db.c

/*
 * Asterisk -- An open source telephony toolkit.
 *
 * Copyright (C) 1999 - 2005, Digium, Inc.
 *
 * Mark Spencer <markster@digium.com>
 *
 * See http://www.asterisk.org for more information about
 * the Asterisk project. Please do not directly contact
 * any of the maintainers of this project for assistance;
 * the project provides a web site, mailing lists and IRC
 * channels for your use.
 *
 * This program is free software, distributed under the terms of
 * the GNU General Public License Version 2. See the LICENSE file
 * at the top of the source tree.
 */

/*! \file
 *
 * \brief ASTdb Management
 *
 * \author Mark Spencer <markster@digium.com>
 *
 * \note DB3 is licensed under Sleepycat Public License and is thus incompatible
 * with GPL.  To avoid having to make another exception (and complicate
 * licensing even further) we elect to use DB1 which is BSD licensed
 */

/*** MODULEINFO
	<support_level>core</support_level>
 ***/

#include "asterisk.h"

#include "asterisk/_private.h"
#include "asterisk/paths.h"	/* use ast_config_AST_DB */
#include <sys/time.h>
#include <sys/types.h>
#include <sys/stat.h>
#include <unistd.h>
#include <signal.h>
#include <dirent.h>
#include <sqlite3.h>

#include "asterisk/channel.h"
#include "asterisk/file.h"
#include "asterisk/app.h"
#include "asterisk/dsp.h"
#include "asterisk/astdb.h"
#include "asterisk/cli.h"
#include "asterisk/utils.h"
#include "asterisk/manager.h"

/*** DOCUMENTATION
	<manager name="DBGet" language="en_US">
		<synopsis>
			Get DB Entry.
		</synopsis>
		<syntax>
			<xi:include xpointer="xpointer(/docs/manager[@name='Login']/syntax/parameter[@name='ActionID'])" />
			<parameter name="Family" required="true" />
			<parameter name="Key" required="true" />
		</syntax>
		<description>
		</description>
	</manager>
	<manager name="DBGetTree" language="en_US">
		<synopsis>
			Get DB entries, optionally at a particular family/key
		</synopsis>
		<syntax>
			<xi:include xpointer="xpointer(/docs/manager[@name='Login']/syntax/parameter[@name='ActionID'])" />
			<parameter name="Family" required="false" />
			<parameter name="Key" required="false" />
		</syntax>
		<description>
		</description>
	</manager>
	<manager name="DBPut" language="en_US">
		<synopsis>
			Put DB entry.
		</synopsis>
		<syntax>
			<xi:include xpointer="xpointer(/docs/manager[@name='Login']/syntax/parameter[@name='ActionID'])" />
			<parameter name="Family" required="true" />
			<parameter name="Key" required="true" />
			<parameter name="Val" />
		</syntax>
		<description>
		</description>
	</manager>
	<manager name="DBDel" language="en_US">
		<synopsis>
			Delete DB entry.
		</synopsis>
		<syntax>
			<xi:include xpointer="xpointer(/docs/manager[@name='Login']/syntax/parameter[@name='ActionID'])" />
			<parameter name="Family" required="true" />
			<parameter name="Key" required="true" />
		</syntax>
		<description>
		</description>
	</manager>
	<manager name="DBDelTree" language="en_US">
		<synopsis>
			Delete DB Tree.
		</synopsis>
		<syntax>
			<xi:include xpointer="xpointer(/docs/manager[@name='Login']/syntax/parameter[@name='ActionID'])" />
			<parameter name="Family" required="true" />
			<parameter name="Key" />
		</syntax>
		<description>
		</description>
	</manager>
 ***/

#define MAX_DB_FIELD 256
AST_MUTEX_DEFINE_STATIC(dblock);
static ast_cond_t dbcond;
static sqlite3 *astdb;
static pthread_t syncthread;
static int doexit;
static int dosync;

static void db_sync(void);

#define DEFINE_SQL_STATEMENT(stmt,sql) static sqlite3_stmt *stmt; \
	const char stmt##_sql[] = sql;

DEFINE_SQL_STATEMENT(put_stmt, "INSERT OR REPLACE INTO astdb (key, value) VALUES (?, ?)")
DEFINE_SQL_STATEMENT(get_stmt, "SELECT value FROM astdb WHERE key=?")
DEFINE_SQL_STATEMENT(del_stmt, "DELETE FROM astdb WHERE key=?")
DEFINE_SQL_STATEMENT(deltree_stmt, "DELETE FROM astdb WHERE key || '/' LIKE ? || '/' || '%'")
DEFINE_SQL_STATEMENT(deltree_all_stmt, "DELETE FROM astdb")
DEFINE_SQL_STATEMENT(gettree_stmt, "SELECT key, value FROM astdb WHERE key || '/' LIKE ? || '/' || '%' ORDER BY key")
DEFINE_SQL_STATEMENT(gettree_all_stmt, "SELECT key, value FROM astdb ORDER BY key")
DEFINE_SQL_STATEMENT(showkey_stmt, "SELECT key, value FROM astdb WHERE key LIKE '%' || '/' || ? ORDER BY key")
DEFINE_SQL_STATEMENT(create_astdb_stmt, "CREATE TABLE IF NOT EXISTS astdb(key VARCHAR(256), value VARCHAR(256), PRIMARY KEY(key))")

