/* * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * 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. * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * */ #define H5Z_PACKAGE /*suppress error about including H5Zpkg */ #include "H5private.h" /* Generic Functions */ #include "H5Eprivate.h" /* Error handling */ #include "H5MMprivate.h" /* Memory management */ #include "H5Ppublic.h" /* Property lists */ #include "H5Oprivate.h" /* Object headers */ #include "H5Tpublic.h" /* Datatype functions */ #include "H5Zpkg.h" /* Data filters */ #ifdef H5_HAVE_FILTER_SCALEOFFSET /* Struct of parameters needed for compressing/decompressing one atomic datatype */ typedef struct { size_t size; /* datatype size */ uint32_t minbits; /* minimum bits to compress one value of such datatype */ unsigned mem_order; /* current memory endianness order */ } parms_atomic; enum H5Z_scaleoffset_type {t_uchar=1, t_ushort, t_uint, t_ulong, t_ulong_long, t_schar, t_short, t_int, t_long, t_long_long}; /* Local function prototypes */ static herr_t H5Z_can_apply_scaleoffset(hid_t dcpl_id, hid_t type_id, hid_t space_id); static enum H5Z_scaleoffset_type H5Z_scaleoffset_get_type(unsigned dtype_size, unsigned dtype_sign); static herr_t H5Z_scaleoffset_set_parms_fillval(hid_t dcpl_id, hid_t type_id, enum H5Z_scaleoffset_type type, unsigned cd_values[], int need_convert); static herr_t H5Z_set_local_scaleoffset(hid_t dcpl_id, hid_t type_id, hid_t space_id); static size_t H5Z_filter_scaleoffset(unsigned flags, size_t cd_nelmts, const unsigned cd_values[], size_t nbytes, size_t *buf_size, void **buf); static void H5Z_scaleoffset_convert(void *buf, unsigned d_nelmts, unsigned dtype_size); static unsigned H5Z_scaleoffset_log2(unsigned long_long num); static void H5Z_scaleoffset_precompress(void *data, unsigned d_nelmts, enum H5Z_scaleoffset_type type, unsigned filavail, void *filval_buf, uint32_t *minbits, unsigned long_long *minval); static void H5Z_scaleoffset_postdecompress(void *data, unsigned d_nelmts, enum H5Z_scaleoffset_type type, unsigned filavail, void *filval_buf, uint32_t minbits, unsigned long_long minval); static void H5Z_scaleoffset_next_byte(size_t *j, int *buf_len); static void H5Z_scaleoffset_decompress_one_byte(unsigned char *data, size_t data_offset, int k, int begin_i, unsigned char *buffer, size_t *j, int *buf_len, parms_atomic p, int dtype_len); static void H5Z_scaleoffset_compress_one_byte(unsigned char *data, size_t data_offset, int k, int begin_i, unsigned char *buffer, size_t *j, int *buf_len, parms_atomic p, int dtype_len); static void H5Z_scaleoffset_decompress_one_atomic(unsigned char *data, size_t data_offset, unsigned char *buffer, size_t *j, int *buf_len, parms_atomic p); static void H5Z_scaleoffset_compress_one_atomic(unsigned char *data, size_t data_offset, unsigned char *buffer, size_t *j, int *buf_len, parms_atomic p); static void H5Z_scaleoffset_decompress(unsigned char *data, unsigned d_nelmts, unsigned char *buffer, parms_atomic p); static void H5Z_scaleoffset_compress(unsigned char *data, unsigned d_nelmts, unsigned char *buffer, size_t buffer_size, parms_atomic p); /* This message derives from H5Z */ H5Z_class_t H5Z_SCALEOFFSET[1] = {{ H5Z_CLASS_T_VERS, /* H5Z_class_t version */ H5Z_FILTER_SCALEOFFSET, /* Filter id number */ 1, /* Assume encoder present: check before registering */ 1, /* decoder_present flag (set to true) */ "scaleoffset", /* Filter name for debugging */ H5Z_can_apply_scaleoffset, /* The "can apply" callback */ H5Z_set_local_scaleoffset, /* The "set local" callback */ H5Z_filter_scaleoffset, /* The actual filter function */ }}; /* Local macros */ #define H5Z_SCALEOFFSET_USER_NPARMS 1 /* Number of parameters that users can set */ #define H5Z_SCALEOFFSET_TOTAL_NPARMS 20 /* Total number of parameters for filter */ #define H5Z_SCALEOFFSET_PARM_MINBITS 0 /* "User" parameter for minimum number of bits */ #define H5Z_SCALEOFFSET_PARM_NELMTS 1 /* "Local" parameter for number of elements in the chunk */ #define H5Z_SCALEOFFSET_PARM_CLASS 2 /* "Local" parameter for datatype class */ #define H5Z_SCALEOFFSET_PARM_SIZE 3 /* "Local" parameter for datatype size */ #define H5Z_SCALEOFFSET_PARM_SIGN 4 /* "Local" parameter for integer datatype sign */ #define H5Z_SCALEOFFSET_PARM_ORDER 5 /* "Local" parameter for datatype byte order */ #define H5Z_SCALEOFFSET_PARM_FILAVAIL 6 /* "Local" parameter for dataset fill value existence */ #define H5Z_SCALEOFFSET_PARM_FILVAL 7 /* "Local" parameter for start location to store dataset fill value */ #define H5Z_SCALEOFFSET_CLS_INTEGER 0 /* Integer (datatype class) */ #define H5Z_SCALEOFFSET_CLS_FLOAT 1 /* Floatig-point (datatype class) */ #define H5Z_SCALEOFFSET_SGN_NONE 0 /* Unsigned integer type */ #define H5Z_SCALEOFFSET_SGN_2 1 /* Two's complement signed integer type */ #define H5Z_SCALEOFFSET_ORDER_LE 0 /* Little endian (datatype byte order) */ #define H5Z_SCALEOFFSET_ORDER_BE 1 /* Big endian (datatype byte order) */ #define H5Z_SCALEOFFSET_FILL_UNDEFINED 0 /* Fill value is not defined */ #define H5Z_SCALEOFFSET_FILL_DEFINED 1 /* Fill value is defined */ /*------------------------------------------------------------------------- * Function: H5Z_can_apply_scaleoffset * * Purpose: Check the parameters for scaleoffset compression for * validity and whether they fit a particular dataset. * * Return: Success: Non-negative * Failure: Negative * * Programmer: Xiaowen Wu * Friday, February 4, 2005 * * Modifications: * *------------------------------------------------------------------------- */ static herr_t H5Z_can_apply_scaleoffset(hid_t UNUSED dcpl_id, hid_t type_id, hid_t UNUSED space_id) { H5T_class_t dtype_class; /* Datatype's class */ unsigned dtype_size; /* Datatype's size (in bytes) */ H5T_order_t dtype_order; /* Datatype's endianness order */ herr_t ret_value=TRUE; /* Return value */ FUNC_ENTER_NOAPI(H5Z_can_apply_scaleoffset, FAIL) /* Get datatype's class, for checking the "datatype class" */ if((dtype_class = H5Tget_class(type_id)) == H5T_NO_CLASS ) HGOTO_ERROR(H5E_PLINE, H5E_BADTYPE, FAIL, "bad datatype class") /* Get datatype's size, for checking the "datatype size" */ if((dtype_size = H5Tget_size(type_id)) == 0) HGOTO_ERROR(H5E_PLINE, H5E_BADTYPE, FAIL, "bad datatype size") if(dtype_class == H5T_INTEGER || dtype_class == H5T_FLOAT) { /* Get datatype's endianness order */ if((dtype_order = H5Tget_order(type_id)) == H5T_ORDER_ERROR) HGOTO_ERROR(H5E_PLINE, H5E_BADTYPE, FAIL, "can't retrieve datatype endianness order") /* Range check datatype's endianness order */ if(dtype_order != H5T_ORDER_LE && dtype_order != H5T_ORDER_BE) HGOTO_ERROR(H5E_PLINE, H5E_BADTYPE, FAIL, "bad datatype endianness order") } else HGOTO_ERROR(H5E_PLINE, H5E_BADTYPE, FAIL, "datatype class not supported by scaleoffset") done: FUNC_LEAVE_NOAPI(ret_value) } /* end H5Z_can_apply_scaleoffset() */ /*------------------------------------------------------------------------- * Function: H5Z_scaleoffset_get_type * * Purpose: Get the specific integer type based on datatype size and sign * * Return: Success: id number of integer type * Failure: 0 * * Programmer: Xiaowen Wu * Saturday, February 26, 2005 * * Modifications: * *------------------------------------------------------------------------- */ static enum H5Z_scaleoffset_type H5Z_scaleoffset_get_type(unsigned dtype_size, unsigned dtype_sign) { enum H5Z_scaleoffset_type type; /* integer type */ unsigned ret_value; /* return value */ FUNC_ENTER_NOAPI(H5Z_scaleoffset_get_type, 0) if(dtype_sign==H5Z_SCALEOFFSET_SGN_NONE) { /* unsigned integer */ if(dtype_size == sizeof(unsigned char)) type = t_uchar; else if(dtype_size == sizeof(unsigned short)) type = t_ushort; else if(dtype_size == sizeof(unsigned int)) type = t_uint; else if(dtype_size == sizeof(unsigned long)) type = t_ulong; else if(dtype_size == sizeof(unsigned long_long)) type = t_ulong_long; else HGOTO_ERROR(H5E_PLINE, H5E_BADTYPE, 0, "integer size not matched") } if(dtype_sign==H5Z_SCALEOFFSET_SGN_2) { /* signed integer */ if(dtype_size == sizeof(signed char)) type = t_schar; else if(dtype_size == sizeof(short)) type = t_short; else if(dtype_size == sizeof(int)) type = t_int; else if(dtype_size == sizeof(long)) type = t_long; else if(dtype_size == sizeof(long_long)) type = t_long_long; else HGOTO_ERROR(H5E_PLINE, H5E_BADTYPE, 0, "integer size not matched") } done: ret_value = type; FUNC_LEAVE_NOAPI(ret_value) } /*------------------------------------------------------------------------- * Function: H5Z_scaleoffset_set_parms_fillval * * Purpose: Get the fill value of the dataset and store in cd_values[] * * Return: Success: Non-negative * Failure: Negative * * Programmer: Xiaowen Wu * Monday, March 7, 2005 * * Modifications: * *------------------------------------------------------------------------- */ static herr_t H5Z_scaleoffset_set_parms_fillval(hid_t dcpl_id, hid_t type_id, enum H5Z_scaleoffset_type type, unsigned cd_values[], int need_convert) { unsigned i; /* index */ herr_t ret_value=SUCCEED; /* Return value */ FUNC_ENTER_NOAPI(H5Z_scaleoffset_set_parms_fillval, FAIL) if(type == t_uchar) { unsigned char fill_val; /* Get dataset fill value */ if(H5Pget_fill_value(dcpl_id, type_id, &fill_val)<0) HGOTO_ERROR(H5E_PLINE, H5E_CANTGET, FAIL, "unable to get fill value") /* Store the fill value as the last entry in cd_values[] * Store byte by byte from least significant byte to most significant byte * Plenty of space left for the fill value (from index 7 to 19) */ for(i = 0; i < sizeof(unsigned char); i++) ((unsigned char *)&cd_values[H5Z_SCALEOFFSET_PARM_FILVAL])[i] = (fill_val & ((unsigned char)0xff << i*8)) >> i*8; } else if(type == t_ushort) { unsigned short fill_val; /* Get dataset fill value */ if(H5Pget_fill_value(dcpl_id, type_id, &fill_val)<0) HGOTO_ERROR(H5E_PLINE, H5E_CANTGET, FAIL, "unable to get fill value") if(need_convert) H5Z_scaleoffset_convert(&fill_val, 1, sizeof(unsigned short)); /* Store the fill value as the last entry in cd_values[] * Store byte by byte from least significant byte to most significant byte * Plenty of space left for the fill value (from index 7 to 19) */ for(i = 0; i < sizeof(unsigned short); i++) ((unsigned char *)&cd_values[H5Z_SCALEOFFSET_PARM_FILVAL])[i] = (fill_val & ((unsigned short)0xff << i*8)) >> i*8; } else if(type == t_uint) { unsigned int fill_val; /* Get dataset fill value */ if(H5Pget_fill_value(dcpl_id, type_id, &fill_val)<0) HGOTO_ERROR(H5E_PLINE, H5E_CANTGET, FAIL, "unable to get fill value") if(need_convert) H5Z_scaleoffset_convert(&fill_val, 1, sizeof(unsigned int)); /* Store the fill value as the last entry in cd_values[] * Store byte by byte from least significant byte to most significant byte * Plenty of space left for the fill value (from index 7 to 19) */ for(i = 0; i < sizeof(unsigned int); i++) ((unsigned char *)&cd_values[H5Z_SCALEOFFSET_PARM_FILVAL])[i] = (fill_val & ((unsigned int)0xff << i*8)) >> i*8; } else if(type == t_ulong) { unsigned long fill_val; /* Get dataset fill value */ if(H5Pget_fill_value(dcpl_id, type_id, &fill_val)<0) HGOTO_ERROR(H5E_PLINE, H5E_CANTGET, FAIL, "unable to get fill value") if(need_convert) H5Z_scaleoffset_convert(&fill_val, 1, sizeof(unsigned long)); /* Store the fill value as the last entry in cd_values[] * Store byte by byte from least significant byte to most significant byte * Plenty of space left for the fill value (from index 7 to 19) */ for(i = 0; i < sizeof(unsigned long); i++) ((unsigned char *)&cd_values[H5Z_SCALEOFFSET_PARM_FILVAL])[i] = (fill_val & ((unsigned long)0xff << i*8)) >> i*8; } else if(type == t_ulong_long) { unsigned long_long fill_val; /* Get dataset fill value */ if(H5Pget_fill_value(dcpl_id, type_id, &fill_val)<0) HGOTO_ERROR(H5E_PLINE, H5E_CANTGET, FAIL, "unable to get fill value") if(need_convert) H5Z_scaleoffset_convert(&fill_val, 1, sizeof(unsigned long_long)); /* Store the fill value as the last entry in cd_values[] * Store byte by byte from least significant byte to most significant byte * Plenty of space left for the fill value (from index 7 to 19) */ for(i = 0; i < sizeof(unsigned long_long); i++) ((unsigned char *)&cd_values[H5Z_SCALEOFFSET_PARM_FILVAL])[i] = (fill_val & ((unsigned long_long)0xff << i*8)) >> i*8; } else if(type == t_schar) { signed char fill_val; /* Get dataset fill value */ if(H5Pget_fill_value(dcpl_id, type_id, &fill_val)<0) HGOTO_ERROR(H5E_PLINE, H5E_CANTGET, FAIL, "unable to get fill value") /* Store the fill value as the last entry in cd_values[] * Store byte by byte from least significant byte to most significant byte * Plenty of space left for the fill value (from index 7 to 19) */ for(i = 0; i < sizeof(signed char); i++) ((unsigned char *)&cd_values[H5Z_SCALEOFFSET_PARM_FILVAL])[i] = (fill_val & ((unsigned char)0xff << i*8)) >> i*8; } else if(type == t_short) { short fill_val; /* Get dataset fill value */ if(H5Pget_fill_value(dcpl_id, type_id, &fill_val)<0) HGOTO_ERROR(H5E_PLINE, H5E_CANTGET, FAIL, "unable to get fill value") if(need_convert) H5Z_scaleoffset_convert(&fill_val, 1, sizeof(short)); /* Store the fill value as the last entry in cd_values[] * Store byte by byte from least significant byte to most significant byte * Plenty of space left for the fill value (from index 7 to 19) */ for(i = 0; i < sizeof(short); i++) ((unsigned char *)&cd_values[H5Z_SCALEOFFSET_PARM_FILVAL])[i] = (fill_val & ((unsigned short)0xff << i*8)) >> i*8; } else if(type == t_int) { int fill_val; /* Get dataset fill value */ if(H5Pget_fill_value(dcpl_id, type_id, &fill_val)<0) HGOTO_ERROR(H5E_PLINE, H5E_CANTGET, FAIL, "unable to get fill value") if(need_convert) H5Z_scaleoffset_convert(&fill_val, 1, sizeof(int)); /* Store the fill value as the last entry in cd_values[] * Store byte by byte from least significant byte to most significant byte * Plenty of space left for the fill value (from index 7 to 19) */ for(i = 0; i < sizeof(int); i++) ((unsigned char *)&cd_values[H5Z_SCALEOFFSET_PARM_FILVAL])[i] = (fill_val & ((unsigned int)0xff << i*8)) >> i*8; } else if(type == t_long) { long fill_val; /* Get dataset fill value */ if(H5Pget_fill_value(dcpl_id, type_id, &fill_val)<0) HGOTO_ERROR(H5E_PLINE, H5E_CANTGET, FAIL, "unable to get fill value") if(need_convert) H5Z_scaleoffset_convert(&fill_val, 1, sizeof(long)); /* Store the fill value as the last entry in cd_values[] * Store byte by byte from least significant byte to most significant byte * Plenty of space left for the fill value (from index 7 to 19) */ for(i = 0; i < sizeof(long); i++) ((unsigned char *)&cd_values[H5Z_SCALEOFFSET_PARM_FILVAL])[i] = (fill_val & ((unsigned long)0xff << i*8)) >> i*8; } else if(type == t_long_long) { long_long fill_val; /* Get dataset fill value */ if(H5Pget_fill_value(dcpl_id, type_id, &fill_val)<0) HGOTO_ERROR(H5E_PLINE, H5E_CANTGET, FAIL, "unable to get fill value") if(need_convert) H5Z_scaleoffset_convert(&fill_val, 1, sizeof(long_long)); /* Store the fill value as the last entry in cd_values[] * Store byte by byte from least significant byte to most significant byte * Plenty of space left for the fill value (from index 7 to 19) */ for(i = 0; i < sizeof(long_long); i++) ((unsigned char *)&cd_values[H5Z_SCALEOFFSET_PARM_FILVAL])[i] = (fill_val & ((unsigned long_long)0xff << i*8)) >> i*8; } done: FUNC_LEAVE_NOAPI(ret_value) } /* end H5Z_scaleoffset_set_parms_fillval() */ /*------------------------------------------------------------------------- * Function: H5Z_set_local_scaleoffset * * Purpose: Set the "local" dataset parameters for scaleoffset * compression. * * Return: Success: Non-negative * Failure: Negative * * Programmer: Xiaowen Wu * Friday, February 4, 2005 * * Modifications: * *------------------------------------------------------------------------- */ static herr_t H5Z_set_local_scaleoffset(hid_t dcpl_id, hid_t type_id, hid_t space_id) { unsigned flags; /* Filter flags */ size_t cd_nelmts=H5Z_SCALEOFFSET_USER_NPARMS; /* Number of filter parameters */ unsigned cd_values[H5Z_SCALEOFFSET_TOTAL_NPARMS]; /* Filter parameters */ hssize_t npoints; /* Number of points in the dataspace */ H5T_class_t dtype_class; /* Datatype's class */ H5T_order_t dtype_order; /* Datatype's endianness order */ H5T_order_t mem_order; /* Memory's endianness order */ int need_convert = FALSE; /* Flag indicating convertion of byte order */ size_t dtype_size; /* Datatype's size (in bytes) */ H5T_sign_t dtype_sign; /* Datatype's sign */ enum H5Z_scaleoffset_type type; /* integer type */ H5D_fill_value_t status; /* Status of fill value in property list */ herr_t ret_value=SUCCEED; /* Return value */ FUNC_ENTER_NOAPI(H5Z_set_local_scaleoffset, FAIL) /* Get the filter's current parameters */ #ifdef H5_WANT_H5_V1_6_COMPAT if(H5Pget_filter_by_id(dcpl_id,H5Z_FILTER_SCALEOFFSET,&flags,&cd_nelmts,cd_values,0,NULL)<0) #else if(H5Pget_filter_by_id(dcpl_id,H5Z_FILTER_SCALEOFFSET,&flags,&cd_nelmts,cd_values,0,NULL,NULL)<0) #endif HGOTO_ERROR(H5E_PLINE, H5E_CANTGET, FAIL, "can't get scaleoffset parameters") /* Get total number of elements in the chunk */ if ((npoints=H5Sget_simple_extent_npoints(space_id))<0) HGOTO_ERROR(H5E_PLINE, H5E_CANTGET, FAIL, "unable to get number of points in the dataspace") /* Set "local" parameter for this dataset's number of elements */ H5_ASSIGN_OVERFLOW(cd_values[H5Z_SCALEOFFSET_PARM_NELMTS],npoints,hssize_t,unsigned); /* Get datatype's class */ if((dtype_class=H5Tget_class(type_id))==H5T_NO_CLASS ) HGOTO_ERROR(H5E_PLINE, H5E_BADTYPE, FAIL, "bad datatype class") /* Set "local" parameter for datatype's class */ switch(dtype_class) { case H5T_INTEGER: cd_values[H5Z_SCALEOFFSET_PARM_CLASS] = H5Z_SCALEOFFSET_CLS_INTEGER; break; case H5T_FLOAT: cd_values[H5Z_SCALEOFFSET_PARM_CLASS] = H5Z_SCALEOFFSET_CLS_FLOAT; break; default: HGOTO_ERROR(H5E_PLINE, H5E_BADTYPE, FAIL, "datatype class not supported by scaleoffset") } /* end switch */ /* Get datatype's size */ if((dtype_size=H5Tget_size(type_id))==0) HGOTO_ERROR(H5E_PLINE, H5E_BADTYPE, FAIL, "bad datatype size") /* Set "local" parameter for datatype size */ cd_values[H5Z_SCALEOFFSET_PARM_SIZE] = dtype_size; if(dtype_class==H5T_INTEGER) { /* Get datatype's sign */ if((dtype_sign=H5Tget_sign(type_id))==H5T_SGN_ERROR) HGOTO_ERROR(H5E_PLINE, H5E_BADTYPE, FAIL, "bad datatype sign") /* Set "local" parameter for integer datatype sign */ switch(dtype_sign) { case H5T_SGN_NONE: cd_values[H5Z_SCALEOFFSET_PARM_SIGN] = H5Z_SCALEOFFSET_SGN_NONE; break; case H5T_SGN_2: cd_values[H5Z_SCALEOFFSET_PARM_SIGN] = H5Z_SCALEOFFSET_SGN_2; break; default: HGOTO_ERROR(H5E_PLINE, H5E_BADTYPE, FAIL, "bad integer sign") } /* end switch */ } /* Get datatype's endianness order */ if((dtype_order=H5Tget_order(type_id))==H5T_ORDER_ERROR) HGOTO_ERROR(H5E_PLINE, H5E_BADTYPE, FAIL, "bad datatype endianness order") /* Set "local" parameter for datatype endianness */ switch(dtype_order) { case H5T_ORDER_LE: /* Little-endian byte order */ cd_values[H5Z_SCALEOFFSET_PARM_ORDER] = H5Z_SCALEOFFSET_ORDER_LE; break; case H5T_ORDER_BE: /* Big-endian byte order */ cd_values[H5Z_SCALEOFFSET_PARM_ORDER] = H5Z_SCALEOFFSET_ORDER_BE; break; default: HGOTO_ERROR(H5E_PLINE, H5E_BADTYPE, FAIL, "bad datatype endianness order") } /* end switch */ /* Check whether fill value is defined for dataset */ if(H5Pfill_value_defined(dcpl_id, &status)<0) HGOTO_ERROR(H5E_PLINE, H5E_CANTGET, FAIL, "unable to determine if fill value is defined") /* Set local parameter for availability of fill value */ if(status == H5D_FILL_VALUE_UNDEFINED) cd_values[H5Z_SCALEOFFSET_PARM_FILAVAIL] = H5Z_SCALEOFFSET_FILL_UNDEFINED; else { cd_values[H5Z_SCALEOFFSET_PARM_FILAVAIL] = H5Z_SCALEOFFSET_FILL_DEFINED; /* Get memory's endianness order */ if((mem_order=H5Tget_order(H5T_NATIVE_INT))==H5T_ORDER_ERROR) HGOTO_ERROR(H5E_PLINE, H5E_BADTYPE, 0, "bad H5T_NATIVE_INT endianness order") /* Check if memory byte order matches dataset datatype byte order */ switch(mem_order) { case H5T_ORDER_LE: /* memory is little-endian byte order */ if(dtype_order == H5T_ORDER_BE) need_convert = TRUE; break; case H5T_ORDER_BE: /* memory is big-endian byte order */ if(dtype_order == H5T_ORDER_LE) need_convert = TRUE; break; default: HGOTO_ERROR(H5E_PLINE, H5E_BADTYPE, 0, "bad H5T_NATIVE_INT endianness order") } /* end switch */ if(dtype_class==H5T_INTEGER) { /* Before getting fill value, get its integer type */ if((type = H5Z_scaleoffset_get_type(cd_values[H5Z_SCALEOFFSET_PARM_SIZE], cd_values[H5Z_SCALEOFFSET_PARM_SIGN]))==0) HGOTO_ERROR(H5E_PLINE, H5E_BADTYPE, 0, "cannot use C integer datatype for cast") /* Get dataset fill value and store in cd_values[] */ if(H5Z_scaleoffset_set_parms_fillval(dcpl_id, type_id, type, cd_values, need_convert)<0) HGOTO_ERROR(H5E_PLINE, H5E_CANTSET, FAIL, "unable to set fill value") } } /* Modify the filter's parameters for this dataset */ if(H5Pmodify_filter(dcpl_id, H5Z_FILTER_SCALEOFFSET, flags, H5Z_SCALEOFFSET_TOTAL_NPARMS, cd_values)<0) HGOTO_ERROR(H5E_PLINE, H5E_CANTSET, FAIL, "can't set local scaleoffset parameters") done: FUNC_LEAVE_NOAPI(ret_value) } /* end H5Z_set_local_scaleoffset() */ /*------------------------------------------------------------------------- * Function: H5Z_filter_scaleoffset * * Purpose: Implement an I/O filter for storing packed integer * data using scale and offset method. * * Return: Success: Size of buffer filtered * Failure: 0 * * Programmer: Xiaowen Wu * Monday, February 7, 2005 * * Modifications: * *------------------------------------------------------------------------- */ static size_t H5Z_filter_scaleoffset (unsigned flags, size_t cd_nelmts, const unsigned cd_values[], size_t nbytes, size_t *buf_size, void **buf) { size_t ret_value = 0; /* return value */ size_t size_out = 0; /* size of output buffer */ unsigned d_nelmts = 0; /* number of data elements in the chunk */ enum H5Z_scaleoffset_type type; /* integer type */ H5T_order_t mem_order; /* memory's endianness order */ int need_convert = FALSE; /* flag indicating convertion of byte order */ uint32_t minbits = 0; /* minimum number of bits to store values */ unsigned long_long minval= 0; /* minimum value of input buffer */ unsigned char *outbuf = NULL; /* pointer to new output buffer */ unsigned buf_offset = 21; /* buffer offset because of parameters stored in file */ unsigned i; /* index */ parms_atomic p; /* paramters needed for compress/decompress functions */ FUNC_ENTER_NOAPI(H5Z_filter_scaleoffset, 0) /* check arguments */ if (cd_nelmts!=H5Z_SCALEOFFSET_TOTAL_NPARMS) HGOTO_ERROR(H5E_ARGS, H5E_BADVALUE, 0, "invalid scaleoffset number of paramters") /* do not process if datatype is floating-point, will change later */ if(cd_values[H5Z_SCALEOFFSET_PARM_CLASS]==H5Z_SCALEOFFSET_CLS_FLOAT) { ret_value = *buf_size; goto done; } /* get memory's endianness order */ if((mem_order=H5Tget_order(H5T_NATIVE_INT))==H5T_ORDER_ERROR) HGOTO_ERROR(H5E_PLINE, H5E_BADTYPE, 0, "bad H5T_NATIVE_INT endianness order") /* check if memory byte order matches dataset datatype byte order */ switch(mem_order) { case H5T_ORDER_LE: /* memory is little-endian byte order */ if(cd_values[H5Z_SCALEOFFSET_PARM_ORDER] == H5Z_SCALEOFFSET_ORDER_BE) need_convert = TRUE; break; case H5T_ORDER_BE: /* memory is big-endian byte order */ if(cd_values[H5Z_SCALEOFFSET_PARM_ORDER] == H5Z_SCALEOFFSET_ORDER_LE) need_convert = TRUE; break; default: HGOTO_ERROR(H5E_PLINE, H5E_BADTYPE, 0, "bad H5T_NATIVE_INT endianness order") } /* end switch */ /* check and assign value to minimum number of bits if set by user */ if(cd_values[H5Z_SCALEOFFSET_PARM_MINBITS]!