add serializer

[pam_pcsc_cr.git] / serial.c

diff --git a/serial.c b/serial.c
new file mode 100644 (file)
index 0000000..0719746
--- /dev/null
+++ b/serial.c
@@ -0,0 +1,47 @@
+#ifdef HAVE_CONFIG_H
+# include "config.h"
+#endif
+#include <string.h>
+#include "serial.h"
+
+int serial_init(serializer_t *srl, void *buffer, int size)
+{
+       srl->buffer = srl->cursor = buffer;
+       srl->bufsize = size;
+}
+
+int serial_switch(serializer_t *srl, void *buffer, int size)
+{
+       int used = srl->cursor - srl->buffer;
+
+       memcpy(buffer, srl->buffer, used);
+       srl->buffer = buffer;
+       srl->bufsize = size;
+       srl->cursor = buffer + used;
+}
+
+int serial_put(serializer_t *srl, void *item, int size)
+{
+       int left = srl->bufsize - (srl->cursor - srl->buffer);
+       if (left < size + sizeof(short)) return left - sizeof(short);
+       *((short *)srl->cursor) = size;
+       srl->cursor += 2;
+       if (size) memcpy(srl->cursor, item, size);
+       srl->cursor += size;
+       return size;
+}
+
+int serial_get(serializer_t *srl, void *item, int bufsize)
+{
+       short isize = *((short *)srl->cursor);
+       if (isize > bufsize || isize == 0) return isize;
+       srl->cursor += sizeof(short);
+       memcpy(item, srl->cursor, isize);
+       srl->cursor += isize;
+       return isize;
+}
+
+int serial_size(serializer_t *srl)
+{
+       return srl->cursor - srl->buffer;
+}