ebc9881999-05-06Henrik Grubbström (Grubba) /*
366b791999-05-16Henrik Grubbström (Grubba)  * $Id: Roxen.pmod,v 1.7 1999/05/16 15:36:46 grubba Exp $
ebc9881999-05-06Henrik Grubbström (Grubba)  * * Various helper functions. * * Henrik Grubbström 1999-05-03 */ /* * TODO: * * o Quota: Fix support for the index file. * */ #ifdef QUOTA_DEBUG #define QD_WRITE(X) werror(X) #else /* !QUOTA_DEBUG */ #define QD_WRITE(X) #endif /* QUOTA_DEBUG */ class QuotaDB { #if constant(create_thread) object(Thread.Mutex) lock = Thread.Mutex(); #define LOCK() mixed key__; catch { _key = lock->lock(); } #define UNLOCK() do { if (key__) destruct(key__); } while(0) #else /* !constant(create_thread) */ #define LOCK() #define UNLOCK() #endif /* constant(create_thread) */ constant READ_BUF_SIZE = 256; constant CACHE_SIZE_LIMIT = 512;
a3e4271999-05-11Henrik Grubbström (Grubba)  string base;
ebc9881999-05-06Henrik Grubbström (Grubba)  object catalog_file; object data_file; mapping(string:int) new_entries_cache = ([]); mapping(string:object) active_objects = ([]); array(int) index;
e9857a1999-05-08Henrik Grubbström (Grubba)  array(string) index_acc; int acc_scale;
ebc9881999-05-06Henrik Grubbström (Grubba)  int next_offset; static class QuotaEntry { string name; int data_offset;
eed7141999-05-12Henrik Grubbström (Grubba)  static int usage;
ebc9881999-05-06Henrik Grubbström (Grubba)  static int quota; static void store() { LOCK();
eed7141999-05-12Henrik Grubbström (Grubba)  QD_WRITE(sprintf("QuotaEntry::store(): Usage for %O is now %O(%O)\n", name, usage, quota));
ebc9881999-05-06Henrik Grubbström (Grubba)  data_file->seek(data_offset);
eed7141999-05-12Henrik Grubbström (Grubba)  data_file->write(sprintf("%4c", usage));
ebc9881999-05-06Henrik Grubbström (Grubba)  UNLOCK(); } static void read() { LOCK(); data_file->seek(data_offset); string s = data_file->read(4);
eed7141999-05-12Henrik Grubbström (Grubba)  usage = 0; sscanf(s, "%4c", usage);
ebc9881999-05-06Henrik Grubbström (Grubba) 
eed7141999-05-12Henrik Grubbström (Grubba)  QD_WRITE(sprintf("QuotaEntry::read(): Usage for %O is %O(%O)\n", name, usage, quota));
ebc9881999-05-06Henrik Grubbström (Grubba)  UNLOCK(); }
eed7141999-05-12Henrik Grubbström (Grubba)  void create(string n, int d_o, int q)
ebc9881999-05-06Henrik Grubbström (Grubba)  {
eed7141999-05-12Henrik Grubbström (Grubba)  QD_WRITE(sprintf("QuotaEntry(%O, %O, %O)\n", n, d_o, q));
ebc9881999-05-06Henrik Grubbström (Grubba)  name = n; data_offset = d_o;
eed7141999-05-12Henrik Grubbström (Grubba)  quota = q;
ebc9881999-05-06Henrik Grubbström (Grubba)  read(); } int check_quota(string uri, int amount) {
eed7141999-05-12Henrik Grubbström (Grubba)  QD_WRITE(sprintf("QuotaEntry::check_quota(%O, %O): usage:%d(%d)\n", uri, amount, usage, quota)); if (!quota) { // No quota at all. return 0; }
ebc9881999-05-06Henrik Grubbström (Grubba)  if (amount == 0x7fffffff) { // Workaround for FTP. return 1; }
eed7141999-05-12Henrik Grubbström (Grubba)  return(usage + amount <= quota);
ebc9881999-05-06Henrik Grubbström (Grubba)  } int allocate(string uri, int amount) {
eed7141999-05-12Henrik Grubbström (Grubba)  QD_WRITE(sprintf("QuotaEntry::allocate(%O, %O): usage:%d => %d(%d)\n", uri, amount, usage, usage + amount, quota));
ebc9881999-05-06Henrik Grubbström (Grubba) 
eed7141999-05-12Henrik Grubbström (Grubba)  usage += amount;
ebc9881999-05-06Henrik Grubbström (Grubba)  store();
eed7141999-05-12Henrik Grubbström (Grubba)  return(usage <= quota);
