path: root/source4/lib/ldb/ldb_sqlite3/ldb_sqlite3.c

/* 
   ldb database library
   
   Copyright (C) Derrell Lipman  2005
   
   ** NOTE! The following LGPL license applies to the ldb
   ** 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 2 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, write to the Free Software
   Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
*/

/*
 *  Name: ldb
 *
 *  Component: ldb sqlite3 backend
 *
 *  Description: core files for SQLITE3 backend
 *
 *  Author: Derrell Lipman (based on Andrew Tridgell's LDAP backend)
 */

#include <stdarg.h>
#include "includes.h"
#include "ldb/include/ldb.h"
#include "ldb/include/ldb_private.h"
#include "ldb/ldb_sqlite3/ldb_sqlite3.h"

/*
 * Macros used throughout
 */

#ifndef FALSE
# define FALSE  (0)
# define TRUE   (! FALSE)
#endif

#define RESULT_ATTR_TABLE       "temp_result_attrs"

//#define TEMPTAB                 /* for testing, create non-temporary table */
#define TEMPTAB                 "TEMPORARY"

/*
 * Static variables
 */
sqlite3_stmt *  stmtGetEID = NULL;

static char *lsqlite3_tprintf(TALLOC_CTX *mem_ctx, const char *fmt, ...)
{
	char *str, *ret;
	va_list ap;

	va_start(ap, fmt);
        str = sqlite3_vmprintf(fmt, ap);
	va_end(ap);

	if (str == NULL) return NULL;

	ret = talloc_strdup(mem_ctx, str);
	if (ret == NULL) {
		sqlite3_free(str);
		return NULL;
	}

	sqlite3_free(str);
	return ret;
}

static unsigned char        base160tab[161] = {
        48 ,49 ,50 ,51 ,52 ,53 ,54 ,55 ,56 ,57 , /* 0-9 */
        58 ,59 ,65 ,66 ,67 ,68 ,69 ,70 ,71 ,72 , /* : ; A-H */
        73 ,74 ,75 ,76 ,77 ,78 ,79 ,80 ,81 ,82 , /* I-R */
        83 ,84 ,85 ,86 ,87 ,88 ,89 ,90 ,97 ,98 , /* S-Z , a-b */
        99 ,100,101,102,103,104,105,106,107,108, /* c-l */
        109,110,111,112,113,114,115,116,117,118, /* m-v */
        119,120,121,122,160,161,162,163,164,165, /* w-z, latin1 */
        166,167,168,169,170,171,172,173,174,175, /* latin1 */
        176,177,178,179,180,181,182,183,184,185, /* latin1 */
        186,187,188,189,190,191,192,193,194,195, /* latin1 */
        196,197,198,199,200,201,202,203,204,205, /* latin1 */
        206,207,208,209,210,211,212,213,214,215, /* latin1 */
        216,217,218,219,220,221,222,223,224,225, /* latin1 */
        226,227,228,229,230,231,232,233,234,235, /* latin1 */
        236,237,238,239,240,241,242,243,244,245, /* latin1 */
        246,247,248,249,250,251,252,253,254,255, /* latin1 */
        '\0'
};


/*
 * base160()
 *
 * Convert an unsigned long integer into a base160 representation of the
 * number.
 *
 * Parameters:
 *   val --
 *     value to be converted
 *
 *   result --
 *     character array, 5 bytes long, into which the base160 representation
 *     will be placed.  The result will be a four-digit representation of the
 *     number (with leading zeros prepended as necessary), and null
 *     terminated.
 *
 * Returns:
 *   Nothing
 */
static void
base160_sql(sqlite3_context * hContext,
            int argc,
            sqlite3_value ** argv)
{
    int             i;
    long long       val;
    char            result[5];

    val = sqlite3_value_int64(argv[0]);

    for (i = 3; i >= 0; i--) {
        
        result[i] = base160tab[val % 160];
        val /= 160;
    }

    result[4] = '\0';

    sqlite3_result_text(hContext, result, -1, SQLITE_TRANSIENT);
}


/*
 * base160next_sql()
 *
 * This function enhances sqlite by adding a "base160_next()" function which is
 * accessible via queries.
 *
 * Retrieve the next-greater number in the base160 sequence for the terminal
 * tree node (the last four digits).  Only one tree level (four digits) is
 * operated on.
 *
 * Input:
 *   A character string: either an empty string (in which case no operation is
 *   performed), or a string of base160 digits with a length of a multiple of
 *   four digits.
 *
 * Output:
 *   Upon return, the trailing four digits (one tree level) will have been
 *   incremented by 1.
 */
static void
base160next_sql(sqlite3_context * hContext,
                int argc,
                sqlite3_value ** argv)
{
        int                         i;
        int                         len;
        unsigned char *             pTab;
        unsigned char *             pBase160 =
                strdup(sqlite3_value_text(argv[0]));
        unsigned char *             pStart = pBase160;

        /*
         * We need a minimum of four digits, and we will always get a multiple
         * of four digits.
         */
        if (pBase160 != NULL &&
            (len = strlen(pBase160)) >= 4 &&
            len % 4 == 0) {

                if (pBase160 == NULL) {

                        sqlite3_result_null(hContext);
                        return;
                }

                pBase160 += strlen(pBase160) - 1;

                /* We only carry through four digits: one level in the tree */
                for (i = 0; i < 4; i++) {

                        /* What base160 value does this digit have? */
                        pTab = strchr(base160tab, *pBase160);

                        /* Is there a carry? */
                        if (pTab < base160tab + sizeof(base160tab) - 1) {

                                /*
                                 * Nope.  Just increment this value and we're
                                 * done.
                                 */
                                *pBase160 = *++pTab;
                                break;
                        } else {

                                /*
                                 * There's a carry.  This value gets
                                 * base160tab[0], we decrement the buffer
                                 * pointer to get the next higher-order digit,
                                 * and continue in the loop.
                                 */
                                *pBase160-- = base160tab[0];
                        }
                }

                sqlite3_result_text(hContext,
                                    pStart,
                                    strlen(pStart),
                                    free);
        } else {
                sqlite3_result_value(hContext, argv[0]);
                if (pBase160 != NULL) {
                        free(pBase160);
                }
        }
}

static char *parsetree_to_sql(struct ldb_module *module,
			      void *mem_ctx,
			      const struct ldb_parse_tree *t)
{
	const struct ldb_attrib_handler *h;
	struct ldb_val value, subval;
	char *wild_card_string;
	char *child, *tmp;
	char *ret = NULL;
	int i;


	switch(t->operation) {
	case LDB_OP_AND:

		tmp = parsetree_to_sql(module, mem_ctx, t->u.list.elements[0]);
		if (tmp == NULL) return NULL;

		for (i = 1; i < t->u.list.num_elements; i++) {

			child = parsetree_to_sql(module, mem_ctx, t->u.list.elements[i]);
			if (child == NULL) return NULL;

			tmp = talloc_asprintf_append(tmp, "INTERSECT %s ", child);
			if (tmp == NULL) return NULL;
		}

		ret = talloc_asprintf(mem_ctx, "SELECT * FROM ( %s )\n", tmp);

		return ret;
                
	case LDB_OP_OR:

		tmp = parsetree_to_sql(module, mem_ctx, t->u.list.elements[0]);
		if (tmp == NULL) return NULL;

		for (i = 1; i < t->u.list.num_elements; i++) {

			child = parsetree_to_sql(module, mem_ctx, t->u.list.elements[i]);
			if (child == NULL) return NULL;

			tmp = talloc_asprintf_append(tmp, "UNION %s ", child);
			if (tmp == NULL) return NULL;
		}

		return talloc_asprintf(mem_ctx, "SELECT * FROM ( %s )", tmp);

	case LDB_OP_NOT:

		child = parsetree_to_sql(module, mem_ctx, t->u.isnot.child);
		if (child == NULL) return NULL;

		return talloc_asprintf(mem_ctx,
					"SELECT eid FROM ldb_entry "
					"WHERE eid NOT IN ( %s )", child);

	case LDB_OP_EQUALITY:
		/*
		 * For simple searches, we want to retrieve the list of EIDs that
		 * match the criteria.
		*/
		h = ldb_attrib_handler(module->ldb, t->u.equality.attr);

