if (!PetscBinaryBigEndian()) PetscCall(PetscByteSwap((void *)ptmp, wtype, n));

    481:   if (type == PETSC_FUNCTION) free(fname);
    482: #if defined(PETSC_USE_REAL___FLOAT128)
    483:   if ((type == PETSC_SCALAR || type == PETSC_REAL || type == PETSC_COMPLEX) && writedouble) PetscCall(PetscFree(ppp));
    484: #endif
    485:   PetscFunctionReturn(PETSC_SUCCESS);
    486: }

    488: /*@
    489:   PetscBinaryOpen - Opens a PETSc binary file.

    491:   Not Collective

    493:   Input Parameters:
    494: + name - filename
    495: - mode - open mode of binary file, one of `FILE_MODE_READ`, `FILE_MODE_WRITE`, `FILE_MODE_APPEND`

    497:   Output Parameter:
    498: . fd - the file

    500:   Level: advanced

    502: .seealso: `PetscBinaryRead()`, `PetscBinaryWrite()`, `PetscFileMode`, `PetscViewerFileSetMode()`, `PetscViewerBinaryGetDescriptor()`,
    503:           `PetscBinarySynchronizedWrite()`, `PetscBinarySynchronizedRead()`, `PetscBinarySynchronizedSeek()`
    504: @*/
    505: PetscErrorCode PetscBinaryOpen(const char name[], PetscFileMode mode, int *fd)
    506: {
    507:   PetscFunctionBegin;
    508:   switch (mode) {
    509:   case FILE_MODE_READ:
    510:     *fd = open(name, O_BINARY | O_RDONLY, 0);
    511:     break;
    512:   case FILE_MODE_WRITE:
    513:     *fd = open(name, O_BINARY | O_WRONLY | O_CREAT | O_TRUNC, 0666);
    514:     break;
    515:   case FILE_MODE_APPEND:
    516:     *fd = open(name, O_BINARY | O_WRONLY | O_APPEND, 0);
    517:     break;
    518:   default:
    519:     SETERRQ(PETSC_COMM_SELF, PETSC_ERR_SUP, "Unsupported file mode %s", PetscFileModes[mode]);
    520:   }
    521:   PetscCheck(*fd != -1, PETSC_COMM_SELF, PETSC_ERR_FILE_OPEN, "Cannot open file %s for %s due to \"%s\"", name, PetscFileModes[mode], strerror(errno));
    522:   PetscFunctionReturn(PETSC_SUCCESS);
    523: }

    525: /*@
    526:   PetscBinaryClose - Closes a PETSc binary file.

    528:   Not Collective

    530:   Output Parameter:
    531: . fd - the file

    533:   Level: advanced

    535: .seealso: `PetscBinaryRead()`, `PetscBinaryWrite()`, `PetscBinaryOpen()`, `PetscBinarySynchronizedWrite()`, `PetscBinarySynchronizedRead()`,
    536:           `PetscBinarySynchronizedSeek()`
    537: @*/
    538: PetscErrorCode PetscBinaryClose(int fd)
    539: {
    540:   PetscFunctionBegin;
    541:   PetscCheck(!close(fd), PETSC_COMM_SELF, PETSC_ERR_SYS, "close() failed on file descriptor");
    542:   PetscFunctionReturn(PETSC_SUCCESS);
    543: }

    545: /*@C
    546:   PetscBinarySeek - Moves the file pointer on a PETSc binary file.

    548:   Not Collective, No Fortran Support

    550:   Input Parameters:
    551: + fd     - the file
    552: . off    - number of bytes to move. Use `PETSC_BINARY_INT_SIZE`, `PETSC_BINARY_SCALAR_SIZE`,
    553:            etc. in your calculation rather than `sizeof()` to compute byte lengths.
    554: - whence - see `PetscBinarySeekType` for possible values

