diff options
Diffstat (limited to 'src/H5Tbit.c')
| -rw-r--r-- | src/H5Tbit.c | 119 |
1 files changed, 117 insertions, 2 deletions
diff --git a/src/H5Tbit.c b/src/H5Tbit.c index 157da5d..d063137 100644 --- a/src/H5Tbit.c +++ b/src/H5Tbit.c @@ -78,7 +78,7 @@ H5T_bit_copy (uint8_t *dst, size_t dst_offset, const uint8_t *src, * ... v v v v v V V V V V * ...+---------------+---------------+ * ...|7 6 5 4 3 2 1 0|7 6 5 4 3 2 1 0| - * ...+---------------+---------------+ + ...+---------------+---------------+ * dst[d_idx+1] dst[d_idx] */ while (src_offset && size>0) { @@ -161,6 +161,59 @@ H5T_bit_copy (uint8_t *dst, size_t dst_offset, const uint8_t *src, /*------------------------------------------------------------------------- + * Function: H5T_bit_shift + * + * Purpose: Simulation of hardware shifting. Shifts a bit vector + * in a way similar to shifting a variable value, like + * value <<= 3, or value >>= 16. + * + * Return: void + * + * Programmer: Raymond Lu + * Wednesday, Febuary 4, 2004 + * + * Modifications: + * + *------------------------------------------------------------------------- + */ +void +H5T_bit_shift (uint8_t *buf, hssize_t shift_dist, size_t buf_size) +{ + uint8_t *tmp_buf; + size_t buf_size_bit = 8*buf_size; + size_t i; + + FUNC_ENTER_NOAPI_NOINIT(H5T_bit_shift); + + if(!shift_dist) + goto done; + if(abs(shift_dist) >= buf_size_bit) { + H5T_bit_set (buf, 0, buf_size_bit, FALSE); + goto done; + } + + tmp_buf = (uint8_t*)HDcalloc(buf_size, 1); + + /* Shift vector by making copies */ + if(shift_dist > 0) /* left shift */ + H5T_bit_copy (tmp_buf, shift_dist, buf, 0, buf_size_bit-shift_dist); + else { /* right shift */ + shift_dist = -shift_dist; + H5T_bit_copy(tmp_buf, 0, buf, shift_dist, buf_size_bit-shift_dist); + } + + /* Copy back the vector */ + for(i=0; i<buf_size; i++) + buf[i] = tmp_buf[i]; + + HDfree(tmp_buf); + +done: + FUNC_LEAVE_NOAPI_VOID +} + + +/*------------------------------------------------------------------------- * Function: H5T_bit_get_d * * Purpose: Return a small bit sequence as a number. @@ -439,7 +492,7 @@ H5T_bit_inc(uint8_t *buf, size_t start, size_t size) unsigned acc, mask; /* Use FUNC_ENTER_NOAPI_NOINIT_NOFUNC here to avoid performance issues */ - FUNC_ENTER_NOAPI_NOINIT_NOFUNC(H5T_bit_find); + FUNC_ENTER_NOAPI_NOINIT_NOFUNC(H5T_bit_inc); assert(buf); start %= 8; @@ -480,3 +533,65 @@ H5T_bit_inc(uint8_t *buf, size_t start, size_t size) FUNC_LEAVE_NOAPI(carry ? TRUE : FALSE); } + + +/*------------------------------------------------------------------------- + * Function: H5T_bit_dec + * + * Purpose: decrement part of a bit field by 1. + * At this moment, START is always 0 and the algorithm only + * works from the end to the front for the buffer. + * + * Return: void + * + * + * Programmer: Raymond Lu + * Wednesday, Jan 28, 2004 + * + * Modifications: + * + *------------------------------------------------------------------------- + */ +void +H5T_bit_dec(uint8_t *buf, size_t start, size_t size) +{ + size_t idx; + + assert(buf); + + for(idx=0; idx < size/8; idx++) { + if(buf[idx] != 0x00) { + buf[idx] -= 1; + break; + } else if(buf[idx]==0x00) { + buf[idx] -= 1; + } + } +} + + +/*------------------------------------------------------------------------- + * Function: H5T_bit_neg + * + * Purpose: Bit-negate buffer. + * At this moment, START is always 0. + * + * Return: void + * + * Programmer: Raymond Lu + * Wednesday, Jan 28, 2004 + * + * Modifications: + * + *------------------------------------------------------------------------- + */ +void +H5T_bit_neg(uint8_t *buf, size_t start, size_t size) +{ + size_t i; + + assert(buf); + + for(i=0; i<size/8; i++) + buf[i] = ~(buf[i]); +} |