		/* Get a canonicalised copy of the data */
		h->canonicalise_fn(module->ldb, mem_ctx, &(t->u.equality.value), &value);
		if (value.data == NULL) {
			return NULL;
		}

		if (strcasecmp(t->u.equality.attr, "objectclass") == 0) {
		/*
		 * For object classes, we want to search for all objectclasses
		 * that are subclasses as well.
		*/
			return lsqlite3_tprintf(mem_ctx,
					"SELECT eid  FROM ldb_attribute_values\n"
					"WHERE norm_attr_name = 'OBJECTCLASS' "
					"AND norm_attr_value IN\n"
					"  (SELECT class_name FROM ldb_object_classes\n"
					"   WHERE tree_key GLOB\n"
					"     (SELECT tree_key FROM ldb_object_classes\n"
					"      WHERE class_name = '%q'\n"
					"     ) || '*'\n"
					"  )\n", value.data);

		} else if (strcasecmp(t->u.equality.attr, "dn") == 0) {
			/* DN query is a special ldb case */
		 	char *cdn = ldb_dn_linearize_casefold(module->ldb,
							      ldb_dn_explode(module->ldb,
							      value.data));

			return lsqlite3_tprintf(mem_ctx,
						"SELECT eid FROM ldb_entry "
						"WHERE norm_dn = '%q'", cdn);

		} else {
			/* A normal query. */
			return lsqlite3_tprintf(mem_ctx,
						"SELECT eid FROM ldb_attribute_values "
						"WHERE norm_attr_name = upper('%q') "
						"AND norm_attr_value = '%q'",
						t->u.equality.attr,
						value.data);

		}

	case LDB_OP_SUBSTRING:

		wild_card_string = talloc_strdup(mem_ctx,
					(t->u.substring.start_with_wildcard)?"*":"");
		if (wild_card_string == NULL) return NULL;

		for (i = 0; t->u.substring.chunks[i]; i++) {
			wild_card_string = talloc_asprintf_append(wild_card_string, "%s*",
							t->u.substring.chunks[i]);
			if (wild_card_string == NULL) return NULL;
		}

		if ( ! t->u.substring.end_with_wildcard ) {
			/* remove last wildcard */
			wild_card_string[strlen(wild_card_string) - 1] = '\0';
		}

		h = ldb_attrib_handler(module->ldb, t->u.substring.attr);

		subval.data = wild_card_string;
		subval.length = strlen(wild_card_string) + 1;

		/* Get a canonicalised copy of the data */
		h->canonicalise_fn(module->ldb, mem_ctx, &(subval), &value);
		if (value.data == NULL) {
			return NULL;
		}

		return lsqlite3_tprintf(mem_ctx,
					"SELECT eid FROM ldb_attribute_values "
					"WHERE norm_attr_name = upper('%q') "
					"AND norm_attr_value GLOB '%q'",
					t->u.substring.attr,
					value.data);

	case LDB_OP_GREATER:
		h = ldb_attrib_handler(module->ldb, t->u.equality.attr);

		/* Get a canonicalised copy of the data */
		h->canonicalise_fn(module->ldb, mem_ctx, &(t->u.equality.value), &value);
		if (value.data == NULL) {
			return NULL;
		}

		return lsqlite3_tprintf(mem_ctx,
					"SELECT eid FROM ldb_attribute_values "
					"WHERE norm_attr_name = upper('%q') "
					"AND norm_attr_value >= '%q'",
					t->u.equality.attr,
					value.data);

	case LDB_OP_LESS:
		h = ldb_attrib_handler(module->ldb, t->u.equality.attr);

		/* Get a canonicalised copy of the data */
		h->canonicalise_fn(module->ldb, mem_ctx, &(t->u.equality.value), &value);
		if (value.data == NULL) {
			return NULL;
		}

		return lsqlite3_tprintf(mem_ctx,
					"SELECT eid FROM ldb_attribute_values "
					"WHERE norm_attr_name = upper('%q') "
					"AND norm_attr_value <= '%q'",
					t->u.equality.attr,
					value.data);

	case LDB_OP_PRESENT:
		if (strcasecmp(t->u.present.attr, "dn")) {
			return talloc_strdup(mem_ctx, "SELECT eid FROM ldb_entry");
		}

		return lsqlite3_tprintf(mem_ctx,
					"SELECT eid FROM ldb_attribute_values "
					"WHERE norm_attr_name = upper('%q')",
					t->u.present.attr);

	case LDB_OP_APPROX:
		h = ldb_attrib_handler(module->ldb, t->u.equality.attr);

		/* Get a canonicalised copy of the data */
		h->canonicalise_fn(module->ldb, mem_ctx, &(t->u.equality.value), &value);
		if (value.data == NULL) {
			return NULL;
		}

		return lsqlite3_tprintf(mem_ctx,
					"SELECT eid FROM ldb_attribute_values "
					"WHERE norm_attr_name = upper('%q') "
					"AND norm_attr_value LIKE '%q'",
					t->u.equality.attr,
					value.data);
		
	case LDB_OP_EXTENDED:
#warning  "work out how to handle bitops"
		return NULL;

	default:
		break;
	};

	/* should never occur */
	abort();
	return NULL;
}


/*
 * query_norows()
 *
 * This function is used for queries that are not expected to return any rows,
 * e.g. BEGIN, COMMIT, ROLLBACK, CREATE TABLE, INSERT, UPDATE, DELETE, etc.
 * There are no provisions here for returning data from rows in a table, so do
 * not pass SELECT queries to this function.
 */
static int
query_norows(const struct lsqlite3_private *lsqlite3,
             const char *pSql,
             ...)
{
        int             ret;
        int             bLoop;
        char *          p;
        sqlite3_stmt *  pStmt;
        va_list         args;
 
        /* Begin access to variable argument list */
        va_start(args, pSql);
        
        /* Format the query */
        if ((p = sqlite3_vmprintf(pSql, args)) == NULL) {
                return -1;
        }
        
        /*
         * Prepare and execute the SQL statement.  Loop allows retrying on
         * certain errors, e.g. SQLITE_SCHEMA occurs if the schema changes,
         * requiring retrying the operation.
         */
        for (bLoop = TRUE; bLoop; ) {
                
