initial import of NetBSD tree

1 files changed, 355 insertions, 0 deletions

diff --git a/lib/libc/db/btree/btree.h b/lib/libc/db/btree/btree.h
new file mode 100644
index 00000000000..747ed93638e
--- /dev/null
+++ b/lib/libc/db/btree/btree.h
@@ -0,0 +1,355 @@
+/*	$NetBSD: btree.h,v 1.8 1995/02/27 13:21:08 cgd Exp $	*/
+
+/*-
+ * Copyright (c) 1991, 1993, 1994
+ *	The Regents of the University of California.  All rights reserved.
+ *
+ * This code is derived from software contributed to Berkeley by
+ * Mike Olson.
+ *
+ * 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.
+ *
+ *	@(#)btree.h	8.6 (Berkeley) 5/31/94
+ */
+
+#include <mpool.h>
+
+#define	DEFMINKEYPAGE	(2)		/* Minimum keys per page */
+#define	MINCACHE	(5)		/* Minimum cached pages */
+#define	MINPSIZE	(512)		/* Minimum page size */
+
+/*
+ * Page 0 of a btree file contains a copy of the meta-data.  This page is also
+ * used as an out-of-band page, i.e. page pointers that point to nowhere point
+ * to page 0.  Page 1 is the root of the btree.
+ */
+#define	P_INVALID	 0		/* Invalid tree page number. */
+#define	P_META		 0		/* Tree metadata page number. */
+#define	P_ROOT		 1		/* Tree root page number. */
+
+/*
+ * There are five page layouts in the btree: btree internal pages (BINTERNAL),
+ * btree leaf pages (BLEAF), recno internal pages (RINTERNAL), recno leaf pages
+ * (RLEAF) and overflow pages.  All five page types have a page header (PAGE).
+ * This implementation requires that values within structures NOT be padded.
+ * (ANSI C permits random padding.)  If your compiler pads randomly you'll have
+ * to do some work to get this package to run.
+ */
+typedef struct _page {
+	pgno_t	pgno;			/* this page's page number */
+	pgno_t	prevpg;			/* left sibling */
+	pgno_t	nextpg;			/* right sibling */
+
+#define	P_BINTERNAL	0x01		/* btree internal page */
+#define	P_BLEAF		0x02		/* leaf page */
+#define	P_OVERFLOW	0x04		/* overflow page */
+#define	P_RINTERNAL	0x08		/* recno internal page */
+#define	P_RLEAF		0x10		/* leaf page */
+#define P_TYPE		0x1f		/* type mask */
+#define	P_PRESERVE	0x20		/* never delete this chain of pages */
+	u_int32_t flags;
+
+	indx_t	lower;			/* lower bound of free space on page */
+	indx_t	upper;			/* upper bound of free space on page */
+	indx_t	linp[1];		/* indx_t-aligned VAR. LENGTH DATA */
+} PAGE;
+
+/* First and next index. */
+#define	BTDATAOFF	(sizeof(pgno_t) + sizeof(pgno_t) + sizeof(pgno_t) + \
+			    sizeof(u_int32_t) + sizeof(indx_t) + sizeof(indx_t))
+#define	NEXTINDEX(p)	(((p)->lower - BTDATAOFF) / sizeof(indx_t))
+
+/*
+ * For pages other than overflow pages, there is an array of offsets into the
+ * rest of the page immediately following the page header.  Each offset is to
+ * an item which is unique to the type of page.  The h_lower offset is just
+ * past the last filled-in index.  The h_upper offset is the first item on the
+ * page.  Offsets are from the beginning of the page.
+ *
+ * If an item is too big to store on a single page, a flag is set and the item
+ * is a { page, size } pair such that the page is the first page of an overflow
+ * chain with size bytes of item.  Overflow pages are simply bytes without any
+ * external structure.
+ *
+ * The page number and size fields in the items are pgno_t-aligned so they can
+ * be manipulated without copying.  (This presumes that 32 bit items can be
+ * manipulated on this system.)
