in ext/pg_query/src_backend_utils_misc_guc.c [672:1346]
static void reapply_stacked_values(struct config_generic *variable,
struct config_string *pHolder,
GucStack *stack,
const char *curvalue,
GucContext curscontext, GucSource cursource);
static void ShowGUCConfigOption(const char *name, DestReceiver *dest);
static void ShowAllGUCConfig(DestReceiver *dest);
static char *_ShowOption(struct config_generic *record, bool use_units);
static bool validate_option_array_item(const char *name, const char *value,
bool skipIfNoPermissions);
static void write_auto_conf_file(int fd, const char *filename, ConfigVariable *head_p);
static void replace_auto_config_value(ConfigVariable **head_p, ConfigVariable **tail_p,
const char *name, const char *value);
/*
* Some infrastructure for checking malloc/strdup/realloc calls
*/
/*
* Detect whether strval is referenced anywhere in a GUC string item
*/
/*
* Support for assigning to a field of a string GUC item. Free the prior
* value if it's not referenced anywhere else in the item (including stacked
* states).
*/
/*
* Detect whether an "extra" struct is referenced anywhere in a GUC item
*/
/*
* Support for assigning to an "extra" field of a GUC item. Free the prior
* value if it's not referenced anywhere else in the item (including stacked
* states).
*/
/*
* Support for copying a variable's active value into a stack entry.
* The "extra" field associated with the active value is copied, too.
*
* NB: be sure stringval and extra fields of a new stack entry are
* initialized to NULL before this is used, else we'll try to free() them.
*/
/*
* Support for discarding a no-longer-needed value in a stack entry.
* The "extra" field associated with the stack entry is cleared, too.
*/
/*
* Fetch the sorted array pointer (exported for help_config.c's use ONLY)
*/
/*
* Build the sorted array. This is split out so that it could be
* re-executed after startup (e.g., we could allow loadable modules to
* add vars, and then we'd need to re-sort).
*/
/*
* Add a new GUC variable to the list of known variables. The
* list is expanded if needed.
*/
/*
* Create and add a placeholder variable for a custom variable name.
*/
/*
* Look up option NAME. If it exists, return a pointer to its record,
* else return NULL. If create_placeholders is true, we'll create a
* placeholder record for a valid-looking custom variable name.
*/
/*
* comparator for qsorting and bsearching guc_variables array
*/
/*
* the bare comparison function for GUC names
*/
/*
* Initialize GUC options during program startup.
*
* Note that we cannot read the config file yet, since we have not yet
* processed command-line switches.
*/
/*
* Assign any GUC values that can come from the server's environment.
*
* This is called from InitializeGUCOptions, and also from ProcessConfigFile
* to deal with the possibility that a setting has been removed from
* postgresql.conf and should now get a value from the environment.
* (The latter is a kludge that should probably go away someday; if so,
* fold this back into InitializeGUCOptions.)
*/
/*
* Initialize one GUC option variable to its compiled-in default.
*
* Note: the reason for calling check_hooks is not that we think the boot_val
* might fail, but that the hooks might wish to compute an "extra" struct.
*/
/*
* Select the configuration files and data directory to be used, and
* do the initial read of postgresql.conf.
*
* This is called after processing command-line switches.
* userDoption is the -D switch value if any (NULL if unspecified).
* progname is just for use in error messages.
*
* Returns true on success; on failure, prints a suitable error message
* to stderr and returns false.
*/
/*
* Reset all options to their saved default values (implements RESET ALL)
*/
/*
* push_old_value
* Push previous state during transactional assignment to a GUC variable.
*/
/*
* Do GUC processing at main transaction start.
*/
/*
* Enter a new nesting level for GUC values. This is called at subtransaction
* start, and when entering a function that has proconfig settings, and in
* some other places where we want to set GUC variables transiently.
* NOTE we must not risk error here, else subtransaction start will be unhappy.