/* This query begs an explanation:
 *
 * First, the parameter binding syntax used here is slightly different than the other
 * queries in that we use a numbered parameter so that we can bind once and get the same
 * value substituted multiple times within the executed query.
 *
 * Second, the key comparison is being used to find all keys that are lexicographically
 * greater than the provided key, but less than the provided key with a high (but
 * invalid) Unicode codepoint appended to it. This will give us all keys in the database
 * that have 'key' as a prefix and performs much better than the equivalent "LIKE key ||
 * '%'" operation.
 */
DEFINE_SQL_STATEMENT(gettree_prefix_stmt, "SELECT key, value FROM astdb WHERE key > ?1 AND key <= ?1 || X'ffff'")

static int init_stmt(sqlite3_stmt **stmt, const char *sql, size_t len)
{
	ast_mutex_lock(&dblock);
	if (sqlite3_prepare(astdb, sql, len, stmt, NULL) != SQLITE_OK) {
		ast_log(LOG_WARNING, "Couldn't prepare statement '%s': %s\n", sql, sqlite3_errmsg(astdb));
		ast_mutex_unlock(&dblock);
		return -1;
	}
	ast_mutex_unlock(&dblock);

	return 0;
}

/*! \internal
 * \brief Clean up the prepared SQLite3 statement
 * \note dblock should already be locked prior to calling this method
 */
static int clean_stmt(sqlite3_stmt **stmt, const char *sql)
{
	if (sqlite3_finalize(*stmt) != SQLITE_OK) {
		ast_log(LOG_WARNING, "Couldn't finalize statement '%s': %s\n", sql, sqlite3_errmsg(astdb));
		*stmt = NULL;
		return -1;
	}
	*stmt = NULL;
	return 0;
}

/*! \internal
 * \brief Clean up all prepared SQLite3 statements
 * \note dblock should already be locked prior to calling this method
 */
static void clean_statements(void)
{
	clean_stmt(&get_stmt, get_stmt_sql);
	clean_stmt(&del_stmt, del_stmt_sql);
	clean_stmt(&deltree_stmt, deltree_stmt_sql);
	clean_stmt(&deltree_all_stmt, deltree_all_stmt_sql);
	clean_stmt(&gettree_stmt, gettree_stmt_sql);
	clean_stmt(&gettree_all_stmt, gettree_all_stmt_sql);
	clean_stmt(&gettree_prefix_stmt, gettree_prefix_stmt_sql);
	clean_stmt(&showkey_stmt, showkey_stmt_sql);
	clean_stmt(&put_stmt, put_stmt_sql);
	clean_stmt(&create_astdb_stmt, create_astdb_stmt_sql);
}

static int init_statements(void)
{
	/* Don't initialize create_astdb_statement here as the astdb table needs to exist
	 * brefore these statements can be initialized */
	return init_stmt(&get_stmt, get_stmt_sql, sizeof(get_stmt_sql))
	|| init_stmt(&del_stmt, del_stmt_sql, sizeof(del_stmt_sql))
	|| init_stmt(&deltree_stmt, deltree_stmt_sql, sizeof(deltree_stmt_sql))
	|| init_stmt(&deltree_all_stmt, deltree_all_stmt_sql, sizeof(deltree_all_stmt_sql))
	|| init_stmt(&gettree_stmt, gettree_stmt_sql, sizeof(gettree_stmt_sql))
	|| init_stmt(&gettree_all_stmt, gettree_all_stmt_sql, sizeof(gettree_all_stmt_sql))
	|| init_stmt(&gettree_prefix_stmt, gettree_prefix_stmt_sql, sizeof(gettree_prefix_stmt_sql))
	|| init_stmt(&showkey_stmt, showkey_stmt_sql, sizeof(showkey_stmt_sql))
	|| init_stmt(&put_stmt, put_stmt_sql, sizeof(put_stmt_sql));
}

static int convert_bdb_to_sqlite3(void)
{
	char *cmd;
	int res;

	res = ast_asprintf(&cmd, "%s/astdb2sqlite3 '%s'\n", ast_config_AST_SBIN_DIR, ast_config_AST_DB);
	if (0 <= res) {
		res = ast_safe_system(cmd);
		ast_free(cmd);
	}

	return res;
}

static int db_create_astdb(void)
{
	int res = 0;

	if (!create_astdb_stmt) {
		init_stmt(&create_astdb_stmt, create_astdb_stmt_sql, sizeof(create_astdb_stmt_sql));
	}

	ast_mutex_lock(&dblock);
	if (sqlite3_step(create_astdb_stmt) != SQLITE_DONE) {
		ast_log(LOG_WARNING, "Couldn't create astdb table: %s\n", sqlite3_errmsg(astdb));
		res = -1;
	}
	sqlite3_reset(create_astdb_stmt);
	db_sync();
	ast_mutex_unlock(&dblock);

	return res;
}

static int db_open(void)
{
	char *dbname;
	struct stat dont_care;

	if (!(dbname = ast_alloca(strlen(ast_config_AST_DB) + sizeof(".sqlite3")))) {
		return -1;
	}
	strcpy(dbname, ast_config_AST_DB);
	strcat(dbname, ".sqlite3");

