/* Insert an integer in the intset */
intset *intsetAdd(intset *is, int64_t value, uint8_t *success) {
uint8_t valenc = _intsetValueEncoding(value);
uint32_t pos;
if (success) *success = 1;
/* Upgrade encoding if necessary. If we need to upgrade, we know that
* this value should be either appended (if > 0) or prepended (if < 0),
* because it lies outside the range of existing values. */
if (valenc > is->encoding) {
/* This always succeeds, so we don't need to curry *success. */
return intsetUpgradeAndAdd(is,value);
} else {
/* Abort if the value is already present in the set.
* This call will populate "pos" with the right position to insert
* the value when it cannot be found. */
if (intsetSearch(is,value,&pos)) {
if (success) *success = 0;
return is;
}
is = intsetResize(is,is->length+1);
if (pos < is->length) intsetMoveTail(is,pos,pos+1);
}
_intsetSet(is,pos,value);
is->length++;
return is;
}
/* Insert an integer in the intset */
intset *intsetAdd(intset *is, int64_t value, uint8_t *success) {
uint8_t valenc = _intsetValueEncoding(value);
uint32_t pos;
if (success) *success = 1;
/* Upgrade encoding if necessary. If we need to upgrade, we know that
* this value should be either appended (if > 0) or prepended (if < 0),
* because it lies outside the range of existing values. */
// 需要插入整数的所需内存超出了原有集合整数的范围，即内存类型不同，
// 则升级整数类型
if (valenc > intrev32ifbe(is->encoding)) {
/* This always succeeds, so we don't need to curry *success. */
return intsetUpgradeAndAdd(is,value);
// 正常，分配内存，插入
} else {
// intset 内部不允许重复
/* Abort if the value is already present in the set.
* This call will populate "pos" with the right position to insert
* the value when it cannot be found. */
if (intsetSearch(is,value,&pos)) {
if (success) *success = 0;
return is;
}
// realloc
is = intsetResize(is,intrev32ifbe(is->length)+1);
// 迁移内存，腾出空间给新的数据。intsetMoveTail() 完成内存迁移工作
if (pos < intrev32ifbe(is->length)) intsetMoveTail(is,pos,pos+1);
}
// 在腾出的空间中设置新的数据
_intsetSet(is,pos,value);
// 更新 intset size
is->length = intrev32ifbe(intrev32ifbe(is->length)+1);
return is;
}
/*
* 将 value 添加到集合中
*
* 如果元素已经存在， *success 被设置为 0 ，
* 如果元素添加成功， *success 被设置为 1 。
*
* T = O(n)
*/
intset *intsetAdd(intset *is, int64_t value, uint8_t *success) {
uint8_t valenc = _intsetValueEncoding(value);
uint32_t pos;
if (success) *success = 1;
/* Upgrade encoding if necessary. If we need to upgrade, we know that
* this value should be either appended (if > 0) or prepended (if < 0),
* because it lies outside the range of existing values. */
// 如果有需要，进行升级并插入新值
if (valenc > intrev32ifbe(is->encoding)) {
/* This always succeeds, so we don't need to curry *success. */
return intsetUpgradeAndAdd(is,value);
} else {
/* Abort if the value is already present in the set.
* This call will populate "pos" with the right position to insert
* the value when it cannot be found. */
// 如果值已经存在，那么直接返回
// 如果不存在，那么设置 *pos 设置为新元素添加的位置
if (intsetSearch(is,value,&pos)) {
if (success) *success = 0;
return is;
}
// 扩张 is ，准备添加新元素
is = intsetResize(is,intrev32ifbe(is->length)+1);
// 如果 pos 不是数组中最后一个位置，
// 那么对数组中的原有元素进行移动
if (pos < intrev32ifbe(is->length)) intsetMoveTail(is,pos,pos+1);
}
// 添加新元素
_intsetSet(is,pos,value);
// 更新元素数量
is->length = intrev32ifbe(intrev32ifbe(is->length)+1);
return is;
}
//将value插入到整数集中
intset *intsetAdd(intset *is, int64_t value, uint8_t *success) {
uint8_t valenc = _intsetValueEncoding(value);
uint32_t pos;
if (success) *success = 1;
/* Upgrade encoding if necessary. If we need to upgrade, we know that
* this value should be either appended (if > 0) or prepended (if < 0),
* because it lies outside the range of existing values. */
if (valenc > intrev32ifbe(is->encoding)) {
//如果表示value所需编码比现整数集的编码要大，升级整数集并将元素插入
/* This always succeeds, so we don't need to curry *success. */
return intsetUpgradeAndAdd(is,value);
} else {
/* Abort if the value is already present in the set.
