Show changes to read-tree.c +297 −225
diff --git a/read-tree.c b/read-tree.c
--- a/read-tree.c
+++ b/read-tree.c
@@ -5,28 +5,280 @@
*/
#include "cache.h"
-static int stage = 0;
+#include "object.h"
+#include "tree.h"
+
+static int merge = 0;
+static int emu23 = 0;
static int update = 0;
-static int unpack_tree(unsigned char *sha1)
+static struct object_list *trees = NULL;
+
+typedef int (*merge_fn_t)(struct cache_entry **src,
+ struct cache_entry **dest,
+ int df_conflicts_2,
+ int df_conflicts_3);
+
+static int unpack_trees_rec(struct tree_entry_list **posns, int len,
+ const char *base, merge_fn_t fn,
+ int file2, int file3, int *indpos)
+{
+ int baselen = strlen(base);
+ int src_size = len + 1;
+ if (emu23)
+ src_size++;
+ if (src_size > 4)
+ src_size = 4;
+ do {
+ int i;
+ char *first = NULL;
+ int pathlen;
+ unsigned ce_size;
+ int dir2 = 0;
+ int dir3 = 0;
+ int subfile2 = file2;
+ int subfile3 = file3;
+ struct tree_entry_list **subposns = NULL;
+ struct cache_entry **src = NULL;
+ char *cache_name = NULL;
+
+ /* Find the first name in the input. */
+
+ /* Check the cache */
+ if (merge && *indpos < active_nr) {
+ /* This is a bit tricky: */
+ /* If the index has a subdirectory (with
+ * contents) as the first name, it'll get a
+ * filename like "foo/bar". But that's after
+ * "foo", so the entry in trees will get
+ * handled first, at which point we'll go into
+ * "foo", and deal with "bar" from the index,
+ * because the base will be "foo/". The only
+ * way we can actually have "foo/bar" first of
+ * all the things is if the trees don't
+ * contain "foo" at all, in which case we'll
+ * handle "foo/bar" without going into the
+ * directory, but that's fine (and will return
+ * an error anyway, with the added unknown
+ * file case.
+ */
+
+ cache_name = active_cache[*indpos]->name;
+ if (strlen(cache_name) > baselen &&
+ !memcmp(cache_name, base, baselen)) {
+ cache_name += baselen;
+ first = cache_name;
+ } else {
+ cache_name = NULL;
+ }
+ }
+
+ for (i = 0; i < len; i++) {
+ if (!posns[i])
+ continue;
+ if (!first || strcmp(first, posns[i]->name) > 0)
+ first = posns[i]->name;
+ }
+ /* No name means we're done */
+ if (!first)
+ return 0;
+
+ pathlen = strlen(first);
+ ce_size = cache_entry_size(baselen + pathlen);
+
+ if (cache_name && !strcmp(cache_name, first)) {
+ src = xmalloc(sizeof(struct cache_entry *) *
+ src_size);
+ memset(src, 0,
+ sizeof(struct cache_entry *) *
+ src_size);
+ src[0] = active_cache[*indpos];
+ remove_cache_entry_at(*indpos);
+ if (emu23) {
+ // we need this in stage 2 as well as stage 0
+ struct cache_entry *copy =
+ xmalloc(ce_size);
+ memcpy(copy, src[0], ce_size);
+ copy->ce_flags =
+ create_ce_flags(baselen + pathlen, 2);
+ if (dir2 || file2) {
+ die("cannot merge index and our head tree");
+ }
+ src[2] = copy;
+ subfile2 = 1;
+ }
+ }
+
+ for (i = 0; i < len; i++) {
+ struct cache_entry *ce;
+ int ce_stage;
+ if (!posns[i] ||
+ strcmp(first, posns[i]->name)) {
+ continue;
+ }
+
+ if (len > 3) {
+ if (i - len + 3 >= 0)
+ ce_stage = i - len + 3 + merge;
+ else
+ ce_stage = merge;
+ } else {
+ ce_stage = i + merge;
+ }
+ if (emu23 && ce_stage == 2)
+ ce_stage = 3;
+
+ if (posns[i]->directory) {
+ if (!subposns) {
+ int posnlen = sizeof(struct tree_list_entry *) * len;
+ subposns = xmalloc(posnlen);
+ memset(subposns, 0, posnlen);
+ }
+ parse_tree(posns[i]->item.tree);
+ subposns[i] = posns[i]->item.tree->entries;
+ posns[i] = posns[i]->next;
+ if (emu23 && ce_stage == 1)
+ dir2 = 1;
+ if (ce_stage == 2)
+ dir2 = 1;
+ if (ce_stage == 3)
+ dir3 = 1;
+ continue;
+ }
+
+ if (ce_stage == 2)
+ subfile2 = 1;
+ if (ce_stage == 3)
+ subfile3 = 1;
+
