/*-
 * See the file LICENSE for redistribution information.
 *
 * Copyright (c) 1996,2008 Oracle.  All rights reserved.
 */
/*
 * Copyright (c) 1990, 1993, 1994
 *	Margo Seltzer.  All rights reserved.
 */
/*
 * 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. 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.
 *
 * $Id: hash_open.c,v 12.33 2008/01/30 12:18:22 mjc Exp $
 */

#include "db_config.h"

#include "db_int.h"
#include "dbinc/crypto.h"
#include "dbinc/db_page.h"
#include "dbinc/hash.h"
#include "dbinc/log.h"
#include "dbinc/lock.h"
#include "dbinc/mp.h"
#include "dbinc/btree.h"
#include "dbinc/fop.h"

static db_pgno_t __ham_init_meta __P((DB *, HMETA *, db_pgno_t, DB_LSN *));

/*
 * __ham_open --
 *
 * PUBLIC: int __ham_open __P((DB *, DB_THREAD_INFO *,
 * PUBLIC:     DB_TXN *, const char * name, db_pgno_t, u_int32_t));
 */
int
__ham_open(dbp, ip, txn, name, base_pgno, flags)
	DB *dbp;
	DB_THREAD_INFO *ip;
	DB_TXN *txn;
	const char *name;
	db_pgno_t base_pgno;
	u_int32_t flags;
{
	DBC *dbc;
	ENV *env;
	HASH *hashp;
	HASH_CURSOR *hcp;
	int ret, t_ret;

	env = dbp->env;
	dbc = NULL;

	/*
	 * Get a cursor.  If DB_CREATE is specified, we may be creating
	 * pages, and to do that safely in CDB we need a write cursor.
	 * In STD_LOCKING mode, we'll synchronize using the meta page
	 * lock instead.
	 */
	if ((ret = __db_cursor(dbp, ip,
	    txn, &dbc, LF_ISSET(DB_CREATE) && CDB_LOCKING(env) ?
	    DB_WRITECURSOR : 0)) != 0)
		return (ret);

	hcp = (HASH_CURSOR *)dbc->internal;
	hashp = dbp->h_internal;
	hashp->meta_pgno = base_pgno;
	if ((ret = __ham_get_meta(dbc)) != 0)
		goto err;

	/* Initialize the hdr structure.  */
	if (hcp->hdr->dbmeta.magic == DB_HASHMAGIC) {
		/* File exists, verify the data in the header. */
		if (hashp->h_hash == NULL)
			hashp->h_hash = hcp->hdr->dbmeta.version < 5
			? __ham_func4 : __ham_func5;
		hashp->h_nelem = hcp->hdr->nelem;
		if (F_ISSET(&hcp->hdr->dbmeta, DB_HASH_DUP))
			F_SET(dbp, DB_AM_DUP);
		if (F_ISSET(&hcp->hdr->dbmeta, DB_HASH_DUPSORT))
			F_SET(dbp, DB_AM_DUPSORT);
		if (F_ISSET(&hcp->hdr->dbmeta, DB_HASH_SUBDB))
			F_SET(dbp, DB_AM_SUBDB);
		if (PGNO(hcp->hdr) == PGNO_BASE_MD &&
		     !F_ISSET(dbp, DB_AM_RECOVER))
			__memp_set_last_pgno(dbp->mpf,
			    hcp->hdr->dbmeta.last_pgno);
	} else if (!IS_RECOVERING(env) && !F_ISSET(dbp, DB_AM_RECOVER)) {
		__db_errx(env,
		    "%s: Invalid hash meta page %lu", name, (u_long)base_pgno);
		ret = EINVAL;
	}

	/* Release the meta data page */
	if ((t_ret = __ham_release_meta(dbc)) != 0 && ret == 0)
		ret = t_ret;
err:	if ((t_ret  = __dbc_close(dbc)) != 0 && ret == 0)
		ret = t_ret;

	return (ret);
}

/*
 * __ham_metachk --
 *
 * PUBLIC: int __ham_metachk __P((DB *, const char *, HMETA *));
 */
int
__ham_metachk(dbp, name, hashm)
	DB *dbp;
	const char *name;
	HMETA *hashm;
{
	ENV *env;
	u_int32_t vers;
	int ret;

	env = dbp->env;

