kernel/git - git - PowerEL Git System

Commit Graph

Author	SHA1	Message	Date
Derrick Stolee	d96075428a	multi-pack-index: use hash version byte Similar to the commit-graph format, the multi-pack-index format has a byte in the header intended to track the hash version used to write the file. This allows one to interpret the hash length without having the context of the repository config specifying the hash length. This was not modified as part of the SHA-256 work because the hash length was automatically up-shifted due to that config. Since we have this byte available, we can make the file formats more obviously incompatible instead of relying on other context from the repository. Add a new oid_version() method in midx.c similar to the one in commit-graph.c. This is specifically made separate from that implementation to avoid artificially linking the formats. The test impact requires a few more things than the corresponding change in the commit-graph format. Specifically, 'test-tool read-midx' was not writing anything about this header value to output. Since the value available in 'struct multi_pack_index' is hash_len instead of a version value, we output "20" or "32" instead of "1" or "2". Since we want a user to not have their Git commands fail if their multi-pack-index has the incorrect hash version compared to the repository's hash version, we relax the die() to an error() in load_multi_pack_index(). This has some effect on 'git multi-pack-index verify' as we need to check that a failed parse of a file that exists is actually a verify error. For that test that checks the hash version matches, we change the corrupted byte from "2" to "3" to ensure the test fails for both hash algorithms. Helped-by: brian m. carlson <sandals@crustytoothpaste.net> Signed-off-by: Derrick Stolee <dstolee@microsoft.com> Reviewed-by: brian m. carlson <sandals@crustytoothpaste.net> Signed-off-by: Junio C Hamano <gitster@pobox.com>	5 years ago
brian m. carlson	17420eafa9	docs: document SHA-256 pack and indices Now that we have SHA-256 support for packs and indices, let's document that in SHA-256 repositories, we use SHA-256 instead of SHA-1 for object names and checksums. Instead of duplicating this information throughout the document, let's just document that in SHA-1 repositories, we use SHA-1 for these purposes, and in SHA-256 repositories, we use SHA-256. Signed-off-by: brian m. carlson <sandals@crustytoothpaste.net> Signed-off-by: Junio C Hamano <gitster@pobox.com>	5 years ago
Johannes Berg	eb31044ff7	pack-format: correct multi-pack-index description The description of the multi-pack-index contains a small bug, if all offsets are < 2^32 then there will be no LOFF chunk, not only if they're all < 2^31 (since the highest bit is only needed as the "LOFF-escape" when that's actually needed.) Correct this, and clarify that in that case only offsets up to 2^31-1 can be stored in the OOFF chunk. Signed-off-by: Johannes Berg <johannes@sipsolutions.net> Acked-by: Derrick Stolee <dstolee@microsoft.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>	5 years ago
Derrick Stolee	662148c435	midx: write object offsets The final pair of chunks for the multi-pack-index file stores the object offsets. We default to using 32-bit offsets as in the pack-index version 1 format, but if there exists an offset larger than 32-bits, we use a trick similar to the pack-index version 2 format by storing all offsets at least 2^31 in a 64-bit table; we use the 32-bit table to point into that 64-bit table as necessary. We only store these 64-bit offsets if necessary, so create a test that manipulates a version 2 pack-index to fake a large offset. This allows us to test that the large offset table is created, but the data does not match the actual packfile offsets. The multi-pack-index offset does match the (corrupted) pack-index offset, so a future feature will compare these offsets during a 'verify' step. Signed-off-by: Derrick Stolee <dstolee@microsoft.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>	7 years ago
Derrick Stolee	d7cacf29cc	midx: write object id fanout chunk Signed-off-by: Derrick Stolee <dstolee@microsoft.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>	7 years ago
Derrick Stolee	0d5b3a5ef7	midx: write object ids in a chunk Signed-off-by: Derrick Stolee <dstolee@microsoft.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>	7 years ago
Derrick Stolee	32f3c541e3	multi-pack-index: write pack names in chunk The multi-pack-index needs to track which packfiles it indexes. Store these in our first required chunk. Since filenames are not well structured, add padding to keep good alignment in later chunks. Modify the 'git multi-pack-index read' subcommand to output the existence of the pack-file name chunk. Modify t5319-multi-pack-index.sh to reflect this new output and the new expected number of chunks. Defense in depth: A pattern we are using in the multi-pack-index feature is to verify the data as we write it. We want to ensure we never write invalid data to the multi-pack-index. There are many checks that verify that the values we are writing fit the format definitions. This mainly helps developers while working on the feature, but it can also identify issues that only appear when dealing with very large data sets. These large sets are hard to encode into test cases. Signed-off-by: Derrick Stolee <dstolee@microsoft.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>	7 years ago
