/* id2entry.c - routines to deal with the id2entry database */
/* $OpenLDAP$ */
/* This work is part of OpenLDAP Software <http://www.openldap.org/>.
 *
 * Copyright 2000-2012 The OpenLDAP Foundation.
 * All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted only as authorized by the OpenLDAP
 * Public License.
 *
 * A copy of this license is available in the file LICENSE in the
 * top-level directory of the distribution or, alternatively, at
 * <http://www.OpenLDAP.org/license.html>.
 */

#include "portable.h"

#include <stdio.h>
#include <ac/string.h>
#include <ac/errno.h>

#include "back-mdb.h"

typedef struct Ecount {
	ber_len_t len;
	int nattrs;
	int nvals;
	int offset;
} Ecount;

static int mdb_entry_partsize(struct mdb_info *mdb, MDB_txn *txn, Entry *e,
	Ecount *eh);
static int mdb_entry_encode(Operation *op, Entry *e, MDB_val *data,
	Ecount *ec);
static Entry *mdb_entry_alloc( Operation *op, int nattrs, int nvals );

#define ADD_FLAGS	(MDB_NOOVERWRITE|MDB_APPEND)

static int mdb_id2entry_put(
	Operation *op,
	MDB_txn *txn,
	MDB_cursor *mc,
	Entry *e,
	int flag )
{
	struct mdb_info *mdb = (struct mdb_info *) op->o_bd->be_private;
	Ecount ec;
	MDB_val key, data;
	int rc;

	/* We only store rdns, and they go in the dn2id database. */

	key.mv_data = &e->e_id;
	key.mv_size = sizeof(ID);

	rc = mdb_entry_partsize( mdb, txn, e, &ec );
	if (rc)
		return LDAP_OTHER;

	flag |= MDB_RESERVE;

again:
	data.mv_size = ec.len;
	if ( mc )
		rc = mdb_cursor_put( mc, &key, &data, flag );
	else
		rc = mdb_put( txn, mdb->mi_id2entry, &key, &data, flag );
	if (rc == MDB_SUCCESS) {
		rc = mdb_entry_encode( op, e, &data, &ec );
		if( rc != LDAP_SUCCESS )
			return LDAP_OTHER;
	}
	if (rc) {
		/* Was there a hole from slapadd? */
		if ( (flag & MDB_NOOVERWRITE) && data.mv_size == 0 ) {
			flag ^= ADD_FLAGS;
			goto again;
		}
		Debug( LDAP_DEBUG_ANY,
			"mdb_id2entry_put: mdb_put failed: %s(%d) \"%s\"\n",
			mdb_strerror(rc), rc,
			e->e_nname.bv_val );
		if ( rc != MDB_KEYEXIST )
			rc = LDAP_OTHER;
	}
	return rc;
}

/*
 * This routine adds (or updates) an entry on disk.
 * The cache should be already be updated.
 */


int mdb_id2entry_add(
	Operation *op,
	MDB_txn *txn,
	MDB_cursor *mc,
	Entry *e )
{
	return mdb_id2entry_put(op, txn, mc, e, ADD_FLAGS);
}

int mdb_id2entry_update(
	Operation *op,
	MDB_txn *txn,
	MDB_cursor *mc,
	Entry *e )
{
	return mdb_id2entry_put(op, txn, mc, e, 0);
}

int mdb_id2entry(
	Operation *op,
	MDB_cursor *mc,
	ID id,
	Entry **e )
{
	struct mdb_info *mdb = (struct mdb_info *) op->o_bd->be_private;
	MDB_val key, data;
	int rc = 0;

	*e = NULL;

	key.mv_data = &id;
	key.mv_size = sizeof(ID);