+ */
+#define	LALIGN(n) \
+	(((n) + sizeof(pgno_t) - 1) & ~(sizeof(pgno_t) - 1))
+#define	NOVFLSIZE	(sizeof(pgno_t) + sizeof(u_int32_t))
+
+/*
+ * For the btree internal pages, the item is a key.  BINTERNALs are {key, pgno}
+ * pairs, such that the key compares less than or equal to all of the records
+ * on that page.  For a tree without duplicate keys, an internal page with two
+ * consecutive keys, a and b, will have all records greater than or equal to a
+ * and less than b stored on the page associated with a.  Duplicate keys are
+ * somewhat special and can cause duplicate internal and leaf page records and
+ * some minor modifications of the above rule.
+ */
+typedef struct _binternal {
+	u_int32_t ksize;		/* key size */
+	pgno_t	pgno;			/* page number stored on */
+#define	P_BIGDATA	0x01		/* overflow data */
+#define	P_BIGKEY	0x02		/* overflow key */
+	u_char	flags;
+	char	bytes[1];		/* data */
+} BINTERNAL;
+
+/* Get the page's BINTERNAL structure at index indx. */
+#define	GETBINTERNAL(pg, indx) \
+	((BINTERNAL *)((char *)(pg) + (pg)->linp[indx]))
+
+/* Get the number of bytes in the entry. */
+#define NBINTERNAL(len) \
+	LALIGN(sizeof(u_int32_t) + sizeof(pgno_t) + sizeof(u_char) + (len))
+
+/* Copy a BINTERNAL entry to the page. */
+#define	WR_BINTERNAL(p, size, pgno, flags) {				\
+	*(u_int32_t *)p = size;						\
+	p += sizeof(u_int32_t);						\
+	*(pgno_t *)p = pgno;						\
+	p += sizeof(pgno_t);						\
+	*(u_char *)p = flags;						\
+	p += sizeof(u_char);						\
+}
+
+/*
+ * For the recno internal pages, the item is a page number with the number of
+ * keys found on that page and below.
+ */
+typedef struct _rinternal {
+	recno_t	nrecs;			/* number of records */
+	pgno_t	pgno;			/* page number stored below */
+} RINTERNAL;
+
+/* Get the page's RINTERNAL structure at index indx. */
+#define	GETRINTERNAL(pg, indx) \
+	((RINTERNAL *)((char *)(pg) + (pg)->linp[indx]))
+
+/* Get the number of bytes in the entry. */
+#define NRINTERNAL \
+	LALIGN(sizeof(recno_t) + sizeof(pgno_t))
+
+/* Copy a RINTERAL entry to the page. */
+#define	WR_RINTERNAL(p, nrecs, pgno) { \
+	*(recno_t *)p = nrecs; \
+	p += sizeof(recno_t); \
+	*(pgno_t *)p = pgno; \
+}
+
+/* For the btree leaf pages, the item is a key and data pair. */
+typedef struct _bleaf {
+	u_int32_t	ksize;		/* size of key */
+	u_int32_t	dsize;		/* size of data */
+	u_char	flags;			/* P_BIGDATA, P_BIGKEY */
+	char	bytes[1];		/* data */
+} BLEAF;
+
+/* Get the page's BLEAF structure at index indx. */
+#define	GETBLEAF(pg, indx) \
+	((BLEAF *)((char *)(pg) + (pg)->linp[indx]))
+
+/* Get the number of bytes in the entry. */
+#define NBLEAF(p)	NBLEAFDBT((p)->ksize, (p)->dsize)
+
+/* Get the number of bytes in the user's key/data pair. */
