Improvements for BOA

- Allowed write buffers to become very large in asynnet. Thus in order to allow for the transfer
  of large images. tested ub to 2kx2k, 16MB
- Handle lack of space in the write buffer more gracefully: just skip the image

rwpuffer.c

@@ -4,6 +4,11 @@
  * copyright: see file COPYRIGHT
  * 
  * Mark Koennecke, January 2009
+ *
+ * added resizing option and MakeBigRWPuffer in order to support transfer 
+ * of large amounts of image data on few connections
+ *
+ * Mark Koennecke, August 2014
  */
 #include <stdlib.h>
 #include <string.h>
@@ -15,6 +20,7 @@ typedef struct __RWBuffer {
   int length;
   int startPtr;
   int endPtr;
+  int maxSize;
 } RWBuffer;
 /*----------------------------------------------------------------------*/
 prwBuffer MakeRWPuffer(int size)
@@ -32,9 +38,18 @@ prwBuffer MakeRWPuffer(int size)
   self->length = size;
   self->startPtr = 0;
   self->endPtr = 0;
+  self->maxSize = size;
   return self;
 }
-
+/*------------------------------------------------------------------------*/
+prwBuffer MakeBigRWPuffer(int size, int maxSize)
+{
+  prwBuffer result = MakeRWPuffer(size);
+  if(result != NULL){
+    result->maxSize = maxSize;
+  }
+  return result;
+}
 /*------------------------------------------------------------------------*/
 void KillRWBuffer(prwBuffer self)
 {
@@ -46,16 +61,51 @@ void KillRWBuffer(prwBuffer self)
   }
   free(self);
 }
+/*------------------------------------------------------------------------*/
+int CanStoreRWBuffer(prwBuffer self, void *data, int count)
+{
+  int length;
+  char *ptr;
 
+  length = self->endPtr - self->startPtr;
+  if (count + length >= self->length ) {
+    if(self->length < self->maxSize){
+      ptr = calloc(self->maxSize,sizeof(char));
+      if(ptr == NULL) {
+	  return 0;
+      }
+      memcpy(ptr,self->data, length*sizeof(char));
+      free(self->data);
+      self->data = ptr;
+      self->length = self->maxSize;
+    } else {
+      return 0;
+    }
+  }
+  return 1;
+}
 /*------------------------------------------------------------------------*/
 int StoreRWBuffer(prwBuffer self, void *data, int count)
 {
   int length;
+  char *ptr;
 
   length = self->endPtr - self->startPtr;
   if (count + length >= self->length ) {
+    if(self->length < self->maxSize){
+      ptr = calloc(self->maxSize,sizeof(char));
+      if(ptr == NULL) {
 	  printf("HELP: RWBuffer overrun!!!!\n");
-    return 0;
+	  return 0;
+      }
+      memcpy(ptr,self->data, length*sizeof(char));
+      free(self->data);
+      self->data = ptr;
+      self->length = self->maxSize;
+    } else {
+	  printf("HELP: RWBuffer overrun!!!!\n");
+	  return 0;
+    }
   }
   if (count + self->endPtr > self->length) {
     memmove(self->data, self->data + self->startPtr, length);