dlls/dplayx/name_server.c

   1 /* DPLAYX.DLL name server implementation
   2  *
   3  * Copyright 2000 - Peter Hunnisett
   4  *
   5  * <presently under construction - contact hunnise@nortelnetworks.com>
   6  *
   7  */
   8
   9 /* NOTE: Methods with the NS_ prefix are name server methods */
  10
  11 #include "winbase.h"
  12 #include "debugtools.h"
  13
  14 #include "dplayx_global.h"
  15 #include "name_server.h"
  16
  17 /* FIXME: Need to aquire the interface semaphore before didlling data */
  18
  19 DEFAULT_DEBUG_CHANNEL(dplay);
  20
  21 /* NS specific structures */
  22 typedef struct tagNSCacheData
  23 {
  24   struct tagNSCacheData* next;
  25
  26   LPDPSESSIONDESC2 data;
  27
  28 } NSCacheData, *lpNSCacheData;
  29
  30 typedef struct tagNSCache
  31 {
  32   lpNSCacheData present; /* keep track of what is to be looked at */
  33   lpNSCacheData first;
  34 } NSCache, *lpNSCache;
  35
  36 /* Local Prototypes */
  37 static void NS_InvalidateSessionCache( lpNSCache lpCache );
  38
  39
  40 /* Name Server functions
  41  * ---------------------
  42  */
  43 void NS_SetLocalComputerAsNameServer( LPCDPSESSIONDESC2 lpsd )
  44 {
  45   DPLAYX_SetLocalSession( lpsd );
  46 }
  47
  48 /* This function is responsible for sending a request for all other known
  49    nameservers to send us what sessions they have registered locally
  50  */
  51 void NS_SendSessionRequestBroadcast( LPVOID lpNSInfo )
  52 {
  53   UINT index = 0;
  54   lpNSCache lpCache = (lpNSCache)lpNSInfo;
  55   LPDPSESSIONDESC2 lpTmp = NULL;
  56
  57   /* Invalidate the session cache for the interface */
  58   NS_InvalidateSessionCache( lpCache );
  59
  60   /* Add the local known sessions to the cache */
  61   if( ( lpTmp = DPLAYX_CopyAndAllocateLocalSession( &index ) ) != NULL )
  62   {
  63     lpCache->first = (lpNSCacheData)HeapAlloc( GetProcessHeap(),
  64                                                HEAP_ZERO_MEMORY,
  65                                                sizeof( *(lpCache->first) ) );
  66     lpCache->first->data = lpTmp;
  67     lpCache->first->next = NULL;
  68     lpCache->present = lpCache->first;
  69
  70     while( ( lpTmp = DPLAYX_CopyAndAllocateLocalSession( &index ) ) != NULL )
  71     {
  72       lpCache->present->next = (lpNSCacheData)HeapAlloc( GetProcessHeap(),
  73                                                          HEAP_ZERO_MEMORY,
  74                                                          sizeof( *(lpCache->present) ) );
  75       lpCache->present = lpCache->present->next;
  76       lpCache->present->data = lpTmp;
  77       lpCache->present->next = NULL;
  78     }
  79
  80     lpCache->present = lpCache->first;
  81   }
  82
  83   /* Send out requests for matching sessions to all other known computers */
  84   FIXME( ": no remote requests sent\n" );
  85   /* FIXME - how to handle responses to messages anyways? */
  86 }
  87
  88 /* Render all data in a session cache invalid */
  89 static void NS_InvalidateSessionCache( lpNSCache lpCache )
  90 {
  91   if( lpCache == NULL )
  92   {
  93     ERR( ": invalidate non existant cache\n" );
  94     return;
  95   }
  96
  97   /* Remove everything from the cache */
  98   while( lpCache->first )
  99   {
 100     lpCache->present = lpCache->first;
 101     lpCache->first = lpCache->first->next;
 102     HeapFree( GetProcessHeap(), 0, lpCache->present );
 103   }
 104
 105   /* NULL out the cache pointers */
 106   lpCache->present = NULL;
 107   lpCache->first   = NULL;
 108 }
 109
 110 /* Create and initialize a session cache */
 111 BOOL NS_InitializeSessionCache( LPVOID* lplpNSInfo )
 112 {
 113   lpNSCache lpCache = (lpNSCache)HeapAlloc( GetProcessHeap(),
 114                                             HEAP_ZERO_MEMORY,
 115                                             sizeof( *lpCache ) );
 116
 117   *lplpNSInfo = lpCache;
 118
 119   if( lpCache == NULL )
 120   {
 121     return FALSE;
 122   }
 123
 124   lpCache->first = lpCache->present = NULL;
 125
 126   return TRUE;
 127 }
 128
 129 /* Delete a session cache */
 130 void NS_DeleteSessionCache( LPVOID lpNSInfo )
 131 {
 132   NS_InvalidateSessionCache( (lpNSCache)lpNSInfo );
 133 }
 134
 135 /* Reinitialize the present pointer for this cache */
 136 void NS_ResetSessionEnumeration( LPVOID lpNSInfo )
 137 {
 138
 139   ((lpNSCache)lpNSInfo)->present = ((lpNSCache)lpNSInfo)->first;
 140 }
 141
 142 LPDPSESSIONDESC2 NS_WalkSessions( LPVOID lpNSInfo )
 143 {
 144   LPDPSESSIONDESC2 lpSessionDesc;
 145   lpNSCache lpCache = (lpNSCache)lpNSInfo;
 146
 147   /* Test for end of the list */
 148   if( lpCache->present == NULL )
 149   {
 150     return NULL;
 151   }
 152
 153   lpSessionDesc = lpCache->present->data;
 154
 155   /* Advance tracking pointer */
 156   lpCache->present = lpCache->present->next;
 157
 158   return lpSessionDesc;
 159 }