// local ret = driver.readline(s.buffer, buffer_pool, sep)
// return msg/true/nil
// buffer_pool 缓冲池，如果传入nil 返回是否存在分隔符，如果传入table，返回读入的缓冲区数据
// sep 分隔符 比如\n
static int
lreadline(lua_State *L) {
struct socket_buffer * sb = lua_touserdata(L, 1);
if (sb == NULL) {
return luaL_error(L, "Need buffer object at param 1");
}
// only check
// 如果第二个参数是lua table，check为false，否则check为true
bool check = !lua_istable(L, 2);
size_t seplen = 0;
// 获取第三个参数值，分隔符字符串，同时获取其长度
const char *sep = luaL_checklstring(L,3,&seplen);
int i;
struct buffer_node *current = sb->head;
if (current == NULL)
return 0;
int from = sb->offset;
// 当前缓冲区节点可读数据长度
int bytes = current->sz - from;
for (i=0;i<=sb->size - (int)seplen;i++) {
if (check_sep(current, from, sep, seplen)) {
// 如果有分隔符
if (check) {
// 如果没有传入buffer_pool参数，则返回true
/*
比如 socket.lua
if driver.readline(s.buffer, nil, rr) then
s.read_required = nil
wakeup(s)
end
*/
lua_pushboolean(L,true);
} else {
// 读入缓冲区数据并压栈作为lua返回值
pop_lstring(L, sb, i+seplen, seplen);
sb->size -= i+seplen;
}
return 1;
}
// 如果没有分隔符，移动一个字符继续检索
++from;
--bytes;
if (bytes == 0) {
// 读完一个缓冲区节点，换下一个缓冲区节点
current = current->next;
from = 0;
if (current == NULL)
// 下一个为空，跳出循环
break;
bytes = current->sz;
}
}
// 如果没有分隔符，没有返回参数
return 0;
}
/*
userdata send_buffer
table pool , nil for check
string sep
*/
static int
lreadline(lua_State *L) {
struct socket_buffer * sb = lua_touserdata(L, 1);
if (sb == NULL) {
return luaL_error(L, "Need buffer object at param 1");
}
// only check
bool check = !lua_istable(L, 2);
size_t seplen = 0;
const char *sep = luaL_checklstring(L,3,&seplen);
int i;
struct buffer_node *current = sb->head;
if (current == NULL)
return 0;
int from = sb->offset;
int bytes = current->sz - from;
for (i=0;i<=sb->size - (int)seplen;i++) {
if (check_sep(current, from, sep, seplen)) {
if (check) {
lua_pushboolean(L,true);
} else {
pop_lstring(L, sb, i+seplen, seplen);
sb->size -= i+seplen;
}
return 1;
}
++from;
--bytes;
if (bytes == 0) {
current = current->next;
from = 0;
if (current == NULL)
break;
bytes = current->sz;
}
}
return 0;
}