	/* fetch it */
	rc = mdb_cursor_get( mc, &key, &data, MDB_SET );
	if ( rc == MDB_NOTFOUND ) {
		/* Looking for root entry on an empty-dn suffix? */
		if ( !id && BER_BVISEMPTY( &op->o_bd->be_nsuffix[0] )) {
			struct berval gluebv = BER_BVC("glue");
			Entry *r = mdb_entry_alloc(op, 2, 4);
			Attribute *a = r->e_attrs;
			struct berval *bptr;

			r->e_id = 0;
			r->e_ocflags = SLAP_OC_GLUE|SLAP_OC__END;
			bptr = a->a_vals;
			a->a_flags = SLAP_ATTR_DONT_FREE_DATA | SLAP_ATTR_DONT_FREE_VALS;
			a->a_desc = slap_schema.si_ad_objectClass;
			a->a_nvals = a->a_vals;
			a->a_numvals = 1;
			*bptr++ = gluebv;
			BER_BVZERO(bptr);
			bptr++;
			a->a_next = a+1;
			a = a->a_next;
			a->a_flags = SLAP_ATTR_DONT_FREE_DATA | SLAP_ATTR_DONT_FREE_VALS;
			a->a_desc = slap_schema.si_ad_structuralObjectClass;
			a->a_vals = bptr;
			a->a_nvals = a->a_vals;
			a->a_numvals = 1;
			*bptr++ = gluebv;
			BER_BVZERO(bptr);
			a->a_next = NULL;
			*e = r;
			return MDB_SUCCESS;
		}
	}
	if ( rc ) return rc;

	rc = mdb_entry_decode( op, &data, e );
	if ( rc ) return rc;

	(*e)->e_id = id;
	(*e)->e_name.bv_val = NULL;
	(*e)->e_nname.bv_val = NULL;

	return rc;
}

int mdb_id2entry_delete(
	BackendDB *be,
	MDB_txn *tid,
	Entry *e )
{
	struct mdb_info *mdb = (struct mdb_info *) be->be_private;
	MDB_dbi dbi = mdb->mi_id2entry;
	MDB_val key;
	int rc;

	key.mv_data = &e->e_id;
	key.mv_size = sizeof(ID);

	/* delete from database */
	rc = mdb_del( tid, dbi, &key, NULL );

	return rc;
}

static Entry * mdb_entry_alloc(
	Operation *op,
	int nattrs,
	int nvals )
{
	Entry *e = op->o_tmpalloc( sizeof(Entry) +
		nattrs * sizeof(Attribute) +
		nvals * sizeof(struct berval), op->o_tmpmemctx );
	BER_BVZERO(&e->e_bv);
	e->e_private = e;
	if (nattrs) {
		e->e_attrs = (Attribute *)(e+1);
		e->e_attrs->a_vals = (struct berval *)(e->e_attrs+nattrs);
	} else {
		e->e_attrs = NULL;
	}

	return e;
}

int mdb_entry_return(
	Operation *op,
	Entry *e
)
{
	if ( e->e_private ) {
		if ( op->o_hdr ) {
			op->o_tmpfree( e->e_nname.bv_val, op->o_tmpmemctx );
			op->o_tmpfree( e->e_name.bv_val, op->o_tmpmemctx );
			op->o_tmpfree( e, op->o_tmpmemctx );
		} else {
			ch_free( e->e_nname.bv_val );
			ch_free( e->e_name.bv_val );
			ch_free( e );
		}
	} else {
		entry_free( e );
	}
	return 0;
}

int mdb_entry_release(
	Operation *op,
	Entry *e,
	int rw )
{
	struct mdb_info *mdb = (struct mdb_info *) op->o_bd->be_private;
	struct mdb_op_info *moi = NULL;
	int rc;
 
	/* slapMode : SLAP_SERVER_MODE, SLAP_TOOL_MODE,
			SLAP_TRUNCATE_MODE, SLAP_UNDEFINED_MODE */
 
	mdb_entry_return( op, e );
	if ( slapMode == SLAP_SERVER_MODE ) {
		OpExtra *oex;
		LDAP_SLIST_FOREACH( oex, &op->o_extra, oe_next ) {
			if ( oex->oe_key == mdb ) {
				moi = (mdb_op_info *)oex;
				/* If it was setup by entry_get we should probably free it */
				if ( moi->moi_flag & MOI_FREEIT ) {
					moi->moi_ref--;
					if ( moi->moi_ref < 1 ) {
						mdb_txn_reset( moi->moi_txn );
						moi->moi_ref = 0;
						LDAP_SLIST_REMOVE( &op->o_extra, &moi->moi_oe, OpExtra, oe_next );
						op->o_tmpfree( moi, op->o_tmpmemctx );
					}
				}
				break;
			}
		}
	}
 
