pack.c
上传用户:romrleung
上传日期:2022-05-23
资源大小:18897k
文件大小:3k
- /* Copyright (C) 2000-2003 MySQL AB
- This program is free software; you can redistribute it and/or modify
- it under the terms of the GNU General Public License as published by
- the Free Software Foundation; either version 2 of the License, or
- (at your option) any later version.
- This program is distributed in the hope that it will be useful,
- but WITHOUT ANY WARRANTY; without even the implied warranty of
- MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
- GNU General Public License for more details.
- You should have received a copy of the GNU General Public License
- along with this program; if not, write to the Free Software
- Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA */
- #include <my_global.h>
- #include <mysql_com.h>
- #include <mysql.h>
- /* Get the length of next field. Change parameter to point at fieldstart */
- ulong STDCALL net_field_length(uchar **packet)
- {
- reg1 uchar *pos= (uchar *)*packet;
- if (*pos < 251)
- {
- (*packet)++;
- return (ulong) *pos;
- }
- if (*pos == 251)
- {
- (*packet)++;
- return NULL_LENGTH;
- }
- if (*pos == 252)
- {
- (*packet)+=3;
- return (ulong) uint2korr(pos+1);
- }
- if (*pos == 253)
- {
- (*packet)+=4;
- return (ulong) uint3korr(pos+1);
- }
- (*packet)+=9; /* Must be 254 when here */
- return (ulong) uint4korr(pos+1);
- }
- /* The same as above but returns longlong */
- my_ulonglong net_field_length_ll(uchar **packet)
- {
- reg1 uchar *pos= *packet;
- if (*pos < 251)
- {
- (*packet)++;
- return (my_ulonglong) *pos;
- }
- if (*pos == 251)
- {
- (*packet)++;
- return (my_ulonglong) NULL_LENGTH;
- }
- if (*pos == 252)
- {
- (*packet)+=3;
- return (my_ulonglong) uint2korr(pos+1);
- }
- if (*pos == 253)
- {
- (*packet)+=4;
- return (my_ulonglong) uint3korr(pos+1);
- }
- (*packet)+=9; /* Must be 254 when here */
- #ifdef NO_CLIENT_LONGLONG
- return (my_ulonglong) uint4korr(pos+1);
- #else
- return (my_ulonglong) uint8korr(pos+1);
- #endif
- }
- /*
- Store an integer with simple packing into a output package
- SYNOPSIS
- net_store_length()
- pkg Store the packed integer here
- length integers to store
- NOTES
- This is mostly used to store lengths of strings.
- We have to cast the result for the LL() becasue of a bug in Forte CC
- compiler.
- RETURN
- Position in 'pkg' after the packed length
- */
- char *
- net_store_length(char *pkg, ulonglong length)
- {
- uchar *packet=(uchar*) pkg;
- if (length < (ulonglong) LL(251))
- {
- *packet=(uchar) length;
- return (char*) packet+1;
- }
- /* 251 is reserved for NULL */
- if (length < (ulonglong) LL(65536))
- {
- *packet++=252;
- int2store(packet,(uint) length);
- return (char*) packet+2;
- }
- if (length < (ulonglong) LL(16777216))
- {
- *packet++=253;
- int3store(packet,(ulong) length);
- return (char*) packet+3;
- }
- *packet++=254;
- int8store(packet,length);
- return (char*) packet+8;
- }