git/remote.h
Junio C Hamano 28f5d17611 remote.c: add command line option parser for "--force-with-lease"
Update "git push" and "git send-pack" to parse this commnd line
option.

The intended sematics is:

 * "--force-with-lease" alone, without specifying the details, will
   protect _all_ remote refs that are going to be updated by
   requiring their current value to be the same as some reasonable
   default, unless otherwise specified;

 * "--force-with-lease=refname", without specifying the expected
   value, will protect that refname, if it is going to be updated,
   by requiring its current value to be the same as some reasonable
   default.

 * "--force-with-lease=refname:value" will protect that refname, if
   it is going to be updated, by requiring its current value to be
   the same as the specified value; and

 * "--no-force-with-lease" will cancel all the previous --force-with-lease on the
   command line.

For now, "some reasonable default" is tentatively defined as "the
value of the remote-tracking branch we have for the ref of the
remote being updated", and it is an error if we do not have such a
remote-tracking branch.  But this is known to be fragile, its use is
not yet recommended, and hopefully we will find more reasonable
default as we gain experience with this feature.  The manual marks
the feature as experimental unless the expected value is specified
explicitly for this reason.

Because the command line options are parsed _before_ we know which
remote we are pushing to, there needs further processing to the
parsed data after we instantiate the transport object to:

 * expand "refname" given by the user to a full refname to be
   matched with the list of "struct ref" used in match_push_refs()
   and set_ref_status_for_push(); and

 * learning the actual local ref that is the remote-tracking branch
   for the specified remote ref.

Further, some processing need to be deferred until we find the set
of remote refs and match_push_refs() returns in order to find the
ones that need to be checked after explicit ones have been processed
for "--force-with-lease" (no specific details).

These post-processing will be the topic of the next patch.

This option was originally called "cas" (for "compare and swap"),
the name which nobody liked because it was too technical.  The
second attempt called it "lockref" (because it is conceptually like
pushing after taking a lock) but the word "lock" was hated because
it implied that it may reject push by others, which is not the way
this option works.  This round calls it "force-with-lease".  You
assume you took the lease on the ref when you fetched to decide what
the rebased history should be, and you can push back only if the
lease has not been broken.

