summaryrefslogtreecommitdiff
path: root/refs/refs-internal.h
blob: c7dded35f47e0c30131839b3378100e5a778476c (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
#ifndef REFS_REFS_INTERNAL_H
#define REFS_REFS_INTERNAL_H
 
/*
 * Data structures and functions for the internal use of the refs
 * module. Code outside of the refs module should use only the public
 * functions defined in "refs.h", and should *not* include this file.
 */
 
/*
 * Flag passed to lock_ref_sha1_basic() telling it to tolerate broken
 * refs (i.e., because the reference is about to be deleted anyway).
 */
#define REF_DELETING	0x02
 
/*
 * Used as a flag in ref_update::flags when a loose ref is being
 * pruned.
 */
#define REF_ISPRUNING	0x04
 
/*
 * Used as a flag in ref_update::flags when the reference should be
 * updated to new_sha1.
 */
#define REF_HAVE_NEW	0x08
 
/*
 * Used as a flag in ref_update::flags when old_sha1 should be
 * checked.
 */
#define REF_HAVE_OLD	0x10
 
/*
 * Used as a flag in ref_update::flags when the lockfile needs to be
 * committed.
 */
#define REF_NEEDS_COMMIT 0x20
 
/*
 * 0x40 is REF_FORCE_CREATE_REFLOG, so skip it if you're adding a
 * value to ref_update::flags
 */
 
/*
 * Return true iff refname is minimally safe. "Safe" here means that
 * deleting a loose reference by this name will not do any damage, for
 * example by causing a file that is not a reference to be deleted.
 * This function does not check that the reference name is legal; for
 * that, use check_refname_format().
 *
 * We consider a refname that starts with "refs/" to be safe as long
 * as any ".." components that it might contain do not escape "refs/".
 * Names that do not start with "refs/" are considered safe iff they
 * consist entirely of upper case characters and '_' (like "HEAD" and
 * "MERGE_HEAD" but not "config" or "FOO/BAR").
 */
int refname_is_safe(const char *refname);
 
enum peel_status {
	/* object was peeled successfully: */
	PEEL_PEELED = 0,
 
	/*
	 * object cannot be peeled because the named object (or an
	 * object referred to by a tag in the peel chain), does not
	 * exist.
	 */
	PEEL_INVALID = -1,
 
	/* object cannot be peeled because it is not a tag: */
	PEEL_NON_TAG = -2,
 
	/* ref_entry contains no peeled value because it is a symref: */
	PEEL_IS_SYMREF = -3,
 
	/*
	 * ref_entry cannot be peeled because it is broken (i.e., the
	 * symbolic reference cannot even be resolved to an object
	 * name):
	 */
	PEEL_BROKEN = -4
};
 
/*
 * Peel the named object; i.e., if the object is a tag, resolve the
 * tag recursively until a non-tag is found.  If successful, store the
 * result to sha1 and return PEEL_PEELED.  If the object is not a tag
 * or is not valid, return PEEL_NON_TAG or PEEL_INVALID, respectively,
 * and leave sha1 unchanged.
 */
enum peel_status peel_object(const unsigned char *name, unsigned char *sha1);
 
/*
 * Return 0 if a reference named refname could be created without
 * conflicting with the name of an existing reference. Otherwise,
 * return a negative value and write an explanation to err. If extras
 * is non-NULL, it is a list of additional refnames with which refname
 * is not allowed to conflict. If skip is non-NULL, ignore potential
 * conflicts with refs in skip (e.g., because they are scheduled for
 * deletion in the same operation). Behavior is undefined if the same
 * name is listed in both extras and skip.
 *
 * Two reference names conflict if one of them exactly matches the
 * leading components of the other; e.g., "foo/bar" conflicts with
 * both "foo" and with "foo/bar/baz" but not with "foo/bar" or
 * "foo/barbados".
 *
 * extras and skip must be sorted.
 */
int verify_refname_available(const char *newname,
			     struct string_list *extras,
			     struct string_list *skip,
			     struct strbuf *err);
 
/*
 * Copy the reflog message msg to buf, which has been allocated sufficiently
 * large, while cleaning up the whitespaces.  Especially, convert LF to space,
 * because reflog file is one line per entry.
 */
int copy_reflog_msg(char *buf, const char *msg);
 
int should_autocreate_reflog(const char *refname);
 
/**
 * Information needed for a single ref update. Set new_sha1 to the new
 * value or to null_sha1 to delete the ref. To check the old value
 * while the ref is locked, set (flags & REF_HAVE_OLD) and set
 * old_sha1 to the old value, or to null_sha1 to ensure the ref does
 * not exist before update.
 */
struct ref_update {
	/*
	 * If (flags & REF_HAVE_NEW), set the reference to this value:
	 */
	unsigned char new_sha1[20];
	/*
	 * If (flags & REF_HAVE_OLD), check that the reference
	 * previously had this value:
	 */
	unsigned char old_sha1[20];
	/*
	 * One or more of REF_HAVE_NEW, REF_HAVE_OLD, REF_NODEREF,
	 * REF_DELETING, and REF_ISPRUNING:
	 */
	unsigned int flags;
	struct ref_lock *lock;
	int type;
	char *msg;
	const char refname[FLEX_ARRAY];
};
 
/*
 * Transaction states.
 * OPEN:   The transaction is in a valid state and can accept new updates.
 *         An OPEN transaction can be committed.
 * CLOSED: A closed transaction is no longer active and no other operations
 *         than free can be used on it in this state.
 *         A transaction can either become closed by successfully committing
 *         an active transaction or if there is a failure while building
 *         the transaction thus rendering it failed/inactive.
 */
enum ref_transaction_state {
	REF_TRANSACTION_OPEN   = 0,
	REF_TRANSACTION_CLOSED = 1
};
 
/*
 * Data structure for holding a reference transaction, which can
 * consist of checks and updates to multiple references, carried out
 * as atomically as possible.  This structure is opaque to callers.
 */
struct ref_transaction {
	struct ref_update **updates;
	size_t alloc;
	size_t nr;
	enum ref_transaction_state state;
};
 
int files_log_ref_write(const char *refname, const unsigned char *old_sha1,
			const unsigned char *new_sha1, const char *msg,
			int flags, struct strbuf *err);
 
/*
 * Check for entries in extras that are within the specified
 * directory, where dirname is a reference directory name including
 * the trailing slash (e.g., "refs/heads/foo/"). Ignore any
 * conflicting references that are found in skip. If there is a
 * conflicting reference, return its name.
 *
 * extras and skip must be sorted lists of reference names. Either one
 * can be NULL, signifying the empty list.
 */
const char *find_descendant_ref(const char *dirname,
				const struct string_list *extras,
				const struct string_list *skip);
 
int rename_ref_available(const char *oldname, const char *newname);
 
#endif /* REFS_REFS_INTERNAL_H */