Add a function to slice the buffer.

src/buffer.c

@@ -231,6 +231,22 @@ dc_buffer_prepend (dc_buffer_t *buffer, const unsigned char data[], size_t size)
 }
 
 
+int
+dc_buffer_slice (dc_buffer_t *buffer, size_t offset, size_t size)
+{
+	if (buffer == NULL)
+		return 0;
+
+	if (offset + size >= buffer->size)
+		return 0;
+
+	buffer->offset += offset;
+	buffer->size = size;
+
+	return 1;
+}
+
+
 size_t
 dc_buffer_get_size (dc_buffer_t *buffer)
 {

src/buffer.h

@@ -49,6 +49,9 @@ dc_buffer_append (dc_buffer_t *buffer, const unsigned char data[], size_t size);
 int
 dc_buffer_prepend (dc_buffer_t *buffer, const unsigned char data[], size_t size);
 
+int
+dc_buffer_slice (dc_buffer_t *buffer, size_t offset, size_t size);
+
 size_t
 dc_buffer_get_size (dc_buffer_t *buffer);
 

src/libdivecomputer.symbols

@@ -5,6 +5,7 @@ dc_buffer_reserve
 dc_buffer_resize
 dc_buffer_append
 dc_buffer_prepend
+dc_buffer_slice
 dc_buffer_get_size
 dc_buffer_get_data