API cleanups, offset by bit.

[babeltrace.git] / include / babeltrace / types.h

diff --git a/include/babeltrace/types.h b/include/babeltrace/types.h
index 417bb691ca6020453905c7ecac64596955d00759..862624084371ecfcf1d1692f7fe10762136ed5b5 100644 (file)
--- a/include/babeltrace/types.h
+++ b/include/babeltrace/types.h
@@ -24,6 +24,61 @@
  */
 
 #include <babeltrace/format.h>
+#include <babeltrace/align.h>
+#include <string.h>
+
+/*
+ * Always update stream_pos with move_pos and init_pos.
+ */
+struct stream_pos {
+       unsigned char *base;    /* Base address */
+       size_t offset;          /* Offset from base, in bits */
+       int dummy;              /* Dummy position, for length calculation */
+};
+
+static inline
+void init_pos(struct stream_pos *pos, unsigned char *base)
+{
+       pos->base = base;       /* initial base, page-aligned */
+       pos->offset = 0;
+       pos->dummy = false;
+}
+
+/*
+ * move_pos - move position of a relative bit offset
+ *
+ * TODO: allow larger files by updating base too.
+ */
+static inline
+void move_pos(struct stream_pos *pos, size_t offset)
+{
+       pos->offset = pos->offset + offset;
+}
+
+/*
+ * align_pos - align position on a bit offset (> 0)
+ *
+ * TODO: allow larger files by updating base too.
+ */
+static inline
+void align_pos(struct stream_pos *pos, size_t offset)
+{
+       pos->offset += offset_align(pos->offset, offset);
+}
+
+static inline
+void copy_pos(struct stream_pos *dest, struct stream_pos *src)
+{
+       memcpy(dest, src, sizeof(struct stream_pos));
+}
+
+static inline
+unsigned char *get_pos_addr(struct stream_pos *pos)
+{
+       /* Only makes sense to get the address after aligning on CHAR_BIT */
+       assert(!(pos->alignment % CHAR_BIT));
+       return pos->base + (pos->offset / CHAR_BIT);
+}
 
 struct type_class {
        GQuark name;            /* type name */
@@ -32,8 +87,8 @@ struct type_class {
         * Type copy function. Knows how to find the child type_class from the
         * parent type_class.
         */
-       size_t (*copy)(unsigned char *dest, const struct format *fdest, 
-                      const unsigned char *src, const struct format *fsrc,
+       size_t (*copy)(struct stream_pos *dest, const struct format *fdest, 
+                      struct stream_pos *src, const struct format *fsrc,
                       const struct type_class *type_class);
        void (*free)(struct type_class *type_class);
 };
@@ -45,15 +100,19 @@ struct type_class_integer {
        int signedness;
 };
 
+/*
+ * Because we address in bits, bitfields end up being exactly the same as
+ * integers, except that their read/write functions must be able to deal with
+ * read/write non aligned on CHAR_BIT.
+ */
 struct type_class_bitfield {
        struct type_class_integer p;
-       size_t start_offset;    /* offset from base address, in bits */
 };
 
 struct type_class_float {
        struct type_class p;
-       size_t mantissa_len;
-       size_t exp_len;
+       struct bitfield_class *mantissa;
+       struct bitfield_class *exp;
        int byte_order;
        /* TODO: we might want to express more info about NaN, +inf and -inf */
 };
@@ -68,6 +127,10 @@ struct type_class_enum {
        struct enum_table table;
 };
 
+struct type_class_string {
+       struct type_class p;
+};
+
 struct type_class_struct {
        struct type_class p;
        /* TODO */