ebc9881999-05-06Henrik Grubbström (Grubba)  } int deallocate(string uri, int amount) { return(allocate(uri, -amount)); }
eed7141999-05-12Henrik Grubbström (Grubba)  int get_usage(string uri)
ebc9881999-05-06Henrik Grubbström (Grubba)  {
eed7141999-05-12Henrik Grubbström (Grubba)  return usage;
ebc9881999-05-06Henrik Grubbström (Grubba)  }
eed7141999-05-12Henrik Grubbström (Grubba)  void set_usage(string uri, int amount)
ebc9881999-05-06Henrik Grubbström (Grubba)  {
eed7141999-05-12Henrik Grubbström (Grubba)  usage = amount;
ebc9881999-05-06Henrik Grubbström (Grubba)  store(); } #if !constant(set_weak_flag) static int refs; void add_ref() { refs++; } void free_ref() { if (!(--refs)) { destruct(); } } } static class QuotaProxy { static object(QuotaEntry) master; function(string, int:int) check_quota; function(string, int:int) allocate; function(string, int:int) deallocate;
eed7141999-05-12Henrik Grubbström (Grubba)  function(string, int:void) set_usage; function(string:int) get_usage;
ebc9881999-05-06Henrik Grubbström (Grubba)  void create(object(QuotaEntry) m) { master = m; master->add_ref(); check_quota = master->check_quota; allocate = master->allocate; deallocate = master->deallocate;
eed7141999-05-12Henrik Grubbström (Grubba)  set_usage = master->set_usage; get_usage = master->get_usage;
ebc9881999-05-06Henrik Grubbström (Grubba)  } void destroy() { master->free_ref(); } #endif /* !constant(set_weak_flag) */ }
eed7141999-05-12Henrik Grubbström (Grubba)  static object read_entry(int offset, int|void quota)
ebc9881999-05-06Henrik Grubbström (Grubba)  {
eed7141999-05-12Henrik Grubbström (Grubba)  QD_WRITE(sprintf("QuotaDB::read_entry(%O, %O)\n", offset, quota));
ebc9881999-05-06Henrik Grubbström (Grubba)  catalog_file->seek(offset); string data = catalog_file->read(READ_BUF_SIZE); if (data == "") {
eed7141999-05-12Henrik Grubbström (Grubba)  QD_WRITE(sprintf("QuotaDB::read_entry(%O, %O): At EOF\n", offset, quota));
ebc9881999-05-06Henrik Grubbström (Grubba)  return 0; } int len; int data_offset; string key; sscanf(data[..7], "%4c%4c", len, data_offset); if (len > sizeof(data)) { key = data[8..] + catalog_file->read(len - sizeof(data)); len -= 8; if (sizeof(key) != len) { error(sprintf("Failed to read catalog entry at offset %d.\n" "len: %d, sizeof(key):%d\n", offset, len, sizeof(key))); } } else { key = data[8..len-1];
6fa7e81999-05-14Henrik Grubbström (Grubba)  catalog_file->seek(offset + 8 + sizeof(key));
ebc9881999-05-06Henrik Grubbström (Grubba)  }
eed7141999-05-12Henrik Grubbström (Grubba)  return QuotaEntry(key, data_offset, quota);
ebc9881999-05-06Henrik Grubbström (Grubba)  } static object open(string fname, int|void create_new) { object f = Stdio.File(); string mode = create_new?"rwc":"rw"; if (!f->open(fname, mode)) { error(sprintf("Failed to open quota file %O.\n", fname)); } if (f->try_lock && !f->try_lock()) { error(sprintf("Failed to lock quota file %O.\n", fname)); } return(f); }
e9857a1999-05-08Henrik Grubbström (Grubba)  static void init_index_acc() { /* Set up the index accellerator. * sizeof(index_acc) ~ sqrt(sizeof(index)) */ acc_scale = 1; if (sizeof(index)) { int i = sizeof(index)/2; while (i) { i /= 4; acc_scale <<= 1; } } index_acc = allocate(sizeof(index)/acc_scale); QD_WRITE(sprintf("QuotaDB()::init_index_acc(): " "sizeof(index):%d, sizeof(index_acc):%d acc_scale:%d\n", sizeof(index), sizeof(index_acc), acc_scale)); }
1a7b001999-05-14Henrik Grubbström (Grubba)  void rebuild_index()
ebc9881999-05-06Henrik Grubbström (Grubba)  { // FIXME: Actually make an index file.
