[PATCH v8 00/10] packfile: avoid using the 'the_repository' global variable
- From
Karthik Nayak <karthik.188@gmail.com>
- Date
- Nov 22, 2024, 10:08 UTC
- Message-ID
- <cover.1732269840.git.karthik.188@gmail.com>
- In-Reply-To
- <cover.1729504640.git.karthik.188@gmail.com>
The `packfile.c` file uses the global variable 'the_repository' extensively throughout the code. Let's remove all usecases of this, by modifying the required functions to accept a 'struct repository' instead. This is to clean up usage of global state.
The first 3 patches are mostly internal to `packfile.c`, we add the repository field to the `packed_git` struct and this is used to clear up some useages of the global variables.
The next 3 patches are more disruptive, they modify the function definition of `odb_pack_name`, `has_object[_kept]_pack` and `for_each_packed_object` to receive a repository, helping remove other usages of 'the_repository' variable.
Finally, the next two patches deal with global config values. These values are localized. The last patch is removal of an unecessary call to `prepare_packed_git()`. For v5 onwards, I've rebased the series off the master: 8f8d6eee53 (The seventh batch, 2024-11-01), as a dependency for this series 'jk/dumb-http-finalize' was merged to master. I've found no conflicts while merging with seen & next. But since this series does touch multiple files, there could be future conflicts.
Changes in v8: - Fix typos in comments - For packfile.c use delta_base_cache_limit from the repository settings, this avoids loading the config in hot paths. - Rename `longval` to `ulongval` to better signify the type.
Changes in v7: - Cleanup stale commit message. - Add missing space in `if` statement. - Fix typo s/incase/in case/.
Changes in v6: - Lazy load repository settings in packfile.c. This ensures that the settings are available for sure and we do not rely on callees setting it. - Use `size_t` for `delta_base_cache_limit`.
Changes in v5: - Move packed_git* settings to repo_settings to ensure we don't keep reparsing the settings in `use_pack`.
Changes in v4: - Renamed the repository field within `packed_git` and `multi_pack_index` from `r` to `repo`, while keeping function parameters to be `r`. - Fixed bad braces.
Changes in v3: - Improved commit messages. In the first commit to talk about how packed_git struct could also be part of the alternates of a repository. In the 7th commit to talk about the motive behind removing the global variable. - Changed 'packed_git->repo' to 'packed_git->r' to keep it consistent with the rest of the code base. - Replaced 'the_repository' with locally available access to the repository struct in multiple regions. - Removed unecessary inclusion of the 'repository.h' header file by forward declaring the 'repository' struct. - Replace memcpy with hashcpy. - Change the logic in the 7th patch to use if else statements. - Added an extra commit to cleanup `pack-bitmap.c`.
Karthik Nayak (9): packfile: add repository to struct `packed_git` packfile: use `repository` from `packed_git` directly packfile: pass `repository` to static function in the file packfile: pass down repository to `odb_pack_name` packfile: pass down repository to `has_object[_kept]_pack` packfile: pass down repository to `for_each_packed_object` config: make `delta_base_cache_limit` a non-global variable config: make `packed_git_(limit|window_size)` non-global variables midx: add repository to `multi_pack_index` struct
Taylor Blau (1): packfile.c: remove unnecessary prepare_packed_git() call
builtin/cat-file.c | 7 +- builtin/count-objects.c | 2 +- builtin/fast-import.c | 15 ++-- builtin/fsck.c | 20 +++--- builtin/gc.c | 8 ++- builtin/index-pack.c | 20 ++++-- builtin/pack-objects.c | 11 +-- builtin/pack-redundant.c | 2 +- builtin/repack.c | 2 +- builtin/rev-list.c | 2 +- commit-graph.c | 4 +- config.c | 22 ------ connected.c | 3 +- diff.c | 3 +- environment.c | 3 - environment.h | 1 - fsck.c | 2 +- http.c | 4 +- list-objects.c | 7 +- midx-write.c | 2 +- midx.c | 3 +- midx.h | 3 + object-store-ll.h | 9 ++- pack-bitmap.c | 90 ++++++++++++++---------- pack-objects.h | 3 +- pack-write.c | 1 + pack.h | 2 + packfile.c | 144 ++++++++++++++++++++++----------------- packfile.h | 18 +++-- promisor-remote.c | 2 +- prune-packed.c | 2 +- reachable.c | 4 +- repo-settings.c | 18 +++++ repo-settings.h | 7 ++ revision.c | 13 ++-- tag.c | 2 +- 36 files changed, 271 insertions(+), 190 deletions(-)
Range-diff against v7:
1: 6c00e25c86 ! 1: d1fdd6996a packfile: add repository to struct `packed_git`
@@ object-store-ll.h: struct packed_git {
const uint32_t *mtimes_map;
size_t mtimes_size;
+
-+ /* repo dentoes the repository this packed file belongs to */
++ /* repo denotes the repository this packfile belongs to */
+ struct repository *repo;
+
/* something like ".git/objects/pack/xxxxx.pack" */
2: 70fc8a79af = 2: 65c09858ce packfile: use `repository` from `packed_git` directly
3: 167a1f3a11 = 3: 80632934d1 packfile: pass `repository` to static function in the file
4: b7cfe78217 = 4: 67d71eab83 packfile: pass down repository to `odb_pack_name`
5: 5566f5554c = 5: ee210fa153 packfile: pass down repository to `has_object[_kept]_pack`
6: 1b26e45a9b = 6: 8db7094f4e packfile: pass down repository to `for_each_packed_object`
7: 1bdc34f4d8 ! 7: d1b6e8801b config: make `delta_base_cache_limit` a non-global variable
@@ Commit message
The `delta_base_cache_limit` variable is a global config variable used
by multiple subsystems. Let's make this non-global, by adding this
- variable to the stack of each of the subsystems where it is used.
