diff options
Diffstat (limited to 'src/H5Tprecis.c')
| -rw-r--r-- | src/H5Tprecis.c | 266 |
1 files changed, 266 insertions, 0 deletions
diff --git a/src/H5Tprecis.c b/src/H5Tprecis.c new file mode 100644 index 0000000..60a82aa --- /dev/null +++ b/src/H5Tprecis.c @@ -0,0 +1,266 @@ +/* * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * + * Copyright by the Board of Trustees of the University of Illinois. * + * All rights reserved. * + * * + * This file is part of HDF5. The full HDF5 copyright notice, including * + * terms governing use, modification, and redistribution, is contained in * + * the files COPYING and Copyright.html. COPYING can be found at the root * + * of the source code distribution tree; Copyright.html can be found at the * + * root level of an installed copy of the electronic HDF5 document set and * + * is linked from the top-level documents page. It can also be found at * + * http://hdf.ncsa.uiuc.edu/HDF5/doc/Copyright.html. If you do not have * + * access to either file, you may request a copy from hdfhelp@ncsa.uiuc.edu. * + * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * */ + +/* + * Module Info: This module contains the functionality for setting & querying + * the datatype precision for the H5T interface. + */ + +#define H5T_PACKAGE /*suppress error about including H5Tpkg */ + +#include "H5private.h" /*generic functions */ +#include "H5Eprivate.h" /*error handling */ +#include "H5Iprivate.h" /*ID functions */ +#include "H5Tpkg.h" /*data-type functions */ + +#define PABLO_MASK H5Tprecis_mask + +/* Interface initialization */ +static int interface_initialize_g = 0; +#define INTERFACE_INIT H5T_init_precis_interface +static herr_t H5T_init_precis_interface(void); + +/* Static local functions */ +static herr_t H5T_set_precision(H5T_t *dt, size_t prec); + + +/*-------------------------------------------------------------------------- +NAME + H5T_init_precis_interface -- Initialize interface-specific information +USAGE + herr_t H5T_init_precis_interface() + +RETURNS + Non-negative on success/Negative on failure +DESCRIPTION + Initializes any interface-specific data or routines. (Just calls + H5T_init_iterface currently). + +--------------------------------------------------------------------------*/ +static herr_t +H5T_init_precis_interface(void) +{ + FUNC_ENTER_NOINIT(H5T_init_precis_interface); + + FUNC_LEAVE_NOAPI(H5T_init_interface()); +} /* H5T_init_precis_interface() */ + + +/*------------------------------------------------------------------------- + * Function: H5Tget_precision + * + * Purpose: Gets the precision of a data type. The precision is + * the number of significant bits which, unless padding is + * present, is 8 times larger than the value returned by + * H5Tget_size(). + * + * Return: Success: Number of significant bits + * + * Failure: 0 (all atomic types have at least one + * significant bit) + * + * Programmer: Robb Matzke + * Wednesday, January 7, 1998 + * + * Modifications: + * Robb Matzke, 22 Dec 1998 + * Also works for derived data types. + * + *------------------------------------------------------------------------- + */ +size_t +H5Tget_precision(hid_t type_id) +{ + H5T_t *dt = NULL; + size_t ret_value; + + FUNC_ENTER_API(H5Tget_precision, 0); + H5TRACE1("z","i",type_id); + + /* Check args */ + if (NULL == (dt = H5I_object_verify(type_id,H5I_DATATYPE))) + HGOTO_ERROR(H5E_ARGS, H5E_BADTYPE, 0, "not a data type"); + if (dt->parent) + dt = dt->parent; /*defer to parent*/ + if (H5T_COMPOUND==dt->type || H5T_OPAQUE==dt->type || H5T_ARRAY==dt->type) + HGOTO_ERROR(H5E_DATATYPE, H5E_CANTINIT, 0, "operation not defined for specified data type"); + + /* Precision */ + assert(H5T_is_atomic(dt)); + ret_value = dt->u.atomic.prec; + +done: + FUNC_LEAVE_API(ret_value); +} + + +/*------------------------------------------------------------------------- + * Function: H5Tset_precision + * + * Purpose: Sets the precision of a data type. The precision is + * the number of significant bits which, unless padding is + * present, is 8 times larger than the value returned by + * H5Tget_size(). + * + * If the precision is increased then the offset is decreased + * and then the size is increased to insure that significant + * bits do not "hang over" the edge of the data type. + * + * The