+
+bool
+any_reader_close (struct any_reader *any_reader)
+{
+ return any_reader ? any_reader->klass->close (any_reader) : true;
+}
+
+struct casereader *
+any_reader_decode (struct any_reader *any_reader,
+ const char *encoding,
+ struct dictionary **dictp,
+ struct any_read_info *info)
+{
+ const struct any_reader_class *class = any_reader->klass;
+ struct casereader *reader;
+
+ reader = any_reader->klass->decode (any_reader, encoding, dictp, info);
+ if (reader && info)
+ info->klass = class;
+ return reader;
+}
+
+size_t
+any_reader_get_strings (const struct any_reader *any_reader, struct pool *pool,
+ char ***labels, bool **ids, char ***values)
+{
+ return (any_reader->klass->get_strings
+ ? any_reader->klass->get_strings (any_reader, pool, labels, ids,
+ values)
+ : 0);
+}
+
+struct casereader *
+any_reader_open_and_decode (struct file_handle *handle,
+ const char *encoding,
+ struct dictionary **dictp,
+ struct any_read_info *info)
+{
+ struct any_reader *any_reader = any_reader_open (handle);
+ return (any_reader
+ ? any_reader_decode (any_reader, encoding, dictp, info)
+ : NULL);
+}
+\f
+struct dataset_reader
+ {
+ struct any_reader any_reader;
+ struct dictionary *dict;
+ struct casereader *reader;
+ };
+
+/* Opens FH, which must have referent type FH_REF_DATASET, and returns a
+ dataset_reader for it, or a null pointer on failure. Stores a copy of the
+ dictionary for the dataset file into *DICT. The caller takes ownership of
+ the casereader and the dictionary. */
+static struct any_reader *
+dataset_reader_open (struct file_handle *fh)
+{
+ struct dataset_reader *reader;
+ struct dataset *ds;
+
+ /* We don't bother doing fh_lock or fh_ref on the file handle,
+ as there's no advantage in this case, and doing these would
+ require us to keep track of the "struct file_handle" and
+ "struct fh_lock" and undo our work later. */
+ assert (fh_get_referent (fh) == FH_REF_DATASET);
+
+ ds = fh_get_dataset (fh);
+ if (ds == NULL || !dataset_has_source (ds))
+ {
+ msg (SE, _("Cannot read from dataset %s because no dictionary or data "
+ "has been written to it yet."),
+ fh_get_name (fh));
+ return NULL;
+ }
+
+ reader = xmalloc (sizeof *reader);
+ reader->any_reader.klass = &dataset_reader_class;
+ reader->dict = dict_clone (dataset_dict (ds));
+ reader->reader = casereader_clone (dataset_source (ds));
+ return &reader->any_reader;
+}
+
+static struct dataset_reader *
+dataset_reader_cast (const struct any_reader *r_)
+{
+ assert (r_->klass == &dataset_reader_class);
+ return UP_CAST (r_, struct dataset_reader, any_reader);
+}
+
+static bool
+dataset_reader_close (struct any_reader *r_)
+{
+ struct dataset_reader *r = dataset_reader_cast (r_);
+ dict_unref (r->dict);
+ casereader_destroy (r->reader);
+ free (r);
+
+ return true;
+}
+
+static struct casereader *
+dataset_reader_decode (struct any_reader *r_, const char *encoding UNUSED,
+ struct dictionary **dictp, struct any_read_info *info)
+{
+ struct dataset_reader *r = dataset_reader_cast (r_);
+ struct casereader *reader;
+
+ *dictp = r->dict;
+ reader = r->reader;
+ if (info)
+ {
+ memset (info, 0, sizeof *info);
+ info->integer_format = INTEGER_NATIVE;
+ info->float_format = FLOAT_NATIVE_DOUBLE;
+ info->compression = ANY_COMP_NONE;
+ info->case_cnt = casereader_get_case_cnt (reader);
+ }
+ free (r);
+
+ return reader;
+}
+
+static const struct any_reader_class dataset_reader_class =
+ {
+ N_("Dataset"),
+ NULL,
+ dataset_reader_open,
+ dataset_reader_close,
+ dataset_reader_decode,
+ NULL,
+ };