*/
/*
* Do GUC processing at transaction or subtransaction commit or abort, or
* when exiting a function that has proconfig settings, or when undoing a
* transient assignment to some GUC variables. (The name is thus a bit of
* a misnomer; perhaps it should be ExitGUCNestLevel or some such.)
* During abort, we discard all GUC settings that were applied at nesting
* levels >= nestLevel. nestLevel == 1 corresponds to the main transaction.
*/
/*
* Start up automatic reporting of changes to variables marked GUC_REPORT.
* This is executed at completion of backend startup.
*/
/*
* ReportGUCOption: if appropriate, transmit option value to frontend
*/
/*
* Convert a value from one of the human-friendly units ("kB", "min" etc.)
* to the given base unit. 'value' and 'unit' are the input value and unit
* to convert from (there can be trailing spaces in the unit string).
* The converted value is stored in *base_value.
* It's caller's responsibility to round off the converted value as necessary
* and check for out-of-range.
*
* Returns true on success, false if the input unit is not recognized.
*/
/*
* Convert an integer value in some base unit to a human-friendly unit.
*
* The output unit is chosen so that it's the greatest unit that can represent
* the value without loss. For example, if the base unit is GUC_UNIT_KB, 1024
* is converted to 1 MB, but 1025 is represented as 1025 kB.
*/
/*
* Convert a floating-point value in some base unit to a human-friendly unit.
*
* Same as above, except we have to do the math a bit differently, and
* there's a possibility that we don't find any exact divisor.
*/
/*
* Return the name of a GUC's base unit (e.g. "ms") given its flags.
* Return NULL if the GUC is unitless.
*/
/*
* Try to parse value as an integer. The accepted formats are the
* usual decimal, octal, or hexadecimal formats, as well as floating-point
* formats (which will be rounded to integer after any units conversion).
* Optionally, the value can be followed by a unit name if "flags" indicates
* a unit is allowed.
*
* If the string parses okay, return true, else false.
* If okay and result is not NULL, return the value in *result.
* If not okay and hintmsg is not NULL, *hintmsg is set to a suitable
* HINT message, or NULL if no hint provided.
*/
/*
* Try to parse value as a floating point number in the usual format.
* Optionally, the value can be followed by a unit name if "flags" indicates
* a unit is allowed.
*
* If the string parses okay, return true, else false.
* If okay and result is not NULL, return the value in *result.
* If not okay and hintmsg is not NULL, *hintmsg is set to a suitable
* HINT message, or NULL if no hint provided.
*/
/*
* Lookup the name for an enum option with the selected value.
* Should only ever be called with known-valid values, so throws
* an elog(ERROR) if the enum option is not found.
*
* The returned string is a pointer to static data and not
* allocated for modification.
*/
/*
* Lookup the value for an enum option with the selected name
* (case-insensitive).
* If the enum option is found, sets the retval value and returns
* true. If it's not found, return false and retval is set to 0.
*/
/*
* Return a list of all available options for an enum, excluding
* hidden ones, separated by the given separator.
* If prefix is non-NULL, it is added before the first enum value.
* If suffix is non-NULL, it is added to the end of the string.
*/
/*
* Parse and validate a proposed value for the specified configuration
* parameter.
*
* This does built-in checks (such as range limits for an integer parameter)
* and also calls any check hook the parameter may have.
*
* record: GUC variable's info record
* name: variable name (should match the record of course)
* value: proposed value, as a string
* source: identifies source of value (check hooks may need this)
* elevel: level to log any error reports at
* newval: on success, converted parameter value is returned here
* newextra: on success, receives any "extra" data returned by check hook
* (caller must initialize *newextra to NULL)
*
* Returns true if OK, false if not (or throws error, if elevel >= ERROR)
*/
/*
* Sets option `name' to given value.
*
* The value should be a string, which will be parsed and converted to
* the appropriate data type. The context and source parameters indicate
* in which context this function is being called, so that it can apply the
* access restrictions properly.
*
* If value is NULL, set the option to its default value (normally the
* reset_val, but if source == PGC_S_DEFAULT we instead use the boot_val).
