Merge branch 'singletdb' into single

1 files changed, 0 insertions, 382 deletions

diff --git a/source3/lib/tdb/common/freelist.c b/source3/lib/tdb/common/freelist.c
deleted file mode 100644
index 2f2a4c379b..0000000000
--- a/source3/lib/tdb/common/freelist.c
+++ /dev/null
@@ -1,382 +0,0 @@
- /* 
-   Unix SMB/CIFS implementation.
-
-   trivial database library
-
-   Copyright (C) Andrew Tridgell              1999-2005
-   Copyright (C) Paul `Rusty' Russell		   2000
-   Copyright (C) Jeremy Allison			   2000-2003
-   
-     ** NOTE! The following LGPL license applies to the tdb
-     ** library. This does NOT imply that all of Samba is released
-     ** under the LGPL
-   
-   This library is free software; you can redistribute it and/or
-   modify it under the terms of the GNU Lesser General Public
-   License as published by the Free Software Foundation; either
-   version 3 of the License, or (at your option) any later version.
-
-   This library 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
-   Lesser General Public License for more details.
-
-   You should have received a copy of the GNU Lesser General Public
-   License along with this library; if not, see <http://www.gnu.org/licenses/>.
-*/
-
-#include "tdb_private.h"
-
-/* 'right' merges can involve O(n^2) cost when combined with a
-   traverse, so they are disabled until we find a way to do them in 
-   O(1) time
-*/
-#define USE_RIGHT_MERGES 0
-
-/* read a freelist record and check for simple errors */
-int tdb_rec_free_read(struct tdb_context *tdb, tdb_off_t off, struct list_struct *rec)
-{
-	if (tdb->methods->tdb_read(tdb, off, rec, sizeof(*rec),DOCONV()) == -1)
-		return -1;
-
-	if (rec->magic == TDB_MAGIC) {
-		/* this happens when a app is showdown while deleting a record - we should
-		   not completely fail when this happens */
-		TDB_LOG((tdb, TDB_DEBUG_WARNING, "tdb_rec_free_read non-free magic 0x%x at offset=%d - fixing\n", 
-			 rec->magic, off));
-		rec->magic = TDB_FREE_MAGIC;
-		if (tdb->methods->tdb_write(tdb, off, rec, sizeof(*rec)) == -1)
-			return -1;
-	}
-
-	if (rec->magic != TDB_FREE_MAGIC) {
-		/* Ensure ecode is set for log fn. */
-		tdb->ecode = TDB_ERR_CORRUPT;
-		TDB_LOG((tdb, TDB_DEBUG_WARNING, "tdb_rec_free_read bad magic 0x%x at offset=%d\n", 
-			   rec->magic, off));
-		return TDB_ERRCODE(TDB_ERR_CORRUPT, -1);
-	}
-	if (tdb->methods->tdb_oob(tdb, rec->next+sizeof(*rec), 0) != 0)
-		return -1;
-	return 0;
-}
-
-
-#if USE_RIGHT_MERGES
-/* Remove an element from the freelist.  Must have alloc lock. */
-static int remove_from_freelist(struct tdb_context *tdb, tdb_off_t off, tdb_off_t next)
-{
-	tdb_off_t last_ptr, i;
-
-	/* read in the freelist top */
-	last_ptr = FREELIST_TOP;
-	while (tdb_ofs_read(tdb, last_ptr, &i) != -1 && i != 0) {
-		if (i == off) {
-			/* We've found it! */
-			return tdb_ofs_write(tdb, last_ptr, &next);
-		}
-		/* Follow chain (next offset is at start of record) */
-		last_ptr = i;
-	}
-	TDB_LOG((tdb, TDB_DEBUG_FATAL,"remove_from_freelist: not on list at off=%d\n", off));
-	return TDB_ERRCODE(TDB_ERR_CORRUPT, -1);
-}
-#endif
-
-
-/* update a record tailer (must hold allocation lock) */
-static int update_tailer(struct tdb_context *tdb, tdb_off_t offset,
-			 const struct list_struct *rec)
-{
-	tdb_off_t totalsize;
-
-	/* Offset of tailer from record header */
-	totalsize = sizeof(*rec) + rec->rec_len;
-	return tdb_ofs_write(tdb, offset + totalsize - sizeof(tdb_off_t),
-			 &totalsize);
-}
-
-/* Add an element into the freelist. Merge adjacent records if
-   neccessary. */
-int tdb_free(struct tdb_context *tdb, tdb_off_t offset, struct list_struct *rec)
-{
-	/* Allocation and tailer lock */
-	if (tdb_lock(tdb, -1, F_WRLCK) != 0)
-		return -1;
-
