guc.c

来自「PostgreSQL7.4.6 for Linux」· C语言 代码 · 共 2,468 行 · 第 1/5 页

	{
		/* Can't be set in postgresql.conf */
		{"server_version", PGC_INTERNAL, UNGROUPED,
			gettext_noop("Shows the server version."),
			NULL,
			GUC_REPORT | GUC_NOT_IN_SAMPLE | GUC_DISALLOW_IN_FILE
		},
		&server_version_string,
		PG_VERSION, NULL, NULL
	},

	{
		/* Not for general use --- used by SET SESSION AUTHORIZATION */
		{"session_authorization", PGC_USERSET, UNGROUPED,
			gettext_noop("Shows the session user name."),
			NULL,
			GUC_REPORT | GUC_NO_SHOW_ALL | GUC_NO_RESET_ALL | GUC_NOT_IN_SAMPLE | GUC_DISALLOW_IN_FILE
		},
		&session_authorization_string,
		NULL, assign_session_authorization, show_session_authorization
	},

#ifdef HAVE_SYSLOG
	{
		{"syslog_facility", PGC_POSTMASTER, LOGGING_SYSLOG,
			gettext_noop("Sets the syslog \"facility\" to be used when syslog enabled."),
			gettext_noop("Valid values are LOCAL0, LOCAL1, LOCAL2, LOCAL3, "
						 "LOCAL4, LOCAL5, LOCAL6, LOCAL7.")
		},
		&Syslog_facility,
		"LOCAL0", assign_facility, NULL
	},
	{
		{"syslog_ident", PGC_POSTMASTER, LOGGING_SYSLOG,
			gettext_noop("Sets the program name used to identify PostgreSQL messages "
						 "in syslog."),
			NULL
		},
		&Syslog_ident,
		"postgres", NULL, NULL
	},
#endif

	{
		{"TimeZone", PGC_USERSET, CLIENT_CONN_LOCALE,
			gettext_noop("Sets the time zone for displaying and interpreting time stamps."),
			NULL
		},
		&timezone_string,
		"UNKNOWN", assign_timezone, show_timezone
	},

	{
		{"transaction_isolation", PGC_USERSET, CLIENT_CONN_STATEMENT,
			gettext_noop("Shows the current transaction's isolation level."),
			NULL,
			GUC_NO_RESET_ALL | GUC_NOT_IN_SAMPLE | GUC_DISALLOW_IN_FILE
		},
		&XactIsoLevel_string,
		NULL, assign_XactIsoLevel, show_XactIsoLevel
	},

	{
		{"unix_socket_group", PGC_POSTMASTER, CONN_AUTH_SETTINGS,
			gettext_noop("Sets the owning group of the Unix-domain socket."),
			gettext_noop("(The owning user of the socket is always the user "
						 "that starts the server.)")
		},
		&Unix_socket_group,
		"", NULL, NULL
	},

	{
		{"unix_socket_directory", PGC_POSTMASTER, CONN_AUTH_SETTINGS,
			gettext_noop("Sets the directory where the Unix-domain socket will be created."),
			NULL
		},
		&UnixSocketDir,
		"", NULL, NULL
	},

	{
		{"virtual_host", PGC_POSTMASTER, CONN_AUTH_SETTINGS,
			gettext_noop("Sets the host name or IP address to listen to."),
			NULL
		},
		&VirtualHost,
		"", NULL, NULL
	},

	{
		{"wal_sync_method", PGC_SIGHUP, WAL_SETTINGS,
			gettext_noop("Selects the method used for forcing WAL updates out to disk."),
			NULL
		},
		&XLOG_sync_method,
		XLOG_sync_method_default, assign_xlog_sync_method, NULL
	},

	/* End-of-list marker */
	{
		{NULL, 0, 0, NULL, NULL}, NULL, NULL, NULL, NULL
	}
};

/******** end of options list ********/


/*
 * Actual lookup of variables is done through this single, sorted array.
 */
struct config_generic **guc_variables;
int			num_guc_variables;

static bool guc_dirty;			/* TRUE if need to do commit/abort work */

static bool reporting_enabled;	/* TRUE to enable GUC_REPORT */

static char *guc_string_workspace;		/* for avoiding memory leaks */


static int	guc_var_compare(const void *a, const void *b);
static void ReportGUCOption(struct config_generic * record);
static char *_ShowOption(struct config_generic * record);


/*
 * Build the sorted array.	This is split out so that it could be
 * re-executed after startup (eg, we could allow loadable modules to
 * add vars, and then we'd need to re-sort).
 */
void
build_guc_variables(void)
{
	int			num_vars = 0;
	struct config_generic **guc_vars;
	int			i;

	for (i = 0; ConfigureNamesBool[i].gen.name; i++)
	{
		struct config_bool *conf = &ConfigureNamesBool[i];

