diff options
Diffstat (limited to 'src/timezone/tzfile.h')
| -rw-r--r-- | src/timezone/tzfile.h | 40 |
1 files changed, 27 insertions, 13 deletions
diff --git a/src/timezone/tzfile.h b/src/timezone/tzfile.h index 0f447a543dc..a358cad5210 100644 --- a/src/timezone/tzfile.h +++ b/src/timezone/tzfile.h @@ -3,10 +3,10 @@ /* * This file is in the public domain, so clarified as of - * 1996-06-05 by Arthur David Olson ([email protected]). + * 1996-06-05 by Arthur David Olson. * * IDENTIFICATION - * $PostgreSQL: pgsql/src/timezone/tzfile.h,v 1.6 2005/10/15 02:49:51 momjian Exp $ + * $PostgreSQL: pgsql/src/timezone/tzfile.h,v 1.7 2008/02/16 21:16:04 tgl Exp $ */ /* @@ -33,7 +33,8 @@ struct tzhead { char tzh_magic[4]; /* TZ_MAGIC */ - char tzh_reserved[16]; /* reserved for future use */ + char tzh_version[1]; /* '\0' or '2' as of 2005 */ + char tzh_reserved[15]; /* reserved--must be zero */ char tzh_ttisgmtcnt[4]; /* coded number of trans. time flags */ char tzh_ttisstdcnt[4]; /* coded number of trans. time flags */ char tzh_leapcnt[4]; /* coded number of leap seconds */ @@ -69,17 +70,21 @@ struct tzhead */ /* - * In the current implementation, "tzset()" refuses to deal with files that - * exceed any of the limits below. + * If tzh_version is '2' or greater, the above is followed by a second instance + * of tzhead and a second instance of the data in which each coded transition + * time uses 8 rather than 4 chars, + * then a POSIX-TZ-environment-variable-style string for use in handling + * instants after the last transition time stored in the file + * (with nothing between the newlines if there is no POSIX representation for + * such instants). */ /* - * The TZ_MAX_TIMES value below is enough to handle a bit more than a - * year's worth of solar time (corrected daily to the nearest second) or - * 138 years of Pacific Presidential Election time - * (where there are three time zone transitions every fourth year). + * In the current implementation, "tzset()" refuses to deal with files that + * exceed any of the limits below. */ -#define TZ_MAX_TIMES 370 + +#define TZ_MAX_TIMES 1200 #define TZ_MAX_TYPES 256 /* Limited by what (unsigned char)'s can hold */ @@ -124,11 +129,20 @@ struct tzhead #define EPOCH_YEAR 1970 #define EPOCH_WDAY TM_THURSDAY +#define isleap(y) (((y) % 4) == 0 && (((y) % 100) != 0 || ((y) % 400) == 0)) + /* - * Accurate only for the past couple of centuries; - * that will probably do. + * Since everything in isleap is modulo 400 (or a factor of 400), we know that + * isleap(y) == isleap(y % 400) + * and so + * isleap(a + b) == isleap((a + b) % 400) + * or + * isleap(a + b) == isleap(a % 400 + b % 400) + * This is true even if % means modulo rather than Fortran remainder + * (which is allowed by C89 but not C99). + * We use this to avoid addition overflow problems. */ -#define isleap(y) (((y) % 4) == 0 && (((y) % 100) != 0 || ((y) % 400) == 0)) +#define isleap_sum(a, b) isleap((a) % 400 + (b) % 400) #endif /* !defined TZFILE_H */ |