1 files changed, 235 insertions, 0 deletions
diff --git a/l4basic/l4bds/list.c b/l4basic/l4bds/list.c
new file mode 100644
index 0000000..09ec746
--- /dev/null
+++ b/l4basic/l4bds/list.c
@@ -0,0 +1,235 @@
+#include <stdlib.h>
+#include <string.h>
+#include <l4bds.h>
+
+L4LL* l4ll_create(void){
+	L4LL* newlist = (L4LL*)malloc(sizeof(L4LL));
+	if(newlist == NULL){
+		return NULL;
+	}
+	newlist->list_first = NULL;
+	newlist->list_last = NULL;
+	newlist->list_len = 0;
+	return newlist;
+}
+
+void l4ll_free(L4LL* oldlist){
+	if(oldlist->list_len <= 0){
+		free(oldlist);
+		return;
+	}
+	L4LLNODE* i;
+	L4LLNODE* next;
+	for(i=oldlist->list_first; i!=NULL; i=next){
+		next = i->node_next;
+		if(i->node_data_size){ /* 只要資料大小不為零，就還要釋放資料區 */
+			free(i->node_data);
+		}
+		free(i);
+	}
+	free(oldlist);
+}
+
+static L4LLNODE* 
+l4ll_initfirst(L4LL* list, const void* data, int size){
+	/* 插入第一個資料，如果 list 不是空的就別用！
+	 * 否則會造成資料結構混亂和 memory leak */
+	L4LLNODE* node = (L4LLNODE*)malloc(sizeof(L4LLNODE));
+	if(node == NULL){
+		return NULL;
+	}
+	void* newdata;
+   	if(size != 0){
+		newdata = malloc(size);
+		if(newdata == NULL){
+			free(node);
+			return NULL;
+		}
+		memcpy(newdata, data, size);
+	}
+	list->list_first = node;
+	list->list_last = node;
+	list->list_len = 1;
+	node->node_prev = NULL;
+	node->node_next = NULL;
+	node->node_data = (size != 0) ? newdata : NULL;
+	node->node_data_size = size;
+	return node;
+}
+
+L4LLNODE* l4ll_insert_prev(L4LL* list, L4LLNODE* node, 
+		const void* data, int size){
+	/* list 送 NULL 來的我不理它，就自己去 segfault 吧
+	 * node 送 NULL 來只能在 list 是空的時候用 */
+	if(list->list_len == 0){
+		return l4ll_initfirst(list, data, size);
+	}
+	L4LLNODE* newnode = (L4LLNODE*)malloc(sizeof(L4LLNODE));
+	if(newnode == NULL){
+		return NULL;
+	}
+	void* newdata;
+	if(size != 0){
+		newdata = malloc(size);
+		if(newdata == NULL){
+			free(newnode);
+			return NULL;
+		}
+		memcpy(newdata, data, size);
+	}
+	list->list_len++;
+	if(list->list_first == node){ /* 如果是第一個，那要修改 list_first */
+		list->list_first = newnode;
+	}
+	L4LLNODE* oldprev = node->node_prev;
+	node->node_prev = newnode;
+	newnode->node_next = node;
+	newnode->node_prev = oldprev;
+	if(oldprev != NULL){
+		oldprev->node_next = newnode;
+	}
+	newnode->node_data = (size != 0) ? newdata : NULL;
+	newnode->node_data_size = size;
+	return newnode;
+}
+
+L4LLNODE* l4ll_insert_next(L4LL* list, L4LLNODE* node, 
+		const void* data, int size){
+	/* 基本上同 l4ll_insert_prev */
+	if(list->list_len == 0){
+		return l4ll_initfirst(list, data, size);
+	}
+	L4LLNODE* newnode = (L4LLNODE*)malloc(sizeof(L4LLNODE));
+	if(newnode == NULL){
+		return NULL;
+	}
+	void* newdata;
+	if(size != 0){
+		newdata = malloc(size);
+		if(newdata == NULL){
+			free(newnode);
+			return NULL;
+		}
