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2015-03-20refs.c: drop curate_packed_refsJeff King
When we delete a ref, we have to rewrite the entire packed-refs file. We take this opportunity to "curate" the packed-refs file and drop any entries that are crufty or broken. Dropping broken entries (e.g., with bogus names, or ones that point to missing objects) is actively a bad idea, as it means that we lose any notion that the data was there in the first place. Aside from the general hackiness that we might lose any information about ref "foo" while deleting an unrelated ref "bar", this may seriously hamper any attempts by the user at recovering from the corruption in "foo". They will lose the sha1 and name of "foo"; the exact pointer may still be useful even if they recover missing objects from a different copy of the repository. But worse, once the ref is gone, there is no trace of the corruption. A follow-up "git prune" may delete objects, even though it would otherwise bail when seeing corruption. We could just drop the "broken" bits from curate_packed_refs, and continue to drop the "crufty" bits: refs whose loose counterpart exists in the filesystem. This is not wrong to do, and it does have the advantage that we may write out a slightly smaller packed-refs file. But it has two disadvantages: 1. It is a potential source of races or mistakes with respect to these refs that are otherwise unrelated to the operation. To my knowledge, there aren't any active problems in this area, but it seems like an unnecessary risk. 2. We have to spend time looking up the matching loose refs for every item in the packed-refs file. If you have a large number of packed refs that do not change, that outweighs the benefit from writing out a smaller packed-refs file (it doesn't get smaller, and you do a bunch of directory traversal to find that out). Signed-off-by: Jeff King <peff@peff.net> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2015-03-20refs: introduce a "ref paranoia" flagJeff King
Most operations that iterate over refs are happy to ignore broken cruft. However, some operations should be performed with knowledge of these broken refs, because it is better for the operation to choke on a missing object than it is to silently pretend that the ref did not exist (e.g., if we are computing the set of reachable tips in order to prune objects). These processes could just call for_each_rawref, except that ref iteration is often hidden behind other interfaces. For instance, for a destructive "repack -ad", we would have to inform "pack-objects" that we are destructive, and then it would in turn have to tell the revision code that our "--all" should include broken refs. It's much simpler to just set a global for "dangerous" operations that includes broken refs in all iterations. Signed-off-by: Jeff King <peff@peff.net> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2015-02-25Merge branch 'jk/blame-commit-label' into maintJunio C Hamano
"git blame HEAD -- missing" failed to correctly say "HEAD" when it tried to say "No such path 'missing' in HEAD". * jk/blame-commit-label: blame.c: fix garbled error message use xstrdup_or_null to replace ternary conditionals builtin/commit.c: use xstrdup_or_null instead of envdup builtin/apply.c: use xstrdup_or_null instead of null_strdup git-compat-util: add xstrdup_or_null helper
2015-01-13use xstrdup_or_null to replace ternary conditionalsJeff King
This replaces "x ? xstrdup(x) : NULL" with xstrdup_or_null(x). The change is fairly mechanical, with the exception of resolve_refdup, which can eliminate a temporary variable. There are still a few hits grepping for "?.*xstrdup", but these are of slightly different forms and cannot be converted (e.g., "x ? xstrdup(x->foo) : NULL"). Signed-off-by: Jeff King <peff@peff.net> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2014-12-29refs: plug strbuf leak in lock_ref_sha1_basic()René Scharfe
Don't just reset, but release the resource held by the local variable that is about to go out of scope. Signed-off-by: Rene Scharfe <l.s.r@web.de> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2014-12-22Merge branch 'jk/read-packed-refs-without-path-max'Junio C Hamano
Git did not correctly read an overlong refname from a packed refs file. * jk/read-packed-refs-without-path-max: read_packed_refs: use skip_prefix instead of static array read_packed_refs: pass strbuf to parse_ref_line read_packed_refs: use a strbuf for reading lines
