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2019-08-09Merge branch 'ds/commit-graph-incremental'Libravatar Junio C Hamano1-5/+7
Leakfix. * ds/commit-graph-incremental: commit-graph: release strbufs after use
2019-08-07commit-graph: release strbufs after useLibravatar René Scharfe1-5/+7
Signed-off-by: René Scharfe <l.s.r@web.de> Acked-by: Derrick Stolee <dstolee@microsoft.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2019-08-05commit-graph: fix bug around octopus mergesLibravatar Derrick Stolee1-1/+1
In 1771be90 "commit-graph: merge commit-graph chains" (2019-06-18), the method sort_and_scan_merged_commits() was added to merge the commit lists of two commit-graph files in the incremental format. Unfortunately, there was an off-by-one error in that method around incrementing num_extra_edges, which leads to an incorrect offset for the base graph chunk. When we store an octopus merge in the commit-graph file, we store the first parent in the normal place, but use the second parent position to point into the "extra edges" chunk where the remaining parents exist. This means we should be adding "num_parents - 1" edges to this list, not "num_parents - 2". That is the basic error. The reason this was not caught in the test suite is more subtle. In 5324-split-commit-graph.sh, we test creating an octopus merge and adding it to the tip of a commit-graph chain, then verify the result. This _should_ have caught the problem, except that when we load the commit-graph files we were overly careful to not fail when the commit-graph chain does not match. This care was on purpose to avoid race conditions as one process reads the chain and another process modifies it. In such a case, the reading process outputs the following message to stderr: warning: commit-graph chain does not match These warnings are output in the test suite, but ignored. By checking the stderr of `git commit-graph verify` to include the expected progress output, it will now catch this error. Signed-off-by: Derrick Stolee <dstolee@microsoft.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2019-07-19Merge branch 'ds/commit-graph-incremental'Libravatar Junio C Hamano1-49/+774
The commits in a repository can be described by multiple commit-graph files now, which allows the commit-graph files to be updated incrementally. * ds/commit-graph-incremental: commit-graph: test verify across alternates commit-graph: normalize commit-graph filenames commit-graph: test --split across alternate without --split commit-graph: test octopus merges with --split commit-graph: clean up chains after flattened write commit-graph: verify chains with --shallow mode commit-graph: create options for split files commit-graph: expire commit-graph files commit-graph: allow cross-alternate chains commit-graph: merge commit-graph chains commit-graph: add --split option to builtin commit-graph: write commit-graph chains commit-graph: rearrange chunk count logic commit-graph: add base graphs chunk commit-graph: load commit-graph chains commit-graph: rename commit_compare to oid_compare commit-graph: prepare for commit-graph chains commit-graph: document commit-graph chains
2019-07-09Merge branch 'jk/oidhash'Libravatar Junio C Hamano1-1/+1
Code clean-up to remove hardcoded SHA-1 hash from many places. * jk/oidhash: hashmap: convert sha1hash() to oidhash() hash.h: move object_id definition from cache.h khash: rename oid helper functions khash: drop sha1-specific map types pack-bitmap: convert khash_sha1 maps into kh_oid_map delta-islands: convert island_marks khash to use oids khash: rename kh_oid_t to kh_oid_set khash: drop broken oid_map typedef object: convert create_object() to use object_id object: convert internal hash_obj() to object_id object: convert lookup_object() to use object_id object: convert lookup_unknown_object() to use object_id pack-objects: convert locate_object_entry_hash() to object_id pack-objects: convert packlist_find() to use object_id pack-bitmap-write: convert some helpers to use object_id upload-pack: rename a "sha1" variable to "oid" describe: fix accidental oid/hash type-punning
2019-07-09Merge branch 'ds/close-object-store'Libravatar Junio C Hamano1-4/+4
The commit-graph file is now part of the "files that the runtime may keep open file descriptors on, all of which would need to be closed when done with the object store", and the file descriptor to an existing commit-graph file now is closed before "gc" finalizes a new instance to replace it. * ds/close-object-store: packfile: rename close_all_packs to close_object_store packfile: close commit-graph in close_all_packs commit-graph: use raw_object_store when closing
2019-07-09Merge branch 'ds/commit-graph-write-refactor'Libravatar Junio C Hamano1-271/+336
Renamed from commit-graph-format-v2 and changed scope. * ds/commit-graph-write-refactor: commit-graph: extract write_commit_graph_file() commit-graph: extract copy_oids_to_commits() commit-graph: extract count_distinct_commits() commit-graph: extract fill_oids_from_all_packs() commit-graph: extract fill_oids_from_commit_hex() commit-graph: extract fill_oids_from_packs() commit-graph: create write_commit_graph_context commit-graph: remove Future Work section commit-graph: collapse parameters into flags commit-graph: return with errors during write commit-graph: fix the_repository reference
