From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from gate001.proxmox.com (gate001.proxmox.com [45.144.208.40]) by lore.proxmox.com (Postfix) with ESMTPS id 080211FF135 for ; Thu, 02 Jul 2026 13:51:30 +0200 (CEST) Received: from gate001.proxmox.com (localhost.localdomain [127.0.0.1]) by gate001.proxmox.com (Proxmox) with ESMTP id A3BC12141F; Thu, 02 Jul 2026 13:51:29 +0200 (CEST) From: Shan Shaji To: pbs-devel@lists.proxmox.com Subject: [PATCH proxmox-backup] fix #5748: docs: add `catalog.pcat1` format specification Date: Thu, 2 Jul 2026 13:51:15 +0200 Message-ID: <20260702115115.195035-1-s.shaji@proxmox.com> X-Mailer: git-send-email 2.47.3 MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Bm-Milter-Handled: 55990f41-d878-4baa-be0a-ee34c49e34d2 X-Bm-Transport-Timestamp: 1782993078736 X-SPAM-LEVEL: Spam detection results: 0 DMARC_MISSING 0.1 Missing DMARC policy KAM_DMARC_STATUS 0.01 Test Rule for DKIM or SPF Failure with Strict Alignment (newer systems) SPF_HELO_NONE 0.001 SPF: HELO does not publish an SPF Record SPF_PASS -0.001 SPF: sender matches SPF record Message-ID-Hash: 7PLOMY2LXGQHBJMNHX24EJ6I46GW2RDU X-Message-ID-Hash: 7PLOMY2LXGQHBJMNHX24EJ6I46GW2RDU X-MailFrom: s.shaji@proxmox.com X-Mailman-Rule-Misses: dmarc-mitigation; no-senders; approved; loop; banned-address; emergency; member-moderation; nonmember-moderation; administrivia; implicit-dest; max-recipients; max-size; news-moderation; no-subject; digests; suspicious-header X-Mailman-Version: 3.3.10 Precedence: list List-Id: Proxmox Backup Server development discussion List-Help: List-Owner: List-Post: List-Subscribe: List-Unsubscribe: Earlier proxmox catalog file format specification was not present inside the docs. fixed it by adding format specification under file formats. Fixes: https://bugzilla.proxmox.com/show_bug.cgi?id=5748 Signed-off-by: Shan Shaji --- changes since RFC: Thanks @Christian Ebner - Changed from graph to table layout. - Explicity mention about the variable length types. - Denoted the root start offset as u64. - Add text description for each field. docs/file-formats.rst | 65 +++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 65 insertions(+) diff --git a/docs/file-formats.rst b/docs/file-formats.rst index ed3250d11..52cb20ee0 100644 --- a/docs/file-formats.rst +++ b/docs/file-formats.rst @@ -23,6 +23,71 @@ overhead introduced by the file payloads. .. graphviz:: meta-format-overview.dot +.. _pcat1-format: + +Proxmox Catalog File Format (``.pcat1``) +---------------------------------------- + +The asterisk notation indicates variable-length encoding: u64* denotes an unsigned variable-length encoded integer, while i64* +denotes a signed variable-length encoded integer. + +.. list-table:: + :widths: auto + + * - ``MAGIC: [u8; 8]`` + - ``[145, 253, 96, 249, 196, 103, 88, 213]``. + * - ``TABLE_LENGTH: u64*`` + - Total length of the contents inside the Directory. + * - ``ENTRY_COUNT: u64*`` + - Count of entries present inside the Directory. + * - ``ENTRIES`` + - Concatinated ``ENTRY`` structures (see the ``ENTRY`` :ref:`layout ` .) Repeated ``ENTRY_COUNT`` times. + * - ... + - Further concatination of sequential directory blocks (Table Length, Entry Count and Entries). + * - ``ROOT_START_OFFSET: u64`` + - Root marker (/) start offset. Stored as **little-endian** + +.. _entry-layout: + +Except for files and directories, no additional payload is stored beyond the name and its length inside an ENTRY. + +.. list-table:: + :widths: auto + + * - ``ENTRY_TYPE: u8`` + - The type of entry (see entry :ref:`types `). + * - ``NAME_LENGTH: u64*`` + - Length of file or directory name. Stored as variable length encoded u64. + * - ``NAME: [u8]`` + - The raw UTF-8 string bytes of the name. + * - ``PAYLOAD`` + - Bytes based on ``ENTRY_TYPE`` + + * **Directory ('d')**: ``offset_back: u64*`` (Child-to-Parent offset distance) + * **File ('f')**: ``size: u64*`` followed by ``mtime: i64*`` +.. _entry-types: + +Entry Types: + +.. list-table:: + :widths: auto + + * - ``d`` + - Directory + * - ``f`` + - File + * - ``l`` + - Symlink + * - ``h`` + - Hardlink + * - ``b`` + - Block device + * - ``c`` + - Char device + * - ``p`` + - FIFO + * - ``s`` + - Socket .. _ppxar-format: Proxmox File Archive Format - Payload (``.ppxar``) -- 2.47.3