kernel: Ensure `dict` always hashes to the same value given the same contents.

This commit is contained in:
Alberto Gonzalez 2020-04-24 08:37:16 +00:00
parent 35b94d1f66
commit 976edb7597
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GPG Key ID: 8395A8BA109708B2
1 changed files with 6 additions and 3 deletions

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@ -207,6 +207,7 @@ class dict
entry_t() { }
entry_t(const std::pair<K, T> &udata, int next) : udata(udata), next(next) { }
entry_t(std::pair<K, T> &&udata, int next) : udata(std::move(udata)), next(next) { }
bool operator<(const entry_t &other) const { return udata.first < other.udata.first; }
};
std::vector<int> hashtable;
@ -616,10 +617,12 @@ public:
}
unsigned int hash() const {
std::vector<entry_t> entries_(entries); //make a copy to preserve const-ness
std::sort(entries_.begin(), entries_.end());
unsigned int h = mkhash_init;
for (auto &it : entries) {
h = mkhash(h, hash_ops<K>::hash(it.udata.first));
h = mkhash(h, hash_ops<T>::hash(it.udata.second));
for (unsigned int i = 0; i < entries_.size(); ++i) {
h = mkhash(h, hash_ops<K>::hash(entries_[i].udata.first));
h = mkhash(h, hash_ops<T>::hash(entries_[i].udata.second));
}
return h;
}