/* * Copyright (C) 1997 NCSA * All rights reserved. * * Programmer: Robb Matzke * Wednesday, October 22, 1997 * * Purpose: This is the Posix section-2 I/O subclass of H5Flow. * * Notes: This driver keeps track of its own file position in order to * minimize the number of calls to lseek(). We assume that * opening a file sets the current file position to the beginning * and that read() and write() modify the file position as * expected when they return successfully (unsuccessful return * leaves the file position undefined). */ #include #include #include #include #define PABLO_MASK H5F_sec2 static hbool_t interface_initialize_g = FALSE; static H5F_low_t *H5F_sec2_open (const char *name, uintn flags); static herr_t H5F_sec2_close (H5F_low_t *lf); static herr_t H5F_sec2_read (H5F_low_t *lf, haddr_t addr, size_t size, uint8 *buf); static herr_t H5F_sec2_write (H5F_low_t *lf, haddr_t addr, size_t size, const uint8 *buf); static herr_t H5F_sec2_flush (H5F_low_t *lf); static size_t H5F_sec2_size (H5F_low_t *lf); const H5F_low_class_t H5F_LOW_SEC2[1] = {{ H5F_sec2_open, /* open method */ H5F_sec2_close, /* close method */ H5F_sec2_read, /* read method */ H5F_sec2_write, /* write method */ H5F_sec2_flush, /* flush method */ H5F_sec2_size, /* file size method */ }}; /*------------------------------------------------------------------------- * Function: H5F_sec2_open * * Purpose: Opens a file with name NAME. The FLAGS are a bit field with * the possible values defined in H5F_low_open(). * * Errors: * IO CANTOPENFILE Open failed. * * Return: Success: Low-level file pointer * * Failure: NULL * * Programmer: Robb Matzke * Wednesday, October 22, 1997 * * Modifications: * *------------------------------------------------------------------------- */ static H5F_low_t * H5F_sec2_open (const char *name, uintn flags) { uintn oflags; H5F_low_t *lf = NULL; int fd; FUNC_ENTER (H5F_sec2_open, NULL, NULL); oflags = (flags & H5F_ACC_WRITE) ? O_RDWR : O_RDONLY; oflags |= (flags & H5F_ACC_CREAT) ? O_CREAT : 0; oflags |= (flags & H5F_ACC_EXCL) ? O_EXCL : 0; oflags |= (flags & H5F_ACC_TRUNC) ? O_TRUNC : 0; if ((fd=open (name, oflags, 0666))<0) { HRETURN_ERROR (H5E_IO, H5E_CANTOPENFILE, NULL);/*open failed*/ } lf = H5MM_xcalloc (1, sizeof(H5F_low_t)); lf->u.sec2.fd = fd; lf->u.sec2.op = H5F_OP_SEEK; lf->u.sec2.cur = 0; FUNC_LEAVE (lf); } /*------------------------------------------------------------------------- * Function: H5F_sec2_close * * Purpose: Closes a file. * * Errors: * IO CLOSEERROR Close failed. * * Return: Success: SUCCEED * * Failure: FAIL * * Programmer: Robb Matzke * Wednesday, October 22, 1997 * * Modifications: * *------------------------------------------------------------------------- */ static herr_t H5F_sec2_close (H5F_low_t *lf) { FUNC_ENTER (H5F_sec2_close, NULL, FAIL); if (close (lf->u.sec2.fd)<0) { HRETURN_ERROR (H5E_IO, H5E_CLOSEERROR, FAIL); /*close failed*/ } lf->u.sec2.fd = -1; FUNC_LEAVE (SUCCEED); } /*------------------------------------------------------------------------- * Function: H5F_sec2_read * * Purpose: Reads SIZE bytes beginning at address ADDR in file LF and * places them in buffer BUF. Reading past the end of the * file returns zeros instead of failing. * * Errors: * IO READERROR Read failed. * IO SEEKERROR Lseek failed. * * Return: Success: SUCCEED * * Failure: FAIL * * Programmer: Robb Matzke * Wednesday, October 22, 1997 * * Modifications: * *------------------------------------------------------------------------- */ static herr_t H5F_sec2_read (H5F_low_t *lf, haddr_t addr, size_t size, uint8 *buf) { ssize_t n; FUNC_ENTER (H5F_sec2_read, NULL, FAIL); /* * Optimize seeking. If that optimization is disabled then alwasy call * lseek(). */ if (!H5F_OPT_SEEK || lf->u.sec2.op==H5F_OP_UNKNOWN || lf->u.sec2.cur!