summaryrefslogtreecommitdiff
path: root/sha1_name.c
diff options
context:
space:
mode:
Diffstat (limited to 'sha1_name.c')
-rw-r--r--sha1_name.c494
1 files changed, 366 insertions, 128 deletions
diff --git a/sha1_name.c b/sha1_name.c
index 5d81ea0..95003c7 100644
--- a/sha1_name.c
+++ b/sha1_name.c
@@ -9,14 +9,82 @@
static int get_sha1_oneline(const char *, unsigned char *, struct commit_list *);
-static int find_short_object_filename(int len, const char *name, unsigned char *sha1)
+typedef int (*disambiguate_hint_fn)(const unsigned char *, void *);
+
+struct disambiguate_state {
+ disambiguate_hint_fn fn;
+ void *cb_data;
+ unsigned char candidate[20];
+ unsigned candidate_exists:1;
+ unsigned candidate_checked:1;
+ unsigned candidate_ok:1;
+ unsigned disambiguate_fn_used:1;
+ unsigned ambiguous:1;
+ unsigned always_call_fn:1;
+};
+
+static void update_candidates(struct disambiguate_state *ds, const unsigned char *current)
+{
+ if (ds->always_call_fn) {
+ ds->ambiguous = ds->fn(current, ds->cb_data) ? 1 : 0;
+ return;
+ }
+ if (!ds->candidate_exists) {
+ /* this is the first candidate */
+ hashcpy(ds->candidate, current);
+ ds->candidate_exists = 1;
+ return;
+ } else if (!hashcmp(ds->candidate, current)) {
+ /* the same as what we already have seen */
+ return;
+ }
+
+ if (!ds->fn) {
+ /* cannot disambiguate between ds->candidate and current */
+ ds->ambiguous = 1;
+ return;
+ }
+
+ if (!ds->candidate_checked) {
+ ds->candidate_ok = ds->fn(ds->candidate, ds->cb_data);
+ ds->disambiguate_fn_used = 1;
+ ds->candidate_checked = 1;
+ }
+
+ if (!ds->candidate_ok) {
+ /* discard the candidate; we know it does not satisify fn */
+ hashcpy(ds->candidate, current);
+ ds->candidate_checked = 0;
+ return;
+ }
+
+ /* if we reach this point, we know ds->candidate satisfies fn */
+ if (ds->fn(current, ds->cb_data)) {
+ /*
+ * if both current and candidate satisfy fn, we cannot
+ * disambiguate.
+ */
+ ds->candidate_ok = 0;
+ ds->ambiguous = 1;
+ }
+
+ /* otherwise, current can be discarded and candidate is still good */
+}
+
+static void find_short_object_filename(int len, const char *hex_pfx, struct disambiguate_state *ds)
{
struct alternate_object_database *alt;
char hex[40];
- int found = 0;
static struct alternate_object_database *fakeent;
if (!fakeent) {
+ /*
+ * Create a "fake" alternate object database that
+ * points to our own object database, to make it
+ * easier to get a temporary working space in
+ * alt->name/alt->base while iterating over the
+ * object databases including our own.
