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#ifndef shared_string_hh_INCLUDED
#define shared_string_hh_INCLUDED
#include "string.hh"
#include "ref_ptr.hh"
#include "utils.hh"
#include "unordered_map.hh"
namespace Kakoune
{
struct StringData : UseMemoryDomain<MemoryDomain::SharedString>
{
int refcount;
int length;
uint32_t hash;
StringData(int ref, int len) : refcount(ref), length(len) {}
[[gnu::always_inline]]
char* data() { return reinterpret_cast<char*>(this + 1); }
[[gnu::always_inline]]
const char* data() const { return reinterpret_cast<const char*>(this + 1); }
[[gnu::always_inline]]
StringView strview() const { return {data(), length}; }
static RefPtr<StringData> create(StringView str, char back = 0)
{
const int len = (int)str.length() + (back != 0 ? 1 : 0);
void* ptr = StringData::operator new(sizeof(StringData) + len + 1);
StringData* res = new (ptr) StringData(0, len);
std::copy(str.begin(), str.end(), res->data());
if (back != 0)
res->data()[len-1] = back;
res->data()[len] = 0;
res->hash = hash_data(res->data(), res->length);
return RefPtr<StringData>(res);
}
static void destroy(StringData* s)
{
StringData::operator delete(s, sizeof(StringData) + s->length + 1);
}
friend void inc_ref_count(StringData* s, void*)
{
++s->refcount;
}
friend void dec_ref_count(StringData* s, void*)
{
if (--s->refcount == 0)
StringData::destroy(s);
}
};
using StringDataPtr = RefPtr<StringData>;
inline StringDataPtr operator"" _ss(const char* ptr, size_t len)
{
return StringData::create({ptr, (int)len});
}
class SharedString : public StringView
{
public:
SharedString() = default;
SharedString(StringView str)
{
if (not str.empty())
{
m_storage = StringData::create(str);
StringView::operator=(m_storage->strview());
}
}
struct NoCopy{};
SharedString(StringView str, NoCopy) : StringView(str) {}
SharedString(const char* str) : SharedString(StringView{str}) {}
SharedString acquire_substr(ByteCount from, ByteCount length = INT_MAX) const
{
return SharedString{StringView::substr(from, length), m_storage};
}
SharedString acquire_substr(CharCount from, CharCount length = INT_MAX) const
{
return SharedString{StringView::substr(from, length), m_storage};
}
explicit SharedString(StringDataPtr storage)
: StringView{storage->strview()}, m_storage(std::move(storage)) {}
friend size_t hash_value(const SharedString& str)
{
return str.m_storage ? str.m_storage->hash : hash_data(str.data(), (int)str.length());
}
private:
SharedString(StringView str, StringDataPtr storage)
: StringView{str}, m_storage(std::move(storage)) {}
friend class StringRegistry;
StringDataPtr m_storage;
};
class StringRegistry : public Singleton<StringRegistry>
{
public:
void debug_stats() const;
SharedString intern(StringView str);
void purge_unused();
private:
UnorderedSet<SharedString, MemoryDomain::SharedString> m_strings;
};
inline SharedString intern(StringView str)
{
return StringRegistry::instance().intern(str);
}
}
#endif // shared_string_hh_INCLUDED
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