+#define NBLEAFDBT(ksize, dsize) \
+	LALIGN(sizeof(u_int32_t) + sizeof(u_int32_t) + sizeof(u_char) + \
+	    (ksize) + (dsize))
+
+/* Copy a BLEAF entry to the page. */
+#define	WR_BLEAF(p, key, data, flags) {					\
+	*(u_int32_t *)p = key->size;					\
+	p += sizeof(u_int32_t);						\
+	*(u_int32_t *)p = data->size;					\
+	p += sizeof(u_int32_t);						\
+	*(u_char *)p = flags;						\
+	p += sizeof(u_char);						\
+	memmove(p, key->data, key->size);				\
+	p += key->size;							\
+	memmove(p, data->data, data->size);				\
+}
+
+/* For the recno leaf pages, the item is a data entry. */
+typedef struct _rleaf {
+	u_int32_t	dsize;		/* size of data */
+	u_char	flags;			/* P_BIGDATA */
+	char	bytes[1];
+} RLEAF;
+
+/* Get the page's RLEAF structure at index indx. */
+#define	GETRLEAF(pg, indx) \
+	((RLEAF *)((char *)(pg) + (pg)->linp[indx]))
+
+/* Get the number of bytes in the entry. */
+#define NRLEAF(p)	NRLEAFDBT((p)->dsize)
+
+/* Get the number of bytes from the user's data. */
+#define	NRLEAFDBT(dsize) \
+	LALIGN(sizeof(u_int32_t) + sizeof(u_char) + (dsize))
+
+/* Copy a RLEAF entry to the page. */
+#define	WR_RLEAF(p, data, flags) {					\
+	*(u_int32_t *)p = data->size;					\
+	p += sizeof(u_int32_t);						\
+	*(u_char *)p = flags;						\
+	p += sizeof(u_char);						\
+	memmove(p, data->data, data->size);				\
+}
+
+/*
+ * A record in the tree is either a pointer to a page and an index in the page
+ * or a page number and an index.  These structures are used as a cursor, stack
+ * entry and search returns as well as to pass records to other routines.
+ *
+ * One comment about searches.  Internal page searches must find the largest
+ * record less than key in the tree so that descents work.  Leaf page searches
+ * must find the smallest record greater than key so that the returned index
+ * is the record's correct position for insertion.
+ *
+ * One comment about cursors.  The cursor key is never removed from the tree,
+ * even if deleted.  This is because it is quite difficult to decide where the
+ * cursor should be when other keys have been inserted/deleted in the tree;
+ * duplicate keys make it impossible.  This scheme does require extra work
+ * though, to make sure that we don't perform an operation on a deleted key.
+ */
+typedef struct _epgno {
+	pgno_t	pgno;			/* the page number */
+	indx_t	index;			/* the index on the page */
+} EPGNO;
+
+typedef struct _epg {
+	PAGE	*page;			/* the (pinned) page */
+	indx_t	 index;			/* the index on the page */
+} EPG;
+
+/*
+ * The metadata of the tree.  The m_nrecs field is used only by the RECNO code.
+ * This is because the btree doesn't really need it and it requires that every
+ * put or delete call modify the metadata.