+ variable independently to the subsystems where it is used.
- In `gc.c` we add it to the `gc_config` struct and also the constructor
- function. In `index-pack.c` we add it to the `pack_idx_option` struct
- and its constructor. Finally, in `packfile.c` we dynamically retrieve
- this value from the repository config, since the value is only used once
- in the entire subsystem.
+ First, add the setting to the `repo_settings` struct, this provides
+ access to the config in places where the repository is available. Use
+ this in `packfile.c`.
+
+ In `index-pack.c` we add it to the `pack_idx_option` struct and its
+ constructor. While the repository struct is available here, it may not
+ be set because `git index-pack` can be used without a repository.
+
+ In `gc.c` add it to the `gc_config` struct and also the constructor
+ function. The gc functions currently do not have direct access to a
+ repository struct.
These changes are made to remove the usage of `delta_base_cache_limit`
as a global variable in `packfile.c`. This brings us one step closer to
@@ pack.h: struct pack_idx_option {
*/
int anomaly_alloc, anomaly_nr;
uint32_t *anomaly;
-+ unsigned long delta_base_cache_limit;
++
++ size_t delta_base_cache_limit;
};
void reset_pack_idx_option(struct pack_idx_option *);
## packfile.c ##
-@@
- #include "commit-graph.h"
- #include "pack-revindex.h"
- #include "promisor-remote.h"
-+#include "config.h"
-+#include "pack-objects.h"
-
- char *odb_pack_name(struct repository *r, struct strbuf *buf,
- const unsigned char *hash, const char *ext)
@@ packfile.c: void clear_delta_base_cache(void)
}
@@ packfile.c: void clear_delta_base_cache(void)
struct delta_base_cache_entry *ent;
struct list_head *lru, *tmp;
@@ packfile.c: void *unpack_entry(struct repository *r, struct packed_git *p, off_t obj_offset,
- struct unpack_entry_stack_ent *delta_stack = small_delta_stack;
int delta_stack_nr = 0, delta_stack_alloc = UNPACK_ENTRY_STACK_PREALLOC;
int base_from_cache = 0;
-+ unsigned long delta_base_cache_limit = DEFAULT_DELTA_BASE_CACHE_LIMIT;
-+
-+ repo_config_get_ulong(r, "core.deltabasecachelimit", &delta_base_cache_limit);
++ prepare_repo_settings(p->repo);
++
write_pack_access_log(p, obj_offset);
+ /* PHASE 1: drill down to the innermost base object */
@@ packfile.c: void *unpack_entry(struct repository *r, struct packed_git *p, off_t obj_offset,
* before we are done using it.
*/
if (!external_base)
- add_delta_base_cache(p, base_obj_offset, base, base_size, type);
-+ add_delta_base_cache(p, base_obj_offset, base,
-+ base_size, delta_base_cache_limit,
++ add_delta_base_cache(p, base_obj_offset, base, base_size,
++ p->repo->settings.delta_base_cache_limit,
+ type);
free(delta_data);
free(external_base);
+
+ ## repo-settings.c ##
+@@
+ #include "repo-settings.h"
+ #include "repository.h"
+ #include "midx.h"
++#include "pack-objects.h"
+
+ static void repo_cfg_bool(struct repository *r, const char *key, int *dest,
+ int def)
+@@ repo-settings.c: void prepare_repo_settings(struct repository *r)
+ const char *strval;
+ int manyfiles;
+ int read_changed_paths;
++ unsigned long ulongval;
+
+ if (!r->gitdir)
+ BUG("Cannot add settings for uninitialized repository");
+@@ repo-settings.c: void prepare_repo_settings(struct repository *r)
+ * removed.
