First iteration of mbuf, message buffer api

src/mbuf.c

@@ -0,0 +1,101 @@
+#include <string.h>
+#include <stdlib.h>
+#include "ucore/mbuf.h"
+
+uint8_t *uc_mbuf_put(struct MBuf *mbuf, uint32_t size)
+{
+    uint8_t *data = mbuf->tail;
+    if (uc_mbuf_tailroom(mbuf) < size) {
+        return NULL;
+    }
+
+    mbuf->tail += size;
+
+    return data;
+}
+
+uint8_t *uc_mbuf_push(struct MBuf *mbuf, uint32_t size)
+{
+    if (uc_mbuf_headroom(mbuf) < size) {
+        return NULL;
+    }
+
+    mbuf->head -= size;
+
+    return mbuf->head;
+}
+
+uint8_t *uc_mbuf_pull(struct MBuf *mbuf, uint32_t size)
+{
+    uint8_t *data = mbuf->head;
+    if (uc_mbuf_len(mbuf) < size) {
+        return NULL;
+    }
+
+    mbuf->head += size;
+
+    return data;
+}
+
+
+void uc_mbuf_init(struct MBuf *mbuf, uint8_t *buf, uint32_t len, uint32_t headroom, uint32_t flags)
+{
+    mbuf->bufstart  = buf;
+    mbuf->next      = NULL;
+    mbuf->p1        = mbuf->p2 = mbuf->p3 = mbuf->p4 = NULL;
+    mbuf->cookie    = NULL;
+    mbuf->flags     = flags;
+    mbuf->allocated = len + headroom;
+    mbuf->head      = mbuf->bufstart + headroom;
+    mbuf->tail      = mbuf->head;
+}
+
+struct MBuf *uc_mbuf_new_hr(uint32_t len, uint32_t headroom)
+{
+    struct MBuf *mbuf;
+    uint8_t *buf;
+    
+    mbuf = malloc(sizeof *mbuf);
+    if (mbuf == NULL) 
+        return mbuf;
+
+    buf = malloc(len + headroom);
+    if (buf == NULL) {
+        free(mbuf);
+        return NULL;
+    }
+
+    uc_mbuf_init(mbuf, buf, len, headroom, UC_MBUF_FL_MALLOC);
+
+    return mbuf;
+}
+
+struct MBuf *uc_mbuf_new_inline_hr(uint32_t len, uint32_t headroom)
+{
+    struct MBuf *mbuf;
+    
+    mbuf = malloc(sizeof *mbuf + len + headroom);
+    if (mbuf == NULL) 
+        return mbuf;
+
+    uc_mbuf_init(mbuf, mbuf->inline_data, len, headroom, UC_MBUF_FL_MALLOC_INLINE);
+
+    return mbuf;
+}
+
+void uc_mbuf_free(struct MBuf *mbuf)
+{
+    if (mbuf->flags & (UC_MBUF_FL_MALLOC | UC_MBUF_FL_MALLOC_BUF))
+        free(mbuf->bufstart);
+    
+    if (mbuf->flags & (UC_MBUF_FL_MALLOC | UC_MBUF_FL_MALLOC_INLINE))
+        free(mbuf);
+}
+
+void uc_mbuf_zero(struct MBuf *mbuf)
+{
+    memset(mbuf->bufstart, 0, mbuf->allocated);
+}
+
+#undef UC_INLINE
+