2019-06-20object: convert create_object() to use object_idLibravatar Jeff King1-1/+1
There are no callers left of create_object() that aren't just passing us the "hash" member of a "struct object_id". Let's take the whole struct, which gets us closer to removing all raw sha1 variables. Signed-off-by: Jeff King <peff@peff.net> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2019-06-19commit-graph: normalize commit-graph filenamesLibravatar Derrick Stolee1-7/+23
When writing commit-graph files, we append path data to an object directory, which may be specified by the user via the '--object-dir' option. If the user supplies a trailing slash, or some other alternative path format, the resulting path may be usable for writing to the correct location. However, when expiring graph files from the <obj-dir>/info/commit-graphs directory during a write, we need to compare paths with exact string matches. Normalize the commit-graph filenames to avoid ambiguity. This creates extra allocations, but this is a constant multiple of the number of commit-graph files, which should be a number in the single digits. Further normalize the object directory in the context. Due to a comparison between g->obj_dir and ctx->obj_dir in split_graph_merge_strategy(), a trailing slash would prevent any merging of layers within the same object directory. The check is there to ensure we do not merge across alternates. Update the tests to include a case with this trailing slash problem. Signed-off-by: Derrick Stolee <dstolee@microsoft.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2019-06-19commit-graph: clean up chains after flattened writeLibravatar Derrick Stolee1-3/+9
If we write a commit-graph file without the split option, then we write to $OBJDIR/info/commit-graph and start to ignore the chains in $OBJDIR/info/commit-graphs/. Unlink the commit-graph-chain file and expire the graph-{hash}.graph files in $OBJDIR/info/commit-graphs/ during every write. Signed-off-by: Derrick Stolee <dstolee@microsoft.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2019-06-19commit-graph: verify chains with --shallow modeLibravatar Derrick Stolee1-3/+12
If we wrote a commit-graph chain, we only modified the tip file in the chain. It is valuable to verify what we wrote, but not waste time checking files we did not write. Add a '--shallow' option to the 'git commit-graph verify' subcommand and check that it does not read the base graph in a two-file chain. Making the verify subcommand read from a chain of commit-graphs takes some rearranging of the builtin code. Signed-off-by: Derrick Stolee <dstolee@microsoft.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2019-06-19commit-graph: create options for split filesLibravatar Derrick Stolee1-11/+24
The split commit-graph feature is now fully implemented, but needs some more run-time configurability. Allow direct callers to 'git commit-graph write --split' to specify the values used in the merge strategy and the expire time. Update the documentation to specify these values. Signed-off-by: Derrick Stolee <dstolee@microsoft.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2019-06-19commit-graph: expire commit-graph filesLibravatar Derrick Stolee1-0/+69
As we merge commit-graph files in a commit-graph chain, we should clean up the files that are no longer used. This change introduces an 'expiry_window' value to the context, which is always zero (for now). We then check the modified time of each graph-{hash}.graph file in the $OBJDIR/info/commit-graphs folder and unlink the files that are older than the expiry_window. Since this is always zero, this immediately clears all unused graph files. We will update the value to match a config setting in a future change. Signed-off-by: Derrick Stolee <dstolee@microsoft.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2019-06-19commit-graph: allow cross-alternate chainsLibravatar Derrick Stolee1-11/+45
In an environment like a fork network, it is helpful to have a commit-graph chain that spans both the base repo and the fork repo. The fork is usually a small set of data on top of the large repo, but sometimes the fork is much larger. For example, git-for-windows/git has almost double the number of commits as git/git because it rebases its commits on every major version update. To allow cross-alternate commit-graph chains, we need a few pieces: 1. When looking for a graph-{hash}.graph file, check all alternates. 2. When merging commit-graph chains, do not merge across alternates. 3. When writing a new commit-graph chain based on a commit-graph file in another object directory, do not allow success if the base file has of the name "commit-graph" instead of "commit-graphs/graph-{hash}.graph". Signed-off-by: Derrick Stolee <dstolee@microsoft.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2019-06-19commit-graph: merge commit-graph chainsLibravatar Derrick Stolee1-33/+147