2014-12-22Merge branch 'jk/for-each-reflog-ent-reverse'Junio C Hamano
The code that reads the reflog from the newer to the older entries did not handle an entry that crosses a boundary of block it uses to read them correctly. * jk/for-each-reflog-ent-reverse: for_each_reflog_ent_reverse: turn leftover check into assertion for_each_reflog_ent_reverse: fix newlines on block boundaries
2014-12-22Merge branch 'mh/simplify-repack-without-refs'Junio C Hamano
"git remote update --prune" to drop many refs has been optimized. * mh/simplify-repack-without-refs: sort_string_list(): rename to string_list_sort() prune_remote(): iterate using for_each_string_list_item() prune_remote(): rename local variable repack_without_refs(): make the refnames argument a string_list prune_remote(): sort delete_refs_list references en masse prune_remote(): initialize both delete_refs lists in a single loop prune_remote(): exit early if there are no stale references
2014-12-10read_packed_refs: use skip_prefix instead of static arrayJeff King
We want to recognize the packed-refs header and skip to the "traits" part of the line. We currently do it by feeding sizeof() a static const array to strncmp. However, it's a bit simpler to just skip_prefix, which expresses the intention more directly, and without remembering to account for the NUL-terminator in each sizeof() call. Signed-off-by: Jeff King <peff@peff.net> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2014-12-10read_packed_refs: pass strbuf to parse_ref_lineJeff King
Now that we have a strbuf in read_packed_refs, we can pass it straight to the line parser, which saves us an extra strlen. Signed-off-by: Jeff King <peff@peff.net> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2014-12-10read_packed_refs: use a strbuf for reading linesJeff King
Current code uses a fixed PATH_MAX-sized buffer for reading packed-refs lines. This is a reasonable guess, in the sense that git generally cannot work with refs larger than PATH_MAX. However, there are a few cases where it is not great: 1. Some systems may have a low value of PATH_MAX, but can actually handle larger paths in practice. Fixing this code path probably isn't enough to make them work completely with long refs, but it is a step in the right direction. 2. We use fgets, which will happily give us half a line on the first read, and then the rest of the line on the second. This is probably OK in practice, because our refline parser is careful enough to look for the trailing newline on the first line. The second line may look like a peeled line to us, but since "^" is illegal in refnames, it is not likely to come up. Still, it does not hurt to be more careful. Signed-off-by: Jeff King <peff@peff.net> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2014-12-05for_each_reflog_ent_reverse: turn leftover check into assertionJeff King
Our loop should always process all lines, even if we hit the beginning of the file. We have a conditional after the loop ends to double-check that there is nothing left and to process it. But this should never happen, and is a sign of a logic bug in the loop. Let's turn it into a BUG assertion. Signed-off-by: Jeff King <peff@peff.net> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2014-12-05for_each_reflog_ent_reverse: fix newlines on block boundariesJeff King
When we read a reflog file in reverse, we read whole chunks of BUFSIZ bytes, then loop over the buffer, parsing any lines we find. We find the beginning of each line by looking for the newline from the previous line. If we don't find one, we know that we are either at the beginning of the file, or that we have to read another block. In the latter case, we stuff away what we have into a strbuf, read another block, and continue our parse. But we missed one case here. If we did find a newline, and it is at the beginning of the block, we must also stuff that newline into the strbuf, as it belongs to the block we are about to read. The minimal fix here would be to add this special case to the conditional that checks whether we found a newline. But we can make the flow a little clearer by rearranging a bit: we first handle lines that we are going to show, and then at the end of each loop, stuff away any leftovers if necessary. That lets us fold this special-case in with the more common "we ended in the middle of a line" case. Signed-off-by: Jeff King <peff@peff.net> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2014-11-25repack_without_refs(): make the refnames argument a string_listMichael Haggerty
