Welcome to mirror list, hosted at ThFree Co, Russian Federation.

git.kernel.org/pub/scm/git/git.git - Unnamed repository; edit this file 'description' to name the repository.
summaryrefslogtreecommitdiff
path: root/refs
AgeCommit message (Collapse)Author
2017-10-16refs/files-backend: convert static functions to object_idbrian m. carlson
Convert several static functions to take pointers to struct object_id. Change the relevant parameters to write_packed_entry to be const, as we don't modify them. Rename lock_ref_sha1_basic to lock_ref_oid_basic to reflect its new argument. Update the docstring for verify lock to account for the new parameter name, and note additionally that the old_oid may be NULL. Signed-off-by: brian m. carlson <sandals@crustytoothpaste.net> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2017-10-16refs: convert read_raw_ref backends to struct object_idbrian m. carlson
Convert the unsigned char * parameter to struct object_id * for files_read_raw_ref and packed_read_raw_ref. Update the documentation. Switch from using get_sha1_hex and a hard-coded 40 to using parse_oid_hex. Signed-off-by: brian m. carlson <sandals@crustytoothpaste.net> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2017-10-16refs: convert peel_object to struct object_idbrian m. carlson
Signed-off-by: brian m. carlson <sandals@crustytoothpaste.net> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2017-10-16refs: convert resolve_ref_unsafe to struct object_idbrian m. carlson
Convert resolve_ref_unsafe to take a pointer to struct object_id by converting one remaining caller to use struct object_id, removing the temporary NULL pointer check in expand_ref, converting the declaration and definition, and applying the following semantic patch: @@ expression E1, E2, E3, E4; @@ - resolve_ref_unsafe(E1, E2, E3.hash, E4) + resolve_ref_unsafe(E1, E2, &E3, E4) @@ expression E1, E2, E3, E4; @@ - resolve_ref_unsafe(E1, E2, E3->hash, E4) + resolve_ref_unsafe(E1, E2, E3, E4) Signed-off-by: brian m. carlson <sandals@crustytoothpaste.net> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2017-10-16refs: convert reflog_expire parameter to struct object_idbrian m. carlson
reflog_expire already used struct object_id internally, but it did not take it as a parameter. Adjust the parameter (and the callers) to pass a pointer to struct object_id instead of a pointer to unsigned char. Remove the temporary inserted earlier as it is no longer required. Signed-off-by: brian m. carlson <sandals@crustytoothpaste.net> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2017-10-16refs: convert read_ref and read_ref_full to object_idbrian m. carlson
All but two of the call sites already have parameters using the hash parameter of struct object_id, so convert them to take a pointer to the struct directly. Also convert refs_read_refs_full, the underlying implementation. Signed-off-by: brian m. carlson <sandals@crustytoothpaste.net> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2017-10-16refs: update ref transactions to use struct object_idbrian m. carlson
Update the ref transaction code to use struct object_id. Remove one NULL pointer check which was previously inserted around a dereference; since we now pass a pointer to struct object_id directly through, the code we're calling handles this for us. Signed-off-by: brian m. carlson <sandals@crustytoothpaste.net> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2017-10-16refs: convert delete_ref and refs_delete_ref to struct object_idbrian m. carlson
Convert delete_ref and refs_delete_ref to take a pointer to struct object_id. Update the documentation accordingly, including referring to null_oid in lowercase, as it is not a #define constant. Signed-off-by: brian m. carlson <sandals@crustytoothpaste.net> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2017-10-16refs/files-backend: convert struct ref_to_prune to object_idbrian m. carlson
Change the member of this struct to be a struct object_id. Signed-off-by: brian m. carlson <sandals@crustytoothpaste.net> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2017-10-05Merge branch 'rs/cleanup-strbuf-users'Junio C Hamano
Code clean-up. * rs/cleanup-strbuf-users: graph: use strbuf_addchars() to add spaces use strbuf_addstr() for adding strings to strbufs path: use strbuf_add_real_path()
2017-10-05Merge branch 'rs/resolve-ref-optional-result'Junio C Hamano
Code clean-up. * rs/resolve-ref-optional-result: refs: pass NULL to resolve_refdup() if hash is not needed refs: pass NULL to refs_resolve_refdup() if hash is not needed
