read-tree: reorganize bind_merge code.
[git.git] / read-tree.c
index 1c3b09b..fb1d682 100644 (file)
@@ -9,6 +9,7 @@
 
 #include "object.h"
 #include "tree.h"
+#include "cache-tree.h"
 #include <sys/time.h>
 #include <signal.h>
 
@@ -20,6 +21,7 @@ static int trivial_merges_only = 0;
 static int aggressive = 0;
 static int verbose_update = 0;
 static volatile int progress_update = 0;
+static const char *prefix = NULL;
 
 static int head_idx = -1;
 static int merge_size = 0;
@@ -133,11 +135,9 @@ static int unpack_trees_rec(struct tree_entry_list **posns, int len,
                pathlen = strlen(first);
                ce_size = cache_entry_size(baselen + pathlen);
 
-               src = xmalloc(sizeof(struct cache_entry *) * src_size);
-               memset(src, 0, sizeof(struct cache_entry *) * src_size);
+               src = xcalloc(src_size, sizeof(struct cache_entry *));
 
-               subposns = xmalloc(sizeof(struct tree_list_entry *) * len);
-               memset(subposns, 0, sizeof(struct tree_list_entry *) * len);
+               subposns = xcalloc(len, sizeof(struct tree_list_entry *));
 
                if (cache_name && !strcmp(cache_name, first)) {
                        any_files = 1;
@@ -177,8 +177,7 @@ static int unpack_trees_rec(struct tree_entry_list **posns, int len,
                        else
                                ce_stage = 2;
 
-                       ce = xmalloc(ce_size);
-                       memset(ce, 0, ce_size);
+                       ce = xcalloc(1, ce_size);
                        ce->ce_mode = create_ce_mode(posns[i]->mode);
                        ce->ce_flags = create_ce_flags(baselen + pathlen,
                                                       ce_stage);
@@ -273,10 +272,26 @@ static void unlink_entry(char *name)
 
 static void progress_interval(int signum)
 {
-       signal(SIGALRM, progress_interval);
        progress_update = 1;
 }
 
+static void setup_progress_signal(void)
+{
+       struct sigaction sa;
+       struct itimerval v;
+
+       memset(&sa, 0, sizeof(sa));
+       sa.sa_handler = progress_interval;
+       sigemptyset(&sa.sa_mask);
+       sa.sa_flags = SA_RESTART;
+       sigaction(SIGALRM, &sa, NULL);
+
+       v.it_interval.tv_sec = 1;
+       v.it_interval.tv_usec = 0;
+       v.it_value = v.it_interval;
+       setitimer(ITIMER_REAL, &v, NULL);
+}
+
 static void check_updates(struct cache_entry **src, int nr)
 {
        static struct checkout state = {
@@ -289,8 +304,6 @@ static void check_updates(struct cache_entry **src, int nr)
        unsigned last_percent = 200, cnt = 0, total = 0;
 
        if (update && verbose_update) {
-               struct itimerval v;
-
                for (total = cnt = 0; cnt < nr; cnt++) {
                        struct cache_entry *ce = src[cnt];
                        if (!ce->ce_mode || ce->ce_flags & mask)
@@ -302,12 +315,8 @@ static void check_updates(struct cache_entry **src, int nr)
                        total = 0;
 
                if (total) {
-                       v.it_interval.tv_sec = 1;
-                       v.it_interval.tv_usec = 0;
-                       v.it_value = v.it_interval;
-                       signal(SIGALRM, progress_interval);
-                       setitimer(ITIMER_REAL, &v, NULL);
                        fprintf(stderr, "Checking files out...\n");
+                       setup_progress_signal();
                        progress_update = 1;
                }
                cnt = 0;
@@ -341,8 +350,8 @@ static void check_updates(struct cache_entry **src, int nr)
                }
        }
        if (total) {
-               fputc('\n', stderr);
                signal(SIGALRM, SIG_IGN);
+               fputc('\n', stderr);
        }
 }
 