+ ce = xmalloc(ce_size);
+ memset(ce, 0, ce_size);
+ ce->ce_mode = create_ce_mode(posns[i]->mode);
+ ce->ce_flags = create_ce_flags(baselen + pathlen,
+ ce_stage);
+ memcpy(ce->name, base, baselen);
+ memcpy(ce->name + baselen, first, pathlen + 1);
+
+ if (!src) {
+ src = xmalloc(sizeof(struct cache_entry *) *
+ src_size);
+ memset(src, 0,
+ sizeof(struct cache_entry *) *
+ src_size);
+ }
+
+ memcpy(ce->sha1, posns[i]->item.any->sha1, 20);
+ if (ce_stage == 1 && emu23 && !src[2]) {
+ // we need this in stage 2 as well as stage 1
+ struct cache_entry *copy =
+ xmalloc(ce_size);
+ memcpy(copy, ce, ce_size);
+ copy->ce_flags =
+ create_ce_flags(baselen + pathlen, 2);
+ if (dir2 || file2) {
+ die("cannot merge index and our head tree");
+ }
+ src[2] = copy;
+ subfile2 = 1;
+ }
+ src[ce_stage] = ce;
+ posns[i] = posns[i]->next;
+ }
+ if (src) {
+ if (fn) {
+ int ret;
+ /*
+ printf("%s:\n", first);
+ for (i = 0; i < src_size; i++) {
+ printf(" %d ", i);
+ if (src[i])
+ printf("%s\n", sha1_to_hex(src[i]->sha1));
+ else
+ printf("\n");
+ }
+ */
+ ret = fn(src, NULL,
+ (file2 || dir2),
+ (file3 || dir3));
+ /*printf("Added %d entries\n", ret);*/
+ *indpos += ret;
+ } else {
+ for (i = 0; i < src_size; i++) {
+ if (src[i]) {
+ add_cache_entry(src[i], ADD_CACHE_OK_TO_ADD|ADD_CACHE_SKIP_DFCHECK);
+ }
+ }
+ }
+ }
+ if (subposns) {
+ char *newbase = xmalloc(baselen + 2 + pathlen);
+ memcpy(newbase, base, baselen);
+ memcpy(newbase + baselen, first, pathlen);
+ newbase[baselen + pathlen] = '/';
+ newbase[baselen + pathlen + 1] = '\0';
+ if (unpack_trees_rec(subposns, len, newbase, fn,
+ subfile2, subfile3, indpos))
+ return -1;
+ }
+ } while (1);
+}
+
+static void reject_merge(struct cache_entry *ce)
+{
+ die("Entry '%s' would be overwritten by merge. Cannot merge.",
+ ce->name);
+}
+
+static void check_updates(struct cache_entry **src, int nr)
{
- void *buffer;
- unsigned long size;
- int ret;
+ static struct checkout state = {
+ .base_dir = "",
+ .force = 1,
+ .quiet = 1,
+ .refresh_cache = 1,
+ };
+ unsigned short mask = htons(CE_UPDATE);
+ while (nr--) {
+ struct cache_entry *ce = *src++;
+ if (!ce->ce_mode) {
+ if (update)
+ unlink(ce->name);
+ continue;
+ }
+ if (ce->ce_flags & mask) {
+ ce->ce_flags &= ~mask;
+ if (update)
+ checkout_entry(ce, &state);
+ }
+ }
+}
- buffer = read_object_with_reference(sha1, "tree", &size, NULL);
- if (!buffer)
+static int unpack_trees(merge_fn_t fn)
+{
+ int indpos = 0;
+ unsigned len = object_list_length(trees);
+ struct tree_entry_list **posns =
+ xmalloc(len * sizeof(struct tree_entry_list *));
+ int i;
+ struct object_list *posn = trees;
+ for (i = 0; i < len; i++) {
+ posns[i] = ((struct tree *) posn->item)->entries;
+ posn = posn->next;
+ }
+ if (unpack_trees_rec(posns, len, "", fn, 0, 0, &indpos))
return -1;
- ret = read_tree(buffer, size, stage, NULL);
- free(buffer);
- return ret;
+
+ check_updates(active_cache, active_nr);
+ return 0;
}
-static int path_matches(struct cache_entry *a, struct cache_entry *b)
+static int list_tree(unsigned char *sha1)
{
- int len = ce_namelen(a);
- return ce_namelen(b) == len &&
- !memcmp(a->name, b->name, len);
+ struct tree *tree = parse_tree_indirect(sha1);
+ if (!tree)
+ return -1;
+ object_list_append(&tree->object, &trees);
+ return 0;
}
static int same(struct cache_entry *a, struct cache_entry *b)
@@ -91,17 +343,6 @@ static void verify_uptodate(struct cache
die("Entry '%s' not uptodate. Cannot merge.", ce->name);
}
-/*
- * If the old tree contained a CE that isn't even in the
- * result, that's always a problem, regardless of whether
- * it's up-to-date or not (ie it can be a file that we
- * have updated but not committed yet).