=0) { if(cd_values[H5Z_SCALEOFFSET_PARM_MINBITS]>cd_values[H5Z_SCALEOFFSET_PARM_SIZE]*8) HGOTO_ERROR(H5E_ARGS, H5E_BADVALUE, 0, "minimum number of bits exceeds maximum") /* no need to process data */ if(cd_values[H5Z_SCALEOFFSET_PARM_MINBITS]==cd_values[H5Z_SCALEOFFSET_PARM_SIZE]*8) { ret_value = *buf_size; goto done; } minbits = cd_values[H5Z_SCALEOFFSET_PARM_MINBITS]; } /* copy a filter parameter to d_nelmts */ d_nelmts = cd_values[H5Z_SCALEOFFSET_PARM_NELMTS]; /* prepare paramters to pass to compress/decompress functions */ p.size = cd_values[H5Z_SCALEOFFSET_PARM_SIZE]; p.mem_order = mem_order; /* input; decompress */ if (flags & H5Z_FLAG_REVERSE) { /* retrieve values of minbits and minval from input compressed buffer * retrieve them corresponding to how they are stored during compression */ uint32_t minbits_mask = 0; unsigned long_long minval_mask = 0; unsigned minval_size = 0; minbits = 0; for(i = 0; i < 4; i++) { minbits_mask = ((unsigned char *)*buf)[i]; minbits_mask <<= i*8; minbits |= minbits_mask; } /* retrieval of minval takes into consideration situation where sizeof * unsigned long_long (datatype of minval) may change from compression * to decompression */ minval_size = sizeof(unsigned long_long) <= ((unsigned char *)*buf)[4] ? sizeof(unsigned long_long) : ((unsigned char *)*buf)[4]; minval = 0; for(i = 0; i < minval_size; i++) { minval_mask = ((unsigned char *)*buf)[5+i]; minval_mask <<= i*8; minval |= minval_mask; } assert(minbits <= p.size * 8); p.minbits = minbits; /* calculate size of output buffer after decompression */ size_out = d_nelmts * p.size; /* allocate memory space for decompressed buffer */ if(NULL==(outbuf = H5MM_malloc(size_out))) HGOTO_ERROR(H5E_RESOURCE, H5E_NOSPACE, 0, "memory allocation failed for scaleoffset decompression") /* special case: minbits equal to full precision */ if(minbits == p.size * 8) { HDmemcpy(outbuf, (unsigned char*)(*buf)+buf_offset, size_out); /* convert to dataset datatype endianness order if needed */ if(need_convert) H5Z_scaleoffset_convert(outbuf, d_nelmts, p.size); *buf = outbuf; outbuf = NULL; *buf_size = size_out; ret_value = size_out; goto done; } /* decompress the buffer if minbits not equal to zero */ if(minbits != 0) H5Z_scaleoffset_decompress(outbuf, d_nelmts, (unsigned char*)(*buf)+buf_offset, p); else { /* fill value is not defined and all data elements have the same value */ for(i = 0; i < size_out; i++) outbuf[i] = 0; } /* before postprocess, get integer type */ if((type = H5Z_scaleoffset_get_type(cd_values[H5Z_SCALEOFFSET_PARM_SIZE], cd_values[H5Z_SCALEOFFSET_PARM_SIGN]))==0) HGOTO_ERROR(H5E_PLINE, H5E_BADTYPE, 0, "cannot use C integer datatype for cast") /* postprocess after decompression */ H5Z_scaleoffset_postdecompress(outbuf, d_nelmts, type, cd_values[H5Z_SCALEOFFSET_PARM_FILAVAIL], &cd_values[H5Z_SCALEOFFSET_PARM_FILVAL], minbits, minval); /* after postprocess, convert to dataset datatype endianness order if needed */ if(need_convert) H5Z_scaleoffset_convert(outbuf, d_nelmts, p.size); } /* output; compress */ else { assert(nbytes == d_nelmts * p.size); /* before preprocess, convert to memory endianness order if needed */ if(need_convert) H5Z_scaleoffset_convert(*buf, d_nelmts, p.size); /* before preprocess, get integer type */ if((type = H5Z_scaleoffset_get_type(cd_values[H5Z_SCALEOFFSET_PARM_SIZE], cd_values[H5Z_SCALEOFFSET_PARM_SIGN]))==0) HGOTO_ERROR(H5E_PLINE, H5E_BADTYPE, 0, "cannot use C integer datatype for cast") /* preprocess before compression */ H5Z_scaleoffset_precompress(*buf, d_nelmts, type, cd_values[H5Z_SCALEOFFSET_PARM_FILAVAIL], &cd_values[H5Z_SCALEOFFSET_PARM_FILVAL], &minbits, &minval); assert(minbits <= p.size * 8); /* calculate buffer size after compression * minbits and minval are stored in the front of the compressed buffer */ p.minbits = minbits; size_out = buf_offset + nbytes * p.minbits / (p.size * 8) + 1; /* may be 1 larger */ /* allocate memory space for compressed buffer */ if(NULL==(outbuf = H5MM_malloc(size_out))) HGOTO_ERROR(H5E_RESOURCE, H5E_NOSPACE, 0, "memory allocation failed for scaleoffset compression") /* store minbits and minval in the front of output compressed buffer * store byte by byte from least significant byte to most significant byte * constant buffer size (21 bytes) is left for these two parameters * 4 bytes for minbits, 1 byte for size of minval, 16 bytes for minval */ for(i = 0; i < 4; i++) ((unsigned char *)outbuf)[i] = (minbits & ((uint32_t)0xff << i*8)) >> i*8; ((unsigned char *)outbuf)[4] = sizeof(unsigned long_long); for(i = 0; i < sizeof(unsigned long_long); i++) ((unsigned char *)outbuf)[5+i] = (minval & ((unsigned long_long)0xff << i*8)) >> i*8; /* special case: minbits equal to full precision */ if(minbits == p.size * 8) { HDmemcpy(outbuf+buf_offset, *buf, nbytes); *buf = outbuf; outbuf = NULL; *buf_size = buf_offset+nbytes; ret_value = *buf_size; goto done; } /* compress the buffer if minbits not equal to zero * minbits equal to zero only when fill value is not defined and * all data elements have the same value */ if(minbits != 0) H5Z_scaleoffset_compress(*buf, d_nelmts, outbuf+buf_offset, size_out-buf_offset, p); } /* free the input buffer */ H5MM_xfree(*buf); /* set return values */ *buf = outbuf; outbuf = NULL; *buf_size = size_out; ret_value = size_out; done: if(outbuf) H5MM_xfree(outbuf); FUNC_LEAVE_NOAPI(ret_value) } /* ============ Scaleoffset Algorithm =============================================== * assume one byte has 8 bit * assume padding bit is 0 * assume size of unsigned char is one byte * assume one data item of certain datatype is stored continously in bytes * atomic datatype is treated on byte basis */ /* change byte order of input buffer either from little-endian to big-endian * or from big-endian to little-endian 2/21/2005 */ static void H5Z_scaleoffset_convert(void *buf, unsigned d_nelmts, unsigned dtype_size) { unsigned i, j; unsigned char *buffer, temp; if(dtype_size == 1) return; buffer = buf; for(i = 0; i < d_nelmts * dtype_size; i += dtype_size) for(j = 0; j < dtype_size/2; j++) { /* swap pair of bytes */ temp = buffer[i+j]; buffer[i+j] = buffer[i+dtype_size-1-j]; buffer[i+dtype_size-1-j] = temp; } } /* return ceiling of floating-point log2 function * receive unsigned integer as argument 3/10/2005 */ static unsigned H5Z_scaleoffset_log2(unsigned long_long num) { unsigned v = 0; unsigned long_long lower_bound = 1; /* is power of 2, largest value <= num */ unsigned long_long val = num; while(val >>= 1) { v++; lower_bound <<= 1; } if(num == lower_bound) return v; else return v+1; } static void H5Z_scaleoffset_precompress(void *data, unsigned d_nelmts, enum H5Z_scaleoffset_type type, unsigned filavail, void *filval_buf, uint32_t *minbits, unsigned long_long *minval) { unsigned i; if(type == t_uchar) { unsigned char *buf = data, min = 0, max = 0, span, filval = 0, filval_mask = 0; if(filavail == H5Z_SCALEOFFSET_FILL_DEFINED) { /* fill value defined */ /* retrieve fill value from corresponding positions of cd_values[] * retrieve them corresponding to how they are stored */ for(i = 0; i < sizeof(unsigned char); i++) { filval_mask = ((unsigned char *)filval_buf)[i]; filval_mask <<= i*8; filval |= filval_mask; } if(*minbits == 0) { /* minbits not set yet, calculate max, min, and minbits */ i = 0; while(i < d_nelmts && buf[i]== filval) i++; if(i < d_nelmts) min = max = buf[i]; for(; i < d_nelmts; i++) { if(buf[i] == filval) continue; /* ignore fill value */ if(buf[i] > max) max = buf[i]; if(buf[i] < min) min = buf[i]; } if(max - min > (unsigned char)(~(unsigned char)0 - 2)) { *minbits = sizeof(unsigned char)*8; *minval = min; return; } span = max - min + 1; *minbits = H5Z_scaleoffset_log2(span+1); } else { /* minbits already set, only calculate min */ i = 0; while(i < d_nelmts && buf[i]== filval) i++; if(i < d_nelmts) min = buf[i]; for(; i < d_nelmts; i++) { if(buf[i] == filval) continue; /* ignore fill value */ if(buf[i] < min) min = buf[i]; } } *minval = min; if(*minbits != sizeof(unsigned char)*8) /* change values if minbits != full precision */ for(i = 0; i < d_nelmts; i++) buf[i] = (buf[i] == filval)?