2017-10-03Merge branch 'mh/mmap-packed-refs'Junio C Hamano
Operations that do not touch (majority of) packed refs have been optimized by making accesses to packed-refs file lazy; we no longer pre-parse everything, and an access to a single ref in the packed-refs does not touch majority of irrelevant refs, either. * mh/mmap-packed-refs: (21 commits) packed-backend.c: rename a bunch of things and update comments mmapped_ref_iterator: inline into `packed_ref_iterator` ref_cache: remove support for storing peeled values packed_ref_store: get rid of the `ref_cache` entirely ref_store: implement `refs_peel_ref()` generically packed_read_raw_ref(): read the reference from the mmapped buffer packed_ref_iterator_begin(): iterate using `mmapped_ref_iterator` read_packed_refs(): ensure that references are ordered when read packed_ref_cache: keep the `packed-refs` file mmapped if possible packed-backend.c: reorder some definitions mmapped_ref_iterator_advance(): no peeled value for broken refs mmapped_ref_iterator: add iterator over a packed-refs file packed_ref_cache: remember the file-wide peeling state read_packed_refs(): read references with minimal copying read_packed_refs(): make parsing of the header line more robust read_packed_refs(): only check for a header at the top of the file read_packed_refs(): use mmap to read the `packed-refs` file die_unterminated_line(), die_invalid_line(): new functions packed_ref_cache: add a backlink to the associated `packed_ref_store` prefix_ref_iterator: break when we leave the prefix ...
2017-10-03Merge branch 'jk/read-in-full'Junio C Hamano
Code clean-up to prevent future mistakes by copying and pasting code that checks the result of read_in_full() function. * jk/read-in-full: worktree: check the result of read_in_full() worktree: use xsize_t to access file size distinguish error versus short read from read_in_full() avoid looking at errno for short read_in_full() returns prefer "!=" when checking read_in_full() result notes-merge: drop dead zero-write code files-backend: prefer "0" for write_in_full() error check
2017-10-03Merge branch 'sd/branch-copy'Junio C Hamano
"git branch" learned "-c/-C" to create a new branch by copying an existing one. * sd/branch-copy: branch: fix "copy" to never touch HEAD branch: add a --copy (-c) option to go with --move (-m) branch: add test for -m renaming multiple config sections config: create a function to format section headers
2017-10-02use strbuf_addstr() for adding strings to strbufsRené Scharfe
Use strbuf_addstr() instead of strbuf_addf() for adding strings. That's simpler and makes the intent clearer. Patch generated by Coccinelle and contrib/coccinelle/strbuf.cocci; adjusted indentation in refs/packed-backend.c manually. Signed-off-by: Rene Scharfe <l.s.r@web.de> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2017-10-01refs: pass NULL to refs_resolve_refdup() if hash is not neededRené Scharfe
This gets us rid of a write-only variable. Signed-off-by: Rene Scharfe <l.s.r@web.de> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2017-09-28Merge branch 'rs/resolve-ref-optional-result'Junio C Hamano
Code clean-up. * rs/resolve-ref-optional-result: refs: pass NULL to resolve_ref_unsafe() if hash is not needed refs: pass NULL to refs_resolve_ref_unsafe() if hash is not needed refs: make sha1 output parameter of refs_resolve_ref_unsafe() optional
2017-09-26files-backend: prefer "0" for write_in_full() error checkJeff King
Commit 06f46f237a (avoid "write_in_full(fd, buf, len) != len" pattern, 2017-09-13) converted this callsite from: write_in_full(...) != 1 to write_in_full(...) < 0 But during the conflict resolution in c50424a6f0 (Merge branch 'jk/write-in-full-fix', 2017-09-25), this morphed into write_in_full(...) < 1 This behaves as we want, but we prefer to avoid modeling the "less than length" error-check which can be subtly buggy, as shown in efacf609c8 (config: avoid "write_in_full(fd, buf, len) < len" pattern, 2017-09-13). Signed-off-by: Jeff King <peff@peff.net> Reviewed-by: Jonathan Nieder <jrnieder@gmail.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2017-09-25packed-backend.c: rename a bunch of things and update commentsMichael Haggerty
