string.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 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 */
- /*
- Code for handling strings with can grow dynamicly.
- Copyright Monty Program KB.
- By monty.
- */
- #include "mysys_priv.h"
- #include <m_string.h>
- my_bool init_dynamic_string(DYNAMIC_STRING *str, const char *init_str,
- uint init_alloc, uint alloc_increment)
- {
- uint length;
- DBUG_ENTER("init_dynamic_string");
- if (!alloc_increment)
- alloc_increment=128;
- length=1;
- if (init_str && (length= (uint) strlen(init_str)+1) < init_alloc)
- init_alloc=((length+alloc_increment-1)/alloc_increment)*alloc_increment;
- if (!init_alloc)
- init_alloc=alloc_increment;
- if (!(str->str=(char*) my_malloc(init_alloc,MYF(MY_WME))))
- DBUG_RETURN(TRUE);
- str->length=length-1;
- if (init_str)
- memcpy(str->str,init_str,length);
- str->max_length=init_alloc;
- str->alloc_increment=alloc_increment;
- DBUG_RETURN(FALSE);
- }
- my_bool dynstr_set(DYNAMIC_STRING *str, const char *init_str)
- {
- uint length=0;
- DBUG_ENTER("dynstr_set");
- if (init_str && (length= (uint) strlen(init_str)+1) > str->max_length)
- {
- str->max_length=((length+str->alloc_increment-1)/str->alloc_increment)*
- str->alloc_increment;
- if (!str->max_length)
- str->max_length=str->alloc_increment;
- if (!(str->str=(char*) my_realloc(str->str,str->max_length,MYF(MY_WME))))
- DBUG_RETURN(TRUE);
- }
- if (init_str)
- {
- str->length=length-1;
- memcpy(str->str,init_str,length);
- }
- else
- str->length=0;
- DBUG_RETURN(FALSE);
- }
- my_bool dynstr_realloc(DYNAMIC_STRING *str, ulong additional_size)
- {
- DBUG_ENTER("dynstr_realloc");
- if (!additional_size) DBUG_RETURN(FALSE);
- if (str->length + additional_size > str->max_length)
- {
- str->max_length=((str->length + additional_size+str->alloc_increment-1)/
- str->alloc_increment)*str->alloc_increment;
- if (!(str->str=(char*) my_realloc(str->str,str->max_length,MYF(MY_WME))))
- DBUG_RETURN(TRUE);
- }
- DBUG_RETURN(FALSE);
- }
- my_bool dynstr_append(DYNAMIC_STRING *str, const char *append)
- {
- return dynstr_append_mem(str,append,strlen(append));
- }
- my_bool dynstr_append_mem(DYNAMIC_STRING *str, const char *append,
- uint length)
- {
- char *new_ptr;
- if (str->length+length >= str->max_length)
- {
- uint new_length=(str->length+length+str->alloc_increment)/
- str->alloc_increment;
- new_length*=str->alloc_increment;
- if (!(new_ptr=(char*) my_realloc(str->str,new_length,MYF(MY_WME))))
- return TRUE;
- str->str=new_ptr;
- str->max_length=new_length;
- }
- memcpy(str->str + str->length,append,length);
- str->length+=length;
- str->str[str->length]=0; /* Safety for C programs */
- return FALSE;
- }
- void dynstr_free(DYNAMIC_STRING *str)
- {
- if (str->str)
- {
- my_free(str->str,MYF(MY_WME));
- str->str=0;
- }
- }