	/*
	 * At this point, all we know is that the magic number is for a Hash.
	 * Check the version, the database may be out of date.
	 */
	vers = hashm->dbmeta.version;
	if (F_ISSET(dbp, DB_AM_SWAP))
		M_32_SWAP(vers);
	switch (vers) {
	case 4:
	case 5:
	case 6:
		__db_errx(env,
		    "%s: hash version %lu requires a version upgrade",
		    name, (u_long)vers);
		return (DB_OLD_VERSION);
	case 7:
	case 8:
	case 9:
		break;
	default:
		__db_errx(env,
		    "%s: unsupported hash version: %lu", name, (u_long)vers);
		return (EINVAL);
	}

	/* Swap the page if we need to. */
	if (F_ISSET(dbp, DB_AM_SWAP) &&
	    (ret = __ham_mswap(env, (PAGE *)hashm)) != 0)
		return (ret);

	/* Check the type. */
	if (dbp->type != DB_HASH && dbp->type != DB_UNKNOWN)
		return (EINVAL);
	dbp->type = DB_HASH;
	DB_ILLEGAL_METHOD(dbp, DB_OK_HASH);

	/*
	 * Check application info against metadata info, and set info, flags,
	 * and type based on metadata info.
	 */
	if ((ret = __db_fchk(env,
	    "DB->open", hashm->dbmeta.flags,
	    DB_HASH_DUP | DB_HASH_SUBDB | DB_HASH_DUPSORT)) != 0)
		return (ret);

	if (F_ISSET(&hashm->dbmeta, DB_HASH_DUP))
		F_SET(dbp, DB_AM_DUP);
	else
		if (F_ISSET(dbp, DB_AM_DUP)) {
			__db_errx(env,
		"%s: DB_DUP specified to open method but not set in database",
			    name);
			return (EINVAL);
		}

	if (F_ISSET(&hashm->dbmeta, DB_HASH_SUBDB))
		F_SET(dbp, DB_AM_SUBDB);
	else
		if (F_ISSET(dbp, DB_AM_SUBDB)) {
			__db_errx(env,
	    "%s: multiple databases specified but not supported in file",
			name);
			return (EINVAL);
		}

	if (F_ISSET(&hashm->dbmeta, DB_HASH_DUPSORT)) {
		if (dbp->dup_compare == NULL)
			dbp->dup_compare = __bam_defcmp;
	} else
		if (dbp->dup_compare != NULL) {
			__db_errx(env,
		"%s: duplicate sort function specified but not set in database",
			    name);
			return (EINVAL);
		}

	/* Set the page size. */
	dbp->pgsize = hashm->dbmeta.pagesize;

	/* Copy the file's ID. */
	memcpy(dbp->fileid, hashm->dbmeta.uid, DB_FILE_ID_LEN);

	return (0);
}

/*
 * __ham_init_meta --
 *
 * Initialize a hash meta-data page.  We assume that the meta-data page is
 * contiguous with the initial buckets that we create.  If that turns out
 * to be false, we'll fix it up later.  Return the initial number of buckets
 * allocated.
 */
static db_pgno_t
__ham_init_meta(dbp, meta, pgno, lsnp)
	DB *dbp;
	HMETA *meta;
	db_pgno_t pgno;
	DB_LSN *lsnp;
{
	ENV *env;
	HASH *hashp;
	db_pgno_t nbuckets;
	u_int i, l2;

	env = dbp->env;
	hashp = dbp->h_internal;

	if (hashp->h_hash == NULL)
		hashp->h_hash = DB_HASHVERSION < 5 ? __ham_func4 : __ham_func5;

	if (hashp->h_nelem != 0 && hashp->h_ffactor != 0) {
		hashp->h_nelem = (hashp->h_nelem - 1) / hashp->h_ffactor + 1;
		l2 = __db_log2(hashp->h_nelem > 2 ? hashp->h_nelem : 2);
	} else
		l2 = 1;
	nbuckets = (db_pgno_t)(1 << l2);