We've made huge changes to this file, and some of the old names and comments are no longer very fitting. So rename a bunch of things: * `struct packed_ref_cache` → `struct snapshot` * `acquire_packed_ref_cache()` → `acquire_snapshot()` * `release_packed_ref_buffer()` → `clear_snapshot_buffer()` * `release_packed_ref_cache()` → `release_snapshot()` * `clear_packed_ref_cache()` → `clear_snapshot()` * `struct packed_ref_entry` → `struct snapshot_record` * `cmp_packed_ref_entries()` → `cmp_packed_ref_records()` * `cmp_entry_to_refname()` → `cmp_record_to_refname()` * `sort_packed_refs()` → `sort_snapshot()` * `read_packed_refs()` → `create_snapshot()` * `validate_packed_ref_cache()` → `validate_snapshot()` * `get_packed_ref_cache()` → `get_snapshot()` * Renamed local variables and struct members accordingly. Also update a bunch of comments to reflect the renaming and the accumulated changes that the code has undergone. Signed-off-by: Michael Haggerty <mhagger@alum.mit.edu> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2017-09-25mmapped_ref_iterator: inline into `packed_ref_iterator`Michael Haggerty
Since `packed_ref_iterator` is now delegating to `mmapped_ref_iterator` rather than `cache_ref_iterator` to do the heavy lifting, there is no need to keep the two iterators separate. So "inline" `mmapped_ref_iterator` into `packed_ref_iterator`. This removes a bunch of boilerplate. Signed-off-by: Michael Haggerty <mhagger@alum.mit.edu> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2017-09-25ref_cache: remove support for storing peeled valuesMichael Haggerty
Now that the `packed-refs` backend doesn't use `ref_cache`, there is nobody left who might want to store peeled values of references in `ref_cache`. So remove that feature. Signed-off-by: Michael Haggerty <mhagger@alum.mit.edu> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2017-09-25packed_ref_store: get rid of the `ref_cache` entirelyMichael Haggerty
Now that everything has been changed to read what it needs directly out of the `packed-refs` file, `packed_ref_store` doesn't need to maintain a `ref_cache` at all. So get rid of it. First of all, this will save a lot of memory and lots of little allocations. Instead of needing to store complicated parsed data structures in memory, we just mmap the file (potentially sharing memory with other processes) and parse only what we need. Moreover, since the mmapped access to the file reads only the parts of the file that it needs, this might save reading all of the data from disk at all (at least if the file starts out sorted). Signed-off-by: Michael Haggerty <mhagger@alum.mit.edu> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2017-09-25ref_store: implement `refs_peel_ref()` genericallyMichael Haggerty
We're about to stop storing packed refs in a `ref_cache`. That means that the only way we have left to optimize `peel_ref()` is by checking whether the reference being peeled is the one currently being iterated over (in `current_ref_iter`), and if so, using `ref_iterator_peel()`. But this can be done generically; it doesn't have to be implemented per-backend. So implement `refs_peel_ref()` in `refs.c` and remove the `peel_ref()` method from the refs API. This removes the last callers of a couple of functions, so delete them. More cleanup to come... Signed-off-by: Michael Haggerty <mhagger@alum.mit.edu> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2017-09-25packed_read_raw_ref(): read the reference from the mmapped bufferMichael Haggerty
Instead of reading the reference from the `ref_cache`, read it directly from the mmapped buffer. Signed-off-by: Michael Haggerty <mhagger@alum.mit.edu> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2017-09-25packed_ref_iterator_begin(): iterate using `mmapped_ref_iterator`Michael Haggerty
Now that we have an efficient way to iterate, in order, over the mmapped contents of the `packed-refs` file, we can use that directly to implement reference iteration for the `packed_ref_store`, rather than iterating over the `ref_cache`. This is the next step towards getting rid of the `ref_cache` entirely. Signed-off-by: Michael Haggerty <mhagger@alum.mit.edu> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2017-09-25read_packed_refs(): ensure that references are ordered when readMichael Haggerty