	return 0;
}

/* return LDAP_SUCCESS IFF we can retrieve the specified entry.
 */
int mdb_entry_get(
	Operation *op,
	struct berval *ndn,
	ObjectClass *oc,
	AttributeDescription *at,
	int rw,
	Entry **ent )
{
	struct mdb_info *mdb = (struct mdb_info *) op->o_bd->be_private;
	struct mdb_op_info *moi = NULL;
	MDB_txn *txn = NULL;
	Entry *e = NULL;
	int	rc;
	const char *at_name = at ? at->ad_cname.bv_val : "(null)";

	Debug( LDAP_DEBUG_ARGS,
		"=> mdb_entry_get: ndn: \"%s\"\n", ndn->bv_val, 0, 0 ); 
	Debug( LDAP_DEBUG_ARGS,
		"=> mdb_entry_get: oc: \"%s\", at: \"%s\"\n",
		oc ? oc->soc_cname.bv_val : "(null)", at_name, 0);

	rc = mdb_opinfo_get( op, mdb, rw == 0, &moi );
	if ( rc )
		return LDAP_OTHER;
	txn = moi->moi_txn;

	/* can we find entry */
	rc = mdb_dn2entry( op, txn, NULL, ndn, &e, 0 );
	switch( rc ) {
	case MDB_NOTFOUND:
	case 0:
		break;
	default:
		return (rc != LDAP_BUSY) ? LDAP_OTHER : LDAP_BUSY;
	}
	if (e == NULL) {
		Debug( LDAP_DEBUG_ACL,
			"=> mdb_entry_get: cannot find entry: \"%s\"\n",
				ndn->bv_val, 0, 0 ); 
		rc = LDAP_NO_SUCH_OBJECT;
		goto return_results;
	}
	
	Debug( LDAP_DEBUG_ACL,
		"=> mdb_entry_get: found entry: \"%s\"\n",
		ndn->bv_val, 0, 0 ); 

	if ( oc && !is_entry_objectclass( e, oc, 0 )) {
		Debug( LDAP_DEBUG_ACL,
			"<= mdb_entry_get: failed to find objectClass %s\n",
			oc->soc_cname.bv_val, 0, 0 ); 
		rc = LDAP_NO_SUCH_ATTRIBUTE;
		goto return_results;
	}

	/* NOTE: attr_find() or attrs_find()? */
	if ( at && attr_find( e->e_attrs, at ) == NULL ) {
		Debug( LDAP_DEBUG_ACL,
			"<= mdb_entry_get: failed to find attribute %s\n",
			at->ad_cname.bv_val, 0, 0 ); 
		rc = LDAP_NO_SUCH_ATTRIBUTE;
		goto return_results;
	}

return_results:
	if( rc != LDAP_SUCCESS ) {
		/* free entry */
		if ( e )
			mdb_entry_return( op, e );

		if (moi->moi_ref == 1) {
			LDAP_SLIST_REMOVE( &op->o_extra, &moi->moi_oe, OpExtra, oe_next );
			mdb_txn_reset( txn );
			op->o_tmpfree( moi, op->o_tmpmemctx );
		}
	} else {
		*ent = e;
	}

	Debug( LDAP_DEBUG_TRACE,
		"mdb_entry_get: rc=%d\n",
		rc, 0, 0 ); 
	return(rc);
}

static void
mdb_reader_free( void *key, void *data )
{
	MDB_txn *txn = data;

	if ( txn ) mdb_txn_abort( txn );
}

/* free up any keys used by the main thread */
void
mdb_reader_flush( MDB_env *env )
{
	void *data;
	void *ctx = ldap_pvt_thread_pool_context();

	if ( !ldap_pvt_thread_pool_getkey( ctx, env, &data, NULL ) ) {
		ldap_pvt_thread_pool_setkey( ctx, env, NULL, 0, NULL, NULL );
		mdb_reader_free( env, data );
	}
}

int
mdb_opinfo_get( Operation *op, struct mdb_info *mdb, int rdonly, mdb_op_info **moip )
{
	int rc, renew = 0;
	void *data;
	void *ctx;
	mdb_op_info *moi = NULL;
	OpExtra *oex;

	assert( op != NULL );

	if ( !mdb || !moip ) return -1;

