guc_internal.h File Reference

#include "utils/guc.h"

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Functions
int	guc_name_compare (const char *namea, const char *nameb)
ConfigVariable *	ProcessConfigFileInternal (GucContext context, bool applySettings, int elevel)
void	record_config_file_error (const char *errmsg, const char *config_file, int lineno, ConfigVariable **head_p, ConfigVariable **tail_p)

Function Documentation

guc_name_compare()

int guc_name_compare	(	const char *	namea,
		const char *	nameb
	)

Definition at line 1265 of file guc.c.

{
    /*
     * The temptation to use strcasecmp() here must be resisted, because the
     * hash mapping has to remain stable across setlocale() calls. So, build
     * our own with a simple ASCII-only downcasing.
     */
    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;
}

Referenced by convert_GUC_name_for_parameter_acl(), find_option(), GetPGVariable(), GetPGVariableResultDesc(), guc_name_match(), guc_var_compare(), and replace_auto_config_value().

ProcessConfigFileInternal()

ConfigVariable* ProcessConfigFileInternal	(	GucContext	context,
		bool	applySettings,
		int	elevel
	)

Definition at line 275 of file guc.c.

{
    bool        error = false;
    bool        applying = false;
    const char *ConfFileWithError;
    ConfigVariable *item,
               *head,
               *tail;
    HASH_SEQ_STATUS status;
    GUCHashEntry *hentry;
 
    /* Parse the main config file into a list of option names and values */
    ConfFileWithError = ConfigFileName;
    head = tail = NULL;
 
    if (!ParseConfigFile(ConfigFileName, true,
                         NULL, 0, CONF_FILE_START_DEPTH, elevel,
                         &head, &tail))
    {
        /* Syntax error(s) detected in the file, so bail out */
        error = true;
        goto bail_out;
    }
 
    /*
     * Parse the PG_AUTOCONF_FILENAME file, if present, after the main file to
     * replace any parameters set by ALTER SYSTEM command.  Because this file
     * is in the data directory, we can't read it until the DataDir has been
     * set.
     */
    if (DataDir)
    {
        if (!ParseConfigFile(PG_AUTOCONF_FILENAME, false,
                             NULL, 0, CONF_FILE_START_DEPTH, elevel,
                             &head, &tail))
        {
            /* Syntax error(s) detected in the file, so bail out */
            error = true;
            ConfFileWithError = PG_AUTOCONF_FILENAME;
            goto bail_out;
        }
    }
    else
    {
        /*
         * If DataDir is not set, the PG_AUTOCONF_FILENAME file cannot be
         * read.  In this case, we don't want to accept any settings but
         * data_directory from postgresql.conf, because they might be
         * overwritten with settings in the PG_AUTOCONF_FILENAME file which
         * will be read later. OTOH, since data_directory isn't allowed in the
         * PG_AUTOCONF_FILENAME file, it will never be overwritten later.
         */
        ConfigVariable *newlist = NULL;
 
        /*
         * Prune all items except the last "data_directory" from the list.
         */
        for (item = head; item; item = item->next)
        {
            if (!item->ignore &&
                strcmp(item->name, "data_directory") == 0)
                newlist = item;
        }
 
        if (newlist)
            newlist->next = NULL;
        head = tail = newlist;
 
        /*
         * Quick exit if data_directory is not present in file.
         *
         * We need not do any further processing, in particular we don't set
         * PgReloadTime; that will be set soon by subsequent full loading of
         * the config file.
         */
        if (head == NULL)
            goto bail_out;
    }
 
    /*
     * Mark all extant GUC variables as not present in the config file. We
     * need this so that we can tell below which ones have been removed from
     * the file since we last processed it.
     */
    hash_seq_init(&status, guc_hashtab);
    while ((hentry = (GUCHashEntry *) hash_seq_search(&status)) != NULL)
    {
        struct config_generic *gconf = hentry->gucvar;
 
        gconf->status &= ~GUC_IS_IN_FILE;
    }
 
    /*
     * Check if all the supplied option names are valid, as an additional
     * quasi-syntactic check on the validity of the config file.  It is
     * important that the postmaster and all backends agree on the results of
     * this phase, else we will have strange inconsistencies about which
     * processes accept a config file update and which don't.  Hence, unknown
     * custom variable names have to be accepted without complaint.  For the
     * same reason, we don't attempt to validate the options' values here.
     *
     * In addition, the GUC_IS_IN_FILE flag is set on each existing GUC
     * variable mentioned in the file; and we detect duplicate entries in the
     * file and mark the earlier occurrences as ignorable.
     */
    for (item = head; item; item = item->next)
    {
        struct config_generic *record;
 
        /* Ignore anything already marked as ignorable */
        if (item->ignore)
            continue;
 
