multi-pack-index: implement 'expire' subcommand
[gitweb.git] / midx.c
diff --git a/midx.c b/midx.c
index 8b8faec35afbdc272c8838e3f238cc034c4938a4..9b0b4c152031007059092a2a6e23bf23cb09127a 100644 (file)
--- a/midx.c
+++ b/midx.c
@@ -34,6 +34,8 @@
 #define MIDX_CHUNK_LARGE_OFFSET_WIDTH (sizeof(uint64_t))
 #define MIDX_LARGE_OFFSET_NEEDED 0x80000000
 
+#define PACK_EXPIRED UINT_MAX
+
 static char *get_midx_filename(const char *object_dir)
 {
        return xstrfmt("%s/pack/multi-pack-index", object_dir);
@@ -192,10 +194,8 @@ void close_midx(struct multi_pack_index *m)
        m->fd = -1;
 
        for (i = 0; i < m->num_packs; i++) {
-               if (m->packs[i]) {
-                       close_pack(m->packs[i]);
-                       free(m->packs[i]);
-               }
+               if (m->packs[i])
+                       m->packs[i]->multi_pack_index = 0;
        }
        FREE_AND_NULL(m->packs);
        FREE_AND_NULL(m->pack_names);
@@ -204,6 +204,7 @@ void close_midx(struct multi_pack_index *m)
 int prepare_midx_pack(struct repository *r, struct multi_pack_index *m, uint32_t pack_int_id)
 {
        struct strbuf pack_name = STRBUF_INIT;
+       struct packed_git *p;
 
        if (pack_int_id >= m->num_packs)
                die(_("bad pack-int-id: %u (%u total packs)"),
@@ -215,9 +216,18 @@ int prepare_midx_pack(struct repository *r, struct multi_pack_index *m, uint32_t
        strbuf_addf(&pack_name, "%s/pack/%s", m->object_dir,
                    m->pack_names[pack_int_id]);
 
-       m->packs[pack_int_id] = add_packed_git(pack_name.buf, pack_name.len, m->local);
+       p = add_packed_git(pack_name.buf, pack_name.len, m->local);
        strbuf_release(&pack_name);
-       return !m->packs[pack_int_id];
+
+       if (!p)
+               return 1;
+
+       p->multi_pack_index = 1;
+       m->packs[pack_int_id] = p;
+       install_packed_git(r, p);
+       list_add_tail(&p->mru, &r->objects->packed_git_mru);
+
+       return 0;
 }
 
 int bsearch_midx(const struct object_id *oid, struct multi_pack_index *m, uint32_t *result)
@@ -419,13 +429,24 @@ static size_t write_midx_header(struct hashfile *f,
        return MIDX_HEADER_SIZE;
 }
 
+struct pack_info {
+       uint32_t orig_pack_int_id;
+       char *pack_name;
+       struct packed_git *p;
+       unsigned expired : 1;
+};
+
+static int pack_info_compare(const void *_a, const void *_b)
+{
+       struct pack_info *a = (struct pack_info *)_a;
+       struct pack_info *b = (struct pack_info *)_b;
+       return strcmp(a->pack_name, b->pack_name);
+}
+
 struct pack_list {
-       struct packed_git **list;
-       char **names;
+       struct pack_info *info;
        uint32_t nr;
-       uint32_t alloc_list;
-       uint32_t alloc_names;
-       size_t pack_name_concat_len;
+       uint32_t alloc;
        struct multi_pack_index *m;
 };
 
@@ -438,67 +459,33 @@ static void add_pack_to_midx(const char *full_path, size_t full_path_len,
                if (packs->m && midx_contains_pack(packs->m, file_name))
                        return;
 
-               ALLOC_GROW(packs->list, packs->nr + 1, packs->alloc_list);
-               ALLOC_GROW(packs->names, packs->nr + 1, packs->alloc_names);
+               ALLOC_GROW(packs->info, packs->nr + 1, packs->alloc);
 
-               packs->list[packs->nr] = add_packed_git(full_path,
-                                                       full_path_len,
-                                                       0);
+               packs->info[packs->nr].p = add_packed_git(full_path,
+                                                         full_path_len,
+                                                         0);
 
-               if (!packs->list[packs->nr]) {
+               if (!packs->info[packs->nr].p) {
                        warning(_("failed to add packfile '%s'"),
                                full_path);
                        return;
                }
 
