Cleaned up type namespace, mapping now works, introduced anonymous mapping, made init/deinit code, time now works.... Glue code and init code still missing

trackerlogic.c

@@ -1,15 +1,25 @@
 // THIS REALLY BELONGS INTO A HEADER FILE
 //
 //
+#include <stdlib.h>
 #include <string.h>
 #include <stdio.h>
 #include <fcntl.h>
 #include <sys/types.h>
 #include <sys/mman.h>
-
-typedef unsigned char ot_hash[20];
-typedef unsigned char ot_ip[ 4/*0*/ ];
-typedef unsigned long ot_time;
+#include <unistd.h>
+#include <time.h>
+
+/* Should be called BYTE, WORD, DWORD - but some OSs already have that and there's no #iftypedef */
+/* They mark memory used as data instead of integer or human readable string -
+   they should be cast before used as integer/text */
+typedef unsigned char  ot_byte;
+typedef unsigned short ot_word;
+typedef unsigned long  ot_dword;
+
+typedef unsigned long  ot_time;
+typedef ot_byte        ot_hash[20];
+typedef ot_byte        ot_ip[ 4/*0*/ ];
 // tunables
 const unsigned long OT_TIMEOUT          = 2700;
 const unsigned long OT_HUGE_FILESIZE    = 1024*1024*256; // Thats 256MB per file, enough for 204800 peers of 128 bytes
@@ -21,28 +31,30 @@ const unsigned long OT_HUGE_FILESIZE    = 1024*1024*256; // Thats 256MB per file
 #define FORMAT_FIXED_STRING  sprintf
 #define FORMAT_FORMAT_STRING sprintf
 #define BINARY_FIND          binary_search
+#define NOW                  time(NULL)
 
-typedef struct {
+typedef struct ot_peer {
 #ifndef OT_COMPACT_ONLY
-  ot_hash         id;
-  ot_hash         key;
+  ot_hash id;
+  ot_hash key;
 #endif
-  ot_ip           ip;
-  unsigned short  port;
-  ot_time         death;
-  unsigned char   flags;
-} ot_peer;
-unsigned char PEER_FLAG_SEEDING   = 0x80;
-unsigned char PEER_IP_LENGTH_MASK = 0x3f;
+  ot_ip   ip;
+  ot_word port;
+  ot_time death;
+  ot_byte flags;
+} *ot_peer;
+ot_byte PEER_FLAG_SEEDING   = 0x80;
+ot_byte PEER_IP_LENGTH_MASK = 0x3f;
 
 typedef struct {
-  ot_hash         hash;
-  ot_peer        *peer_list;
-  unsigned long   peer_count;
-  unsigned long   seed_count;
-} ot_torrent;
+  ot_hash       hash;
+  ot_peer       peer_list;
+  unsigned long peer_count;
+  unsigned long seed_count;
+} *ot_torrent;
 
 void *map_file( char *file_name );
+void  unmap_file( char *file_name, void *map, unsigned long real_size );
 
 // This behaves quite like bsearch but allows to find
 // the insertion point for inserts after unsuccessful searches
@@ -60,28 +72,33 @@ int compare_ip_port( const void *peer1, const void *peer2 ) { return memcmp( pee
 //
 // END OF STUFF THAT BELONGS INTO A HEADER FILE
 
-ot_torrent *torrents_pointer = 0;
 unsigned long torrents_count = 0;
-unsigned char *scratchspace;
+ot_torrent    torrents_list  = 0;
+ot_byte       *scratch_space = 0;
+
+// Converter function from memory to human readable hex strings
+// * definitely not thread safe!!!
+//
+char ths[1+2*20];char *to_hex(ot_byte*s){char*m="0123456789ABCDEF";char*e=ths+40;char*t=ths;while(t<e){*t++=m[*s>>4];*t++=m[*s++&15];}*t=0;return ths;}
 
-ot_torrent *add_peer_to_torrent( ot_hash hash, ot_peer *peer ) {
-  ot_torrent *torrent;
-  ot_peer    *peer_dest;
-  int exactmatch;
+ot_torrent add_peer_to_torrent( ot_hash hash, ot_peer peer ) {
+  ot_torrent torrent;
+  ot_peer    peer_dest;
+  int        exactmatch;
 
-  torrent = BINARY_FIND( hash, torrents_pointer, torrents_count, sizeof( ot_torrent ), compare_hash, &exactmatch );
+  torrent = BINARY_FIND( hash, torrents_list, torrents_count, sizeof( *torrent ), compare_hash, &exactmatch );
   if( !exactmatch ) {
     // Assume, OS will provide us with space, after all, this is file backed
-    MEMMOVE( torrent + 1, torrent, ( torrents_pointer + torrents_count ) - torrent );
+    MEMMOVE( torrent + 1, torrent, ( torrents_list + torrents_count ) - torrent );
 
