1 files changed, 92 insertions, 0 deletions
diff --git a/db/hash/page.h b/db/hash/page.h
new file mode 100644
index 0000000000..0fc0d5a3e9
--- /dev/null
+++ b/db/hash/page.h
@@ -0,0 +1,92 @@
+/*-
+ * Copyright (c) 1990, 1993, 1994
+ *	The Regents of the University of California.  All rights reserved.
+ *
+ * This code is derived from software contributed to Berkeley by
+ * Margo Seltzer.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in the
+ *    documentation and/or other materials provided with the distribution.
+ * 3. All advertising materials mentioning features or use of this software
+ *    must display the following acknowledgement:
+ *	This product includes software developed by the University of
+ *	California, Berkeley and its contributors.
+ * 4. Neither the name of the University nor the names of its contributors
+ *    may be used to endorse or promote products derived from this software
+ *    without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
+ * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+ * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
+ * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+ * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
+ * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
+ * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
+ * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
+ * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
+ * SUCH DAMAGE.
+ *
+ *	@(#)page.h	8.2 (Berkeley) 5/31/94
+ */
+
+/*
+ * Definitions for hashing page file format.
+ */
+
+/*
+ * routines dealing with a data page
+ *
+ * page format:
+ *	+------------------------------+
+ * p	| n | keyoff | datoff | keyoff |
+ * 	+------------+--------+--------+
+ *	| datoff | free  |  ptr  | --> |
+ *	+--------+---------------------+
+ *	|	 F R E E A R E A       |
+ *	+--------------+---------------+
+ *	|  <---- - - - | data          |
+ *	+--------+-----+----+----------+
+ *	|  key   | data     | key      |
+ *	+--------+----------+----------+
+ *
+ * Pointer to the free space is always:  p[p[0] + 2]
+ * Amount of free space on the page is:  p[p[0] + 1]
+ */
+
+/*
+ * How many bytes required for this pair?
+ *	2 shorts in the table at the top of the page + room for the
+ *	key and room for the data
+ *
+ * We prohibit entering a pair on a page unless there is also room to append
+ * an overflow page. The reason for this it that you can get in a situation
+ * where a single key/data pair fits on a page, but you can't append an
+ * overflow page and later you'd have to split the key/data and handle like
+ * a big pair.
+ * You might as well do this up front.
+ */
+
+#define	PAIRSIZE(K,D)	(2*sizeof(u_int16_t) + (K)->size + (D)->size)
+#define BIGOVERHEAD	(4*sizeof(u_int16_t))
+#define KEYSIZE(K)	(4*sizeof(u_int16_t) + (K)->size);
+#define OVFLSIZE	(2*sizeof(u_int16_t))
+#define FREESPACE(P)	((P)[(P)[0]+1])
+#define	OFFSET(P)	((P)[(P)[0]+2])
+#define PAIRFITS(P,K,D) \
+	(((P)[2] >= REAL_KEY) && \
+	    (PAIRSIZE((K),(D)) + OVFLSIZE) <= FREESPACE((P)))
+#define PAGE_META(N)	(((N)+3) * sizeof(u_int16_t))
+
+typedef struct {
+	BUFHEAD *newp;
+	BUFHEAD *oldp;
+	BUFHEAD *nextp;
+	u_int16_t next_addr;
+}       SPLIT_RETURN;