a3e4271999-05-11Henrik Grubbström (Grubba)  array(string) new_keys = sort(indices(new_entries_cache)); int prev; array(int) new_index = ({}); foreach(new_keys, string key) { int lo; int hi = sizeof(index_acc);
eed7141999-05-12Henrik Grubbström (Grubba)  if (hi) { do {
366b791999-05-16Henrik Grubbström (Grubba)  // Loop invariants: // hi is an element > key. // lo-1 is an element < key.
eed7141999-05-12Henrik Grubbström (Grubba)  int probe = (lo + hi)/2; if (!index_acc[probe]) { object e = read_entry(index[probe * acc_scale]); index_acc[probe] = e->name; } if (index_acc[probe] < key) {
366b791999-05-16Henrik Grubbström (Grubba)  lo = probe + 1;
eed7141999-05-12Henrik Grubbström (Grubba)  } else if (index_acc[probe] > key) { hi = probe; } else { /* Found */ // Shouldn't happen... break; }
366b791999-05-16Henrik Grubbström (Grubba)  } while(lo < hi);
eed7141999-05-12Henrik Grubbström (Grubba) 
366b791999-05-16Henrik Grubbström (Grubba)  if (lo < hi) {
eed7141999-05-12Henrik Grubbström (Grubba)  // Found... // Shouldn't happen, but... // Skip to the next key... continue;
a3e4271999-05-11Henrik Grubbström (Grubba)  }
eed7141999-05-12Henrik Grubbström (Grubba)  hi *= acc_scale;
366b791999-05-16Henrik Grubbström (Grubba)  lo = hi - acc_scale;
eed7141999-05-12Henrik Grubbström (Grubba)  do {
366b791999-05-16Henrik Grubbström (Grubba)  // Same loop invariants as above.
eed7141999-05-12Henrik Grubbström (Grubba)  int probe = (lo + hi)/2; object e = read_entry(index[probe]); if (e->name < key) {
366b791999-05-16Henrik Grubbström (Grubba)  lo = probe + 1;
eed7141999-05-12Henrik Grubbström (Grubba)  } else if (e->name > key) { hi = probe; } else { /* Found */ // Shouldn't happen... break; }
366b791999-05-16Henrik Grubbström (Grubba)  } while (lo < hi); if (lo < hi) {
eed7141999-05-12Henrik Grubbström (Grubba)  // Found... // Shouldn't happen, but... // Skip to the next key... continue;
a3e4271999-05-11Henrik Grubbström (Grubba)  }
366b791999-05-16Henrik Grubbström (Grubba)  new_index += index[prev..hi-1] + ({ new_entries_cache[key] });
eed7141999-05-12Henrik Grubbström (Grubba)  prev = hi; } else { new_index += ({ new_entries_cache[key] });
a3e4271999-05-11Henrik Grubbström (Grubba)  } } LOCK(); object index_file = open(base + ".index.new", 1); string to_write = sprintf("%@4c", new_index); if (index_file->write(to_write) != sizeof(to_write)) { index_file->close(); rm(base + ".index.new"); } else { mv(base + ".index.new", base + ".index"); } index = new_index; init_index_acc(); UNLOCK(); foreach(new_keys, string key) { m_delete(new_entries_cache, key); }
ebc9881999-05-06Henrik Grubbström (Grubba)  }
eed7141999-05-12Henrik Grubbström (Grubba)  static object low_lookup(string key, int quota)
ebc9881999-05-06Henrik Grubbström (Grubba)  {
eed7141999-05-12Henrik Grubbström (Grubba)  QD_WRITE(sprintf("QuotaDB::low_lookup(%O, %O)\n", key, quota));
ebc9881999-05-06Henrik Grubbström (Grubba) 
a3e4271999-05-11Henrik Grubbström (Grubba)  int cat_offset;
ebc9881999-05-06Henrik Grubbström (Grubba) 
a3e4271999-05-11Henrik Grubbström (Grubba)  if (!zero_type(cat_offset = new_entries_cache[key])) {
eed7141999-05-12Henrik Grubbström (Grubba)  QD_WRITE(sprintf("QuotaDB::low_lookup(%O, %O): " "Found in new entries cache.\n", key, quota)); return read_entry(cat_offset, quota);
e9857a1999-05-08Henrik Grubbström (Grubba)  } /* Try the index file. */
ebc9881999-05-06Henrik Grubbström (Grubba) 
e9857a1999-05-08Henrik Grubbström (Grubba)  /* First use the accellerated index. */ int lo; int hi = sizeof(index_acc);
eed7141999-05-12Henrik Grubbström (Grubba)  if (hi) { do {
366b791999-05-16Henrik Grubbström (Grubba)  // Loop invariants: // hi is an element that is > key. // lo-1 is an element that is < key.