(((unsigned char)1 << *minbits) - 1):(buf[i] - min); } else { /* fill value undefined */ if(*minbits == 0) { /* minbits not set yet, calculate max, min, and minbits */ min = max = buf[0]; for(i = 0; i < d_nelmts; i++) { if(buf[i] > max) max = buf[i]; if(buf[i] < min) min = buf[i]; } if(max - min > (unsigned char)(~(unsigned char)0 - 2)) { *minbits = sizeof(unsigned char)*8; *minval = min; return; } span = max - min + 1; *minbits = H5Z_scaleoffset_log2(span); } else { /* minbits already set, only calculate min */ min = buf[0]; for(i = 0; i < d_nelmts; i++) if(buf[i] < min) min = buf[i]; } *minval = min; if(*minbits != sizeof(unsigned char)*8) /* change values if minbits != full precision */ for(i = 0; i < d_nelmts; i++) buf[i] -= min; } } else if(type == t_ushort) { unsigned short *buf = data, min = 0, max = 0, span, filval = 0, filval_mask = 0; if(filavail == H5Z_SCALEOFFSET_FILL_DEFINED) { /* fill value defined */ /* retrieve fill value from corresponding positions of cd_values[] * retrieve them corresponding to how they are stored */ for(i = 0; i < sizeof(unsigned short); i++) { filval_mask = ((unsigned char *)filval_buf)[i]; filval_mask <<= i*8; filval |= filval_mask; } if(*minbits == 0) { /* minbits not set yet, calculate max, min, and minbits */ i = 0; while(i < d_nelmts && buf[i]== filval) i++; if(i < d_nelmts) min = max = buf[i]; for(; i < d_nelmts; i++) { if(buf[i] == filval) continue; /* ignore fill value */ if(buf[i] > max) max = buf[i]; if(buf[i] < min) min = buf[i]; } if(max - min > (unsigned short)(~(unsigned short)0 - 2)) { *minbits = sizeof(unsigned short)*8; *minval = min; return; } span = max - min + 1; *minbits = H5Z_scaleoffset_log2(span+1); } else { /* minbits already set, only calculate min */ i = 0; while(i < d_nelmts && buf[i]== filval) i++; if(i < d_nelmts) min = buf[i]; for(; i < d_nelmts; i++) { if(buf[i] == filval) continue; /* ignore fill value */ if(buf[i] < min) min = buf[i]; } } *minval = min; if(*minbits != sizeof(unsigned short)*8) /* change values if minbits != full precision */ for(i = 0; i < d_nelmts; i++) buf[i] = (buf[i] == filval)?(((unsigned short)1 << *minbits) - 1):(buf[i] - min); } else { /* fill value undefined */ if(*minbits == 0) { /* minbits not set yet, calculate max, min, and minbits */ min = max = buf[0]; for(i = 0; i < d_nelmts; i++) { if(buf[i] > max) max = buf[i]; if(buf[i] < min) min = buf[i]; } if(max - min > (unsigned short)(~(unsigned short)0 - 2)) { *minbits = sizeof(unsigned short)*8; *minval = min; return; } span = max - min + 1; *minbits = H5Z_scaleoffset_log2(span); } else { /* minbits already set, only calculate min */ min = buf[0]; for(i = 0; i < d_nelmts; i++) if(buf[i] < min) min = buf[i]; } *minval = min; if(*minbits != sizeof(unsigned short)*8) /* change values if minbits != full precision */ for(i = 0; i < d_nelmts; i++) buf[i] -= min; } } else if(type == t_uint) { unsigned int *buf = data, min = 0, max = 0, span, filval = 0, filval_mask = 0; if(filavail == H5Z_SCALEOFFSET_FILL_DEFINED) { /* fill value defined */ /* retrieve fill value from corresponding positions of cd_values[] * retrieve them corresponding to how they are stored */ for(i = 0; i < sizeof(unsigned int); i++) { filval_mask = ((unsigned char *)filval_buf)[i]; filval_mask <<= i*8; filval |= filval_mask; } if(*minbits == 0) { /* minbits not set yet, calculate max, min, and minbits */ i = 0; while(i < d_nelmts && buf[i]== filval) i++; if(i < d_nelmts) min = max = buf[i]; for(; i < d_nelmts; i++) { if(buf[i] == filval) continue; /* ignore fill value */ if(buf[i] > max) max = buf[i]; if(buf[i] < min) min = buf[i]; } if(max - min > ~(unsigned int)0 - 2) { *minbits = sizeof(unsigned int)*8; *minval = min; return; } span = max - min + 1; *minbits = H5Z_scaleoffset_log2(span+1); } else { /* minbits already set, only calculate min */ i = 0; while(i < d_nelmts && buf[i]== filval) i++; if(i < d_nelmts) min = buf[i]; for(; i < d_nelmts; i++) { if(buf[i] == filval) continue; /* ignore fill value */ if(buf[i] < min) min = buf[i]; } } *minval = min; if(*minbits != sizeof(unsigned int)*8) /* change values if minbits != full precision */ for(i = 0; i < d_nelmts; i++) buf[i] = (buf[i] == filval)?(((unsigned int)1 << *minbits) - 1):(buf[i] - min); } else { /* fill value undefined */ if(*minbits == 0) { /* minbits not set yet, calculate max, min, and minbits */ min = max = buf[0]; for(i = 0; i < d_nelmts; i++) { if(buf[i] > max) max = buf[i]; if(buf[i] < min) min = buf[i]; } if(max - min > ~(unsigned int)0 - 2) { *minbits = sizeof(unsigned int)*8; *minval = min; return; } span = max - min + 1; *minbits = H5Z_scaleoffset_log2(span); } else { /* minbits already set, only calculate min */ min = buf[0]; for(i = 0; i < d_nelmts; i++) if(buf[i] < min) min = buf[i]; } *minval = min; if(*minbits != sizeof(unsigned int)*8) /* change values if minbits != full precision */ for(i = 0; i < d_nelmts; i++) buf[i] -= min; } } else if(type == t_ulong) { unsigned long *buf = data, min = 0, max = 0, span, filval = 0, filval_mask = 0; if(filavail == H5Z_SCALEOFFSET_FILL_DEFINED) { /* fill value defined */ /* retrieve fill value from corresponding positions of cd_values[] * retrieve them corresponding to how they are stored */ for(i = 0; i < sizeof(unsigned long); i++) { filval_mask = ((unsigned char *)filval_buf)[i]; filval_mask <<= i*8; filval |= filval_mask; } if(*minbits == 0) { /* minbits not set yet, calculate max, min, and minbits */ i = 0; while(i < d_nelmts && buf[i]== filval) i++; if(i < d_nelmts) min = max = buf[i]; for(; i < d_nelmts; i++) { if(buf[i] == filval) continue; /* ignore fill value */ if(buf[i] > max) max = buf[i]; if(buf[i] < min) min = buf[i]; } if(max - min > ~(unsigned long)0 - 2) { *minbits = sizeof(unsigned long)*8; *minval = min; return; } span = max - min + 1; *minbits = H5Z_scaleoffset_log2(span+1); } else { /* minbits already set, only calculate min */ i = 0; while(i < d_nelmts && buf[i]== filval) i++; if(i < d_nelmts) min = buf[i]; for(; i < d_nelmts; i++) { if(buf[i] == filval) continue; /* ignore fill value */ if(buf[i] < min) min = buf[i]; } } *minval = min; if(*minbits != sizeof(unsigned long)*8) /* change values if minbits != full precision */ for(i = 0; i < d_nelmts; i++) buf[i] = (buf[i] == filval)?