diff options
Diffstat (limited to 'mariadb-connector-c-v_2.3.7/libmariadb/my_alloc.c')
| -rw-r--r-- | mariadb-connector-c-v_2.3.7/libmariadb/my_alloc.c | 169 |
1 files changed, 169 insertions, 0 deletions
diff --git a/mariadb-connector-c-v_2.3.7/libmariadb/my_alloc.c b/mariadb-connector-c-v_2.3.7/libmariadb/my_alloc.c new file mode 100644 index 0000000..8d31d5d --- /dev/null +++ b/mariadb-connector-c-v_2.3.7/libmariadb/my_alloc.c @@ -0,0 +1,169 @@ +/* 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., 51 Franklin Street, Fifth Floor, Boston, + MA 02111-1301, USA */ + +/* Routines to handle mallocing of results which will be freed the same time */ + +#include <my_global.h> +#include <my_sys.h> +#include <m_string.h> + +void init_alloc_root(MEM_ROOT *mem_root, size_t block_size, size_t pre_alloc_size) +{ + mem_root->free= mem_root->used= mem_root->pre_alloc= 0; + mem_root->min_malloc=32; + mem_root->block_size= (block_size-MALLOC_OVERHEAD-sizeof(USED_MEM)+8); + mem_root->error_handler=0; + mem_root->block_num= 4; + mem_root->first_block_usage= 0; +#if !(defined(HAVE_purify) && defined(EXTRA_DEBUG)) + if (pre_alloc_size) + { + if ((mem_root->free = mem_root->pre_alloc= + (USED_MEM*) my_malloc(pre_alloc_size+ ALIGN_SIZE(sizeof(USED_MEM)), + MYF(0)))) + { + mem_root->free->size=pre_alloc_size+ALIGN_SIZE(sizeof(USED_MEM)); + mem_root->free->left=pre_alloc_size; + mem_root->free->next=0; + } + } +#endif +} + +gptr alloc_root(MEM_ROOT *mem_root, size_t Size) +{ +#if defined(HAVE_purify) && defined(EXTRA_DEBUG) + reg1 USED_MEM *next; + Size+=ALIGN_SIZE(sizeof(USED_MEM)); + + if (!(next = (USED_MEM*) my_malloc(Size,MYF(MY_WME)))) + { + if (mem_root->error_handler) + (*mem_root->error_handler)(); + return((gptr) 0); /* purecov: inspected */ + } + next->next=mem_root->used; + mem_root->used=next; + return (gptr) (((char*) next)+ALIGN_SIZE(sizeof(USED_MEM))); +#else + size_t get_size,max_left; + gptr point; + reg1 USED_MEM *next= 0; + reg2 USED_MEM **prev; + + Size= ALIGN_SIZE(Size); + max_left=0; + + if ((*(prev= &mem_root->free))) + { + if ((*prev)->left < Size && + mem_root->first_block_usage++ >= 16 && + (*prev)->left < 4096) + { + next= *prev; + *prev= next->next; + next->next= mem_root->used; + mem_root->used= next; + mem_root->first_block_usage= 0; + } + for (next= *prev; next && next->left < Size; next= next->next) + prev= &next->next; + } + + if (! next) + { /* Time to alloc new block */ + get_size= MAX(Size+ALIGN_SIZE(sizeof(USED_MEM)), + (mem_root->block_size & ~1) * (mem_root->block_num >> 2)); + + if (!(next = (USED_MEM*) my_malloc(get_size,MYF(MY_WME)))) + { + if (mem_root->error_handler) + (*mem_root->error_handler)(); + return((gptr) 0); /* purecov: inspected */ + } + mem_root->block_num++; + next->next= *prev; + next->size= get_size; + next->left= get_size-ALIGN_SIZE(sizeof(USED_MEM)); + *prev=next; + } + point= (gptr) ((char*) next+ (next->size-next->left)); + if ((next->left-= Size) < mem_root->min_malloc) + { /* Full block */ + *prev=next->next; /* Remove block from list */ + next->next=mem_root->used; + mem_root->used=next; + mem_root->first_block_usage= 0; + } + return(point); +#endif +} + + /* deallocate everything used by alloc_root */ + +void free_root(MEM_ROOT *root, myf MyFlags) +{ + reg1 USED_MEM *next,*old; + DBUG_ENTER("free_root"); + + if (!root) + DBUG_VOID_RETURN; /* purecov: inspected */ + if (!(MyFlags & MY_KEEP_PREALLOC)) + root->pre_alloc=0; + + for ( next=root->used; next ;) + { + old=next; next= next->next ; + if (old != root->pre_alloc) + my_free(old); + } + for (next= root->free ; next ; ) + { + old=next; next= next->next ; + if (old != root->pre_alloc) + my_free(old); + } + root->used=root->free=0; + if (root->pre_alloc) + { + root->free=root->pre_alloc; + root->free->left=root->pre_alloc->size-ALIGN_SIZE(sizeof(USED_MEM)); + root->free->next=0; + } + root->block_num= 4; + root->first_block_usage= 0; + DBUG_VOID_RETURN; +} + + +char *strdup_root(MEM_ROOT *root,const char *str) +{ + size_t len= strlen(str)+1; + char *pos; + if ((pos=alloc_root(root,len))) + memcpy(pos,str,len); + return pos; +} + + +char *memdup_root(MEM_ROOT *root, const char *str, size_t len) +{ + char *pos; + if ((pos=alloc_root(root,len))) + memcpy(pos,str,len); + return pos; +} |