                /* Compile the SQL statement into sqlite virtual machine */
                if ((ret = sqlite3_prepare(lsqlite3->sqlite,
                                           p,
                                           -1,
                                           &pStmt,
                                           NULL)) == SQLITE_SCHEMA) {
                        if (stmtGetEID != NULL) {
                                sqlite3_finalize(stmtGetEID);
                                stmtGetEID = NULL;
                        }
                        continue;
                } else if (ret != SQLITE_OK) {
                        ret = -1;
                        break;
                }
                
                /* No rows expected, so just step through machine code once */
                if ((ret = sqlite3_step(pStmt)) == SQLITE_SCHEMA) {
                        if (stmtGetEID != NULL) {
                                sqlite3_finalize(stmtGetEID);
                                stmtGetEID = NULL;
                        }
                        (void) sqlite3_finalize(pStmt);
                        continue;
                } else if (ret != SQLITE_DONE) {
                        (void) sqlite3_finalize(pStmt);
                        ret = -1;
                        break;
                }
                
                /* Free the virtual machine */
                if ((ret = sqlite3_finalize(pStmt)) == SQLITE_SCHEMA) {
                        if (stmtGetEID != NULL) {
                                sqlite3_finalize(stmtGetEID);
                                stmtGetEID = NULL;
                        }
                        continue;
                } else if (ret != SQLITE_OK) {
                        (void) sqlite3_finalize(pStmt);
                        ret = -1;
                        break;
                }
                
                /*
                 * Normal condition is only one time through loop.  Loop is
                 * rerun in error conditions, via "continue", above.
                 */
                ret = 0;
                bLoop = FALSE;
        }
        
        /* All done with variable argument list */
        va_end(args);
        
        /* Free the memory we allocated for our query string */
        sqlite3_free(p);
        
        return ret;
}


/* obtain a named lock */
static int
lsqlite3_lock(struct ldb_module * module,
              const char * lockname)
{
	struct lsqlite3_private *   lsqlite3 = module->private_data;

/* FIXME
	if (lockname == NULL) {
		return -1;
	}
        
        if (strcmp(lockname, "transaction") == 0) {
                if (lsqlite3->lock_count == 0) {
                        if (query_norows(lsqlite3, "BEGIN EXCLUSIVE;") != 0) {
                                return -1;
                        }
                }
                ++lsqlite3->lock_count;
        }
*/
	return 0;
}

/* release a named lock */
static int
lsqlite3_unlock(struct ldb_module *module,
                const char *lockname)
{
	struct lsqlite3_private *   lsqlite3 = module->private_data;

/* FIXME
	if (lockname == NULL) {
		return -1;
	}
        
        if (strcmp(lockname, "transaction") == 0) {
                if (lsqlite3->lock_count == 1) {
                        if (query_norows(lsqlite3, "COMMIT;") != 0) {
                                query_norows(lsqlite3, "ROLLBACK;");
                        }
                } else if (lsqlite3->lock_count > 0) {
                        --lsqlite3->lock_count;
                }
        } else if (strcmp(lockname, "rollback") == 0) {
                query_norows(lsqlite3, "ROLLBACK;");
        }
*/
        return 0;
}

/*
 * query_int()
 *
 * This function is used for the common case of queries that return a single
 * integer value.
 *
 * NOTE: If more than one value is returned by the query, all but the first
 * one will be ignored.
 */
static int
query_int(const struct lsqlite3_private * lsqlite3,
          long long * pRet,
          const char * pSql,
          ...)
{
        int             ret;
        int             bLoop;
        char *          p;
        sqlite3_stmt *  pStmt;
        va_list         args;
        
        /* Begin access to variable argument list */
        va_start(args, pSql);
        
        /* Format the query */
        if ((p = sqlite3_vmprintf(pSql, args)) == NULL) {
                return SQLITE_NOMEM;
        }
        
        /*
         * Prepare and execute the SQL statement.  Loop allows retrying on
         * certain errors, e.g. SQLITE_SCHEMA occurs if the schema changes,
         * requiring retrying the operation.
         */
        for (bLoop = TRUE; bLoop; ) {
                
                /* Compile the SQL statement into sqlite virtual machine */
                if ((ret = sqlite3_prepare(lsqlite3->sqlite,
                                           p,
                                           -1,
                                           &pStmt,
                                           NULL)) == SQLITE_SCHEMA) {
                        if (stmtGetEID != NULL) {
                                sqlite3_finalize(stmtGetEID);
                                stmtGetEID = NULL;
                        }
                        continue;
                } else if (ret != SQLITE_OK) {
                        break;
                }
                
                /* One row expected */
                if ((ret = sqlite3_step(pStmt)) == SQLITE_SCHEMA) {
                        if (stmtGetEID != NULL) {
                                sqlite3_finalize(stmtGetEID);
                                stmtGetEID = NULL;
                        }
                        (void) sqlite3_finalize(pStmt);
                        continue;
                } else if (ret != SQLITE_ROW) {
                        (void) sqlite3_finalize(pStmt);
                        break;
                }
                
                /* Get the value to be returned */
                *pRet = sqlite3_column_int64(pStmt, 0);
                
                /* Free the virtual machine */
                if ((ret = sqlite3_finalize(pStmt)) == SQLITE_SCHEMA) {
                        if (stmtGetEID != NULL) {
                                sqlite3_finalize(stmtGetEID);
                                stmtGetEID = NULL;
                        }
                        continue;
                } else if (ret != SQLITE_OK) {
                        (void) sqlite3_finalize(pStmt);
                        break;
                }
                
                /*
                 * Normal condition is only one time through loop.  Loop is
                 * rerun in error conditions, via "continue", above.
                 */
                bLoop = FALSE;
        }
        
        /* All done with variable argument list */
        va_end(args);
        

        /* Free the memory we allocated for our query string */
        sqlite3_free(p);
        
        return ret;
}


/* rename a record */
static int lsqlite3_safe_rollback(sqlite3 *sqlite)
{
	char *errmsg;
	int ret;

	/* execute */
	ret = sqlite3_exec(sqlite, "ROLLBACK;", NULL, NULL, &errmsg);
	if (ret != SQLITE_OK) {
		if (errmsg) {
			printf("lsqlite3_safe_rollback: Serious Error: %s\n", errmsg);
			free(errmsg);
		}
		return -1;
	}

        return 0;
}

/* return an eid as result */
static int lsqlite3_eid_callback(void *result, int col_num, char **cols, char **names)
{
	long long *eid = (long long *)result;

	if (col_num != 1) return SQLITE_ABORT;
	if (strcasecmp(names[0], "eid") != 0) return SQLITE_ABORT;

	*eid = atoll(cols[0]);
	return SQLITE_OK;
}

struct lsqlite3_msgs {
	int count;
	struct ldb_message **msgs;
	long long current_eid;
	TALLOC_CTX *mem_ctx;
};

/*
 * add a single set of ldap message values to a ldb_message
 */

static int lsqlite3_search_callback(void *result, int col_num, char **cols, char **names)
{
	struct lsqlite3_msgs *msgs = (struct lsqlite3_msgs *)result;
	struct ldb_message *msg;
	long long eid;