(((unsigned long)1 << *minbits) - 1):(buf[i] - min); } else { /* fill value undefined */ if(*minbits == 0) { /* minbits not set yet, calculate max, min, and minbits */ min = max = buf[0]; for(i = 0; i < d_nelmts; i++) { if(buf[i] > max) max = buf[i]; if(buf[i] < min) min = buf[i]; } if(max - min > ~(unsigned long)0 - 2) { *minbits = sizeof(unsigned long)*8; *minval = min; return; } span = max - min + 1; *minbits = H5Z_scaleoffset_log2(span); } else { /* minbits already set, only calculate min */ min = buf[0]; for(i = 0; i < d_nelmts; i++) if(buf[i] < min) min = buf[i]; } *minval = min; if(*minbits != sizeof(unsigned long)*8) /* change values if minbits != full precision */ for(i = 0; i < d_nelmts; i++) buf[i] -= min; } } else if(type == t_ulong_long) { unsigned long_long *buf = data, min = 0, max = 0, span, filval = 0, filval_mask = 0; if(filavail == H5Z_SCALEOFFSET_FILL_DEFINED) { /* fill value defined */ /* retrieve fill value from corresponding positions of cd_values[] * retrieve them corresponding to how they are stored */ for(i = 0; i < sizeof(unsigned long_long); i++) { filval_mask = ((unsigned char *)filval_buf)[i]; filval_mask <<= i*8; filval |= filval_mask; } if(*minbits == 0) { /* minbits not set yet, calculate max, min, and minbits */ i = 0; while(i < d_nelmts && buf[i]== filval) i++; if(i < d_nelmts) min = max = buf[i]; for(; i < d_nelmts; i++) { if(buf[i] == filval) continue; /* ignore fill value */ if(buf[i] > max) max = buf[i]; if(buf[i] < min) min = buf[i]; } if(max - min > ~(unsigned long_long)0 - 2) { *minbits = sizeof(unsigned long_long)*8; *minval = min; return; } span = max - min + 1; *minbits = H5Z_scaleoffset_log2(span+1); } else { /* minbits already set, only calculate min */ i = 0; while(i < d_nelmts && buf[i]== filval) i++; if(i < d_nelmts) min = buf[i]; for(; i < d_nelmts; i++) { if(buf[i] == filval) continue; /* ignore fill value */ if(buf[i] < min) min = buf[i]; } } *minval = min; if(*minbits != sizeof(unsigned long_long)*8) /* change values if minbits != full precision */ for(i = 0; i < d_nelmts; i++) buf[i] = (buf[i] == filval)?(((unsigned long_long)1 << *minbits) - 1):(buf[i] - min); } else { /* fill value undefined */ if(*minbits == 0) { /* minbits not set yet, calculate max, min, and minbits */ min = max = buf[0]; for(i = 0; i < d_nelmts; i++) { if(buf[i] > max) max = buf[i]; if(buf[i] < min) min = buf[i]; } if(max - min > ~(unsigned long_long)0 - 2) { *minbits = sizeof(unsigned long_long)*8; *minval = min; return; } span = max - min + 1; *minbits = H5Z_scaleoffset_log2(span); } else { /* minbits already set, only calculate min */ min = buf[0]; for(i = 0; i < d_nelmts; i++) if(buf[i] < min) min = buf[i]; } *minval = min; if(*minbits != sizeof(unsigned long_long)*8) /* change values if minbits != full precision */ for(i = 0; i < d_nelmts; i++) buf[i] -= min; } } else if(type == t_schar) { signed char *buf = data, min = 0, max = 0, filval = 0, filval_mask = 0; unsigned char span; if(filavail == H5Z_SCALEOFFSET_FILL_DEFINED) { /* fill value defined */ /* retrieve fill value from corresponding positions of cd_values[] * retrieve them corresponding to how they are stored */ for(i = 0; i < sizeof(signed char); i++) { filval_mask = ((unsigned char *)filval_buf)[i]; filval_mask <<= i*8; filval |= filval_mask; } if(*minbits == 0) { /* minbits not set yet, calculate max, min, and minbits */ i = 0; while(i < d_nelmts && buf[i]== filval) i++; if(i < d_nelmts) min = max = buf[i]; for(; i < d_nelmts; i++) { if(buf[i] == filval) continue; /* ignore fill value */ if(buf[i] > max) max = buf[i]; if(buf[i] < min) min = buf[i]; } if((unsigned char)(max - min) > (unsigned char)(~(unsigned char)0 - 2)) { *minbits = sizeof(signed char)*8; *minval = min; return; } span = max - min + 1; *minbits = H5Z_scaleoffset_log2(span+1); } else { /* minbits already set, only calculate min */ i = 0; while(i < d_nelmts && buf[i]== filval) i++; if(i < d_nelmts) min = buf[i]; for(; i < d_nelmts; i++) { if(buf[i] == filval) continue; /* ignore fill value */ if(buf[i] < min) min = buf[i]; } } *minval = min; if(*minbits != sizeof(signed char)*8) /* change values if minbits != full precision */ for(i = 0; i < d_nelmts; i++) buf[i] = (buf[i] == filval)?(((unsigned char)1 << *minbits) - 1):(buf[i] - min); } else { /* fill value undefined */ if(*minbits == 0) { /* minbits not set yet, calculate max, min, and minbits */ min = max = buf[0]; for(i = 0; i < d_nelmts; i++) { if(buf[i] > max) max = buf[i]; if(buf[i] < min) min = buf[i]; } if((unsigned char)(max - min) > (unsigned char)(~(unsigned char)0 - 2)) { *minbits = sizeof(signed char)*8; *minval = min; return; } span = max - min + 1; *minbits = H5Z_scaleoffset_log2(span); } else { /* minbits already set, only calculate min */ min = buf[0]; for(i = 0; i < d_nelmts; i++) if(buf[i] < min) min = buf[i]; } *minval = min; if(*minbits != sizeof(signed char)*8) /* change values if minbits != full precision */ for(i = 0; i < d_nelmts; i++) buf[i] -= min; } } else if(type == t_short) { short *buf = data, min = 0, max = 0, filval = 0, filval_mask = 0; unsigned short span; if(filavail == H5Z_SCALEOFFSET_FILL_DEFINED) { /* fill value defined */ /* retrieve fill value from corresponding positions of cd_values[] * retrieve them corresponding to how they are stored */ for(i = 0; i < sizeof(short); i++) { filval_mask = ((unsigned char *)filval_buf)[i]; filval_mask <<= i*8; filval |= filval_mask; } if(*minbits == 0) { /* minbits not set yet, calculate max, min, and minbits */ i = 0; while(i < d_nelmts && buf[i]== filval) i++; if(i < d_nelmts) min = max = buf[i]; for(; i < d_nelmts; i++) { if(buf[i] == filval) continue; /* ignore fill value */ if(buf[i] > max) max = buf[i]; if(buf[i] < min) min = buf[i]; } if((unsigned short)(max - min) > (unsigned short)(~(unsigned short)0 - 2)) { *minbits = sizeof(short)*8; *minval = min; return; } span = max - min + 1; *minbits = H5Z_scaleoffset_log2(span+1); } else { /* minbits already set, only calculate min */ i = 0; while(i < d_nelmts && buf[i]== filval) i++; if(i < d_nelmts) min = buf[i]; for(; i < d_nelmts; i++) { if(buf[i] == filval) continue; /* ignore fill value */ if(buf[i] < min) min = buf[i]; } } *minval = min; if(*minbits != sizeof(short)*8) /* change values if minbits != full precision */ for(i = 0; i < d_nelmts; i++) buf[i] = (buf[i] == filval)?(((unsigned short)1 << *minbits) - 1):(buf[i] - min); } else { /* fill value undefined */ if(*minbits == 0) { /* minbits not set yet, calculate max, min, and minbits */ min = max = buf[0]; for(i = 0; i < d_nelmts; i++) { if(buf[i] > max) max = buf[i]; if(buf[i] < min) min = buf[i]; } if((unsigned short)(max - min) > (unsigned short)(~(unsigned short)0 - 2)) { *minbits = sizeof(short)*8; *minval = min; return; } span = max - min + 1; *minbits = H5Z_scaleoffset_log2(span); } else { /* minbits already set, only calculate min */ min = buf[0]; for(i = 0; i < d_nelmts; i++) if(buf[i] < min) min = buf[i]; } *minval = min; if(*minbits != sizeof(short)*8) /* change values if minbits != full precision */ for(i = 0; i < d_nelmts; i++) buf[i] -= min; } } else if(type == t_int) { int *buf = data, min = 0, max = 0, filval = 0, filval_mask = 0; unsigned int span; if(filavail == H5Z_SCALEOFFSET_FILL_DEFINED) { /* fill value defined */ /* retrieve fill value from corresponding positions of cd_values[] * retrieve them corresponding to how they are stored */ for(i = 0; i < sizeof(int); i++) { filval_mask = ((unsigned char *)filval_buf)[i]; filval_mask <<= i*8; filval |= filval_mask; } if(*minbits == 0) { /* minbits not set yet, calculate max, min, and minbits */ i = 0; while(i < d_nelmts && buf[i]== filval) i++; if(i < d_nelmts) min = max = buf[i]; for(; i < d_nelmts; i++) { if(buf[i] == filval) continue; /* ignore fill value */ if(buf[i] > max) max = buf[i]; if(buf[i] < min) min = buf[i]; } if((unsigned int)(max - min) > ~(unsigned int)0 - 2) { *minbits = sizeof(int)*8; *minval = min; return; } span = max - min + 1; *minbits = H5Z_scaleoffset_log2(span+1); } else { /* minbits already set, only calculate min */ i = 0; while(i < d_nelmts && buf[i]== filval) i++; if(i < d_nelmts) min = buf[i]; for(; i < d_nelmts; i++) { if(buf[i] == filval) continue; /* ignore fill value */ if(buf[i] < min) min = buf[i]; } } *minval = min; if(*minbits != sizeof(int)*8) /* change values if minbits != full precision */ for(i = 0; i < d_nelmts; i++) buf[i] = (buf[i] == filval)?