Add util header

For now, endiannes conversions and getter for unaligned memory.

diff --git a/src/lib/Makefile.am b/src/lib/Makefile.am
index 5368f40..8507888 100644 (file)
--- a/src/lib/Makefile.am
+++ b/src/lib/Makefile.am
@@ -29,3 +29,6 @@ liblightmediascanner_la_SOURCES = \
 
 liblightmediascanner_la_LIBADD = -ldl @SQLITE3_LIBS@ @LTLIBICONV@
 liblightmediascanner_la_LDFLAGS = -version-info @version_info@
+
+# shared sources/headers
+noinst_HEADERS += shared/util.h

diff --git a/src/lib/shared/util.h b/src/lib/shared/util.h
new file mode 100644 (file)
index 0000000..98989a2
--- /dev/null
+++ b/src/lib/shared/util.h
@@ -0,0 +1,80 @@
+/**
+ * Copyright (C) 2013  Intel Corporation. All rights reserved.
+ *
+ * This library is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU Lesser General Public License
+ * as published by the Free Software Foundation; either version 2.1 of
+ * the License, or (at your option) any later version.
+ *
+ * This library is distributed in the hope that it will be useful, but
+ * WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ * Lesser General Public License for more details.
+ *
+ * You should have received a copy of the GNU Lesser General Public
+ * License along with this library; if not, write to the Free Software
+ * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA
+ * 02110-1301 USA
+ *
+ * @author Lucas De Marchi <lucas.demarchi@intel.com>
+ */
+
+#include <byteswap.h>
+#include <endian.h>
+#include <inttypes.h>
+#include <stddef.h>
+
+#define get_unaligned(ptr)                     \
+    ({                                         \
+       struct __attribute__((packed)) {        \
+            typeof(*(ptr)) __v;                 \
+       } *__p = (typeof(__p)) (ptr);           \
+       __p->__v;                               \
+    })
+
+#if __BYTE_ORDER == __LITTLE_ENDIAN
+static inline uint32_t get_le32(const void *ptr)
+{
+       return get_unaligned((const uint32_t *) ptr);
+}
+
+static inline uint32_t get_be32(const void *ptr)
+{
+       return bswap_32(get_unaligned((const uint32_t *) ptr));
+}
+
+static inline uint16_t get_le16(const void *ptr)
+{
+    return get_unaligned((const uint16_t *) ptr);
+}
+
+static inline uint16_t get_be16(const void *ptr)
+{
+    return bswap_16(get_unaligned((const uint16_t *) ptr));
+}
+
+#elif __BYTE_ORDER == __BIG_ENDIAN
+
+static inline uint32_t get_le32(const void *ptr)
+{
+       return bswap_32(get_unaligned((const uint32_t *) ptr));
+}
+
+static inline uint32_t get_be32(const void *ptr)
+{
+       return get_unaligned((const uint32_t *) ptr);
+}
+
+static inline uint16_t get_le16(const void *ptr)
+{
+       return bswap_16(get_unaligned((const uint16_t *) ptr));
+}
+
+static inline uint16_t get_be16(const void *ptr)
+{
+       return get_unaligned((const uint16_t *) ptr);
+}
+
+#else
+#error "Unknown byte order"
+#endif