/* Copyright (c) 2013-2018 Dovecot authors, see the included COPYING file */

#include "lib.h"

#include "istream-private.h"

#include "fs-api-private.h"

#include "istream-fs-file.h"

struct fs_file_istream {

  struct istream_private istream;

  struct fs_file *file;

};

static void i_stream_fs_file_close(struct iostream_private *stream,

           bool close_parent ATTR_UNUSED)

{

  struct fs_file_istream *fstream = (struct fs_file_istream *)stream;

  i_stream_destroy(&fstream->istream.parent);

  fs_file_deinit(&fstream->file);

}

static ssize_t i_stream_fs_file_read(struct istream_private *stream)

{

  struct fs_file_istream *fstream = (struct fs_file_istream *)stream;

  struct istream *input;

  if (fstream->istream.parent == NULL) {

    input = fs_read_stream(fstream->file,

      i_stream_get_max_buffer_size(&stream->istream));

    i_stream_init_parent(stream, input);

    i_stream_unref(&input);

  }

  i_stream_seek(stream->parent, stream->parent_start_offset +

          stream->istream.v_offset);

  return i_stream_read_copy_from_parent(&stream->istream);

}

struct istream *

i_stream_create_fs_file(struct fs_file **file, size_t max_buffer_size)

{

  struct fs_file_istream *fstream;

  struct istream *input;

  fstream = i_new(struct fs_file_istream, 1);

  fstream->file = *file;

  fstream->istream.iostream.close = i_stream_fs_file_close;

  fstream->istream.max_buffer_size = max_buffer_size;

  fstream->istream.read = i_stream_fs_file_read;

  fstream->istream.stream_size_passthrough = TRUE;

  fstream->istream.istream.blocking =

    ((*file)->flags & FS_OPEN_FLAG_ASYNC) == 0;

  fstream->istream.istream.seekable =

    ((*file)->flags & FS_OPEN_FLAG_SEEKABLE) != 0;

  input = i_stream_create(&fstream->istream, NULL, -1, 0);

  i_stream_set_name(input, fs_file_path(*file));

  *file = NULL;

  return input;

}