From 94850ac604402371135e85de27a5d9074a947d4b Mon Sep 17 00:00:00 2001 From: Michael Paquier Date: Tue, 12 Apr 2022 18:14:28 +0900 Subject: [PATCH v2] Rework compression options of pg_receivewal Since babbbb5 and the introduction of LZ4 in pg_receivewal, the compression of archived WAL is controlled by two options: - --compression-method with "gzip", "none" or "lz4" as possible value. - --compress=N to specify a compression level, with a backward-incompatible change where a value of zero leads to a failure instead of no compression. This commit takes advantage of the previous refactoring done to rework the compression options of pg_receivewal: - --compression-method is removed. - --compress is extended to use the same grammar as pg_basebackup, as of a METHOD:DETAIL specification, where a METHOD is "gzip", "none" or "lz4" and a DETAIL is a comma-separated list of options, the only keyword supported is now "level" to control the compression level. If only an integer is specified as value of this option, "none" is implied for 0 and "gzip" is implied. So this brings back --compress to be backward-compatible with ~14, while still supporting LZ4. This has the advantage of centralizing the set of checks used by pg_basebackup. --- src/bin/pg_basebackup/pg_receivewal.c | 131 +++++++++++++------ src/bin/pg_basebackup/t/020_pg_receivewal.pl | 16 +-- doc/src/sgml/ref/pg_receivewal.sgml | 47 ++++--- 3 files changed, 121 insertions(+), 73 deletions(-) diff --git a/src/bin/pg_basebackup/pg_receivewal.c b/src/bin/pg_basebackup/pg_receivewal.c index ede1d4648d..f942883332 100644 --- a/src/bin/pg_basebackup/pg_receivewal.c +++ b/src/bin/pg_basebackup/pg_receivewal.c @@ -57,6 +57,8 @@ static XLogRecPtr endpos = InvalidXLogRecPtr; static void usage(void); +static void parse_compress_options(char *option, char **algorithm, + char **detail); static DIR *get_destination_dir(char *dest_folder); static void close_destination_dir(DIR *dest_dir, char *dest_folder); static XLogRecPtr FindStreamingStart(uint32 *tli); @@ -90,9 +92,8 @@ usage(void) printf(_(" --synchronous flush write-ahead log immediately after writing\n")); printf(_(" -v, --verbose output verbose messages\n")); printf(_(" -V, --version output version information, then exit\n")); - printf(_(" --compression-method=METHOD\n" - " method to compress logs\n")); - printf(_(" -Z, --compress=1-9 compress logs with given compression level\n")); + printf(_(" -Z, --compress=METHOD[:DETAIL]\n" + " compress as specified\n")); printf(_(" -?, --help show this help, then exit\n")); printf(_("\nConnection options:\n")); printf(_(" -d, --dbname=CONNSTR connection string\n")); @@ -108,6 +109,66 @@ usage(void) printf(_("%s home page: <%s>\n"), PACKAGE_NAME, PACKAGE_URL); } +/* + * Basic parsing of a value specified for -Z/--compress + * + * The parsing consists of a METHOD:DETAIL string fed later on to a more + * advanced routine in charge of proper validation checks. This only extracts + * METHOD and DETAIL. If only an integer is found, the method is implied by + * the value specified. + */ +static void +parse_compress_options(char *option, char **algorithm, char **detail) +{ + char *sep; + char *endp; + long result; + + /* + * Check whether the compression specification consists of a bare integer. + * + * For backward-compatibility, assume "none" if the integer found is zero + * and "gzip" otherwise. + */ + result = strtol(option, &endp, 10); + if (*endp == '\0') + { + if (result == 0) + { + *algorithm = pstrdup("none"); + *detail = NULL; + } + else + { + *algorithm = pstrdup("gzip"); + *detail = pstrdup(option); + } + return; + } + + /* + * Check whether there is a compression detail following the algorithm + * name. + */ + sep = strchr(option, ':'); + if (sep == NULL) + { + *algorithm = pstrdup(option); + *detail = NULL; + } + else + { + char *alg; + + alg = palloc((sep - option) + 1); + memcpy(alg, option, sep - option); + alg[sep - option] = '\0'; + + *algorithm = alg; + *detail = pstrdup(sep + 1); + } +} + /* * Check if the filename looks like a WAL file, letting caller know if this * WAL segment is partial and/or compressed. @@ -651,7 +712,6 @@ main(int argc, char **argv) {"if-not-exists", no_argument, NULL, 3}, {"synchronous", no_argument, NULL, 4}, {"no-sync", no_argument, NULL, 5}, - {"compression-method", required_argument, NULL, 6}, {NULL, 0, NULL, 0} }; @@ -660,6 +720,10 @@ main(int argc, char **argv) char *db_name; uint32 hi, lo; + pg_compress_specification compression_spec; + char *compression_detail = NULL; + char *compression_algorithm_str = "none"; + char *error_detail = NULL; pg_logging_init(argv[0]); progname = get_progname(argv[0]); @@ -728,9 +792,8 @@ main(int argc, char **argv) verbose++; break; case 'Z': - if (!option_parse_int(optarg, "-Z/--compress", 1, 9, - &compresslevel)) - exit(1); + parse_compress_options(optarg, &compression_algorithm_str, + &compression_detail); break; /* action */ case 1: @@ -748,17 +811,6 @@ main(int argc, char **argv) case 5: do_sync = false; break; - case 6: - if (pg_strcasecmp(optarg, "gzip") == 0) - compression_algorithm = PG_COMPRESSION_GZIP; - else if (pg_strcasecmp(optarg, "lz4") == 0) - compression_algorithm = PG_COMPRESSION_LZ4; - else if (pg_strcasecmp(optarg, "none") == 