First iteration of mbuf, message buffer api

include/ucore/mbuf.h

@@ -0,0 +1,78 @@
+#ifndef UC_MBUF_H_
+#define UC_MBUF_H_
+#include <stdint.h>
+#include <stddef.h>
+
+#ifdef __GNUC__
+#   define UC_INLINE inline __attribute__((always_inline))
+#else
+#   define UC_INLINE inline
+#endif
+
+enum UC_MBUF_FLAGS {
+    UC_MBUF_FL_MALLOC        = 0x0001, //MBuf and MBuf->bufstart are seperatly malloc'd
+    UC_MBUF_FL_MALLOC_BUF    = 0x0001, //MBuf is not malloc'd. MBuf->bufstart is malloc'd
+    UC_MBUF_FL_MALLOC_INLINE = 0x0002, //MBuf is one big malloc. Can't be resized
+    UC_MBUF_FL_STATIC        = 0x0004, //MBuf and MBuf->bustart is user controlled. Can't be resized
+};
+
+struct MBuf {
+    struct MBuf *next;
+    uint8_t *p1;
+    uint8_t *p2;
+    uint8_t *p3;
+    uint8_t *p4;
+    void *cookie;
+    uint32_t flags;
+    uint32_t allocated;
+    uint8_t *bufstart;
+    uint8_t *head;
+    uint8_t *tail;
+    uint8_t inline_data[0];
+};
+
+/* Conventions:
+ * push - prepend data to the buffer (in the head room part)
+ * pull - remove data from the beginning of the message.
+ * put  - Add data to the buffer.
+ */
+struct MBuf *uc_mbuf_new_hr(uint32_t len, uint32_t headroom);
+#define uc_mbuf_new(len) uc_mbuf_new_hr((len), 0)
+
+struct MBuf *uc_mbuf_new_inline_hr(uint32_t len, uint32_t headroom);
+#define uc_mbuf_new_inline(len) uc_mbuf_new_inline_hr((len), 0)
+
+void uc_mbuf_free(struct MBuf *mbuf);
+struct MBuf *uc_mbuf_copy(struct MBuf *mbuf);
+
+void uc_mbuf_init(struct MBuf *mbuf, uint8_t *buf, uint32_t len, uint32_t headroom, uint32_t flags);
+void uc_mbuf_zero(struct MBuf *mbuf);
+void uc_mbuf_reset(struct MBuf *mbuf);
+
+static UC_INLINE uint32_t uc_mbuf_len(struct MBuf *mbuf)
+{
+    return (uint32_t)(mbuf->tail - mbuf->head);
+}
+
+static UC_INLINE uint32_t uc_mbuf_tailroom(struct MBuf *mbuf)
+{
+    return mbuf->allocated - (uint32_t)(mbuf->tail - mbuf->bufstart);
+}
+
+static inline uint32_t uc_mbuf_headroom(struct MBuf *mbuf)
+{
+    return (uint32_t)(mbuf->head - mbuf->bufstart);
+}
+
+uint8_t *uc_mbuf_put(struct MBuf *mbuf, uint32_t size);
+
+uint8_t *uc_mbuf_push(struct MBuf *mbuf, uint32_t size);
+
+uint8_t *uc_mbuf_pull(struct MBuf *mbuf, uint32_t size);
+
+struct MBuf *uc_uc_mbuf_new_hr(uint32_t len, uint32_t headroom);
+struct MBuf *uc_uc_mbuf_new_inline_hr(uint32_t len, uint32_t headroom);
+
+#undef UC_INLINE
+
+#endif