Server Architecture

typedef struct {
  serverState_t state;
  int timeResidual;
  int frameusec;
  qboolean restarting;
  int serverId;
  int checksumFeed;
  
  unsigned short configstringIndex[MAX_CONFIGSTRINGS];
  svEntity_t svEntities[MAX_GENTITIES];
  
  sharedEntity_t* gentities;
  int gentitySize;
  int num_entities;
  
  playerState_t* gameClients;
  int gameClientSize;
  
  int bpsWindow[MAX_BPS_WINDOW];
  int bpsWindowSteps;
  int bpsTotalBytes;
  int bpsMaxBytes;
  
  char gametype[MAX_QPATH];
} server_t;

typedef struct {
  entityUnknownStr_t entUnknown1[512];
  archivedEntity_t archivedEntities[16384];
  
  qboolean initialized;
  int time;
  int snapFlagServerBit;
  
  client_t clients[MAX_CLIENTS];
  
  int numSnapshotEntities;
  int numSnapshotClients;
  int nextSnapshotEntities;
  int nextSnapshotClients;
  
  entityState_t snapshotEntities[0x2A000];
  clientState_ts snapshotClients[0x20000];
  
  int nextHeartbeatTime;
  challenge2_t challenges[MAX_CHALLENGES];
  
  int redirectAddress[5];
  int authorizeAddress[5];
  
  char netProfilingBuf[1504];
  banlist_t banlist[16];
  vec3_t mapCenter;
} serverStatic_t;

typedef enum {
  CS_FREE,      // can be reused for a new connection
  CS_ZOMBIE,    // client disconnected, don't reuse yet
  CS_CONNECTED, // assigned to client_t, no gamestate yet
  CS_PRIMED,    // gamestate sent, awaiting usercmd
  CS_ACTIVE     // client fully in game
} clientState_t;

typedef struct client_s {
  clientState_t state;
  int deltaMessage;
  qboolean rateDelayed;
  netchan_t netchan;
  
  // Demo recording
  fileHandleData_t demofile;
  qboolean demorecording;
  char demoName[MAX_QPATH];
  
  // Authentication
  int authentication;
  qboolean playerauthorized;
  int uid;
  char pbguid[33];
  
  // Connection info
  char name[64];
  char userinfo[MAX_INFO_STRING];
  
  // Reliable commands
  reliableCommands_t reliableCommands[MAX_RELIABLE_COMMANDS];
  int reliableSequence;
  int reliableAcknowledge;
  
  // Snapshots
  clientSnapshot_t frames[PACKET_BACKUP];
  int ping;
  int rate;
  int snapshotMsec;
  
  // Downloads
  char downloadName[MAX_QPATH];
  fileHandle_t download;
  int downloadSize;
  int downloadCount;
  
  // Network buffers
  byte unsentBuffer[NETCHAN_UNSENTBUFFER_SIZE];
  byte fragmentBuffer[NETCHAN_FRAGMENTBUFFER_SIZE];
} client_t;

// Frame timing is calculated based on sv_fps
frameusec = 1000000 / sv_fps->integer;
timeResidual += usec;

while (timeResidual >= frameusec) {
  timeResidual -= frameusec;
  // Process server frame
}

typedef struct svEntity_s {
  struct svEntity_s* nextEntityInWorldSector;
  
  entityState_t baseline;  // For delta compression
  int numClusters;
  int clusternums[MAX_ENT_CLUSTERS];
  int lastCluster;
  int areanum, areanum2;
  int snapshotCounter;  // Prevent double adding
} svEntity_t;

typedef struct {
  playerState_t ps;
  int num_entities;
  int num_clients;
  int first_entity;
  int first_client;
  
  unsigned int messageSent;
  unsigned int messageAcked;
  int messageSize;
} clientSnapshot_t;

typedef struct {
  int max_buckets;
  int max_hashes;
  leakyBucket_t* buckets;
  leakyBucket_t** bucketHashes;
  int queryLimitsEnabled;
  leakyBucket_t infoBucket;
  leakyBucket_t statusBucket;
  leakyBucket_t rconBucket;
} queryLimit_t;