Most of the callers have string_lists available already, whereas two of them had to read data out of a string_list into an array of strings just to call this function. So change repack_without_refs() to take the list of refnames to omit as a string_list, and change the callers accordingly. Suggested-by: Ronnie Sahlberg <sahlberg@google.com> Signed-off-by: Michael Haggerty <mhagger@alum.mit.edu> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2014-11-20lock_ref_sha1_basic: do not die on locking errorsRonnie Sahlberg
lock_ref_sha1_basic is inconsistent about when it calls die() and when it returns NULL to signal an error. This is annoying to any callers that want to recover from a locking error. This seems to be mostly historical accident. It was added in 4bd18c4 (Improve abstraction of ref lock/write., 2006-05-17), which returned an error in all cases except calling safe_create_leading_directories, in which case it died. Later, 40aaae8 (Better error message when we are unable to lock the index file, 2006-08-12) asked hold_lock_file_for_update to die for us, leaving the resolve_ref code-path the only one which returned NULL. We tried to correct that in 5cc3cef (lock_ref_sha1(): do not sometimes error() and sometimes die()., 2006-09-30), by converting all of the die() calls into returns. But we missed the "die" flag passed to the lock code, leaving us inconsistent. This state persisted until e5c223e (lock_ref_sha1_basic(): if locking fails with ENOENT, retry, 2014-01-18). Because of its retry scheme, it does not ask the lock code to die, but instead manually dies with unable_to_lock_die(). We can make this consistent with the other return paths by converting this to use unable_to_lock_message(), and returning NULL. This is safe to do because all callers already needed to check the return value of the function, since it could fail (and return NULL) for other reasons. [jk: Added excessive history explanation] Signed-off-by: Ronnie Sahlberg <sahlberg@google.com> Signed-off-by: Jeff King <peff@peff.net> Reviewed-by: Jonathan Nieder <jrnieder@gmail.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2014-11-06Merge branch 'jk/fetch-reflog-df-conflict'Junio C Hamano
Corner-case bugfixes for "git fetch" around reflog handling. * jk/fetch-reflog-df-conflict: ignore stale directories when checking reflog existence fetch: load all default config at startup
2014-11-04ignore stale directories when checking reflog existenceJeff King
When we update a ref, we have two rules for whether or not we actually update the reflog: 1. If the reflog already exists, we will always append to it. 2. If log_all_ref_updates is set, we will create a new reflog file if necessary. We do the existence check by trying to open the reflog file, either with or without O_CREAT (depending on log_all_ref_updates). If it fails, then we check errno to see what happened. If we were not using O_CREAT and we got ENOENT, the file doesn't exist, and we return success (there isn't a reflog already, and we were not told to make a new one). If we get EISDIR, then there is likely a stale directory that needs to be removed (e.g., there used to be "foo/bar", it was deleted, and the directory "foo" was left. Now we want to create the ref "foo"). If O_CREAT is set, then we catch this case, try to remove the directory, and retry our open. So far so good. But if we get EISDIR and O_CREAT is not set, then we treat this as any other error, which is not right. Like ENOENT, EISDIR is an indication that we do not have a reflog, and we should silently return success (we were not told to create it). Instead, the current code reports this as an error, and we fail to update the ref at all. Note that this is relatively unlikely to happen, as you would have to have had reflogs turned on, and then later turned them off (it could also happen due to a bug in fetch, but that was fixed in the previous commit). However, it's quite easy to fix: we just need to treat EISDIR like ENOENT for the non-O_CREAT case, and silently return (note that this early return means we can also simplify the O_CREAT case). Our new tests cover both cases (O_CREAT and non-O_CREAT). The first one already worked, of course. Signed-off-by: Jeff King <peff@peff.net> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2014-10-15ref_transaction_commit: bail out on failure to remove a refJonathan Nieder
