diff options
Diffstat (limited to 'mysys/array.c')
| -rw-r--r-- | mysys/array.c | 177 |
1 files changed, 177 insertions, 0 deletions
diff --git a/mysys/array.c b/mysys/array.c new file mode 100644 index 00000000000..17e5ded322b --- /dev/null +++ b/mysys/array.c @@ -0,0 +1,177 @@ +/* Copyright (C) 2000 MySQL AB & MySQL Finland AB & TCX DataKonsult AB + + This library is free software; you can redistribute it and/or + modify it under the terms of the GNU Library General Public + License as published by the Free Software Foundation; either + version 2 of the License, or (at your option) any later version. + + This library 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 + Library General Public License for more details. + + You should have received a copy of the GNU Library General Public + License along with this library; if not, write to the Free + Software Foundation, Inc., 59 Temple Place - Suite 330, Boston, + MA 02111-1307, USA */ + +/* Handling of arrays that can grow dynamicly. */ + +#if defined(WIN32) || defined(__WIN__) +#undef SAFEMALLOC /* Problems with threads */ +#endif + +#include "mysys_priv.h" +#include "m_string.h" + +/* + Initiate array and alloc space for init_alloc elements. Array is usable + even if space allocation failed +*/ + +my_bool init_dynamic_array(DYNAMIC_ARRAY *array, uint element_size, + uint init_alloc, uint alloc_increment) +{ + DBUG_ENTER("init_dynamic_array"); + if (!alloc_increment) + { + alloc_increment=max((8192-MALLOC_OVERHEAD)/element_size,16); + if (init_alloc > 8 && alloc_increment > init_alloc * 2) + alloc_increment=init_alloc*2; + } + + if (!init_alloc) + init_alloc=alloc_increment; + array->elements=0; + array->max_element=init_alloc; + array->alloc_increment=alloc_increment; + array->size_of_element=element_size; + if (!(array->buffer=(char*) my_malloc(element_size*init_alloc,MYF(MY_WME)))) + { + array->max_element=0; + DBUG_RETURN(TRUE); + } + DBUG_RETURN(FALSE); +} + + +my_bool insert_dynamic(DYNAMIC_ARRAY *array, gptr element) +{ + gptr buffer; + if (array->elements == array->max_element) + { /* Call only when nessesary */ + if (!(buffer=alloc_dynamic(array))) + return TRUE; + } + else + { + buffer=array->buffer+(array->elements * array->size_of_element); + array->elements++; + } + memcpy(buffer,element,(size_t) array->size_of_element); + return FALSE; +} + + + /* Alloc room for one element */ + +byte *alloc_dynamic(DYNAMIC_ARRAY *array) +{ + if (array->elements == array->max_element) + { + char *new_ptr; + if (!(new_ptr=(char*) my_realloc(array->buffer,(array->max_element+ + array->alloc_increment)* + array->size_of_element, + MYF(MY_WME | MY_ALLOW_ZERO_PTR)))) + return 0; + array->buffer=new_ptr; + array->max_element+=array->alloc_increment; + } + return array->buffer+(array->elements++ * array->size_of_element); +} + + + /* remove last element from array and return it */ + +byte *pop_dynamic(DYNAMIC_ARRAY *array) +{ + if (array->elements) + return array->buffer+(--array->elements * array->size_of_element); + return 0; +} + + +my_bool set_dynamic(DYNAMIC_ARRAY *array, gptr element, uint idx) +{ + if (idx >= array->elements) + { + if (idx >= array->max_element) + { + uint size; + char *new_ptr; + size=(idx+array->alloc_increment)/array->alloc_increment; + size*= array->alloc_increment; + if (!(new_ptr=(char*) my_realloc(array->buffer,size* + array->size_of_element, + MYF(MY_WME | MY_ALLOW_ZERO_PTR)))) + return TRUE; + array->buffer=new_ptr; + array->max_element=size; + } + bzero((gptr) (array->buffer+array->elements*array->size_of_element), + (idx - array->elements)*array->size_of_element); + array->elements=idx+1; + } + memcpy(array->buffer+(idx * array->size_of_element),element, + (size_t) array->size_of_element); + return FALSE; +} + + +void get_dynamic(DYNAMIC_ARRAY *array, gptr element, uint idx) +{ + if (idx >= array->elements) + { + DBUG_PRINT("warning",("To big array idx: %d, array size is %d", + idx,array->elements)); + bzero(element,array->size_of_element); + return; + } + memcpy(element,array->buffer+idx*array->size_of_element, + (size_t) array->size_of_element); +} + + +void delete_dynamic(DYNAMIC_ARRAY *array) +{ + if (array->buffer) + { + my_free(array->buffer,MYF(MY_WME)); + array->buffer=0; + array->elements=array->max_element=0; + } +} + + +void delete_dynamic_element(DYNAMIC_ARRAY *array, uint idx) +{ + char *ptr=array->buffer+array->size_of_element*idx; + array->elements--; + memmove(ptr,ptr+array->size_of_element, + (array->elements-idx)*array->size_of_element); +} + + +void freeze_size(DYNAMIC_ARRAY *array) +{ + uint elements=max(array->elements,1); + + if (array->buffer && array->max_element != elements) + { + array->buffer=(char*) my_realloc(array->buffer, + elements*array->size_of_element, + MYF(MY_WME)); + array->max_element=elements; + } +} |