log: allow users to follow a file

[ps-cgit] / cache.c

diff --git a/cache.c b/cache.c
index fcd461ffe20e29d111e8186f6e924c096f2099e6..cd998127cc23e361cd9f53d9d988754fa5faa93d 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 */
@@ -141,10 +161,23 @@ static int close_lock(struct cache_slot *slot)
  */
 static int lock_slot(struct cache_slot *slot)
 {
-       slot->lock_fd = open(slot->lock_name, O_RDWR | O_CREAT | O_EXCL,
+       struct flock lock = {
+               .l_type = F_WRLCK,
+               .l_whence = SEEK_SET,
+               .l_start = 0,
+               .l_len = 0,
+       };
+
+       slot->lock_fd = open(slot->lock_name, O_RDWR | O_CREAT,
                             S_IRUSR | S_IWUSR);
        if (slot->lock_fd == -1)
                return errno;
+       if (fcntl(slot->lock_fd, F_SETLK, &lock) < 0) {
+               int saved_errno = errno;
+               close(slot->lock_fd);
+               slot->lock_fd = -1;
+               return saved_errno;
+       }
        if (xwrite(slot->lock_fd, slot->key, slot->keylen + 1) < 0)
                return errno;
        return 0;
@@ -188,6 +221,10 @@ 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;
@@ -319,7 +356,7 @@ int cache_process(int size, const char *path, const char *key, int ttl,
        int result;
 
        /* If the cache is disabled, just generate the content */
-       if (size <= 0) {
+       if (size <= 0 || ttl == 0) {
                fn();
                return 0;
        }
@@ -374,7 +411,7 @@ int cache_ls(const char *path)
        DIR *dir;
        struct dirent *ent;
        int err = 0;
-       struct cache_slot slot = { 0 };
+       struct cache_slot slot = { NULL };
        struct strbuf fullname = STRBUF_INIT;
        size_t prefixlen;