It doesn't actually matter now, because the references are only iterated over to fill the associated `ref_cache`, which itself puts them in the correct order. But we want to get rid of the `ref_cache`, so we want to be able to iterate directly over the `packed-refs` buffer, and then the iteration will need to be ordered correctly. In fact, we already write the `packed-refs` file sorted, but it is possible that other Git clients don't get it right. So let's not assume that a `packed-refs` file is sorted unless it is explicitly declared to be so via a `sorted` trait in its header line. If it is *not* declared to be sorted, then scan quickly through the file to check. If it is found to be out of order, then sort the records into a new memory-only copy. This checking and sorting is done quickly, without parsing the full file contents. However, it needs a little bit of care to avoid reading past the end of the buffer even if the `packed-refs` file is corrupt. Since *we* always write the file correctly sorted, include that trait when we write or rewrite a `packed-refs` file. This means that the scan described in the previous paragraph should only have to be done for `packed-refs` files that were written by older versions of the Git command-line client, or by other clients that haven't yet learned to write the `sorted` trait. If `packed-refs` was already sorted, then (if the system allows it) we can use the mmapped file contents directly. But if the system doesn't allow a file that is currently mmapped to be replaced using `rename()`, then it would be bad for us to keep the file mmapped for any longer than necessary. So, on such systems, always make a copy of the file contents, either as part of the sorting process, or afterwards. Signed-off-by: Michael Haggerty <mhagger@alum.mit.edu> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2017-09-25packed_ref_cache: keep the `packed-refs` file mmapped if possibleMichael Haggerty
Keep a copy of the `packed-refs` file contents in memory for as long as a `packed_ref_cache` object is in use: * If the system allows it, keep the `packed-refs` file mmapped. * If not (either because the system doesn't support `mmap()` at all, or because a file that is currently mmapped cannot be replaced via `rename()`), then make a copy of the file's contents in heap-allocated space, and keep that around instead. We base the choice of behavior on a new build-time switch, `MMAP_PREVENTS_DELETE`. By default, this switch is set for Windows variants. After this commit, `MMAP_NONE` and `MMAP_TEMPORARY` are still handled identically. But the next commit will introduce a difference. This whole change is still pointless, because we only read the `packed-refs` file contents immediately after instantiating the `packed_ref_cache`. But that will soon change. Signed-off-by: Michael Haggerty <mhagger@alum.mit.edu> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2017-09-25packed-backend.c: reorder some definitionsMichael Haggerty
No code has been changed. This will make subsequent patches more self-contained. Signed-off-by: Michael Haggerty <mhagger@alum.mit.edu> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2017-09-25mmapped_ref_iterator_advance(): no peeled value for broken refsMichael Haggerty
If a reference is broken, suppress its peeled value. Signed-off-by: Michael Haggerty <mhagger@alum.mit.edu> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2017-09-25mmapped_ref_iterator: add iterator over a packed-refs fileMichael Haggerty
Add a new `mmapped_ref_iterator`, which can iterate over the references in an mmapped `packed-refs` file directly. Use this iterator from `read_packed_refs()` to fill the packed refs cache. Note that we are not yet willing to promise that the new iterator generates its output in order. That doesn't matter for now, because the packed refs cache doesn't care what order it is filled. This change adds a lot of boilerplate without providing any obvious benefits. The benefits will come soon, when we get rid of the `ref_cache` for packed references altogether. Signed-off-by: Michael Haggerty <mhagger@alum.mit.edu> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2017-09-25packed_ref_cache: remember the file-wide peeling stateMichael Haggerty
Rather than store the peeling state (i.e., the one defined by traits in the `packed-refs` file header line) in a local variable in `read_packed_refs()`, store it permanently in `packed_ref_cache`. This will be needed when we stop reading all packed refs at once. Signed-off-by: Michael Haggerty <mhagger@alum.mit.edu> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2017-09-25read_packed_refs(): read references with minimal copyingMichael Haggerty
Instead of copying data from the `packed-refs` file one line at time and then processing it, process the data in place as much as possible. Also, instead of processing one line per iteration of the main loop, process a reference line plus its corresponding peeled line (if present) together. Note that this change slightly tightens up the parsing of the `packed-refs` file. Previously, the parser would have accepted multiple "peeled" lines for a single reference (ignoring all but the last one). Now it would reject that. Signed-off-by: Michael Haggerty <mhagger@alum.mit.edu> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2017-09-25Merge branch 'jk/write-in-full-fix'Junio C Hamano