+ */
const char *objdir = get_object_directory();
int objdir_len = strlen(objdir);
int entlen = objdir_len + 43;
@@ -27,33 +95,28 @@ static int find_short_object_filename(int len, const char *name, unsigned char *
}
fakeent->next = alt_odb_list;
- sprintf(hex, "%.2s", name);
- for (alt = fakeent; alt && found < 2; alt = alt->next) {
+ sprintf(hex, "%.2s", hex_pfx);
+ for (alt = fakeent; alt && !ds->ambiguous; alt = alt->next) {
struct dirent *de;
DIR *dir;
- sprintf(alt->name, "%.2s/", name);
+ sprintf(alt->name, "%.2s/", hex_pfx);
dir = opendir(alt->base);
if (!dir)
continue;
- while ((de = readdir(dir)) != NULL) {
+
+ while (!ds->ambiguous && (de = readdir(dir)) != NULL) {
+ unsigned char sha1[20];
+
if (strlen(de->d_name) != 38)
continue;
- if (memcmp(de->d_name, name + 2, len - 2))
+ if (memcmp(de->d_name, hex_pfx + 2, len - 2))
continue;
- if (!found) {
- memcpy(hex + 2, de->d_name, 38);
- found++;
- }
- else if (memcmp(hex + 2, de->d_name, 38)) {
- found = 2;
- break;
- }
+ memcpy(hex + 2, de->d_name, 38);
+ if (!get_sha1_hex(hex, sha1))
+ update_candidates(ds, sha1);
}
closedir(dir);
}
- if (found == 1)
- return get_sha1_hex(hex, sha1) == 0;
- return found;
}
static int match_sha(unsigned len, const unsigned char *a, const unsigned char *b)
@@ -71,103 +134,157 @@ static int match_sha(unsigned len, const unsigned char *a, const unsigned char *
return 1;
}
-static int find_short_packed_object(int len, const unsigned char *match, unsigned char *sha1)
+static void unique_in_pack(int len,
+ const unsigned char *bin_pfx,
+ struct packed_git *p,
+ struct disambiguate_state *ds)
{
- struct packed_git *p;
- const unsigned char *found_sha1 = NULL;
- int found = 0;
-
- prepare_packed_git();
- for (p = packed_git; p && found < 2; p = p->next) {
- uint32_t num, last;
- uint32_t first = 0;
- open_pack_index(p);
- num = p->num_objects;
- last = num;
- while (first < last) {
- uint32_t mid = (first + last) / 2;
- const unsigned char *now;
- int cmp;
-
- now = nth_packed_object_sha1(p, mid);
- cmp = hashcmp(match, now);
- if (!cmp) {
- first = mid;
- break;
- }
- if (cmp > 0) {
- first = mid+1;
- continue;
- }
- last = mid;
+ uint32_t num, last, i, first = 0;
+ const unsigned char *current = NULL;
+
+ open_pack_index(p);
+ num = p->num_objects;
+ last = num;
+ while (first < last) {
+ uint32_t mid = (first + last) / 2;
+ const unsigned char *current;
+ int cmp;
+
+ current = nth_packed_object_sha1(p, mid);
+ cmp = hashcmp(bin_pfx, current);
+ if (!cmp) {
+ first = mid;
+ break;
}
- if (first < num) {
- const unsigned char *now, *next;
- now = nth_packed_object_sha1(p, first);
- if (match_sha(len, match, now)) {
- next = nth_packed_object_sha1(p, first+1);
- if (!next|| !match_sha(len, match, next)) {
- /* unique within this pack */
- if (!found) {
- found_sha1 = now;
- found++;
- }
- else if (hashcmp(found_sha1, now)) {
- found = 2;
- break;
- }
- }
- else {
- /* not even unique within this pack */
- found = 2;
- break;
- }
- }
+ if (cmp > 0) {
+ first = mid+1;
+ continue;
}
+ last = mid;
+ }
+
+ /*
+ * At this point, "first" is the location of the lowest object
+ * with an object name that could match "bin_pfx". See if we have
+ * 0, 1 or more objects that actually match(es).
+ */
+ for (i = first; i < num && !ds->ambiguous; i++) {
+ current = nth_packed_object_sha1(p, i);
+ if (!match_sha(len, bin_pfx, current))
+ break;
+ update_candidates(ds, current);
}
- if (found == 1)
- hashcpy(sha1, found_sha1);
- return found;
+}
+
+static void find_short_packed_object(int len, const unsigned char *bin_pfx,
+ struct disambiguate_state *ds)
+{
+ struct packed_git *p;
+
+ prepare_packed_git();
+ for (p = packed_git; p && !ds->ambiguous; p = p->next)
+ unique_in_pack(len, bin_pfx, p, ds);
}
#define SHORT_NAME_NOT_FOUND (-1)
#define SHORT_NAME_AMBIGUOUS (-2)
-static int find_unique_short_object(int len, char *canonical,
- unsigned char *res, unsigned char *sha1)
+static int finish_object_disambiguation(struct disambiguate_state *ds,
+ unsigned char *sha1)
{
- int has_unpacked, has_packed;
- unsigned char unpacked_sha1[20], packed_sha1[20];
+ if (ds->ambiguous)
+ return SHORT_NAME_AMBIGUOUS;
- prepare_alt_odb();
- has_unpacked = find_short_object_filename(len, canonical, unpacked_sha1);
- has_packed = find_short_packed_object(len, res, packed_sha1);
- if (!has_unpacked && !has_packed)
+ if (!ds->candidate_exists)
return SHORT_NAME_NOT_FOUND;
- if (1 < has_unpacked || 1 < has_packed)
+
+ if (!ds->candidate_checked)
+ /*
+ * If this is the only candidate, there is no point
+ * calling the disambiguation hint callback.