	if (stat(dbname, &dont_care) && !stat(ast_config_AST_DB, &dont_care)) {
		if (convert_bdb_to_sqlite3()) {
			ast_log(LOG_ERROR, "*** Database conversion failed!\n");
			ast_log(LOG_ERROR, "*** Asterisk now uses SQLite3 for its internal\n");
			ast_log(LOG_ERROR, "*** database. Conversion from the old astdb\n");
			ast_log(LOG_ERROR, "*** failed. Most likely the astdb2sqlite3 utility\n");
			ast_log(LOG_ERROR, "*** was not selected for build. To convert the\n");
			ast_log(LOG_ERROR, "*** old astdb, please delete '%s'\n", dbname);
			ast_log(LOG_ERROR, "*** and re-run 'make menuselect' and select astdb2sqlite3\n");
			ast_log(LOG_ERROR, "*** in the Utilities section, then 'make && make install'.\n");
			ast_log(LOG_ERROR, "*** It is also imperative that the user under which\n");
			ast_log(LOG_ERROR, "*** Asterisk runs have write permission to the directory\n");
			ast_log(LOG_ERROR, "*** where the database resides.\n");
			sleep(5);
		} else {
			ast_log(LOG_NOTICE, "Database conversion succeeded!\n");
		}
	}

	ast_mutex_lock(&dblock);
	if (sqlite3_open(dbname, &astdb) != SQLITE_OK) {
		ast_log(LOG_WARNING, "Unable to open Asterisk database '%s': %s\n", dbname, sqlite3_errmsg(astdb));
		sqlite3_close(astdb);
		ast_mutex_unlock(&dblock);
		return -1;
	}

	ast_mutex_unlock(&dblock);

	return 0;
}

static int db_init(void)
{
	if (astdb) {
		return 0;
	}

	if (db_open() || db_create_astdb() || init_statements()) {
		return -1;
	}

	return 0;
}

/* We purposely don't lock around the sqlite3 call because the transaction
 * calls will be called with the database lock held. For any other use, make
 * sure to take the dblock yourself. */
static int db_execute_sql(const char *sql, int (*callback)(void *, int, char **, char **), void *arg)
{
	char *errmsg = NULL;
	int res =0;

	if (sqlite3_exec(astdb, sql, callback, arg, &errmsg) != SQLITE_OK) {
		ast_log(LOG_WARNING, "Error executing SQL (%s): %s\n", sql, errmsg);
		sqlite3_free(errmsg);
		res = -1;
	}

	return res;
}

static int ast_db_begin_transaction(void)
{
	return db_execute_sql("BEGIN TRANSACTION", NULL, NULL);
}

static int ast_db_commit_transaction(void)
{
	return db_execute_sql("COMMIT", NULL, NULL);
}

static int ast_db_rollback_transaction(void)
{
	return db_execute_sql("ROLLBACK", NULL, NULL);
}

int ast_db_put(const char *family, const char *key, const char *value)
{
	char fullkey[MAX_DB_FIELD];
	size_t fullkey_len;
	int res = 0;

	if (strlen(family) + strlen(key) + 2 > sizeof(fullkey) - 1) {
		ast_log(LOG_WARNING, "Family and key length must be less than %zu bytes\n", sizeof(fullkey) - 3);
		return -1;
	}

	fullkey_len = snprintf(fullkey, sizeof(fullkey), "/%s/%s", family, key);

	ast_mutex_lock(&dblock);
	if (sqlite3_bind_text(put_stmt, 1, fullkey, fullkey_len, SQLITE_STATIC) != SQLITE_OK) {
		ast_log(LOG_WARNING, "Couldn't bind key to stmt: %s\n", sqlite3_errmsg(astdb));
		res = -1;
	} else if (sqlite3_bind_text(put_stmt, 2, value, -1, SQLITE_STATIC) != SQLITE_OK) {
		ast_log(LOG_WARNING, "Couldn't bind value to stmt: %s\n", sqlite3_errmsg(astdb));
		res = -1;
	} else if (sqlite3_step(put_stmt) != SQLITE_DONE) {
		ast_log(LOG_WARNING, "Couldn't execute statement: %s\n", sqlite3_errmsg(astdb));
		res = -1;
	}

	sqlite3_reset(put_stmt);
	db_sync();
	ast_mutex_unlock(&dblock);

	return res;
}

/*!
 * \internal
 * \brief Get key value specified by family/key.
 *
 * Gets the value associated with the specified \a family and \a key, and
 * stores it, either into the fixed sized buffer specified by \a buffer
 * and \a bufferlen, or as a heap allocated string if \a bufferlen is -1.
 *
 * \note If \a bufferlen is -1, \a buffer points to heap allocated memory
 *       and must be freed by calling ast_free().
 *
 * \retval -1 An error occurred
 * \retval 0 Success
 */
static int db_get_common(const char *family, const char *key, char **buffer, int bufferlen)
{
	const unsigned char *result;
	char fullkey[MAX_DB_FIELD];
	size_t fullkey_len;
	int res = 0;

	if (strlen(family) + strlen(key) + 2 > sizeof(fullkey) - 1) {
		ast_log(LOG_WARNING, "Family and key length must be less than %zu bytes\n", sizeof(fullkey) - 3);
		return -1;
	}

	fullkey_len = snprintf(fullkey, sizeof(fullkey), "/%s/%s", family, key);

	ast_mutex_lock(&dblock);
	if (sqlite3_bind_text(get_stmt, 1, fullkey, fullkey_len, SQLITE_STATIC) != SQLITE_OK) {
		ast_log(LOG_WARNING, "Couldn't bind key to stmt: %s\n", sqlite3_errmsg(astdb));
		res = -1;
	} else if (sqlite3_step(get_stmt) != SQLITE_ROW) {
		ast_debug(1, "Unable to find key '%s' in family '%s'\n", key, family);
		res = -1;
	} else if (!(result = sqlite3_column_text(get_stmt, 0))) {
		ast_log(LOG_WARNING, "Couldn't get value\n");
		res = -1;
	} else {
		const char *value = (const char *) result;

		if (bufferlen == -1) {
			*buffer = ast_strdup(value);
		} else {
			ast_copy_string(*buffer, value, bufferlen);
		}
	}
	sqlite3_reset(get_stmt);
	ast_mutex_unlock(&dblock);

	return res;
}

int ast_db_get(const char *family, const char *key, char *value, int valuelen)
{
	ast_assert(value != NULL);