When searching for a commit in a commit-graph chain of G graphs with N commits, the search takes O(G log N) time. If we always add a new tip graph with every write, the linear G term will start to dominate and slow the lookup process. To keep lookups fast, but also keep most incremental writes fast, create a strategy for merging levels of the commit-graph chain. The strategy is detailed in the commit-graph design document, but is summarized by these two conditions: 1. If the number of commits we are adding is more than half the number of commits in the graph below, then merge with that graph. 2. If we are writing more than 64,000 commits into a single graph, then merge with all lower graphs. The numeric values in the conditions above are currently constant, but can become config options in a future update. As we merge levels of the commit-graph chain, check that the commits still exist in the repository. A garbage-collection operation may have removed those commits from the object store and we do not want to persist them in the commit-graph chain. This is a non-issue if the 'git gc' process wrote a new, single-level commit-graph file. After we merge levels, the old graph-{hash}.graph files are no longer referenced by the commit-graph-chain file. We will expire these files in a future change. Signed-off-by: Derrick Stolee <dstolee@microsoft.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2019-06-19commit-graph: add --split option to builtinLibravatar Derrick Stolee1-5/+9
Add a new "--split" option to the 'git commit-graph write' subcommand. This option allows the optional behavior of writing a commit-graph chain. The current behavior will add a tip commit-graph containing any commits that are not in the existing commit-graph or commit-graph chain. Later changes will allow merging the chain and expiring out-dated files. Add a new test script (t5324-split-commit-graph.sh) that demonstrates this behavior. Helped-by: Johannes Schindelin <Johannes.Schindelin@gmx.de> Signed-off-by: Derrick Stolee <dstolee@microsoft.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2019-06-19commit-graph: write commit-graph chainsLibravatar Derrick Stolee1-11/+275
Extend write_commit_graph() to write a commit-graph chain when given the COMMIT_GRAPH_SPLIT flag. This implementation is purposefully simplistic in how it creates a new chain. The commits not already in the chain are added to a new tip commit-graph file. Much of the logic around writing a graph-{hash}.graph file and updating the commit-graph-chain file is the same as the commit-graph file case. However, there are several places where we need to do some extra logic in the split case. Track the list of graph filenames before and after the planned write. This will be more important when we start merging graph files, but it also allows us to upgrade our commit-graph file to the appropriate graph-{hash}.graph file when we upgrade to a chain of commit-graphs. Note that we use the eighth byte of the commit-graph header to store the number of base graph files. This determines the length of the base graphs chunk. A subtle change of behavior with the new logic is that we do not write a commit-graph if we our commit list is empty. This extends to the typical case, which is reflected in t5318-commit-graph.sh. Signed-off-by: Derrick Stolee <dstolee@microsoft.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2019-06-19commit-graph: rearrange chunk count logicLibravatar Derrick Stolee1-14/+21
The number of chunks in a commit-graph file can change depending on whether we need the Extra Edges Chunk. We are going to add more optional chunks, and it will be helpful to rearrange this logic around the chunk count before doing so. Specifically, we need to finalize the number of chunks before writing the commit-graph header. Further, we also need to fill out the chunk lookup table dynamically and using "num_chunks" as we add optional chunks is useful for adding optional chunks in the future. Signed-off-by: Derrick Stolee <dstolee@microsoft.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2019-06-19commit-graph: add base graphs chunkLibravatar Derrick Stolee1-0/+22
To quickly verify a commit-graph chain is valid on load, we will read from the new "Base Graphs Chunk" of each file in the chain. This will prevent accidentally loading incorrect data from manually editing the commit-graph-chain file or renaming graph-{hash}.graph files. The commit_graph struct already had an object_id struct "oid", but it was never initialized or used. Add a line to read the hash from the end of the commit-graph file and into the oid member. Signed-off-by: Derrick Stolee <dstolee@microsoft.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2019-06-19commit-graph: load commit-graph chainsLibravatar Derrick Stolee1-6/+106
Prepare the logic for reading a chain of commit-graphs. First, look for a file at $OBJDIR/info/commit-graph. If it exists, then use that file and stop. Next, look for the chain file at $OBJDIR/info/commit-graphs/commit-graph-chain. If this file exists, then load the hash values as line-separated values in that file and load $OBJDIR/info/commit-graphs/graph-{hash[i]}.graph for each hash[i] in that file. The file is given in order, so the first hash corresponds to the "base" file and the final hash corresponds to the "tip" file. This implementation assumes that all of the graph-{hash}.graph files are in the same object directory as the commit-graph-chain file. This will be updated in a future change. This change is purposefully simple so we can isolate the different concerns. Signed-off-by: Derrick Stolee <dstolee@microsoft.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2019-06-19commit-graph: rename commit_compare to oid_compareLibravatar Derrick Stolee1-2/+2
