ku_string.h

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#pragma once
 
#include <cstdint>
#include <cstring>
#include <string>
 
#include "api.h"
 
namespace kuzu {
namespace common {
 
struct KUZU_API ku_string_t {
 
 static constexpr uint64_t PREFIX_LENGTH = 4;
 static constexpr uint64_t INLINED_SUFFIX_LENGTH = 8;
 static constexpr uint64_t SHORT_STR_LENGTH = PREFIX_LENGTH + INLINED_SUFFIX_LENGTH;
 
 uint32_t len;
 uint8_t prefix[PREFIX_LENGTH];
 union {
 uint8_t data[INLINED_SUFFIX_LENGTH];
 uint64_t overflowPtr;
 };
 
 ku_string_t() : len{0}, overflowPtr{0} {}
 ku_string_t(const char* value, uint64_t length);
 
 static bool isShortString(uint32_t len) { return len <= SHORT_STR_LENGTH; }
 
 const uint8_t* getData() const {
 return isShortString(len) ? prefix : reinterpret_cast<uint8_t*>(overflowPtr);
 }
 
 uint8_t* getDataUnsafe() {
 return isShortString(len) ? prefix : reinterpret_cast<uint8_t*>(overflowPtr);
 }
 
 // These functions do *NOT* allocate/resize the overflow buffer, it only copies the content and
 // set the length.
 void set(const std::string& value);
 void set(const char* value, uint64_t length);
 void set(const ku_string_t& value);
 void setShortString(const char* value, uint64_t length) {
 this->len = length;
 memcpy(prefix, value, length);
 }
 void setLongString(const char* value, uint64_t length) {
 this->len = length;
 memcpy(prefix, value, PREFIX_LENGTH);
 memcpy(reinterpret_cast<char*>(overflowPtr), value, length);
 }
 void setShortString(const ku_string_t& value) {
 this->len = value.len;
 memcpy(prefix, value.prefix, value.len);
 }
 void setLongString(const ku_string_t& value) {
 this->len = value.len;
 memcpy(prefix, value.prefix, PREFIX_LENGTH);
 memcpy(reinterpret_cast<char*>(overflowPtr), reinterpret_cast<char*>(value.overflowPtr),
 value.len);
 }
 
 void setFromRawStr(const char* value, uint64_t length) {
 this->len = length;
 if (isShortString(length)) {
 setShortString(value, length);
 } else {
 memcpy(prefix, value, PREFIX_LENGTH);
 overflowPtr = reinterpret_cast<uint64_t>(value);
 }
 }
 
 std::string getAsShortString() const;
 std::string getAsString() const;
 std::string_view getAsStringView() const;
 
 bool operator==(const ku_string_t& rhs) const;
 
 inline bool operator!=(const ku_string_t& rhs) const { return !(*this == rhs); }
 
 bool operator>(const ku_string_t& rhs) const;
 
 inline bool operator>=(const ku_string_t& rhs) const { return (*this > rhs) || (*this == rhs); }
 
 inline bool operator<(const ku_string_t& rhs) const { return !(*this >= rhs); }
 
 inline bool operator<=(const ku_string_t& rhs) const { return !(*this > rhs); }
};
 
} // namespace common
} // namespace kuzu