* This call will populate "pos" with the right position to insert
* the value when it cannot be found. */
//调用intsetSearch查找元素，如果已经存在则返回0
if (intsetSearch(is,value,&pos)) {
if (success) *success = 0;
return is;
}
//扩大内存空间
is = intsetResize(is,intrev32ifbe(is->length)+1);
//将原来从pos到末尾的元素都向后移动一位
if (pos < intrev32ifbe(is->length)) intsetMoveTail(is,pos,pos+1);
}
//将value设到pos位上
_intsetSet(is,pos,value);
//更新元素个数
is->length = intrev32ifbe(intrev32ifbe(is->length)+1);
return is;
}
/* Insert an integer in the intset
*
* 尝试将元素value添加到整数集合中。
*
* *success的值指示添加是否成功：
* -如果添加成功，那么将*success的值设为1。
* -因为元素已存在而造成添加失败时，将*success的值设为0。
*
* T = O(N)
*/
intset *intsetAdd(intset *is, int64_t value, uint8_t *success) {
// 计算编码value所需的长度
uint8_t valenc = _intsetValueEncoding(value);
uint32_t pos;
// 默认设置插入为成功
if (success) *success = 1;
/* Upgrade encoding if necessary. If we need to upgrade, we know that
* this value should be either appended (if > 0) or prepended (if < 0),
* because it lies outside the range of existing values. */
// 如果value的编码比整数集合现在的编码要大
// 那么表示value必然可以添加到整数集合中
// 并且整数集合需要对自身进行升级，才能满足value所需的编码
if (valenc > intrev32ifbe(is->encoding)) {
/* This always succeeds, so we don't need to curry *success. */
// T = O(N)
return intsetUpgradeAndAdd(is,value);
} else {
// 运行到这里，表示整数集合现有的编码方式适用于value
/* Abort if the value is already present in the set.
* This call will populate "pos" with the right position to insert
* the value when it cannot be found. */
// 在整数集合中查找value，看他是否存在：
// -如果存在，那么将*success设置为0，并返回未经改动的整数集合
// -如果不存在，那么可以插入value的位置将被保存到pos指针中
// 等待后续程序使用
if (intsetSearch(is,value,&pos)) {
if (success) *success = 0;
return is;
}
// 运行到这里，表示value不存在于集合中
// 程序需要将value添加到整数集合中
// 为value在集合中分配空间
is = intsetResize(is,intrev32ifbe(is->length)+1);
// 如果新元素不是被添加到底层数组的末端
// 那么需要对现有元素的数据进行移动，空出pos上的位置，用于设置新值
// 举个例子
// 如果数组为：
// | x | y | z | ? |
// |<----->|
// 而新元素n的pos为1，那么数组将移动y和z两个元素
// | x | y | y | z |
// |<----->|
// 这样就可以将新元素设置到pos上了：
// | x | n | y | z |
// T = O(N)
if (pos < intrev32ifbe(is->length)) intsetMoveTail(is,pos,pos+1);
}
// 将新值设置到底层数组的指定位置中
_intsetSet(is,pos,value);
// 增一集合元素数量的计数器
is->length = intrev32ifbe(intrev32ifbe(is->length)+1);
// 返回添加新元素后的整数集合
return is;
/* p.s.上面的代码可以重构成以下更简单的形式：
if (valenc > intrev32(is->encoding)) {
return intsetUpgradeAndAdd(is, value);
}
if (intsetSearch(is, value, &pos)) {
if (success) *success = 0;
return is;
} else {
is = intsetResize(is, intrev32ifbe(is->length) + 1);
if (pos < intrev32ifbe(is->length)) intsetMoveTail(is, pos, pos + 1);
_intsetSet(is, pos, value);
is->length = intrev32ifbe(intrev32ifbe(is->length) + 1);
return is;
}
*/
}
