kakoune/src/shared_string.cc
Maxime Coste d9abc2a156 Refactor StringData and StringRegistry to remove need for purging
Purging unused strings could get pretty expensive with a lot of
interned strings as it requiered iterating on all of them. Use
a flag on the refcount of the StringData to see if the string
is interned, and notify the StringRegistry in this case.

This should improve the speed of editing big files with many words,
such as the one described in #1195
2017-02-23 00:03:32 +00:00

59 lines
1.7 KiB
C++

#include "shared_string.hh"
#include "buffer_utils.hh"
namespace Kakoune
{
StringDataPtr StringData::create(ArrayView<const StringView> strs)
{
const int len = std::accumulate(strs.begin(), strs.end(), 0,
[](int l, StringView s)
{ return l + (int)s.length(); });
void* ptr = StringData::operator new(sizeof(StringData) + len + 1);
auto* res = new (ptr) StringData(len);
auto* data = reinterpret_cast<char*>(res + 1);
for (auto& str : strs)
{
memcpy(data, str.begin(), (size_t)str.length());
data += (int)str.length();
}
*data = 0;
return RefPtr<StringData, PtrPolicy>{res};
}
StringDataPtr StringData::Registry::intern(StringView str)
{
auto it = m_strings.find(str);
if (it != m_strings.end())
return StringDataPtr{it->second};
auto data = StringData::create(str);
data->refcount |= interned_flag;
m_strings.emplace(data->strview(), data.get());
return data;
}
void StringData::Registry::remove(StringView str)
{
auto it = m_strings.find(str);
kak_assert(it != m_strings.end());
m_strings.erase(it);
}
void StringData::Registry::debug_stats() const
{
write_to_debug_buffer("Shared Strings stats:");
size_t total_refcount = 0;
size_t total_size = 0;
size_t count = m_strings.size();
for (auto& st : m_strings)
{
total_refcount += st.second->refcount - 1;
total_size += (int)st.second->length;
}
write_to_debug_buffer(format(" data size: {}, mean: {}", total_size, (float)total_size/count));
write_to_debug_buffer(format(" refcounts: {}, mean: {}", total_refcount, (float)total_refcount/count));
}
}