upstream: import some hacked systemd headers

This brings journal-file data structures and byte swapping
helpers I may as well just reuse.

I've had to do some minor messing about to make things workable in
isolation out of the systemd tree without pulling in too much.

I've also added a new HashedObjectHeader type to encompass the
slightly larger common header components of FieldObject and
DataObject to facilitate a generic hash table iterator that can
operate on just loading HashedObjectHeader when nothing more
than the object size is needed for accounting.  Basically the
HashedObjectHeader is ObjectHeader+hash+next_hash_offset.

1 files changed, 41 insertions, 0 deletions

diff --git a/src/upstream/siphash24.h b/src/upstream/siphash24.h
new file mode 100644
index 0000000..7f799ed
--- /dev/null
+++ b/src/upstream/siphash24.h
@@ -0,0 +1,41 @@
+#pragma once
+
+#include <inttypes.h>
+#include <stddef.h>
+#include <stdint.h>
+#include <string.h>
+#include <sys/types.h>
+
+struct siphash {
+        uint64_t v0;
+        uint64_t v1;
+        uint64_t v2;
+        uint64_t v3;
+        uint64_t padding;
+        size_t inlen;
+};
+
+void siphash24_init(struct siphash *state, const uint8_t k[static 16]);
+void siphash24_compress(const void *in, size_t inlen, struct siphash *state);
+#define siphash24_compress_byte(byte, state) siphash24_compress((const uint8_t[]) { (byte) }, 1, (state))
+
+static inline void siphash24_compress_boolean(bool in, struct siphash *state) {
+        uint8_t i = in;
+
+        siphash24_compress(&i, sizeof i, state);
+}
+
+static inline void siphash24_compress_string(const char *in, struct siphash *state) {
+        if (!in)
+                return;
+
+        siphash24_compress(in, strlen(in), state);
+}
+
+uint64_t siphash24_finalize(struct siphash *state);
+
+uint64_t siphash24(const void *in, size_t inlen, const uint8_t k[static 16]);
+
+static inline uint64_t siphash24_string(const char *s, const uint8_t k[static 16]) {
+        return siphash24(s, strlen(s) + 1, k);
+}