The helper function commit_compare() actually compares object_id structs, not commits. A future change to commit-graph.c will need to sort commit structs, so rename this function in advance. Signed-off-by: Derrick Stolee <dstolee@microsoft.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2019-06-19commit-graph: prepare for commit-graph chainsLibravatar Derrick Stolee1-11/+78
To prepare for a chain of commit-graph files, augment the commit_graph struct to point to a base commit_graph. As we load commits from the graph, we may actually want to read from a base file according to the graph position. The "graph position" of a commit is given by concatenating the lexicographic commit orders from each of the commit-graph files in the chain. This means that we must distinguish two values: * lexicographic index : the position within the lexicographic order in a single commit-graph file. * graph position: the position within the concatenated order of multiple commit-graph files Given the lexicographic index of a commit in a graph, we can compute the graph position by adding the number of commits in the lower-level graphs. To find the lexicographic index of a commit, we subtract the number of commits in lower-level graphs. While here, change insert_parent_or_die() to take a uint32_t position, as that is the type used by its only caller and that makes more sense with the limits in the commit-graph format. Signed-off-by: Derrick Stolee <dstolee@microsoft.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2019-06-12commit-graph: use raw_object_store when closingLibravatar Derrick Stolee1-4/+4
The close_commit_graph() method took a repository struct, but then only uses the raw_object_store within. Change the function prototype to make the method more flexible. Signed-off-by: Derrick Stolee <dstolee@microsoft.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2019-06-12commit-graph: extract write_commit_graph_file()Libravatar Derrick Stolee1-75/+80
The write_commit_graph() method is too complex, so we are extracting helper functions one by one. Extract write_commit_graph_file() that takes all of the information in the context struct and writes the data to a commit-graph file. Signed-off-by: Derrick Stolee <dstolee@microsoft.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2019-06-12commit-graph: extract copy_oids_to_commits()Libravatar Derrick Stolee1-25/+32
The write_commit_graph() method is too complex, so we are extracting helper functions one by one. Extract copy_oids_to_commits(), which fills the commits list with the distinct commits from the oids list. During this loop, it also counts the number of "extra" edges from octopus merges. Signed-off-by: Derrick Stolee <dstolee@microsoft.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2019-06-12commit-graph: extract count_distinct_commits()Libravatar Derrick Stolee1-13/+22
The write_commit_graph() method is too complex, so we are extracting helper functions one by one. Extract count_distinct_commits(), which sorts the oids list, then iterates through to find duplicates. Signed-off-by: Derrick Stolee <dstolee@microsoft.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2019-06-12commit-graph: extract fill_oids_from_all_packs()Libravatar Derrick Stolee1-11/+15
The write_commit_graph() method is too complex, so we are extracting helper functions one by one. Extract fill_oids_from_all_packs() that reads all pack-files for commits and fills the oid list in the context. Signed-off-by: Derrick Stolee <dstolee@microsoft.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2019-06-12commit-graph: extract fill_oids_from_commit_hex()Libravatar Derrick Stolee1-32/+40
The write_commit_graph() method is too complex, so we are extracting helper functions one by one. Extract fill_oids_from_commit_hex() that reads the given commit id list and fille the oid list in the context. Signed-off-by: Derrick Stolee <dstolee@microsoft.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2019-06-12commit-graph: extract fill_oids_from_packs()Libravatar Derrick Stolee1-36/+47
The write_commit_graph() method is too complex, so we are extracting helper functions one by one. This extracts fill_oids_from_packs() that reads the given pack-file list and fills the oid list in the context. Signed-off-by: Derrick Stolee <dstolee@microsoft.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2019-06-12commit-graph: create write_commit_graph_contextLibravatar Derrick Stolee1-196/+194
The write_commit_graph() method is too large and complex. To simplify it, we should extract several helper functions. However, we will risk repeating a lot of declarations related to progress incidators and object id or commit lists. Create a new write_commit_graph_context struct that contains the core data structures used in this process. Replace the other local variables with the values inside the context object. Following this change, we will start to lift code segments wholesale out of the write_commit_graph() method and into helper functions. Signed-off-by: Derrick Stolee <dstolee@microsoft.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2019-06-12commit-graph: collapse parameters into flagsLibravatar Derrick Stolee1-4/+5