Many codepaths did not diagnose write failures correctly when disks go full, due to their misuse of write_in_full() helper function, which have been corrected. * jk/write-in-full-fix: read_pack_header: handle signed/unsigned comparison in read result config: flip return value of store_write_*() notes-merge: use ssize_t for write_in_full() return value pkt-line: check write_in_full() errors against "< 0" convert less-trivial versions of "write_in_full() != len" avoid "write_in_full(fd, buf, len) != len" pattern get-tar-commit-id: check write_in_full() return against 0 config: avoid "write_in_full(fd, buf, len) < len" pattern
2017-09-24refs: pass NULL to refs_resolve_ref_unsafe() if hash is not neededRené Scharfe
This allows us to get rid of two write-only variables, one of them being a SHA1 buffer. Signed-off-by: Rene Scharfe <l.s.r@web.de> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2017-09-19Merge branch 'mh/packed-ref-transactions'Junio C Hamano
Implement transactional update to the packed-ref representation of references. * mh/packed-ref-transactions: files_transaction_finish(): delete reflogs before references packed-backend: rip out some now-unused code files_ref_store: use a transaction to update packed refs t1404: demonstrate two problems with reference transactions files_initial_transaction_commit(): use a transaction for packed refs prune_refs(): also free the linked list files_pack_refs(): use a reference transaction to write packed refs packed_delete_refs(): implement method packed_ref_store: implement reference transactions struct ref_transaction: add a place for backends to store data packed-backend: don't adjust the reference count on lock/unlock
2017-09-19Merge branch 'jk/incore-lockfile-removal'Junio C Hamano
The long-standing rule that an in-core lockfile instance, once it is used, must not be freed, has been lifted and the lockfile and tempfile APIs have been updated to reduce the chance of programming errors. * jk/incore-lockfile-removal: stop leaking lock structs in some simple cases ref_lock: stop leaking lock_files lockfile: update lifetime requirements in documentation tempfile: auto-allocate tempfiles on heap tempfile: remove deactivated list entries tempfile: use list.h for linked list tempfile: release deactivated strbufs instead of resetting tempfile: robustify cleanup handler tempfile: factor out deactivation tempfile: factor out activation tempfile: replace die("BUG") with BUG() tempfile: handle NULL tempfile pointers gracefully tempfile: prefer is_tempfile_active to bare access lockfile: do not rollback lock on failed close tempfile: do not delete tempfile on failed close always check return value of close_tempfile verify_signed_buffer: prefer close_tempfile() to close() setup_temporary_shallow: move tempfile struct into function setup_temporary_shallow: avoid using inactive tempfile write_index_as_tree: cleanup tempfile on error
2017-09-19Merge branch 'nd/prune-in-worktree'Junio C Hamano
"git gc" and friends when multiple worktrees are used off of a single repository did not consider the index and per-worktree refs of other worktrees as the root for reachability traversal, making objects that are in use only in other worktrees to be subject to garbage collection. * nd/prune-in-worktree: refs.c: reindent get_submodule_ref_store() refs.c: remove fallback-to-main-store code get_submodule_ref_store() rev-list: expose and document --single-worktree revision.c: --reflog add HEAD reflog from all worktrees files-backend: make reflog iterator go through per-worktree reflog revision.c: --all adds HEAD from all worktrees refs: remove dead for_each_*_submodule() refs.c: move for_each_remote_ref_submodule() to submodule.c revision.c: use refs_for_each*() instead of for_each_*_submodule() refs: add refs_head_ref() refs: move submodule slash stripping code to get_submodule_ref_store refs.c: refactor get_submodule_ref_store(), share common free block revision.c: --indexed-objects add objects from all worktrees revision.c: refactor add_index_objects_to_pending() refs.c: use is_dir_sep() in resolve_gitlink_ref() revision.h: new flag in struct rev_info wrt. worktree-related refs
2017-09-19Merge branch 'ma/split-symref-update-fix'Junio C Hamano
A leakfix. * ma/split-symref-update-fix: refs/files-backend: add `refname`, not "HEAD", to list refs/files-backend: correct return value in lock_ref_for_update refs/files-backend: fix memory leak in lock_ref_for_update refs/files-backend: add longer-scoped copy of string to list
