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Make configuration parameters fall back to their default values when they

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are removed from the configuration file.

Joachim Wieland
This commit is contained in:
Peter Eisentraut
2007-04-21 20:02:41 +00:00
parent adf7788c5e
commit b7edb568bd
3 changed files with 259 additions and 38 deletions
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158
src/backend/utils/misc/guc-file.l
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@ -4,7 +4,7 @@
*
* Copyright (c) 2000-2007, PostgreSQL Global Development Group
*
* $PostgreSQL: pgsql/src/backend/utils/misc/guc-file.l,v 1.49 2007/03/13 14:32:25 petere Exp $
* $PostgreSQL: pgsql/src/backend/utils/misc/guc-file.l,v 1.50 2007/04/21 20:02:40 petere Exp $
*/
%{
@ -116,6 +116,9 @@ ProcessConfigFile(GucContext context)
{
int elevel;
struct name_value_pair *item, *head, *tail;
int i;
bool *in_conffile = NULL;
const char *var;
Assert(context == PGC_POSTMASTER || context == PGC_SIGHUP);
@ -140,19 +143,158 @@ ProcessConfigFile(GucContext context)
/* Check if all options are valid */
for (item = head; item; item = item->next)
{
char *sep = strchr(item->name, GUC_QUALIFIER_SEPARATOR);
if (sep && !is_custom_class(item->name, sep - item->name))
{
ereport(elevel,
(errcode(ERRCODE_UNDEFINED_OBJECT),
errmsg("unrecognized configuration parameter \"%s\"",
item->name)));
goto cleanup_list;
}
if (!set_config_option(item->name, item->value, context,
PGC_S_FILE, false, false))
goto cleanup_list;
}
/* If we got here all the options checked out okay, so apply them. */
/*
* Mark all variables as not showing up in the config file. The
* allocation has to take place after ParseConfigFile() since this
* function can change num_guc_variables due to custom variables.
* It would be easier to add a new field or status bit to struct
* conf_generic, but that way we would expose internal information
* that is just needed here in the following few lines. The price
* to pay for this separation are a few more loops over the set of
* configuration options, but those are expected to be rather few
* and we only have to pay the cost at SIGHUP. We initialize
* in_conffile only here because set_config_option() makes
* guc_variables grow with custom variables.
*/
in_conffile = guc_malloc(elevel, num_guc_variables * sizeof(bool));
if (!in_conffile)
goto cleanup_list;
for (i = 0; i < num_guc_variables; i++)
in_conffile[i] = false;
for (item = head; item; item = item->next)
{
set_config_option(item->name, item->value, context,
PGC_S_FILE, false, true);
/*
* After set_config_option() the variable name item->name is
* known to exist.
*/
Assert(guc_get_index(item->name) >= 0);
in_conffile[guc_get_index(item->name)] = true;
}
for (i = 0; i < num_guc_variables; i++)
{
struct config_generic *gconf = guc_variables[i];
if (!in_conffile[i] && gconf->source == PGC_S_FILE)
{
if (gconf->context < PGC_SIGHUP)
ereport(elevel,
(errcode(ERRCODE_CANT_CHANGE_RUNTIME_PARAM),
errmsg("parameter \"%s\" cannot be changed after server start; configuration file change ignored",
gconf->name)));
else
{
/* prepare */
GucStack *stack;
if (gconf->reset_source == PGC_S_FILE)
gconf->reset_source = PGC_S_DEFAULT;
for (stack = gconf->stack; stack; stack = stack->prev)
if (stack->source == PGC_S_FILE)
stack->source = PGC_S_DEFAULT;
/* apply the default */
set_config_option(gconf->name, NULL, context,
PGC_S_DEFAULT, false, true);
}
}
else if (!in_conffile[i] && gconf->reset_source == PGC_S_FILE)
{
/*------
* Change the reset_val to default_val. Here's an
* example: In the configuration file we have
*
* seq_page_cost = 3.00
*
* Now we execute in a session
*
* SET seq_page_cost TO 4.00;
*
* Then we remove this option from the configuration file
* and send SIGHUP. Now when you execute
*
* RESET seq_page_cost;
*
* it should fall back to 1.00 (the default value for
* seq_page_cost) and not to 3.00 (which is the current
* reset_val).
*/
switch (gconf->vartype)
{
case PGC_BOOL:
{
struct config_bool *conf;
conf = (struct config_bool *) gconf;
conf->reset_val = conf->boot_val;
break;
}
case PGC_INT:
{
struct config_int *conf;
conf = (struct config_int *) gconf;
conf->reset_val = conf->boot_val;
break;
}
case PGC_REAL:
{
struct config_real *conf;
conf = (struct config_real *) gconf;
conf->reset_val = conf->boot_val;
break;
}
case PGC_STRING:
{
struct config_string *conf;
conf = (struct config_string *) gconf;
/*
* We can cast away the const here because we
* won't free the address. It is protected by
* set_string_field() and string_field_used().
*/
conf->reset_val = (char *) conf->boot_val;
break;
}
}
}
}
/* If we got here all the options checked out okay, so apply them. */
for (item = head; item; item = item->next)
set_config_option(item->name, item->value, context,
PGC_S_FILE, false, true);
/*
* Reset variables to the value of environment variables
* (PGC_S_ENV_VAR overrules PGC_S_FILE). PGPORT is ignored,
* because it cannot be changed without restart.
*/
var = getenv("PGDATESTYLE");
if (var != NULL)
set_config_option("datestyle", var, context,
PGC_S_ENV_VAR, false, true);
var = getenv("PGCLIENTENCODING");
if (var != NULL)
set_config_option("client_encoding", var, context,
PGC_S_ENV_VAR, false, true);
cleanup_list:
free(in_conffile);
free_name_value_list(head);
}
@ -312,14 +454,14 @@ ParseConfigFile(const char *config_file, const char *calling_file,
{
pfree(opt_name);
pfree(opt_value);
/* we assume error message was logged already */
/* We assume the error message was logged already. */
OK = false;
goto cleanup_exit;
}
pfree(opt_name);
pfree(opt_value);
}
else
if (pg_strcasecmp(opt_name, "include") != 0)
{
/* append to list */
struct name_value_pair *item;