Skip to content

P
Postgres FD Implementation
Commit b7edb568 authored by Peter Eisentraut's avatar Peter Eisentraut
Browse files
Options

Make configuration parameters fall back to their default values when they 

are removed from the configuration file.

Joachim Wieland
parent adf7788c
Hide whitespace changes
Inline Side-by-side
Showing with 258 additions and 37 deletions
src/backend/utils/misc/guc-file.l
View file @ b7edb568
......@@ -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)
{
/*
* 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;
......
src/backend/utils/misc/guc.c
View file @ b7edb568
......@@ -10,7 +10,7 @@
* Written by Peter Eisentraut <peter_e@gmx.net>.
*
* IDENTIFICATION
* $PostgreSQL: pgsql/src/backend/utils/misc/guc.c,v 1.386 2007/04/18 16:44:18 alvherre Exp $
* $PostgreSQL: pgsql/src/backend/utils/misc/guc.c,v 1.387 2007/04/21 20:02:40 petere Exp $
*
*--------------------------------------------------------------------
*/
......@@ -2481,7 +2481,8 @@ set_string_field(struct config_string * conf, char **field, char *newval)
if (oldval == NULL ||
oldval == *(conf->variable) ||
oldval == conf->reset_val ||
oldval == conf->tentative_val)
oldval == conf->tentative_val ||
oldval == conf->boot_val)
return;
for (stack = conf->gen.stack; stack; stack = stack->prev)
{
......@@ -2504,7 +2505,8 @@ string_field_used(struct config_string * conf, char *strval)
if (strval == *(conf->variable) ||
strval == conf->reset_val ||
strval == conf->tentative_val)
strval == conf->tentative_val ||
strval == conf->boot_val)
return true;
for (stack = conf->gen.stack; stack; stack = stack->prev)
{
......@@ -2673,6 +2675,18 @@ add_guc_variable(struct config_generic * var, int elevel)
return true;
}
static int
guc_get_index(const char *name)
{
int i;
for (i = 0; i < num_guc_variables; i++)
if (strcasecmp(name, guc_variables[i]->name) == 0)
return i;
return -1;
}
/*
* Create and add a placeholder variable. It's presumed to belong
* to a valid custom variable class at this point.
......@@ -2851,39 +2865,39 @@ InitializeGUCOptions(void)
struct config_bool *conf = (struct config_bool *) gconf;
if (conf->assign_hook)
if (!(*conf->assign_hook) (conf->reset_val, true,
if (!(*conf->assign_hook) (conf->boot_val, true,
PGC_S_DEFAULT))
elog(FATAL, "failed to initialize %s to %d",
conf->gen.name, (int) conf->reset_val);
*conf->variable = conf->reset_val;
conf->gen.name, (int) conf->boot_val);
*conf->variable = conf->reset_val = conf->boot_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);
Assert(conf->boot_val >= conf->min);
Assert(conf->boot_val <= conf->max);
if (conf->assign_hook)
if (!(*conf->assign_hook) (conf->reset_val, true,
if (!(*conf->assign_hook) (conf->boot_val, true,
PGC_S_DEFAULT))
elog(FATAL, "failed to initialize %s to %d",
conf->gen.name, conf->reset_val);
*conf->variable = conf->reset_val;
conf->gen.name, conf->boot_val);
*conf->variable = conf->reset_val = conf->boot_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->boot_val >= conf->min);
Assert(conf->boot_val <= conf->max);
if (conf->assign_hook)
if (!(*conf->assign_hook) (conf->reset_val, true,
if (!(*conf->assign_hook) (conf->boot_val, true,
PGC_S_DEFAULT))
elog(FATAL, "failed to initialize %s to %g",
conf->gen.name, conf->reset_val);
*conf->variable = conf->reset_val;
conf->gen.name, conf->boot_val);
*conf->variable = conf->reset_val = conf->boot_val;
break;
}
case PGC_STRING:
......@@ -3945,6 +3959,13 @@ set_config_option(const char *name, const char *value,
return false;
}
/*
* Do not replace a value that has been set on the command line by a SIGHUP
* reload
*/
if (context == PGC_SIGHUP && record->source == PGC_S_ARGV)
return true;
/*
* Check if the option can be set at this time. See guc.h for the precise
* rules. Note that we don't want to throw errors if we're in the SIGHUP
......@@ -4040,19 +4061,26 @@ set_config_option(const char *name, const char *value,
}
/*
* Should we set reset/stacked values? (If so, the behavior is not
* transactional.)
* Should we set reset/stacked values? (If so, the behavior is not
* transactional.) This is done either when we get a default
* value from the database's/user's/client's default settings or
* when we reset a value to its default.
*/
makeDefault = changeVal && (source <= PGC_S_OVERRIDE) && (value != NULL);
makeDefault = changeVal && (source <= PGC_S_OVERRIDE)
&& ((value != NULL) || source == PGC_S_DEFAULT);
/*
* Ignore attempted set if overridden by previously processed setting.
* However, if changeVal is false then plow ahead anyway since we are
* trying to find out if the value is potentially good, not actually use
* it. Also keep going if makeDefault is true, since we may want to set