	memset(meta, 0, sizeof(HMETA));
	meta->dbmeta.lsn = *lsnp;
	meta->dbmeta.pgno = pgno;
	meta->dbmeta.magic = DB_HASHMAGIC;
	meta->dbmeta.version = DB_HASHVERSION;
	meta->dbmeta.pagesize = dbp->pgsize;
	if (F_ISSET(dbp, DB_AM_CHKSUM))
		FLD_SET(meta->dbmeta.metaflags, DBMETA_CHKSUM);
	if (F_ISSET(dbp, DB_AM_ENCRYPT)) {
		meta->dbmeta.encrypt_alg = env->crypto_handle->alg;
		DB_ASSERT(env, meta->dbmeta.encrypt_alg != 0);
		meta->crypto_magic = meta->dbmeta.magic;
	}
	meta->dbmeta.type = P_HASHMETA;
	meta->dbmeta.free = PGNO_INVALID;
	meta->dbmeta.last_pgno = pgno;
	meta->max_bucket = nbuckets - 1;
	meta->high_mask = nbuckets - 1;
	meta->low_mask = (nbuckets >> 1) - 1;
	meta->ffactor = hashp->h_ffactor;
	meta->nelem = hashp->h_nelem;
	meta->h_charkey = hashp->h_hash(dbp, CHARKEY, sizeof(CHARKEY));
	memcpy(meta->dbmeta.uid, dbp->fileid, DB_FILE_ID_LEN);

	if (F_ISSET(dbp, DB_AM_DUP))
		F_SET(&meta->dbmeta, DB_HASH_DUP);
	if (F_ISSET(dbp, DB_AM_SUBDB))
		F_SET(&meta->dbmeta, DB_HASH_SUBDB);
	if (dbp->dup_compare != NULL)
		F_SET(&meta->dbmeta, DB_HASH_DUPSORT);

	/*
	 * Create the first and second buckets pages so that we have the
	 * page numbers for them and we can store that page number in the
	 * meta-data header (spares[0]).
	 */
	meta->spares[0] = pgno + 1;

	/* Fill in the last fields of the meta data page. */
	for (i = 1; i <= l2; i++)
		meta->spares[i] = meta->spares[0];
	for (; i < NCACHED; i++)
		meta->spares[i] = PGNO_INVALID;

	return (nbuckets);
}

/*
 * __ham_new_file --
 *	Create the necessary pages to begin a new database file.  If name
 * is NULL, then this is an unnamed file, the mpf has been set in the dbp
 * and we simply create the pages using mpool.  In this case, we don't log
 * because we never have to redo an unnamed create and the undo simply
 * frees resources.
 *
 * This code appears more complex than it is because of the two cases (named
 * and unnamed).  The way to read the code is that for each page being created,
 * there are three parts: 1) a "get page" chunk (which either uses malloc'd
 * memory or calls __memp_fget), 2) the initialization, and 3) the "put page"
 * chunk which either does a fop write or an __memp_fput.
 *
 * PUBLIC: int __ham_new_file __P((DB *,
 * PUBLIC:      DB_THREAD_INFO *, DB_TXN *, DB_FH *, const char *));
 */
int
__ham_new_file(dbp, ip, txn, fhp, name)
	DB *dbp;
	DB_THREAD_INFO *ip;
	DB_TXN *txn;
	DB_FH *fhp;
	const char *name;
{
	DBT pdbt;
	DB_LSN lsn;
	DB_MPOOLFILE *mpf;
	DB_PGINFO pginfo;
	ENV *env;
	HMETA *meta;
	PAGE *page;
	int ret;
	db_pgno_t lpgno;
	void *buf;

	env = dbp->env;
	mpf = dbp->mpf;
	meta = NULL;
	page = NULL;
	buf = NULL;

	if (F_ISSET(dbp, DB_AM_INMEM)) {
		/* Build meta-data page. */
		lpgno = PGNO_BASE_MD;
		if ((ret = __memp_fget(mpf, &lpgno, ip, txn,
		    DB_MPOOL_CREATE | DB_MPOOL_DIRTY, &meta)) != 0)
			return (ret);
		LSN_NOT_LOGGED(lsn);
		lpgno = __ham_init_meta(dbp, meta, PGNO_BASE_MD, &lsn);
		meta->dbmeta.last_pgno = lpgno;
		if ((ret = __db_log_page(dbp,
		    txn, &lsn, meta->dbmeta.pgno, (PAGE *)meta)) != 0)
			goto err;
		ret = __memp_fput(mpf, ip, meta, dbp->priority);
		meta = NULL;
		if (ret != 0)
			goto err;

