Professional games use several strategies to handle large amounts of save data efficiently:
Incremental Saving
Instead of saving everything at once, games often save different components independently:
#include <chrono>
using namespace std::chrono;
class SaveManager {
steady_clock::time_point LastInventorySave;
steady_clock::time_point LastQuestSave;
public:
void Update() {
auto Now = steady_clock::now();
// Save inventory every 5 minutes
if (Now - LastInventorySave > minutes(5)) {
SaveInventory();
LastInventorySave = Now;
}
// Save quests every 10 minutes
if (Now - LastQuestSave > minutes(10)) {
SaveQuests();
LastQuestSave = Now;
}
}
void SaveInventory() {
// Only save items that changed since last save
for (const auto& Item : PlayerInventory) {
if (Item.HasChanged) {
WriteItemToFile(Item);
}
}
}
};Chunked World Data
Open world games typically divide the world into chunks and only save active areas:
struct WorldChunk {
static constexpr int SIZE = 64;
std::array<std::array<Tile, SIZE>, SIZE>
Tiles;
bool IsModified{false};
};
class World {
std::vector<std::vector<WorldChunk>> Chunks;
void SaveActiveChunks() {
const int PlayerChunkX = PlayerPos.X /
WorldChunk::SIZE;
const int PlayerChunkY = PlayerPos.Y /
WorldChunk::SIZE;
// Save chunks near player
for (int dx = -1; dx <= 1; ++dx) {
for (int dy = -1; dy <= 1; ++dy) {
SaveChunkIfModified(PlayerChunkX + dx,
PlayerChunkY + dy);
}
}
}
};Compression
Large save files are typically compressed before writing to disk:
#include <zlib.h>
#include <vector>
std::vector<char> CompressSaveData(
const std::vector<char>& Data) {
std::vector<char> CompressedData;
z_stream Stream{};
// Initialize zlib
deflateInit(&Stream, Z_BEST_COMPRESSION);
// Compress data in chunks
const int CHUNK_SIZE = 16384;
char OutBuffer[CHUNK_SIZE];
// Compression code here...
deflateEnd(&Stream);
return CompressedData;
}Reference Data
Instead of saving full copies of common objects, save references to shared data:
struct Item {
int TemplateId; // Reference to item template
int Count; // Instance-specific data
// Don't save template data like name, description, icon...
};This combination of techniques allows games to manage massive amounts of save data while maintaining reasonable file sizes and save/load times.
Answers to questions are automatically generated and may not have been reviewed.
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