	/* eid, dn, attr_name, attr_value */
	if (col_num != 4) return SQLITE_ABORT;

	eid = atoll(cols[0]);

	if (eid != msgs->current_eid) {
		msgs->msgs = talloc_realloc(msgs->mem_ctx,
					    msgs->msgs,
					    struct ldb_message *,
					    msgs->count + 2);
		if (msgs->msgs == NULL) return SQLITE_ABORT;

		msgs->msgs[msgs->count] = talloc(msgs->msgs, struct ldb_message);
		if (msgs->msgs[msgs->count] == NULL) return SQLITE_ABORT;

		msgs->msgs[msgs->count]->dn = NULL;
		msgs->msgs[msgs->count]->num_elements = 0;
		msgs->msgs[msgs->count]->elements = NULL;
		msgs->msgs[msgs->count]->private_data = NULL;

		msgs->count++;
		msgs->current_eid = eid;
	}

	msg = msgs->msgs[msgs->count -1];

	if (msg->dn == NULL) {
		msg->dn = ldb_dn_explode(msg, cols[1]);
		if (msg->dn == NULL) return SQLITE_ABORT;
	}

	msg->elements = talloc_realloc(msg,
				       msg->elements,
				       struct ldb_message_element,
				       msg->num_elements + 1);
	if (msg->elements == NULL) return SQLITE_ABORT;

	msg->elements[msg->num_elements].flags = 0;
	msg->elements[msg->num_elements].name = talloc_strdup(msg->elements, cols[2]);
	if (msg->elements[msg->num_elements].name == NULL) return SQLITE_ABORT;

	msg->elements[msg->num_elements].num_values = 1;
	msg->elements[msg->num_elements].values = talloc_array(msg->elements,
								struct ldb_val, 1);
	if (msg->elements[msg->num_elements].values == NULL) return SQLITE_ABORT;

	msg->elements[msg->num_elements].values[0].length = strlen(cols[3]);
	msg->elements[msg->num_elements].values[0].data = talloc_strdup(msg->elements, cols[3]);
	if (msg->elements[msg->num_elements].values[0].data == NULL) return SQLITE_ABORT;

	msg->num_elements++;

	return SQLITE_OK;
}


/*
 * lsqlite3_get_eid()
 * lsqlite3_get_eid_ndn()
 *
 * These functions are used for the very common case of retrieving an EID value
 * given a (normalized) DN.
 */

static long long lsqlite3_get_eid_ndn(sqlite3 *sqlite, void *mem_ctx, const char *norm_dn)
{
	char *errmsg;
	char *query;
	long long eid = -1;
	long long ret;

	/* get object eid */
	query = lsqlite3_tprintf(mem_ctx, "SELECT eid "
					  "FROM ldb_entry "
					  "WHERE norm_dn = '%q';", norm_dn);
	if (query == NULL) return -1;

	ret = sqlite3_exec(sqlite, query, lsqlite3_eid_callback, &eid, &errmsg);
	if (ret != SQLITE_OK) {
		if (errmsg) {
			printf("lsqlite3_get_eid: Fatal Error: %s\n", errmsg);
			free(errmsg);
		}
		return -1;
	}

	return eid;
}

static long long lsqlite3_get_eid(struct ldb_module *module, const struct ldb_dn *dn)
{
	TALLOC_CTX *local_ctx;
	struct lsqlite3_private *lsqlite3 = module->private_data;
	long long eid = -1;
	char *cdn;

	/* ignore ltdb specials */
	if (ldb_dn_is_special(dn)) {
		return -1;
	}

	/* create a local ctx */
	local_ctx = talloc_named(lsqlite3, 0, "lsqlite3_get_eid local context");
	if (local_ctx == NULL) {
		return -1;
	}

	cdn = ldb_dn_linearize(local_ctx, ldb_dn_casefold(module->ldb, dn));
	if (!cdn) goto done;

	eid = lsqlite3_get_eid_ndn(lsqlite3->sqlite, local_ctx, cdn);

done:
	talloc_free(local_ctx);
	return eid;
}

/*
 * Interface functions referenced by lsqlite3_ops
 */

/* search for matching records, by tree */
static int lsqlite3_search_bytree(struct ldb_module * module, const struct ldb_dn* basedn,
				  enum ldb_scope scope, struct ldb_parse_tree * tree,
				  const char * const * attrs, struct ldb_message *** res)
{
	TALLOC_CTX *local_ctx;
	struct lsqlite3_private *lsqlite3 = module->private_data;
	struct lsqlite3_msgs msgs;
	char *norm_basedn;
        char *attr_list;
	char *sqlfilter;
	char *errmsg;
	char *query;
        int ret, i;

	/* create a local ctx */
	local_ctx = talloc_named(lsqlite3, 0, "lsqlite3_search_by_tree local context");
	if (local_ctx == NULL) {
		return -1;
	}

	if (basedn) {
		norm_basedn = ldb_dn_linearize(local_ctx, ldb_dn_casefold(module->ldb, basedn));
		if (norm_basedn == NULL) goto failed;
	} else norm_basedn = talloc_strdup(local_ctx, "");

	if (*norm_basedn == '\0' &&
		(scope == LDB_SCOPE_BASE || scope == LDB_SCOPE_ONELEVEL))
			goto failed;

        /* Convert filter into a series of SQL conditions (constraints) */
	sqlfilter = parsetree_to_sql(module, local_ctx, tree);
        
        /* Initially, we don't know what the requested attributes are */
	if (attrs != NULL) {
        	attr_list = talloc_strdup(local_ctx, "AND norm_attr_name IN (");
		if (attr_list == NULL) goto failed;

		for (i = 0; attrs[i]; i++) {
			char *norm_attr_name;

                	/* If any attribute in the list is "*" then... */
			if (strcmp(attrs[i], "*") == 0) {
                        	/* we want all attribute types */
				attr_list = talloc_strdup(local_ctx, "");
				if (attr_list == NULL) goto failed;
				break;
			}

			norm_attr_name = ldb_casefold(local_ctx, attrs[i]);
			if (norm_attr_name == NULL) goto failed;

			attr_list = talloc_asprintf_append(attr_list, "'%q', ",
							   norm_attr_name);
			if (attr_list == NULL) goto failed;

		}

		/* substitute the last ',' with ')' */
		attr_list[strlen(attr_list)-2] = ')';

	} else {
		attr_list = talloc_strdup(local_ctx, "");
		if (attr_list == NULL) goto failed;
	}

        switch(scope) {
        case LDB_SCOPE_DEFAULT:
        case LDB_SCOPE_SUBTREE:
		if (*norm_basedn != '\0') {
			query = lsqlite3_tprintf(local_ctx,
				"SELECT entry.eid,\n"
				"       entry.dn,\n"
				"       av.attr_name,\n"
				"       av.attr_value\n"
				"  FROM ldb_entry AS entry\n"

				"  LEFT OUTER JOIN ldb_attribute_values AS av\n"
				"    ON av.eid = entry.eid\n"

				"  WHERE entry.eid IN\n"
				"    (SELECT DISTINCT ldb_entry.eid\n"
				"       FROM ldb_entry\n"
				"       WHERE (ldb_entry.norm_dn GLOB('*,%q')\n"
				"       OR ldb_entry.norm_dn = '%q')\n"
				"       AND ldb_entry.eid IN\n"
				"         (%s)\n"
				"    )\n"

				"    %s\n"

				"  ORDER BY entry.eid ASC;",
				norm_basedn,
				norm_basedn,
				sqlfilter,
				attr_list);
		} else {
			query = lsqlite3_tprintf(local_ctx,
				"SELECT entry.eid,\n"
				"       entry.dn,\n"
				"       av.attr_name,\n"
				"       av.attr_value\n"
				"  FROM ldb_entry AS entry\n"

