Use likely()/unlikely() macros to improve branch prediction.

[coloredstderr/coloredstderr.git] / src / coloredstderr.c

diff --git a/src/coloredstderr.c b/src/coloredstderr.c
index 8775541a61e8c6b42d871b0c8cf78628d31f6a0f..72a881fb866ab12e0e92188c58456e4e2979c1a7 100644 (file)
--- a/src/coloredstderr.c
+++ b/src/coloredstderr.c
@@ -51,6 +51,7 @@ static int force_write_to_non_tty;
 
 
 #include "constants.h"
+#include "compiler.h"
 #ifdef DEBUG
 # include "debug.h"
 #endif
@@ -60,38 +61,15 @@ static int force_write_to_non_tty;
 
 
 
-/* Should the "action" handler be invoked for this file descriptor? */
-static int check_handle_fd(int fd) {
-    /* Load state from environment. Only necessary once per process. */
-    if (!initialized) {
-        init_from_environment();
-    }
-
-    /* tracked_fds_find() is most likely faster than calling isatty(),
-     * therefore check if we are tracking this file descriptor first. */
-    if (!tracked_fds_find(fd)) {
-        return 0;
-    }
-
-    /* Never touch anything not going to a terminal - unless we are explicitly
-     * asked to do so. */
-    if (force_write_to_non_tty) {
-        return 1;
-    }
+/* See hookmacros.h for the decision if a function call is colored. */
 
-    int saved_errno = errno;
-    int result = isatty(fd);
-    errno = saved_errno;
-
-    return result;
-}
 
 static void dup_fd(int oldfd, int newfd) {
 #ifdef DEBUG
     debug("%3d -> %3d\t\t\t[%d]\n", oldfd, newfd, getpid());
 #endif
 
-    if (!initialized) {
+    if (unlikely(!initialized)) {
         init_from_environment();
     }
 
@@ -113,7 +91,7 @@ static void close_fd(int fd) {
     debug("%3d ->   .\t\t\t[%d]\n", fd, getpid());
 #endif
 
-    if (!initialized) {
+    if (unlikely(!initialized)) {
         init_from_environment();
     }
 
@@ -147,7 +125,7 @@ inline static void init_pre_post_string(void) {
 static void handle_fd_pre(int fd) {
     int saved_errno = errno;
 
-    if (!pre_string || !post_string) {
+    if (unlikely(!pre_string || !post_string)) {
         init_pre_post_string();
     }
 
@@ -168,7 +146,7 @@ static void handle_fd_post(int fd) {
 static void handle_file_pre(FILE *stream) {
     int saved_errno = errno;
 
-    if (!pre_string || !post_string) {
+    if (unlikely(!pre_string || !post_string)) {
         init_pre_post_string();
     }