	/* Make sure we initialize */
	value[0] = 0;

	return db_get_common(family, key, &value, valuelen);
}

int ast_db_get_allocated(const char *family, const char *key, char **out)
{
	*out = NULL;

	return db_get_common(family, key, out, -1);
}

int ast_db_del(const char *family, const char *key)
{
	char fullkey[MAX_DB_FIELD];
	size_t fullkey_len;
	int res = 0;

	if (strlen(family) + strlen(key) + 2 > sizeof(fullkey) - 1) {
		ast_log(LOG_WARNING, "Family and key length must be less than %zu bytes\n", sizeof(fullkey) - 3);
		return -1;
	}

	fullkey_len = snprintf(fullkey, sizeof(fullkey), "/%s/%s", family, key);

	ast_mutex_lock(&dblock);
	if (sqlite3_bind_text(del_stmt, 1, fullkey, fullkey_len, SQLITE_STATIC) != SQLITE_OK) {
		ast_log(LOG_WARNING, "Couldn't bind key to stmt: %s\n", sqlite3_errmsg(astdb));
		res = -1;
	} else if (sqlite3_step(del_stmt) != SQLITE_DONE) {
		ast_debug(1, "Unable to find key '%s' in family '%s'\n", key, family);
		res = -1;
	}
	sqlite3_reset(del_stmt);
	db_sync();
	ast_mutex_unlock(&dblock);

	return res;
}

int ast_db_del2(const char *family, const char *key)
{
	char fullkey[MAX_DB_FIELD];
	char tmp[1];
	size_t fullkey_len;
	int mres, res = 0;

	if (strlen(family) + strlen(key) + 2 > sizeof(fullkey) - 1) {
		ast_log(LOG_WARNING, "Family and key length must be less than %zu bytes\n", sizeof(fullkey) - 3);
		return -1;
	}

	fullkey_len = snprintf(fullkey, sizeof(fullkey), "/%s/%s", family, key);

	ast_mutex_lock(&dblock);
	if (ast_db_get(family, key, tmp, sizeof(tmp))) {
		ast_log(LOG_WARNING, "AstDB key %s does not exist\n", fullkey);
		res = -1;
	} else if (sqlite3_bind_text(del_stmt, 1, fullkey, fullkey_len, SQLITE_STATIC) != SQLITE_OK) {
		ast_log(LOG_WARNING, "Couldn't bind key to stmt: %s\n", sqlite3_errmsg(astdb));
		res = -1;
	} else if ((mres = sqlite3_step(del_stmt) != SQLITE_DONE)) {
		ast_log(LOG_WARNING, "AstDB error (%s): %s\n", fullkey, sqlite3_errstr(mres));
		res = -1;
	}
	sqlite3_reset(del_stmt);
	db_sync();
	ast_mutex_unlock(&dblock);

	return res;
}

int ast_db_deltree(const char *family, const char *keytree)
{
	sqlite3_stmt *stmt = deltree_stmt;
	char prefix[MAX_DB_FIELD];
	int res = 0;

	if (!ast_strlen_zero(family)) {
		if (!ast_strlen_zero(keytree)) {
			/* Family and key tree */
			snprintf(prefix, sizeof(prefix), "/%s/%s", family, keytree);
		} else {
			/* Family only */
			snprintf(prefix, sizeof(prefix), "/%s", family);
		}
	} else {
		prefix[0] = '\0';
		stmt = deltree_all_stmt;
	}

	ast_mutex_lock(&dblock);
	if (!ast_strlen_zero(prefix) && (sqlite3_bind_text(stmt, 1, prefix, -1, SQLITE_STATIC) != SQLITE_OK)) {
		ast_log(LOG_WARNING, "Couldn't bind %s to stmt: %s\n", prefix, sqlite3_errmsg(astdb));
		res = -1;
	} else if (sqlite3_step(stmt) != SQLITE_DONE) {
		ast_log(LOG_WARNING, "Couldn't execute stmt: %s\n", sqlite3_errmsg(astdb));
		res = -1;
	}
	res = sqlite3_changes(astdb);
	sqlite3_reset(stmt);
	db_sync();
	ast_mutex_unlock(&dblock);

	return res;
}

static struct ast_db_entry *db_gettree_common(sqlite3_stmt *stmt)
{
	struct ast_db_entry *head = NULL, *prev = NULL, *cur;

	while (sqlite3_step(stmt) == SQLITE_ROW) {
		const char *key, *value;
		size_t key_len, value_len;

		key   = (const char *) sqlite3_column_text(stmt, 0);
		value = (const char *) sqlite3_column_text(stmt, 1);

		if (!key || !value) {
			break;
		}

		key_len = strlen(key);
		value_len = strlen(value);

		cur = ast_malloc(sizeof(*cur) + key_len + value_len + 2);
		if (!cur) {
			break;
		}