    556:   Output Parameter:
    557: . offset - new offset in file

    559:   Level: developer

    561: .seealso: `PetscBinaryRead()`, `PetscBinarySeekType`, `PetscBinaryWrite()`, `PetscBinaryOpen()`, `PetscBinarySynchronizedWrite()`, `PetscBinarySynchronizedRead()`,
    562:           `PetscBinarySynchronizedSeek()`
    563: @*/
    564: PetscErrorCode PetscBinarySeek(int fd, off_t off, PetscBinarySeekType whence, off_t *offset)
    565: {
    566:   int iwhence = 0;

    568:   PetscFunctionBegin;
    569:   if (whence == PETSC_BINARY_SEEK_SET) iwhence = SEEK_SET;
    570:   else if (whence == PETSC_BINARY_SEEK_CUR) iwhence = SEEK_CUR;
    571:   else if (whence == PETSC_BINARY_SEEK_END) iwhence = SEEK_END;
    572:   else SETERRQ(PETSC_COMM_SELF, PETSC_ERR_ARG_OUTOFRANGE, "Unknown seek location");
    573: #if defined(PETSC_HAVE_LSEEK)
    574:   *offset = lseek(fd, off, iwhence);
    575: #elif defined(PETSC_HAVE__LSEEK)
    576:   *offset = _lseek(fd, (long)off, iwhence);
    577: #else
    578:   SETERRQ(PETSC_COMM_SELF, PETSC_ERR_SUP_SYS, "System does not have a way of seeking on a file");
    579: #endif
    580:   PetscFunctionReturn(PETSC_SUCCESS);
    581: }

    583: /*@C
    584:   PetscBinarySynchronizedRead - Reads from a binary file, all MPI processes get the same values

    586:   Collective, No Fortran Support

    588:   Input Parameters:
    589: + comm - the MPI communicator
    590: . fd   - the file descriptor
    591: . num  - the maximum number of items to read
    592: - type - the type of items to read (`PETSC_INT`, `PETSC_REAL`, `PETSC_SCALAR`, etc.)

    594:   Output Parameters:
    595: + data  - the buffer, an array of the type that matches the value in `type`
    596: - count - the number of items read, optional

    598:   Level: developer

    600:   Notes:
    601:   Does a `PetscBinaryRead()` followed by an `MPI_Bcast()`

    603:   If `count` is not provided and the number of items read is less than
    604:   the maximum number of items to read, then this routine errors.

    606:   `PetscBinarySynchronizedRead()` uses byte swapping to work on all machines.
    607:   The files  are written using big-endian ordering to the file. On little-endian machines the numbers
    608:   are converted to the big-endian format when they are written to disk.
    609:   When PETSc is configured using `./configure with --with-64-bit-indices` the integers are written to the
    610:   file as 64-bit integers, this means they can only be read back in when the option `--with-64-bit-indices`
    611:   is used.

    613: .seealso: `PetscBinaryWrite()`, `PetscBinaryOpen()`, `PetscBinaryClose()`, `PetscBinaryRead()`, `PetscBinarySynchronizedWrite()`,
    614:           `PetscBinarySynchronizedSeek()`
    615: @*/
    616: PetscErrorCode PetscBinarySynchronizedRead(MPI_Comm comm, int fd, void *data, PetscInt num, PetscInt *count, PetscDataType type)
    617: {
    618:   PetscMPIInt  rank, size;
    619:   MPI_Datatype mtype;
    620:   PetscInt     ibuf[2] = {0, 0};
    621:   char        *fname   = NULL;
    622:   void        *fptr    = NULL;

    624:   PetscFunctionBegin;
    625:   if (type == PETSC_FUNCTION) {
    626:     num   = 64;
    627:     type  = PETSC_CHAR;
    628:     fname = (char *)malloc(num * sizeof(char));
    629:     fptr  = data;
    630:     data  = (void *)fname;
    631:     PetscCheck(fname, PETSC_COMM_SELF, PETSC_ERR_MEM, "Cannot allocate space for function name");
    632:   }