- */
-static void reject_merge(struct cache_entry *ce)
-{
- die("Entry '%s' would be overwritten by merge. Cannot merge.", ce->name);
-}
-
static int merged_entry_internal(struct cache_entry *merge, struct cache_entry *old, struct cache_entry **dst, int allow_dirty)
{
merge->ce_flags |= htons(CE_UPDATE);
@@ -120,7 +361,7 @@ static int merged_entry_internal(struct
}
}
merge->ce_flags &= ~htons(CE_STAGEMASK);
- *dst++ = merge;
+ add_cache_entry(merge, ADD_CACHE_OK_TO_ADD);
return 1;
}
@@ -139,76 +380,19 @@ static int deleted_entry(struct cache_en
if (old)
verify_uptodate(old);
ce->ce_mode = 0;
- *dst++ = ce;
+ add_cache_entry(ce, ADD_CACHE_OK_TO_ADD);
return 1;
}
-static int causes_df_conflict(struct cache_entry *ce, int stage,
- struct cache_entry **dst_,
- struct cache_entry **next_,
- int tail)
-{
- /* This is called during the merge operation and walking
- * the active_cache[] array is messy, because it is in the
- * middle of overlapping copy operation. The invariants
- * are:
- * (1) active_cache points at the first (zeroth) entry.
- * (2) up to dst pointer are resolved entries.
- * (3) from the next pointer (head-inclusive) to the tail
- * of the active_cache array have the remaining paths
- * to be processed. There can be a gap between dst
- * and next. Note that next is called "src" in the
- * merge_cache() function, and tail is the original
- * end of active_cache array when merge_cache() started.
- * (4) the path corresponding to *ce is not found in (2)
- * or (3). It is in the gap.
- *
- * active_cache -----......+++++++++++++.
- * ^dst ^next ^tail
- */
- int i, next, dst;
- const char *path = ce->name;
- int namelen = ce_namelen(ce);
-
- next = next_ - active_cache;
- dst = dst_ - active_cache;
-
- for (i = 0; i < tail; i++) {
- int entlen, len;
- const char *one, *two;
- if (dst <= i && i < next)
- continue;
- ce = active_cache[i];
- if (ce_stage(ce) != stage)
- continue;
- /* If ce->name is a prefix of path, then path is a file
- * that hangs underneath ce->name, which is bad.
- * If path is a prefix of ce->name, then it is the
- * other way around which also is bad.
- */
- entlen = ce_namelen(ce);
- if (namelen == entlen)
- continue;
- if (namelen < entlen) {
- len = namelen;
- one = path;
- two = ce->name;
- } else {
- len = entlen;
- one = ce->name;
- two = path;
- }
- if (memcmp(one, two, len))
- continue;
- if (two[len] == '/')
- return 1;
- }
- return 0;
+static int keep_entry(struct cache_entry *ce, struct cache_entry **dst)
+{
+ add_cache_entry(ce, ADD_CACHE_OK_TO_ADD);
+ return 1;
}
static int threeway_merge(struct cache_entry *stages[4],
struct cache_entry **dst,
- struct cache_entry **next, int tail)
+ int df_conflict_2, int df_conflict_3)
{
struct cache_entry *old = stages[0];
struct cache_entry *a = stages[1], *b = stages[2], *c = stages[3];
@@ -218,7 +402,7 @@ static int threeway_merge(struct cache_e
/* #5ALT */
if (!a && b && c && same(b, c)) {
if (old && !same(b, old))
- return -1;
+ reject_merge(old);
return merged_entry_allow_dirty(b, old, dst);
}
/* #2ALT and #3ALT */
@@ -269,12 +453,12 @@ static int threeway_merge(struct cache_e
* and vice versa.
