update-index: be specific what part of the index has changed

diff --git a/read-cache.c b/read-cache.c
index ba13353b377d4f27b9ff6cf1b85811fcca61e224..035c72e101fcb0935ba4e5fca5aa69a21d4cba51 100644 (file)
--- a/read-cache.c
+++ b/read-cache.c
@@ -36,6 +36,7 @@ static struct cache_entry *refresh_cache_entry(struct cache_entry *ce,
 #define CACHE_EXT_RESOLVE_UNDO 0x52455543 /* "REUC" */
 
 struct index_state the_index;
+static const char *alternate_index_output;
 
 static void set_index_entry(struct index_state *istate, int nr, struct cache_entry *ce)
 {
@@ -50,7 +51,7 @@ static void replace_index_entry(struct index_state *istate, int nr, struct cache
        remove_name_hash(istate, old);
        free(old);
        set_index_entry(istate, nr, ce);
-       istate->cache_changed = 1;
+       istate->cache_changed |= CE_ENTRY_CHANGED;
 }
 
 void rename_index_entry_at(struct index_state *istate, int nr, const char *new_name)
@@ -481,7 +482,7 @@ int remove_index_entry_at(struct index_state *istate, int pos)
        record_resolve_undo(istate, ce);
        remove_name_hash(istate, ce);
        free(ce);
-       istate->cache_changed = 1;
+       istate->cache_changed |= CE_ENTRY_REMOVED;
        istate->cache_nr--;
        if (pos >= istate->cache_nr)
                return 0;
@@ -509,7 +510,9 @@ void remove_marked_cache_entries(struct index_state *istate)
                else
                        ce_array[j++] = ce_array[i];
        }
-       istate->cache_changed = 1;
+       if (j == istate->cache_nr)
+               return;
+       istate->cache_changed |= CE_ENTRY_REMOVED;
        istate->cache_nr = j;
 }
 
@@ -999,7 +1002,7 @@ int add_index_entry(struct index_state *istate, struct cache_entry *ce, int opti
                        istate->cache + pos,
                        (istate->cache_nr - pos - 1) * sizeof(ce));
        set_index_entry(istate, pos, ce);
-       istate->cache_changed = 1;
+       istate->cache_changed |= CE_ENTRY_ADDED;
        return 0;
 }
 
@@ -1098,6 +1101,7 @@ static struct cache_entry *refresh_cache_ent(struct index_state *istate,
            !(ce->ce_flags & CE_VALID))
                updated->ce_flags &= ~CE_VALID;
 
+       /* istate->cache_changed is updated in the caller */
        return updated;
 }
 
@@ -1179,7 +1183,7 @@ int refresh_index(struct index_state *istate, unsigned int flags,
                                 * means the index is not valid anymore.
                                 */
                                ce->ce_flags &= ~CE_VALID;
-                               istate->cache_changed = 1;
+                               istate->cache_changed |= CE_ENTRY_CHANGED;
                        }
                        if (quiet)
                                continue;
@@ -1701,7 +1705,7 @@ static char *copy_cache_entry_to_ondisk(struct ondisk_cache_entry *ondisk,
        ondisk->size = htonl(ce->ce_stat_data.sd_size);
        hashcpy(ondisk->sha1, ce->sha1);
 
-       flags = ce->ce_flags;
+       flags = ce->ce_flags & ~CE_NAMEMASK;
        flags |= (ce_namelen(ce) >= CE_NAMEMASK ? CE_NAMEMASK : ce_namelen(ce));
        ondisk->flags = htons(flags);
        if (ce->ce_flags & CE_EXTENDED) {
@@ -1779,13 +1783,11 @@ static int has_racy_timestamp(struct index_state *istate)
 void update_index_if_able(struct index_state *istate, struct lock_file *lockfile)
 {
        if ((istate->cache_changed || has_racy_timestamp(istate)) &&
-           !write_index(istate, lockfile->fd))
-               commit_locked_index(lockfile);
-       else
+           write_locked_index(istate, lockfile, COMMIT_LOCK))
                rollback_lock_file(lockfile);
 }
 
-int write_index(struct index_state *istate, int newfd)
+static int do_write_index(struct index_state *istate, int newfd)
 {
        git_SHA_CTX c;
        struct cache_header hdr;
@@ -1877,6 +1879,47 @@ int write_index(struct index_state *istate, int newfd)
        return 0;
 }
 
+void set_alternate_index_output(const char *name)
+{
+       alternate_index_output = name;
+}
+
+static int commit_locked_index(struct lock_file *lk)
+{
+       if (alternate_index_output) {
+               if (lk->fd >= 0 && close_lock_file(lk))
+                       return -1;
+               if (rename(lk->filename, alternate_index_output))
+                       return -1;
+               lk->filename[0] = 0;
+               return 0;
+       } else {
+               return commit_lock_file(lk);
+       }
+}
+
+static int do_write_locked_index(struct index_state *istate, struct lock_file *lock,
+                                unsigned flags)
+{
+       int ret = do_write_index(istate, lock->fd);
+       if (ret)
+               return ret;
+       assert((flags & (COMMIT_LOCK | CLOSE_LOCK)) !=
+              (COMMIT_LOCK | CLOSE_LOCK));
+       if (flags & COMMIT_LOCK)
+               return commit_locked_index(lock);
+       else if (flags & CLOSE_LOCK)
+               return close_lock_file(lock);
+       else
+               return ret;
+}
+
+int write_locked_index(struct index_state *istate, struct lock_file *lock,
+                      unsigned flags)
+{
+       return do_write_locked_index(istate, lock, flags);
+}
+
 /*
  * Read the index file that is potentially unmerged into given
  * index_state, dropping any unmerged entries.  Returns true if