				"  LEFT OUTER JOIN ldb_attribute_values AS av\n"
				"    ON av.eid = entry.eid\n"

				"  WHERE entry.eid IN\n"
				"    (SELECT DISTINCT ldb_entry.eid\n"
				"       FROM ldb_entry\n"
				"       WHERE ldb_entry.eid IN\n"
				"         (%s)\n"
				"    )\n"

				"    %s\n"

				"  ORDER BY entry.eid ASC;",
				sqlfilter,
				attr_list);
		}

		break;
                
        case LDB_SCOPE_BASE:
                query = lsqlite3_tprintf(local_ctx,
                        "SELECT entry.eid,\n"
                        "       entry.dn,\n"
                        "       av.attr_name,\n"
                        "       av.attr_value\n"
                        "  FROM ldb_entry AS entry\n"

                        "  LEFT OUTER JOIN ldb_attribute_values AS av\n"
                        "    ON av.eid = entry.eid\n"

                        "  WHERE entry.eid IN\n"
                        "    (SELECT DISTINCT ldb_entry.eid\n"
                        "       FROM ldb_entry\n"
                        "       WHERE ldb_entry.norm_dn = '%q'\n"
                        "         AND ldb_entry.eid IN\n"
			"           (%s)\n"
                        "    )\n"

                        "    %s\n"

                        "  ORDER BY entry.eid ASC;",
			norm_basedn,
                        sqlfilter,
			attr_list);
                break;
                
        case LDB_SCOPE_ONELEVEL:
                query = lsqlite3_tprintf(local_ctx,
                        "SELECT entry.eid,\n"
                        "       entry.dn,\n"
                        "       av.attr_name,\n"
                        "       av.attr_value\n"
                        "  FROM ldb_entry AS entry\n"

                        "  LEFT OUTER JOIN ldb_attribute_values AS av\n"
                        "    ON av.eid = entry.eid\n"

                        "  WHERE entry.eid IN\n"
                        "    (SELECT DISTINCT ldb_entry.eid\n"
                        "       FROM ldb_entry\n"
			"       WHERE norm_dn GLOB('*,%q')\n"
			"         AND NOT norm_dn GLOB('*,*,%q')\n"
                        "         AND ldb_entry.eid IN\n(%s)\n"
                        "    )\n"

                        "    %s\n"

                        "  ORDER BY entry.eid ASC;",
                        norm_basedn,
                        norm_basedn,
                        sqlfilter,
			attr_list);
                break;
        }

        if (query == NULL) {
                ret = -1;
                goto failed;
        }

	/* printf ("%s\n", query); */

	msgs.msgs = NULL;
	msgs.count = 0;
	msgs.current_eid = 0;
	msgs.mem_ctx = local_ctx;

	ret = sqlite3_exec(lsqlite3->sqlite, query, lsqlite3_search_callback, &msgs, &errmsg);
	if (ret != SQLITE_OK) {
		if (errmsg) {
			printf("lsqlite3_search_bytree: Fatal Error: %s\n", errmsg);
			free(errmsg);
		}
		goto failed;
	}

	for (i = 0; i < msgs.count; i++) {
		msgs.msgs[i] = ldb_msg_canonicalize(module->ldb, msgs.msgs[i]);
		if (msgs.msgs[i] ==  NULL) goto failed;
	}

	*res = talloc_steal(module, msgs.msgs);
	ret = msgs.count;

	talloc_free(local_ctx);
	return ret;

/* If error, return error code; otherwise return number of results */
failed:
        talloc_free(local_ctx);
	return -1;
}

/* search for matching records, by expression */
static int lsqlite3_search(struct ldb_module * module, const struct ldb_dn *basedn,
			   enum ldb_scope scope, const char * expression,
			   const char * const *attrs, struct ldb_message *** res)
{
        struct ldb_parse_tree * tree;
        int ret;
        
        /* Handle tdb specials */
        if (ldb_dn_is_special(basedn)) {
#warning "handle tdb specials"
                return 0;
        }

#if 0 
/* (|(objectclass=*)(dn=*)) is  passed by the command line tool now instead */
        /* Handle the special case of requesting all */
        if (pExpression != NULL && *pExpression == '\0') {
                pExpression = "dn=*";
        }
#endif

        /* Parse the filter expression into a tree we can work with */
	if ((tree = ldb_parse_tree(module->ldb, expression)) == NULL) {
                return -1;
	}
        
        /* Now use the bytree function for the remainder of processing */
        ret = lsqlite3_search_bytree(module, basedn, scope, tree, attrs, res);
        
        /* Free the parse tree */
	talloc_free(tree);
        
        /* All done. */
        return ret;
}


/* add a record */
static int lsqlite3_add(struct ldb_module *module, const struct ldb_message *msg)
{
	TALLOC_CTX *local_ctx;
	struct lsqlite3_private *lsqlite3 = module->private_data;
        long long eid;
	char *dn, *ndn;
	char *errmsg;
	char *query;
	int rollback = 0;
	int ret;
	int i;
        
	/* create a local ctx */
	local_ctx = talloc_named(lsqlite3, 0, "lsqlite3_add local context");
	if (local_ctx == NULL) {
		return -1;
	}

        /* See if this is an ltdb special */
	if (ldb_dn_is_special(msg->dn)) {
		struct ldb_dn *c;

		c = ldb_dn_explode(local_ctx, "@SUBCLASSES");
		if (ldb_dn_compare(module->ldb, msg->dn, c) == 0) {
#warning "insert subclasses into object class tree"
			goto failed;
		}

		c = ldb_dn_explode(local_ctx, "@INDEXLIST");
		if (ldb_dn_compare(module->ldb, msg->dn, c) == 0) {
#warning "should we handle indexes somehow ?"
			goto failed;
		}

                /* Others are implicitly ignored */
                return 0;
	}

	/* create linearized and normalized dns */
	dn = ldb_dn_linearize(local_ctx, msg->dn);
	ndn = ldb_dn_linearize(local_ctx, ldb_dn_casefold(module->ldb, msg->dn));
	if (dn == NULL || ndn == NULL) goto failed;

	query = lsqlite3_tprintf(local_ctx,
        			   /* Begin the transaction */
				   "BEGIN EXCLUSIVE; "
				   /* Add new entry */
				   "INSERT OR ABORT INTO ldb_entry "
				   "('dn', 'norm_dn') "
				   "VALUES ('%q', '%q');",
				dn, ndn);
	if (query == NULL) goto failed;

	ret = sqlite3_exec(lsqlite3->sqlite, query, NULL, NULL, &errmsg);
	if (ret != SQLITE_OK) {
		if (errmsg) {
			printf("lsqlite3_add: exec error: %s\n", errmsg);
			free(errmsg);
		}
		lsqlite3_safe_rollback(lsqlite3->sqlite); 
		goto failed;
	}
	rollback = 1;

	eid = lsqlite3_get_eid_ndn(lsqlite3->sqlite, local_ctx, ndn);
	if (eid == -1) goto failed;

	for (i = 0; i < msg->num_elements; i++) {
		const struct ldb_message_element *el = &msg->elements[i];
		const struct ldb_attrib_handler *h;
		char *attr;
		int j;

		/* Get a case-folded copy of the attribute name */
		attr = ldb_casefold(local_ctx, el->name);
		if (attr == NULL) goto failed;

		h = ldb_attrib_handler(module->ldb, el->name);