*/
if (c) { /* #2ALT */
- if (!causes_df_conflict(c, 2, dst, next, tail) &&
+ if (!df_conflict_2 &&
(!old || same(c, old)))
return merged_entry_allow_dirty(c, old, dst);
}
else { /* #3ALT */
- if (!causes_df_conflict(b, 3, dst, next, tail) &&
+ if (!df_conflict_3 &&
(!old || same(b, old)))
return merged_entry_allow_dirty(b, old, dst);
}
@@ -293,7 +477,7 @@ static int threeway_merge(struct cache_e
*/
if (old) {
if (!b || !same(old, b))
- return -1;
+ reject_merge(old);
}
merge = merge_entries(a, b, c);
if (merge)
@@ -301,9 +485,9 @@ static int threeway_merge(struct cache_e
if (old)
verify_uptodate(old);
count = 0;
- if (a) { *dst++ = a; count++; }
- if (b) { *dst++ = b; count++; }
- if (c) { *dst++ = c; count++; }
+ if (a) { count += keep_entry(a, dst + count); }
+ if (b) { count += keep_entry(b, dst + count); }
+ if (c) { count += keep_entry(c, dst + count); }
return count;
}
@@ -317,14 +501,11 @@ static int threeway_merge(struct cache_e
*
*/
static int twoway_merge(struct cache_entry **src, struct cache_entry **dst,
- struct cache_entry **next, int tail)
+ int df23, int df32)
{
struct cache_entry *current = src[0];
struct cache_entry *oldtree = src[1], *newtree = src[2];
- if (src[3])
- return -1;
-
if (current) {
if ((!oldtree && !newtree) || /* 4 and 5 */
(!oldtree && newtree &&
@@ -334,8 +515,7 @@ static int twoway_merge(struct cache_ent
(oldtree && newtree &&
!same(oldtree, newtree) && /* 18 and 19*/
same(current, newtree))) {
- *dst++ = current;
- return 1;
+ return keep_entry(current, dst);
}
else if (oldtree && !newtree && same(current, oldtree)) {
/* 10 or 11 */
@@ -346,9 +526,16 @@ static int twoway_merge(struct cache_ent
/* 20 or 21 */
return merged_entry(newtree, current, dst);
}
- else
+ else {
/* all other failures */
+ if (oldtree)
+ reject_merge(oldtree);
+ if (current)
+ reject_merge(current);
+ if (newtree)
+ reject_merge(newtree);
return -1;
+ }
}
else if (newtree)
return merged_entry(newtree, current, dst);
@@ -357,137 +544,25 @@ static int twoway_merge(struct cache_ent
}
/*
- * Two-way merge emulated with three-way merge.
- *
- * This treats "read-tree -m H M" by transforming it internally
- * into "read-tree -m H I+H M", where I+H is a tree that would
- * contain the contents of the current index file, overlayed on
- * top of H. Unlike the traditional two-way merge, this leaves
- * the stages in the resulting index file and lets the user resolve
- * the merge conflicts using standard tools for three-way merge.
- *
- * This function is just to set-up such an arrangement, and the
- * actual merge uses threeway_merge() function.
- */
-static void setup_emu23(void)
-{
- /* stage0 contains I, stage1 H, stage2 M.
- * move stage2 to stage3, and create stage2 entries
- * by scanning stage0 and stage1 entries.