2017-09-14read_packed_refs(): make parsing of the header line more robustMichael Haggerty
The old code parsed the traits in the `packed-refs` header by looking for the string " trait " (i.e., the name of the trait with a space on either side) in the header line. This is fragile, because if any other implementation of Git forgets to write the trailing space, the last trait would silently be ignored (and the error might never be noticed). So instead, use `string_list_split_in_place()` to split the traits into tokens then use `unsorted_string_list_has_string()` to look for the tokens we are interested in. This means that we can read the traits correctly even if the header line is missing a trailing space (or indeed, if it is missing the space after the colon, or if it has multiple spaces somewhere). However, older Git clients (and perhaps other Git implementations) still require the surrounding spaces, so we still have to output the header with a trailing space. Signed-off-by: Michael Haggerty <mhagger@alum.mit.edu> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2017-09-14read_packed_refs(): only check for a header at the top of the fileMichael Haggerty
This tightens up the parsing a bit; previously, stray header-looking lines would have been processed. Signed-off-by: Michael Haggerty <mhagger@alum.mit.edu> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2017-09-14read_packed_refs(): use mmap to read the `packed-refs` fileMichael Haggerty
It's still done in a pretty stupid way, involving more data copying than necessary. That will improve in future commits. Signed-off-by: Michael Haggerty <mhagger@alum.mit.edu> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2017-09-14die_unterminated_line(), die_invalid_line(): new functionsMichael Haggerty
Extract some helper functions for reporting errors. While we're at it, prevent them from spewing unlimited output to the terminal. These functions will soon have more callers. These functions accept the problematic line as a `(ptr, len)` pair rather than a NUL-terminated string, and `die_invalid_line()` checks for an EOL itself, because these calling conventions will be convenient for future callers. (Efficiency is not a concern here because these functions are only ever called if the `packed-refs` file is corrupt.) Signed-off-by: Michael Haggerty <mhagger@alum.mit.edu> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2017-09-14packed_ref_cache: add a backlink to the associated `packed_ref_store`Michael Haggerty
It will prove convenient in upcoming patches. Signed-off-by: Michael Haggerty <mhagger@alum.mit.edu> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2017-09-14prefix_ref_iterator: break when we leave the prefixJeff King
If the underlying iterator is ordered, then `prefix_ref_iterator` can stop as soon as it sees a refname that comes after the prefix. This will rarely make a big difference now, because `ref_cache_iterator` only iterates over the directory containing the prefix (and usually the prefix will span a whole directory anyway). But if *hint, hint* a future reference backend doesn't itself know where to stop the iteration, then this optimization will be a big win. Note that there is no guarantee that the underlying iterator doesn't include output preceding the prefix, so we have to skip over any unwanted references before we get to the ones that we want. Signed-off-by: Jeff King <peff@peff.net> Signed-off-by: Michael Haggerty <mhagger@alum.mit.edu> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2017-09-14ref_iterator: keep track of whether the iterator output is orderedMichael Haggerty
References are iterated over in order by refname, but reflogs are not. Some consumers of reference iteration care about the difference. Teach each `ref_iterator` to keep track of whether its output is ordered. `overlay_ref_iterator` is one of the picky consumers. Add a sanity check in `overlay_ref_iterator_begin()` to verify that its inputs are ordered. Signed-off-by: Michael Haggerty <mhagger@alum.mit.edu> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2017-09-14convert less-trivial versions of "write_in_full() != len"Jeff King
The prior commit converted many sites to check the return value of write_in_full() for negativity, rather than a mismatch with the input length. This patch covers similar cases, but where the return value is stored in an intermediate variable. These should get the same treatment, but they need to be reviewed more carefully since it would be a bug if the return value is stored in an unsigned type (which indeed, it is in one of the cases). Signed-off-by: Jeff King <peff@peff.net> Reviewed-by: Jonathan Nieder <jrnieder@gmail.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2017-09-14avoid "write_in_full(fd, buf, len) != len" patternJeff King