The write_commit_graph() and write_commit_graph_reachable() methods currently take two boolean parameters: 'append' and 'report_progress'. As we update these methods, adding more parameters this way becomes cluttered and hard to maintain. Collapse these parameters into a 'flags' parameter, and adjust the callers to provide flags as necessary. Signed-off-by: Derrick Stolee <dstolee@microsoft.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2019-06-12commit-graph: return with errors during writeLibravatar Derrick Stolee1-19/+41
The write_commit_graph() method uses die() to report failure and exit when confronted with an unexpected condition. This use of die() in a library function is incorrect and is now replaced by error() statements and an int return type. Return zero on success and a negative value on failure. Now that we use 'goto cleanup' to jump to the terminal condition on an error, we have new paths that could lead to uninitialized values. New initializers are added to correct for this. The builtins 'commit-graph', 'gc', and 'commit' call these methods, so update them to check the return value. Test that 'git commit-graph write' returns a proper error code when hitting a failure condition in write_commit_graph(). Signed-off-by: Derrick Stolee <dstolee@microsoft.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2019-05-19Merge branch 'js/commit-graph-parse-leakfix'Libravatar Junio C Hamano1-1/+3
Leakfix. * js/commit-graph-parse-leakfix: commit-graph: fix memory leak
2019-05-09Merge branch 'nd/sha1-name-c-wo-the-repository'Libravatar Junio C Hamano1-2/+7
Further code clean-up to allow the lowest level of name-to-object mapping layer to work with a passed-in repository other than the default one. * nd/sha1-name-c-wo-the-repository: (34 commits) sha1-name.c: remove the_repo from get_oid_mb() sha1-name.c: remove the_repo from other get_oid_* sha1-name.c: remove the_repo from maybe_die_on_misspelt_object_name submodule-config.c: use repo_get_oid for reading .gitmodules sha1-name.c: add repo_get_oid() sha1-name.c: remove the_repo from get_oid_with_context_1() sha1-name.c: remove the_repo from resolve_relative_path() sha1-name.c: remove the_repo from diagnose_invalid_index_path() sha1-name.c: remove the_repo from handle_one_ref() sha1-name.c: remove the_repo from get_oid_1() sha1-name.c: remove the_repo from get_oid_basic() sha1-name.c: remove the_repo from get_describe_name() sha1-name.c: remove the_repo from get_oid_oneline() sha1-name.c: add repo_interpret_branch_name() sha1-name.c: remove the_repo from interpret_branch_mark() sha1-name.c: remove the_repo from interpret_nth_prior_checkout() sha1-name.c: remove the_repo from get_short_oid() sha1-name.c: add repo_for_each_abbrev() sha1-name.c: store and use repo in struct disambiguate_state sha1-name.c: add repo_find_unique_abbrev_r() ...
2019-05-07commit-graph: fix memory leakLibravatar Josh Steadmon1-1/+3
Free the commit graph when verify_commit_graph_lite() reports an error. Credit to OSS-Fuzz for finding this leak. Signed-off-by: Josh Steadmon <steadmon@google.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2019-04-16commit.cocci: refactor code, avoid double rewriteLibravatar Nguyễn Thái Ngọc Duy1-2/+7
"maybe" pointer in 'struct commit' is tricky because it can be lazily initialized to take advantage of commit-graph if available. This makes it not safe to access directly. This leads to a rule in commit.cocci to rewrite 'x->maybe_tree' to 'get_commit_tree(x)'. But that rule alone could lead to incorrectly rewrite assignments, e.g. from x->maybe_tree = yes to get_commit_tree(x) = yes Because of this we have a second rule to revert this effect. Szeder found out that we could do better by performing the assignment rewrite rule first, then the remaining is read-only access and handled by the current first rule. For this to work, we need to transform "x->maybe_tree = y" to something that does NOT contain "x->maybe_tree" to avoid the original first rule. This is where set_commit_tree() comes in. Helped-by: SZEDER Gábor <szeder.dev@gmail.com> Helped-by: Johannes Schindelin <Johannes.Schindelin@gmx.de> Signed-off-by: Nguyễn Thái Ngọc Duy <pclouds@gmail.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2019-04-01commit-graph: improve & i18n error messagesLibravatar Ævar Arnfjörð Bjarmason1-19/+19
Change the error emitted when a commit-graph file is corrupt so that we actually mention the commit-graph, e.g. change errors like: error: improper chunk offset 0000000000385e0c To: error: commit-graph improper chunk offset 0000000000385e0c As discussed in the commits leading up to this one the commit-graph machinery is now used by common commands like "status". If the graph was corrupt we'd often emit some error that gave no indication what was wrong. Now some of them are still cryptic, but they'll at least mention "commit-graph" to give the user a hint as to where to look. While I'm at it mark some of the strings that hadn't been marked for translation. It's clear from the commit history and the code that this was merely forgotten at the time, and wasn't intentional.p5 Signed-off-by: Ævar Arnfjörð Bjarmason <avarab@gmail.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2019-04-01commit-graph write: don't die if the existing graph is corruptLibravatar Ævar Arnfjörð Bjarmason1-3/+7