- */
- int i, namelen, size;
- struct cache_entry *ce, *stage2;
-
- for (i = 0; i < active_nr; i++) {
- ce = active_cache[i];
- if (ce_stage(ce) != 2)
- continue;
- /* hoist them up to stage 3 */
- namelen = ce_namelen(ce);
- ce->ce_flags = create_ce_flags(namelen, 3);
- }
-
- for (i = 0; i < active_nr; i++) {
- ce = active_cache[i];
- if (ce_stage(ce) > 1)
- continue;
- namelen = ce_namelen(ce);
- size = cache_entry_size(namelen);
- stage2 = xmalloc(size);
- memcpy(stage2, ce, size);
- stage2->ce_flags = create_ce_flags(namelen, 2);
- if (add_cache_entry(stage2, ADD_CACHE_OK_TO_ADD) < 0)
- die("cannot merge index and our head tree");
-
- /* We are done with this name, so skip to next name */
- while (i < active_nr &&
- ce_namelen(active_cache[i]) == namelen &&
- !memcmp(active_cache[i]->name, ce->name, namelen))
- i++;
- i--; /* compensate for the loop control */
- }
-}
-
-/*
* One-way merge.
*
* The rule is:
* - take the stat information from stage0, take the data from stage1
*/
static int oneway_merge(struct cache_entry **src, struct cache_entry **dst,
- struct cache_entry **next, int tail)
+ int df23, int df32)
{
struct cache_entry *old = src[0];
struct cache_entry *a = src[1];
- if (src[2] || src[3])
- return -1;
-
if (!a)
return 0;
if (old && same(old, a)) {
- *dst++ = old;
- return 1;
+ return keep_entry(old, dst);
}
return merged_entry(a, NULL, dst);
}
-static void check_updates(struct cache_entry **src, int nr)
-{
- static struct checkout state = {
- .base_dir = "",
- .force = 1,
- .quiet = 1,
- .refresh_cache = 1,
- };
- unsigned short mask = htons(CE_UPDATE);
- while (nr--) {
- struct cache_entry *ce = *src++;
- if (!ce->ce_mode) {
- if (update)
- unlink(ce->name);
- continue;
- }
- if (ce->ce_flags & mask) {
- ce->ce_flags &= ~mask;
- if (update)
- checkout_entry(ce, &state);
- }
- }
-}
-
-typedef int (*merge_fn_t)(struct cache_entry **, struct cache_entry **, struct cache_entry **, int);
-
-static void merge_cache(struct cache_entry **src, int nr, merge_fn_t fn)
-{
- struct cache_entry **dst = src;
- int tail = nr;
-
- while (nr) {
- int entries;
- struct cache_entry *name, *ce, *stages[4] = { NULL, };
-
- name = ce = *src;
- for (;;) {
- int stage = ce_stage(ce);
- stages[stage] = ce;
- ce = *++src;
- active_nr--;
- if (!--nr)
- break;
- if (!path_matches(ce, name))
- break;
- }
-
- entries = fn(stages, dst, src, tail);
- if (entries < 0)
- reject_merge(name);
- dst += entries;
- active_nr += entries;
- }
- check_updates(active_cache, active_nr);
-}
-
static int read_cache_unmerged(void)
{
int i, deleted;
@@ -516,8 +591,9 @@ static struct cache_file cache_file;
int main(int argc, char **argv)
{
- int i, newfd, merge, reset, emu23;
+ int i, newfd, reset, stage = 0;
unsigned char sha1[20];
+ merge_fn_t fn = NULL;
newfd = hold_index_file_for_update(&cache_file, get_index_file());
if (newfd < 0)
@@ -569,9 +645,7 @@ int main(int argc, char **argv)
if (get_sha1(arg, sha1) < 0)
usage(read_tree_usage);
- if (stage > 3)
- usage(read_tree_usage);
- if (unpack_tree(sha1) < 0)
+ if (list_tree(sha1) < 0)
die("failed to unpack tree object %s", arg);
stage++;
}
@@ -583,19 +657,17 @@ int main(int argc, char **argv)
[2] = twoway_merge,
[3] = threeway_merge,
};
- merge_fn_t fn;
- if (stage < 2 || stage > 4)
+ if (stage < 2)
die("just how do you expect me to merge %d trees?", stage-1);
if (emu23 && stage != 3)
die("--emu23 takes only two trees");
fn = merge_function[stage-1];
if (stage == 3 && emu23) {
- setup_emu23();
fn = merge_function[3];
}
- merge_cache(active_cache, active_nr, fn);
}
+ unpack_trees(fn);
if (write_cache(newfd, active_cache, active_nr) ||
commit_index_file(&cache_file))
die("unable to write new index file");
Daniel Barkalow