Signed-off-by: Junio C Hamano <gitster@pobox.com>
2013-07-22 22:02:55 -07:00

252 lines
6.2 KiB
C

#ifndef REMOTE_H
#define REMOTE_H
#include "parse-options.h"
enum {
REMOTE_CONFIG,
REMOTE_REMOTES,
REMOTE_BRANCHES
};
struct remote {
const char *name;
int origin;
const char *foreign_vcs;
const char **url;
int url_nr;
int url_alloc;
const char **pushurl;
int pushurl_nr;
int pushurl_alloc;
const char **push_refspec;
struct refspec *push;
int push_refspec_nr;
int push_refspec_alloc;
const char **fetch_refspec;
struct refspec *fetch;
int fetch_refspec_nr;
int fetch_refspec_alloc;
/*
* -1 to never fetch tags
* 0 to auto-follow tags on heuristic (default)
* 1 to always auto-follow tags
* 2 to always fetch tags
*/
int fetch_tags;
int skip_default_update;
int mirror;
const char *receivepack;
const char *uploadpack;
/*
* for curl remotes only
*/
char *http_proxy;
};
struct remote *remote_get(const char *name);
struct remote *pushremote_get(const char *name);
int remote_is_configured(const char *name);
typedef int each_remote_fn(struct remote *remote, void *priv);
int for_each_remote(each_remote_fn fn, void *priv);
int remote_has_url(struct remote *remote, const char *url);
struct refspec {
unsigned force : 1;
unsigned pattern : 1;
unsigned matching : 1;
unsigned exact_sha1 : 1;
char *src;
char *dst;
};
extern const struct refspec *tag_refspec;
struct ref {
struct ref *next;
unsigned char old_sha1[20];
unsigned char new_sha1[20];
char *symref;
unsigned int
force:1,
forced_update:1,
deletion:1,
matched:1;
/*
* Order is important here, as we write to FETCH_HEAD
* in numeric order. And the default NOT_FOR_MERGE
* should be 0, so that xcalloc'd structures get it
* by default.
*/
enum {
FETCH_HEAD_MERGE = -1,
FETCH_HEAD_NOT_FOR_MERGE = 0,
FETCH_HEAD_IGNORE = 1
} fetch_head_status;
enum {
REF_STATUS_NONE = 0,
REF_STATUS_OK,
REF_STATUS_REJECT_NONFASTFORWARD,
REF_STATUS_REJECT_ALREADY_EXISTS,
REF_STATUS_REJECT_NODELETE,
REF_STATUS_REJECT_FETCH_FIRST,
REF_STATUS_REJECT_NEEDS_FORCE,
REF_STATUS_UPTODATE,
REF_STATUS_REMOTE_REJECT,
REF_STATUS_EXPECTING_REPORT
} status;
char *remote_status;
struct ref *peer_ref; /* when renaming */
char name[FLEX_ARRAY]; /* more */
};
#define REF_NORMAL (1u << 0)
#define REF_HEADS (1u << 1)
#define REF_TAGS (1u << 2)
extern struct ref *find_ref_by_name(const struct ref *list, const char *name);
struct ref *alloc_ref(const char *name);
struct ref *copy_ref(const struct ref *ref);
struct ref *copy_ref_list(const struct ref *ref);
void sort_ref_list(struct ref **, int (*cmp)(const void *, const void *));
int ref_compare_name(const void *, const void *);
int check_ref_type(const struct ref *ref, int flags);
/*
* Frees the entire list and peers of elements.
*/
void free_refs(struct ref *ref);
struct extra_have_objects {
int nr, alloc;
unsigned char (*array)[20];
};
extern struct ref **get_remote_heads(int in, char *src_buf, size_t src_len,
struct ref **list, unsigned int flags,
struct extra_have_objects *);
int resolve_remote_symref(struct ref *ref, struct ref *list);
int ref_newer(const unsigned char *new_sha1, const unsigned char *old_sha1);
/*
* Removes and frees any duplicate refs in the map.
*/
void ref_remove_duplicates(struct ref *ref_map);
int valid_fetch_refspec(const char *refspec);
struct refspec *parse_fetch_refspec(int nr_refspec, const char **refspec);
void free_refspec(int nr_refspec, struct refspec *refspec);
char *apply_refspecs(struct refspec *refspecs, int nr_refspec,
const char *name);
int match_push_refs(struct ref *src, struct ref **dst,
int nr_refspec, const char **refspec, int all);
void set_ref_status_for_push(struct ref *remote_refs, int send_mirror,
int force_update);
/*
* Given a list of the remote refs and the specification of things to
* fetch, makes a (separate) list of the refs to fetch and the local
* refs to store into.
*
* *tail is the pointer to the tail pointer of the list of results
* beforehand, and will be set to the tail pointer of the list of
* results afterward.
*
* missing_ok is usually false, but when we are adding branch.$name.merge
* it is Ok if the branch is not at the remote anymore.
*/
int get_fetch_map(const struct ref *remote_refs, const struct refspec *refspec,
struct ref ***tail, int missing_ok);
struct ref *get_remote_ref(const struct ref *remote_refs, const char *name);
/*
* For the given remote, reads the refspec's src and sets the other fields.
*/
int remote_find_tracking(struct remote *remote, struct refspec *refspec);
struct branch {
const char *name;
const char *refname;
const char *remote_name;
struct remote *remote;
const char **merge_name;
struct refspec **merge;
int merge_nr;
int merge_alloc;
};
struct branch *branch_get(const char *name);
int branch_has_merge_config(struct branch *branch);
int branch_merge_matches(struct branch *, int n, const char *);
/* Flags to match_refs. */
enum match_refs_flags {
MATCH_REFS_NONE = 0,
MATCH_REFS_ALL = (1 << 0),
MATCH_REFS_MIRROR = (1 << 1),
MATCH_REFS_PRUNE = (1 << 2),
MATCH_REFS_FOLLOW_TAGS = (1 << 3)
};
/* Reporting of tracking info */
int stat_tracking_info(struct branch *branch, int *num_ours, int *num_theirs);
int format_tracking_info(struct branch *branch, struct strbuf *sb);
struct ref *get_local_heads(void);
/*
* Find refs from a list which are likely to be pointed to by the given HEAD
* ref. If 'all' is false, returns the most likely ref; otherwise, returns a
* list of all candidate refs. If no match is found (or 'head' is NULL),
* returns NULL. All returns are newly allocated and should be freed.
*/
struct ref *guess_remote_head(const struct ref *head,
const struct ref *refs,
int all);
/* Return refs which no longer exist on remote */
struct ref *get_stale_heads(struct refspec *refs, int ref_count, struct ref *fetch_map);
/*
* Compare-and-swap
*/
#define CAS_OPT_NAME "force-with-lease"
struct push_cas_option {
unsigned use_tracking_for_rest:1;
struct push_cas {
unsigned char expect[20];
unsigned use_tracking:1;
char *refname;
} *entry;
int nr;
int alloc;
};
extern int parseopt_push_cas_option(const struct option *, const char *arg, int unset);
extern int parse_push_cas_option(struct push_cas_option *, const char *arg, int unset);
extern void clear_cas_option(struct push_cas_option *);
#endif