		cur->next = NULL;
		cur->key = cur->data + value_len + 1;
		memcpy(cur->data, value, value_len + 1);
		memcpy(cur->key, key, key_len + 1);

		if (prev) {
			prev->next = cur;
		} else {
			head = cur;
		}
		prev = cur;
	}

	return head;
}

struct ast_db_entry *ast_db_gettree(const char *family, const char *keytree)
{
	char prefix[MAX_DB_FIELD];
	sqlite3_stmt *stmt = gettree_stmt;
	size_t res = 0;
	struct ast_db_entry *ret;

	if (!ast_strlen_zero(family)) {
		if (!ast_strlen_zero(keytree)) {
			/* Family and key tree */
			res = snprintf(prefix, sizeof(prefix), "/%s/%s", family, keytree);
		} else {
			/* Family only */
			res = snprintf(prefix, sizeof(prefix), "/%s", family);
		}

		if (res >= sizeof(prefix)) {
			ast_log(LOG_WARNING, "Requested prefix is too long: %s\n", keytree);
			return NULL;
		}
	} else {
		prefix[0] = '\0';
		stmt = gettree_all_stmt;
	}

	ast_mutex_lock(&dblock);
	if (res && (sqlite3_bind_text(stmt, 1, prefix, res, SQLITE_STATIC) != SQLITE_OK)) {
		ast_log(LOG_WARNING, "Could not bind %s to stmt: %s\n", prefix, sqlite3_errmsg(astdb));
		sqlite3_reset(stmt);
		ast_mutex_unlock(&dblock);
		return NULL;
	}

	ret = db_gettree_common(stmt);
	sqlite3_reset(stmt);
	ast_mutex_unlock(&dblock);

	return ret;
}

struct ast_db_entry *ast_db_gettree_by_prefix(const char *family, const char *key_prefix)
{
	char prefix[MAX_DB_FIELD];
	size_t res;
	struct ast_db_entry *ret;

	res = snprintf(prefix, sizeof(prefix), "/%s/%s", family, key_prefix);
	if (res >= sizeof(prefix)) {
		ast_log(LOG_WARNING, "Requested key prefix is too long: %s\n", key_prefix);
		return NULL;
	}

	ast_mutex_lock(&dblock);
	if (sqlite3_bind_text(gettree_prefix_stmt, 1, prefix, res, SQLITE_STATIC) != SQLITE_OK) {
		ast_log(LOG_WARNING, "Could not bind %s to stmt: %s\n", prefix, sqlite3_errmsg(astdb));
		sqlite3_reset(gettree_prefix_stmt);
		ast_mutex_unlock(&dblock);
		return NULL;
	}

	ret = db_gettree_common(gettree_prefix_stmt);
	sqlite3_reset(gettree_prefix_stmt);
	ast_mutex_unlock(&dblock);

	return ret;
}

void ast_db_freetree(struct ast_db_entry *dbe)
{
	struct ast_db_entry *last;
	while (dbe) {
		last = dbe;
		dbe = dbe->next;
		ast_free(last);
	}
}

static char *handle_cli_database_put(struct ast_cli_entry *e, int cmd, struct ast_cli_args *a)
{
	int res;

	switch (cmd) {
	case CLI_INIT:
		e->command = "database put";
		e->usage =
			"Usage: database put <family> <key> <value>\n"
			"       Adds or updates an entry in the Asterisk database for\n"
			"       a given family, key, and value.\n";
		return NULL;
	case CLI_GENERATE:
		return NULL;
	}

	if (a->argc != 5)
		return CLI_SHOWUSAGE;
	res = ast_db_put(a->argv[2], a->argv[3], a->argv[4]);
	if (res)  {
		ast_cli(a->fd, "Failed to update entry\n");
	} else {
		ast_cli(a->fd, "Updated database successfully\n");
	}
	return CLI_SUCCESS;
}

static char *handle_cli_database_get(struct ast_cli_entry *e, int cmd, struct ast_cli_args *a)
{
	int res;
	char tmp[MAX_DB_FIELD];

	switch (cmd) {
	case CLI_INIT:
		e->command = "database get";
		e->usage =
			"Usage: database get <family> <key>\n"
			"       Retrieves an entry in the Asterisk database for a given\n"
			"       family and key.\n";
		return NULL;
	case CLI_GENERATE:
		return NULL;
	}

	if (a->argc != 4)
		return CLI_SHOWUSAGE;
	res = ast_db_get(a->argv[2], a->argv[3], tmp, sizeof(tmp));
	if (res) {
		ast_cli(a->fd, "Database entry not found.\n");
	} else {
		ast_cli(a->fd, "Value: %s\n", tmp);
	}
	return CLI_SUCCESS;
}

static char *handle_cli_database_del(struct ast_cli_entry *e, int cmd, struct ast_cli_args *a)
{
	int res;

	switch (cmd) {
	case CLI_INIT:
		e->command = "database del";
		e->usage =
			"Usage: database del <family> <key>\n"
			"       Deletes an entry in the Asterisk database for a given\n"
			"       family and key.\n";
		return NULL;
	case CLI_GENERATE:
		return NULL;
	}

	if (a->argc != 4)
		return CLI_SHOWUSAGE;
	res = ast_db_del2(a->argv[2], a->argv[3]);
	if (res) {
		ast_cli(a->fd, "Database entry could not be removed.\n");
	} else {
		ast_cli(a->fd, "Database entry removed.\n");
	}
	return CLI_SUCCESS;
}