@@ -361,7 +370,8 @@ static int unpack_trees(merge_fn_t fn)
                        posns[i] = ((struct tree *) posn->item)->entries;
                        posn = posn->next;
                }
-               if (unpack_trees_rec(posns, len, "", fn, &indpos))
+               if (unpack_trees_rec(posns, len, prefix ? prefix : "",
+                                    fn, &indpos))
                        return -1;
        }
 
@@ -414,6 +424,12 @@ static void verify_uptodate(struct cache_entry *ce)
        die("Entry '%s' not uptodate. Cannot merge.", ce->name);
 }
 
+static void invalidate_ce_path(struct cache_entry *ce)
+{
+       if (ce)
+               cache_tree_invalidate_path(active_cache_tree, ce->name);
+}
+
 static int merged_entry(struct cache_entry *merge, struct cache_entry *old)
 {
        merge->ce_flags |= htons(CE_UPDATE);
@@ -429,6 +445,7 @@ static int merged_entry(struct cache_entry *merge, struct cache_entry *old)
                        *merge = *old;
                } else {
                        verify_uptodate(old);
+                       invalidate_ce_path(old);
                }
        }
        merge->ce_flags &= ~htons(CE_STAGEMASK);
@@ -442,6 +459,7 @@ static int deleted_entry(struct cache_entry *ce, struct cache_entry *old)
                verify_uptodate(old);
        ce->ce_mode = 0;
        add_cache_entry(ce, ADD_CACHE_OK_TO_ADD);
+       invalidate_ce_path(ce);
        return 1;
 }
 
@@ -662,6 +680,28 @@ static int twoway_merge(struct cache_entry **src)
 }
 
 /*
+ * Bind merge.
+ *
+ * Keep the index entries at stage0, collapse stage1 but make sure
+ * stage0 does not have anything there.
+ */
+static int bind_merge(struct cache_entry **src)
+{
+       struct cache_entry *old = src[0];
+       struct cache_entry *a = src[1];
+
+       if (merge_size != 1)
+               return error("Cannot do a bind merge of %d trees\n",
+                            merge_size);
+       if (a && old)
+               die("Entry '%s' overlaps.  Cannot bind.", a->name);
+       if (!a)
+               return keep_entry(old);
+       else
+               return merged_entry(a, NULL);
+}
+
+/*
  * One-way merge.
  *
  * The rule is:
@@ -676,8 +716,10 @@ static int oneway_merge(struct cache_entry **src)
                return error("Cannot do a oneway merge of %d trees",
                             merge_size);
 
-       if (!a)
+       if (!a) {
+               invalidate_ce_path(old);
                return 0;
+       }
        if (old && same(old, a)) {
                return keep_entry(old);
        }
@@ -696,6 +738,7 @@ static int read_cache_unmerged(void)
                struct cache_entry *ce = active_cache[i];
                if (ce_stage(ce)) {
                        deleted++;
+                       invalidate_ce_path(ce);
                        continue;
                }
                if (deleted)
@@ -706,7 +749,40 @@ static int read_cache_unmerged(void)
        return deleted;
 }
 
-static const char read_tree_usage[] = "git-read-tree (<sha> | -m [--aggressive] [-u | -i] <sha1> [<sha2> [<sha3>]])";
+static void prime_cache_tree_rec(struct cache_tree *it, struct tree *tree)
+{
+       struct tree_entry_list *ent;
+       int cnt;
+       
+       memcpy(it->sha1, tree->object.sha1, 20);
+       for (cnt = 0, ent = tree->entries; ent; ent = ent->next) {
+               if (!ent->directory)
+                       cnt++;
+               else {
+                       struct cache_tree_sub *sub;
+                       struct tree *subtree = (struct tree *)ent->item.tree;
+                       if (!subtree->object.parsed)
+                               parse_tree(subtree);
+                       sub = cache_tree_sub(it, ent->name);
+                       sub->cache_tree = cache_tree();
+                       prime_cache_tree_rec(sub->cache_tree, subtree);
+                       cnt += sub->cache_tree->entry_count;
+               }
+       }
+       it->entry_count = cnt;
+}
+
+static void prime_cache_tree(void)
+{
+       struct tree *tree = (struct tree *)trees->item;
+       if (!tree)
+               return;
+       active_cache_tree = cache_tree();
+       prime_cache_tree_rec(active_cache_tree, tree);
+
+}
+
+static const char read_tree_usage[] = "git-read-tree (<sha> | [[-m [--aggressive] | --reset | --prefix=<prefix>] [-u | -i]] <sha1> [<sha2> [<sha3>]])";
 
 static struct cache_file cache_file;
 