precision property of strings is read-only. + * + * When decreasing the precision of a floating point type, set + * the locations and sizes of the sign, mantissa, and exponent + * fields first. + * + * Return: Non-negative on success/Negative on failure + * + * Programmer: Robb Matzke + * Wednesday, January 7, 1998 + * + * Modifications: + * Robb Matzke, 22 Dec 1998 + * Moved real work to a private function. + * + *------------------------------------------------------------------------- + */ +herr_t +H5Tset_precision(hid_t type_id, size_t prec) +{ + H5T_t *dt = NULL; + herr_t ret_value=SUCCEED; /* Return value */ + + FUNC_ENTER_API(H5Tset_precision, FAIL); + H5TRACE2("e","iz",type_id,prec); + + /* Check args */ + if (NULL == (dt = H5I_object_verify(type_id,H5I_DATATYPE))) + HGOTO_ERROR(H5E_ARGS, H5E_BADTYPE, FAIL, "not a data type"); + if (H5T_STATE_TRANSIENT!=dt->state) + HGOTO_ERROR(H5E_ARGS, H5E_CANTINIT, FAIL, "data type is read-only"); + if (prec <= 0) + HGOTO_ERROR(H5E_ARGS, H5E_BADVALUE, FAIL, "precision must be positive"); + if (H5T_ENUM==dt->type && dt->u.enumer.nmembs>0) + HGOTO_ERROR(H5E_DATATYPE, H5E_CANTINIT, FAIL, "operation not allowed after members are defined"); + + /* Do the work */ + if (H5T_set_precision(dt, prec)<0) + HGOTO_ERROR(H5E_DATATYPE, H5E_CANTINIT, FAIL, "unable to set precision"); + +done: + FUNC_LEAVE_API(ret_value); +} + + +/*------------------------------------------------------------------------- + * Function: H5T_set_precision + * + * Purpose: Sets the precision of a data type. The precision is + * the number of significant bits which, unless padding is + * present, is 8 times larger than the value returned by + * H5Tget_size(). + * + * If the precision is increased then the offset is decreased + * and then the size is increased to insure that significant + * bits do not "hang over" the edge of the data type. + * + * The precision property of strings is read-only. + * + * When decreasing the precision of a floating point type, set + * the locations and sizes of the sign, mantissa, and exponent + * fields first. + * + * Return: Non-negative on success/Negative on failure + * + * Programmer: Robb Matzke + * Wednesday, January 7, 1998 + * + * Modifications: + * Robb Matzke, 22 Dec 1998 + * Also works for derived data types. + * + *------------------------------------------------------------------------- + */ +static herr_t +H5T_set_precision(H5T_t *dt, size_t prec) +{ + size_t offset, size; + herr_t ret_value=SUCCEED; /* Return value */ + + FUNC_ENTER_NOAPI(H5T_set_precision, FAIL); + + /* Check args */ + assert(dt); + assert(prec>0); + assert(H5T_ENUM!=dt->type || 0==dt->u.enumer.nmembs); + + if (dt->parent) { + if (H5T_set_precision(dt->parent, prec)<0) + HGOTO_ERROR(H5E_DATATYPE, H5E_CANTINIT, FAIL, "unable to set precision for base type"); + dt->size = dt->parent->size; + } else { + if (H5T_COMPOUND==dt->type || H5T_OPAQUE==dt->type || H5T_ARRAY==dt->type) { + HGOTO_ERROR(H5E_DATATYPE, H5E_CANTINIT, FAIL, "operation not defined for specified data type"); + } else if (H5T_ENUM==dt->type) { + /*nothing*/ + } else if (H5T_is_atomic(dt)) { + /* Adjust the offset and size */ + offset = dt->u.atomic.offset; + size = dt->size; + if (prec > 8*size) + offset = 0; + else if (offset+prec > 8 * size) offset = 8 * size - prec; + if (prec > 8*size) + size = (prec+7) / 8; + + /* Check that things are still kosher */ + switch (dt->type) { + case H5T_INTEGER: + case H5T_TIME: + case H5T_BITFIELD: + /* nothing to check */ + break; + + case H5T_STRING: + HGOTO_ERROR(H5E_ARGS, H5E_UNSUPPORTED, FAIL, "precision for this type is read-only"); + + case H5T_FLOAT: + /* + * The sign, mantissa, and exponent fields should be adjusted + * first when decreasing the precision of a floating point + * type. + */ + if (dt->u.atomic.u.f.sign >= prec || + dt->u.atomic.u.f.epos + dt->u.atomic.u.f.esize > prec || + dt->u.atomic.u.f.mpos + dt->u.atomic.u.f.msize > prec) { + HGOTO_ERROR(H5E_ARGS, H5E_BADVALUE, FAIL, "adjust sign, mantissa, and exponent fields first"); + } + break; + + default: + assert("not implemented yet" && 0); + } + + /* Commit */ + dt->size = size; + if (H5T_is_atomic(dt)) { + dt->u.atomic.offset = offset; + dt->u.atomic.prec = prec; + } + } + } + +done: + FUNC_LEAVE_NOAPI(ret_value); +} + |