db.c

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/*
 * 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"

ASTERISK_FILE_VERSION(__FILE__, "$Revision: 410606 $")

#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="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))")

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(&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_statment here as the astdb table needs to exist
    * brefore these statments 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(&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;

   ast_asprintf(&cmd, "%s/astdb2sqlite3 '%s'\n", ast_config_AST_SBIN_DIR, ast_config_AST_DB);
   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;

   sqlite3_exec(astdb, sql, callback, arg, &errmsg);
   if (errmsg) {
      ast_log(LOG_WARNING, "Error executing SQL: %s\n", 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 statment: %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_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, "Could 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;
}

struct ast_db_entry *ast_db_gettree(const char *family, const char *keytree)
{
   char prefix[MAX_DB_FIELD];
   sqlite3_stmt *stmt = gettree_stmt;
   struct ast_db_entry *cur, *last = NULL, *ret = NULL;

   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 = gettree_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, "Could 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))) {
         break;
      }
      if (!(value_s = (const char *) sqlite3_column_text(stmt, 1))) {
         break;
      }
      if (!(cur = ast_malloc(sizeof(*cur) + strlen(key_s) + strlen(value_s) + 2))) {
         break;
      }
      cur->next = NULL;
      cur->key = cur->data + strlen(value_s) + 1;
      strcpy(cur->data, value_s);
      strcpy(cur->key, key_s);
      if (last) {
         last->next = cur;
      } else {
         ret = cur;
      }
      last = cur;
   }
   sqlite3_reset(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_del(a->argv[2], a->argv[3]);
   if (res) {
      ast_cli(a->fd, "Database entry does not exist.\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, "Could 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, "Could 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;
   }

   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_ack(s, m, "Result will follow");
      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_append(s, "Event: DBGetComplete\r\n"
            "%s"
            "\r\n",
            idText);
   }
   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_del(family, key);
   if (res)
      astman_send_error(s, m, "Database entry not found");
   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("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)
{
   if (db_init()) {
      return -1;
   }

   ast_cond_init(&dbcond, NULL);
   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("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;
}