diff options
Diffstat (limited to 'src/include/utils/numeric.h')
| -rw-r--r-- | src/include/utils/numeric.h | 24 |
1 files changed, 17 insertions, 7 deletions
diff --git a/src/include/utils/numeric.h b/src/include/utils/numeric.h index 42daf5e4a53..cd8ff13e289 100644 --- a/src/include/utils/numeric.h +++ b/src/include/utils/numeric.h @@ -5,7 +5,7 @@ * * 1998 Jan Wieck * - * $Header: /cvsroot/pgsql/src/include/utils/numeric.h,v 1.7 1999/07/14 01:20:30 momjian Exp $ + * $Header: /cvsroot/pgsql/src/include/utils/numeric.h,v 1.8 2000/01/15 23:42:48 tgl Exp $ * * ---------- */ @@ -21,31 +21,41 @@ #define NUMERIC_DEFAULT_PRECISION 30 #define NUMERIC_DEFAULT_SCALE 6 + +/* ---------- + * Internal limits on the scales chosen for calculation results + * ---------- + */ #define NUMERIC_MAX_DISPLAY_SCALE NUMERIC_MAX_PRECISION -#define NUMERIC_MIN_DISPLAY_SCALE NUMERIC_DEFAULT_SCALE + 4 +#define NUMERIC_MIN_DISPLAY_SCALE (NUMERIC_DEFAULT_SCALE + 4) #define NUMERIC_MAX_RESULT_SCALE (NUMERIC_MAX_PRECISION * 2) #define NUMERIC_MIN_RESULT_SCALE (NUMERIC_DEFAULT_PRECISION + 4) -#define NUMERIC_UNPACKED_DATASIZE (NUMERIC_MAX_PRECISION * 2 + 4) - /* ---------- - * Sign values and macros to deal with n_sign_dscale + * Sign values and macros to deal with packing/unpacking n_sign_dscale * ---------- */ #define NUMERIC_SIGN_MASK 0xC000 #define NUMERIC_POS 0x0000 #define NUMERIC_NEG 0x4000 #define NUMERIC_NAN 0xC000 +#define NUMERIC_DSCALE_MASK 0x3FFF #define NUMERIC_SIGN(n) ((n)->n_sign_dscale & NUMERIC_SIGN_MASK) -#define NUMERIC_DSCALE(n) ((n)->n_sign_dscale & ~NUMERIC_SIGN_MASK) +#define NUMERIC_DSCALE(n) ((n)->n_sign_dscale & NUMERIC_DSCALE_MASK) #define NUMERIC_IS_NAN(n) (NUMERIC_SIGN(n) != NUMERIC_POS && \ NUMERIC_SIGN(n) != NUMERIC_NEG) /* ---------- * The Numeric data type stored in the database + * + * NOTE: by convention, values in the packed form have been stripped of + * all leading and trailing zeroes (except there will be a trailing zero + * in the last byte, if the number of digits is odd). In particular, + * if the value is zero, there will be no digits at all! The weight is + * arbitrary in this case, but we normally set it to zero. * ---------- */ typedef struct NumericData @@ -54,7 +64,7 @@ typedef struct NumericData int16 n_weight; /* Weight of 1st digit */ uint16 n_rscale; /* Result scale */ uint16 n_sign_dscale; /* Sign + display scale */ - unsigned char n_data[1]; /* Digit data */ + unsigned char n_data[1]; /* Digit data (2 decimal digits/byte) */ } NumericData; typedef NumericData *Numeric; |