]> git.ipfire.org Git - thirdparty/git.git/blobdiff - pack-objects.h
git-worktree.txt: discuss branch-based vs. throwaway worktrees
[thirdparty/git.git] / pack-objects.h
index edf74dabddfdb2b67bad803d1c898e93a3af4d8b..9d88e3e518f06245ae6278e14efd14a21e1b44ba 100644 (file)
@@ -2,6 +2,10 @@
 #define PACK_OBJECTS_H
 
 #include "object-store.h"
+#include "thread-utils.h"
+#include "pack.h"
+
+struct repository;
 
 #define DEFAULT_DELTA_CACHE_SIZE (256 * 1024 * 1024)
 
@@ -14,7 +18,7 @@
  * above this limit. Don't lower it too much.
  */
 #define OE_SIZE_BITS           31
-#define OE_DELTA_SIZE_BITS     20
+#define OE_DELTA_SIZE_BITS     23
 
 /*
  * State flags for depth-first search used for analyzing delta cycles.
@@ -94,12 +98,14 @@ struct object_entry {
                                     */
        unsigned delta_size_:OE_DELTA_SIZE_BITS; /* delta data size (uncompressed) */
        unsigned delta_size_valid:1;
+       unsigned char in_pack_header_size;
        unsigned in_pack_idx:OE_IN_PACK_BITS;   /* already in pack */
        unsigned z_delta_size:OE_Z_DELTA_BITS;
        unsigned type_valid:1;
-       unsigned type_:TYPE_BITS;
        unsigned no_try_delta:1;
+       unsigned type_:TYPE_BITS;
        unsigned in_pack_type:TYPE_BITS; /* could be delta */
+
        unsigned preferred_base:1; /*
                                    * we do not pack this, but is available
                                    * to be used as the base object to delta
@@ -108,21 +114,22 @@ struct object_entry {
        unsigned tagged:1; /* near the very tip of refs */
        unsigned filled:1; /* assigned write-order */
        unsigned dfs_state:OE_DFS_STATE_BITS;
-       unsigned char in_pack_header_size;
        unsigned depth:OE_DEPTH_BITS;
+       unsigned ext_base:1; /* delta_idx points outside packlist */
 
        /*
         * pahole results on 64-bit linux (gcc and clang)
         *
-        *   size: 80, bit_padding: 20 bits, holes: 8 bits
+        *   size: 80, bit_padding: 9 bits
         *
         * and on 32-bit (gcc)
         *
-        *   size: 76, bit_padding: 20 bits, holes: 8 bits
+        *   size: 76, bit_padding: 9 bits
         */
 };
 
 struct packing_data {
+       struct repository *repo;
        struct object_entry *objects;
        uint32_t nr_objects, nr_alloc;
 
@@ -130,6 +137,7 @@ struct packing_data {
        uint32_t index_size;
 
        unsigned int *in_pack_pos;
+       unsigned long *delta_size;
 
        /*
         * Only one of these can be non-NULL and they have different
@@ -140,17 +148,45 @@ struct packing_data {
        struct packed_git **in_pack_by_idx;
        struct packed_git **in_pack;
 
+       /*
+        * During packing with multiple threads, protect the in-core
+        * object database from concurrent accesses.
+        */
+       pthread_mutex_t odb_lock;
+
+       /*
+        * This list contains entries for bases which we know the other side
+        * has (e.g., via reachability bitmaps), but which aren't in our
+        * "objects" list.
+        */
+       struct object_entry *ext_bases;
+       uint32_t nr_ext, alloc_ext;
+
        uintmax_t oe_size_limit;
+       uintmax_t oe_delta_size_limit;
+
+       /* delta islands */
+       unsigned int *tree_depth;
+       unsigned char *layer;
 };
 
-void prepare_packing_data(struct packing_data *pdata);
+void prepare_packing_data(struct repository *r, struct packing_data *pdata);
+
+/* Protect access to object database */
+static inline void packing_data_lock(struct packing_data *pdata)
+{
+       pthread_mutex_lock(&pdata->odb_lock);
+}
+static inline void packing_data_unlock(struct packing_data *pdata)
+{
+       pthread_mutex_unlock(&pdata->odb_lock);
+}
+
 struct object_entry *packlist_alloc(struct packing_data *pdata,
-                                   const unsigned char *sha1,
-                                   uint32_t index_pos);
+                                   const struct object_id *oid);
 
 struct object_entry *packlist_find(struct packing_data *pdata,
-                                  const unsigned char *sha1,
-                                  uint32_t *index_pos);
+                                  const struct object_id *oid);
 
 static inline uint32_t pack_name_hash(const char *name)
 {
@@ -209,27 +245,39 @@ static inline struct packed_git *oe_in_pack(const struct packing_data *pack,
                return pack->in_pack[e - pack->objects];
 }
 