     // Create a new torrent entry, then
     MEMMOVE( &torrent->hash, hash, sizeof( ot_hash ) );
-    torrent->peer_list  = map_file( hash );
+    torrent->peer_list  = map_file( to_hex( hash ) );
     torrent->peer_count = 0;
     torrent->seed_count = 0;
   }
 
-  peer_dest = BINARY_FIND( peer, torrent->peer_list, torrent->peer_count, sizeof( ot_peer ), compare_ip_port, &exactmatch );
+  peer_dest = BINARY_FIND( peer, torrent->peer_list, torrent->peer_count, sizeof( *peer_dest ), compare_ip_port, &exactmatch );
   if( exactmatch ) {
     // If peer was a seeder but isn't anymore, decrease seeder count
     if( ( peer_dest->flags & PEER_FLAG_SEEDING ) && !( peer->flags & PEER_FLAG_SEEDING ) )
@@ -100,18 +117,18 @@ ot_torrent *add_peer_to_torrent( ot_hash hash, ot_peer *peer ) {
   }
 
   // Set new time out time
-  peer_dest->death = now() + OT_TIMEOUT;
+  peer_dest->death = NOW + OT_TIMEOUT;
 
   return torrent;
 }
 
-#define SETINVALID( i )   (scratchspace[index] = 3);
-#define SETSELECTED( i )  (scratchspace[index] = 1);
-#define TESTSELECTED( i ) (scratchspace[index] == 1 )
-#define TESTSET( i )      (scratchspace[index])
+#define SETINVALID( i )   (scratch_space[index] = 3);
+#define SETSELECTED( i )  (scratch_space[index] = 1);
+#define TESTSELECTED( i ) (scratch_space[index] == 1 )
+#define TESTSET( i )      (scratch_space[index])
 #define RANDOM            random()
 
-inline int TESTVALIDPEER( ot_peer *p ) { return p->death > now(); }
+inline int TESTVALIDPEER( ot_peer p ) { return p->death > NOW; }
 
 // Compiles a list of random peers for a torrent
 // * scratch space keeps track of death or already selected peers
@@ -122,14 +139,14 @@ inline int TESTVALIDPEER( ot_peer *p ) { return p->death > now(); }
 // * it is not guaranteed to see all peers, so no assumptions on active seeders/peers may be done
 // * since compact format cannot handle v6 addresses, it must be enabled by OT_COMPACT_ONLY
 //
-void return_peers_for_torrent( ot_torrent *torrent, unsigned long amount, char *reply ) {
-  register ot_peer *peer_base = torrent->peer_list;
-  unsigned long     peer_count = torrent->peer_count;
-  unsigned long     selected_count = 0, invalid_count = 0;
-  unsigned long     index = 0;
+void return_peers_for_torrent( ot_torrent torrent, unsigned long amount, char *reply ) {
+  register ot_peer peer_base = torrent->peer_list;
+  unsigned long    peer_count = torrent->peer_count;
+  unsigned long    selected_count = 0, invalid_count = 0;
+  unsigned long    index = 0;
 
   // optimize later ;)
-  BZERO( scratchspace, peer_count );
+  BZERO( scratch_space, peer_count );
 
   while( ( selected_count < amount ) && ( selected_count + invalid_count < peer_count ) ) {
     // skip to first non-flagged peer
@@ -150,11 +167,11 @@ void return_peers_for_torrent( ot_torrent *torrent, unsigned long amount, char *
 #ifndef OT_COMPACT_ONLY
   reply += FORMAT_FIXED_STRING( reply, "d5:peersl" );
 #else
-  reply += FORMAT_FORMAT_STRING( reply, "d5:peers%i:",6*selected_count );
+  reply += FORMAT_FORMAT_STRING( reply, "d5:peers%li:",6*selected_count );
 #endif
 
   while( selected_count-- ) {
-    ot_peer *peer;
+    ot_peer peer;
     while( !TESTSELECTED( index ) ) ++index;
     peer = peer_base + index;
 #ifdef OT_COMPACT_ONLY
@@ -181,11 +198,11 @@ void return_peers_for_torrent( ot_torrent *torrent, unsigned long amount, char *
 // * is rather expansive
 // * if this fails, torrent file is invalid, should add flag
 //
-void heal_torrent( ot_torrent *torrent ) {
-  unsigned long index = 0, base = 0, end, seed_count = 0;
+void heal_torrent( ot_torrent torrent ) {
+  unsigned long index = 0, base = 0, end, seed_count = 0, now = NOW;
 
   // Initialize base to first dead peer.
-  while( ( base < torrent->peer_count ) && torrent->peer_list[base].death <= now() ) {
+  while( ( base < torrent->peer_count ) && torrent->peer_list[base].death <= now ) {
     seed_count += ( torrent->peer_list[base].flags & PEER_FLAG_SEEDING ) ? 1 : 0;
     base++;
   }
@@ -199,7 +216,7 @@ void heal_torrent( ot_torrent *torrent ) {
 
   while( 1 ) {
     // Let index search for next living peer
-    while( ( index < torrent->peer_count ) && torrent->peer_list[index].death > now() ) index++;
+    while( ( index < torrent->peer_count ) && torrent->peer_list[index].death > now ) index++;
 