+ */
+ r->settings.command_requires_full_index = 1;
++
++ if (!repo_config_get_ulong(r, "core.deltabasecachelimit", &ulongval))
++ r->settings.delta_base_cache_limit = ulongval;
+ }
+
+ enum log_refs_config repo_settings_get_log_all_ref_updates(struct repository *repo)
+
+ ## repo-settings.h ##
+@@ repo-settings.h: struct repo_settings {
+
+ int core_multi_pack_index;
+ int warn_ambiguous_refs; /* lazily loaded via accessor */
++
++ size_t delta_base_cache_limit;
+ };
+ #define REPO_SETTINGS_INIT { \
+ .index_version = -1, \
+ .core_untracked_cache = UNTRACKED_CACHE_KEEP, \
+ .fetch_negotiation_algorithm = FETCH_NEGOTIATION_CONSECUTIVE, \
+ .warn_ambiguous_refs = -1, \
++ .delta_base_cache_limit = DEFAULT_DELTA_BASE_CACHE_LIMIT, \
+ }
+
+ void prepare_repo_settings(struct repository *r);
8: 7b6baa89ac ! 8: 30a52f192f config: make `packed_git_(limit|window_size)` non-global variables
@@ packfile.h: unsigned long repo_approximate_object_count(struct repository *r);
## repo-settings.c ##
@@ repo-settings.c: void prepare_repo_settings(struct repository *r)
- const char *strval;
- int manyfiles;
- int read_changed_paths;
-+ unsigned long longval;
- if (!r->gitdir)
- BUG("Cannot add settings for uninitialized repository");
-@@ repo-settings.c: void prepare_repo_settings(struct repository *r)
- * removed.
- */
- r->settings.command_requires_full_index = 1;
+ if (!repo_config_get_ulong(r, "core.deltabasecachelimit", &ulongval))
+ r->settings.delta_base_cache_limit = ulongval;
+
-+ if (!repo_config_get_ulong(r, "core.packedgitwindowsize", &longval)) {
++ if (!repo_config_get_ulong(r, "core.packedgitwindowsize", &ulongval)) {
+ int pgsz_x2 = getpagesize() * 2;
+
+ /* This value must be multiple of (pagesize * 2) */
-+ longval /= pgsz_x2;
-+ if (longval < 1)
-+ longval = 1;
-+ r->settings.packed_git_window_size = longval * pgsz_x2;
++ ulongval /= pgsz_x2;
++ if (ulongval < 1)
++ ulongval = 1;
++ r->settings.packed_git_window_size = ulongval * pgsz_x2;
+ }
+
-+ if (!repo_config_get_ulong(r, "core.packedgitlimit", &longval))
-+ r->settings.packed_git_limit = longval;
++ if (!repo_config_get_ulong(r, "core.packedgitlimit", &ulongval))
++ r->settings.packed_git_limit = ulongval;
}
enum log_refs_config repo_settings_get_log_all_ref_updates(struct repository *repo)
## repo-settings.h ##
@@ repo-settings.h: struct repo_settings {
-
- int core_multi_pack_index;
int warn_ambiguous_refs; /* lazily loaded via accessor */
-+
+
+ size_t delta_base_cache_limit;
+ size_t packed_git_window_size;
+ size_t packed_git_limit;
};
#define REPO_SETTINGS_INIT { \
.index_version = -1, \
- .core_untracked_cache = UNTRACKED_CACHE_KEEP, \
+@@ repo-settings.h: struct repo_settings {
.fetch_negotiation_algorithm = FETCH_NEGOTIATION_CONSECUTIVE, \
.warn_ambiguous_refs = -1, \
+ .delta_base_cache_limit = DEFAULT_DELTA_BASE_CACHE_LIMIT, \
+ .packed_git_window_size = DEFAULT_PACKED_GIT_WINDOW_SIZE, \
+ .packed_git_limit = DEFAULT_PACKED_GIT_LIMIT, \
}
9: a3667d87ec = 9: 2fe5d2506f midx: add repository to `multi_pack_index` struct
-: ---------- > 10: 05989c2e27 packfile.c: remove unnecessary prepare_packed_git() call-- 2.47.0