static char *handle_cli_database_deltree(struct ast_cli_entry *e, int cmd, struct ast_cli_args *a)
{
	int num_deleted;

	switch (cmd) {
	case CLI_INIT:
		e->command = "database deltree";
		e->usage =
			"Usage: database deltree <family> [keytree]\n"
			"   OR: database deltree <family>[/keytree]\n"
			"       Deletes a family or specific keytree within a family\n"
			"       in the Asterisk database.  The two arguments may be\n"
			"       separated by either a space or a slash.\n";
		return NULL;
	case CLI_GENERATE:
		return NULL;
	}

	if ((a->argc < 3) || (a->argc > 4))
		return CLI_SHOWUSAGE;
	if (a->argc == 4) {
		num_deleted = ast_db_deltree(a->argv[2], a->argv[3]);
	} else {
		num_deleted = ast_db_deltree(a->argv[2], NULL);
	}
	if (num_deleted < 0) {
		ast_cli(a->fd, "Database unavailable.\n");
	} else if (num_deleted == 0) {
		ast_cli(a->fd, "Database entries do not exist.\n");
	} else {
		ast_cli(a->fd, "%d database entries removed.\n",num_deleted);
	}
	return CLI_SUCCESS;
}

static char *handle_cli_database_show(struct ast_cli_entry *e, int cmd, struct ast_cli_args *a)
{
	char prefix[MAX_DB_FIELD];
	int counter = 0;
	sqlite3_stmt *stmt = gettree_stmt;

	switch (cmd) {
	case CLI_INIT:
		e->command = "database show";
		e->usage =
			"Usage: database show [family [keytree]]\n"
			"   OR: database show [family[/keytree]]\n"
			"       Shows Asterisk database contents, optionally restricted\n"
			"       to a given family, or family and keytree. The two arguments\n"
			"       may be separated either by a space or by a slash.\n";
		return NULL;
	case CLI_GENERATE:
		return NULL;
	}

	if (a->argc == 4) {
		/* Family and key tree */
		snprintf(prefix, sizeof(prefix), "/%s/%s", a->argv[2], a->argv[3]);
	} else if (a->argc == 3) {
		/* Family only */
		snprintf(prefix, sizeof(prefix), "/%s", a->argv[2]);
	} else if (a->argc == 2) {
		/* Neither */
		prefix[0] = '\0';
		stmt = gettree_all_stmt;

	} else {
		return CLI_SHOWUSAGE;
	}

	ast_mutex_lock(&dblock);
	if (!ast_strlen_zero(prefix) && (sqlite3_bind_text(stmt, 1, prefix, -1, SQLITE_STATIC) != SQLITE_OK)) {
		ast_log(LOG_WARNING, "Couldn't bind %s to stmt: %s\n", prefix, sqlite3_errmsg(astdb));
		sqlite3_reset(stmt);
		ast_mutex_unlock(&dblock);
		return NULL;
	}

	while (sqlite3_step(stmt) == SQLITE_ROW) {
		const char *key_s, *value_s;
		if (!(key_s = (const char *) sqlite3_column_text(stmt, 0))) {
			ast_log(LOG_WARNING, "Skipping invalid key!\n");
			continue;
		}
		if (!(value_s = (const char *) sqlite3_column_text(stmt, 1))) {
			ast_log(LOG_WARNING, "Skipping invalid value!\n");
			continue;
		}
		++counter;
		ast_cli(a->fd, "%-50s: %-25s\n", key_s, value_s);
	}

	sqlite3_reset(stmt);
	ast_mutex_unlock(&dblock);

	ast_cli(a->fd, "%d results found.\n", counter);
	return CLI_SUCCESS;
}

static char *handle_cli_database_showkey(struct ast_cli_entry *e, int cmd, struct ast_cli_args *a)
{
	int counter = 0;

	switch (cmd) {
	case CLI_INIT:
		e->command = "database showkey";
		e->usage =
			"Usage: database showkey <keytree>\n"
			"       Shows Asterisk database contents, restricted to a given key.\n";
		return NULL;
	case CLI_GENERATE:
		return NULL;
	}

	if (a->argc != 3) {
		return CLI_SHOWUSAGE;
	}

	ast_mutex_lock(&dblock);
	if (!ast_strlen_zero(a->argv[2]) && (sqlite3_bind_text(showkey_stmt, 1, a->argv[2], -1, SQLITE_STATIC) != SQLITE_OK)) {
		ast_log(LOG_WARNING, "Couldn't bind %s to stmt: %s\n", a->argv[2], sqlite3_errmsg(astdb));
		sqlite3_reset(showkey_stmt);
		ast_mutex_unlock(&dblock);
		return NULL;
	}

	while (sqlite3_step(showkey_stmt) == SQLITE_ROW) {
		const char *key_s, *value_s;
		if (!(key_s = (const char *) sqlite3_column_text(showkey_stmt, 0))) {
			break;
		}
		if (!(value_s = (const char *) sqlite3_column_text(showkey_stmt, 1))) {
			break;
		}
		++counter;
		ast_cli(a->fd, "%-50s: %-25s\n", key_s, value_s);
	}
	sqlite3_reset(showkey_stmt);
	ast_mutex_unlock(&dblock);

	ast_cli(a->fd, "%d results found.\n", counter);
	return CLI_SUCCESS;
}

static int display_results(void *arg, int columns, char **values, char **colnames)
{
	struct ast_cli_args *a = arg;
	size_t x;

