"casewindow" data structure that extends the deque (from libpspp) of

[pspp-builds.git] / src / data / casewindow.h

diff --git a/src/data/casewindow.h b/src/data/casewindow.h
new file mode 100644 (file)
index 0000000..a5d03bd
--- /dev/null
+++ b/src/data/casewindow.h
@@ -0,0 +1,51 @@
+/* PSPP - computes sample statistics.
+   Copyright (C) 2007 Free Software Foundation, Inc.
+
+   This program is free software; you can redistribute it and/or
+   modify it under the terms of the GNU General Public License as
+   published by the Free Software Foundation; either version 2 of the
+   License, or (at your option) any later version.
+
+   This program is distributed in the hope that it will be useful, but
+   WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+   General Public License for more details.
+
+   You should have received a copy of the GNU General Public License
+   along with this program; if not, write to the Free Software
+   Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
+   02110-1301, USA. */
+
+/* Sliding window over a set of cases.
+
+   A casewindow is a queue of cases: cases may be added at the
+   head of the queue and deleted from the tail.  A casewindow is
+   initially maintained in memory and then, should it grow too
+   large, is dumped to disk.
+
+   Any case in the casewindow may be accessed, not just the case
+   at the head.  Cases are numbered relative to the tail: the
+   least recently added case is number 0, and so on. */
+
+#ifndef DATA_CASEWINDOW_H
+#define DATA_CASEWINDOW_H 1
+
+#include <stddef.h>
+#include <data/case.h>
+
+struct casewindow *casewindow_create (size_t value_cnt,
+                                      casenumber max_in_core_cases);
+bool casewindow_destroy (struct casewindow *);
+
+void casewindow_push_head (struct casewindow *, struct ccase *);
+void casewindow_pop_tail (struct casewindow *, casenumber cnt);
+bool casewindow_get_case (const struct casewindow *, casenumber case_idx,
+                          struct ccase *);
+size_t casewindow_get_value_cnt (const struct casewindow *);
+casenumber casewindow_get_case_cnt (const struct casewindow *);
+
+bool casewindow_error (const struct casewindow *);
+void casewindow_force_error (struct casewindow *);
+const struct taint *casewindow_get_taint (const struct casewindow *);
+
+#endif /* data/casewindow.h */