The return value of write_in_full() is either "-1", or the requested number of bytes[1]. If we make a partial write before seeing an error, we still return -1, not a partial value. This goes back to f6aa66cb95 (write_in_full: really write in full or return error on disk full., 2007-01-11). So checking anything except "was the return value negative" is pointless. And there are a couple of reasons not to do so: 1. It can do a funny signed/unsigned comparison. If your "len" is signed (e.g., a size_t) then the compiler will promote the "-1" to its unsigned variant. This works out for "!= len" (unless you really were trying to write the maximum size_t bytes), but is a bug if you check "< len" (an example of which was fixed recently in config.c). We should avoid promoting the mental model that you need to check the length at all, so that new sites are not tempted to copy us. 2. Checking for a negative value is shorter to type, especially when the length is an expression. 3. Linus says so. In d34cf19b89 (Clean up write_in_full() users, 2007-01-11), right after the write_in_full() semantics were changed, he wrote: I really wish every "write_in_full()" user would just check against "<0" now, but this fixes the nasty and stupid ones. Appeals to authority aside, this makes it clear that writing it this way does not have an intentional benefit. It's a historical curiosity that we never bothered to clean up (and which was undoubtedly cargo-culted into new sites). So let's convert these obviously-correct cases (this includes write_str_in_full(), which is just a wrapper for write_in_full()). [1] A careful reader may notice there is one way that write_in_full() can return a different value. If we ask write() to write N bytes and get a return value that is _larger_ than N, we could return a larger total. But besides the fact that this would imply a totally broken version of write(), it would already invoke undefined behavior. Our internal remaining counter is an unsigned size_t, which means that subtracting too many byte will wrap it around to a very large number. So we'll instantly begin reading off the end of the buffer, trying to write gigabytes (or petabytes) of data. Signed-off-by: Jeff King <peff@peff.net> Reviewed-by: Jonathan Nieder <jrnieder@gmail.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2017-09-10refs/files-backend: add `refname`, not "HEAD", to listMartin Ågren
An earlier patch rewrote `split_symref_update()` to add a copy of a string to a string list instead of adding the original string. That was so that the original string could be freed in a later patch, but it is also conceptually cleaner, since now all calls to `string_list_insert()` and `string_list_append()` add `update->refname`. --- Except a literal "HEAD" is added in `split_head_update()`. Restructure `split_head_update()` in the same way as the earlier patch did for `split_symref_update()`. This does not correct any practical problem, but makes things conceptually cleaner. The downside is a call to `string_list_has_string()`, which should be relatively cheap. Signed-off-by: Jeff King <peff@peff.net> Signed-off-by: Martin Ågren <martin.agren@gmail.com> Reviewed-by: Jeff King <peff@peff.net> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2017-09-10refs/files-backend: correct return value in lock_ref_for_updateMartin Ågren
In one code path we return a literal -1 and not a symbolic constant. The value -1 would be interpreted as TRANSACTION_NAME_CONFLICT, which is wrong. Use TRANSACTION_GENERIC_ERROR instead (that is the only other return value we have to choose from). Noticed-by: Michael Haggerty <mhagger@alum.mit.edu> Reviewed-by: Michael Haggerty <mhagger@alum.mit.edu> Signed-off-by: Martin Ågren <martin.agren@gmail.com> Reviewed-by: Jeff King <peff@peff.net> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2017-09-10refs/files-backend: fix memory leak in lock_ref_for_updateMartin Ågren
After the previous patch, none of the functions we call hold on to `referent.buf`, so we can safely release the string buffer before returning. Reviewed-by: Michael Haggerty <mhagger@alum.mit.edu> Signed-off-by: Martin Ågren <martin.agren@gmail.com> Reviewed-by: Jeff King <peff@peff.net> Signed-off-by: Junio C Hamano <gitster@pobox.com>