+		memcpy(newdata, data, size);
+	}
+	list->list_len++;
+	if(list->list_last == node){
+		list->list_last = newnode;
+	}
+	L4LLNODE* oldnext = node->node_next;
+	node->node_next = newnode;
+	newnode->node_prev = node;
+	newnode->node_next = oldnext;
+	if(oldnext != NULL){
+		oldnext->node_prev = newnode;
+	}
+	newnode->node_data = (size != 0) ? newdata : NULL;
+	newnode->node_data_size = size;
+	return newnode;
+}
+
+void l4ll_remove(L4LL* list, L4LLNODE* node){
+	/* 不要在 node 傳 NULL，這一點意義也沒有且我不知道會發生什麼事 */
+	if(list->list_first == node){
+		list->list_first = node->node_next;
+	}
+	if(list->list_last == node){
+		list->list_last = node->node_prev;
+	}
+	list->list_len--; /* 不考慮長度為零的情況，空白是想要刪什麼？ */
+	L4LLNODE* oldnext = node->node_next;
+	L4LLNODE* oldprev = node->node_prev;
+	if(node->node_data_size != 0){
+		free(node->node_data);
+	}
+	free(node);
+	if(oldnext != NULL){
+		oldnext->node_prev = oldprev;
+	}
+	if(oldprev != NULL){
+		oldprev->node_next = oldnext;
+	}
+}
+
+L4LLNODE* l4ll_goto(L4LLNODE* node, int count){
+	int i;
+	if(count == 0){
+		return node;
+	}else if(count > 0){
+		for(i=1; i<=count; i++){
+			node = node->node_next;
+			if(node == NULL){
+				return NULL;
+			}
+		}
+	}else{
+		count = -count;
+		for(i=1; i<=count; i++){
+			node = node->node_prev;
+			if(node == NULL){
+				return NULL;
+			}
+		}
+	}
+	return node;
+}
+
+#if 0
+int l4ll_pushback(L4LL* list, void* data, int size){
+	L4LLNODE* cur_save = list->list_current; /* 等一下要把現在位置搬回去 */
+	list->list_current = list->list_last;
+	int result = l4ll_insnext(list, data, size);
+	if(result == 0){ /* 成功 */
+		if(cur_save != NULL){ /* 原先的現在位置若為空就無意義了 */
+			list->list_current = cur_save;
+		}
+	}else{ /* 失敗 */
+		list->list_current = cur_save;
+	}
+	return result;
+}
+
+
+int l4ll_pushfront(L4LL*, void*){ /* 取自 l4ll_pushback */
+	L4LLNODE* cur_save = list->list_current; 
+	list->list_current = list->list_front;
+	int result = l4ll_insprev(list, data, size);
+	if(result == 0){
+		if(cur_save != NULL){ 
+			list->list_current = cur_save;
+		}
+	}else{ 
+		list->list_current = cur_save;
+	}
+	return result;
+}
+
+int l4ll_popback(L4LL*){
+	L4LLNODE* cur_save = list->list_current;
+	L4LLNODE* last_save = list->list_last
+	list->list_current = last_save;
+	int result = l4ll_remove(list, L4LL_PREV);
+	if(result == 0){ 
+		if(cur_save != NULL && ){ 
+			list->list_current = cur_save;
+		}
+	}else{ 
+		list->list_current = cur_save;
+	}
+	return result;
+}
+
+int l4ll_popfront(L4LL*){
+	L4LLNODE* cur_save = list->list_current;
+	list->list_current = list->list_first;
+	int result = l4ll_remove(list, L4LL_NEXT);
+	if(result == 0){ 
+		if(cur_save != NULL){ 
+			list->list_current = cur_save;
+		}
+	}else{ 
+		list->list_current = cur_save;
+	}
+	return result;
+}
+#endif