git/replace-object.h, branch v2.48.2

Merge branch 'en/header-split-cache-h-part-3'

2023-06-29T23:43:21Z

Header files cleanup. * en/header-split-cache-h-part-3: (28 commits) fsmonitor-ll.h: split this header out of fsmonitor.h hash-ll, hashmap: move oidhash() to hash-ll object-store-ll.h: split this header out of object-store.h khash: name the structs that khash declares merge-ll: rename from ll-merge git-compat-util.h: remove unneccessary include of wildmatch.h builtin.h: remove unneccessary includes list-objects-filter-options.h: remove unneccessary include diff.h: remove unnecessary include of oidset.h repository: remove unnecessary include of path.h log-tree: replace include of revision.h with simple forward declaration cache.h: remove this no-longer-used header read-cache*.h: move declarations for read-cache.c functions from cache.h repository.h: move declaration of the_index from cache.h merge.h: move declarations for merge.c from cache.h diff.h: move declaration for global in diff.c from cache.h preload-index.h: move declarations for preload-index.c from elsewhere sparse-index.h: move declarations for sparse-index.c from cache.h name-hash.h: move declarations for name-hash.c from cache.h run-command.h: move declarations for run-command.c from cache.h ...

object-store-ll.h: split this header out of object-store.h

2023-06-21T20:39:54Z

The vast majority of files including object-store.h did not need dir.h nor khash.h. Split the header into two files, and let most just depend upon object-store-ll.h, while letting the two callers that need it depend on the full object-store.h. After this patch: $ git grep -h include..object-store | sort | uniq -c 2 #include "object-store.h" 129 #include "object-store-ll.h" Diff best viewed with `--color-moved`. Signed-off-by: Elijah Newren Signed-off-by: Junio C Hamano

repository: create read_replace_refs setting

2023-06-12T20:34:55Z

The 'read_replace_refs' global specifies whether or not we should respect the references of the form 'refs/replace/' to replace which object we look up when asking for ''. This global has caused issues when it is not initialized properly, such as in b6551feadfd (merge-tree: load default git config, 2023-05-10). To make this more robust, move its config-based initialization out of git_default_config and into prepare_repo_settings(). This provides a repository-scoped version of the 'read_replace_refs' global. The global still has its purpose: it is disabled process-wide by the GIT_NO_REPLACE_OBJECTS environment variable or by a call to disable_replace_refs() in some specific Git commands. Since we already encapsulated the use of the constant inside replace_refs_enabled(), we can perform the initialization inside that method, if necessary. This solves the problem of forgetting to check the config, as we will check it before returning this value. Due to this encapsulation, the global can move to be static within replace-object.c. There is an interesting behavior change possible here: we now have a repository-scoped understanding of this config value. Thus, if there was a command that recurses into submodules and might follow replace refs, then it would now respect the core.useReplaceRefs config value in each repository. 'git grep --recurse-submodules' is such a command that recurses into submodules in-process. We can demonstrate the granularity of this config value via a test in t7814. Signed-off-by: Derrick Stolee Signed-off-by: Junio C Hamano

replace-objects: create wrapper around setting

2023-06-12T20:34:55Z

The 'read_replace_objects' constant is initialized by git_default_config (if core.useReplaceRefs is disabled) and within setup_git_env (if GIT_NO_REPLACE_OBJECTS) is set. To ensure that this variable cannot be set accidentally in other places, wrap it in a replace_refs_enabled() method. Since we still assign this global in config.c, we are not able to remove the global scope of this variable and make it a static within replace-object.c. This will happen in a later change which will also prevent the variable from being read before it is initialized. Centralizing read access to the variable is an important first step. Signed-off-by: Derrick Stolee Signed-off-by: Junio C Hamano

repository: create disable_replace_refs()

2023-06-12T20:34:55Z

Several builtins depend on being able to disable the replace references so we actually operate on each object individually. These currently do so by directly mutating the 'read_replace_refs' global. A future change will move this global into a different place, so it will be necessary to change all of these lines. However, we can simplify that transition by abstracting the purpose of these global assignments with a method call. We will need to keep this read_replace_refs global forever, as we want to make sure that we never use replace refs throughout the life of the process if this method is called. Future changes may present a repository-scoped version of the variable to represent that repository's core.useReplaceRefs config value, but a zero-valued read_replace_refs will always override such a setting. Signed-off-by: Derrick Stolee Signed-off-by: Junio C Hamano

replace-object.h: move read_replace_refs declaration from cache.h to here

2023-02-24T01:25:30Z

Adjust several files to be more explicit about their dependency on replace-objects to accommodate this change. Signed-off-by: Elijah Newren Signed-off-by: Junio C Hamano

object-store.h: move struct object_info from cache.h

2023-02-24T01:25:29Z

Move struct object_info, and a few related #define's from cache.h to object-store.h. A surprising effect of this change is that replace-object.h, which includes object-store.h, now needs to directly include cache.h since that is where read_replace_refs is declared and that variable is used in one of its inline functions. The next commit will move that declaration and fix that unfortunate new direct inclusion of cache.h. Signed-off-by: Elijah Newren Signed-off-by: Junio C Hamano

replace-object: make replace operations thread-safe

2020-01-17T21:52:14Z

replace-object functions are very close to being thread-safe: the only current racy section is the lazy initialization at prepare_replace_object(). The following patches will protect some object reading operations to be called threaded, but before that, replace functions must be protected. To do so, add a mutex to struct raw_object_store and acquire it before lazy initializing the replace_map. This won't cause any noticeable performance drop as the mutex will no longer be used after the replace_map is initialized. Later, when the replace functions are called in parallel, thread debuggers might point our use of the added replace_map_initialized flag as a data race. However, as this boolean variable is initialized as false and it's only updated once, there's no real harm. It's perfectly fine if the value is updated right after a thread read it in replace-map.h:lookup_replace_object() (there'll only be a performance penalty for the affected threads at that moment). We could cease the debugger warning protecting the variable reading at the said function. However, this would negatively affect performance for all threads calling it, at any time, so it's not really worthy since the warning doesn't represent a real problem. Instead, to make sure we don't get false positives (at ThreadSanitizer, at least) an entry for the respective function is added to .tsan-suppressions. Signed-off-by: Matheus Tavares Signed-off-by: Junio C Hamano

*.[ch]: manually align parameter lists

2019-05-05T06:20:10Z

In previous patches, extern was mechanically removed from function declarations without care to formatting, causing parameter lists to be misaligned. Manually format changed sections such that the parameter lists should be realigned. Viewing this patch with 'git diff -w' should produce no output. Signed-off-by: Denton Liu Signed-off-by: Junio C Hamano

*.[ch]: remove extern from function declarations using spatch

2019-05-05T06:20:06Z

There has been a push to remove extern from function declarations. Remove some instances of "extern" for function declarations which are caught by Coccinelle. Note that Coccinelle has some difficulty with processing functions with `__attribute__` or varargs so some `extern` declarations are left behind to be dealt with in a future patch. This was the Coccinelle patch used: @@ type T; identifier f; @@ - extern T f(...); and it was run with: $ git ls-files \*.{c,h} | grep -v ^compat/ | xargs spatch --sp-file contrib/coccinelle/noextern.cocci --in-place Files under `compat/` are intentionally excluded as some are directly copied from external sources and we should avoid churning them as much as possible. Signed-off-by: Denton Liu Signed-off-by: Junio C Hamano