=addr) { if (lseek (lf->u.sec2.fd, addr, SEEK_SET)<0) { HRETURN_ERROR (H5E_IO, H5E_SEEKERROR, FAIL); /*lseek failed*/ } lf->u.sec2.cur = addr; } /* * Read the data. If a read error occurs then set the last file operation * to UNKNOWN because the file position isn't guaranteed by Posix. */ if ((n=read (lf->u.sec2.fd, buf, size))<0) { lf->u.sec2.op = H5F_OP_UNKNOWN; HRETURN_ERROR (H5E_IO, H5E_READERROR, FAIL); /*read failed*/ } else if (nu.sec2.op = H5F_OP_READ; lf->u.sec2.cur = addr + n; FUNC_LEAVE (SUCCEED); } /*------------------------------------------------------------------------- * Function: H5F_sec2_write * * Purpose: Writes SIZE bytes from the beginning of BUF into file LF at * file address ADDR. * * Errors: * IO SEEKERROR Lseek failed. * IO WRITEERROR Write failed. * * Return: Success: SUCCEED * * Failure: FAIL * * Programmer: Robb Matzke * Wednesday, October 22, 1997 * * Modifications: * *------------------------------------------------------------------------- */ static herr_t H5F_sec2_write (H5F_low_t *lf, haddr_t addr, size_t size, const uint8 *buf) { FUNC_ENTER (H5F_sec2_write, NULL, FAIL); /* * Optimize seeking. If that optimization is disabled then always call * lseek(). */ if (!H5F_OPT_SEEK || lf->u.sec2.op==H5F_OP_UNKNOWN || lf->u.sec2.cur!=addr) { if (lseek (lf->u.sec2.fd, addr, SEEK_SET)<0) { HRETURN_ERROR (H5E_IO, H5E_SEEKERROR, FAIL); /*lseek failed*/ } lf->u.sec2.cur = addr; } /* * Read the data from the file. If the write failed then set the * operation back to UNKNOWN since Posix doesn't gurantee its value. */ if (size != write (lf->u.sec2.fd, buf, size)) { lf->u.sec2.op = H5F_OP_UNKNOWN; HRETURN_ERROR (H5E_IO, H5E_WRITEERROR, FAIL); /*write failed*/ } /* * Update the file position. */ lf->u.sec2.op = H5F_OP_WRITE; lf->u.sec2.cur = addr + size; FUNC_LEAVE (SUCCEED); } /*------------------------------------------------------------------------- * Function: H5F_sec2_flush * * Purpose: Makes sure that all data is on disk. * * Errors: * * Return: Success: SUCCEED * * Failure: FAIL * * Programmer: Robb Matzke * Wednesday, October 22, 1997 * * Modifications: * *------------------------------------------------------------------------- */ static herr_t H5F_sec2_flush (H5F_low_t *lf) { FUNC_ENTER (H5F_sec2_flush, NULL, FAIL); /* Not necessary with this driver */ FUNC_LEAVE (SUCCEED); } /*------------------------------------------------------------------------- * Function: H5F_sec2_size * * Purpose: Returns the current size of the file in bytes. * * Bugs: There is no way to determine if this function failed. * * Errors: * IO SEEKERROR Lseek failed. * * Return: Success: Size of file in bytes * * Failure: 0 * * Programmer: Robb Matzke * Wednesday, October 22, 1997 * * Modifications: * *------------------------------------------------------------------------- */ static size_t H5F_sec2_size (H5F_low_t *lf) { off_t size; FUNC_ENTER (H5F_sec2_size, NULL, 0); if ((size=lseek (lf->u.sec2.fd, 0, SEEK_END))<0) { lf->u.sec2.op = H5F_OP_UNKNOWN; HRETURN_ERROR (H5E_IO, H5E_SEEKERROR, 0); /*lseek failed*/ } lf->u.sec2.op = H5F_OP_SEEK; lf->u.sec2.cur = size; FUNC_LEAVE (size); }