+ *
+ * On the other hand, if the current candidate
+ * replaced an earlier candidate that did _not_ pass
+ * the disambiguation hint callback, then we do have
+ * more than one objects that match the short name
+ * given, so we should make sure this one matches;
+ * otherwise, if we discovered this one and the one
+ * that we previously discarded in the reverse order,
+ * we would end up showing different results in the
+ * same repository!
+ */
+ ds->candidate_ok = (!ds->disambiguate_fn_used ||
+ ds->fn(ds->candidate, ds->cb_data));
+
+ if (!ds->candidate_ok)
return SHORT_NAME_AMBIGUOUS;
- if (has_unpacked != has_packed) {
- hashcpy(sha1, (has_packed ? packed_sha1 : unpacked_sha1));
+
+ hashcpy(sha1, ds->candidate);
+ return 0;
+}
+
+static int disambiguate_commit_only(const unsigned char *sha1, void *cb_data_unused)
+{
+ int kind = sha1_object_info(sha1, NULL);
+ return kind == OBJ_COMMIT;
+}
+
+static int disambiguate_committish_only(const unsigned char *sha1, void *cb_data_unused)
+{
+ struct object *obj;
+ int kind;
+
+ kind = sha1_object_info(sha1, NULL);
+ if (kind == OBJ_COMMIT)
+ return 1;
+ if (kind != OBJ_TAG)
return 0;
- }
- /* Both have unique ones -- do they match? */
- if (hashcmp(packed_sha1, unpacked_sha1))
- return SHORT_NAME_AMBIGUOUS;
- hashcpy(sha1, packed_sha1);
+
+ /* We need to do this the hard way... */
+ obj = deref_tag(lookup_object(sha1), NULL, 0);
+ if (obj && obj->type == OBJ_COMMIT)
+ return 1;
return 0;
}
-static int get_short_sha1(const char *name, int len, unsigned char *sha1,
- int quietly)
+static int disambiguate_tree_only(const unsigned char *sha1, void *cb_data_unused)
{
- int i, status;
- char canonical[40];
- unsigned char res[20];
+ int kind = sha1_object_info(sha1, NULL);
+ return kind == OBJ_TREE;
+}
- if (len < MINIMUM_ABBREV || len > 40)
- return -1;
- hashclr(res);
- memset(canonical, 'x', 40);
+static int disambiguate_treeish_only(const unsigned char *sha1, void *cb_data_unused)
+{
+ struct object *obj;
+ int kind;
+
+ kind = sha1_object_info(sha1, NULL);
+ if (kind == OBJ_TREE || kind == OBJ_COMMIT)
+ return 1;
+ if (kind != OBJ_TAG)
+ return 0;
+
+ /* We need to do this the hard way... */
+ obj = deref_tag(lookup_object(sha1), NULL, 0);
+ if (obj && (obj->type == OBJ_TREE || obj->type == OBJ_COMMIT))
+ return 1;
+ return 0;
+}
+
+static int disambiguate_blob_only(const unsigned char *sha1, void *cb_data_unused)
+{
+ int kind = sha1_object_info(sha1, NULL);
+ return kind == OBJ_BLOB;
+}
+
+static int prepare_prefixes(const char *name, int len,
+ unsigned char *bin_pfx,
+ char *hex_pfx)
+{
+ int i;
+
+ hashclr(bin_pfx);
+ memset(hex_pfx, 'x', 40);
for (i = 0; i < len ;i++) {
unsigned char c = name[i];
unsigned char val;
@@ -181,18 +298,76 @@ static int get_short_sha1(const char *name, int len, unsigned char *sha1,
}
else
return -1;
- canonical[i] = c;
+ hex_pfx[i] = c;
if (!(i & 1))
val <<= 4;
- res[i >> 1] |= val;
+ bin_pfx[i >> 1] |= val;
}
+ return 0;
+}
+
+static int get_short_sha1(const char *name, int len, unsigned char *sha1,
