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util/IntrusiveHashSet: add template argument GetKey

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This is a big simplification of all IntrusiveHashSet users: instead of
having to implement multiple overloads of Hash and Equal, the
IntrusiveHashSet class can first extract the effective key from an
item and then pass it to the Hash/Equal functions.
This commit is contained in:
Max Kellermann
2023-08-02 22:04:00 +02:00
committed by Max Kellermann
parent 78801f303e
commit 83a6cb804b
4 changed files with 33 additions and 81 deletions
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30
src/util/IntrusiveHashSet.hxx
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@@ -75,7 +75,12 @@ struct IntrusiveHashSetMemberHookTraits {
}
};
template<typename Hash, typename Equal>
/**
* @param GetKey a function object which extracts the "key" part of an
* item
*/
template<typename Hash, typename Equal,
typename GetKey=std::identity>
struct IntrusiveHashSetOperators {
using hasher = Hash;
using key_equal = Equal;
@@ -85,6 +90,9 @@ struct IntrusiveHashSetOperators {
[[no_unique_address]]
Equal equal;
[[no_unique_address]]
GetKey get_key;
};
/**
@@ -214,7 +222,7 @@ public:
Disposer<value_type> auto disposer) noexcept {
auto &bucket = GetBucket(key);
std::size_t n = bucket.remove_and_dispose_if([this, &key](const auto &item){
return ops.equal(key, item);
return ops.equal(key, ops.get_key(item));
}, disposer);
counter -= n;
return n;
@@ -225,7 +233,7 @@ public:
Disposer<value_type> auto disposer) noexcept {
auto &bucket = GetBucket(key);
std::size_t n = bucket.remove_and_dispose_if([this, &key, &pred](const auto &item){
return ops.equal(key, item) && pred(item);
return ops.equal(key, ops.get_key(item)) && pred(item);
}, disposer);
counter -= n;
return n;
@@ -247,7 +255,7 @@ public:
constexpr std::pair<bucket_iterator, bool> insert_check(const auto &key) noexcept {
auto &bucket = GetBucket(key);
for (auto &i : bucket)
if (ops.equal(key, i))
if (ops.equal(key, ops.get_key(i)))
return {bucket.iterator_to(i), false};
/* bucket.end() is a pointer to the bucket's list
@@ -267,7 +275,7 @@ public:
/* using insert_after() so the new item gets inserted
at the front of the bucket list */
GetBucket(item).insert_after(bucket, item);
GetBucket(ops.get_key(item)).insert_after(bucket, item);
}
/**
@@ -276,12 +284,12 @@ public:
*/
constexpr void insert(reference item) noexcept {
++counter;
GetBucket(item).push_front(item);
GetBucket(ops.get_key(item)).push_front(item);
}
constexpr bucket_iterator erase(bucket_iterator i) noexcept {
--counter;
return GetBucket(*i).erase(i);
return GetBucket(ops.get_key(*i)).erase(i);
}
constexpr bucket_iterator erase_and_dispose(bucket_iterator i,
@@ -295,7 +303,7 @@ public:
constexpr bucket_iterator find(const auto &key) noexcept {
auto &bucket = GetBucket(key);
for (auto &i : bucket)
if (ops.equal(key, i))
if (ops.equal(key, ops.get_key(i)))
return bucket.iterator_to(i);
return end();
@@ -305,7 +313,7 @@ public:
constexpr const_bucket_iterator find(const auto &key) const noexcept {
auto &bucket = GetBucket(key);
for (auto &i : bucket)
if (ops.equal(key, i))
if (ops.equal(key, ops.get_key(i)))
return bucket.iterator_to(i);
return end();
@@ -322,7 +330,7 @@ public:
std::predicate<const_reference> auto pred) noexcept {
auto &bucket = GetBucket(key);
for (auto &i : bucket)
if (ops.equal(key, i) && pred(i))
if (ops.equal(key, ops.get_key(i)) && pred(i))
return bucket.iterator_to(i);
return end();
@@ -349,7 +357,7 @@ public:
auto &bucket = GetBucket(key);
for (auto i = bucket.begin(), e = bucket.end(); i != e;) {
if (!ops.equal(key, *i))
if (!ops.equal(key, ops.get_key(*i)))
++i;
else if (expired_pred(*i))
i = erase_and_dispose(i, disposer);