r11620@catbus: nickm | 2007-02-01 13:06:27 -0500

Call stat() slightly less often; use fstat() when possible.


svn:r9472

ChangeLog

@@ -62,6 +62,7 @@ Changes in version 0.1.2.7-alpha - 2007-??-??
       unstable ones.
     - Handle TTL values correctly on reverse DNS lookups.
     - Stop using the reserved ac_cv namespace in our configure script.
+    - Call stat() slightly less often; use fstat() when possible.
 
   o Major features:
     - Weight directory requests by advertised bandwidth. Now we can

src/common/compat.c

@@ -241,14 +241,14 @@ tor_munmap_file(tor_mmap_t *handle)
 tor_mmap_t *
 tor_mmap_file(const char *filename)
 {
-  size_t size;
+  struct stat st;
-  char *res = read_file_to_str(filename, 1, &size);
+  char *res = read_file_to_str(filename, 1, &st);
   tor_mmap_t *handle;
   if (! res)
     return NULL;
   handle = tor_malloc_zero(sizeof(tor_mmap_t));
   handle->data = res;
-  handle->size = size;
+  handle->size = st.st_size;
   return handle;
 }
 void

src/common/util.c

@@ -1375,30 +1375,27 @@ append_bytes_to_file(const char *fname, const char *str, size_t len,
  * be truncated.
  */
 char *
-read_file_to_str(const char *filename, int bin, size_t *size_out)
+read_file_to_str(const char *filename, int bin, struct stat *stat_out)
 {
   int fd; /* router file */
   struct stat statbuf;
-  char *string, *f;
+  char *string;
   int r;
 
   tor_assert(filename);
 
-  f = tor_strdup(filename);
-  clean_name_for_stat(f);
-  r = stat(f, &statbuf);
-  tor_free(f);
-  if (r < 0) {
-    log_info(LD_FS,"Could not stat \"%s\".",filename);
-    return NULL;
-  }
-
   fd = open(filename,O_RDONLY|(bin?O_BINARY:O_TEXT),0);
   if (fd<0) {
     log_warn(LD_FS,"Could not open \"%s\".",filename);
     return NULL;
   }
 
+  if (fstat(fd, &statbuf)<0) {
+    close(fd);
+    log_info(LD_FS,"Could not fstat \"%s\".",filename);
+    return NULL;
+  }
+
   if ((uint64_t)(statbuf.st_size)+1 > SIZE_T_MAX)
     return NULL;
 
@@ -1414,26 +1411,31 @@ read_file_to_str(const char *filename, int bin, size_t *size_out)
   }
   string[r] = '\0'; /* NUL-terminate the result. */
 
-  if (bin && r != statbuf.st_size) {
-    /* If we're in binary mode, then we'd better have an exact match for
-     * size.  Otherwise, win32 encoding may throw us off, and that's okay. */
-    log_warn(LD_FS,"Could read only %d of %ld bytes of file \"%s\".",
-             r, (long)statbuf.st_size,filename);
-    tor_free(string);
-    close(fd);
-    return NULL;
-  }
 #ifdef MS_WINDOWS
   if (!bin && strchr(string, '\r')) {
     log_debug(LD_FS, "We didn't convert CRLF to LF as well as we hoped "
               "when reading %s. Coping.",
               filename);
     tor_strstrip(string, "\r");
+    r = strlen(string);
   }
+  if (!bin) {
+    statbuf.st_size = (size_t) r;
+  } else
 #endif
+    if (r != statbuf.st_size) {
+      /* Unless we're using text mode on win32, we'd better have an exact
+       * match for size. */
+      log_warn(LD_FS,"Could read only %d of %ld bytes of file \"%s\".",
+               r, (long)statbuf.st_size,filename);
+      tor_free(string);
       close(fd);
-  if (size_out)
+      return NULL;
-    *size_out = (size_t) r;
+    }
+  close(fd);
+  if (stat_out) {
+    memcpy(stat_out, &statbuf, sizeof(struct stat));
+  }
 
   return string;
 }

src/common/util.h

@@ -182,7 +182,8 @@ int write_chunks_to_file(const char *fname, const struct smartlist_t *chunks,
 int append_bytes_to_file(const char *fname, const char *str, size_t len,
                          int bin);
 
-char *read_file_to_str(const char *filename, int bin, size_t *size_out)
+struct stat;
+char *read_file_to_str(const char *filename, int bin, struct stat *stat_out)
   ATTR_MALLOC;
 char *parse_line_from_str(char *line, char **key_out, char **value_out);
 char *expand_filename(const char *filename);

src/or/dns.c

@@ -1529,8 +1529,8 @@ configure_nameservers(int force)
   evdns_set_log_fn(evdns_log_cb);
   if (conf_fname) {
     if (stat(conf_fname, &st)) {
-      log_warn(LD_EXIT, "Unable to stat resolver configuration in '%s'",
+      log_warn(LD_EXIT, "Unable to stat resolver configuration in '%s': %s",
-               conf_fname);
+               conf_fname, strerror(errno));
       return -1;
     }
     if (!force && resolv_conf_fname && !strcmp(conf_fname,resolv_conf_fname)

src/or/routerlist.c

@@ -118,8 +118,8 @@ int
 router_reload_networkstatus(void)
 {
   char filename[512];
-  struct stat st;
   smartlist_t *entries;
+  struct stat st;
   char *s;
   tor_assert(get_options()->DataDirectory);
   if (!networkstatus_list)
@@ -138,9 +138,8 @@ router_reload_networkstatus(void)
       }
       tor_snprintf(filename,sizeof(filename),"%s/cached-status/%s",
                    get_options()->DataDirectory, fn);
-      s = read_file_to_str(filename, 0, NULL);
+      s = read_file_to_str(filename, 0, &st);
       if (s) {
-        stat(filename, &st);
         if (router_set_networkstatus(s, st.st_mtime, NS_FROM_CACHE, NULL)<0) {
           log_warn(LD_FS, "Couldn't load networkstatus from \"%s\"",filename);
         }
@@ -353,7 +352,6 @@ router_reload_router_list(void)
   or_options_t *options = get_options();
   size_t fname_len = strlen(options->DataDirectory)+32;
   char *fname = tor_malloc(fname_len), *contents;
-  struct stat st;
 
   if (!routerlist)
     router_get_routerlist(); /* mallocs and inits it in place */
@@ -376,7 +374,6 @@ router_reload_router_list(void)
                options->DataDirectory);
   contents = read_file_to_str(fname, 1, NULL);
   if (contents) {
-    stat(fname, &st);
     router_load_routers_from_string(contents,
                                     SAVED_IN_JOURNAL, NULL);
     tor_free(contents);