-	/* set an initial tailer, so if we fail we don't leave a bogus record */
-	if (update_tailer(tdb, offset, rec) != 0) {
-		TDB_LOG((tdb, TDB_DEBUG_FATAL, "tdb_free: update_tailer failed!\n"));
-		goto fail;
-	}
-
-#if USE_RIGHT_MERGES
-	/* Look right first (I'm an Australian, dammit) */
-	if (offset + sizeof(*rec) + rec->rec_len + sizeof(*rec) <= tdb->map_size) {
-		tdb_off_t right = offset + sizeof(*rec) + rec->rec_len;
-		struct list_struct r;
-
-		if (tdb->methods->tdb_read(tdb, right, &r, sizeof(r), DOCONV()) == -1) {
-			TDB_LOG((tdb, TDB_DEBUG_FATAL, "tdb_free: right read failed at %u\n", right));
-			goto left;
-		}
-
-		/* If it's free, expand to include it. */
-		if (r.magic == TDB_FREE_MAGIC) {
-			if (remove_from_freelist(tdb, right, r.next) == -1) {
-				TDB_LOG((tdb, TDB_DEBUG_FATAL, "tdb_free: right free failed at %u\n", right));
-				goto left;
-			}
-			rec->rec_len += sizeof(r) + r.rec_len;
-			if (update_tailer(tdb, offset, rec) == -1) {
-				TDB_LOG((tdb, TDB_DEBUG_FATAL, "tdb_free: update_tailer failed at %u\n", offset));
-				goto fail;
-			}
-		}
-	}
-left:
-#endif
-
-	/* Look left */
-	if (offset - sizeof(tdb_off_t) > TDB_DATA_START(tdb->header.hash_size)) {
-		tdb_off_t left = offset - sizeof(tdb_off_t);
-		struct list_struct l;
-		tdb_off_t leftsize;
-		
-		/* Read in tailer and jump back to header */
-		if (tdb_ofs_read(tdb, left, &leftsize) == -1) {
-			TDB_LOG((tdb, TDB_DEBUG_FATAL, "tdb_free: left offset read failed at %u\n", left));
-			goto update;
-		}
-
-		/* it could be uninitialised data */
-		if (leftsize == 0 || leftsize == TDB_PAD_U32) {
-			goto update;
-		}
-
-		left = offset - leftsize;
-
-		if (leftsize > offset ||
-		    left < TDB_DATA_START(tdb->header.hash_size)) {
-			goto update;
-		}
-
-		/* Now read in the left record */
-		if (tdb->methods->tdb_read(tdb, left, &l, sizeof(l), DOCONV()) == -1) {
-			TDB_LOG((tdb, TDB_DEBUG_FATAL, "tdb_free: left read failed at %u (%u)\n", left, leftsize));
-			goto update;
-		}
-
-		/* If it's free, expand to include it. */
-		if (l.magic == TDB_FREE_MAGIC) {
-			/* we now merge the new record into the left record, rather than the other 
-			   way around. This makes the operation O(1) instead of O(n). This change
-			   prevents traverse from being O(n^2) after a lot of deletes */
-			l.rec_len += sizeof(*rec) + rec->rec_len;
-			if (tdb_rec_write(tdb, left, &l) == -1) {
-				TDB_LOG((tdb, TDB_DEBUG_FATAL, "tdb_free: update_left failed at %u\n", left));
-				goto fail;
-			}
-			if (update_tailer(tdb, left, &l) == -1) {
-				TDB_LOG((tdb, TDB_DEBUG_FATAL, "tdb_free: update_tailer failed at %u\n", offset));
-				goto fail;
-			}
-			tdb_unlock(tdb, -1, F_WRLCK);
-			return 0;
-		}
-	}
-
-update:
-
-	/* Now, prepend to free list */
-	rec->magic = TDB_FREE_MAGIC;
-
-	if (tdb_ofs_read(tdb, FREELIST_TOP, &rec->next) == -1 ||
-	    tdb_rec_write(tdb, offset, rec) == -1 ||
-	    tdb_ofs_write(tdb, FREELIST_TOP, &offset) == -1) {
-		TDB_LOG((tdb, TDB_DEBUG_FATAL, "tdb_free record write failed at offset=%d\n", offset));
-		goto fail;
-	}
-
-	/* And we're done. */
-	tdb_unlock(tdb, -1, F_WRLCK);
-	return 0;
-
- fail:
-	tdb_unlock(tdb, -1, F_WRLCK);
-	return -1;
-}
-
-
-
-/* 
-   the core of tdb_allocate - called when we have decided which
-   free list entry to use
-
-   Note that we try to allocate by grabbing data from the end of an existing record,
-   not the beginning. This is so the left merge in a free is more likely to be
-   able to free up the record without fragmentation
- */
-static tdb_off_t tdb_allocate_ofs(struct tdb_context *tdb, 
-				  tdb_len_t length, tdb_off_t rec_ptr,
-				  struct list_struct *rec, tdb_off_t last_ptr)
-{
-#define MIN_REC_SIZE (sizeof(struct list_struct) + sizeof(tdb_off_t) + 8)
-