		/* For each value of the specified attribute name... */
		for (j = 0; j < el->num_values; j++) {
			struct ldb_val value;
			char *insert;

			/* Get a canonicalised copy of the data */
			h->canonicalise_fn(module->ldb, local_ctx, &(el->values[j]), &value);
			if (value.data == NULL) goto failed;

			insert = lsqlite3_tprintf(local_ctx,
					"INSERT OR ROLLBACK INTO ldb_attribute_values "
					"('eid', 'attr_name', 'norm_attr_name',"
					" 'attr_value', 'norm_attr_value') "
					"VALUES ('%lld', '%q', '%q', '%q', '%q');",
					eid, el->name, attr,
					el->values[j].data, value.data);
			if (insert == NULL) goto failed;

			ret = sqlite3_exec(lsqlite3->sqlite, insert, NULL, NULL, &errmsg);
			if (ret != SQLITE_OK) {
				if (errmsg) {
					printf("lsqlite3_add: insert error: %s\n", errmsg);
					free(errmsg);
				}
				goto failed;
			}
		}
	}

	ret = sqlite3_exec(lsqlite3->sqlite, "COMMIT;", NULL, NULL, &errmsg);
	if (ret != SQLITE_OK) {
		if (errmsg) {
			printf("lsqlite3_add: commit error: %s\n", errmsg);
			free(errmsg);
		}
		goto failed;
	}

	talloc_free(local_ctx);
        return 0;

failed:
	if (rollback) lsqlite3_safe_rollback(lsqlite3->sqlite); 
	talloc_free(local_ctx);
	return -1;
}


/* modify a record */
static int lsqlite3_modify(struct ldb_module *module, const struct ldb_message *msg)
{
	TALLOC_CTX *local_ctx;
	struct lsqlite3_private *lsqlite3 = module->private_data;
        long long eid;
	char *errmsg;
	int rollback = 0;
	int ret;
	int i;
        
	/* create a local ctx */
	local_ctx = talloc_named(lsqlite3, 0, "lsqlite3_modify local context");
	if (local_ctx == NULL) {
		return -1;
	}

        /* See if this is an ltdb special */
	if (ldb_dn_is_special(msg->dn)) {
		struct ldb_dn *c;

		c = ldb_dn_explode(local_ctx, "@SUBCLASSES");
		if (ldb_dn_compare(module->ldb, msg->dn, c) == 0) {
#warning "modify subclasses into object class tree"
			goto failed;
		}

		c = ldb_dn_explode(local_ctx, "@INDEXLIST");
		if (ldb_dn_compare(module->ldb, msg->dn, c) == 0) {
#warning "should we handle indexes somehow ?"
			goto failed;
		}

                /* Others are implicitly ignored */
                return 0;
	}

	ret = sqlite3_exec(lsqlite3->sqlite, "BEGIN EXCLUSIVE;", NULL, NULL, &errmsg);
	if (ret != SQLITE_OK) {
		if (errmsg) {
			printf("lsqlite3_modify: error: %s\n", errmsg);
			free(errmsg);
		}
		goto failed;
	}
	rollback = 1;

	eid = lsqlite3_get_eid(module, msg->dn);
	if (eid == -1) {
		goto failed;
	}

	for (i = 0; i < msg->num_elements; i++) {
		const struct ldb_message_element *el = &msg->elements[i];
		const struct ldb_attrib_handler *h;
		int flags = el->flags & LDB_FLAG_MOD_MASK;
		char *attr;
		char *mod;
		int j;

		/* Get a case-folded copy of the attribute name */
		attr = ldb_casefold(local_ctx, el->name);
		if (attr == NULL) {
			goto failed;
		}

		h = ldb_attrib_handler(module->ldb, el->name);

		switch (flags) {

		case LDB_FLAG_MOD_REPLACE:
			
			/* remove all attributes before adding the replacements */
			mod = lsqlite3_tprintf(local_ctx,
						"DELETE FROM ldb_attribute_values "
						"WHERE eid = '%lld' "
						"AND norm_attr_name = '%q';",
						eid, attr);
			if (mod == NULL) goto failed;

			ret = sqlite3_exec(lsqlite3->sqlite, mod, NULL, NULL, &errmsg);
			if (ret != SQLITE_OK) {
				if (errmsg) {
					printf("lsqlite3_modify: error: %s\n", errmsg);
					free(errmsg);
				}
				goto failed;
                        }

			/* MISSING break is INTENTIONAL */

		case LDB_FLAG_MOD_ADD:
#warning "We should throw an error if no value is provided!"
			/* For each value of the specified attribute name... */
			for (j = 0; j < el->num_values; j++) {
				struct ldb_val value;

				/* Get a canonicalised copy of the data */
				h->canonicalise_fn(module->ldb, local_ctx, &(el->values[j]), &value);
				if (value.data == NULL) {
					goto failed;
				}

				mod = lsqlite3_tprintf(local_ctx,
					"INSERT OR ROLLBACK INTO ldb_attribute_values "
					"('eid', 'attr_name', 'norm_attr_name',"
					" 'attr_value', 'norm_attr_value') "
					"VALUES ('%lld', '%q', '%q', '%q', '%q');",
					eid, el->name, attr,
					el->values[j].data, value.data);

				if (mod == NULL) goto failed;

				ret = sqlite3_exec(lsqlite3->sqlite, mod, NULL, NULL, &errmsg);
				if (ret != SQLITE_OK) {
					if (errmsg) {
						printf("lsqlite3_modify: error: %s\n", errmsg);
						free(errmsg);
					}
					goto failed;
				}
			}

			break;

		case LDB_FLAG_MOD_DELETE:
#warning "We should throw an error if the attribute we are trying to delete does not exist!"
			if (el->num_values == 0) {
				mod = lsqlite3_tprintf(local_ctx,
							"DELETE FROM ldb_attribute_values "
							"WHERE eid = '%lld' "
							"AND norm_attr_name = '%q';",
							eid, attr);
				if (mod == NULL) goto failed;

				ret = sqlite3_exec(lsqlite3->sqlite, mod, NULL, NULL, &errmsg);
				if (ret != SQLITE_OK) {
					if (errmsg) {
						printf("lsqlite3_modify: error: %s\n", errmsg);
						free(errmsg);
					}
					goto failed;
                        	}
			}

			/* For each value of the specified attribute name... */
			for (j = 0; j < el->num_values; j++) {
				struct ldb_val value;

				/* Get a canonicalised copy of the data */
				h->canonicalise_fn(module->ldb, local_ctx, &(el->values[j]), &value);
				if (value.data == NULL) {
					goto failed;
				}

				mod = lsqlite3_tprintf(local_ctx,
					"DELETE FROM ldb_attribute_values "
					"WHERE eid = '%lld' "
					"AND norm_attr_name = '%q' "
					"AND norm_attr_value = '%q';",
					eid, attr, value.data);

				if (mod == NULL) goto failed;

				ret = sqlite3_exec(lsqlite3->sqlite, mod, NULL, NULL, &errmsg);
				if (ret != SQLITE_OK) {
					if (errmsg) {
						printf("lsqlite3_modify: error: %s\n", errmsg);
						free(errmsg);
					}
					goto failed;
				}
			}

			break;
		}
	}

	ret = sqlite3_exec(lsqlite3->sqlite, "COMMIT;", NULL, NULL, &errmsg);
	if (ret != SQLITE_OK) {
		if (errmsg) {
			printf("lsqlite3_modify: error: %s\n", errmsg);
			free(errmsg);
		}
		goto failed;
	}

	talloc_free(local_ctx);
        return 0;

failed:
	if (rollback) lsqlite3_safe_rollback(lsqlite3->sqlite); 
	talloc_free(local_ctx);
	return -1;
}