        /*
         * Try to find the variable; but do not create a custom placeholder if
         * it's not there already.
         */
        record = find_option(item->name, false, true, elevel);
 
        if (record)
        {
            /* If it's already marked, then this is a duplicate entry */
            if (record->status & GUC_IS_IN_FILE)
            {
                /*
                 * Mark the earlier occurrence(s) as dead/ignorable.  We could
                 * avoid the O(N^2) behavior here with some additional state,
                 * but it seems unlikely to be worth the trouble.
                 */
                ConfigVariable *pitem;
 
                for (pitem = head; pitem != item; pitem = pitem->next)
                {
                    if (!pitem->ignore &&
                        strcmp(pitem->name, item->name) == 0)
                        pitem->ignore = true;
                }
            }
            /* Now mark it as present in file */
            record->status |= GUC_IS_IN_FILE;
        }
        else if (!valid_custom_variable_name(item->name))
        {
            /* Invalid non-custom variable, so complain */
            ereport(elevel,
                    (errcode(ERRCODE_UNDEFINED_OBJECT),
                     errmsg("unrecognized configuration parameter \"%s\" in file \"%s\" line %d",
                            item->name,
                            item->filename, item->sourceline)));
            item->errmsg = pstrdup("unrecognized configuration parameter");
            error = true;
            ConfFileWithError = item->filename;
        }
    }
 
    /*
     * If we've detected any errors so far, we don't want to risk applying any
     * changes.
     */
    if (error)
        goto bail_out;
 
    /* Otherwise, set flag that we're beginning to apply changes */
    applying = true;
 
    /*
     * Check for variables having been removed from the config file, and
     * revert their reset values (and perhaps also effective values) to the
     * boot-time defaults.  If such a variable can't be changed after startup,
     * report that and continue.
     */
    hash_seq_init(&status, guc_hashtab);
    while ((hentry = (GUCHashEntry *) hash_seq_search(&status)) != NULL)
    {
        struct config_generic *gconf = hentry->gucvar;
        GucStack   *stack;
 
        if (gconf->reset_source != PGC_S_FILE ||
            (gconf->status & GUC_IS_IN_FILE))
            continue;
        if (gconf->context < PGC_SIGHUP)
        {
            /* The removal can't be effective without a restart */
            gconf->status |= GUC_PENDING_RESTART;
            ereport(elevel,
                    (errcode(ERRCODE_CANT_CHANGE_RUNTIME_PARAM),
                     errmsg("parameter \"%s\" cannot be changed without restarting the server",
                            gconf->name)));
            record_config_file_error(psprintf("parameter \"%s\" cannot be changed without restarting the server",
                                              gconf->name),
                                     NULL, 0,
                                     &head, &tail);
            error = true;
            continue;
        }
 
        /* No more to do if we're just doing show_all_file_settings() */
        if (!applySettings)
            continue;
 
        /*
         * Reset any "file" sources to "default", else set_config_option will
         * not override those settings.
         */
        if (gconf->reset_source == PGC_S_FILE)
            gconf->reset_source = PGC_S_DEFAULT;
        if (gconf->source == PGC_S_FILE)
            set_guc_source(gconf, PGC_S_DEFAULT);
        for (stack = gconf->stack; stack; stack = stack->prev)
        {
            if (stack->source == PGC_S_FILE)
                stack->source = PGC_S_DEFAULT;
        }
 
        /* Now we can re-apply the wired-in default (i.e., the boot_val) */
        if (set_config_option(gconf->name, NULL,
                              context, PGC_S_DEFAULT,
                              GUC_ACTION_SET, true, 0, false) > 0)
        {
            /* Log the change if appropriate */
            if (context == PGC_SIGHUP)
                ereport(elevel,
                        (errmsg("parameter \"%s\" removed from configuration file, reset to default",
                                gconf->name)));
        }
    }
 
    /*
     * Restore any variables determined by environment variables or
     * dynamically-computed defaults.  This is a no-op except in the case
     * where one of these had been in the config file and is now removed.
     *
     * In particular, we *must not* do this during the postmaster's initial
     * loading of the file, since the timezone functions in particular should
     * be run only after initialization is complete.
     *
     * XXX this is an unmaintainable crock, because we have to know how to set
     * (or at least what to call to set) every non-PGC_INTERNAL variable that
     * could potentially have PGC_S_DYNAMIC_DEFAULT or PGC_S_ENV_VAR source.
     */
    if (context == PGC_SIGHUP && applySettings)
    {
        InitializeGUCOptionsFromEnvironment();
        pg_timezone_abbrev_initialize();
        /* this selects SQL_ASCII in processes not connected to a database */
        SetConfigOption("client_encoding", GetDatabaseEncodingName(),
                        PGC_BACKEND, PGC_S_DYNAMIC_DEFAULT);
    }
 