0) - compression_algorithm = PG_COMPRESSION_NONE; - else - pg_fatal("invalid value \"%s\" for option %s", - optarg, "--compression-method"); - break; default: /* getopt_long already emitted a complaint */ pg_log_error_hint("Try \"%s --help\" for more information.", progname); @@ -810,24 +862,30 @@ main(int argc, char **argv) exit(1); } - /* - * Compression-related options. + * Compression options */ + if (!parse_compress_algorithm(compression_algorithm_str, + &compression_algorithm)) + pg_fatal("unrecognized compression algorithm \"%s\"", + compression_algorithm_str); + + parse_compress_specification(compression_algorithm, compression_detail, + &compression_spec); + error_detail = validate_compress_specification(&compression_spec); + if (error_detail != NULL) + pg_fatal("invalid compression specification: %s", + error_detail); + + /* Extract the compression level, if found in the specification */ + if ((compression_spec.options & PG_COMPRESSION_OPTION_LEVEL) != 0) + compresslevel = compression_spec.level; + switch (compression_algorithm) { - case PG_COMPRESSION_NONE: - if (compresslevel != 0) - { - pg_log_error("cannot use --compress with --compression-method=%s", - "none"); - pg_log_error_hint("Try \"%s --help\" for more information.", progname); - exit(1); - } - break; case PG_COMPRESSION_GZIP: #ifdef HAVE_LIBZ - if (compresslevel == 0) + if ((compression_spec.options & PG_COMPRESSION_OPTION_LEVEL) == 0) { pg_log_info("no value specified for --compress, switching to default"); compresslevel = Z_DEFAULT_COMPRESSION; @@ -837,16 +895,11 @@ main(int argc, char **argv) "gzip"); #endif break; + case PG_COMPRESSION_NONE: + /* nothing to do */ + break; case PG_COMPRESSION_LZ4: -#ifdef USE_LZ4 - if (compresslevel != 0) - { - pg_log_error("cannot use --compress with --compression-method=%s", - "lz4"); - pg_log_error_hint("Try \"%s --help\" for more information.", progname); - exit(1); - } -#else +#ifndef USE_LZ4 pg_fatal("this build does not support compression with %s", "LZ4"); #endif diff --git a/src/bin/pg_basebackup/t/020_pg_receivewal.pl b/src/bin/pg_basebackup/t/020_pg_receivewal.pl index 8c38816b22..57e274cd34 100644 --- a/src/bin/pg_basebackup/t/020_pg_receivewal.pl +++ b/src/bin/pg_basebackup/t/020_pg_receivewal.pl @@ -35,11 +35,10 @@ $primary->command_fails( 'failure if --synchronous specified with --no-sync'); $primary->command_fails_like( [ - 'pg_receivewal', '-D', $stream_dir, '--compression-method', 'none', - '--compress', '1' + 'pg_receivewal', '-D', $stream_dir, '--compress', 'none:1', ], - qr/\Qpg_receivewal: error: cannot use --compress with --compression-method=none/, - 'failure if --compress specified with --compression-method=none'); + qr/\Qpg_receivewal: error: invalid compression specification: compression algorithm "none" does not accept a compression level/, + 'failure if --compress none:N (where N > 0)'); # Slot creation and drop my $slot_name = 'test'; @@ -93,15 +92,12 @@ SKIP: chomp($nextlsn); $primary->psql('postgres', 'INSERT INTO test_table VALUES (2);'); - # Note the trailing whitespace after the value of --compress, that is - # a valid value. $primary->command_ok( [ 'pg_receivewal', '-D', $stream_dir, '--verbose', '--endpos', $nextlsn, - '--compression-method', 'gzip', - '--compress', '1 ', + '--compress', 'gzip:1', '--no-loop' ], "streaming some WAL using ZLIB compression"); @@ -156,10 +152,10 @@ SKIP: 'pg_receivewal', '-D', $stream_dir, '--verbose', '--endpos', $nextlsn, - '--no-loop', '--compression-method', + '--no-loop', '--compress', 'lz4' ], - 'streaming some WAL using --compression-method=lz4'); + 'streaming some WAL using --compress=lz4'); # Verify that the stored files are generated with their expected # names. diff --git a/doc/src/sgml/ref/pg_receivewal.sgml b/doc/src/sgml/ref/pg_receivewal.sgml index b846213fb7..4fe9e1a874 100644 --- a/doc/src/sgml/ref/pg_receivewal.sgml +++ b/doc/src/sgml/ref/pg_receivewal.sgml @@ -263,15 +263,32 @@ PostgreSQL documentation - + + + + - Enables compression of write-ahead logs using the specified method. - Supported values are gzip, lz4 - (if PostgreSQL was compiled with - ), and none. + Enables compression of write-ahead logs. + + + The compression method can be set to gzip, + lz4 (if PostgreSQL + was compiled with ) or + none for no compression. + A compression detail string can optionally be specified. If the + detail string is an integer, it specifies the compression level. + Otherwise, it should be a comma-separated list of items, each of the + form keyword or keyword=value. + Currently, the only supported keyword is level. + + + If no compression level is specified, the default compression level + will be used. If only a level is specified without mentioning an + algorithm, gzip compression will be used if the + level is greater than 0, and no compression will be used if the level + is 0. - The suffix .gz will automatically be added to all filenames when using gzip, and the suffix @@ -279,24 +296,6 @@ PostgreSQL documentation - - - - - - - Specifies the compression level (1 through - 9, 1 being worst compression - and 9 being best compression) for WAL segments - compressed with gzip. - - - - This option requires to be - specified with gzip. - - - -- 2.35.1