		/* Allocate the final hash bucket. */
		if ((ret = __memp_fget(mpf, &lpgno, ip, txn,
		    DB_MPOOL_CREATE, &page)) != 0)
			goto err;
		P_INIT(page,
		    dbp->pgsize, lpgno, PGNO_INVALID, PGNO_INVALID, 0, P_HASH);
		LSN_NOT_LOGGED(page->lsn);
		if ((ret =
		    __db_log_page(dbp, txn, &page->lsn, lpgno, page)) != 0)
			goto err;
		ret = __memp_fput(mpf, ip, page, dbp->priority);
		page = NULL;
		if (ret != 0)
			goto err;
	} else {
		memset(&pdbt, 0, sizeof(pdbt));

		/* Build meta-data page. */
		pginfo.db_pagesize = dbp->pgsize;
		pginfo.type = dbp->type;
		pginfo.flags =
		    F_ISSET(dbp, (DB_AM_CHKSUM | DB_AM_ENCRYPT | DB_AM_SWAP));
		pdbt.data = &pginfo;
		pdbt.size = sizeof(pginfo);
		if ((ret = __os_calloc(dbp->env, 1, dbp->pgsize, &buf)) != 0)
			return (ret);
		meta = (HMETA *)buf;
		LSN_NOT_LOGGED(lsn);
		lpgno = __ham_init_meta(dbp, meta, PGNO_BASE_MD, &lsn);
		meta->dbmeta.last_pgno = lpgno;
		if ((ret =
		    __db_pgout(env->dbenv, PGNO_BASE_MD, meta, &pdbt)) != 0)
			goto err;
		if ((ret = __fop_write(env, txn, name, DB_APP_DATA, fhp,
		    dbp->pgsize, 0, 0, buf, dbp->pgsize, 1, F_ISSET(
		    dbp, DB_AM_NOT_DURABLE) ? DB_LOG_NOT_DURABLE : 0)) != 0)
			goto err;
		meta = NULL;

		/* Allocate the final hash bucket. */
#ifdef DIAGNOSTIC
		memset(buf, 0, dbp->pgsize);
#endif
		page = (PAGE *)buf;
		P_INIT(page,
		    dbp->pgsize, lpgno, PGNO_INVALID, PGNO_INVALID, 0, P_HASH);
		LSN_NOT_LOGGED(page->lsn);
		if ((ret = __db_pgout(env->dbenv, lpgno, buf, &pdbt)) != 0)
			goto err;
		if ((ret = __fop_write(env, txn, name, DB_APP_DATA, fhp,
		    dbp->pgsize, lpgno, 0, buf, dbp->pgsize, 1, F_ISSET(
		    dbp, DB_AM_NOT_DURABLE) ? DB_LOG_NOT_DURABLE : 0)) != 0)
			goto err;
		page = NULL;
	}

err:	if (buf != NULL)
		__os_free(env, buf);
	else {
		if (meta != NULL)
			(void)__memp_fput(mpf, ip, meta, dbp->priority);
		if (page != NULL)
			(void)__memp_fput(mpf, ip, page, dbp->priority);
	}
	return (ret);
}

/*
 * __ham_new_subdb --
 *	Create the necessary pages to begin a new subdatabase.
 *
 * PUBLIC: int __ham_new_subdb __P((DB *, DB *, DB_THREAD_INFO *, DB_TXN *));
 */
int
__ham_new_subdb(mdbp, dbp, ip, txn)
	DB *mdbp, *dbp;
	DB_THREAD_INFO *ip;
	DB_TXN *txn;
{
	DBC *dbc;
	DBMETA *mmeta;
	DB_LOCK metalock, mmlock;
	DB_LSN lsn;
	DB_MPOOLFILE *mpf;
	ENV *env;
	HMETA *meta;
	PAGE *h;
	int i, ret, t_ret;
	db_pgno_t lpgno, mpgno;

	env = mdbp->env;
	mpf = mdbp->mpf;
	dbc = NULL;
	meta = NULL;
	mmeta = NULL;
	LOCK_INIT(metalock);
	LOCK_INIT(mmlock);

	if ((ret = __db_cursor(mdbp, ip, txn,
	    &dbc, CDB_LOCKING(env) ?  DB_WRITECURSOR : 0)) != 0)
		return (ret);