When the commit-graph is written we end up calling parse_commit(). This will in turn invoke code that'll consult the existing commit-graph about the commit, if the graph is corrupted we die. We thus get into a state where a failing "commit-graph verify" can't be followed-up with a "commit-graph write" if core.commitGraph=true is set, the graph either needs to be manually removed to proceed, or core.commitGraph needs to be set to "false". Change the "commit-graph write" codepath to use a new parse_commit_no_graph() helper instead of parse_commit() to avoid this. The latter will call repo_parse_commit_internal() with use_commit_graph=1 as seen in 177722b344 ("commit: integrate commit graph with commit parsing", 2018-04-10). Not using the old graph at all slows down the writing of the new graph by some small amount, but is a sensible way to prevent an error in the existing commit-graph from spreading. Just fixing the current issue would be likely to result in code that's inadvertently broken in the future. New code might use the commit-graph at a distance. To detect such cases introduce a "GIT_TEST_COMMIT_GRAPH_DIE_ON_LOAD" setting used when we do our corruption tests, and test that a "write/verify" combo works after every one of our current test cases where we now detect commit-graph corruption. Some of the code changes here might be strictly unnecessary, e.g. I was unable to find cases where the parse_commit() called from write_graph_chunk_data() didn't exit early due to "item->object.parsed" being true in repo_parse_commit_internal() (before the use_commit_graph=1 has any effect). But let's also convert those cases for good measure, we do not have exhaustive tests for all possible types of commit-graph corruption. This might need to be re-visited if we learn to write the commit-graph incrementally, but probably not. Hopefully we'll just start by finding out what commits we have in total, then read the old graph(s) to see what they cover, and finally write a new graph file with everything that's missing. In that case the new graph writing code just needs to continue to use e.g. a parse_commit() that doesn't consult the existing commit-graphs. Signed-off-by: Ævar Arnfjörð Bjarmason <avarab@gmail.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2019-04-01commit-graph: don't pass filename to load_commit_graph_one_fd_st()Libravatar Ævar Arnfjörð Bjarmason1-4/+3
An earlier change implemented load_commit_graph_one_fd_st() in a way that was bug-compatible with earlier code in terms of the "graph file %s is too small" error message printing out the path to the commit-graph (".git/objects/info/commit-graph"). But change that, because: * A function that takes an already-open file descriptor also needing the filename isn't very intuitive. * The vast majority of errors we might emit when loading the graph come from parse_commit_graph(), which doesn't report the filename. Let's not do that either in this case for consistency. Signed-off-by: Ævar Arnfjörð Bjarmason <avarab@gmail.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2019-04-01commit-graph: don't early exit(1) on e.g. "git status"Libravatar Ævar Arnfjörð Bjarmason1-12/+30
Make the commit-graph loading code work as a library that returns an error code instead of calling exit(1) when the commit-graph is corrupt. This means that e.g. "status" will now report commit-graph corruption as an "error: [...]" at the top of its output, but then proceed to work normally. This required splitting up the load_commit_graph_one() function so that the code that deals with open()-ing and stat()-ing the graph can now be called independently as open_commit_graph(). This is needed because "commit-graph verify" where the graph doesn't exist isn't an error. See the third paragraph in 283e68c72f ("commit-graph: add 'verify' subcommand", 2018-06-27). There's a bug in that logic where we conflate the intended ENOENT with other errno values (e.g. EACCES), but this change doesn't address that. That'll be addressed in a follow-up change. I'm then splitting most of the logic out of load_commit_graph_one() into load_commit_graph_one_fd_st(), which allows for providing an existing file descriptor and stat information to the loading code. This isn't strictly needed, but it would be redundant and confusing to open() and stat() the file twice for some of the codepaths, this allows for calling open_commit_graph() followed by load_commit_graph_one_fd_st(). The "graph_file" still needs to be passed to that function for the the "graph file %s is too small" error message. This leaves load_commit_graph_one() unused by everything except the internal prepare_commit_graph_one() function, so let's mark it as "static". If someone needs it in the future we can remove the "static" attribute. I could also rewrite its sole remaining user ("prepare_commit_graph_one()") to use load_commit_graph_one_fd_st() instead, but let's leave it at this. Signed-off-by: Ævar Arnfjörð Bjarmason <avarab@gmail.com> Signed-off-by: Ramsay Jones <ramsay@ramsayjones.plus.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2019-04-01commit-graph: fix segfault on e.g. "git status"Libravatar Ævar Arnfjörð Bjarmason1-9/+34