eed7141999-05-12Henrik Grubbström (Grubba)  int probe = (lo + hi)/2;
ebc9881999-05-06Henrik Grubbström (Grubba) 
366b791999-05-16Henrik Grubbström (Grubba)  QD_WRITE(sprintf("QuotaDB:low_lookup(%O): " "In acc: lo:%d, probe:%d, hi:%d\n", key, lo, probe, hi));
eed7141999-05-12Henrik Grubbström (Grubba)  if (!index_acc[probe]) { object e = read_entry(index[probe * acc_scale], quota);
e9857a1999-05-08Henrik Grubbström (Grubba) 
eed7141999-05-12Henrik Grubbström (Grubba)  index_acc[probe] = e->name;
e9857a1999-05-08Henrik Grubbström (Grubba) 
eed7141999-05-12Henrik Grubbström (Grubba)  if (key == e->name) { /* Found in e */ QD_WRITE(sprintf("QuotaDB:low_lookup(%O): In acc: Found at %d\n", key, probe * acc_scale)); return e; } } if (index_acc[probe] < key) {
366b791999-05-16Henrik Grubbström (Grubba)  lo = probe + 1;
eed7141999-05-12Henrik Grubbström (Grubba)  } else if (index_acc[probe] > key) { hi = probe; } else { /* Found */
e9857a1999-05-08Henrik Grubbström (Grubba)  QD_WRITE(sprintf("QuotaDB:low_lookup(%O): In acc: Found at %d\n", key, probe * acc_scale));
eed7141999-05-12Henrik Grubbström (Grubba)  return read_entry(index[probe * acc_scale], quota);
e9857a1999-05-08Henrik Grubbström (Grubba)  }
366b791999-05-16Henrik Grubbström (Grubba)  } while(lo < hi); // At this point hi is the first element that is > key. // Not in the accellerated index.
ebc9881999-05-06Henrik Grubbström (Grubba) 
366b791999-05-16Henrik Grubbström (Grubba)  if (hi) { // Go to disk hi *= acc_scale; lo = hi - acc_scale; do { // Same loop invariant as above. int probe = (lo + hi)/2; QD_WRITE(sprintf("QuotaDB:low_lookup(%O): lo:%d, probe:%d, hi:%d\n", key, lo, probe, hi)); object e = read_entry(index[probe], quota);
eed7141999-05-12Henrik Grubbström (Grubba) 
366b791999-05-16Henrik Grubbström (Grubba)  if (e->name < key) { lo = probe + 1; } else if (e->name > key) { hi = probe; } else { /* Found */ QD_WRITE(sprintf("QuotaDB:low_lookup(%O): Found at %d\n", key, probe)); return e; } } while (lo < hi); }
e9857a1999-05-08Henrik Grubbström (Grubba)  } QD_WRITE(sprintf("QuotaDB::low_lookup(%O): Not found\n", key)); return 0;
ebc9881999-05-06Henrik Grubbström (Grubba)  } object lookup(string key, int quota) { QD_WRITE(sprintf("QuotaDB::lookup(%O, %O)\n", key, quota)); LOCK(); object res; if (res = active_objects[key]) { QD_WRITE(sprintf("QuotaDB::lookup(%O, %O): User in active objects.\n", key, quota)); #if constant(set_weak_flag) return res; #else /* !constant(set_weak_flag) */ return QuotaProxy(res); #endif /* constant(set_weak_flag) */ }
eed7141999-05-12Henrik Grubbström (Grubba)  if (res = low_lookup(key, quota)) {
e9857a1999-05-08Henrik Grubbström (Grubba)  active_objects[key] = res; #if constant(set_weak_flag)
ebc9881999-05-06Henrik Grubbström (Grubba)  return res;
e9857a1999-05-08Henrik Grubbström (Grubba) #else /* !constant(set_weak_flag) */ return QuotaProxy(res); #endif /* constant(set_weak_flag) */
ebc9881999-05-06Henrik Grubbström (Grubba)  } QD_WRITE(sprintf("QuotaDB::lookup(%O, %O): New user.\n", key, quota)); // Search to EOF. data_file->seek(-1); data_file->read(1); catalog_file->seek(next_offset); // We should now be at EOF. int data_offset = data_file->tell(); // Initialize.
