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 68ef859dde35bb85915099b1d668bd72ae874b25..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
@@ -60,34 +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 && !isatty(fd)) {
-        return 0;
-    }
+/* See hookmacros.h for the decision if a function call is colored. */
 
-    return 1;
-}
 
 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();
     }
 
@@ -109,7 +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();
     }
 
@@ -140,38 +122,46 @@ inline static void init_pre_post_string(void) {
     post_string_size = strlen(post_string);
 }
 
-static void handle_fd_pre(int fd, int action) {
-    (void)action;
+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();
     }
 
     DLSYM_FUNCTION(real_write, "write");
     real_write(fd, pre_string, pre_string_size);
+
+    errno = saved_errno;
 }
-static void handle_fd_post(int fd, int action) {
-    (void)action;
+static void handle_fd_post(int fd) {
+    int saved_errno = errno;
 
     /* write() already loaded above in handle_fd_pre(). */
     real_write(fd, post_string, post_string_size);
+
+    errno = saved_errno;
 }
 
-static void handle_file_pre(FILE *stream, int action) {
-    (void)action;
+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();
     }
 
     DLSYM_FUNCTION(real_fwrite, "fwrite");
     real_fwrite(pre_string, pre_string_size, 1, stream);
+
+    errno = saved_errno;
 }
-static void handle_file_post(FILE *stream, int action) {
-    (void)action;
+static void handle_file_post(FILE *stream) {
+    int saved_errno = errno;
 
     /* fwrite() already loaded above in handle_file_pre(). */
     real_fwrite(post_string, post_string_size, 1, stream);
+
+    errno = saved_errno;
 }
 
 
@@ -225,8 +215,6 @@ HOOK_FILE2(int, putc_unlocked, stream,
            int, c, FILE *, stream)
 HOOK_FILE1(int, putchar_unlocked, stdout,
            int, c)
-HOOK_FILE1(int, puts_unlocked, stdout,
-           char const *, s)
 
 /* perror(3) */
 HOOK_VOID1(void, perror, STDERR_FILENO,
@@ -313,9 +301,7 @@ int dup(int oldfd) {
 
     newfd = real_dup(oldfd);
     if (newfd != -1) {
-        int saved_errno = errno;
         dup_fd(oldfd, newfd);
-        errno = saved_errno;
     }
 
     return newfd;
@@ -325,9 +311,7 @@ int dup2(int oldfd, int newfd) {
 
     newfd = real_dup2(oldfd, newfd);
     if (newfd != -1) {
-        int saved_errno = errno;
         dup_fd(oldfd, newfd);
-        errno = saved_errno;
     }
 
     return newfd;
@@ -337,9 +321,7 @@ int dup3(int oldfd, int newfd, int flags) {
 
     newfd = real_dup3(oldfd, newfd, flags);
     if (newfd != -1) {
-        int saved_errno = errno;
         dup_fd(oldfd, newfd);
-        errno = saved_errno;
     }
 
     return newfd;
@@ -371,9 +353,7 @@ int fcntl(int fd, int cmd, ...) {
 
     /* We only care about duping fds. */
     if (cmd == F_DUPFD && result != -1) {
-        int saved_errno = errno;
         dup_fd(fd, result);
-        errno = saved_errno;
     }
 
     return result;