When core.commitGraph=true is set, various common commands now consult the commit graph. Because the commit-graph code is very trusting of its input data, it's possibly to construct a graph that'll cause an immediate segfault on e.g. "status" (and e.g. "log", "blame", ...). In some other cases where git immediately exits with a cryptic error about the graph being broken. The root cause of this is that while the "commit-graph verify" sub-command exhaustively verifies the graph, other users of the graph simply trust the graph, and will e.g. deference data found at certain offsets as pointers, causing segfaults. This change does the bare minimum to ensure that we don't segfault in the common fill_commit_in_graph() codepath called by e.g. setup_revisions(), to do this instrument the "commit-graph verify" tests to always check if "status" would subsequently segfault. This fixes the following tests which would previously segfault: not ok 50 - detect low chunk count not ok 51 - detect missing OID fanout chunk not ok 52 - detect missing OID lookup chunk not ok 53 - detect missing commit data chunk Those happened because with the commit-graph enabled setup_revisions() would eventually call fill_commit_in_graph(), where e.g. g->chunk_commit_data is used early as an offset (and will be 0x0). With this change we get far enough to detect that the graph is broken, and show an error instead. E.g.: $ git status; echo $? error: commit-graph is missing the Commit Data chunk 1 That also sucks, we should *warn* and not hard-fail "status" just because the commit-graph is corrupt, but fixing is left to a follow-up change. A side-effect of changing the reporting from graph_report() to error() is that we now have an "error: " prefix for these even for "commit-graph verify". Pseudo-diff before/after: $ git commit-graph verify -commit-graph is missing the Commit Data chunk +error: commit-graph is missing the Commit Data chunk Changing that is OK. Various errors it emits now early on are prefixed with "error: ", moving these over and changing the output doesn't break anything. Signed-off-by: Ævar Arnfjörð Bjarmason <avarab@gmail.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2019-02-05Merge branch 'ab/commit-graph-write-progress'Libravatar Junio C Hamano1-36/+94
The codepath to show progress meter while writing out commit-graph file has been improved. * ab/commit-graph-write-progress: commit-graph write: emit a percentage for all progress commit-graph write: add itermediate progress commit-graph write: remove empty line for readability commit-graph write: add more descriptive progress output commit-graph write: show progress for object search commit-graph write: more descriptive "writing out" output commit-graph write: add "Writing out" progress output commit-graph: don't call write_graph_chunk_extra_edges() unnecessarily commit-graph: rename "large edges" to "extra edges"
2019-02-05Merge branch 'ab/commit-graph-write-optim'Libravatar Junio C Hamano1-2/+4
The codepath to write out commit-graph has been optimized by following the usual pattern of visiting objects in in-pack order. * ab/commit-graph-write-optim: commit-graph write: use pack order when finding commits
2019-02-05Merge branch 'js/commit-graph-chunk-table-fix'Libravatar Junio C Hamano1-19/+48
The codepath to read from the commit-graph file attempted to read past the end of it when the file's table-of-contents was corrupt. * js/commit-graph-chunk-table-fix: Makefile: correct example fuzz build commit-graph: fix buffer read-overflow commit-graph, fuzz: add fuzzer for commit-graph
2019-02-05Merge branch 'sb/more-repo-in-api'Libravatar Junio C Hamano1-16/+24
The in-core repository instances are passed through more codepaths. * sb/more-repo-in-api: (23 commits) t/helper/test-repository: celebrate independence from the_repository path.h: make REPO_GIT_PATH_FUNC repository agnostic commit: prepare free_commit_buffer and release_commit_memory for any repo commit-graph: convert remaining functions to handle any repo submodule: don't add submodule as odb for push submodule: use submodule repos for object lookup pretty: prepare format_commit_message to handle arbitrary repositories commit: prepare logmsg_reencode to handle arbitrary repositories commit: prepare repo_unuse_commit_buffer to handle any repo commit: prepare get_commit_buffer to handle any repo commit-reach: prepare in_merge_bases[_many] to handle any repo commit-reach: prepare get_merge_bases to handle any repo commit-reach.c: allow get_merge_bases_many_0 to handle any repo commit-reach.c: allow remove_redundant to handle any repo commit-reach.c: allow merge_bases_many to handle any repo commit-reach.c: allow paint_down_to_common to handle any repo commit: allow parse_commit* to handle any repo object: parse_object to honor its repository argument object-store: prepare has_{sha1, object}_file to handle any repo object-store: prepare read_object_file to deal with any repo ...
