psprintf.c File Reference

#include "postgres.h"
#include "utils/memutils.h"

Include dependency graph for psprintf.c:

Go to the source code of this file.

Functions
char *	psprintf (const char *fmt,...)
size_t	pvsnprintf (char *buf, size_t len, const char *fmt, va_list args)

Function Documentation

char* psprintf	(	const char *	fmt,
			...
	)

Definition at line 46 of file psprintf.c.

References generate_unaccent_rules::args, palloc(), pfree(), pvsnprintf(), and result.

Referenced by _mdfd_segpath(), anytime_typmodout(), anytimestamp_typmodout(), auth_failed(), AuxiliaryProcessMain(), BaseBackup(), brin_desummarize_range(), brin_metapage_info(), brin_page_type(), brin_summarize_range(), bt_metap(), bt_page_print_tuples(), bt_page_stats(), bt_target_page_check(), build_function_result_tupdesc_d(), build_server_final_message(), build_server_first_message(), cash_out(), cfopen_read(), cfopen_write(), complex_out(), convertOperatorReference(), create_script_for_cluster_analyze(), create_script_for_old_cluster_deletion(), create_tablespace_directories(), create_xlog_or_symlink(), datasegpath(), dblink_get_pkey(), defGetString(), destroy_tablespace_directories(), do_shell(), doputenv(), dumpAttrDef(), dumpConstraint(), dumpPolicy(), dumpPublicationTable(), dumpRule(), dumpTable(), dumpTrigger(), editFile(), exec_command_setenv(), expand_dynamic_library_name(), expand_tilde(), ExplainNode(), fetch_finfo_record(), format_type_internal(), get_role_password(), get_user_name(), GetDatabasePath(), gethba_options(), getObjectIdentityParts(), GetRelationPath(), GUCArrayAdd(), HandleParallelMessage(), initialize_data_directory(), initialize_environment(), initializeInput(), line_out(), load_libraries(), log_line_prefix(), LogicalRepSyncTableStart(), LogStreamerMain(), main(), md5_crypt_verify(), parse_hba_auth_opt(), parse_hba_line(), parseCommandLine(), perform_base_backup(), pg_be_scram_init(), pg_control_checkpoint(), pg_get_multixact_members(), pg_import_system_collations(), pg_logdir_ls(), pg_putenv(), pg_size_pretty_numeric(), pg_tablespace_databases(), pgstatindex_impl(), plain_crypt_verify(), printTypmod(), process_psqlrc_file(), ProcessStartupPacket(), prompt_for_password(), pset_value_string(), psql_start_test(), set_input(), set_null_conf(), set_tablespace_directory_suffix(), setup_pgdata(), spawn_process(), sql_exec_searchtables(), SS_make_initplan_from_plan(), SS_process_ctes(), StartupXLOG(), StoreQueryTuple(), substitute_libpath_macro(), tokenize_file(), tokenize_inc_file(), try_complete_step(), typenameTypeMod(), widget_out(), write_version_file(), XLogDumpDisplayRecord(), XLogDumpDisplayStats(), and xstrcat().

{
    size_t      len = 128;      /* initial assumption about buffer size */

    for (;;)
    {
        char       *result;
        va_list     args;
        size_t      newlen;

        /*
         * Allocate result buffer.  Note that in frontend this maps to malloc
         * with exit-on-error.
         */
        result = (char *) palloc(len);

        /* Try to format the data. */
        va_start(args, fmt);
        newlen = pvsnprintf(result, len, fmt, args);
        va_end(args);

        if (newlen < len)
            return result;      /* success */

        /* Release buffer and loop around to try again with larger len. */
        pfree(result);
        len = newlen;
    }
}

size_t pvsnprintf	(	char *	buf,
		size_t	len,
		const char *	fmt,
		va_list	args
	)

Definition at line 104 of file psprintf.c.

References _, Assert, elog, ereport, errcode(), errmsg(), ERROR, EXIT_FAILURE, MaxAllocSize, strerror(), and vsnprintf().

Referenced by ahprintf(), appendStringInfoVA(), archprintf(), psprintf(), and tarPrintf().

{
    int         nprinted;

    Assert(len > 0);

    errno = 0;

    /*
     * Assert check here is to catch buggy vsnprintf that overruns the
     * specified buffer length.  Solaris 7 in 64-bit mode is an example of a
     * platform with such a bug.
     */
#ifdef USE_ASSERT_CHECKING
    buf[len - 1] = '\0';
#endif

    nprinted = vsnprintf(buf, len, fmt, args);

    Assert(buf[len - 1] == '\0');

    /*
     * If vsnprintf reports an error other than ENOMEM, fail.  The possible
     * causes of this are not user-facing errors, so elog should be enough.
     */
    if (nprinted < 0 && errno != 0 && errno != ENOMEM)
    {
#ifndef FRONTEND
        elog(ERROR, "vsnprintf failed: %m");
#else
        fprintf(stderr, "vsnprintf failed: %s\n", strerror(errno));
        exit(EXIT_FAILURE);
#endif
    }

    /*
     * Note: some versions of vsnprintf return the number of chars actually
     * stored, not the total space needed as C99 specifies.  And at least one
     * returns -1 on failure.  Be conservative about believing whether the
     * print worked.
     */
    if (nprinted >= 0 && (size_t) nprinted < len - 1)
    {
        /* Success.  Note nprinted does not include trailing null. */
        return (size_t) nprinted;
    }

    if (nprinted >= 0 && (size_t) nprinted > len)
    {
        /*
         * This appears to be a C99-compliant vsnprintf, so believe its
         * estimate of the required space.  (If it's wrong, the logic will
         * still work, but we may loop multiple times.)  Note that the space
         * needed should be only nprinted+1 bytes, but we'd better allocate
         * one more than that so that the test above will succeed next time.
         *
         * In the corner case where the required space just barely overflows,
         * fall through so that we'll error out below (possibly after
         * looping).
         */
        if ((size_t) nprinted <= MaxAllocSize - 2)
            return nprinted + 2;
    }

    /*
     * Buffer overrun, and we don't know how much space is needed.  Estimate
     * twice the previous buffer size, but not more than MaxAllocSize; if we
     * are already at MaxAllocSize, choke.  Note we use this palloc-oriented
     * overflow limit even when in frontend.
     */
    if (len >= MaxAllocSize)
    {
#ifndef FRONTEND
        ereport(ERROR,
                (errcode(ERRCODE_PROGRAM_LIMIT_EXCEEDED),
                 errmsg("out of memory")));
#else
        fprintf(stderr, _("out of memory\n"));
        exit(EXIT_FAILURE);
#endif
    }

    if (len >= MaxAllocSize / 2)
        return MaxAllocSize;

    return len * 2;
}