@@ -717,6 +793,7 @@ int main(int argc, char **argv)
        merge_fn_t fn = NULL;
 
        setup_git_directory();
+       git_config(git_default_config);
 
        newfd = hold_index_file_for_update(&cache_file, get_index_file());
        if (newfd < 0)
@@ -750,9 +827,24 @@ int main(int argc, char **argv)
                        continue;
                }
 
+               /* "--prefix=<subdirectory>/" means keep the current index
+                *  entries and put the entries from the tree under the
+                * given subdirectory.
+                */
+               if (!strncmp(arg, "--prefix=", 9)) {
+                       if (stage || merge || prefix)
+                               usage(read_tree_usage);
+                       prefix = arg + 9;
+                       merge = 1;
+                       stage = 1;
+                       if (read_cache_unmerged())
+                               die("you need to resolve your current index first");
+                       continue;
+               }
+
                /* This differs from "-m" in that we'll silently ignore unmerged entries */
                if (!strcmp(arg, "--reset")) {
-                       if (stage || merge)
+                       if (stage || merge || prefix)
                                usage(read_tree_usage);
                        reset = 1;
                        merge = 1;
@@ -773,7 +865,7 @@ int main(int argc, char **argv)
 
                /* "-m" stands for "merge", meaning we start in stage 1 */
                if (!strcmp(arg, "-m")) {
-                       if (stage || merge)
+                       if (stage || merge || prefix)
                                usage(read_tree_usage);
                        if (read_cache_unmerged())
                                die("you need to resolve your current index first");
@@ -795,21 +887,39 @@ int main(int argc, char **argv)
        if ((update||index_only) && !merge)
                usage(read_tree_usage);
 
+       if (prefix) {
+               int pfxlen = strlen(prefix);
+               int pos;
+               if (prefix[pfxlen-1] != '/')
+                       die("prefix must end with /");
+               if (stage != 2)
+                       die("binding merge takes only one tree");
+               pos = cache_name_pos(prefix, pfxlen);
+               if (0 <= pos)
+                       die("corrupt index file");
+               pos = -pos-1;
+               if (pos < active_nr &&
+                   !strncmp(active_cache[pos]->name, prefix, pfxlen))
+                       die("subdirectory '%s' already exists.", prefix);
+               pos = cache_name_pos(prefix, pfxlen-1);
+               if (0 <= pos)
+                       die("file '%.*s' already exists.", pfxlen-1, prefix);
+       }
+
        if (merge) {
                if (stage < 2)
                        die("just how do you expect me to merge %d trees?", stage-1);
                switch (stage - 1) {
                case 1:
-                       fn = oneway_merge;
+                       fn = prefix ? bind_merge : oneway_merge;
                        break;
                case 2:
                        fn = twoway_merge;
                        break;
                case 3:
-                       fn = threeway_merge;
-                       break;
                default:
                        fn = threeway_merge;
+                       cache_tree_free(&active_cache_tree);
                        break;
                }
 
@@ -820,6 +930,18 @@ int main(int argc, char **argv)
        }
 
        unpack_trees(fn);
+
+       /*
+        * When reading only one tree (either the most basic form,
+        * "-m ent" or "--reset ent" form), we can obtain a fully
+        * valid cache-tree because the index must match exactly
+        * what came from the tree.
+        */
+       if (trees->item && !prefix && (!merge || (stage == 2))) {
+               cache_tree_free(&active_cache_tree);
+               prime_cache_tree();
+       }
+
        if (write_cache(newfd, active_cache, active_nr) ||
            commit_index_file(&cache_file))
                die("unable to write new index file");