diff options
Diffstat (limited to 'doc')
| -rw-r--r-- | doc/src/sgml/libpq.sgml | 23 |
1 files changed, 15 insertions, 8 deletions
diff --git a/doc/src/sgml/libpq.sgml b/doc/src/sgml/libpq.sgml index 54dd71e03bf..bce5b80d724 100644 --- a/doc/src/sgml/libpq.sgml +++ b/doc/src/sgml/libpq.sgml @@ -4687,22 +4687,29 @@ typedef struct parameters to be passed to the function; they must match the declared function argument list. When the <parameter>isint</> field of a parameter structure is true, the <parameter>u.integer</> value is sent - to the server as an integer of the indicated length (this must be 1, - 2, or 4 bytes); proper byte-swapping occurs. When <parameter>isint</> + to the server as an integer of the indicated length (this must be + 2 or 4 bytes); proper byte-swapping occurs. When <parameter>isint</> is false, the indicated number of bytes at <parameter>*u.ptr</> are sent with no processing; the data must be in the format expected by the server for binary transmission of the function's argument data - type. <parameter>result_buf</parameter> is the buffer in which to - place the return value. The caller must have allocated sufficient + type. (The declaration of <parameter>u.ptr</> as being of + type <type>int *</> is historical; it would be better to consider + it <type>void *</>.) + <parameter>result_buf</parameter> points to the buffer in which to place + the function's return value. The caller must have allocated sufficient space to store the return value. (There is no check!) The actual result - length will be returned in the integer pointed to by - <parameter>result_len</parameter>. If a 1, 2, or 4-byte integer result + length in bytes will be returned in the integer pointed to by + <parameter>result_len</parameter>. If a 2- or 4-byte integer result is expected, set <parameter>result_is_int</parameter> to 1, otherwise set it to 0. Setting <parameter>result_is_int</parameter> to 1 causes <application>libpq</> to byte-swap the value if necessary, so that it - is delivered as a proper <type>int</type> value for the client machine. + is delivered as a proper <type>int</type> value for the client machine; + note that a 4-byte integer is delivered into <parameter>*result_buf</> + for either allowed result size. When <parameter>result_is_int</> is 0, the binary-format byte string - sent by the server is returned unmodified. + sent by the server is returned unmodified. (In this case it's better + to consider <parameter>result_buf</parameter> as being of + type <type>void *</>.) </para> <para> |