-	if (rec->rec_len < length + MIN_REC_SIZE) {
-		/* we have to grab the whole record */
-
-		/* unlink it from the previous record */
-		if (tdb_ofs_write(tdb, last_ptr, &rec->next) == -1) {
-			return 0;
-		}
-
-		/* mark it not free */
-		rec->magic = TDB_MAGIC;
-		if (tdb_rec_write(tdb, rec_ptr, rec) == -1) {
-			return 0;
-		}
-		return rec_ptr;
-	}
-
-	/* we're going to just shorten the existing record */
-	rec->rec_len -= (length + sizeof(*rec));
-	if (tdb_rec_write(tdb, rec_ptr, rec) == -1) {
-		return 0;
-	}
-	if (update_tailer(tdb, rec_ptr, rec) == -1) {
-		return 0;
-	}
-
-	/* and setup the new record */
-	rec_ptr += sizeof(*rec) + rec->rec_len;	
-
-	memset(rec, '\0', sizeof(*rec));
-	rec->rec_len = length;
-	rec->magic = TDB_MAGIC;
-
-	if (tdb_rec_write(tdb, rec_ptr, rec) == -1) {
-		return 0;
-	}
-
-	if (update_tailer(tdb, rec_ptr, rec) == -1) {
-		return 0;
-	}
-
-	return rec_ptr;
-}
-
-/* allocate some space from the free list. The offset returned points
-   to a unconnected list_struct within the database with room for at
-   least length bytes of total data
-
-   0 is returned if the space could not be allocated
- */
-tdb_off_t tdb_allocate(struct tdb_context *tdb, tdb_len_t length, struct list_struct *rec)
-{
-	tdb_off_t rec_ptr, last_ptr, newrec_ptr;
-	struct {
-		tdb_off_t rec_ptr, last_ptr;
-		tdb_len_t rec_len;
-	} bestfit;
-	float multiplier = 1.0;
-
-	if (tdb_lock(tdb, -1, F_WRLCK) == -1)
-		return 0;
-
-	/* Extra bytes required for tailer */
-	length += sizeof(tdb_off_t);
-	length = TDB_ALIGN(length, TDB_ALIGNMENT);
-
- again:
-	last_ptr = FREELIST_TOP;
-
-	/* read in the freelist top */
-	if (tdb_ofs_read(tdb, FREELIST_TOP, &rec_ptr) == -1)
-		goto fail;
-
-	bestfit.rec_ptr = 0;
-	bestfit.last_ptr = 0;
-	bestfit.rec_len = 0;
-
-	/* 
-	   this is a best fit allocation strategy. Originally we used
-	   a first fit strategy, but it suffered from massive fragmentation
-	   issues when faced with a slowly increasing record size.
-	 */
-	while (rec_ptr) {
-		if (tdb_rec_free_read(tdb, rec_ptr, rec) == -1) {
-			goto fail;
-		}
-
-		if (rec->rec_len >= length) {
-			if (bestfit.rec_ptr == 0 ||
-			    rec->rec_len < bestfit.rec_len) {
-				bestfit.rec_len = rec->rec_len;
-				bestfit.rec_ptr = rec_ptr;
-				bestfit.last_ptr = last_ptr;
-			}
-		}
-
-		/* move to the next record */
-		last_ptr = rec_ptr;
-		rec_ptr = rec->next;
-
-		/* if we've found a record that is big enough, then
-		   stop searching if its also not too big. The
-		   definition of 'too big' changes as we scan
-		   through */
-		if (bestfit.rec_len > 0 &&
-		    bestfit.rec_len < length * multiplier) {
-			break;
-		}
-		
-		/* this multiplier means we only extremely rarely
-		   search more than 50 or so records. At 50 records we
-		   accept records up to 11 times larger than what we
-		   want */
-		multiplier *= 1.05;
-	}
-
-	if (bestfit.rec_ptr != 0) {
-		if (tdb_rec_free_read(tdb, bestfit.rec_ptr, rec) == -1) {
-			goto fail;
-		}
-
-		newrec_ptr = tdb_allocate_ofs(tdb, length, bestfit.rec_ptr, 
-					      rec, bestfit.last_ptr);
-		tdb_unlock(tdb, -1, F_WRLCK);
-		return newrec_ptr;
-	}
-
-	/* we didn't find enough space. See if we can expand the
-	   database and if we can then try again */
-	if (tdb_expand(tdb, length + sizeof(*rec)) == 0)
-		goto again;
- fail:
-	tdb_unlock(tdb, -1, F_WRLCK);
-	return 0;
-}
-
-
-
-/* 
-   return the size of the freelist - used to decide if we should repack 
-*/
-int tdb_freelist_size(struct tdb_context *tdb)
-{
-	tdb_off_t ptr;
-	int count=0;
-
-	if (tdb_lock(tdb, -1, F_RDLCK) == -1) {
-		return -1;
-	}
-
-	ptr = FREELIST_TOP;
-	while (tdb_ofs_read(tdb, ptr, &ptr) == 0 && ptr != 0) {
-		count++;
-	}
-
-	tdb_unlock(tdb, -1, F_RDLCK);
-	return count;
-}