+ unsigned flags)
+{
+ int status;
+ char hex_pfx[40];
+ unsigned char bin_pfx[20];
+ struct disambiguate_state ds;
+ int quietly = !!(flags & GET_SHA1_QUIETLY);
+
+ if (len < MINIMUM_ABBREV || len > 40)
+ return -1;
+ if (prepare_prefixes(name, len, bin_pfx, hex_pfx) < 0)
+ return -1;
+
+ prepare_alt_odb();
+
+ memset(&ds, 0, sizeof(ds));
+ if (flags & GET_SHA1_COMMIT)
+ ds.fn = disambiguate_commit_only;
+ else if (flags & GET_SHA1_COMMITTISH)
+ ds.fn = disambiguate_committish_only;
+ else if (flags & GET_SHA1_TREE)
+ ds.fn = disambiguate_tree_only;
+ else if (flags & GET_SHA1_TREEISH)
+ ds.fn = disambiguate_treeish_only;
+ else if (flags & GET_SHA1_BLOB)
+ ds.fn = disambiguate_blob_only;
+
+ find_short_object_filename(len, hex_pfx, &ds);
+ find_short_packed_object(len, bin_pfx, &ds);
+ status = finish_object_disambiguation(&ds, sha1);
- status = find_unique_short_object(i, canonical, res, sha1);
if (!quietly && (status == SHORT_NAME_AMBIGUOUS))
- return error("short SHA1 %.*s is ambiguous.", len, canonical);
+ return error("short SHA1 %.*s is ambiguous.", len, hex_pfx);
return status;
}
+
+int for_each_abbrev(const char *prefix, each_abbrev_fn fn, void *cb_data)
+{
+ char hex_pfx[40];
+ unsigned char bin_pfx[20];
+ struct disambiguate_state ds;
+ int len = strlen(prefix);
+
+ if (len < MINIMUM_ABBREV || len > 40)
+ return -1;
+ if (prepare_prefixes(prefix, len, bin_pfx, hex_pfx) < 0)
+ return -1;
+
+ prepare_alt_odb();
+
+ memset(&ds, 0, sizeof(ds));
+ ds.always_call_fn = 1;
+ ds.cb_data = cb_data;
+ ds.fn = fn;
+
+ find_short_object_filename(len, hex_pfx, &ds);
+ find_short_packed_object(len, bin_pfx, &ds);
+ return ds.ambiguous;
+}
+
const char *find_unique_abbrev(const unsigned char *sha1, int len)
{
int status, exists;
@@ -204,7 +379,7 @@ const char *find_unique_abbrev(const unsigned char *sha1, int len)
return hex;
while (len < 40) {
unsigned char sha1_ret[20];
- status = get_short_sha1(hex, len, sha1_ret, 1);
+ status = get_short_sha1(hex, len, sha1_ret, GET_SHA1_QUIETLY);
if (exists
? !status
: status == SHORT_NAME_NOT_FOUND) {
@@ -255,7 +430,7 @@ static inline int upstream_mark(const char *string, int len)
return 0;
}
-static int get_sha1_1(const char *name, int len, unsigned char *sha1);
+static int get_sha1_1(const char *name, int len, unsigned char *sha1, unsigned lookup_flags);
static int get_sha1_basic(const char *str, int len, unsigned char *sha1)
{
@@ -292,7 +467,7 @@ static int get_sha1_basic(const char *str, int len, unsigned char *sha1)
ret = interpret_branch_name(str+at, &buf);
if (ret > 0) {
/* substitute this branch name and restart */
- return get_sha1_1(buf.buf, buf.len, sha1);
+ return get_sha1_1(buf.buf, buf.len, sha1, 0);
} else if (ret == 0) {
return -1;
}
@@ -362,7 +537,7 @@ static int get_parent(const char *name, int len,
unsigned char *result, int idx)
{
unsigned char sha1[20];
- int ret = get_sha1_1(name, len, sha1);
+ int ret = get_sha1_1(name, len, sha1, GET_SHA1_COMMITTISH);
struct commit *commit;
struct commit_list *p;