	/* If no op was provided, try to find the ctx anyway... */
	if ( op ) {
		ctx = op->o_threadctx;
	} else {
		ctx = ldap_pvt_thread_pool_context();
	}

	if ( op ) {
		LDAP_SLIST_FOREACH( oex, &op->o_extra, oe_next ) {
			if ( oex->oe_key == mdb ) break;
		}
		moi = (mdb_op_info *)oex;
	}

	if ( !moi ) {
		moi = *moip;

		if ( !moi ) {
			if ( op ) {
				moi = op->o_tmpalloc(sizeof(struct mdb_op_info),op->o_tmpmemctx);
			} else {
				moi = ch_malloc(sizeof(mdb_op_info));
			}
			moi->moi_flag = MOI_FREEIT;
			*moip = moi;
		}
		LDAP_SLIST_INSERT_HEAD( &op->o_extra, &moi->moi_oe, oe_next );
		moi->moi_oe.oe_key = mdb;
		moi->moi_ref = 0;
		moi->moi_txn = NULL;
	}

	if ( !rdonly ) {
		/* This op started as a reader, but now wants to write. */
		if ( moi->moi_flag & MOI_READER ) {
			moi = *moip;
			LDAP_SLIST_INSERT_HEAD( &op->o_extra, &moi->moi_oe, oe_next );
		} else {
		/* This op is continuing an existing write txn */
			*moip = moi;
		}
		moi->moi_ref++;
		if ( !moi->moi_txn ) {
			rc = mdb_txn_begin( mdb->mi_dbenv, NULL, 0, &moi->moi_txn );
			if (rc) {
				Debug( LDAP_DEBUG_ANY, "mdb_opinfo_get: err %s(%d)\n",
					mdb_strerror(rc), rc, 0 );
			}
			return rc;
		}
		return 0;
	}

	/* OK, this is a reader */
	if ( !moi->moi_txn ) {
		if ( !ctx ) {
			/* Shouldn't happen unless we're single-threaded */
			rc = mdb_txn_begin( mdb->mi_dbenv, NULL, MDB_RDONLY, &moi->moi_txn );
			if (rc) {
				Debug( LDAP_DEBUG_ANY, "mdb_opinfo_get: err %s(%d)\n",
					mdb_strerror(rc), rc, 0 );
			}
			return rc;
		}
		if ( ldap_pvt_thread_pool_getkey( ctx, mdb->mi_dbenv, &data, NULL ) ) {
			rc = mdb_txn_begin( mdb->mi_dbenv, NULL, MDB_RDONLY, &moi->moi_txn );
			if (rc) {
				Debug( LDAP_DEBUG_ANY, "mdb_opinfo_get: err %s(%d)\n",
					mdb_strerror(rc), rc, 0 );
				return rc;
			}
			data = moi->moi_txn;
			if ( ( rc = ldap_pvt_thread_pool_setkey( ctx, mdb->mi_dbenv,
				data, mdb_reader_free, NULL, NULL ) ) ) {
				mdb_txn_abort( moi->moi_txn );
				moi->moi_txn = NULL;
				Debug( LDAP_DEBUG_ANY, "mdb_opinfo_get: thread_pool_setkey failed err (%d)\n",
					rc, 0, 0 );
				return rc;
			}
		} else {
			moi->moi_txn = data;
			renew = 1;
		}
		moi->moi_flag |= MOI_READER;
	}
	if ( moi->moi_ref < 1 ) {
		moi->moi_ref = 0;
	}
	if ( renew ) {
		mdb_txn_renew( moi->moi_txn );
	}
	moi->moi_ref++;
	if ( *moip != moi )
		*moip = moi;