*
* action indicates whether to set the value globally in the session, locally
* to the current top transaction, or just for the duration of a function call.
*
* If changeVal is false then don't really set the option but do all
* the checks to see if it would work.
*
* elevel should normally be passed as zero, allowing this function to make
* its standard choice of ereport level. However some callers need to be
* able to override that choice; they should pass the ereport level to use.
*
* Return value:
* +1: the value is valid and was successfully applied.
* 0: the name or value is invalid (but see below).
* -1: the value was not applied because of context, priority, or changeVal.
*
* If there is an error (non-existing option, invalid value) then an
* ereport(ERROR) is thrown *unless* this is called for a source for which
* we don't want an ERROR (currently, those are defaults, the config file,
* and per-database or per-user settings, as well as callers who specify
* a less-than-ERROR elevel). In those cases we write a suitable error
* message via ereport() and return 0.
*
* See also SetConfigOption for an external interface.
*/
#define newval (newval_union.boolval)
#undef newval
#define newval (newval_union.intval)
#undef newval
#define newval (newval_union.realval)
#undef newval
#define newval (newval_union.stringval)
#undef newval
#define newval (newval_union.enumval)
#undef newval
/*
* Set the fields for source file and line number the setting came from.
*/
/*
* Set a config option to the given value.
*
* See also set_config_option; this is just the wrapper to be called from
* outside GUC. (This function should be used when possible, because its API
* is more stable than set_config_option's.)
*
* Note: there is no support here for setting source file/line, as it
* is currently not needed.
*/
/*
* Fetch the current value of the option `name', as a string.
*
* If the option doesn't exist, return NULL if missing_ok is true (NOTE that
* this cannot be distinguished from a string variable with a NULL value!),
* otherwise throw an ereport and don't return.
*
* If restrict_privileged is true, we also enforce that only superusers and
* members of the pg_read_all_settings role can see GUC_SUPERUSER_ONLY
* variables. This should only be passed as true in user-driven calls.
*
* The string is *not* allocated for modification and is really only
* valid until the next call to configuration related functions.
*/
/*
* Get the RESET value associated with the given option.
*
* Note: this is not re-entrant, due to use of static result buffer;
* not to mention that a string variable could have its reset_val changed.
* Beware of assuming the result value is good for very long.
*/
/*
* Get the GUC flags associated with the given option.
*
* If the option doesn't exist, return 0 if missing_ok is true,
* otherwise throw an ereport and don't return.
*/
/*
* flatten_set_variable_args
* Given a parsenode List as emitted by the grammar for SET,
* convert to the flat string representation used by GUC.
*
* We need to be told the name of the variable the args are for, because
* the flattening rules vary (ugh).
*
* The result is NULL if args is NIL (i.e., SET ... TO DEFAULT), otherwise
* a palloc'd string.
*/
/*
* Write updated configuration parameter values into a temporary file.
* This function traverses the list of parameters and quotes the string
* values before writing them.
*/
/*
* Update the given list of configuration parameters, adding, replacing
* or deleting the entry for item "name" (delete if "value" == NULL).
*/
/*
* Execute ALTER SYSTEM statement.
*
* Read the old PG_AUTOCONF_FILENAME file, merge in the new variable value,
* and write out an updated file. If the command is ALTER SYSTEM RESET ALL,
* we can skip reading the old file and just write an empty file.
*
* An LWLock is used to serialize updates of the configuration file.
*
* In case of an error, we leave the original automatic
* configuration file (PG_AUTOCONF_FILENAME) intact.
*/
/*
* SET command
*/
/*
* Get the value to assign for a VariableSetStmt, or NULL if it's RESET.
* The result is palloc'd.
*
* This is exported for use by actions such as ALTER ROLE SET.
*/
/*
* SetPGVariable - SET command exported as an easily-C-callable function.
*
* This provides access to SET TO value, as well as SET TO DEFAULT (expressed
* by passing args == NIL), but not SET FROM CURRENT functionality.
*/
/*
* SET command wrapped as a SQL callable function.