/* delete a record */
static int lsqlite3_delete(struct ldb_module *module, const struct ldb_dn *dn)
{
	TALLOC_CTX *local_ctx;
	struct lsqlite3_private *lsqlite3 = module->private_data;
        long long eid;
	char *errmsg;
	char *query;
	int ret;

	/* ignore ltdb specials */
	if (ldb_dn_is_special(dn)) {
		return 0;
	}

	/* create a local ctx */
	local_ctx = talloc_named(lsqlite3, 0, "lsqlite3_delete local context");
	if (local_ctx == NULL) {
		return -1;
	}

	eid = lsqlite3_get_eid(module, dn);
	if (eid == -1) goto failed;

	query = lsqlite3_tprintf(local_ctx,
        			   /* Begin the transaction */
				   "BEGIN EXCLUSIVE; "
				   /* Delete entry */
				   "DELETE FROM ldb_entry WHERE eid = %lld; "
				   /* Delete attributes */
				   "DELETE FROM ldb_attribute_values WHERE eid = %lld; "
				   /* Commit */
				   "COMMIT;",
				eid, eid);
	if (query == NULL) goto failed;

	ret = sqlite3_exec(lsqlite3->sqlite, query, NULL, NULL, &errmsg);
	if (ret != SQLITE_OK) {
		if (errmsg) {
			printf("lsqlite3_delete: error getting eid: %s\n", errmsg);
			free(errmsg);
		}
		lsqlite3_safe_rollback(lsqlite3->sqlite);
		goto failed;
	}

	talloc_free(local_ctx);
        return 0;

failed:
	talloc_free(local_ctx);
	return -1;
}

/* rename a record */
static int lsqlite3_rename(struct ldb_module *module, const struct ldb_dn *olddn, const struct ldb_dn *newdn)
{
	TALLOC_CTX *local_ctx;
	struct lsqlite3_private *lsqlite3 = module->private_data;
	char *new_dn, *new_cdn, *old_cdn;
	char *errmsg;
	char *query;
	int ret;

	/* ignore ltdb specials */
	if (ldb_dn_is_special(olddn) || ldb_dn_is_special(newdn)) {
		return 0;
	}

	/* create a local ctx */
	local_ctx = talloc_named(lsqlite3, 0, "lsqlite3_rename local context");
	if (local_ctx == NULL) {
		return -1;
	}

	/* create linearized and normalized dns */
	old_cdn = ldb_dn_linearize(local_ctx, ldb_dn_casefold(module->ldb, olddn));
	new_cdn = ldb_dn_linearize(local_ctx, ldb_dn_casefold(module->ldb, newdn));
	new_dn = ldb_dn_linearize(local_ctx, newdn);
	if (old_cdn == NULL || new_cdn == NULL || new_dn == NULL) goto failed;

	/* build the SQL query */
	query = lsqlite3_tprintf(local_ctx,
				 "UPDATE ldb_entry SET dn = '%q', norm_dn = '%q' "
				 "WHERE norm_dn = '%q';",
				 new_dn, new_cdn, old_cdn);
	if (query == NULL) goto failed;

	/* execute */
	ret = sqlite3_exec(lsqlite3->sqlite, query, NULL, NULL, &errmsg);
	if (ret != SQLITE_OK) {
		if (errmsg) {
			printf("lsqlite3_rename: sqlite3_exec error: %s\n", errmsg);
			free(errmsg);
		}
		goto failed;
	}

	/* clean up and exit */
	talloc_free(local_ctx);
        return 0;

failed:
	talloc_free(local_ctx);
	return -1;
}
/* return extended error information */
static const char *
lsqlite3_errstring(struct ldb_module *module)
{
	struct lsqlite3_private *   lsqlite3 = module->private_data;
        
	return sqlite3_errmsg(lsqlite3->sqlite);
}




/*
 * Static functions
 */

static int initialize(struct lsqlite3_private *lsqlite3, const char *url)
{
        int ret;
        long long queryInt;
        const char *pTail;
        sqlite3_stmt *stmt;
        const char *schema =       
                
                
                "CREATE TABLE ldb_info AS "
                "  SELECT 'LDB' AS database_type,"
                "         '1.0' AS version;"
                
                /*
                 * The entry table holds the information about an entry. 
                 * This table is used to obtain the EID of the entry and to 
                 * support scope=one and scope=base.  The parent and child
                 * table is included in the entry table since all the other
                 * attributes are dependent on EID.
                 */
                "CREATE TABLE ldb_entry "
                "("
                "  eid     INTEGER PRIMARY KEY AUTOINCREMENT,"
                "  dn      TEXT UNIQUE NOT NULL,"
		"  norm_dn TEXT UNIQUE NOT NULL"
                ");"
                

                "CREATE TABLE ldb_object_classes"
                "("
                "  class_name            TEXT PRIMARY KEY,"
                "  parent_class_name     TEXT,"
                "  tree_key              TEXT UNIQUE,"
                "  max_child_num         INTEGER DEFAULT 0"
                ");"
                
                /*
                 * We keep a full listing of attribute/value pairs here
                 */
                "CREATE TABLE ldb_attribute_values"
                "("
                "  eid             INTEGER REFERENCES ldb_entry,"
                "  attr_name       TEXT,"
                "  norm_attr_name  TEXT,"
                "  attr_value      TEXT,"
                "  norm_attr_value TEXT "
                ");"
                
               
                /*
                 * Indexes
                 */
                "CREATE INDEX ldb_attribute_values_eid_idx "
                "  ON ldb_attribute_values (eid);"
                
                "CREATE INDEX ldb_attribute_values_name_value_idx "
                "  ON ldb_attribute_values (attr_name, norm_attr_value);"
                
                

                /*
                 * Triggers
                 */
 
                "CREATE TRIGGER ldb_object_classes_insert_tr"
                "  AFTER INSERT"
                "  ON ldb_object_classes"
                "  FOR EACH ROW"
                "    BEGIN"
                "      UPDATE ldb_object_classes"
                "        SET tree_key = COALESCE(tree_key, "
                "              ("
                "                SELECT tree_key || "
                "                       (SELECT base160(max_child_num + 1)"
                "                                FROM ldb_object_classes"
                "                                WHERE class_name = "
                "                                      new.parent_class_name)"
                "                  FROM ldb_object_classes "
                "                  WHERE class_name = new.parent_class_name "
                "              ));"
                "      UPDATE ldb_object_classes "
                "        SET max_child_num = max_child_num + 1"
                "        WHERE class_name = new.parent_class_name;"
                "    END;"

                /*
                 * Table initialization
                 */

                "INSERT INTO ldb_object_classes "
                "    (class_name, tree_key) "
                "  VALUES "
                "    ('TOP', '0001');"

                ;
        
        /* Skip protocol indicator of url  */
        if (strncmp(url, "sqlite://", 9) != 0) {
                return SQLITE_MISUSE;
        }
        
        /* Update pointer to just after the protocol indicator */
        url += 9;
        
