improve alignment algorithm

server.c

@@ -743,7 +743,7 @@ int bus_client_process_message(Bus *s, BusClient *client, WireCtx *ctx)
     // message needs to be routed
     // TODO: perform checks here like making sure all method calls have the 'member' field, etc.
 
-    if (!client->unique_name) {
+    if (unlikely(!client->unique_name)) {
         return -1;
     }
 
@@ -760,7 +760,7 @@ int bus_client_process_message(Bus *s, BusClient *client, WireCtx *ctx)
     }
 
 end_nonfatal:
-    if (ctx->byte_cursor != body_end) {
+    if (unlikely(ctx->byte_cursor != body_end)) {
         // The code above did not properly consume the entire message while parsing.
         // This is bad, because we expect the byte_cursor after this function to be
         // exactly at the end of a message. We rely on this invariant for message

wire.c

@@ -4,34 +4,6 @@
 #include "wire.h"
 #include "log.h"
 
-bool wire_align(WireCtx *c, uint32_t alignment)
-{
-    if ((c->byte_cursor % alignment) == 0) {
-        return true;
-    }
-    uint32_t new_cursor = c->byte_cursor + alignment - (c->byte_cursor % alignment);
-    if (unlikely(new_cursor >= c->data_len || new_cursor < c->byte_cursor)) {
-        return false;
-    }
-    c->byte_cursor = new_cursor;
-    return true;
-}
-
-bool wire_write_align(WireCtx *c, uint32_t alignment)
-{
-    if ((c->byte_cursor % alignment) == 0) {
-        return true;
-    }
-    uint32_t new_cursor = c->byte_cursor + alignment - (c->byte_cursor % alignment);
-    if (unlikely(new_cursor >= c->data_len || new_cursor < c->byte_cursor)) {
-        return false;
-    }
-    while (c->byte_cursor < new_cursor) {
-        c->data[c->byte_cursor++] = '\0';
-    }
-    return true;
-}
-
 // SPEC: https://dbus.freedesktop.org/doc/dbus-specification.html#id-1.4.6
 _WIRE_DEF_BYTE_TYPE(i8, int8_t)
 _WIRE_DEF_BYTE_TYPE(u8, uint8_t)

wire.h

@@ -4,6 +4,7 @@
 #include <stdlib.h>
 #include <stdint.h>
 #include <stdbool.h>
+#include "util.h"
 
 
 #define DBUS_PROTOCOL_VERSION 1
@@ -64,6 +65,32 @@ typedef struct {
     char *str;
 } WireMsgBodyString;
 
+static inline bool wire_write_align(WireCtx *c, uint32_t alignment)
+{
+    // Thanks: https://github.com/c-util/c-stdaux/blob/ed5fee49a3ec13fe79f30324b23c73cd41805514/src/c-stdaux-gnuc.h#L431
+    uint32_t new_cursor = ((c->byte_cursor) + (alignment) - 1) & ~((alignment) - 1);
+
+    if (unlikely(new_cursor >= c->data_len || new_cursor < c->byte_cursor)) {
+        return false;
+    }
+    while (c->byte_cursor < new_cursor) {
+        c->data[c->byte_cursor++] = '\0';
+    }
+    return true;
+}
+
+static inline bool wire_align(WireCtx *c, uint32_t alignment)
+{
+    // Thanks: https://github.com/c-util/c-stdaux/blob/ed5fee49a3ec13fe79f30324b23c73cd41805514/src/c-stdaux-gnuc.h#L431
+    uint32_t new_cursor = ((c->byte_cursor) + (alignment) - 1) & ~((alignment) - 1);
+
+    if (unlikely(new_cursor >= c->data_len || new_cursor < c->byte_cursor)) {
+        return false;
+    }
+    c->byte_cursor = new_cursor;
+    return true;
+}
+
 #define _WIRE_DECL_BYTE_TYPE(M_mnemonic, M_type) \
     M_type *wire_get_##M_mnemonic(WireCtx *c); \
     M_type *wire_set_##M_mnemonic(WireCtx *c, M_type val); \