eed7141999-05-12Henrik Grubbström (Grubba)  if (data_file->write(sprintf("%4c", 0)) != 4) {
ebc9881999-05-06Henrik Grubbström (Grubba)  error(sprintf("write() failed for quota data file!\n")); } string entry = sprintf("%4c%4c%s", sizeof(key)+8, data_offset, key); if (catalog_file->write(entry) != sizeof(entry)) { error(sprintf("write() failed for quota catalog file!\n")); } new_entries_cache[key] = next_offset; next_offset = catalog_file->tell(); if (sizeof(new_entries_cache) > CACHE_SIZE_LIMIT) { rebuild_index(); } // low_lookup will always succeed at this point.
eed7141999-05-12Henrik Grubbström (Grubba)  return low_lookup(key, quota);
ebc9881999-05-06Henrik Grubbström (Grubba)  } void create(string base_name, int|void create_new) {
a3e4271999-05-11Henrik Grubbström (Grubba)  base = base_name;
ebc9881999-05-06Henrik Grubbström (Grubba)  catalog_file = open(base_name + ".cat", create_new); data_file = open(base_name + ".data", create_new);
a3e4271999-05-11Henrik Grubbström (Grubba)  object index_file = open(base_name + ".index", 1);
ebc9881999-05-06Henrik Grubbström (Grubba)  #if constant(set_weak_flag) set_weak_flag(active_objects, 1); #endif /* constant(set_weak_flag) */ /* Initialize the new_entries table. */ array index_st = index_file->stat(); if (!index_st || !sizeof(index_st)) { error(sprintf("stat() failed for quota index file!\n")); } array data_st = data_file->stat(); if (!data_st || !sizeof(data_st)) { error(sprintf("stat() failed for quota data file!\n")); } if (index_st[1] < 0) { error("quota index file isn't a regular file!\n"); } if (data_st[1] < 0) { error("quota data file isn't a regular file!\n"); } if (data_st[1] < index_st[1]) { error("quota data file is shorter than the index file!\n"); } if (index_st[1] & 3) { error("quota index file has odd length!\n"); } if (data_st[1] & 3) { error("quota data file has odd length!\n"); } /* Read the index, and find the last entry in the catalog file. */ int i; array(string) index_str = index_file->read()/4; index = allocate(sizeof(index_str));
a3e4271999-05-11Henrik Grubbström (Grubba)  if (sizeof(index_str) && (sizeof(index_str[-1]) != 4)) {
ebc9881999-05-06Henrik Grubbström (Grubba)  error("Truncated read of the index file!\n"); } foreach(index_str, string offset_str) { int offset; sscanf(offset_str, "%4c", offset); index[i++] = offset; if (offset > next_offset) { next_offset = offset; } }
e9857a1999-05-08Henrik Grubbström (Grubba)  init_index_acc();
ebc9881999-05-06Henrik Grubbström (Grubba)  if (sizeof(index)) { /* Skip past the last entry in the catalog file */ mixed entry = read_entry(next_offset); next_offset = catalog_file->tell(); } if (index_st[1] < data_st[1]) { /* Put everything else in the new_entries_cache */ while (mixed entry = read_entry(next_offset)) { new_entries_cache[entry->name] = next_offset; next_offset = catalog_file->tell(); } /* Clean up the index. */ rebuild_index(); } } }