Re: [HACKERS] how can i get the binary format of timestamp?
"[EMAIL PROTECTED]" <[EMAIL PROTECTED]> writes:
> if define HAVE_INT64_TIMESTAMP
> result is: 4E66 E642 0030 C274
> if not define HAVE_INT64_TIMESTAMP
> {
> if define INT64_IS_BUSTED result is: 6972 2142 00DB
> if not define INT64_IS_BUSTED result is: 4221 7269 DB00
> }
I think you got your cases mixed up. In the not-HAVE_INT64_TIMESTAMP
case the value would be a float8 and wouldn't be affected at all by
INT64_IS_BUSTED.
Defining both HAVE_INT64_TIMESTAMP and INT64_IS_BUSTED is not supported.
regards, tom lane
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Re: [HACKERS] how can i get the binary format of timestamp?
Hello,Tom！
Thanks for your answer.
To invoid missing something of the timestamp, i just copy the tm2timestamp
func into my program.(Of course, some other related functions are copied, too),
result is still refusing me.
What i need is: 41A7 7DBA D400 stands for "2006-03-30 18:18:18" ( 41A7
7DBA D400 is got from the Copy to File)
When using tm2timestamp, result is:
if define HAVE_INT64_TIMESTAMP
result is: 4E66 E642 0030 C274
if not define HAVE_INT64_TIMESTAMP
{
if define INT64_IS_BUSTED result is: 6972 2142 00DB
if not define INT64_IS_BUSTED result is: 4221 7269 DB00
}
So, maybe I forget to define something??
/**
* my codes
*
*/
my program is listed:
time_t time = 1143713898;
struct tm* tmField = gmtime(&time);// I know that struct tm dislikes the
struct tm in "time.h"
tmField->tm_year += 1900;
tmField->tm_mon += 1; // So tmFiled is same as pg_tm
int tzp = 8;
char buffer[256];
timestamp timestampField ;
tm2timestamp(tmField,0,&tzp,×tampField);
timestamp_send(timestampField,buffer); // I changed some codes here, to get
the binary format of timestamp
/*/
so ,what switch should i turn on?
=== 2006-04-18 21:47:42 You Wrote：===
>"[EMAIL PROTECTED]" <[EMAIL PROTECTED]> writes:
>> timestamp is defined as int64 or float8, when it is defined as int64, it
>> looks like timeval, first 32 bits for seconds,second 32 bits for usec.
>
>No, it's seconds times 100, not times 2^32.
>
> regards, tom lane
>
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> http://www.postgresql.org/docs/faq
>.
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Re: [HACKERS] how can i get the binary format of timestamp?
"[EMAIL PROTECTED]" <[EMAIL PROTECTED]> writes: > timestamp is defined as int64 or float8, when it is defined as int64, it > looks like timeval, first 32 bits for seconds,second 32 bits for usec. No, it's seconds times 100, not times 2^32. regards, tom lane ---(end of broadcast)--- TIP 3: Have you checked our extensive FAQ? http://www.postgresql.org/docs/faq
[HACKERS] how can i get the binary format of timestamp?
Hello:
I find that the real timestamp format(got from the file which is produced by
copying binary to ) is different from what i find in timestamp_send func.
i do think that the binary format of a timestamp "2006-04-18 11:20:20" should
be "44 2B B0 6A 00 00 00 00" standing for "secs:1143713898, usecs:0" but in
fact it is:"41A7 7DBA D400 "
timestamp is defined as int64 or float8, when it is defined as int64, it looks
like timeval, first 32 bits for seconds,second 32 bits for usec.
and from the timestamp_send func, it just changes the first 32 bits to binary
then combines the next 32 bits
/* codes from timestamp_send
*/
Datum
timestamp_send(PG_FUNCTION_ARGS)
{
Timestamp timestamp = PG_GETARG_TIMESTAMP(0);
StringInfoData buf;
pq_begintypsend(&buf);
#ifdef HAVE_INT64_TIMESTAMP
pq_sendint64(&buf, timestamp);
#else
pq_sendfloat8(&buf, timestamp);
#endif
PG_RETURN_BYTEA_P(pq_endtypsend(&buf));
}
/* codes from pq_sendint64
*/
void
pq_sendint64(StringInfo buf, int64 i)
{
uint32 n32;
/* High order half first, since we're doing MSB-first */
#ifdef INT64_IS_BUSTED
/* don't try a right shift of 32 on a 32-bit word */
n32 = (i < 0) ? -1 : 0;
#else
n32 = (uint32) (i >> 32);
#endif
n32 = htonl(n32);
appendBinaryStringInfo(buf, (char *) &n32, 4);
/* Now the low order half */
n32 = (uint32) i;
n32 = htonl(n32);
appendBinaryStringInfo(buf, (char *) &n32, 4);
}
so i do think that the binary format of a timestamp "2006-04-18 11:20:20"
should be "44 2B B0 6A 00 00 00 00" standing for "secs:1143713898, usecs:0"
but in fact it is:" 41A7 7DBA D400 " , i don't know why.
maybe, i have looked into a wrong func, then which is the right one?
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