* the reset/stacked values even if we can't set the variable itself.
* Ignore attempted set if overridden by previously processed
* setting. However, if changeVal is false then plow ahead anyway
* since we are trying to find out if the value is potentially
* good, not actually use it. Also keep going if makeDefault is
* true, since we may want to set the reset/stacked values even if
* we can't set the variable itself. There's one exception to
* this rule: if we want to apply the default value to variables
* that were removed from the configuration file. This is
* indicated by source == PGC_S_DEFAULT.
*/
if (record->source > source)
if (record->source > source && source != PGC_S_DEFAULT)
{
if (changeVal && !makeDefault)
{
......@@ -4084,6 +4112,14 @@ set_config_option(const char *name, const char *value,
return false;
}
}
/*
* If value == NULL and source == PGC_S_DEFAULT then
* we reset some value to its default (removed from
* configuration file).
*/
else if (source == PGC_S_DEFAULT)
newval = conf->boot_val;
/* else we handle a "RESET varname" command */
else
{
newval = conf->reset_val;
......@@ -4168,6 +4204,14 @@ set_config_option(const char *name, const char *value,
return false;
}
}
/*
* If value == NULL and source == PGC_S_DEFAULT then
* we reset some value to its default (removed from
* configuration file).
*/
else if (source == PGC_S_DEFAULT)
newval = conf->boot_val;
/* else we handle a "RESET varname" command */
else
{
newval = conf->reset_val;
......@@ -4252,6 +4296,14 @@ set_config_option(const char *name, const char *value,
return false;
}
}
/*
* If value == NULL and source == PGC_S_DEFAULT then
* we reset some value to its default (removed from
* configuration file).
*/
else if (source == PGC_S_DEFAULT)
newval = conf->boot_val;
/* else we handle a "RESET varname" command */
else
{
newval = conf->reset_val;
......@@ -4330,6 +4382,23 @@ set_config_option(const char *name, const char *value,
if (conf->gen.flags & GUC_IS_NAME)
truncate_identifier(newval, strlen(newval), true);
}
/*
* If value == NULL and source == PGC_S_DEFAULT then
* we reset some value to its default (removed from
* configuration file).
*/
else if (source == PGC_S_DEFAULT)
{
if (conf->boot_val == NULL)
newval = NULL;
else
{
newval = guc_strdup(elevel, conf->boot_val);
if (newval == NULL)
return false;
}
}
/* else we handle a "RESET varname" command */
else if (conf->reset_val)
{
/*
......@@ -6404,6 +6473,13 @@ assign_custom_variable_classes(const char *newval, bool doit, GucSource source)
int c;
StringInfoData buf;
/*
* Resetting custom_variable_classes by removing it from the
* configuration file will lead to newval = NULL
*/
if (newval == NULL)
return guc_strdup(ERROR, "");
initStringInfo(&buf);
while ((c = *cp++) != 0)
{
......@@ -6448,7 +6524,7 @@ assign_custom_variable_classes(const char *newval, bool doit, GucSource source)
if (buf.len == 0)
newval = NULL;
else if (doit)
newval = strdup(buf.data);
newval = guc_strdup(ERROR, buf.data);
pfree(buf.data);
return newval;
......
src/include/utils/guc_tables.h
View file @ b7edb568
......@@ -7,7 +7,7 @@
*
* Portions Copyright (c) 1996-2007, PostgreSQL Global Development Group
*
* $PostgreSQL: pgsql/src/include/utils/guc_tables.h,v 1.32 2007/03/13 14:32:25 petere Exp $
* $PostgreSQL: pgsql/src/include/utils/guc_tables.h,v 1.33 2007/04/21 20:02:41 petere Exp $
*
*-------------------------------------------------------------------------
*/
......@@ -154,10 +154,11 @@ struct config_bool
/* these fields must be set correctly in initial value: */
/* (all but reset_val are constants) */
bool *variable;
bool reset_val;
bool boot_val;
GucBoolAssignHook assign_hook;
GucShowHook show_hook;
/* variable fields, initialized at runtime: */
bool reset_val;
bool tentative_val;
};
......@@ -167,12 +168,13 @@ struct config_int
/* these fields must be set correctly in initial value: */
/* (all but reset_val are constants) */
int *variable;
int reset_val;
int boot_val;
int min;
int max;
GucIntAssignHook assign_hook;
GucShowHook show_hook;
/* variable fields, initialized at runtime: */
int reset_val;
int tentative_val;
};
......@@ -182,12 +184,13 @@ struct config_real
/* these fields must be set correctly in initial value: */
/* (all but reset_val are constants) */
double *variable;
double reset_val;
double boot_val;
double min;
double max;
GucRealAssignHook assign_hook;
GucShowHook show_hook;
/* variable fields, initialized at runtime: */
double reset_val;
double tentative_val;
};
......
Markdown is supported
0% or
You are about to add 0 people to the discussion. Proceed with caution.
Finish editing this message first!
Please register or to comment