io: os: simplify FlushClient()

Since nobody's passing in extra data here anymore, this function
can be radically simplified now.

Signed-off-by: Enrico Weigelt, metux IT consult <info@metux.net>

os/connection.c

@@ -784,7 +784,7 @@ CloseDownConnection(ClientPtr client)
         CallCallbacks(&FlushCallback, client);
 
     if (oc->output)
-	FlushClient(client, oc, (char *) NULL, 0);
+	FlushClient(client, oc);
     CloseDownFileDescriptor(oc);
     FreeOsBuffers(oc);
     free(client->osPrivate);

os/io.c

@@ -631,7 +631,7 @@ FlushAllOutput(void)
             continue;
         if (!client_is_ready(client)) {
             oc = (OsCommPtr) client->osPrivate;
-            (void) FlushClient(client, oc, (char *) NULL, 0);
+            (void) FlushClient(client, oc);
         } else
             NewOutputPending = TRUE;
     }
@@ -687,7 +687,7 @@ static bool OutputBufferMakeRoom(ClientPtr who, OsCommPtr oc, size_t sz)
         return true;
 
     /* try flushing the buffer */
-    int ret = FlushClient(who, oc, NULL, 0);
+    int ret = FlushClient(who, oc);
     if (ret == -1) /* client was aborted */
         return false;
 
@@ -869,18 +869,12 @@ WriteToClient(ClientPtr who, int count, const void *__buf)
  **********************/
 
 int
-FlushClient(ClientPtr who, OsCommPtr oc, const void *__extraBuf, int extraCount)
+FlushClient(ClientPtr who, OsCommPtr oc)
 {
     ConnectionOutputPtr oco = oc->output;
     XtransConnInfo trans_conn = oc->trans_conn;
-    struct iovec iov[3];
-    static char padBuffer[3];
-    const char *extraBuf = __extraBuf;
-    long written;
-    long padsize;
-    long notWritten;
-    long todo;
 
+    /* if no output buffer, then nothing to do */
     if (!oco)
 	return 0;
 
@@ -892,55 +886,21 @@ FlushClient(ClientPtr who, OsCommPtr oc, const void *__extraBuf, int extraCount)
         return -1;
     }
 
-    written = 0;
-    padsize = padding_for_int32(extraCount);
-    notWritten = oco->count + extraCount + padsize;
+    size_t written = 0;
+    size_t notWritten = oco->count;
+
+    /* do nothing if we haven't anything to write */
     if (!notWritten)
         return 0;
 
     if (FlushCallback)
         CallCallbacks(&FlushCallback, who);
 
-    todo = notWritten;
+    size_t todo = notWritten; /* trying to write that much this time */
     while (notWritten) {
-        long before = written;  /* amount of whole thing written */
-        long remain = todo;     /* amount to try this time, <= notWritten */
-        int i = 0;
-        long len;
-
-        /* You could be very general here and have "in" and "out" iovecs
-         * and write a loop without using a macro, but what the heck.  This
-         * translates to:
-         *
-         *     how much of this piece is new?
-         *     if more new then we are trying this time, clamp
-         *     if nothing new
-         *         then bump down amount already written, for next piece
-         *         else put new stuff in iovec, will need all of next piece
-         *
-         * Note that todo had better be at least 1 or else we'll end up
-         * writing 0 iovecs.
-         */
-#define InsertIOV(pointer, length) \
-	len = (length) - before; \
-	if (len > remain) \
-	    len = remain; \
-	if (len <= 0) { \
-	    before = (-len); \
-	} else { \
-	    iov[i].iov_len = len; \
-	    iov[i].iov_base = (pointer) + before;	\
-	    i++; \
-	    remain -= len; \
-	    before = 0; \
-	}
-
-        InsertIOV((char *) oco->buf, oco->count)
-            InsertIOV((char *) extraBuf, extraCount)
-            InsertIOV(padBuffer, padsize)
-
-            errno = 0;
-        if ((len = _XSERVTransWritev(trans_conn, iov, i)) >= 0) {
+        errno = 0;
+        size_t len = _XSERVTransWrite(trans_conn, (const char*)oco->buf + written, todo);
+        if (len >= 0) {
             written += len;
             notWritten -= len;
             todo = notWritten;
@@ -968,36 +928,14 @@ FlushClient(ClientPtr who, OsCommPtr oc, const void *__extraBuf, int extraCount)
                 oco->count = 0;
             }
 
-            if (notWritten > oco->size) {
-                unsigned char *obuf = NULL;
-
-                if (notWritten + BUFSIZE <= INT_MAX) {
-                    obuf = realloc(oco->buf, notWritten + BUFSIZE);
-                }
-                if (!obuf) {
-                    AbortClient(who);
-                    dixMarkClientException(who);
-                    oco->count = 0;
-                    return -1;
-                }
-                oco->size = notWritten + BUFSIZE;
-                oco->buf = obuf;
-            }
-
-            /* If the amount written extended into the padBuffer, then the
-               difference "extraCount - written" may be less than 0 */
-            if ((len = extraCount - written) > 0)
-                memmove((char *) oco->buf + oco->count,
-                        extraBuf + written, len);
-
-            oco->count = notWritten;    /* this will include the pad */
             ospoll_listen(server_poll, oc->fd, X_NOTIFY_WRITE);
 
             /* return only the amount explicitly requested */
-            return extraCount;
+            return 0;
         }
 #ifdef EMSGSIZE                 /* check for another brain-damaged OS bug */
         else if (errno == EMSGSIZE) {
+            /* making separate try with half of the size */
             todo >>= 1;
         }
 #endif
@@ -1022,7 +960,7 @@ FlushClient(ClientPtr who, OsCommPtr oc, const void *__extraBuf, int extraCount)
         FreeOutputs = oco;
     }
     oc->output = (ConnectionOutputPtr) NULL;
-    return extraCount;          /* return only the amount explicitly requested */
+    return 0;          /* return only the amount explicitly requested */
 }
 
 static ConnectionInputPtr

os/osdep.h

@@ -95,11 +95,7 @@ typedef struct _osComm {
 #define OS_COMM_GRAB_IMPERVIOUS 1
 #define OS_COMM_IGNORED         2
 
-extern int FlushClient(ClientPtr /*who */ ,
-                       OsCommPtr /*oc */ ,
-                       const void * /*extraBuf */ ,
-                       int      /*extraCount */
-    );
+int FlushClient(ClientPtr who, OsCommPtr oc);
 
 extern void FreeOsBuffers(OsCommPtr     /*oc */
     );