(((unsigned int)1 << *minbits) - 1):(buf[i] - min); } else { /* fill value undefined */ if(*minbits == 0) { /* minbits not set yet, calculate max, min, and minbits */ min = max = buf[0]; for(i = 0; i < d_nelmts; i++) { if(buf[i] > max) max = buf[i]; if(buf[i] < min) min = buf[i]; } if((unsigned int)(max - min) > ~(unsigned int)0 - 2) { *minbits = sizeof(int)*8; *minval = min; return; } span = max - min + 1; *minbits = H5Z_scaleoffset_log2(span); } else { /* minbits already set, only calculate min */ min = buf[0]; for(i = 0; i < d_nelmts; i++) if(buf[i] < min) min = buf[i]; } *minval = min; if(*minbits != sizeof(int)*8) /* change values if minbits != full precision */ for(i = 0; i < d_nelmts; i++) buf[i] -= min; } } else if(type == t_long) { long *buf = data, min = 0, max = 0, filval = 0, filval_mask = 0; unsigned long span; if(filavail == H5Z_SCALEOFFSET_FILL_DEFINED) { /* fill value defined */ /* retrieve fill value from corresponding positions of cd_values[] * retrieve them corresponding to how they are stored */ for(i = 0; i < sizeof(long); i++) { filval_mask = ((unsigned char *)filval_buf)[i]; filval_mask <<= i*8; filval |= filval_mask; } if(*minbits == 0) { /* minbits not set yet, calculate max, min, and minbits */ i = 0; while(i < d_nelmts && buf[i]== filval) i++; if(i < d_nelmts) min = max = buf[i]; for(; i < d_nelmts; i++) { if(buf[i] == filval) continue; /* ignore fill value */ if(buf[i] > max) max = buf[i]; if(buf[i] < min) min = buf[i]; } if((unsigned long)(max - min) > ~(unsigned long)0 - 2) { *minbits = sizeof(long)*8; *minval = min; return; } span = max - min + 1; *minbits = H5Z_scaleoffset_log2(span+1); } else { /* minbits already set, only calculate min */ i = 0; while(i < d_nelmts && buf[i]== filval) i++; if(i < d_nelmts) min = buf[i]; for(; i < d_nelmts; i++) { if(buf[i] == filval) continue; /* ignore fill value */ if(buf[i] < min) min = buf[i]; } } *minval = min; if(*minbits != sizeof(long)*8) /* change values if minbits != full precision */ for(i = 0; i < d_nelmts; i++) buf[i] = (buf[i] == filval)?(((unsigned long)1 << *minbits) - 1):(buf[i] - min); } else { /* fill value undefined */ if(*minbits == 0) { /* minbits not set yet, calculate max, min, and minbits */ min = max = buf[0]; for(i = 0; i < d_nelmts; i++) { if(buf[i] > max) max = buf[i]; if(buf[i] < min) min = buf[i]; } if((unsigned long)(max - min) > ~(unsigned long)0 - 2) { *minbits = sizeof(long)*8; *minval = min; return; } span = max - min + 1; *minbits = H5Z_scaleoffset_log2(span); } else { /* minbits already set, only calculate min */ min = buf[0]; for(i = 0; i < d_nelmts; i++) if(buf[i] < min) min = buf[i]; } *minval = min; if(*minbits != sizeof(long)*8) /* change values if minbits != full precision */ for(i = 0; i < d_nelmts; i++) buf[i] -= min; } } else if(type == t_long_long) { long_long *buf = data, min = 0, max = 0, filval = 0, filval_mask = 0; unsigned long_long span; if(filavail == H5Z_SCALEOFFSET_FILL_DEFINED) { /* fill value defined */ /* retrieve fill value from corresponding positions of cd_values[] * retrieve them corresponding to how they are stored */ for(i = 0; i < sizeof(long_long); i++) { filval_mask = ((unsigned char *)filval_buf)[i]; filval_mask <<= i*8; filval |= filval_mask; } if(*minbits == 0) { /* minbits not set yet, calculate max, min, and minbits */ i = 0; while(i < d_nelmts && buf[i]== filval) i++; if(i < d_nelmts) min = max = buf[i]; for(; i < d_nelmts; i++) { if(buf[i] == filval) continue; /* ignore fill value */ if(buf[i] > max) max = buf[i]; if(buf[i] < min) min = buf[i]; } if((unsigned long_long)(max - min) > ~(unsigned long_long)0 - 2) { *minbits = sizeof(long_long)*8; *minval = min; return; } span = max - min + 1; *minbits = H5Z_scaleoffset_log2(span+1); } else { /* minbits already set, only calculate min */ i = 0; while(i < d_nelmts && buf[i]== filval) i++; if(i < d_nelmts) min = buf[i]; for(; i < d_nelmts; i++) { if(buf[i] == filval) continue; /* ignore fill value */ if(buf[i] < min) min = buf[i]; } } *minval = min; if(*minbits != sizeof(long_long)*8) /* change values if minbits != full precision */ for(i = 0; i < d_nelmts; i++) buf[i] = (buf[i] == filval)?(((unsigned long_long)1 << *minbits) - 1):(buf[i] - min); } else { /* fill value undefined */ if(*minbits == 0) { /* minbits not set yet, calculate max, min, and minbits */ min = max = buf[0]; for(i = 0; i < d_nelmts; i++) { if(buf[i] > max) max = buf[i]; if(buf[i] < min) min = buf[i]; } if((unsigned long_long)(max - min) > ~(unsigned long_long)0 - 2) { *minbits = sizeof(long_long)*8; *minval = min; return; } span = max - min + 1; *minbits = H5Z_scaleoffset_log2(span); } else { /* minbits already set, only calculate min */ min = buf[0]; for(i = 0; i < d_nelmts; i++) if(buf[i] < min) min = buf[i]; } *minval = min; if(*minbits != sizeof(long_long)*8) /* change values if minbits != full precision */ for(i = 0; i < d_nelmts; i++) buf[i] -= min; } } } static void H5Z_scaleoffset_postdecompress(void *data, unsigned d_nelmts, enum H5Z_scaleoffset_type type, unsigned filavail, void *filval_buf, uint32_t minbits, unsigned long_long minval) { unsigned i; long_long sminval = *(long_long*)&minval; /* for signed integer types */ if(type == t_uchar) { unsigned char *buf = data, filval = 0, filval_mask = 0; if(filavail == H5Z_SCALEOFFSET_FILL_DEFINED) { /* fill value defined */ /* retrieve fill value from corresponding positions of cd_values[] * retrieve them corresponding to how they are stored */ for(i = 0; i < sizeof(unsigned char); i++) { filval_mask = ((unsigned char *)filval_buf)[i]; filval_mask <<= i*8; filval |= filval_mask; } for(i = 0; i < d_nelmts; i++) buf[i] = (buf[i] == (((unsigned char)1 << minbits) - 1))?filval:(buf[i] + minval); } else /* fill value undefined */ for(i = 0; i < d_nelmts; i++) buf[i] += minval; } else if(type == t_ushort) { unsigned short *buf = data, filval = 0, filval_mask = 0; if(filavail == H5Z_SCALEOFFSET_FILL_DEFINED) { /* fill value defined */ /* retrieve fill value from corresponding positions of cd_values[] * retrieve them corresponding to how they are stored */ for(i = 0; i < sizeof(unsigned short); i++) { filval_mask = ((unsigned char *)filval_buf)[i]; filval_mask <<= i*8; filval |= filval_mask; } for(i = 0; i < d_nelmts; i++) buf[i] = (buf[i] == (((unsigned short)1 << minbits) - 1))?filval:(buf[i] + minval); } else /* fill value undefined */ for(i = 0; i < d_nelmts; i++) buf[i] += minval; } else if(type == t_uint) { unsigned int *buf = data, filval = 0, filval_mask = 0; if(filavail == H5Z_SCALEOFFSET_FILL_DEFINED) { /* fill value defined */ /* retrieve fill value from corresponding positions of cd_values[] * retrieve them corresponding to how they are stored */ for(i = 0; i < sizeof(unsigned int); i++) { filval_mask = ((unsigned char *)filval_buf)[i]; filval_mask <<= i*8; filval |= filval_mask; } for(i = 0; i < d_nelmts; i++) buf[i] = (buf[i] == (((unsigned int)1 << minbits) - 1))?filval:(buf[i] + minval); } else /* fill value undefined */ for(i = 0; i < d_nelmts; i++) buf[i] += minval; } else if(type == t_ulong) { unsigned long *buf = data, filval = 0, filval_mask = 0; if(filavail == H5Z_SCALEOFFSET_FILL_DEFINED) { /* fill value defined */ /* retrieve fill value from corresponding positions of cd_values[] * retrieve them corresponding to how they are stored */ for(i = 0; i < sizeof(unsigned long); i++) { filval_mask = ((unsigned char *)filval_buf)[i]; filval_mask <<= i*8; filval |= filval_mask; } for(i = 0; i < d_nelmts; i++) buf[i] = (buf[i] == (((unsigned long)1 << minbits) - 1))?filval:(buf[i] + minval); } else /* fill value undefined */ for(i = 0; i < d_nelmts; i++) buf[i] += minval; } else if(type == t_ulong_long) { unsigned long_long *buf = data, filval = 0, filval_mask = 0; if(filavail == H5Z_SCALEOFFSET_FILL_DEFINED) { /* fill value defined */ /* retrieve fill value from corresponding positions of cd_values[] * retrieve them corresponding to how they are stored */ for(i = 0; i < sizeof(unsigned long_long); i++) { filval_mask = ((unsigned char *)filval_buf)[i]; filval_mask <<= i*8; filval |= filval_mask; } for(i = 0; i < d_nelmts; i++) buf[i] = (buf[i] == (((unsigned