@@ -395,7 +570,7 @@ static int get_nth_ancestor(const char *name, int len,
struct commit *commit;
int ret;
- ret = get_sha1_1(name, len, sha1);
+ ret = get_sha1_1(name, len, sha1, GET_SHA1_COMMITTISH);
if (ret)
return ret;
commit = lookup_commit_reference(sha1);
@@ -441,6 +616,7 @@ static int peel_onion(const char *name, int len, unsigned char *sha1)
unsigned char outer[20];
const char *sp;
unsigned int expected_type = 0;
+ unsigned lookup_flags = 0;
struct object *o;
/*
@@ -476,7 +652,10 @@ static int peel_onion(const char *name, int len, unsigned char *sha1)
else
return -1;
- if (get_sha1_1(name, sp - name - 2, outer))
+ if (expected_type == OBJ_COMMIT)
+ lookup_flags = GET_SHA1_COMMITTISH;
+
+ if (get_sha1_1(name, sp - name - 2, outer, lookup_flags))
return -1;
o = parse_object(outer);
@@ -525,6 +704,7 @@ static int peel_onion(const char *name, int len, unsigned char *sha1)
static int get_describe_name(const char *name, int len, unsigned char *sha1)
{
const char *cp;
+ unsigned flags = GET_SHA1_QUIETLY | GET_SHA1_COMMIT;
for (cp = name + len - 1; name + 2 <= cp; cp--) {
char ch = *cp;
@@ -535,14 +715,14 @@ static int get_describe_name(const char *name, int len, unsigned char *sha1)
if (ch == 'g' && cp[-1] == '-') {
cp++;
len -= cp - name;
- return get_short_sha1(cp, len, sha1, 1);
+ return get_short_sha1(cp, len, sha1, flags);
}
}
}
return -1;
}
-static int get_sha1_1(const char *name, int len, unsigned char *sha1)
+static int get_sha1_1(const char *name, int len, unsigned char *sha1, unsigned lookup_flags)
{
int ret, has_suffix;
const char *cp;
@@ -587,7 +767,7 @@ static int get_sha1_1(const char *name, int len, unsigned char *sha1)
if (!ret)
return 0;
- return get_short_sha1(name, len, sha1, 0);
+ return get_short_sha1(name, len, sha1, lookup_flags);
}
/*
@@ -769,7 +949,7 @@ int get_sha1_mb(const char *name, unsigned char *sha1)
struct strbuf sb;
strbuf_init(&sb, dots - name);
strbuf_add(&sb, name, dots - name);
- st = get_sha1(sb.buf, sha1_tmp);
+ st = get_sha1_committish(sb.buf, sha1_tmp);
strbuf_release(&sb);
}
if (st)
@@ -778,7 +958,7 @@ int get_sha1_mb(const char *name, unsigned char *sha1)
if (!one)
return -1;
- if (get_sha1(dots[3] ? (dots + 3) : "HEAD", sha1_tmp))
+ if (get_sha1_committish(dots[3] ? (dots + 3) : "HEAD", sha1_tmp))
return -1;
two = lookup_commit_reference_gently(sha1_tmp, 0);
if (!two)
@@ -905,7 +1085,52 @@ int strbuf_check_branch_ref(struct strbuf *sb, const char *name)
int get_sha1(const char *name, unsigned char *sha1)
{
struct object_context unused;
- return get_sha1_with_context(name, sha1, &unused);
+ return get_sha1_with_context(name, 0, sha1, &unused);
+}
+
+/*
+ * Many callers know that the user meant to name a committish by
+ * syntactical positions where the object name appears. Calling this
+ * function allows the machinery to disambiguate shorter-than-unique
+ * abbreviated object names between committish and others.
+ *
+ * Note that this does NOT error out when the named object is not a
+ * committish. It is merely to give a hint to the disambiguation
+ * machinery.
