From 2b3fec35c1070e187ee71ee7fdaa76bef09e076f Mon Sep 17 00:00:00 2001 From: Amul Sul Date: Tue, 17 Feb 2026 14:51:11 +0530 Subject: [PATCH v19 1/4] Move tar detection and compression logic to common. Consolidate tar archive identification and compression-type detection logic into a shared location. Currently used by pg_basebackup and pg_verifybackup, this functionality is also required for upcoming pg_waldump enhancements. This change promotes code reuse and simplifies maintenance across frontend tools. Author: Amul Sul Reviewed-by: Robert Haas Reviewed-by: Jakub Wartak Reviewed-by: Chao Li Reviewed-by: Euler Taveira Reviewed-by: Andrew Dunstan discussion: https://postgr.es/m/CAAJ_b94bqdWN3h2J-PzzzQ2Npbwct5ZQHggn_QoYGhC2rn-=WQ@mail.gmail.com --- src/bin/pg_basebackup/pg_basebackup.c | 36 +++++++---------------- src/bin/pg_verifybackup/pg_verifybackup.c | 12 +------- src/common/compression.c | 30 +++++++++++++++++++ src/include/common/compression.h | 2 ++ 4 files changed, 44 insertions(+), 36 deletions(-) diff --git a/src/bin/pg_basebackup/pg_basebackup.c b/src/bin/pg_basebackup/pg_basebackup.c index fa169a8d642..c1a4672aa6f 100644 --- a/src/bin/pg_basebackup/pg_basebackup.c +++ b/src/bin/pg_basebackup/pg_basebackup.c @@ -1070,12 +1070,9 @@ CreateBackupStreamer(char *archive_name, char *spclocation, astreamer *manifest_inject_streamer = NULL; bool inject_manifest; bool is_tar, - is_tar_gz, - is_tar_lz4, - is_tar_zstd, is_compressed_tar; + pg_compress_algorithm compressed_tar_algorithm; bool must_parse_archive; - int archive_name_len = strlen(archive_name); /* * Normally, we emit the backup manifest as a separate file, but when @@ -1084,24 +1081,13 @@ CreateBackupStreamer(char *archive_name, char *spclocation, */ inject_manifest = (format == 't' && strcmp(basedir, "-") == 0 && manifest); - /* Is this a tar archive? */ - is_tar = (archive_name_len > 4 && - strcmp(archive_name + archive_name_len - 4, ".tar") == 0); - - /* Is this a .tar.gz archive? */ - is_tar_gz = (archive_name_len > 7 && - strcmp(archive_name + archive_name_len - 7, ".tar.gz") == 0); - - /* Is this a .tar.lz4 archive? */ - is_tar_lz4 = (archive_name_len > 8 && - strcmp(archive_name + archive_name_len - 8, ".tar.lz4") == 0); - - /* Is this a .tar.zst archive? */ - is_tar_zstd = (archive_name_len > 8 && - strcmp(archive_name + archive_name_len - 8, ".tar.zst") == 0); + /* Check whether it is a tar archive and its compression type */ + is_tar = parse_tar_compress_algorithm(archive_name, + &compressed_tar_algorithm); /* Is this any kind of compressed tar? */ - is_compressed_tar = is_tar_gz || is_tar_lz4 || is_tar_zstd; + is_compressed_tar = (is_tar && + compressed_tar_algorithm != PG_COMPRESSION_NONE); /* * Injecting the manifest into a compressed tar file would be possible if @@ -1128,7 +1114,7 @@ CreateBackupStreamer(char *archive_name, char *spclocation, (spclocation == NULL && writerecoveryconf)); /* At present, we only know how to parse tar archives. */ - if (must_parse_archive && !is_tar && !is_compressed_tar) + if (must_parse_archive && !is_tar) { pg_log_error("cannot parse archive \"%s\"", archive_name); pg_log_error_detail("Only tar archives can be parsed."); @@ -1263,13 +1249,13 @@ CreateBackupStreamer(char *archive_name, char *spclocation, * If the user has requested a server compressed archive along with * archive extraction at client then we need to decompress it. */ - if (format == 'p') + if (format == 'p' && is_compressed_tar) { - if (is_tar_gz) + if (compressed_tar_algorithm == PG_COMPRESSION_GZIP) streamer = astreamer_gzip_decompressor_new(streamer); - else if (is_tar_lz4) + else if (compressed_tar_algorithm == PG_COMPRESSION_LZ4) streamer = astreamer_lz4_decompressor_new(streamer); - else if (is_tar_zstd) + else if (compressed_tar_algorithm == PG_COMPRESSION_ZSTD) streamer = astreamer_zstd_decompressor_new(streamer); } diff --git a/src/bin/pg_verifybackup/pg_verifybackup.c b/src/bin/pg_verifybackup/pg_verifybackup.c index cbc9447384f..31f606c45b1 100644 --- a/src/bin/pg_verifybackup/pg_verifybackup.c +++ b/src/bin/pg_verifybackup/pg_verifybackup.c @@ -941,17 +941,7 @@ precheck_tar_backup_file(verifier_context *context, char *relpath, } /* Now, check the compression type of the tar */ - if (strcmp(suffix, ".tar") == 0) - compress_algorithm = PG_COMPRESSION_NONE; - else if (strcmp(suffix, ".tgz") == 0) - compress_algorithm = PG_COMPRESSION_GZIP; - else if (strcmp(suffix, ".tar.gz") == 0) - compress_algorithm = PG_COMPRESSION_GZIP; - else if (strcmp(suffix, ".tar.lz4") == 0) - compress_algorithm = PG_COMPRESSION_LZ4; - else if (strcmp(suffix, ".tar.zst") == 0) - compress_algorithm = PG_COMPRESSION_ZSTD; - else + if (!parse_tar_compress_algorithm(suffix, &compress_algorithm)) { report_backup_error(context, "file \"%s\" is not expected in a tar format backup", diff --git a/src/common/compression.c b/src/common/compression.c index 92cd4ec7a0d..fb27501d297 100644 --- a/src/common/compression.c +++ b/src/common/compression.c @@ -41,6 +41,36 @@ static int expect_integer_value(char *keyword, char *value, static bool expect_boolean_value(char *keyword, char *value, pg_compress_specification *result); +/* + * Look up a compression algorithm by archive file extension. Returns true and + * sets *algorithm if the name is recognized. Otherwise returns false. + */ +bool +parse_tar_compress_algorithm(const char *fname, pg_compress_algorithm *algorithm) +{ + int fname_len = strlen(fname); + + if (fname_len >= 4 && + strcmp(fname + fname_len - 4, ".tar") == 0) + *algorithm = PG_COMPRESSION_NONE; + else if (fname_len >= 4 && + strcmp(fname + fname_len - 4, ".tgz") == 0) + *algorithm = PG_COMPRESSION_GZIP; + else if (fname_len >= 7 && + strcmp(fname + fname_len - 7, ".tar.gz") == 0) + *algorithm = PG_COMPRESSION_GZIP; + else if (fname_len >= 8 && + strcmp(fname + fname_len - 8, ".tar.lz4") == 0) + *algorithm = PG_COMPRESSION_LZ4; + else if (fname_len >= 8 && + strcmp(fname + fname_len - 8, ".tar.zst") == 0) + *algorithm = PG_COMPRESSION_ZSTD; + else + return false; + + return true; +} + /* * Look up a compression algorithm by name. Returns true and sets *algorithm * if the name is recognized. Otherwise returns false. diff --git a/src/include/common/compression.h b/src/include/common/compression.h index 6c745b90066..f99c747cdd3 100644 --- a/src/include/common/compression.h +++ b/src/include/common/compression.h @@ -41,6 +41,8 @@ typedef struct pg_compress_specification extern void parse_compress_options(const char *option, char **algorithm, char **detail); +extern bool parse_tar_compress_algorithm(const char *fname, + pg_compress_algorithm *algorithm); extern bool parse_compress_algorithm(char *name, pg_compress_algorithm *algorithm); extern const char *get_compress_algorithm_name(pg_compress_algorithm algorithm); -- 2.47.1