-               if (open_pack_index(packs->list[packs->nr])) {
+               if (open_pack_index(packs->info[packs->nr].p)) {
                        warning(_("failed to open pack-index '%s'"),
                                full_path);
-                       close_pack(packs->list[packs->nr]);
-                       FREE_AND_NULL(packs->list[packs->nr]);
+                       close_pack(packs->info[packs->nr].p);
+                       FREE_AND_NULL(packs->info[packs->nr].p);
                        return;
                }
 
-               packs->names[packs->nr] = xstrdup(file_name);
-               packs->pack_name_concat_len += strlen(file_name) + 1;
+               packs->info[packs->nr].pack_name = xstrdup(file_name);
+               packs->info[packs->nr].orig_pack_int_id = packs->nr;
+               packs->info[packs->nr].expired = 0;
                packs->nr++;
        }
 }
 
-struct pack_pair {
-       uint32_t pack_int_id;
-       char *pack_name;
-};
-
-static int pack_pair_compare(const void *_a, const void *_b)
-{
-       struct pack_pair *a = (struct pack_pair *)_a;
-       struct pack_pair *b = (struct pack_pair *)_b;
-       return strcmp(a->pack_name, b->pack_name);
-}
-
-static void sort_packs_by_name(char **pack_names, uint32_t nr_packs, uint32_t *perm)
-{
-       uint32_t i;
-       struct pack_pair *pairs;
-
-       ALLOC_ARRAY(pairs, nr_packs);
-
-       for (i = 0; i < nr_packs; i++) {
-               pairs[i].pack_int_id = i;
-               pairs[i].pack_name = pack_names[i];
-       }
-
-       QSORT(pairs, nr_packs, pack_pair_compare);
-
-       for (i = 0; i < nr_packs; i++) {
-               pack_names[i] = pairs[i].pack_name;
-               perm[pairs[i].pack_int_id] = i;
-       }
-
-       free(pairs);
-}
-
 struct pack_midx_entry {
        struct object_id oid;
        uint32_t pack_int_id;
@@ -524,7 +511,6 @@ static int midx_oid_compare(const void *_a, const void *_b)
 }
 
 static int nth_midxed_pack_midx_entry(struct multi_pack_index *m,
-                                     uint32_t *pack_perm,
                                      struct pack_midx_entry *e,
                                      uint32_t pos)
 {
@@ -532,7 +518,7 @@ static int nth_midxed_pack_midx_entry(struct multi_pack_index *m,
                return 1;
 
        nth_midxed_object_oid(&e->oid, m, pos);
-       e->pack_int_id = pack_perm[nth_midxed_pack_int_id(m, pos)];
+       e->pack_int_id = nth_midxed_pack_int_id(m, pos);
        e->offset = nth_midxed_offset(m, pos);
 
        /* consider objects in midx to be from "old" packs */
@@ -566,8 +552,7 @@ static void fill_pack_entry(uint32_t pack_int_id,
  * of a packfile containing the object).
  */
 static struct pack_midx_entry *get_sorted_entries(struct multi_pack_index *m,
-                                                 struct packed_git **p,
-                                                 uint32_t *perm,
+                                                 struct pack_info *info,
                                                  uint32_t nr_packs,
                                                  uint32_t *nr_objects)
 {
@@ -578,7 +563,7 @@ static struct pack_midx_entry *get_sorted_entries(struct multi_pack_index *m,
        uint32_t start_pack = m ? m->num_packs : 0;
 
        for (cur_pack = start_pack; cur_pack < nr_packs; cur_pack++)
-               total_objects += p[cur_pack]->num_objects;
+               total_objects += info[cur_pack].p->num_objects;
 
        /*
         * As we de-duplicate by fanout value, we expect the fanout
@@ -603,7 +588,7 @@ static struct pack_midx_entry *get_sorted_entries(struct multi_pack_index *m,
 
                        for (cur_object = start; cur_object < end; cur_object++) {
                                ALLOC_GROW(entries_by_fanout, nr_fanout + 1, alloc_fanout);
-                               nth_midxed_pack_midx_entry(m, perm,
+                               nth_midxed_pack_midx_entry(m,
                                                           &entries_by_fanout[nr_fanout],
                                                           cur_object);
                                nr_fanout++;
@@ -614,12 +599,12 @@ static struct pack_midx_entry *get_sorted_entries(struct multi_pack_index *m,
                        uint32_t start = 0, end;
 
                        if (cur_fanout)
-                               start = get_pack_fanout(p[cur_pack], cur_fanout - 1);
-                       end = get_pack_fanout(p[cur_pack], cur_fanout);
+                               start = get_pack_fanout(info[cur_pack].p, cur_fanout - 1);
+                       end = get_pack_fanout(info[cur_pack].p, cur_fanout);
 