    /*
     * Now apply the values from the config file.
     */
    for (item = head; item; item = item->next)
    {
        char       *pre_value = NULL;
        int         scres;
 
        /* Ignore anything marked as ignorable */
        if (item->ignore)
            continue;
 
        /* In SIGHUP cases in the postmaster, we want to report changes */
        if (context == PGC_SIGHUP && applySettings && !IsUnderPostmaster)
        {
            const char *preval = GetConfigOption(item->name, true, false);
 
            /* If option doesn't exist yet or is NULL, treat as empty string */
            if (!preval)
                preval = "";
            /* must dup, else might have dangling pointer below */
            pre_value = pstrdup(preval);
        }
 
        scres = set_config_option(item->name, item->value,
                                  context, PGC_S_FILE,
                                  GUC_ACTION_SET, applySettings, 0, false);
        if (scres > 0)
        {
            /* variable was updated, so log the change if appropriate */
            if (pre_value)
            {
                const char *post_value = GetConfigOption(item->name, true, false);
 
                if (!post_value)
                    post_value = "";
                if (strcmp(pre_value, post_value) != 0)
                    ereport(elevel,
                            (errmsg("parameter \"%s\" changed to \"%s\"",
                                    item->name, item->value)));
            }
            item->applied = true;
        }
        else if (scres == 0)
        {
            error = true;
            item->errmsg = pstrdup("setting could not be applied");
            ConfFileWithError = item->filename;
        }
        else
        {
            /* no error, but variable's active value was not changed */
            item->applied = true;
        }
 
        /*
         * We should update source location unless there was an error, since
         * even if the active value didn't change, the reset value might have.
         * (In the postmaster, there won't be a difference, but it does matter
         * in backends.)
         */
        if (scres != 0 && applySettings)
            set_config_sourcefile(item->name, item->filename,
                                  item->sourceline);
 
        if (pre_value)
            pfree(pre_value);
    }
 
    /* Remember when we last successfully loaded the config file. */
    if (applySettings)
        PgReloadTime = GetCurrentTimestamp();
 
bail_out:
    if (error && applySettings)
    {
        /* During postmaster startup, any error is fatal */
        if (context == PGC_POSTMASTER)
            ereport(ERROR,
                    (errcode(ERRCODE_CONFIG_FILE_ERROR),
                     errmsg("configuration file \"%s\" contains errors",
                            ConfFileWithError)));
        else if (applying)
            ereport(elevel,
                    (errcode(ERRCODE_CONFIG_FILE_ERROR),
                     errmsg("configuration file \"%s\" contains errors; unaffected changes were applied",
                            ConfFileWithError)));
        else
            ereport(elevel,
                    (errcode(ERRCODE_CONFIG_FILE_ERROR),
                     errmsg("configuration file \"%s\" contains errors; no changes were applied",
                            ConfFileWithError)));
    }
 
    /* Successful or otherwise, return the collected data list */
    return head;
}

References ConfigVariable::applied, bail_out(), CONF_FILE_START_DEPTH, ConfigFileName, config_generic::context, DataDir, ereport, errcode(), errmsg(), ConfigVariable::errmsg, ERROR, error(), ConfigVariable::filename, find_option(), GetConfigOption(), GetCurrentTimestamp(), GetDatabaseEncodingName(), GUC_ACTION_SET, guc_hashtab, GUC_IS_IN_FILE, GUC_PENDING_RESTART, GUCHashEntry::gucvar, hash_seq_init(), hash_seq_search(), ConfigVariable::ignore, InitializeGUCOptionsFromEnvironment(), IsUnderPostmaster, ConfigVariable::name, config_generic::name, ConfigVariable::next, ParseConfigFile(), pfree(), PG_AUTOCONF_FILENAME, pg_timezone_abbrev_initialize(), PGC_BACKEND, PGC_POSTMASTER, PGC_S_DEFAULT, PGC_S_DYNAMIC_DEFAULT, PGC_S_FILE, PGC_SIGHUP, PgReloadTime, guc_stack::prev, psprintf(), pstrdup(), record_config_file_error(), config_generic::reset_source, set_config_option(), set_config_sourcefile(), set_guc_source(), SetConfigOption(), guc_stack::source, config_generic::source, ConfigVariable::sourceline, config_generic::stack, config_generic::status, valid_custom_variable_name(), and ConfigVariable::value.

Referenced by show_all_file_settings().

record_config_file_error()

void record_config_file_error	(	const char *	errmsg,
		const char *	config_file,
		int	lineno,
		ConfigVariable **	head_p,
		ConfigVariable **	tail_p
	)

Referenced by ProcessConfigFileInternal().