When removal of a loose or packed ref fails, bail out instead of trying to finish the transaction. This way, a single error message can be printed (instead of multiple messages being concatenated by mistake) and the operator can try to solve the underlying problem before there is a chance to muck things up even more. In particular, when git fails to remove a ref, git goes on to try to delete the reflog. Exiting early lets us keep the reflog. When git succeeds in deleting a ref A and fails to remove a ref B, it goes on to try to delete both reflogs. It would be better to just remove the reflog for A, but that would be a more invasive change. Failing early means we keep both reflogs, which puts the operator in a good position to understand the problem and recover. A long term goal is to avoid these problems altogether and roll back the transaction on failure. That kind of transactionality will have to wait for a later series (the plan for which is to make all destructive work happen in a single update of the packed-refs file). Signed-off-by: Jonathan Nieder <jrnieder@gmail.com> Reviewed-by: Ronnie Sahlberg <sahlberg@google.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2014-10-15refs.c: do not permit err == NULLJonathan Nieder
Some functions that take a strbuf argument to append an error treat !err as an indication that the message should be suppressed (e.g., ref_update_reject_duplicates). Others write the message to stderr on !err (e.g., repack_without_refs). Others crash (e.g., ref_transaction_update). Some of these behaviors are for historical reasons and others were accidents. Luckily no callers pass err == NULL any more. Simplify by consistently requiring the strbuf argument. Signed-off-by: Jonathan Nieder <jrnieder@gmail.com> Reviewed-by: Ronnie Sahlberg <sahlberg@google.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2014-10-15refs.c: allow listing and deleting badly named refsRonnie Sahlberg
We currently do not handle badly named refs well: $ cp .git/refs/heads/master .git/refs/heads/master.....@\*@\\. $ git branch fatal: Reference has invalid format: 'refs/heads/master.....@*@\.' $ git branch -D master.....@\*@\\. error: branch 'master.....@*@\.' not found. Users cannot recover from a badly named ref without manually finding and deleting the loose ref file or appropriate line in packed-refs. Making that easier will make it easier to tweak the ref naming rules in the future, for example to forbid shell metacharacters like '`' and '"', without putting people in a state that is hard to get out of. So allow "branch --list" to show these refs and allow "branch -d/-D" and "update-ref -d" to delete them. Other commands (for example to rename refs) will continue to not handle these refs but can be changed in later patches. Details: In resolving functions, refuse to resolve refs that don't pass the git-check-ref-format(1) check unless the new RESOLVE_REF_ALLOW_BAD_NAME flag is passed. Even with RESOLVE_REF_ALLOW_BAD_NAME, refuse to resolve refs that escape the refs/ directory and do not match the pattern [A-Z_]* (think "HEAD" and "MERGE_HEAD"). In locking functions, refuse to act on badly named refs unless they are being deleted and either are in the refs/ directory or match [A-Z_]*. Just like other invalid refs, flag resolved, badly named refs with the REF_ISBROKEN flag, treat them as resolving to null_sha1, and skip them in all iteration functions except for for_each_rawref. Flag badly named refs (but not symrefs pointing to badly named refs) with a REF_BAD_NAME flag to make it easier for future callers to notice and handle them specially. For example, in a later patch for-each-ref will use this flag to detect refs whose names can confuse callers parsing for-each-ref output. In the transaction API, refuse to create or update badly named refs, but allow deleting them (unless they try to escape refs/ and don't match [A-Z_]*). Signed-off-by: Ronnie Sahlberg <sahlberg@google.com> Signed-off-by: Jonathan Nieder <jrnieder@gmail.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2014-10-15packed-ref cache: forbid dot-components in refnamesJonathan Nieder
Since v1.7.9-rc1~10^2 (write_head_info(): handle "extra refs" locally, 2012-01-06), this trick to keep track of ".have" refs that are only valid on the wire and not on the filesystem is not needed any more. Simplify by removing support for the REFNAME_DOT_COMPONENT flag. This means we'll be slightly stricter with invalid refs found in a packed-refs file or during clone. read_loose_refs() already checks for and skips refnames with .components so it is not affected. Signed-off-by: Jonathan Nieder <jrnieder@gmail.com> Reviewed-by: Ronnie Sahlberg <sahlberg@google.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2014-10-15branch -d: avoid repeated symref resolutionJonathan Nieder