Derrick Stolee	e0d1bcf825	multi-pack-index: add format details The multi-pack-index feature generalizes the existing pack-index feature by indexing objects across multiple pack-files. Describe the basic file format, using a 12-byte header followed by a lookup table for a list of "chunks" which will be described later. The file ends with a footer containing a checksum using the hash algorithm. The header allows later versions to create breaking changes by advancing the version number. We can also change the hash algorithm using a different version value. We will add the individual chunk format information as we introduce the code that writes that information. Signed-off-by: Derrick Stolee <dstolee@microsoft.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>	7 years ago
Nguyễn Thái Ngọc Duy	011b648646	pack-format.txt: more details on pack file format The current document mentions OBJ_* constants without their actual values. A git developer would know these are from cache.h but that's not very friendly to a person who wants to read this file to implement a pack file parser. Similarly, the deltified representation is not documented at all (the "document" is basically patch-delta.c). Translate that C code to English with a bit more about what ofs-delta and ref-delta mean. Signed-off-by: Nguyễn Thái Ngọc Duy <pclouds@gmail.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>	7 years ago
Thomas Ackermann	d5fa1f1a69	The name of the hash function is "SHA-1", not "SHA1" Use "SHA-1" instead of "SHA1" whenever we talk about the hash function. When used as a programming symbol, we keep "SHA1". Signed-off-by: Thomas Ackermann <th.acker@arcor.de> Signed-off-by: Junio C Hamano <gitster@pobox.com>	12 years ago
Stefan Saasen	06cb843fea	Documentation: distinguish between ref and offset deltas in pack-format `eb32d236` introduced the OBJ_OFS_DELTA object that uses a relative offset to identify the base object instead of the 20-byte SHA1 reference. The pack file documentation only mentions the SHA1 based reference in its description of the deltified object entry. Update the pack format documentation to clarify that the deltified object representation refers to its base using either a relative negative offset or the absolute SHA1 identifier. Signed-off-by: Stefan Saasen <ssaasen@atlassian.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>	12 years ago
Thomas Ackermann	48a8c26c62	Documentation: avoid poor-man's small caps GIT In the earlier days, we used to spell the name of the system as GIT, to simulate as if it were typeset with capital G and IT in small caps. Later we stopped doing so at around 1.6.5 days. Let's stop doing so throughout the documentation. The name to refer to the whole system (and the concept it embodies) is "Git"; the command end-users type is "git". And document this in the coding guideline. Signed-off-by: Thomas Ackermann <th.acker@arcor.de> Signed-off-by: Junio C Hamano <gitster@pobox.com>	12 years ago
Thomas Ackermann	5316c8e939	Documentation/technical: convert plain text files to asciidoc These were not originally meant for asciidoc, but they are already so close. Mark them up in asciidoc. Signed-off-by: Thomas Ackermann <th.acker@arcor.de> Signed-off-by: Junio C Hamano <gitster@pobox.com>	13 years ago
Peter Eriksen	9de328fea9	Add description of OFS_DELTA to the pack format description Signed-off-by: Peter Eriksen <s022018@student.dtu.dk> Acked-by: Shawn O. Pearce <spearce@spearce.org> Signed-off-by: Junio C Hamano <gitster@pobox.com>	17 years ago
Ralf Wildenhues	f1cdcc70dc	Documentation: typofix Signed-off-by: Ralf Wildenhues <Ralf.Wildenhues@gmx.de> Signed-off-by: Junio C Hamano <gitster@pobox.com>	17 years ago
linux@horizon.com	71362bd552	Documentation: describe pack idx v2 Lifted from the log message of `c553ca25bd` (pack-objects: learn about pack index version 2). Acked-by: Nicolas Pitre <nico@cam.org> Signed-off-by: Junio C Hamano <gitster@pobox.com>	18 years ago
Junio C Hamano	a6080a0a44	War on whitespace This uses "git-apply --whitespace=strip" to fix whitespace errors that have crept in to our source files over time. There are a few files that need to have trailing whitespaces (most notably, test vectors). The results still passes the test, and build result in Documentation/ area is unchanged. Signed-off-by: Junio C Hamano <gitster@pobox.com>	18 years ago
Peter Eriksen	979ea5856c	Documentation/pack-format.txt: Clear up description of types. Signed-off-by: Peter Eriksen <s022018@student.dtu.dk> Signed-off-by: Junio C Hamano <junkio@cox.net>	18 years ago
Shawn Pearce	1361fa3e49	Improved pack format documentation. While trying to implement a pack reader in Java I was mislead by some facts listed in this documentation as well as found a few details to be missing about the pack header. Signed-off-by: Shawn O. Pearce <spearce@spearce.org> Signed-off-by: Junio C Hamano <junkio@cox.net>	19 years ago
Junio C Hamano	9760662f1a	Add Documentation/technical/pack-format.txt ... along with the previous one, pack-heuristics, by popular demand. Signed-off-by: Junio C Hamano <junkio@cox.net>	19 years ago

22 Commits (0df670bc0b8b5499859829ba0889ce96a75304a6)