2019-01-29Merge branch 'bc/sha-256'Libravatar Junio C Hamano1-16/+17
Add sha-256 hash and plug it through the code to allow building Git with the "NewHash". * bc/sha-256: hash: add an SHA-256 implementation using OpenSSL sha256: add an SHA-256 implementation using libgcrypt Add a base implementation of SHA-256 support commit-graph: convert to using the_hash_algo t/helper: add a test helper to compute hash speed sha1-file: add a constant for hash block size t: make the sha1 test-tool helper generic t: add basic tests for our SHA-1 implementation cache: make hashcmp and hasheq work with larger hashes hex: introduce functions to print arbitrary hashes sha1-file: provide functions to look up hash algorithms sha1-file: rename algorithm to "sha1"
2019-01-23commit-graph write: emit a percentage for all progressLibravatar Ævar Arnfjörð Bjarmason1-7/+7
Follow-up 01ca387774 ("commit-graph: split up close_reachable() progress output", 2018-11-19) by making the progress bars in close_reachable() report a completion percentage. This fixes the last occurrence where in the commit graph writing where we didn't report that. The change in 01ca387774 split up the 1x progress bar in close_reachable() into 3x, but left them as dumb counters without a percentage completion. Fixing that is easy, and the only reason it wasn't done already is because that commit was rushed in during the v2.20.0 RC period to fix the unrelated issue of over-reporting commit numbers. See [1] and follow-ups for ML activity at the time and [2] for an alternative approach where the progress bars weren't split up. Now for e.g. linux.git we'll emit: $ ~/g/git/git --exec-path=$HOME/g/git commit-graph write Finding commits for commit graph among packed objects: 100% (6529159/6529159), done. Expanding reachable commits in commit graph: 100% (815990/815980), done. Computing commit graph generation numbers: 100% (815983/815983), done. Writing out commit graph in 4 passes: 100% (3263932/3263932), done. 1. https://public-inbox.org/git/20181119202300.18670-1-avarab@gmail.com/ 2. https://public-inbox.org/git/20181122153922.16912-11-avarab@gmail.com/ Signed-off-by: Ævar Arnfjörð Bjarmason <avarab@gmail.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2019-01-23commit-graph write: add itermediate progressLibravatar Ævar Arnfjörð Bjarmason1-0/+13
Add progress output to sections of code between "Annotating[...]" and "Computing[...]generation numbers". This can collectively take 5-10 seconds on a large enough repository. On a test repository with I have with ~7 million commits and ~50 million objects we'll now emit: $ ~/g/git/git --exec-path=$HOME/g/git commit-graph write Finding commits for commit graph among packed objects: 100% (124763727/124763727), done. Loading known commits in commit graph: 100% (18989461/18989461), done. Expanding reachable commits in commit graph: 100% (18989507/18989461), done. Clearing commit marks in commit graph: 100% (18989507/18989507), done. Counting distinct commits in commit graph: 100% (18989507/18989507), done. Finding extra edges in commit graph: 100% (18989507/18989507), done. Computing commit graph generation numbers: 100% (7250302/7250302), done. Writing out commit graph in 4 passes: 100% (29001208/29001208), done. Whereas on a medium-sized repository such as linux.git these new progress bars won't have time to kick in and as before and we'll still emit output like: $ ~/g/git/git --exec-path=$HOME/g/git commit-graph write Finding commits for commit graph among packed objects: 100% (6529159/6529159), done. Expanding reachable commits in commit graph: 815990, done. Computing commit graph generation numbers: 100% (815983/815983), done. Writing out commit graph in 4 passes: 100% (3263932/3263932), done. The "Counting distinct commits in commit graph" phase will spend most of its time paused at "0/*" as we QSORT(...) the list. That's not optimal, but at least we don't seem to be stalling anymore most of the time. Signed-off-by: Ævar Arnfjörð Bjarmason <avarab@gmail.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2019-01-23commit-graph write: remove empty line for readabilityLibravatar Ævar Arnfjörð Bjarmason1-1/+0
Remove the empty line between a QSORT(...) and the subsequent oideq() for-loop. This makes it clearer that the QSORT(...) is being done so that we can run the oideq() loop on adjacent OIDs. Amends code added in 08fd81c9b6 ("commit-graph: implement write_commit_graph()", 2018-04-02). Signed-off-by: Ævar Arnfjörð Bjarmason <avarab@gmail.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2019-01-23commit-graph write: add more descriptive progress outputLibravatar Ævar Arnfjörð Bjarmason1-7/+18
Make the progress output shown when we're searching for commits to include in the graph more descriptive. This amends code I added in 7b0f229222 ("commit-graph write: add progress output", 2018-09-17). Now, on linux.git, we'll emit this sort of output in the various modes we support: $ git commit-graph write Finding commits for commit graph among packed objects: 100% (6529159/6529159), done. [...] # Actually we don't emit this since this takes almost no time at # all. But if we did (s/_delayed//) we'd show: $ git for-each-ref --format='%(objectname)' | git commit-graph write --stdin-commits Finding commits for commit graph from 630 refs: 100% (630/630), done. [...] $ (cd .git/objects/pack/ && ls *idx) | git commit-graph write --stdin-pack Finding commits for commit graph in 3 packs: 6529159, done. [...] The middle on of those is going to be the output users might see in practice, since it'll be emitted when they get the commit graph via gc.writeCommitGraph=true. But as noted above you need a really large number of refs for this message to show. It'll show up on a test repository I have with ~165k refs: Finding commits for commit graph from 165203 refs: 100% (165203/165203), done. Signed-off-by: Ævar Arnfjörð Bjarmason <avarab@gmail.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>