	return 0;
}

/* Count up the sizes of the components of an entry */
static int mdb_entry_partsize(struct mdb_info *mdb, MDB_txn *txn, Entry *e,
	Ecount *eh)
{
	ber_len_t len;
	int i, nat = 0, nval = 0, nnval = 0;
	Attribute *a;

	len = 4*sizeof(int);	/* nattrs, nvals, ocflags, offset */
	for (a=e->e_attrs; a; a=a->a_next) {
		/* For AttributeDesc, we only store the attr index */
		nat++;
		if (a->a_desc->ad_index >= MDB_MAXADS) {
			Debug( LDAP_DEBUG_ANY, "mdb_entry_partsize: too many AttributeDescriptions used\n",
				0, 0, 0 );
			return LDAP_OTHER;
		}
		if (!mdb->mi_adxs[a->a_desc->ad_index]) {
			int rc = mdb_ad_get(mdb, txn, a->a_desc);
			if (rc)
				return rc;
		}
		len += 2*sizeof(int);	/* AD index, numvals */
		nval += a->a_numvals + 1;	/* empty berval at end */
		for (i=0; i<a->a_numvals; i++) {
			len += a->a_vals[i].bv_len + 1 + sizeof(int);	/* len */
		}
		if (a->a_nvals != a->a_vals) {
			nval += a->a_numvals + 1;
			nnval++;
			for (i=0; i<a->a_numvals; i++) {
				len += a->a_nvals[i].bv_len + 1 + sizeof(int);;
			}
		}
	}
	/* padding */
	len = (len + sizeof(ID)-1) & ~(sizeof(ID)-1);
	eh->len = len;
	eh->nattrs = nat;
	eh->nvals = nval;
	eh->offset = nat + nval - nnval;
	return 0;
}

#define HIGH_BIT (1<<(sizeof(unsigned int)*CHAR_BIT-1))

/* Flatten an Entry into a buffer. The buffer starts with the count of the
 * number of attributes in the entry, the total number of values in the
 * entry, and the e_ocflags. It then contains a list of integers for each
 * attribute. For each attribute the first integer gives the index of the
 * matching AttributeDescription, followed by the number of values in the
 * attribute. If the high bit is set, the attribute also has normalized
 * values present. (Note - a_numvals is an unsigned int, so this means
 * it's possible to receive an attribute that we can't encode due to size
 * overflow. In practice, this should not be an issue.) Then the length
 * of each value is listed. If there are normalized values, their lengths
 * come next. This continues for each attribute. After all of the lengths
 * for the last attribute, the actual values are copied, with a NUL
 * terminator after each value. The buffer is padded to the sizeof(ID).
 * The entire buffer size is precomputed so that a single malloc can be
 * performed.
 */
static int mdb_entry_encode(Operation *op, Entry *e, MDB_val *data, Ecount *eh)
{
	struct mdb_info *mdb = (struct mdb_info *) op->o_bd->be_private;
	ber_len_t len, i;
	int rc;
	Attribute *a;
	unsigned char *ptr;
	unsigned int *lp, l;

	Debug( LDAP_DEBUG_TRACE, "=> mdb_entry_encode(0x%08lx): %s\n",
		(long) e->e_id, e->e_dn, 0 );

	/* make sure e->e_ocflags is set */
	if (is_entry_referral(e))
		;	/* empty */

	lp = (unsigned int *)data->mv_data;
	*lp++ = eh->nattrs;
	*lp++ = eh->nvals;
	*lp++ = (unsigned int)e->e_ocflags;
	*lp++ = eh->offset;
	ptr = (unsigned char *)(lp + eh->offset);

	for (a=e->e_attrs; a; a=a->a_next) {
		*lp++ = mdb->mi_adxs[a->a_desc->ad_index];
		l = a->a_numvals;
		if (a->a_nvals != a->a_vals)
			l |= HIGH_BIT;
		*lp++ = l;
		if (a->a_vals) {
			for (i=0; a->a_vals[i].bv_val; i++);
			assert( i == a->a_numvals );
			for (i=0; i<a->a_numvals; i++) {
				*lp++ = a->a_vals[i].bv_len;
				memcpy(ptr, a->a_vals[i].bv_val,
					a->a_vals[i].bv_len);
				ptr += a->a_vals[i].bv_len;
				*ptr++ = '\0';
			}
			if (a->a_nvals != a->a_vals) {
				for (i=0; i<a->a_numvals; i++) {
					*lp++ = a->a_nvals[i].bv_len;
					memcpy(ptr, a->a_nvals[i].bv_val,
						a->a_nvals[i].bv_len);
					ptr += a->a_nvals[i].bv_len;
					*ptr++ = '\0';
				}
			}
		}
	}

