// 重载赋值操作符
smart_ptr& operator= (const smart_ptr& rhs)
{
//给自身赋值也对，因为如果自身赋值，计数器先减1，再加1，并未发生改变
++*count;
decr_count();
pointee = rhs.pointee;
count = rhs.count;
return *this;
}
bool msgpack_unpacker_expand_buffer(msgpack_unpacker* mpac, size_t size)
{
if(mpac->used == mpac->off && get_count(mpac->buffer) == 1
&& !CTX_REFERENCED(mpac)) {
// rewind buffer
mpac->free += mpac->used - COUNTER_SIZE;
mpac->used = COUNTER_SIZE;
mpac->off = COUNTER_SIZE;
if(mpac->free >= size) {
return true;
}
}
if(mpac->off == COUNTER_SIZE) {
char* tmp;
size_t next_size = (mpac->used + mpac->free) * 2; // include COUNTER_SIZE
while(next_size < size + mpac->used) {
size_t tmp_next_size = next_size * 2;
if (tmp_next_size <= next_size) {
next_size = size + mpac->used;
break;
}
next_size = tmp_next_size;
}
tmp = (char*)realloc(mpac->buffer, next_size);
if(tmp == NULL) {
return false;
}
mpac->buffer = tmp;
mpac->free = next_size - mpac->used;
} else {
char* tmp;
size_t next_size = mpac->initial_buffer_size; // include COUNTER_SIZE
size_t not_parsed = mpac->used - mpac->off;
while(next_size < size + not_parsed + COUNTER_SIZE) {
size_t tmp_next_size = next_size * 2;
if (tmp_next_size <= next_size) {
next_size = size + not_parsed + COUNTER_SIZE;
break;
}
next_size = tmp_next_size;
}
tmp = (char*)malloc(next_size);
if(tmp == NULL) {
return false;
}
init_count(tmp);
memcpy(tmp+COUNTER_SIZE, mpac->buffer+mpac->off, not_parsed);
if(CTX_REFERENCED(mpac)) {
if(!msgpack_zone_push_finalizer(mpac->z, decr_count, mpac->buffer)) {
free(tmp);
return false;
}
CTX_REFERENCED(mpac) = false;
} else {
decr_count(mpac->buffer);
}
mpac->buffer = tmp;
mpac->used = not_parsed + COUNTER_SIZE;
mpac->free = next_size - mpac->used;
mpac->off = COUNTER_SIZE;
}
return true;
}
void msgpack_unpacker_destroy(msgpack_unpacker* mpac)
{
msgpack_zone_free(mpac->z);
free(mpac->ctx);
decr_count(mpac->buffer);
}
// 析构，计数减1，减到0时进行垃圾回收，即释放空间
~smart_ptr() { decr_count(); }