	for (x = 0; x < columns; x++) {
		ast_cli(a->fd, "%-5s: %-50s\n", colnames[x], values[x]);
	}
	ast_cli(a->fd, "\n");

	return 0;
}

static char *handle_cli_database_query(struct ast_cli_entry *e, int cmd, struct ast_cli_args *a)
{

	switch (cmd) {
	case CLI_INIT:
		e->command = "database query";
		e->usage =
			"Usage: database query \"<SQL Statement>\"\n"
			"       Run a user-specified SQL query on the database. Be careful.\n";
		return NULL;
	case CLI_GENERATE:
		return NULL;
	}

	if (a->argc != 3) {
		return CLI_SHOWUSAGE;
	}

	ast_mutex_lock(&dblock);
	db_execute_sql(a->argv[2], display_results, a);
	db_sync(); /* Go ahead and sync the db in case they write */
	ast_mutex_unlock(&dblock);

	return CLI_SUCCESS;
}

static struct ast_cli_entry cli_database[] = {
	AST_CLI_DEFINE(handle_cli_database_show,    "Shows database contents"),
	AST_CLI_DEFINE(handle_cli_database_showkey, "Shows database contents"),
	AST_CLI_DEFINE(handle_cli_database_get,     "Gets database value"),
	AST_CLI_DEFINE(handle_cli_database_put,     "Adds/updates database value"),
	AST_CLI_DEFINE(handle_cli_database_del,     "Removes database key/value"),
	AST_CLI_DEFINE(handle_cli_database_deltree, "Removes database keytree/values"),
	AST_CLI_DEFINE(handle_cli_database_query,   "Run a user-specified query on the astdb"),
};

static int manager_dbput(struct mansession *s, const struct message *m)
{
	const char *family = astman_get_header(m, "Family");
	const char *key = astman_get_header(m, "Key");
	const char *val = astman_get_header(m, "Val");
	int res;

	if (ast_strlen_zero(family)) {
		astman_send_error(s, m, "No family specified");
		return 0;
	}
	if (ast_strlen_zero(key)) {
		astman_send_error(s, m, "No key specified");
		return 0;
	}

	res = ast_db_put(family, key, S_OR(val, ""));
	if (res) {
		astman_send_error(s, m, "Failed to update entry");
	} else {
		astman_send_ack(s, m, "Updated database successfully");
	}
	return 0;
}

static int manager_dbget(struct mansession *s, const struct message *m)
{
	const char *id = astman_get_header(m,"ActionID");
	char idText[256];
	const char *family = astman_get_header(m, "Family");
	const char *key = astman_get_header(m, "Key");
	char tmp[MAX_DB_FIELD];
	int res;

	if (ast_strlen_zero(family)) {
		astman_send_error(s, m, "No family specified.");
		return 0;
	}
	if (ast_strlen_zero(key)) {
		astman_send_error(s, m, "No key specified.");
		return 0;
	}

	idText[0] = '\0';
	if (!ast_strlen_zero(id))
		snprintf(idText, sizeof(idText) ,"ActionID: %s\r\n", id);

	res = ast_db_get(family, key, tmp, sizeof(tmp));
	if (res) {
		astman_send_error(s, m, "Database entry not found");
	} else {
		astman_send_listack(s, m, "Result will follow", "start");

		astman_append(s, "Event: DBGetResponse\r\n"
				"Family: %s\r\n"
				"Key: %s\r\n"
				"Val: %s\r\n"
				"%s"
				"\r\n",
				family, key, tmp, idText);

		astman_send_list_complete_start(s, m, "DBGetComplete", 1);
		astman_send_list_complete_end(s);
	}
	return 0;
}

static int manager_db_tree_get(struct mansession *s, const struct message *m)
{
	char prefix[MAX_DB_FIELD];
	char idText[256];
	const char *id = astman_get_header(m,"ActionID");
	const char *family = astman_get_header(m, "Family");
	const char *key = astman_get_header(m, "Key");
	sqlite3_stmt *stmt = gettree_stmt;
	int count = 0;

	if (!ast_strlen_zero(family) && !ast_strlen_zero(key)) {
		/* Family and key tree */
		snprintf(prefix, sizeof(prefix), "/%s/%s", family, key);
	} else if (!ast_strlen_zero(family)) {
		/* Family only */
		snprintf(prefix, sizeof(prefix), "/%s", family);
	} else {
		/* Neither */
		prefix[0] = '\0';
		stmt = gettree_all_stmt;
	}

	idText[0] = '\0';
	if (!ast_strlen_zero(id)) {
		snprintf(idText, sizeof(idText) ,"ActionID: %s\r\n", id);
	}

	ast_mutex_lock(&dblock);
	if (!ast_strlen_zero(prefix) && (sqlite3_bind_text(stmt, 1, prefix, -1, SQLITE_STATIC) != SQLITE_OK)) {
		ast_log(LOG_WARNING, "Couldn't bind %s to stmt: %s\n", prefix, sqlite3_errmsg(astdb));
		sqlite3_reset(stmt);
		ast_mutex_unlock(&dblock);
		astman_send_error(s, m, "Unable to search database");
		return 0;
	}

	astman_send_listack(s, m, "Result will follow", "start");