If a repository gets in a broken state with too much symref nesting, it cannot be repaired with "git branch -d": $ git symbolic-ref refs/heads/nonsense refs/heads/nonsense $ git branch -d nonsense error: branch 'nonsense' not found. Worse, "git update-ref --no-deref -d" doesn't work for such repairs either: $ git update-ref -d refs/heads/nonsense error: unable to resolve reference refs/heads/nonsense: Too many levels of symbolic links Fix both by teaching resolve_ref_unsafe a new RESOLVE_REF_NO_RECURSE flag and passing it when appropriate. Callers can still read the value of a symref (for example to print a message about it) with that flag set --- resolve_ref_unsafe will resolve one level of symrefs and stop there. Signed-off-by: Jonathan Nieder <jrnieder@gmail.com> Reviewed-by: Ronnie Sahlberg <sahlberg@google.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2014-10-15refs.c: change resolve_ref_unsafe reading argument to be a flags fieldRonnie Sahlberg
resolve_ref_unsafe takes a boolean argument for reading (a nonexistent ref resolves successfully for writing but not for reading). Change this to be a flags field instead, and pass the new constant RESOLVE_REF_READING when we want this behaviour. While at it, swap two of the arguments in the function to put output arguments at the end. As a nice side effect, this ensures that we can catch callers that were unaware of the new API so they can be audited. Give the wrapper functions resolve_refdup and read_ref_full the same treatment for consistency. Signed-off-by: Ronnie Sahlberg <sahlberg@google.com> Signed-off-by: Jonathan Nieder <jrnieder@gmail.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2014-10-15refs.c: make write_ref_sha1 staticRonnie Sahlberg
No external users call write_ref_sha1 any more so let's declare it static. Signed-off-by: Ronnie Sahlberg <sahlberg@google.com> Signed-off-by: Jonathan Nieder <jrnieder@gmail.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2014-10-15refs.c: ref_transaction_commit: distinguish name conflicts from other errorsRonnie Sahlberg
In _commit, ENOTDIR can happen in the call to lock_ref_sha1_basic, either when we lstat the new refname or if the name checking function reports that the same type of conflict happened. In both cases, it means that we can not create the new ref due to a name conflict. Start defining specific return codes for _commit. TRANSACTION_NAME_CONFLICT refers to a failure to create a ref due to a name conflict with another ref. TRANSACTION_GENERIC_ERROR is for all other errors. When "git fetch" is creating refs, name conflicts differ from other errors in that they are likely to be resolved by running "git remote prune <remote>". "git fetch" currently inspects errno to decide whether to give that advice. Once it switches to the transaction API, it can check for TRANSACTION_NAME_CONFLICT instead. Signed-off-by: Ronnie Sahlberg <sahlberg@google.com> Signed-off-by: Jonathan Nieder <jrnieder@gmail.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2014-10-15refs.c: pass a list of names to skip to is_refname_availableRonnie Sahlberg
Change is_refname_available to take a list of strings to exclude when checking for conflicts instead of just one single name. We can already exclude a single name for the sake of renames. This generalizes that support. ref_transaction_commit already tracks a set of refs that are being deleted in an array. This array is then used to exclude refs from being written to the packed-refs file. At some stage we will want to change this array to a struct string_list and then we can pass it to is_refname_available via the call to lock_ref_sha1_basic. That will allow us to perform transactions that perform multiple renames as long as there are no conflicts within the starting or ending state. For example, that would allow a single transaction that contains two renames that are both individually conflicting: m -> n/n n -> m/m No functional change intended yet. Signed-off-by: Ronnie Sahlberg <sahlberg@google.com> Signed-off-by: Jonathan Nieder <jrnieder@gmail.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2014-10-15refs.c: call lock_ref_sha1_basic directly from commitRonnie Sahlberg