		/* Rather than requiring vartype to be filled in by hand, do this: */
		conf->gen.vartype = PGC_BOOL;
		num_vars++;
	}

	for (i = 0; ConfigureNamesInt[i].gen.name; i++)
	{
		struct config_int *conf = &ConfigureNamesInt[i];

		conf->gen.vartype = PGC_INT;
		num_vars++;
	}

	for (i = 0; ConfigureNamesReal[i].gen.name; i++)
	{
		struct config_real *conf = &ConfigureNamesReal[i];

		conf->gen.vartype = PGC_REAL;
		num_vars++;
	}

	for (i = 0; ConfigureNamesString[i].gen.name; i++)
	{
		struct config_string *conf = &ConfigureNamesString[i];

		conf->gen.vartype = PGC_STRING;
		num_vars++;
	}

	guc_vars = (struct config_generic **)
		malloc(num_vars * sizeof(struct config_generic *));
	if (!guc_vars)
		ereport(FATAL,
				(errcode(ERRCODE_OUT_OF_MEMORY),
				 errmsg("out of memory")));

	num_vars = 0;

	for (i = 0; ConfigureNamesBool[i].gen.name; i++)
		guc_vars[num_vars++] = &ConfigureNamesBool[i].gen;

	for (i = 0; ConfigureNamesInt[i].gen.name; i++)
		guc_vars[num_vars++] = &ConfigureNamesInt[i].gen;

	for (i = 0; ConfigureNamesReal[i].gen.name; i++)
		guc_vars[num_vars++] = &ConfigureNamesReal[i].gen;

	for (i = 0; ConfigureNamesString[i].gen.name; i++)
		guc_vars[num_vars++] = &ConfigureNamesString[i].gen;

	qsort((void *) guc_vars, num_vars, sizeof(struct config_generic *),
		  guc_var_compare);

	if (guc_variables)
		free(guc_variables);
	guc_variables = guc_vars;
	num_guc_variables = num_vars;
}


/*
 * Look up option NAME. If it exists, return a pointer to its record,
 * else return NULL.
 */
static struct config_generic *
find_option(const char *name)
{
	const char **key = &name;
	struct config_generic **res;

	Assert(name);

	/*
	 * by equating const char ** with struct config_generic *, we are
	 * assuming the name field is first in config_generic.
	 */
	res = (struct config_generic **) bsearch((void *) &key,
											 (void *) guc_variables,
											 num_guc_variables,
										 sizeof(struct config_generic *),
											 guc_var_compare);
	if (res)
		return *res;
	return NULL;
}


/*
 * comparator for qsorting and bsearching guc_variables array
 */
static int
guc_var_compare(const void *a, const void *b)
{
	struct config_generic *confa = *(struct config_generic **) a;
	struct config_generic *confb = *(struct config_generic **) b;
	const char *namea;
	const char *nameb;

	/*
	 * The temptation to use strcasecmp() here must be resisted, because
	 * the array ordering has to remain stable across setlocale() calls.
	 * So, build our own with a simple ASCII-only downcasing.
	 */
	namea = confa->name;
	nameb = confb->name;
	while (*namea && *nameb)
	{
		char		cha = *namea++;
		char		chb = *nameb++;

		if (cha >= 'A' && cha <= 'Z')
			cha += 'a' - 'A';
		if (chb >= 'A' && chb <= 'Z')
			chb += 'a' - 'A';
		if (cha != chb)
			return cha - chb;
	}
	if (*namea)
		return 1;				/* a is longer */
	if (*nameb)
		return -1;				/* b is longer */
	return 0;
}


/*
 * Initialize GUC options during program startup.
 */
void
InitializeGUCOptions(void)
{
	int			i;
	char	   *env;

	/*
	 * Build sorted array of all GUC variables.
	 */
	build_guc_variables();

	/*
	 * Load all variables with their compiled-in defaults, and initialize
	 * status fields as needed.
	 */
	for (i = 0; i < num_guc_variables; i++)
	{
		struct config_generic *gconf = guc_variables[i];

		gconf->status = 0;
		gconf->reset_source = PGC_S_DEFAULT;
		gconf->session_source = PGC_S_DEFAULT;
		gconf->tentative_source = PGC_S_DEFAULT;
		gconf->source = PGC_S_DEFAULT;

		switch (gconf->vartype)
		{
			case PGC_BOOL:
				{
					struct config_bool *conf = (struct config_bool *) gconf;

					if (conf->assign_hook)
						if (!(*conf->assign_hook) (conf->reset_val, true, false))
							elog(FATAL, "failed to initialize %s to %d",
								 conf->gen.name, (int) conf->reset_val);
					*conf->variable = conf->reset_val;
					conf->session_val = conf->reset_val;
					break;
				}
			case PGC_INT:
				{
					struct config_int *conf = (struct config_int *) gconf;

					Assert(conf->reset_val >= conf->min);
					Assert(conf->reset_val <= conf->max);

					/*
					 * Check to make sure we only have valid
					 * PGC_USERLIMITs
					 */
					Assert(conf->gen.context != PGC_USERLIMIT ||
						   strcmp(conf->gen.name, "log_min_duration_statement") == 0);
					if (conf->assign_hook)
						if (!(*conf->assign_hook) (conf->reset_val, true, false))
							elog(FATAL, "failed to initialize %s to %d",
								 conf->gen.name, conf->reset_val);
					*conf->variable = conf->reset_val;
					conf->session_val = conf->reset_val;
					break;
				}
			case PGC_REAL:
				{
					struct config_real *conf = (struct config_real *) gconf;