	/* Get and lock the new meta data page. */
	if ((ret = __db_lget(dbc,
	    0, dbp->meta_pgno, DB_LOCK_WRITE, 0, &metalock)) != 0)
		goto err;
	if ((ret = __memp_fget(mpf, &dbp->meta_pgno, ip, dbc->txn,
	    DB_MPOOL_CREATE, &meta)) != 0)
		goto err;

	/* Initialize the new meta-data page. */
	lsn = meta->dbmeta.lsn;
	lpgno = __ham_init_meta(dbp, meta, dbp->meta_pgno, &lsn);

	/*
	 * We are about to allocate a set of contiguous buckets (lpgno
	 * worth).  We need to get the master meta-data page to figure
	 * out where these pages are and to allocate them.  So, lock and
	 * get the master meta data page.
	 */
	mpgno = PGNO_BASE_MD;
	if ((ret = __db_lget(dbc, 0, mpgno, DB_LOCK_WRITE, 0, &mmlock)) != 0)
		goto err;
	if ((ret = __memp_fget(mpf, &mpgno, ip, dbc->txn,
	    DB_MPOOL_DIRTY, &mmeta)) != 0)
		goto err;

	/*
	 * Now update the hash meta-data page to reflect where the first
	 * set of buckets are actually located.
	 */
	meta->spares[0] = mmeta->last_pgno + 1;
	for (i = 0; i < NCACHED && meta->spares[i] != PGNO_INVALID; i++)
		meta->spares[i] = meta->spares[0];

	/* The new meta data page is now complete; log it. */
	if ((ret = __db_log_page(mdbp,
	    txn, &meta->dbmeta.lsn, dbp->meta_pgno, (PAGE *)meta)) != 0)
		goto err;

	/* Reflect the group allocation. */
	if (DBENV_LOGGING(env)
#if !defined(DEBUG_WOP)
	    && txn != NULL
#endif
	)
		if ((ret = __ham_groupalloc_log(mdbp, txn,
		    &LSN(mmeta), 0, &LSN(mmeta), meta->spares[0],
		    meta->max_bucket + 1, 0, mmeta->last_pgno)) != 0)
			goto err;

	/* Release the new meta-data page. */
	if ((ret = __memp_fput(mpf, ip, meta, dbc->priority)) != 0)
		goto err;
	meta = NULL;

	lpgno += mmeta->last_pgno;

	/* Now allocate the final hash bucket. */
	if ((ret = __memp_fget(mpf, &lpgno, ip, dbc->txn,
	    DB_MPOOL_CREATE | DB_MPOOL_DIRTY, &h)) != 0)
		goto err;

	mmeta->last_pgno = lpgno;
	P_INIT(h, dbp->pgsize, lpgno, PGNO_INVALID, PGNO_INVALID, 0, P_HASH);
	LSN(h) = LSN(mmeta);
	if ((ret = __memp_fput(mpf, ip, h, dbc->priority)) != 0)
		goto err;

err:	/* Now put the master-metadata page back. */
	if (mmeta != NULL && (t_ret = __memp_fput(mpf,
		ip, mmeta, dbc->priority)) != 0 && ret == 0)
		ret = t_ret;
	if ((t_ret = __LPUT(dbc, mmlock)) != 0 && ret == 0)
		ret = t_ret;
	if (meta != NULL && (t_ret = __memp_fput(mpf,
	    ip, meta, dbc->priority)) != 0 && ret == 0)
		ret = t_ret;
	if ((t_ret = __LPUT(dbc, metalock)) != 0 && ret == 0)
		ret = t_ret;
	if (dbc != NULL)
		if ((t_ret = __dbc_close(dbc)) != 0 && ret == 0)
			ret = t_ret;
	return (ret);
}