Skip using the lock_any_ref_for_update wrapper and call lock_ref_sha1_basic directly from the commit function. Signed-off-by: Ronnie Sahlberg <sahlberg@google.com> Reviewed-by: Michael Haggerty <mhagger@alum.mit.edu> Signed-off-by: Jonathan Nieder <jrnieder@gmail.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2014-10-15refs.c: refuse to lock badly named refs in lock_ref_sha1_basicRonnie Sahlberg
Move the check for check_refname_format from lock_any_ref_for_update to lock_ref_sha1_basic. At some later stage we will get rid of lock_any_ref_for_update completely. This has no visible impact to callers except for the inability to lock badly named refs, which is not possible today already for other reasons.(*) Keep lock_any_ref_for_update as a no-op wrapper. It is the public facing version of this interface and keeping it as a separate function will make it easier to experiment with the internal lock_ref_sha1_basic signature. (*) For example, if lock_ref_sha1_basic checks the refname format and refuses to lock badly named refs, it will not be possible to delete such refs because the first step of deletion is to lock the ref. We currently already fail in that case because these refs are not recognized to exist: $ cp .git/refs/heads/master .git/refs/heads/echo...\*\* $ git branch -D .git/refs/heads/echo...\*\* error: branch '.git/refs/heads/echo...**' not found. This has been broken for a while. Later patches in the series will start repairing the handling of badly named refs. Signed-off-by: Ronnie Sahlberg <sahlberg@google.com> Reviewed-by: Michael Haggerty <mhagger@alum.mit.edu> Signed-off-by: Jonathan Nieder <jrnieder@gmail.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2014-10-15rename_ref: don't ask read_ref_full where the ref came fromRonnie Sahlberg
We call read_ref_full with a pointer to flags from rename_ref but since we never actually use the returned flags we can just pass NULL here instead. Signed-off-by: Ronnie Sahlberg <sahlberg@google.com> Reviewed-by: Michael Haggerty <mhagger@alum.mit.edu> Signed-off-by: Jonathan Nieder <jrnieder@gmail.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2014-10-15refs.c: pass the ref log message to _create/delete/update instead of _commitRonnie Sahlberg
Change the ref transaction API so that we pass the reflog message to the create/delete/update functions instead of to ref_transaction_commit. This allows different reflog messages for each ref update in a multi-ref transaction. Signed-off-by: Ronnie Sahlberg <sahlberg@google.com> Signed-off-by: Jonathan Nieder <jrnieder@gmail.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2014-10-15refs.c: add an err argument to delete_ref_looseRonnie Sahlberg
Add an err argument to delete_ref_loose so that we can pass a descriptive error string back to the caller. Pass the err argument from transaction commit to this function so that transaction users will have a nice error string if the transaction failed due to delete_ref_loose. Signed-off-by: Ronnie Sahlberg <sahlberg@google.com> Signed-off-by: Jonathan Nieder <jrnieder@gmail.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2014-10-15refs.c: lock_ref_sha1_basic is used for all refsRonnie Sahlberg
lock_ref_sha1_basic is used to lock refs that sit directly in the .git dir such as HEAD and MERGE_HEAD in addition to the more ordinary refs under "refs/". Remove the note claiming otherwise. Signed-off-by: Ronnie Sahlberg <sahlberg@google.com> Signed-off-by: Jonathan Nieder <jrnieder@gmail.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2014-10-15wrapper.c: remove/unlink_or_warn: simplify, treat ENOENT as successRonnie Sahlberg
Simplify the function warn_if_unremovable slightly. Additionally, change behaviour slightly. If we failed to remove the object because the object does not exist, we can still return success back to the caller since none of the callers depend on "fail if the file did not exist". Signed-off-by: Ronnie Sahlberg <sahlberg@google.com> Signed-off-by: Jonathan Nieder <jrnieder@gmail.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2014-10-01commit_packed_refs(): reimplement using fdopen_lock_file()Michael Haggerty
Signed-off-by: Michael Haggerty <mhagger@alum.mit.edu> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2014-10-01lockfile.h: extract new header file for the functions in lockfile.cMichael Haggerty
