utils: add helper functions useful for allocating a ring buffer

[project/libubox.git] / utils.h

diff --git a/utils.h b/utils.h
index d00e76b..803150b 100644 (file)
--- a/utils.h
+++ b/utils.h
@@ -23,6 +23,7 @@
 #include <sys/time.h>
 #include <stdint.h>
 #include <stdbool.h>
+#include <unistd.h>
 #include <time.h>
 
 /*
@@ -192,4 +193,23 @@ int b64_decode(const void *src, void *dest, size_t dest_len);
 #define B64_ENCODE_LEN(_len)   ((((_len) + 2) / 3) * 4 + 1)
 #define B64_DECODE_LEN(_len)   (((_len) / 4) * 3 + 1)
 
+static inline unsigned int cbuf_order(unsigned int x)
+{
+       return 32 - __builtin_clz(x - 1);
+}
+
+static inline unsigned long cbuf_size(int order)
+{
+       unsigned long page_size = sysconf(_SC_PAGESIZE);
+       unsigned long ret = 1ULL << order;
+
+       if (ret < page_size)
+               ret = page_size;
+
+       return ret;
+}
+
+void *cbuf_alloc(unsigned int order);
+void cbuf_free(void *ptr, unsigned int order);
+
 #endif