	while (sqlite3_step(stmt) == SQLITE_ROW) {
		const char *key_s, *value_s;
		if (!(key_s = (const char *) sqlite3_column_text(stmt, 0))) {
			ast_log(LOG_WARNING, "Skipping invalid key!\n");
			continue;
		}
		if (!(value_s = (const char *) sqlite3_column_text(stmt, 1))) {
			ast_log(LOG_WARNING, "Skipping invalid value!\n");
			continue;
		}
		astman_append(s, "Event: DBGetTreeResponse\r\n"
			"Key: %s\r\n"
			"Val: %s\r\n"
			"%s"
			"\r\n",
			key_s, value_s, idText);
		count++;
	}

	sqlite3_reset(stmt);
	ast_mutex_unlock(&dblock);

	astman_send_list_complete_start(s, m, "DBGetTreeComplete", count);
	astman_send_list_complete_end(s);

	return 0;
}

static int manager_dbdel(struct mansession *s, const struct message *m)
{
	const char *family = astman_get_header(m, "Family");
	const char *key = astman_get_header(m, "Key");
	int res;

	if (ast_strlen_zero(family)) {
		astman_send_error(s, m, "No family specified.");
		return 0;
	}

	if (ast_strlen_zero(key)) {
		astman_send_error(s, m, "No key specified.");
		return 0;
	}

	res = ast_db_del2(family, key);
	if (res)
		astman_send_error(s, m, "Database entry could not be deleted");
	else
		astman_send_ack(s, m, "Key deleted successfully");

	return 0;
}

static int manager_dbdeltree(struct mansession *s, const struct message *m)
{
	const char *family = astman_get_header(m, "Family");
	const char *key = astman_get_header(m, "Key");
	int num_deleted;

	if (ast_strlen_zero(family)) {
		astman_send_error(s, m, "No family specified.");
		return 0;
	}

	if (!ast_strlen_zero(key)) {
		num_deleted = ast_db_deltree(family, key);
	} else {
		num_deleted = ast_db_deltree(family, NULL);
	}

	if (num_deleted < 0) {
		astman_send_error(s, m, "Database unavailable");
	} else if (num_deleted == 0) {
		astman_send_error(s, m, "Database entry not found");
	} else {
		astman_send_ack(s, m, "Key tree deleted successfully");
	}

	return 0;
}

/*!
 * \internal
 * \brief Signal the astdb sync thread to do its thing.
 *
 * \note dblock is assumed to be held when calling this function.
 */
static void db_sync(void)
{
	dosync = 1;
	ast_cond_signal(&dbcond);
}

/*!
 * \internal
 * \brief astdb sync thread
 *
 * This thread is in charge of syncing astdb to disk after a change.
 * By pushing it off to this thread to take care of, this I/O bound operation
 * will not block other threads from performing other critical processing.
 * If changes happen rapidly, this thread will also ensure that the sync
 * operations are rate limited.
 */
static void *db_sync_thread(void *data)
{
	ast_mutex_lock(&dblock);
	ast_db_begin_transaction();
	for (;;) {
		/* If dosync is set, db_sync() was called during sleep(1),
		 * and the pending transaction should be committed.
		 * Otherwise, block until db_sync() is called.
		 */
		while (!dosync) {
			ast_cond_wait(&dbcond, &dblock);
		}
		dosync = 0;
		if (ast_db_commit_transaction()) {
			ast_db_rollback_transaction();
		}
		if (doexit) {
			ast_mutex_unlock(&dblock);
			break;
		}
		ast_db_begin_transaction();
		ast_mutex_unlock(&dblock);
		sleep(1);
		ast_mutex_lock(&dblock);
	}

	return NULL;
}

/*!
 * \internal
 * \brief Clean up resources on Asterisk shutdown
 */
static void astdb_atexit(void)
{
	ast_cli_unregister_multiple(cli_database, ARRAY_LEN(cli_database));
	ast_manager_unregister("DBGet");
	ast_manager_unregister("DBGetTree");
	ast_manager_unregister("DBPut");
	ast_manager_unregister("DBDel");
	ast_manager_unregister("DBDelTree");

	/* Set doexit to 1 to kill thread. db_sync must be called with
	 * mutex held. */
	ast_mutex_lock(&dblock);
	doexit = 1;
	db_sync();
	ast_mutex_unlock(&dblock);

	pthread_join(syncthread, NULL);
	ast_mutex_lock(&dblock);
	clean_statements();
	if (sqlite3_close(astdb) == SQLITE_OK) {
		astdb = NULL;
	}
	ast_mutex_unlock(&dblock);
}

int astdb_init(void)
{
	ast_cond_init(&dbcond, NULL);

	if (db_init()) {
		return -1;
	}

	if (ast_pthread_create_background(&syncthread, NULL, db_sync_thread, NULL)) {
		return -1;
	}

	ast_register_atexit(astdb_atexit);
	ast_cli_register_multiple(cli_database, ARRAY_LEN(cli_database));
	ast_manager_register_xml_core("DBGet", EVENT_FLAG_SYSTEM | EVENT_FLAG_REPORTING, manager_dbget);
	ast_manager_register_xml_core("DBGetTree", EVENT_FLAG_SYSTEM | EVENT_FLAG_REPORTING, manager_db_tree_get);
	ast_manager_register_xml_core("DBPut", EVENT_FLAG_SYSTEM, manager_dbput);
	ast_manager_register_xml_core("DBDel", EVENT_FLAG_SYSTEM, manager_dbdel);
	ast_manager_register_xml_core("DBDelTree", EVENT_FLAG_SYSTEM, manager_dbdeltree);
	return 0;
}