Move the interface declaration for the functions in lockfile.c from cache.h to a new file, lockfile.h. Add #includes where necessary (and remove some redundant includes of cache.h by files that already include builtin.h). Move the documentation of the lock_file state diagram from lockfile.c to the new header file. Signed-off-by: Michael Haggerty <mhagger@alum.mit.edu> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2014-10-01get_locked_file_path(): new functionMichael Haggerty
Add a function to return the path of the file that is locked by a lock_file object. This reduces the knowledge that callers have to have about the lock_file layout. Suggested-by: Ronnie Sahlberg <sahlberg@google.com> Signed-off-by: Michael Haggerty <mhagger@alum.mit.edu> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2014-10-01lockfile: rename LOCK_NODEREF to LOCK_NO_DEREFMichael Haggerty
This makes it harder to misread the name as LOCK_NODE_REF. Suggested-by: Torsten Bögershausen <tboegi@web.de> Signed-off-by: Michael Haggerty <mhagger@alum.mit.edu> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2014-10-01lockfile: change lock_file::filename into a strbufMichael Haggerty
For now, we still make sure to allocate at least PATH_MAX characters for the strbuf because resolve_symlink() doesn't know how to expand the space for its return value. (That will be fixed in a moment.) Another alternative would be to just use a strbuf as scratch space in lock_file() but then store a pointer to the naked string in struct lock_file. But lock_file objects are often reused. By reusing the same strbuf, we can avoid having to reallocate the string most times when a lock_file object is reused. Helped-by: Torsten Bögershausen <tboegi@web.de> Signed-off-by: Michael Haggerty <mhagger@alum.mit.edu> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2014-10-01delete_ref_loose(): don't muck around in the lock_file's filenameMichael Haggerty
It's bad manners. Especially since there could be a signal during the call to unlink_or_warn(), in which case the signal handler will see the wrong filename and delete the reference file, leaving the lockfile behind. So make our own copy to work with. Signed-off-by: Michael Haggerty <mhagger@alum.mit.edu> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2014-10-01cache.h: define constants LOCK_SUFFIX and LOCK_SUFFIX_LENMichael Haggerty
There are a few places that use these values, so define constants for them. Signed-off-by: Michael Haggerty <mhagger@alum.mit.edu> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2014-10-01unable_to_lock_die(): rename function from unable_to_lock_index_die()Michael Haggerty
This function is used for other things besides the index, so rename it accordingly. Suggested-by: Jeff King <peff@peff.net> Signed-off-by: Michael Haggerty <mhagger@alum.mit.edu> Reviewed-by: Ronnie Sahlberg <sahlberg@google.com> Reviewed-by: Jonathan Nieder <jrnieder@gmail.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2014-09-29Merge branch 'da/rev-parse-verify-quiet'Junio C Hamano
"rev-parse --verify --quiet $name" is meant to quietly exit with a non-zero status when $name is not a valid object name, but still gave error messages in some cases. * da/rev-parse-verify-quiet: stash: prefer --quiet over shell redirection of the standard error stream refs: make rev-parse --quiet actually quiet t1503: use test_must_be_empty Documentation: a note about stdout for git rev-parse --verify --quiet
2014-09-26Merge branch 'jk/faster-name-conflicts'Junio C Hamano
Optimize the check to see if a ref $F can be created by making sure no existing ref has $F/ as its prefix, which especially matters in a repository with a large number of existing refs. * jk/faster-name-conflicts: refs: speed up is_refname_available
2014-09-26Merge branch 'jk/write-packed-refs-via-stdio'Junio C Hamano
Optimize the code path to write out the packed-refs file, which especially matters in a repository with a large number of refs. * jk/write-packed-refs-via-stdio: refs: write packed_refs file using stdio
2014-09-19Merge branch 'jk/prune-top-level-refs-after-packing' into maintJunio C Hamano
* jk/prune-top-level-refs-after-packing: pack-refs: prune top-level refs like "refs/foo"
2014-09-19refs: make rev-parse --quiet actually quietDavid Aguilar
When a reflog is deleted, e.g. when "git stash" clears its stashes, "git rev-parse --verify --quiet" dies: fatal: Log for refs/stash is empty. The reason is that the get_sha1() code path does not allow us to suppress this message. Pass the flags bitfield through get_sha1_with_context() so that read_ref_at() can suppress the message. Use get_sha1_with_context1() instead of get_sha1() in rev-parse so that the --quiet flag is honored. Signed-off-by: David Aguilar <davvid@gmail.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2014-09-12refs: speed up is_refname_availableJeff King
