Hi,
It seems some changes occured in network protocol between 7.3 and 7.4.
In my simple libray above libpq, I used this call to extract float8 with
a binary cursor (on x86) :
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memcpy(&float8, PQgetvalue(pg_res, tup_num, field_num), PQfsize(pg_res, field_num));
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Now with PostgreSQL 7.4, I replaced this memcpy by theses lines :
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union {double d; int64_t i64;
} swap;
uint32_t tab_uint32[2];
/* Read two uint32 */
memcpy(tab_uint32, PQgetvalue(pg_res, tup_num, field_num), 8);
/* Swap MSB -> LSB */
tab_uint32[0] = ntohl(tab_uint32[0]);
tab_uint32[1] = ntohl(tab_uint32[1]);
/* Fusion */
swap.i64 = tab_uint32[0];
swap.i64 <<= 32;
swap.i64 |= tab_uint32[1];
/* Cast */
return swap.d;
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Is it the right method to extract binary data ? Don't exist a easiest
method ?
Thank you.
Stephane