-void oe_map_new_pack(struct packing_data *pack,
-                    struct packed_git *p);
+void oe_map_new_pack(struct packing_data *pack);
+
 static inline void oe_set_in_pack(struct packing_data *pack,
                                  struct object_entry *e,
                                  struct packed_git *p)
 {
-       if (!p->index)
-               oe_map_new_pack(pack, p);
-       if (pack->in_pack_by_idx)
-               e->in_pack_idx = p->index;
-       else
-               pack->in_pack[e - pack->objects] = p;
+       if (pack->in_pack_by_idx) {
+               if (p->index) {
+                       e->in_pack_idx = p->index;
+                       return;
+               }
+               /*
+                * We're accessing packs by index, but this pack doesn't have
+                * an index (e.g., because it was added since we created the
+                * in_pack_by_idx array). Bail to oe_map_new_pack(), which
+                * will convert us to using the full in_pack array, and then
+                * fall through to our in_pack handling.
+                */
+               oe_map_new_pack(pack);
+       }
+       pack->in_pack[e - pack->objects] = p;
 }
 
 static inline struct object_entry *oe_delta(
                const struct packing_data *pack,
                const struct object_entry *e)
 {
-       if (e->delta_idx)
+       if (!e->delta_idx)
+               return NULL;
+       if (e->ext_base)
+               return &pack->ext_bases[e->delta_idx - 1];
+       else
                return &pack->objects[e->delta_idx - 1];
-       return NULL;
 }
 
 static inline void oe_set_delta(struct packing_data *pack,
@@ -242,6 +290,10 @@ static inline void oe_set_delta(struct packing_data *pack,
                e->delta_idx = 0;
 }
 
+void oe_set_delta_ext(struct packing_data *pack,
+                     struct object_entry *e,
+                     const struct object_id *oid);
+
 static inline struct object_entry *oe_delta_child(
                const struct packing_data *pack,
                const struct object_entry *e)
@@ -332,18 +384,68 @@ static inline unsigned long oe_delta_size(struct packing_data *pack,
 {
        if (e->delta_size_valid)
                return e->delta_size_;
-       return oe_size(pack, e);
+
+       /*
+        * pack->delta_size[] can't be NULL because oe_set_delta_size()
+        * must have been called when a new delta is saved with
+        * oe_set_delta().
+        * If oe_delta() returns NULL (i.e. default state, which means
+        * delta_size_valid is also false), then the caller must never
+        * call oe_delta_size().
+        */
+       return pack->delta_size[e - pack->objects];
 }
 
 static inline void oe_set_delta_size(struct packing_data *pack,
                                     struct object_entry *e,
                                     unsigned long size)
 {
-       e->delta_size_ = size;
-       e->delta_size_valid = e->delta_size_ == size;
-       if (!e->delta_size_valid && size != oe_size(pack, e))
-               BUG("this can only happen in check_object() "
-                   "where delta size is the same as entry size");
+       if (size < pack->oe_delta_size_limit) {
+               e->delta_size_ = size;
+               e->delta_size_valid = 1;
+       } else {
+               packing_data_lock(pack);
+               if (!pack->delta_size)
+                       ALLOC_ARRAY(pack->delta_size, pack->nr_alloc);
+               packing_data_unlock(pack);
+
+               pack->delta_size[e - pack->objects] = size;
+               e->delta_size_valid = 0;
+       }
+}
+
+static inline unsigned int oe_tree_depth(struct packing_data *pack,
+                                        struct object_entry *e)
+{
+       if (!pack->tree_depth)
+               return 0;
+       return pack->tree_depth[e - pack->objects];
+}
+
+static inline void oe_set_tree_depth(struct packing_data *pack,
+                                    struct object_entry *e,
+                                    unsigned int tree_depth)
+{
+       if (!pack->tree_depth)
+               CALLOC_ARRAY(pack->tree_depth, pack->nr_alloc);
+       pack->tree_depth[e - pack->objects] = tree_depth;
+}
+
+static inline unsigned char oe_layer(struct packing_data *pack,
+                                    struct object_entry *e)
+{
+       if (!pack->layer)
+               return 0;
+       return pack->layer[e - pack->objects];
+}
+
+static inline void oe_set_layer(struct packing_data *pack,
+                               struct object_entry *e,
+                               unsigned char layer)
+{
+       if (!pack->layer)
+               CALLOC_ARRAY(pack->layer, pack->nr_alloc);
+       pack->layer[e - pack->objects] = layer;
 }
 
 #endif