    634:   PetscCallMPI(MPI_Comm_rank(comm, &rank));
    635:   PetscCallMPI(MPI_Comm_size(comm, &size));
    636:   if (rank == 0) ibuf[0] = (PetscInt)PetscBinaryRead(fd, data, num, count ? &ibuf[1] : NULL, type);
    637:   PetscCallMPI(MPI_Bcast(ibuf, 2, MPIU_INT, 0, comm));
    638:   PetscCall((PetscErrorCode)ibuf[0]);

    640:   /* skip MPI call on potentially huge amounts of data when running with one process; this allows the amount of data to basically unlimited in that case */
    641:   if (size > 1) {
    642:     PetscMPIInt cnt;

    644:     PetscCall(PetscMPIIntCast(count ? ibuf[1] : num, &cnt));
    645:     PetscCall(PetscDataTypeToMPIDataType(type, &mtype));
    646:     PetscCallMPI(MPI_Bcast(data, cnt, mtype, 0, comm));
    647:   }
    648:   if (count) *count = ibuf[1];

    650:   if (type == PETSC_FUNCTION) {
    651: #if defined(PETSC_SERIALIZE_FUNCTIONS)
    652:     PetscCall(PetscDLLibrarySym(PETSC_COMM_SELF, &PetscDLLibrariesLoaded, NULL, fname, (void **)fptr));
    653: #else
    654:     *(void **)fptr = NULL;
    655: #endif
    656:     free(fname);
    657:   }
    658:   PetscFunctionReturn(PETSC_SUCCESS);
    659: }

    661: /*@C
    662:   PetscBinarySynchronizedWrite - writes to a binary file.

    664:   Collective, No Fortran Support

    666:   Input Parameters:
    667: + comm - the MPI communicator
    668: . fd   - the file
    669: . n    - the number of items to write
    670: . p    - the buffer, an array of the type that matches the value in `type`
    671: - type - the type of items to write (`PETSC_INT`, `PETSC_REAL` or `PETSC_SCALAR`)

    673:   Level: developer

    675:   Notes:
    676:   MPI rank 0 does a `PetscBinaryWrite()` the values on other MPI processes are not used

    678:   The files  are written using big-endian ordering to the file. On little-endian machines the numbers
    679:   are converted to the big-endian format when they are written to disk.
    680:   When PETSc is configured using `./configure with --with-64-bit-indices` the integers are written to the
    681:   file as 64-bit integers, this means they can only be read back in when the option `--with-64-bit-indices`
    682:   is used.

    684:   Because byte-swapping may be done on the values in data it cannot be declared const

    686:   This is NOT like `PetscSynchronizedFPrintf()`! This routine ignores calls on all but MPI rank 0,
    687:   while `PetscSynchronizedFPrintf()` has all MPI processes print their strings in order.

    689: .seealso: `PetscBinaryWrite()`, `PetscBinaryOpen()`, `PetscBinaryClose()`, `PetscBinaryRead()`, `PetscBinarySynchronizedRead()`,
    690:           `PetscBinarySynchronizedSeek()`
    691: @*/
    692: PetscErrorCode PetscBinarySynchronizedWrite(MPI_Comm comm, int fd, const void *p, PetscInt n, PetscDataType type)
    693: {
    694:   PetscMPIInt rank;

    696:   PetscFunctionBegin;
    697:   PetscCallMPI(MPI_Comm_rank(comm, &rank));
    698:   if (rank == 0) PetscCall(PetscBinaryWrite(fd, p, n, type));
    699:   PetscFunctionReturn(PETSC_SUCCESS);
    700: }

    702: /*@C
    703:   PetscBinarySynchronizedSeek - Moves the file pointer on a PETSc binary file.

    705:   No Fortran Support

    707:   Input Parameters:
    708: + comm   - the communicator to read with
    709: . fd     - the file
    710: . whence - see `PetscBinarySeekType` for possible values
    711: - off    - number of bytes to move. Use `PETSC_BINARY_INT_SIZE`, `PETSC_BINARY_SCALAR_SIZE`,
    712:             etc. in your calculation rather than `sizeof()` to compute byte lengths.

