Return -1 to indicate buffer overflow. Allow buffer fill level to be read

easily from struct buffer.

1 files changed, 14 insertions, 9 deletions

diff --git a/src/include/buffer.h b/src/include/buffer.h
index 7ed57fa2..b0de39df 100644
--- a/src/include/buffer.h
+++ b/src/include/buffer.h
@@ -4,6 +4,18 @@
 #include "stdint.h"
 
 /*
+ * "start" and "end" denote the real boundaries of the buffer.  "fill"
+ * denotes the offset to the first free block in the buffer.  (If the
+ * buffer is full, "fill" will equal ( end - start ) ).
+ *
+ */
+struct buffer {
+	physaddr_t	start;
+	physaddr_t	end;
+	off_t		fill;
+};
+
+/*
  * Free blocks in the buffer start with a "tail byte".  If non-zero,
  * this byte indicates that the free block is the tail of the buffer,
  * i.e. occupies all the remaining space up to the end of the buffer.
@@ -15,24 +27,17 @@
  * smaller than a struct buffer_free_block.
  *
  */
-
 struct buffer_free_block {
 	char		tail;
 	physaddr_t	next_free;
 	physaddr_t	end;
 } __attribute__ (( packed ));
 
-struct buffer {
-	physaddr_t	start;
-	physaddr_t	end;
-       	physaddr_t	first_free;
-};
-
 /* Functions in buffer.c */
 
 extern void init_buffer ( struct buffer *buffer, physaddr_t start,
 			  size_t len );
-extern off_t fill_buffer ( struct buffer *buffer, void *data,
-			   off_t offset, size_t len );
+extern int fill_buffer ( struct buffer *buffer, void *data,
+			 off_t offset, size_t len );
 
 #endif /* BUFFER_H */