Our filesystem ref storage does not allow D/F conflicts; so if "refs/heads/a/b" exists, we do not allow "refs/heads/a" to exist (and vice versa). This falls out naturally for loose refs, where the filesystem enforces the condition. But for packed-refs, we have to make the check ourselves. We do so by iterating over the entire packed-refs namespace and checking whether each name creates a conflict. If you have a very large number of refs, this is quite inefficient, as you end up doing a large number of comparisons with uninteresting bits of the ref tree (e.g., we know that all of "refs/tags" is uninteresting in the example above, yet we check each entry in it). Instead, let's take advantage of the fact that we have the packed refs stored as a trie of ref_entry structs. We can find each component of the proposed refname as we walk through the trie, checking for D/F conflicts as we go. For a refname of depth N (i.e., 4 in the above example), we only have to visit N nodes. And at each visit, we can binary search the M names at that level, for a total complexity of O(N lg M). ("M" is different at each level, of course, but we can take the worst-case "M" as a bound). In a pathological case of fetching 30,000 fresh refs into a repository with 8.5 million refs, this dropped the time to run "git fetch" from tens of minutes to ~30s. This may also help smaller cases in which we check against loose refs (which we do when renaming a ref), as we may avoid a disk access for unrelated loose directories. Note that the tests we add appear at first glance to be redundant with what is already in t3210. However, the early tests are not robust; they are run with reflogs turned on, meaning that we are not actually testing is_refname_available at all! The operations will still fail because the reflogs will hit D/F conflicts in the filesystem. To get a true test, we must turn off reflogs (but we don't want to do so for the entire script, because the point of turning them on was to cover some other cases). Reviewed-by: Michael Haggerty <mhagger@alum.mit.edu> Signed-off-by: Jeff King <peff@peff.net> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2014-09-11Merge branch 'jk/prune-top-level-refs-after-packing'Junio C Hamano
After "pack-refs --prune" packed refs at the top-level, it failed to prune them. * jk/prune-top-level-refs-after-packing: pack-refs: prune top-level refs like "refs/foo"
2014-09-11Merge branch 'rs/ref-transaction-1'Junio C Hamano
The second batch of the transactional ref update series. * rs/ref-transaction-1: (22 commits) update-ref --stdin: pass transaction around explicitly update-ref --stdin: narrow scope of err strbuf refs.c: make delete_ref use a transaction refs.c: make prune_ref use a transaction to delete the ref refs.c: remove lock_ref_sha1 refs.c: remove the update_ref_write function refs.c: remove the update_ref_lock function refs.c: make lock_ref_sha1 static walker.c: use ref transaction for ref updates fast-import.c: use a ref transaction when dumping tags receive-pack.c: use a reference transaction for updating the refs refs.c: change update_ref to use a transaction branch.c: use ref transaction for all ref updates fast-import.c: change update_branch to use ref transactions sequencer.c: use ref transactions for all ref updates commit.c: use ref transactions for updates replace.c: use the ref transaction functions for updates tag.c: use ref transactions when doing updates refs.c: add transaction.status and track OPEN/CLOSED refs.c: make ref_transaction_begin take an err argument ...
2014-09-10refs: write packed_refs file using stdioJeff King
We write each line of a new packed-refs file individually using a write() syscall (and sometimes 2, if the ref is peeled). Since each line is only about 50-100 bytes long, this creates a lot of system call overhead. We can instead open a stdio handle around our descriptor and use fprintf to write to it. The extra buffering is not a problem for us, because nobody will read our new packed-refs file until we call commit_lock_file (by which point we have flushed everything). On a pathological repository with 8.5 million refs, this dropped the time to run `git pack-refs` from 20s to 6s. Signed-off-by: Jeff King <peff@peff.net> Reviewed-by: Michael Haggerty <mhagger@alum.mit.edu> Signed-off-by: Junio C Hamano <gitster@pobox.com>