    714:   Output Parameter:
    715: . offset - new offset in file

    717:   Level: developer

    719: .seealso: `PetscBinaryRead()`, `PetscBinarySeekType`, `PetscBinaryWrite()`, `PetscBinaryOpen()`, `PetscBinarySynchronizedWrite()`, `PetscBinarySynchronizedRead()`,

    721: @*/
    722: PetscErrorCode PetscBinarySynchronizedSeek(MPI_Comm comm, int fd, off_t off, PetscBinarySeekType whence, off_t *offset)
    723: {
    724:   PetscMPIInt rank;

    726:   PetscFunctionBegin;
    727:   PetscCallMPI(MPI_Comm_rank(comm, &rank));
    728:   if (rank == 0) PetscCall(PetscBinarySeek(fd, off, whence, offset));
    729:   PetscFunctionReturn(PETSC_SUCCESS);
    730: }

    732: #if defined(PETSC_HAVE_MPIIO)

    734:   #if defined(PETSC_USE_PETSC_MPI_EXTERNAL32)
    735: /*
    736:       MPICH does not provide the external32 representation for MPI_File_set_view() so we need to provide the functions.
    737:     These are set into MPI in PetscInitialize() via MPI_Register_datarep()

    739:     Note I use PetscMPIInt for the MPI error codes since that is what MPI uses (instead of the standard PetscErrorCode)

    741:     The next three routines are not used because MPICH does not support their use

    743: */
    744: PETSC_EXTERN PetscMPIInt PetscDataRep_extent_fn(MPI_Datatype datatype, MPI_Aint *file_extent, void *extra_state)
    745: {
    746:   MPI_Aint    ub;
    747:   PetscMPIInt ierr;

    749:   ierr = MPI_Type_get_extent(datatype, &ub, file_extent);
    750:   return ierr;
    751: }

    753: PETSC_EXTERN PetscMPIInt PetscDataRep_read_conv_fn(void *userbuf, MPI_Datatype datatype, PetscMPIInt count, void *filebuf, MPI_Offset position, void *extra_state)
    754: {
    755:   PetscDataType pdtype;
    756:   PetscMPIInt   ierr;
    757:   size_t        dsize;

    759:   PetscCall(PetscMPIDataTypeToPetscDataType(datatype, &pdtype));
    760:   PetscCall(PetscDataTypeGetSize(pdtype, &dsize));

    762:   /* offset is given in units of MPI_Datatype */
    763:   userbuf = ((char *)userbuf) + dsize * position;

    765:   PetscCall(PetscMemcpy(userbuf, filebuf, count * dsize));
    766:   if (!PetscBinaryBigEndian()) PetscCall(PetscByteSwap(userbuf, pdtype, count));
    767:   return ierr;
    768: }

    770: PetscMPIInt PetscDataRep_write_conv_fn(void *userbuf, MPI_Datatype datatype, PetscMPIInt count, void *filebuf, MPI_Offset position, void *extra_state)
    771: {
    772:   PetscDataType pdtype;
    773:   PetscMPIInt   ierr;
    774:   size_t        dsize;

    776:   PetscCall(PetscMPIDataTypeToPetscDataType(datatype, &pdtype));
    777:   PetscCall(PetscDataTypeGetSize(pdtype, &dsize));

    779:   /* offset is given in units of MPI_Datatype */
    780:   userbuf = ((char *)userbuf) + dsize * position;

    782:   PetscCall(PetscMemcpy(filebuf, userbuf, count * dsize));
    783:   if (!PetscBinaryBigEndian()) PetscCall(PetscByteSwap(filebuf, pdtype, count));
    784:   return ierr;
    785: }
    786:   #endif

    788: PetscErrorCode MPIU_File_write_all(MPI_File fd, void *data, PetscMPIInt cnt, MPI_Datatype dtype, MPI_Status *status)
    789: {
    790:   PetscDataType pdtype;