                        for (cur_object = start; cur_object < end; cur_object++) {
                                ALLOC_GROW(entries_by_fanout, nr_fanout + 1, alloc_fanout);
-                               fill_pack_entry(perm[cur_pack], p[cur_pack], cur_object, &entries_by_fanout[nr_fanout]);
+                               fill_pack_entry(cur_pack, info[cur_pack].p, cur_object, &entries_by_fanout[nr_fanout]);
                                nr_fanout++;
                        }
                }
@@ -648,7 +633,7 @@ static struct pack_midx_entry *get_sorted_entries(struct multi_pack_index *m,
 }
 
 static size_t write_midx_pack_names(struct hashfile *f,
-                                   char **pack_names,
+                                   struct pack_info *info,
                                    uint32_t num_packs)
 {
        uint32_t i;
@@ -656,14 +641,18 @@ static size_t write_midx_pack_names(struct hashfile *f,
        size_t written = 0;
 
        for (i = 0; i < num_packs; i++) {
-               size_t writelen = strlen(pack_names[i]) + 1;
+               size_t writelen;
+
+               if (info[i].expired)
+                       continue;
 
-               if (i && strcmp(pack_names[i], pack_names[i - 1]) <= 0)
+               if (i && strcmp(info[i].pack_name, info[i - 1].pack_name) <= 0)
                        BUG("incorrect pack-file order: %s before %s",
-                           pack_names[i - 1],
-                           pack_names[i]);
+                           info[i - 1].pack_name,
+                           info[i].pack_name);
 
-               hashwrite(f, pack_names[i], writelen);
+               writelen = strlen(info[i].pack_name) + 1;
+               hashwrite(f, info[i].pack_name, writelen);
                written += writelen;
        }
 
@@ -734,6 +723,7 @@ static size_t write_midx_oid_lookup(struct hashfile *f, unsigned char hash_len,
 }
 
 static size_t write_midx_object_offsets(struct hashfile *f, int large_offset_needed,
+                                       uint32_t *perm,
                                        struct pack_midx_entry *objects, uint32_t nr_objects)
 {
        struct pack_midx_entry *list = objects;
@@ -743,7 +733,12 @@ static size_t write_midx_object_offsets(struct hashfile *f, int large_offset_nee
        for (i = 0; i < nr_objects; i++) {
                struct pack_midx_entry *obj = list++;
 
-               hashwrite_be32(f, obj->pack_int_id);
+               if (perm[obj->pack_int_id] == PACK_EXPIRED)
+                       BUG("object %s is in an expired pack with int-id %d",
+                           oid_to_hex(&obj->oid),
+                           obj->pack_int_id);
+
+               hashwrite_be32(f, perm[obj->pack_int_id]);
 
                if (large_offset_needed && obj->offset >> 31)
                        hashwrite_be32(f, MIDX_LARGE_OFFSET_NEEDED | nr_large_offset++);
@@ -789,7 +784,8 @@ static size_t write_midx_large_offsets(struct hashfile *f, uint32_t nr_large_off
        return written;
 }
 
-int write_midx_file(const char *object_dir)
+static int write_midx_internal(const char *object_dir, struct multi_pack_index *m,
+                              struct string_list *packs_to_drop)
 {
        unsigned char cur_chunk, num_chunks = 0;
        char *midx_name;
@@ -804,6 +800,9 @@ int write_midx_file(const char *object_dir)
        uint32_t nr_entries, num_large_offsets = 0;
        struct pack_midx_entry *entries = NULL;
        int large_offsets_needed = 0;
+       int pack_name_concat_len = 0;
+       int dropped_packs = 0;
+       int result = 0;
 
        midx_name = get_midx_filename(object_dir);
        if (safe_create_leading_directories(midx_name)) {
@@ -812,42 +811,34 @@ int write_midx_file(const char *object_dir)
                          midx_name);
        }
 
