additional readdir refactor cleanup

Differences between readdir and getdents is minimal at best. Leaving code
for now to allow for possible expansion later.

src/fuse_readdir_plus_posix.cpp

@@ -0,0 +1,135 @@
+/*
+  Copyright (c) 2019, Antonio SJ Musumeci <trapexit@spawn.link>
+
+  Permission to use, copy, modify, and/or distribute this software for any
+  purpose with or without fee is hereby granted, provided that the above
+  copyright notice and this permission notice appear in all copies.
+
+  THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
+  WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
+  MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
+  ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
+  WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
+  ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
+  OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
+*/
+
+#define _DEFAULT_SOURCE
+
+#include "branch.hpp"
+#include "errno.hpp"
+#include "fs_base_closedir.hpp"
+#include "fs_base_dirfd.hpp"
+#include "fs_base_opendir.hpp"
+#include "fs_base_readdir.hpp"
+#include "fs_base_fstatat.hpp"
+#include "fs_base_stat.hpp"
+#include "fs_devid.hpp"
+#include "fs_inode.hpp"
+#include "fs_path.hpp"
+#include "hashset.hpp"
+
+#include <fuse.h>
+#include <fuse_dirents.h>
+
+#include <string>
+#include <vector>
+
+#include <dirent.h>
+
+using std::string;
+using std::vector;
+
+namespace l
+{
+  static
+  uint64_t
+  dirent_exact_namelen(const struct dirent *d_)
+  {
+#ifdef _D_EXACT_NAMLEN
+    return _D_EXACT_NAMLEN(d_);
+#elif defined _DIRENT_HAVE_D_NAMLEN
+    return d_->d_namlen;
+#else
+    return strlen(d_->d_name);
+#endif
+  }
+
+  static
+  int
+  readdir_plus(const Branches &branches_,
+               const char     *dirname_,
+               const uint64_t  entry_timeout_,
+               const uint64_t  attr_timeout_,
+               fuse_dirents_t *buf_)
+  {
+    dev_t dev;
+    HashSet names;
+    string basepath;
+    struct stat st;
+    uint64_t namelen;
+    fuse_entry_t entry;
+
+    entry.nodeid           = 0;
+    entry.generation       = 0;
+    entry.entry_valid      = entry_timeout_;
+    entry.attr_valid       = attr_timeout_;
+    entry.entry_valid_nsec = 0;
+    entry.attr_valid_nsec  = 0;
+    for(size_t i = 0, ei = branches_.size(); i != ei; i++)
+      {
+        int rv;
+        int dirfd;
+        DIR *dh;
+
+        basepath = fs::path::make(&branches_[i].path,dirname_);
+
+        dh = fs::opendir(basepath);
+        if(!dh)
+          continue;
+
+        dirfd = fs::dirfd(dh);
+        dev   = fs::devid(dirfd);
+        if(dev == (dev_t)-1)
+          dev = i;
+
+        rv = 0;
+        for(struct dirent *de = fs::readdir(dh); de && !rv; de = fs::readdir(dh))
+          {
+            namelen = l::dirent_exact_namelen(de);
+
+            rv = names.put(de->d_name,namelen);
+            if(rv == 0)
+              continue;
+
+            rv = fs::fstatat_nofollow(dirfd,de->d_name,&st);
+            if(rv == -1)
+              memset(&st,0,sizeof(st));
+
+            de->d_ino = fs::inode::recompute(de->d_ino,dev);
+            st.st_ino = de->d_ino;
+
+            rv = fuse_dirents_add_plus(buf_,de,namelen,&entry,&st);
+            if(rv)
+              return (fs::closedir(dh),-ENOMEM);
+          }
+
+        fs::closedir(dh);
+      }
+
+    return 0;
+  }
+}
+
+namespace FUSE
+{
+  int
+  readdir_plus_posix(const Branches &branches_,
+                     const char     *dirname_,
+                     const uint64_t  entry_timeout_,
+                     const uint64_t  attr_timeout_,
+                     fuse_dirents_t *buf_)
+  {
+    return l::readdir_plus(branches_,dirname_,entry_timeout_,attr_timeout_,buf_);
+  }
+}