*/
/*
* Common code for DefineCustomXXXVariable subroutines: allocate the
* new variable's config struct and fill in generic fields.
*/
/*
* Common code for DefineCustomXXXVariable subroutines: insert the new
* variable into the GUC variable array, replacing any placeholder.
*/
/*
* Recursive subroutine for define_custom_variable: reapply non-reset values
*
* We recurse so that the values are applied in the same order as originally.
* At each recursion level, apply the upper-level value (passed in) in the
* fashion implied by the stack entry.
*/
/*
* SHOW command
*/
/*
* SHOW command
*/
/*
* SHOW ALL command
*/
/*
* Return an array of modified GUC options to show in EXPLAIN.
*
* We only report options related to query planning (marked with GUC_EXPLAIN),
* with values different from their built-in defaults.
*/
/*
* Return GUC variable value by name; optionally return canonical form of
* name. If the GUC is unset, then throw an error unless missing_ok is true,
* in which case return NULL. Return value is palloc'd (but *varname isn't).
*/
/*
* Return GUC variable value by variable number; optionally return canonical
* form of name. Return value is palloc'd.
*/
/*
* Return the total number of GUC variables
*/
/*
* show_config_by_name - equiv to SHOW X command but implemented as
* a function.
*/
/*
* show_config_by_name_missing_ok - equiv to SHOW X command but implemented as
* a function. If X does not exist, suppress the error and just return NULL
* if missing_ok is true.
*/
/*
* show_all_settings - equiv to SHOW ALL command but implemented as
* a Table Function.
*/
#define NUM_PG_SETTINGS_ATTS 17
/*
* show_all_file_settings
*
* Returns a table of all parameter settings in all configuration files
* which includes the config file pathname, the line number, a sequence number
* indicating the order in which the settings were encountered, the parameter
* name and value, a bool showing if the value could be applied, and possibly
* an associated error message. (For problems such as syntax errors, the
* parameter name/value might be NULL.)
*
* Note: no filtering is done here, instead we depend on the GRANT system
* to prevent unprivileged users from accessing this function or the view
* built on top of it.
*/
#define NUM_PG_FILE_SETTINGS_ATTS 7
#ifdef EXEC_BACKEND
/*
* These routines dump out all non-default GUC options into a binary
* file that is read by all exec'ed backends. The format is:
*
* variable name, string, null terminated
* variable value, string, null terminated
* variable sourcefile, string, null terminated (empty if none)
* variable sourceline, integer
* variable source, integer
* variable scontext, integer
*/
static void
write_one_nondefault_variable(FILE *fp, struct config_generic *gconf)
{
if (gconf->source == PGC_S_DEFAULT)
return;
fprintf(fp, "%s", gconf->name);
fputc(0, fp);
switch (gconf->vartype)
{
case PGC_BOOL:
{
struct config_bool *conf = (struct config_bool *) gconf;
if (*conf->variable)
fprintf(fp, "true");
else
fprintf(fp, "false");
}
break;
case PGC_INT:
{
struct config_int *conf = (struct config_int *) gconf;
fprintf(fp, "%d", *conf->variable);
}
break;
case PGC_REAL:
{
struct config_real *conf = (struct config_real *) gconf;
fprintf(fp, "%.17g", *conf->variable);
}
break;
case PGC_STRING:
{
struct config_string *conf = (struct config_string *) gconf;
fprintf(fp, "%s", *conf->variable);
}
break;
case PGC_ENUM:
{
struct config_enum *conf = (struct config_enum *) gconf;
fprintf(fp, "%s",
config_enum_lookup_by_value(conf, *conf->variable));
}
break;
}
fputc(0, fp);
if (gconf->sourcefile)
fprintf(fp, "%s", gconf->sourcefile);
fputc(0, fp);
fwrite(&gconf->sourceline, 1, sizeof(gconf->sourceline), fp);
fwrite(&gconf->source, 1, sizeof(gconf->source), fp);
fwrite(&gconf->scontext, 1, sizeof(gconf->scontext), fp);
}