mirror of
https://github.com/git/git.git
synced 2024-05-18 03:06:17 +02:00
7199203937
In a couple of places, we pop objects off an object array `foo` by
decreasing `foo.nr`. We access `foo.nr` in many places, but most if not
all other times we do so read-only, e.g., as we iterate over the array.
But when we change `foo.nr` behind the array's back, it feels a bit
nasty and looks like it might leak memory.
Leaks happen if the popped element has an allocated `name` or `path`.
At the moment, that is not the case. Still, 1) the object array might
gain more fields that want to be freed, 2) a code path where we pop
might start using names or paths, 3) one of these code paths might be
copied to somewhere where we do, and 4) using a dedicated function for
popping is conceptually cleaner.
Introduce and use `object_array_pop()` instead. Release memory in the
new function. Document that popping an object leaves the associated
elements in limbo.
The converted places were identified by grepping for "\.nr\>" and
looking for "--".
Make the new function return NULL on an empty array. This is consistent
with `pop_commit()` and allows the following:
while ((o = object_array_pop(&foo)) != NULL) {
// do something
}
But as noted above, we don't need to go out of our way to avoid reading
`foo.nr`. This is probably more readable:
while (foo.nr) {
... o = object_array_pop(&foo);
// do something
}
The name of `object_array_pop()` does not quite align with
`add_object_array()`. That is unfortunate. On the other hand, it matches
`object_array_clear()`. Arguably it's `add_...` that is the odd one out,
since it reads like it's used to "add" an "object array". For that
reason, side with `object_array_clear()`.
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>
152 lines
4.8 KiB
C
152 lines
4.8 KiB
C
#ifndef OBJECT_H
|
|
#define OBJECT_H
|
|
|
|
struct object_list {
|
|
struct object *item;
|
|
struct object_list *next;
|
|
};
|
|
|
|
struct object_array {
|
|
unsigned int nr;
|
|
unsigned int alloc;
|
|
struct object_array_entry {
|
|
struct object *item;
|
|
/*
|
|
* name or NULL. If non-NULL, the memory pointed to
|
|
* is owned by this object *except* if it points at
|
|
* object_array_slopbuf, which is a static copy of the
|
|
* empty string.
|
|
*/
|
|
char *name;
|
|
char *path;
|
|
unsigned mode;
|
|
} *objects;
|
|
};
|
|
|
|
#define OBJECT_ARRAY_INIT { 0, 0, NULL }
|
|
|
|
#define TYPE_BITS 3
|
|
/*
|
|
* object flag allocation:
|
|
* revision.h: 0---------10 26
|
|
* fetch-pack.c: 0---5
|
|
* walker.c: 0-2
|
|
* upload-pack.c: 4 11----------------19
|
|
* builtin/blame.c: 12-13
|
|
* bisect.c: 16
|
|
* bundle.c: 16
|
|
* http-push.c: 16-----19
|
|
* commit.c: 16-----19
|
|
* sha1_name.c: 20
|
|
* builtin/fsck.c: 0--3
|
|
*/
|
|
#define FLAG_BITS 27
|
|
|
|
/*
|
|
* The object type is stored in 3 bits.
|
|
*/
|
|
struct object {
|
|
unsigned parsed : 1;
|
|
unsigned type : TYPE_BITS;
|
|
unsigned flags : FLAG_BITS;
|
|
struct object_id oid;
|
|
};
|
|
|
|
extern const char *typename(unsigned int type);
|
|
extern int type_from_string_gently(const char *str, ssize_t, int gentle);
|
|
#define type_from_string(str) type_from_string_gently(str, -1, 0)
|
|
|
|
/*
|
|
* Return the current number of buckets in the object hashmap.
|
|
*/
|
|
extern unsigned int get_max_object_index(void);
|
|
|
|
/*
|
|
* Return the object from the specified bucket in the object hashmap.
|
|
*/
|
|
extern struct object *get_indexed_object(unsigned int);
|
|
|
|
/*
|
|
* This can be used to see if we have heard of the object before, but
|
|
* it can return "yes we have, and here is a half-initialised object"
|
|
* for an object that we haven't loaded/parsed yet.
|
|
*
|
|
* When parsing a commit to create an in-core commit object, its
|
|
* parents list holds commit objects that represent its parents, but
|
|
* they are expected to be lazily initialized and do not know what
|
|
* their trees or parents are yet. When this function returns such a
|
|
* half-initialised objects, the caller is expected to initialize them
|
|
* by calling parse_object() on them.
|
|
*/
|
|
struct object *lookup_object(const unsigned char *sha1);
|
|
|
|
extern void *create_object(const unsigned char *sha1, void *obj);
|
|
|
|
void *object_as_type(struct object *obj, enum object_type type, int quiet);
|
|
|
|
/*
|
|
* Returns the object, having parsed it to find out what it is.
|
|
*
|
|
* Returns NULL if the object is missing or corrupt.
|
|
*/
|
|
struct object *parse_object(const struct object_id *oid);
|
|
|
|
/*
|
|
* Like parse_object, but will die() instead of returning NULL. If the
|
|
* "name" parameter is not NULL, it is included in the error message
|
|
* (otherwise, the hex object ID is given).
|
|
*/
|
|
struct object *parse_object_or_die(const struct object_id *oid, const char *name);
|
|
|
|
/* Given the result of read_sha1_file(), returns the object after
|
|
* parsing it. eaten_p indicates if the object has a borrowed copy
|
|
* of buffer and the caller should not free() it.
|
|
*/
|
|
struct object *parse_object_buffer(const struct object_id *oid, enum object_type type, unsigned long size, void *buffer, int *eaten_p);
|
|
|
|
/** Returns the object, with potentially excess memory allocated. **/
|
|
struct object *lookup_unknown_object(const unsigned char *sha1);
|
|
|
|
struct object_list *object_list_insert(struct object *item,
|
|
struct object_list **list_p);
|
|
|
|
int object_list_contains(struct object_list *list, struct object *obj);
|
|
|
|
/* Object array handling .. */
|
|
void add_object_array(struct object *obj, const char *name, struct object_array *array);
|
|
void add_object_array_with_path(struct object *obj, const char *name, struct object_array *array, unsigned mode, const char *path);
|
|
|
|
/*
|
|
* Returns NULL if the array is empty. Otherwise, returns the last object
|
|
* after removing its entry from the array. Other resources associated
|
|
* with that object are left in an unspecified state and should not be
|
|
* examined.
|
|
*/
|
|
struct object *object_array_pop(struct object_array *array);
|
|
|
|
typedef int (*object_array_each_func_t)(struct object_array_entry *, void *);
|
|
|
|
/*
|
|
* Apply want to each entry in array, retaining only the entries for
|
|
* which the function returns true. Preserve the order of the entries
|
|
* that are retained.
|
|
*/
|
|
void object_array_filter(struct object_array *array,
|
|
object_array_each_func_t want, void *cb_data);
|
|
|
|
/*
|
|
* Remove from array all but the first entry with a given name.
|
|
* Warning: this function uses an O(N^2) algorithm.
|
|
*/
|
|
void object_array_remove_duplicates(struct object_array *array);
|
|
|
|
/*
|
|
* Remove any objects from the array, freeing all used memory; afterwards
|
|
* the array is ready to store more objects with add_object_array().
|
|
*/
|
|
void object_array_clear(struct object_array *array);
|
|
|
|
void clear_object_flags(unsigned flags);
|
|
|
|
#endif /* OBJECT_H */
|