        /* Try to open the (possibly empty/non-existent) database */
        if ((ret = sqlite3_open(url, &lsqlite3->sqlite)) != SQLITE_OK) {
                return ret;
        }
        
        /* In case this is a new database, enable auto_vacuum */
        if (query_norows(lsqlite3, "PRAGMA auto_vacuum=1;") != 0) {
                        return -1;
        }
        
	/* DANGEROUS
        if (query_norows(lsqlite3, "PRAGMA synchronous = OFF;") != 0) {
                        return -1;
        }
	*/
        
        /* Establish a busy timeout of 30 seconds */
        if ((ret = sqlite3_busy_timeout(lsqlite3->sqlite,
                                        30000)) != SQLITE_OK) {
                return ret;
        }

        /* Create a function, callable from sql, to increment a tree_key */
        if ((ret =
             sqlite3_create_function(lsqlite3->sqlite,/* handle */
                                     "base160_next",  /* function name */
                                     1,               /* number of args */
                                     SQLITE_ANY,      /* preferred text type */
                                     NULL,            /* user data */
                                     base160next_sql, /* called func */
                                     NULL,            /* step func */
                                     NULL             /* final func */
                     )) != SQLITE_OK) {
                return ret;
        }

        /* Create a function, callable from sql, to convert int to base160 */
        if ((ret =
             sqlite3_create_function(lsqlite3->sqlite,/* handle */
                                     "base160",       /* function name */
                                     1,               /* number of args */
                                     SQLITE_ANY,      /* preferred text type */
                                     NULL,            /* user data */
                                     base160_sql,     /* called func */
                                     NULL,            /* step func */
                                     NULL             /* final func */
                     )) != SQLITE_OK) {
                return ret;
        }

        /* Begin a transaction */
        if ((ret = query_norows(lsqlite3, "BEGIN EXCLUSIVE;")) != 0) {
                        return ret;
        }
        
        /* Determine if this is a new database.  No tables means it is. */
        if (query_int(lsqlite3,
                      &queryInt,
                      "SELECT COUNT(*)\n"
                      "  FROM sqlite_master\n"
                      "  WHERE type = 'table';") != 0) {
                query_norows(lsqlite3, "ROLLBACK;");
                return -1;
        }
        
        if (queryInt == 0) {
                /*
                 * Create the database schema
                 */
                for (pTail = discard_const_p(char, schema);
                     pTail != NULL && *pTail != '\0';
                        ) {
                        
                        if ((ret = sqlite3_prepare(
                                     lsqlite3->sqlite,
                                     pTail,
                                     -1,
                                     &stmt,
                                     &pTail)) != SQLITE_OK ||
                            (ret = sqlite3_step(stmt)) != SQLITE_DONE ||
                            (ret = sqlite3_finalize(stmt)) != SQLITE_OK) {
                                
                                query_norows(lsqlite3, "ROLLBACK;");
                                (void) sqlite3_close(lsqlite3->sqlite);
                                return ret;
                        }
                }
        } else {
                /*
                 * Ensure that the database we opened is one of ours
                 */
                if (query_int(lsqlite3,
                              &queryInt,
                              "SELECT "
                              "  (SELECT COUNT(*) = 2"
                              "     FROM sqlite_master "
                              "     WHERE type = 'table' "
                              "       AND name IN "
                              "         ("
                              "           'ldb_entry', "
                              "           'ldb_object_classes' "
                              "         ) "
                              "  ) "
                              "  AND "
                              "  (SELECT 1 "
                              "     FROM ldb_info "
                              "     WHERE database_type = 'LDB' "
                              "       AND version = '1.0'"
                              "  );") != 0 ||
                    queryInt != 1) {
                        
                        /* It's not one that we created.  See ya! */
                        query_norows(lsqlite3, "ROLLBACK;");
                        (void) sqlite3_close(lsqlite3->sqlite);
                        return SQLITE_MISUSE;
                }
        }
        
        /*
         * Create a temporary table to hold attributes requested in the result
         * set of a search.
         */
        query_norows(lsqlite3, "DROP TABLE " RESULT_ATTR_TABLE ";\n");
        if ((ret =
             query_norows(lsqlite3,
                          "CREATE " TEMPTAB " TABLE " RESULT_ATTR_TABLE "\n"
                          " (\n"
                          "  attr_name TEXT PRIMARY KEY\n"
                          " );")) != 0) {
                query_norows(lsqlite3, "ROLLBACK;");
                return ret;
        }

        /* Commit the transaction */
        if ((ret = query_norows(lsqlite3, "COMMIT;")) != 0) {
                query_norows(lsqlite3, "ROLLBACK;");
                return ret;
        }
        
        return SQLITE_OK;
}

static int
destructor(void *p)
{
	struct lsqlite3_private *lsqlite3 = p;
        
	if (lsqlite3->sqlite) {
		sqlite3_close(lsqlite3->sqlite);
	}
	return 0;
}



/*
 * Table of operations for the sqlite3 backend
 */
static const struct ldb_module_ops lsqlite3_ops = {
	.name          = "sqlite",
	.search        = lsqlite3_search,
	.search_bytree = lsqlite3_search_bytree,
	.add_record    = lsqlite3_add,
	.modify_record = lsqlite3_modify,
	.delete_record = lsqlite3_delete,
	.rename_record = lsqlite3_rename,
	.named_lock    = lsqlite3_lock,
	.named_unlock  = lsqlite3_unlock,
	.errstring     = lsqlite3_errstring
};

/*
 * connect to the database
 */
int lsqlite3_connect(struct ldb_context *ldb,
		     const char *url, 
		     unsigned int flags, 
		     const char *options[])
{
	int                         i;
        int                         ret;
	struct lsqlite3_private *   lsqlite3 = NULL;
        
	lsqlite3 = talloc(ldb, struct lsqlite3_private);
	if (!lsqlite3) {
		goto failed;
	}
        
	lsqlite3->sqlite = NULL;
	lsqlite3->options = NULL;
        lsqlite3->lock_count = 0;
        
	ret = initialize(lsqlite3, url);
	if (ret != SQLITE_OK) {
		goto failed;
	}
        
	talloc_set_destructor(lsqlite3, destructor);
        
	ldb->modules = talloc(ldb, struct ldb_module);
	if (!ldb->modules) {
		goto failed;
	}
	ldb->modules->ldb = ldb;
	ldb->modules->prev = ldb->modules->next = NULL;
	ldb->modules->private_data = lsqlite3;
	ldb->modules->ops = &lsqlite3_ops;
        
	if (options) {
		/*
                 * take a copy of the options array, so we don't have to rely
                 * on the caller keeping it around (it might be dynamic)
                 */
		for (i=0;options[i];i++) ;
                
		lsqlite3->options = talloc_array(lsqlite3, char *, i+1);
		if (!lsqlite3->options) {
			goto failed;
		}
                
		for (i=0;options[i];i++) {
                        
			lsqlite3->options[i+1] = NULL;
			lsqlite3->options[i] =
                                talloc_strdup(lsqlite3->options, options[i]);
			if (!lsqlite3->options[i]) {
				goto failed;
			}
		}
	}
        
	return 0;
        
failed:
        if (lsqlite3->sqlite != NULL) {
                (void) sqlite3_close(lsqlite3->sqlite);
        }
	talloc_free(lsqlite3);
	return -1;
}