	Debug( LDAP_DEBUG_TRACE, "<= mdb_entry_encode(0x%08lx): %s\n",
		(long) e->e_id, e->e_dn, 0 );

	return 0;
}

/* Retrieve an Entry that was stored using entry_encode above.
 *
 * Note: everything is stored in a single contiguous block, so
 * you can not free individual attributes or names from this
 * structure. Attempting to do so will likely corrupt memory.
 */

int mdb_entry_decode(Operation *op, MDB_val *data, Entry **e)
{
	struct mdb_info *mdb = (struct mdb_info *) op->o_bd->be_private;
	int i, j, nattrs, nvals;
	int rc;
	Attribute *a;
	Entry *x;
	const char *text;
	AttributeDescription *ad;
	unsigned int *lp = (unsigned int *)data->mv_data;
	unsigned char *ptr;
	BerVarray bptr;

	Debug( LDAP_DEBUG_TRACE,
		"=> mdb_entry_decode:\n",
		0, 0, 0 );

	nattrs = *lp++;
	nvals = *lp++;
	x = mdb_entry_alloc(op, nattrs, nvals);
	x->e_ocflags = *lp++;
	if (!nvals) {
		goto done;
	}
	a = x->e_attrs;
	bptr = a->a_vals;
	i = *lp++;
	ptr = (unsigned char *)(lp + i);

	for (;nattrs>0; nattrs--) {
		int have_nval = 0;
		a->a_desc = mdb->mi_ads[*lp++];
		a->a_flags = SLAP_ATTR_DONT_FREE_DATA | SLAP_ATTR_DONT_FREE_VALS;
		a->a_numvals = *lp++;
		if (a->a_numvals & HIGH_BIT) {
			a->a_numvals ^= HIGH_BIT;
			have_nval = 1;
		}
		a->a_vals = bptr;
		for (i=0; i<a->a_numvals; i++) {
			bptr->bv_len = *lp++;;
			bptr->bv_val = (char *)ptr;
			ptr += bptr->bv_len+1;
			bptr++;
		}
		bptr->bv_val = NULL;
		bptr->bv_len = 0;
		bptr++;

		if (have_nval) {
			a->a_nvals = bptr;
			for (i=0; i<a->a_numvals; i++) {
				bptr->bv_len = *lp++;
				bptr->bv_val = (char *)ptr;
				ptr += bptr->bv_len+1;
				bptr++;
			}
			bptr->bv_val = NULL;
			bptr->bv_len = 0;
			bptr++;
		} else {
			a->a_nvals = a->a_vals;
		}
		/* FIXME: This is redundant once a sorted entry is saved into the DB */
		if ( a->a_desc->ad_type->sat_flags & SLAP_AT_SORTED_VAL ) {
			rc = slap_sort_vals( (Modifications *)a, &text, &j, NULL );
			if ( rc == LDAP_SUCCESS ) {
				a->a_flags |= SLAP_ATTR_SORTED_VALS;
			} else if ( rc == LDAP_TYPE_OR_VALUE_EXISTS ) {
				/* should never happen */
				Debug( LDAP_DEBUG_ANY,
					"mdb_entry_decode: attributeType %s value #%d provided more than once\n",
					a->a_desc->ad_cname.bv_val, j, 0 );
				return rc;
			}
		}
		a->a_next = a+1;
		a = a->a_next;
	}
	a[-1].a_next = NULL;
done:

	Debug(LDAP_DEBUG_TRACE, "<= mdb_entry_decode\n",
		0, 0, 0 );
	*e = x;
	return 0;
}