long_long)1 << minbits) - 1))?filval:(buf[i] + minval); } else /* fill value undefined */ for(i = 0; i < d_nelmts; i++) buf[i] += minval; } else if(type == t_schar) { signed char *buf = data, filval = 0, filval_mask = 0; if(filavail == H5Z_SCALEOFFSET_FILL_DEFINED) { /* fill value defined */ /* retrieve fill value from corresponding positions of cd_values[] * retrieve them corresponding to how they are stored */ for(i = 0; i < sizeof(signed char); i++) { filval_mask = ((unsigned char *)filval_buf)[i]; filval_mask <<= i*8; filval |= filval_mask; } for(i = 0; i < d_nelmts; i++) buf[i] = (buf[i] == (((unsigned char)1 << minbits) - 1))?filval:(buf[i] + sminval); } else /* fill value undefined */ for(i = 0; i < d_nelmts; i++) buf[i] += sminval; } else if(type == t_short) { short *buf = data, filval = 0, filval_mask = 0; if(filavail == H5Z_SCALEOFFSET_FILL_DEFINED) { /* fill value defined */ /* retrieve fill value from corresponding positions of cd_values[] * retrieve them corresponding to how they are stored */ for(i = 0; i < sizeof(short); i++) { filval_mask = ((unsigned char *)filval_buf)[i]; filval_mask <<= i*8; filval |= filval_mask; } for(i = 0; i < d_nelmts; i++) buf[i] = (buf[i] == (((unsigned short)1 << minbits) - 1))?filval:(buf[i] + sminval); } else /* fill value undefined */ for(i = 0; i < d_nelmts; i++) buf[i] += sminval; } else if(type == t_int) { int *buf = data, filval = 0, filval_mask = 0; if(filavail == H5Z_SCALEOFFSET_FILL_DEFINED) { /* fill value defined */ /* retrieve fill value from corresponding positions of cd_values[] * retrieve them corresponding to how they are stored */ for(i = 0; i < sizeof(int); i++) { filval_mask = ((unsigned char *)filval_buf)[i]; filval_mask <<= i*8; filval |= filval_mask; } for(i = 0; i < d_nelmts; i++) buf[i] = (buf[i] == (((unsigned int)1 << minbits) - 1))?filval:(buf[i] + sminval); } else /* fill value undefined */ for(i = 0; i < d_nelmts; i++) buf[i] += sminval; } else if(type == t_long) { long *buf = data, filval = 0, filval_mask = 0; if(filavail == H5Z_SCALEOFFSET_FILL_DEFINED) { /* fill value defined */ /* retrieve fill value from corresponding positions of cd_values[] * retrieve them corresponding to how they are stored */ for(i = 0; i < sizeof(long); i++) { filval_mask = ((unsigned char *)filval_buf)[i]; filval_mask <<= i*8; filval |= filval_mask; } for(i = 0; i < d_nelmts; i++) buf[i] = (buf[i] == (((unsigned long)1 << minbits) - 1))?filval:(buf[i] + sminval); } else /* fill value undefined */ for(i = 0; i < d_nelmts; i++) buf[i] += sminval; } else if(type == t_long_long) { long_long *buf = data, filval = 0, filval_mask = 0; if(filavail == H5Z_SCALEOFFSET_FILL_DEFINED) { /* fill value defined */ /* retrieve fill value from corresponding positions of cd_values[] * retrieve them corresponding to how they are stored */ for(i = 0; i < sizeof(long_long); i++) { filval_mask = ((unsigned char *)filval_buf)[i]; filval_mask <<= i*8; filval |= filval_mask; } for(i = 0; i < d_nelmts; i++) buf[i] = (buf[i] == (((unsigned long_long)1 << minbits) - 1))?filval:(buf[i] + sminval); } else /* fill value undefined */ for(i = 0; i < d_nelmts; i++) buf[i] += sminval; } } static void H5Z_scaleoffset_next_byte(size_t *j, int *buf_len) { ++(*j); *buf_len = 8 * sizeof(unsigned char); } static void H5Z_scaleoffset_decompress_one_byte(unsigned char *data, size_t data_offset, int k, int begin_i, unsigned char *buffer, size_t *j, int *buf_len, parms_atomic p, int dtype_len) { int dat_len; /* dat_len is the number of bits to be copied in each data byte */ unsigned char val; /* value to be copied in each data byte */ /* initialize value and bits of unsigned char to be copied */ val = buffer[*j]; if(k == begin_i) dat_len = 8 - (dtype_len - p.minbits) % 8; else dat_len = 8; if(*buf_len > dat_len) { data[data_offset + k] = ((val >> (*buf_len - dat_len)) & ~(~0 << dat_len)); *buf_len -= dat_len; } else { data[data_offset + k] = ((val & ~(~0 << *buf_len)) << (dat_len - *buf_len)); dat_len -= *buf_len; H5Z_scaleoffset_next_byte(j, buf_len); if(dat_len == 0) return; val = buffer[*j]; data[data_offset + k] |= ((val >> (*buf_len - dat_len)) & ~(~0 << dat_len)); *buf_len -= dat_len; } } static void H5Z_scaleoffset_decompress_one_atomic(unsigned char *data, size_t data_offset, unsigned char *buffer, size_t *j, int *buf_len, parms_atomic p) { /* begin_i: the index of byte having first significant bit */ int k, begin_i, dtype_len; assert(p.minbits > 0); dtype_len = p.size * 8; if(p.mem_order == H5Z_SCALEOFFSET_ORDER_LE) { /* little endian */ begin_i = p.size - 1 - (dtype_len - p.minbits) / 8; for(k = begin_i; k >= 0; k--) H5Z_scaleoffset_decompress_one_byte(data, data_offset, k, begin_i, buffer, j, buf_len, p, dtype_len); } if(p.mem_order == H5Z_SCALEOFFSET_ORDER_BE) { /* big endian */ begin_i = (dtype_len - p.minbits) / 8; for(k = begin_i; k <= p.size - 1; k++) H5Z_scaleoffset_decompress_one_byte(data, data_offset, k, begin_i, buffer, j, buf_len, p, dtype_len); } } static void H5Z_scaleoffset_decompress(unsigned char *data, unsigned d_nelmts, unsigned char *buffer, parms_atomic p) { /* i: index of data, j: index of buffer, buf_len: number of bits to be filled in current byte */ size_t i, j; int buf_len; /* must initialize to zeros */ for(i = 0; i < d_nelmts*p.size; i++) data[i] = 0; /* initialization before the loop */ j = 0; buf_len = sizeof(unsigned char) * 8; /* decompress */ for(i = 0; i < d_nelmts; i++) H5Z_scaleoffset_decompress_one_atomic(data, i*p.size, buffer, &j, &buf_len, p); } static void H5Z_scaleoffset_compress_one_byte(unsigned char *data, size_t data_offset, int k, int begin_i, unsigned char *buffer, size_t *j, int *buf_len, parms_atomic p, int dtype_len) { int dat_len; /* dat_len is the number of bits to be copied in each data byte */ unsigned char val; /* value to be copied in each data byte */ /* initialize value and bits of unsigned char to be copied */ val = data[data_offset + k]; if(k == begin_i) dat_len = 8 - (dtype_len - p.minbits) % 8; else dat_len = 8; if(*buf_len > dat_len) { buffer[*j] |= (val & ~(~0 << dat_len)) << (*buf_len - dat_len); *buf_len -= dat_len; } else { buffer[*j] |= (val >> (dat_len - *buf_len)) & ~(~0 << *buf_len); dat_len -= *buf_len; H5Z_scaleoffset_next_byte(j, buf_len); if(dat_len == 0) return; buffer[*j] = (val & ~(~0 << dat_len)) << (*buf_len - dat_len); *buf_len -= dat_len; } } static void H5Z_scaleoffset_compress_one_atomic(unsigned char *data, size_t data_offset, unsigned char *buffer, size_t *j, int *buf_len, parms_atomic p) { /* begin_i: the index of byte having first significant bit */ int k, begin_i, dtype_len; assert(p.minbits > 0); dtype_len = p.size * 8; if(p.mem_order == H5Z_SCALEOFFSET_ORDER_LE) { /* little endian */ begin_i = p.size - 1 - (dtype_len - p.minbits) / 8; for(k = begin_i; k >= 0; k--) H5Z_scaleoffset_compress_one_byte(data, data_offset, k, begin_i, buffer, j, buf_len, p, dtype_len); } if(p.mem_order == H5Z_SCALEOFFSET_ORDER_BE) { /* big endian */ begin_i = (dtype_len - p.minbits) / 8; for(k = begin_i; k <= p.size - 1; k++) H5Z_scaleoffset_compress_one_byte(data, data_offset, k, begin_i, buffer, j, buf_len, p, dtype_len); } } static void H5Z_scaleoffset_compress(unsigned char *data, unsigned d_nelmts, unsigned char *buffer, size_t buffer_size, parms_atomic p) { /* i: index of data, j: index of buffer, buf_len: number of bits to be filled in current byte */ size_t i, j; int buf_len; /* must initialize buffer to be zeros */ for(j = 0; j < buffer_size; j++) buffer[j] = 0; /* initialization before the loop */ j = 0; buf_len = sizeof(unsigned char) * 8; /* compress */ for(i = 0; i < d_nelmts; i++) H5Z_scaleoffset_compress_one_atomic(data, i*p.size, buffer, &j, &buf_len, p); } #endif /* H5_HAVE_FILTER_SCALEOFFSET */