+ */
+typedef struct _btmeta {
+	u_int32_t	m_magic;	/* magic number */
+	u_int32_t	m_version;	/* version */
+	u_int32_t	m_psize;	/* page size */
+	u_int32_t	m_free;		/* page number of first free page */
+	u_int32_t	m_nrecs;	/* R: number of records */
+#define	SAVEMETA	(B_NODUPS | R_RECNO)
+	u_int32_t	m_flags;	/* bt_flags & SAVEMETA */
+	u_int32_t	m_unused;	/* unused */
+} BTMETA;
+
+/* The in-memory btree/recno data structure. */
+typedef struct _btree {
+	MPOOL	*bt_mp;			/* memory pool cookie */
+
+	DB	*bt_dbp;		/* pointer to enclosing DB */
+
+	EPG	bt_cur;			/* current (pinned) page */
+	PAGE	*bt_pinned;		/* page pinned across calls */
+
+	EPGNO	bt_bcursor;		/* B: btree cursor */
+	recno_t	bt_rcursor;		/* R: recno cursor (1-based) */
+
+#define	BT_POP(t)	(t->bt_sp ? t->bt_stack + --t->bt_sp : NULL)
+#define	BT_CLR(t)	(t->bt_sp = 0)
+	EPGNO	*bt_stack;		/* stack of parent pages */
+	u_int	bt_sp;			/* current stack pointer */
+	u_int	bt_maxstack;		/* largest stack */
+
+	char	*bt_kbuf;		/* key buffer */
+	size_t	bt_kbufsz;		/* key buffer size */
+	char	*bt_dbuf;		/* data buffer */
+	size_t	bt_dbufsz;		/* data buffer size */
+
+	int	bt_fd;			/* tree file descriptor */
+
+	pgno_t	bt_free;		/* next free page */
+	u_int32_t bt_psize;		/* page size */
+	indx_t	bt_ovflsize;		/* cut-off for key/data overflow */
+	int	bt_lorder;		/* byte order */
+					/* sorted order */
+	enum { NOT, BACK, FORWARD } bt_order;
+	EPGNO	bt_last;		/* last insert */
+
+					/* B: key comparison function */
+	int	(*bt_cmp) __P((const DBT *, const DBT *));
+					/* B: prefix comparison function */
+	size_t	(*bt_pfx) __P((const DBT *, const DBT *));
+					/* R: recno input function */
+	int	(*bt_irec) __P((struct _btree *, recno_t));
+
+	FILE	*bt_rfp;		/* R: record FILE pointer */
+	int	bt_rfd;			/* R: record file descriptor */
+
+	caddr_t	bt_cmap;		/* R: current point in mapped space */
+	caddr_t	bt_smap;		/* R: start of mapped space */
+	caddr_t bt_emap;		/* R: end of mapped space */
+	size_t	bt_msize;		/* R: size of mapped region. */
+
+	recno_t	bt_nrecs;		/* R: number of records */
+	size_t	bt_reclen;		/* R: fixed record length */
+	u_char	bt_bval;		/* R: delimiting byte/pad character */
+
+/*
+ * NB:
+ * B_NODUPS and R_RECNO are stored on disk, and may not be changed.
+ */
+#define	B_DELCRSR	0x00001		/* cursor has been deleted */
+#define	B_INMEM		0x00002		/* in-memory tree */
+#define	B_METADIRTY	0x00004		/* need to write metadata */
+#define	B_MODIFIED	0x00008		/* tree modified */
+#define	B_NEEDSWAP	0x00010		/* if byte order requires swapping */
+#define	B_NODUPS	0x00020		/* no duplicate keys permitted */
+#define	B_RDONLY	0x00040		/* read-only tree */
+#define	R_RECNO		0x00080		/* record oriented tree */
+#define	B_SEQINIT	0x00100		/* sequential scan initialized */
+
+#define	R_CLOSEFP	0x00200		/* opened a file pointer */
+#define	R_EOF		0x00400		/* end of input file reached. */
+#define	R_FIXLEN	0x00800		/* fixed length records */
+#define	R_MEMMAPPED	0x01000		/* memory mapped file. */
+#define	R_INMEM		0x02000		/* in-memory file */
+#define	R_MODIFIED	0x04000		/* modified file */
+#define	R_RDONLY	0x08000		/* read-only file */
+
+#define	B_DB_LOCK	0x10000		/* DB_LOCK specified. */
+#define	B_DB_SHMEM	0x20000		/* DB_SHMEM specified. */
+#define	B_DB_TXN	0x40000		/* DB_TXN specified. */
+
+	u_int32_t	bt_flags;	/* btree state */
+} BTREE;
+
+#define	SET(t, f)	((t)->bt_flags |= (f))
+#define	CLR(t, f)	((t)->bt_flags &= ~(f))
+#define	ISSET(t, f)	((t)->bt_flags & (f))
+
+#include "extern.h"