mergerfs/src/fuse_readdir_seq_getdents.icpp

#pragma message "using getdents"

#include "dirinfo.hpp"
#include "error.hpp"
#include "fs_close.hpp"
#include "fs_getdents64.hpp"
#include "fs_inode.hpp"
#include "fs_open.hpp"
#include "hashset.hpp"
#include "scope_guard.hpp"

#include "fuse_dirents.hpp"
#include "fuse_msgbuf.hpp"


static
int
_readdir(const Branches::Ptr &branches_,
         const fs::path      &rel_dirpath_,
         fuse_dirents_t      *dirents_)
{
  Err err;
  HashSet names;
  fs::path rel_filepath;
  fs::path abs_dirpath;
  fuse_msgbuf_t *buf;

  fuse_dirents_reset(dirents_);

  buf = msgbuf_alloc();
  DEFER { msgbuf_free(buf); };

  rel_filepath = rel_dirpath_ / "dummy";
  for(const auto &branch : *branches_)
    {
      int fd;

      abs_dirpath = branch.path / rel_dirpath_;

      fd = fs::open_dir_ro(abs_dirpath);
      err = fd;
      if(fd < 0)
        continue;
      DEFER{ fs::close(fd); };

      while(true)
        {
          ssize_t nread;

          nread = fs::getdents64(fd,buf->mem,buf->size);
          if(nread <= 0)
            break;

          for(ssize_t pos = 0; pos < nread;)
            {
              int rv;
              int namelen;
              fs::dirent64 *d = reinterpret_cast<fs::dirent64*>(&buf->mem[pos]);

              pos += d->reclen;

              namelen = d->namelen();

              rv = names.put(d->name,namelen);
              if(rv == 0)
                continue;

              rel_filepath.replace_filename(d->name);

              d->ino = fs::inode::calc(branch.path,
                                       rel_filepath,
                                       DTTOIF(d->type),
                                       d->ino);

              fuse_dirents_add(dirents_,d,namelen);
            }
        }
    }

  return err;
}