cache: use sendfile() instead of a pair of read() + write()

[ps-cgit] / cache.c

diff --git a/cache.c b/cache.c
index fcd461ffe20e29d111e8186f6e924c096f2099e6..9e7eeb0668dab1e9cb9cee0b231c2de1eef134fb 100644 (file)
--- a/cache.c
+++ b/cache.c
@@ -13,6 +13,9 @@
  *
  */
 
+#ifdef HAVE_LINUX_SENDFILE
+#include <sys/sendfile.h>
+#endif
 #include "cgit.h"
 #include "cache.h"
 #include "html.h"
@@ -30,7 +33,6 @@ struct cache_slot {
        const char *lock_name;
        int match;
        struct stat cache_st;
-       struct stat lock_st;
        int bufsize;
        char buf[CACHE_BUFSIZE];
 };
@@ -81,6 +83,23 @@ static int close_slot(struct cache_slot *slot)
 /* Print the content of the active cache slot (but skip the key). */
 static int print_slot(struct cache_slot *slot)
 {
+#ifdef HAVE_LINUX_SENDFILE
+       off_t start_off;
+       int ret;
+
+       start_off = slot->keylen + 1;
+
+       do {
+               ret = sendfile(STDOUT_FILENO, slot->cache_fd, &start_off,
+                               slot->cache_st.st_size - start_off);
+               if (ret < 0) {
+                       if (errno == EAGAIN || errno == EINTR)
+                               continue;
+                       return errno;
+               }
+               return 0;
+       } while (1);
+#else
        ssize_t i, j;
 
        i = lseek(slot->cache_fd, slot->keylen + 1, SEEK_SET);
@@ -97,6 +116,7 @@ static int print_slot(struct cache_slot *slot)
                return errno;
        else
                return 0;
+#endif
 }
 
 /* Check if the slot has expired */
@@ -188,6 +208,10 @@ static int fill_slot(struct cache_slot *slot)
        /* Generate cache content */
        slot->fn();
 
+       /* update stat info */
+       if (fstat(slot->lock_fd, &slot->cache_st))
+               return errno;
+
        /* Restore stdout */
        if (dup2(tmp, STDOUT_FILENO) == -1)
                return errno;