-       packs.m = load_multi_pack_index(object_dir, 1);
+       if (m)
+               packs.m = m;
+       else
+               packs.m = load_multi_pack_index(object_dir, 1);
 
        packs.nr = 0;
-       packs.alloc_list = packs.m ? packs.m->num_packs : 16;
-       packs.alloc_names = packs.alloc_list;
-       packs.list = NULL;
-       packs.names = NULL;
-       packs.pack_name_concat_len = 0;
-       ALLOC_ARRAY(packs.list, packs.alloc_list);
-       ALLOC_ARRAY(packs.names, packs.alloc_names);
+       packs.alloc = packs.m ? packs.m->num_packs : 16;
+       packs.info = NULL;
+       ALLOC_ARRAY(packs.info, packs.alloc);
 
        if (packs.m) {
                for (i = 0; i < packs.m->num_packs; i++) {
-                       ALLOC_GROW(packs.list, packs.nr + 1, packs.alloc_list);
-                       ALLOC_GROW(packs.names, packs.nr + 1, packs.alloc_names);
+                       ALLOC_GROW(packs.info, packs.nr + 1, packs.alloc);
 
-                       packs.list[packs.nr] = NULL;
-                       packs.names[packs.nr] = xstrdup(packs.m->pack_names[i]);
-                       packs.pack_name_concat_len += strlen(packs.names[packs.nr]) + 1;
+                       packs.info[packs.nr].orig_pack_int_id = i;
+                       packs.info[packs.nr].pack_name = xstrdup(packs.m->pack_names[i]);
+                       packs.info[packs.nr].p = NULL;
+                       packs.info[packs.nr].expired = 0;
                        packs.nr++;
                }
        }
 
        for_each_file_in_pack_dir(object_dir, add_pack_to_midx, &packs);
 
-       if (packs.m && packs.nr == packs.m->num_packs)
+       if (packs.m && packs.nr == packs.m->num_packs && !packs_to_drop)
                goto cleanup;
 
-       if (packs.pack_name_concat_len % MIDX_CHUNK_ALIGNMENT)
-               packs.pack_name_concat_len += MIDX_CHUNK_ALIGNMENT -
-                                             (packs.pack_name_concat_len % MIDX_CHUNK_ALIGNMENT);
-
-       ALLOC_ARRAY(pack_perm, packs.nr);
-       sort_packs_by_name(packs.names, packs.nr, pack_perm);
-
-       entries = get_sorted_entries(packs.m, packs.list, pack_perm, packs.nr, &nr_entries);
+       entries = get_sorted_entries(packs.m, packs.info, packs.nr, &nr_entries);
 
        for (i = 0; i < nr_entries; i++) {
                if (entries[i].offset > 0x7fffffff)
@@ -856,6 +847,61 @@ int write_midx_file(const char *object_dir)
                        large_offsets_needed = 1;
        }
 
+       QSORT(packs.info, packs.nr, pack_info_compare);
+
+       if (packs_to_drop && packs_to_drop->nr) {
+               int drop_index = 0;
+               int missing_drops = 0;
+
+               for (i = 0; i < packs.nr && drop_index < packs_to_drop->nr; i++) {
+                       int cmp = strcmp(packs.info[i].pack_name,
+                                        packs_to_drop->items[drop_index].string);
+
+                       if (!cmp) {
+                               drop_index++;
+                               packs.info[i].expired = 1;
+                       } else if (cmp > 0) {
+                               error(_("did not see pack-file %s to drop"),
+                                     packs_to_drop->items[drop_index].string);
+                               drop_index++;
+                               missing_drops++;
+                               i--;
+                       } else {
+                               packs.info[i].expired = 0;
+                       }
+               }
+
+               if (missing_drops) {
+                       result = 1;
+                       goto cleanup;
+               }
+       }
+
+       /*
+        * pack_perm stores a permutation between pack-int-ids from the
+        * previous multi-pack-index to the new one we are writing:
+        *
+        * pack_perm[old_id] = new_id
+        */
+       ALLOC_ARRAY(pack_perm, packs.nr);
+       for (i = 0; i < packs.nr; i++) {
+               if (packs.info[i].expired) {
+                       dropped_packs++;
+                       pack_perm[packs.info[i].orig_pack_int_id] = PACK_EXPIRED;
+               } else {
+                       pack_perm[packs.info[i].orig_pack_int_id] = i - dropped_packs;
+               }
+       }
+
+       for (i = 0; i < packs.nr; i++) {
+               if (!packs.info[i].expired)
+                       pack_name_concat_len += strlen(packs.info[i].pack_name) + 1;
+       }
+
+       if (pack_name_concat_len % MIDX_CHUNK_ALIGNMENT)
+               pack_name_concat_len += MIDX_CHUNK_ALIGNMENT -
+                                       (pack_name_concat_len % MIDX_CHUNK_ALIGNMENT);
+
        hold_lock_file_for_update(&lk, midx_name, LOCK_DIE_ON_ERROR);
        f = hashfd(lk.tempfile->fd, lk.tempfile->filename.buf);
        FREE_AND_NULL(midx_name);
@@ -866,14 +912,14 @@ int write_midx_file(const char *object_dir)
        cur_chunk = 0;
        num_chunks = large_offsets_needed ? 5 : 4;
 