    792:   PetscFunctionBegin;
    793:   PetscCall(PetscMPIDataTypeToPetscDataType(dtype, &pdtype));
    794:   if (!PetscBinaryBigEndian()) PetscCall(PetscByteSwap(data, pdtype, cnt));
    795:   PetscCallMPI(MPI_File_write_all(fd, data, cnt, dtype, status));
    796:   if (!PetscBinaryBigEndian()) PetscCall(PetscByteSwap(data, pdtype, cnt));
    797:   PetscFunctionReturn(PETSC_SUCCESS);
    798: }

    800: PetscErrorCode MPIU_File_read_all(MPI_File fd, void *data, PetscMPIInt cnt, MPI_Datatype dtype, MPI_Status *status)
    801: {
    802:   PetscDataType pdtype;

    804:   PetscFunctionBegin;
    805:   PetscCall(PetscMPIDataTypeToPetscDataType(dtype, &pdtype));
    806:   PetscCallMPI(MPI_File_read_all(fd, data, cnt, dtype, status));
    807:   if (!PetscBinaryBigEndian()) PetscCall(PetscByteSwap(data, pdtype, cnt));
    808:   PetscFunctionReturn(PETSC_SUCCESS);
    809: }

    811: PetscErrorCode MPIU_File_write_at(MPI_File fd, MPI_Offset off, void *data, PetscMPIInt cnt, MPI_Datatype dtype, MPI_Status *status)
    812: {
    813:   PetscDataType pdtype;

    815:   PetscFunctionBegin;
    816:   PetscCall(PetscMPIDataTypeToPetscDataType(dtype, &pdtype));
    817:   if (!PetscBinaryBigEndian()) PetscCall(PetscByteSwap(data, pdtype, cnt));
    818:   PetscCallMPI(MPI_File_write_at(fd, off, data, cnt, dtype, status));
    819:   if (!PetscBinaryBigEndian()) PetscCall(PetscByteSwap(data, pdtype, cnt));
    820:   PetscFunctionReturn(PETSC_SUCCESS);
    821: }

    823: PetscErrorCode MPIU_File_read_at(MPI_File fd, MPI_Offset off, void *data, PetscMPIInt cnt, MPI_Datatype dtype, MPI_Status *status)
    824: {
    825:   PetscDataType pdtype;

    827:   PetscFunctionBegin;
    828:   PetscCall(PetscMPIDataTypeToPetscDataType(dtype, &pdtype));
    829:   PetscCallMPI(MPI_File_read_at(fd, off, data, cnt, dtype, status));
    830:   if (!PetscBinaryBigEndian()) PetscCall(PetscByteSwap(data, pdtype, cnt));
    831:   PetscFunctionReturn(PETSC_SUCCESS);
    832: }

    834: PetscErrorCode MPIU_File_write_at_all(MPI_File fd, MPI_Offset off, void *data, PetscMPIInt cnt, MPI_Datatype dtype, MPI_Status *status)
    835: {
    836:   PetscDataType pdtype;

    838:   PetscFunctionBegin;
    839:   PetscCall(PetscMPIDataTypeToPetscDataType(dtype, &pdtype));
    840:   if (!PetscBinaryBigEndian()) PetscCall(PetscByteSwap(data, pdtype, cnt));
    841:   PetscCallMPI(MPI_File_write_at_all(fd, off, data, cnt, dtype, status));
    842:   if (!PetscBinaryBigEndian()) PetscCall(PetscByteSwap(data, pdtype, cnt));
    843:   PetscFunctionReturn(PETSC_SUCCESS);
    844: }

    846: PetscErrorCode MPIU_File_read_at_all(MPI_File fd, MPI_Offset off, void *data, PetscMPIInt cnt, MPI_Datatype dtype, MPI_Status *status)
    847: {
    848:   PetscDataType pdtype;

    850:   PetscFunctionBegin;
    851:   PetscCall(PetscMPIDataTypeToPetscDataType(dtype, &pdtype));
    852:   PetscCallMPI(MPI_File_read_at_all(fd, off, data, cnt, dtype, status));
    853:   if (!PetscBinaryBigEndian()) PetscCall(PetscByteSwap(data, pdtype, cnt));
    854:   PetscFunctionReturn(PETSC_SUCCESS);
    855: }

    857: #endif