     // No further living peers found - base is our new peer count
     if( index == torrent->peer_count ) {
@@ -211,25 +228,32 @@ void heal_torrent( ot_torrent *torrent ) {
     end = index + 1;
 
     // Let end search for next dead peer (end of living peers)
-    while( ( end < torrent->peer_count ) && torrent->peer_list[end].death <= now() ) {
+    while( ( end < torrent->peer_count ) && torrent->peer_list[end].death <= now ) {
       seed_count += ( torrent->peer_list[end].flags & PEER_FLAG_SEEDING ) ? 1 : 0;
       end++;
     }
 
     // We either hit a dead peer or the end of our peers
     // In both cases: move block towards base
-    MEMMOVE( torrent->peer_list + base, torrent->peer_list + index, ( end - index ) * sizeof( ot_peer ) );
+    MEMMOVE( torrent->peer_list + base, torrent->peer_list + index, ( end - index ) * sizeof( struct ot_peer ) );
     base += end - index;
 
     index = end;
   }
 }
 
+void dispose_torrent( ot_torrent torrent ) {
+  unmap_file( "", torrent->peer_list, 0 );
+  unlink( to_hex( torrent->hash ) );
+  MEMMOVE( torrent, torrent + 1, ( torrents_list + torrents_count ) - ( torrent + 1 ) );
+  torrents_count--;
+}
+
 void *binary_search( const void *key, const void *base,
                      unsigned long member_count, const unsigned long member_size,
                      int (*compar) (const void *, const void *),
                      int *exactmatch ) {
-  unsigned char *lookat = ((unsigned char*)base) + member_size * (member_count >> 1);
+  ot_byte *lookat = ((ot_byte*)base) + member_size * (member_count >> 1);
   *exactmatch = 1;
 
   while( member_count ) {
@@ -240,7 +264,7 @@ void *binary_search( const void *key, const void *base,
       --member_count;
     }
     member_count >>= 1;
-    lookat = ((unsigned char*)base) + member_size * (member_count >> 1);
+    lookat = ((ot_byte*)base) + member_size * (member_count >> 1);
   }
   *exactmatch = 0;
   return (void*)lookat;
@@ -248,26 +272,44 @@ void *binary_search( const void *key, const void *base,
 }
 
 // This function maps a "huge" file into process space
+// * no name will aqcuire anonymous growable memory
+// * memory will not be "freed" from systems vm if once used, until unmap_file
 // * I guess, we should be checking for more errors...
+//
 void *map_file( char *file_name ) {
   char *map;
-  int file_desc=open(file_name,O_RDWR|O_CREAT|O_NDELAY,0644);
-
-  if( file_desc < 0) return 0;
-
-  map=mmap(0,OT_HUGE_FILESIZE,PROT_READ|PROT_WRITE,MAP_SHARED,file_desc,0);
-  close(file_desc);
+  if( file_name ) {
+    int file_desc=open(file_name,O_RDWR|O_CREAT|O_NDELAY,0644);
+    if( file_desc < 0) return 0;
+    map=mmap(0,OT_HUGE_FILESIZE,PROT_READ|PROT_WRITE,MAP_SHARED,file_desc,0);
+    close(file_desc);
+  } else
+    map=mmap(0,OT_HUGE_FILESIZE,PROT_READ|PROT_WRITE,MAP_ANON,-1,0);
 
   return (map == (char*)-1) ? 0 : map;
 }
 
+void unmap_file( char *file_name, void *map, unsigned long real_size ) {
+  munmap( map, OT_HUGE_FILESIZE );
+  if( file_name)
+    truncate( file_name, real_size );
+}
+
 int init_logic( ) {
-  unlink( "./opentracker_map_index.idx" );
-  torrents_pointer = map_file( "./opentracker_map_index.idx" );
+  scratch_space    = map_file( "" );
+  torrents_list    = map_file( "" );
   torrents_count   = 0;
-  scratchspace     = map_file( "./scratchspace" );
+
+  // Scan directory for filenames in the form [0-9A-F]{20}
+  // ...
+
+  return 0;
 }
 
 void deinit_logic( ) {
-  unmap_file( torrents_pointer );
+  // For all torrents... blablabla
+  while( torrents_count-- )
+    unmap_file( to_hex(torrents_list[torrents_count].hash), torrents_list[torrents_count].peer_list, torrents_list[torrents_count].peer_count * sizeof(struct ot_peer) );
+  unmap_file( "", torrents_list, 0 );
+  unmap_file( "", scratch_space, 0 );
 }