-       written = write_midx_header(f, num_chunks, packs.nr);
+       written = write_midx_header(f, num_chunks, packs.nr - dropped_packs);
 
        chunk_ids[cur_chunk] = MIDX_CHUNKID_PACKNAMES;
        chunk_offsets[cur_chunk] = written + (num_chunks + 1) * MIDX_CHUNKLOOKUP_WIDTH;
 
        cur_chunk++;
        chunk_ids[cur_chunk] = MIDX_CHUNKID_OIDFANOUT;
-       chunk_offsets[cur_chunk] = chunk_offsets[cur_chunk - 1] + packs.pack_name_concat_len;
+       chunk_offsets[cur_chunk] = chunk_offsets[cur_chunk - 1] + pack_name_concat_len;
 
        cur_chunk++;
        chunk_ids[cur_chunk] = MIDX_CHUNKID_OIDLOOKUP;
@@ -921,7 +967,7 @@ int write_midx_file(const char *object_dir)
 
                switch (chunk_ids[i]) {
                        case MIDX_CHUNKID_PACKNAMES:
-                               written += write_midx_pack_names(f, packs.names, packs.nr);
+                               written += write_midx_pack_names(f, packs.info, packs.nr);
                                break;
 
                        case MIDX_CHUNKID_OIDFANOUT:
@@ -933,7 +979,7 @@ int write_midx_file(const char *object_dir)
                                break;
 
                        case MIDX_CHUNKID_OBJECTOFFSETS:
-                               written += write_midx_object_offsets(f, large_offsets_needed, entries, nr_entries);
+                               written += write_midx_object_offsets(f, large_offsets_needed, pack_perm, entries, nr_entries);
                                break;
 
                        case MIDX_CHUNKID_LARGEOFFSETS:
@@ -956,19 +1002,23 @@ int write_midx_file(const char *object_dir)
 
 cleanup:
        for (i = 0; i < packs.nr; i++) {
-               if (packs.list[i]) {
-                       close_pack(packs.list[i]);
-                       free(packs.list[i]);
+               if (packs.info[i].p) {
+                       close_pack(packs.info[i].p);
+                       free(packs.info[i].p);
                }
-               free(packs.names[i]);
+               free(packs.info[i].pack_name);
        }
 
-       free(packs.list);
-       free(packs.names);
+       free(packs.info);
        free(entries);
        free(pack_perm);
        free(midx_name);
-       return 0;
+       return result;
+}
+
+int write_midx_file(const char *object_dir)
+{
+       return write_midx_internal(object_dir, NULL, NULL);
 }
 
 void clear_midx_file(struct repository *r)
@@ -1132,3 +1182,47 @@ int verify_midx_file(struct repository *r, const char *object_dir)
 
        return verify_midx_error;
 }
+
+int expire_midx_packs(struct repository *r, const char *object_dir)
+{
+       uint32_t i, *count, result = 0;
+       struct string_list packs_to_drop = STRING_LIST_INIT_DUP;
+       struct multi_pack_index *m = load_multi_pack_index(object_dir, 1);
+
+       if (!m)
+               return 0;
+
+       count = xcalloc(m->num_packs, sizeof(uint32_t));
+       for (i = 0; i < m->num_objects; i++) {
+               int pack_int_id = nth_midxed_pack_int_id(m, i);
+               count[pack_int_id]++;
+       }
+
+       for (i = 0; i < m->num_packs; i++) {
+               char *pack_name;
+
+               if (count[i])
+                       continue;
+
+               if (prepare_midx_pack(r, m, i))
+                       continue;
+
+               if (m->packs[i]->pack_keep)
+                       continue;
+
+               pack_name = xstrdup(m->packs[i]->pack_name);
+               close_pack(m->packs[i]);
+
+               string_list_insert(&packs_to_drop, m->pack_names[i]);
+               unlink_pack_path(pack_name, 0);
+               free(pack_name);
+       }
+
+       free(count);
+
+       if (packs_to_drop.nr)
+               result = write_midx_internal(object_dir, m, &packs_to_drop);
+
+       string_list_clear(&packs_to_drop, 0);
+       return result;
+}