					Assert(conf->reset_val >= conf->min);
					Assert(conf->reset_val <= conf->max);
					Assert(conf->gen.context != PGC_USERLIMIT);
					if (conf->assign_hook)
						if (!(*conf->assign_hook) (conf->reset_val, true, false))
							elog(FATAL, "failed to initialize %s to %g",
								 conf->gen.name, conf->reset_val);
					*conf->variable = conf->reset_val;
					conf->session_val = conf->reset_val;
					break;
				}
			case PGC_STRING:
				{
					struct config_string *conf = (struct config_string *) gconf;
					char	   *str;

					/*
					 * Check to make sure we only have valid
					 * PGC_USERLIMITs
					 */
					Assert(conf->gen.context != PGC_USERLIMIT ||
						   conf->assign_hook == assign_log_min_messages ||
					   conf->assign_hook == assign_client_min_messages ||
						conf->assign_hook == assign_min_error_statement);
					*conf->variable = NULL;
					conf->reset_val = NULL;
					conf->session_val = NULL;
					conf->tentative_val = NULL;

					if (conf->boot_val == NULL)
					{
						/* Cannot set value yet */
						break;
					}

					str = strdup(conf->boot_val);
					if (str == NULL)
						ereport(FATAL,
								(errcode(ERRCODE_OUT_OF_MEMORY),
								 errmsg("out of memory")));
					conf->reset_val = str;

					if (conf->assign_hook)
					{
						const char *newstr;

						newstr = (*conf->assign_hook) (str, true, false);
						if (newstr == NULL)
						{
							elog(FATAL, "failed to initialize %s to \"%s\"",
								 conf->gen.name, str);
						}
						else if (newstr != str)
						{
							free(str);

							/*
							 * See notes in set_config_option about
							 * casting
							 */
							str = (char *) newstr;
							conf->reset_val = str;
						}
					}
					*conf->variable = str;
					conf->session_val = str;
					break;
				}
		}
	}

	guc_dirty = false;

	reporting_enabled = false;

	guc_string_workspace = NULL;

	/*
	 * Prevent any attempt to override the transaction modes from
	 * non-interactive sources.
	 */
	SetConfigOption("transaction_isolation", "default",
					PGC_POSTMASTER, PGC_S_OVERRIDE);
	SetConfigOption("transaction_read_only", "no",
					PGC_POSTMASTER, PGC_S_OVERRIDE);

	/*
	 * For historical reasons, some GUC parameters can receive defaults
	 * from environment variables.	Process those settings.
	 */

	env = getenv("PGPORT");
	if (env != NULL)
		SetConfigOption("port", env, PGC_POSTMASTER, PGC_S_ENV_VAR);

	env = getenv("PGDATESTYLE");
	if (env != NULL)
		SetConfigOption("datestyle", env, PGC_POSTMASTER, PGC_S_ENV_VAR);

	env = getenv("TZ");
	if (env != NULL)
		SetConfigOption("timezone", env, PGC_POSTMASTER, PGC_S_ENV_VAR);

	env = getenv("PGCLIENTENCODING");
	if (env != NULL)
		SetConfigOption("client_encoding", env, PGC_POSTMASTER, PGC_S_ENV_VAR);
}


/*
 * Reset all options to their saved default values (implements RESET ALL)
 */
void
ResetAllOptions(void)
{
	int			i;

	for (i = 0; i < num_guc_variables; i++)
	{
		struct config_generic *gconf = guc_variables[i];

		/* Don't reset non-SET-able values */
		if (gconf->context != PGC_SUSET &&
			gconf->context != PGC_USERLIMIT &&
			gconf->context != PGC_USERSET)
			continue;
		/* Don't reset if special exclusion from RESET ALL */
		if (gconf->flags & GUC_NO_RESET_ALL)
			continue;
		/* No need to reset if wasn't SET */
		if (gconf->source <= PGC_S_OVERRIDE)
			continue;

		switch (gconf->vartype)
		{
			case PGC_BOOL:
				{
					struct config_bool *conf = (struct config_bool *) gconf;

					if (conf->assign_hook)
						if (!(*conf->assign_hook) (conf->reset_val, true, true))
							elog(ERROR, "failed to reset %s", conf->gen.name);
					*conf->variable = conf->reset_val;
					conf->tentative_val = conf->reset_val;
					conf->gen.source = conf->gen.reset_source;
					conf->gen.tentative_source = conf->gen.reset_source;
					conf->gen.status |= GUC_HAVE_TENTATIVE;
					guc_dirty = true;
					break;
				}
			case PGC_INT:
				{
					struct config_int *conf = (struct config_int *) gconf;

					if (conf->assign_hook)
						if (!(*conf->assign_hook) (conf->reset_val, true, true))
							elog(ERROR, "failed to reset %s", conf->gen.name);
					*conf->variable = conf->reset_val;
					conf->tentative_val = conf->reset_val;