Skip to content
New issue

Have a question about this project? Sign up for a free GitHub account to open an issue and contact its maintainers and the community.

Sign up for GitHub

By clicking “Sign up for GitHub”, you agree to our terms of service and privacy statement. We’ll occasionally send you account related emails.

Already on GitHub? Sign in to your account

Jump to bottom

Fix copy-on-write semantics of HashMap for remove/clear #1

Merged
merged 1 commit into from
Nov 27, 2023
Merged

Fix copy-on-write semantics of HashMap for remove/clear #1

Changes from all commits
Commits
Show all changes
1 commit
Select commit
File filter

Filter by extension

Filter by extension
Conversations
Failed to load comments.
Loading
Jump to
Jump to file
Failed to load files.
Loading
Diff view
Diff view
44 changes: 27 additions & 17 deletions source/vibe/container/hashmap.d
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -150,6 +150,8 @@ struct HashMap(TKey, TValue, Traits = DefaultHashMapTraits!TKey, Allocator = IAl
{
import std.algorithm.mutation : move;

makeUnique();

auto idx = findIndex(key);
assert (idx != size_t.max, "Removing non-existent element.");
auto i = idx;
Expand Down Expand Up @@ -198,6 +200,7 @@ struct HashMap(TKey, TValue, Traits = DefaultHashMapTraits!TKey, Allocator = IAl

void clear()
{
makeUnique();
foreach (i; 0 .. m_table.length)
if (!Traits.equals(m_table[i].key, Traits.clearValue)) {
m_table[i].key = Traits.clearValue;
Expand Down Expand Up @@ -305,32 +308,39 @@ struct HashMap(TKey, TValue, Traits = DefaultHashMapTraits!TKey, Allocator = IAl
}

private void grow(size_t amount)
@trusted {
@safe {
auto newsize = m_length + amount;
if (newsize < (m_table.length*2)/3) {
int rc;
try rc = allocator.prefix(m_table);
catch (Exception e) assert(false, e.msg);
if (rc > 1) {
// enforce copy-on-write
auto oldtable = m_table;
try {
m_table = allocator.makeArray!TableEntry(m_table.length);
m_table[] = oldtable;
allocator.prefix(oldtable)--;
assert(allocator.prefix(oldtable) > 0);
allocator.prefix(m_table) = 1;
} catch (Exception e) {
assert(false, e.msg);
}
}
makeUnique();
return;
}
auto newcap = m_table.length ? m_table.length : 16;
while (newsize >= (newcap*2)/3) newcap *= 2;
resize(newcap);
}

private void makeUnique()
@trusted {
if (m_table is null) return;

int rc;
try rc = allocator.prefix(m_table);
catch (Exception e) assert(false, e.msg);
if (rc > 1) {
// enforce copy-on-write
auto oldtable = m_table;
try {
m_table = allocator.makeArray!TableEntry(m_table.length);
m_table[] = oldtable;
allocator.prefix(oldtable)--;
assert(allocator.prefix(oldtable) > 0);
allocator.prefix(m_table) = 1;
} catch (Exception e) {
assert(false, e.msg);
}
}
}

private void resize(size_t new_size)
@trusted {
assert(!m_resizing);
Expand Down