Files
cocos-engine/native/cocos/base/StringPool.h
2022-01-24 17:18:47 +08:00

135 lines
4.6 KiB
C++

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#pragma once
#include <cstring>
#include <map>
#include <vector>
#include "StringHandle.h"
#include "base/Macros.h"
#include "threading/ReadWriteLock.h"
namespace cc {
struct StringCompare final {
inline bool operator()(char const *lhs, char const *rhs) const noexcept {
return strcmp(lhs, rhs) < 0;
}
};
template <bool ThreadSafe>
class StringPool final {
public:
StringPool() = default;
~StringPool();
StringPool(const StringPool &) = delete;
StringPool(StringPool &&) = delete;
StringPool &operator=(const StringPool &) = delete;
StringPool &operator=(StringPool &&) = delete;
StringHandle stringToHandle(const char *str) noexcept;
char const * handleToString(const StringHandle &handle) const noexcept;
StringHandle find(const char *str) const noexcept;
private:
StringHandle doStringToHandle(const char *str) noexcept;
char const * doHandleToString(const StringHandle &handle) const noexcept;
StringHandle doFind(const char *str) const noexcept;
std::map<char const *, StringHandle, StringCompare> _stringToHandles{};
std::vector<char const *> _handleToStrings{};
mutable ReadWriteLock _readWriteLock{};
};
using ThreadSafeStringPool = StringPool<true>;
template <bool ThreadSafe>
StringPool<ThreadSafe>::~StringPool() {
for (char const *strCache : _handleToStrings) {
delete[] strCache;
}
}
template <bool ThreadSafe>
inline StringHandle StringPool<ThreadSafe>::stringToHandle(const char *str) noexcept {
if (ThreadSafe) {
return _readWriteLock.lockWrite([this, str]() {
return doStringToHandle(str);
});
}
return doStringToHandle(str);
}
template <bool ThreadSafe>
inline char const *StringPool<ThreadSafe>::handleToString(const StringHandle &handle) const noexcept {
if (ThreadSafe) {
return _readWriteLock.lockRead([this, handle]() {
return doHandleToString(handle);
});
}
return doHandleToString(handle);
}
template <bool ThreadSafe>
StringHandle StringPool<ThreadSafe>::find(const char *str) const noexcept {
if (ThreadSafe) {
return _readWriteLock.lockRead([this, str]() {
return doFind(str);
});
}
return doFind(str);
}
template <bool ThreadSafe>
inline StringHandle StringPool<ThreadSafe>::doStringToHandle(const char *str) noexcept {
const auto it = _stringToHandles.find(str);
if (it == _stringToHandles.end()) {
size_t const strLength = strlen(str) + 1;
char *const strCache = new char[strLength];
strcpy(strCache, str);
StringHandle name(static_cast<StringHandle::IndexType>(_handleToStrings.size()), strCache);
_handleToStrings.emplace_back(strCache);
_stringToHandles.emplace(strCache, name);
return name;
}
return it->second;
}
template <bool ThreadSafe>
inline const char *StringPool<ThreadSafe>::doHandleToString(const StringHandle &handle) const noexcept {
CC_ASSERT(handle < _handleToStrings.size());
return _handleToStrings[handle];
}
template <bool ThreadSafe>
StringHandle StringPool<ThreadSafe>::doFind(char const *str) const noexcept {
auto const it = _stringToHandles.find(str);
return it == _stringToHandles.end() ? StringHandle{} : it->second;
}
} // namespace cc