+ */
+int get_sha1_committish(const char *name, unsigned char *sha1)
+{
+ struct object_context unused;
+ return get_sha1_with_context(name, GET_SHA1_COMMITTISH,
+ sha1, &unused);
+}
+
+int get_sha1_treeish(const char *name, unsigned char *sha1)
+{
+ struct object_context unused;
+ return get_sha1_with_context(name, GET_SHA1_TREEISH,
+ sha1, &unused);
+}
+
+int get_sha1_commit(const char *name, unsigned char *sha1)
+{
+ struct object_context unused;
+ return get_sha1_with_context(name, GET_SHA1_COMMIT,
+ sha1, &unused);
+}
+
+int get_sha1_tree(const char *name, unsigned char *sha1)
+{
+ struct object_context unused;
+ return get_sha1_with_context(name, GET_SHA1_TREE,
+ sha1, &unused);
+}
+
+int get_sha1_blob(const char *name, unsigned char *sha1)
+{
+ struct object_context unused;
+ return get_sha1_with_context(name, GET_SHA1_BLOB,
+ sha1, &unused);
}
/* Must be called only when object_name:filename doesn't exist. */
@@ -1004,16 +1229,6 @@ static void diagnose_invalid_index_path(int stage,
}
-int get_sha1_with_mode_1(const char *name, unsigned char *sha1, unsigned *mode,
- int only_to_die, const char *prefix)
-{
- struct object_context oc;
- int ret;
- ret = get_sha1_with_context_1(name, sha1, &oc, only_to_die, prefix);
- *mode = oc.mode;
- return ret;
-}
-
static char *resolve_relative_path(const char *rel)
{
if (prefixcmp(rel, "./") && prefixcmp(rel, "../"))
@@ -1031,20 +1246,24 @@ static char *resolve_relative_path(const char *rel)
rel);
}
-int get_sha1_with_context_1(const char *name, unsigned char *sha1,
- struct object_context *oc,
- int only_to_die, const char *prefix)
+static int get_sha1_with_context_1(const char *name,
+ unsigned flags,
+ const char *prefix,
+ unsigned char *sha1,
+ struct object_context *oc)
{
int ret, bracket_depth;
int namelen = strlen(name);
const char *cp;
+ int only_to_die = flags & GET_SHA1_ONLY_TO_DIE;
memset(oc, 0, sizeof(*oc));
oc->mode = S_IFINVALID;
- ret = get_sha1_1(name, namelen, sha1);
+ ret = get_sha1_1(name, namelen, sha1, flags);
if (!ret)
return ret;
- /* sha1:path --> object name of path in ent sha1
+ /*
+ * sha1:path --> object name of path in ent sha1
* :path -> object name of absolute path in index
* :./path -> object name of path relative to cwd in index
* :[0-3]:path -> object name of path in index at stage
@@ -1119,7 +1338,7 @@ int get_sha1_with_context_1(const char *name, unsigned char *sha1,
strncpy(object_name, name, cp-name);
object_name[cp-name] = '\0';
}
- if (!get_sha1_1(name, cp-name, tree_sha1)) {
+ if (!get_sha1_1(name, cp-name, tree_sha1, GET_SHA1_TREEISH)) {
const char *filename = cp+1;
char *new_filename = NULL;
@@ -1146,3 +1365,22 @@ int get_sha1_with_context_1(const char *name, unsigned char *sha1,
}
return ret;
}
+
+/*
+ * Call this function when you know "name" given by the end user must
+ * name an object but it doesn't; the function _may_ die with a better
+ * diagnostic message than "no such object 'name'", e.g. "Path 'doc' does not
+ * exist in 'HEAD'" when given "HEAD:doc", or it may return in which case
+ * you have a chance to diagnose the error further.
+ */
+void maybe_die_on_misspelt_object_name(const char *name, const char *prefix)
+{
+ struct object_context oc;
+ unsigned char sha1[20];
+ get_sha1_with_context_1(name, GET_SHA1_ONLY_TO_DIE, prefix, sha1, &oc);
+}
+
+int get_sha1_with_context(const char *str, unsigned flags, unsigned char *sha1, struct object_context *orc)
+{
+ return get_sha1_with_context_1(str, flags, NULL, sha1, orc);
+}