| #ifndef PACK_OBJECTS_H |
| #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) |
| |
| #define OE_DFS_STATE_BITS 2 |
| #define OE_DEPTH_BITS 12 |
| #define OE_IN_PACK_BITS 10 |
| #define OE_Z_DELTA_BITS 20 |
| /* |
| * Note that oe_set_size() becomes expensive when the given size is |
| * above this limit. Don't lower it too much. |
| */ |
| #define OE_SIZE_BITS 31 |
| #define OE_DELTA_SIZE_BITS 23 |
| |
| /* |
| * State flags for depth-first search used for analyzing delta cycles. |
| * |
| * The depth is measured in delta-links to the base (so if A is a delta |
| * against B, then A has a depth of 1, and B a depth of 0). |
| */ |
| enum dfs_state { |
| DFS_NONE = 0, |
| DFS_ACTIVE, |
| DFS_DONE, |
| DFS_NUM_STATES |
| }; |
| |
| /* |
| * The size of struct nearly determines pack-objects's memory |
| * consumption. This struct is packed tight for that reason. When you |
| * add or reorder something in this struct, think a bit about this. |
| * |
| * basic object info |
| * ----------------- |
| * idx.oid is filled up before delta searching starts. idx.crc32 is |
| * only valid after the object is written out and will be used for |
| * generating the index. idx.offset will be both gradually set and |
| * used in writing phase (base objects get offset first, then deltas |
| * refer to them) |
| * |
| * "size" is the uncompressed object size. Compressed size of the raw |
| * data for an object in a pack is not stored anywhere but is computed |
| * and made available when reverse .idx is made. Note that when a |
| * delta is reused, "size" is the uncompressed _delta_ size, not the |
| * canonical one after the delta has been applied. |
| * |
| * "hash" contains a path name hash which is used for sorting the |
| * delta list and also during delta searching. Once prepare_pack() |
| * returns it's no longer needed. |
| * |
| * source pack info |
| * ---------------- |
| * The (in_pack, in_pack_offset) tuple contains the location of the |
| * object in the source pack. in_pack_header_size allows quickly |
| * skipping the header and going straight to the zlib stream. |
| * |
| * "type" and "in_pack_type" both describe object type. in_pack_type |
| * may contain a delta type, while type is always the canonical type. |
| * |
| * deltas |
| * ------ |
| * Delta links (delta, delta_child and delta_sibling) are created to |
| * reflect that delta graph from the source pack then updated or added |
| * during delta searching phase when we find better deltas. |
| * |
| * delta_child and delta_sibling are last needed in |
| * compute_write_order(). "delta" and "delta_size" must remain valid |
| * at object writing phase in case the delta is not cached. |
| * |
| * If a delta is cached in memory and is compressed, delta_data points |
| * to the data and z_delta_size contains the compressed size. If it's |
| * uncompressed [1], z_delta_size must be zero. delta_size is always |
| * the uncompressed size and must be valid even if the delta is not |
| * cached. |
| * |
| * [1] during try_delta phase we don't bother with compressing because |
| * the delta could be quickly replaced with a better one. |
| */ |
| struct object_entry { |
| struct pack_idx_entry idx; |
| void *delta_data; /* cached delta (uncompressed) */ |
| off_t in_pack_offset; |
| uint32_t hash; /* name hint hash */ |
| unsigned size_:OE_SIZE_BITS; |
| unsigned size_valid:1; |
| uint32_t delta_idx; /* delta base object */ |
| uint32_t delta_child_idx; /* deltified objects who bases me */ |
| uint32_t delta_sibling_idx; /* other deltified objects who |
| * uses the same base as me |
| */ |
| 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 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 |
| * objects against. |
| */ |
| unsigned tagged:1; /* near the very tip of refs */ |
| unsigned filled:1; /* assigned write-order */ |
| unsigned dfs_state:OE_DFS_STATE_BITS; |
| 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: 9 bits |
| * |
| * and on 32-bit (gcc) |
| * |
| * size: 76, bit_padding: 9 bits |
| */ |
| }; |
| |
| struct packing_data { |
| struct repository *repo; |
| struct object_entry *objects; |
| uint32_t nr_objects, nr_alloc; |
| |
| int32_t *index; |
| 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 |
| * sizes. if in_pack_by_idx is allocated, oe_in_pack() returns |
| * the pack of an object using in_pack_idx field. If not, |
| * in_pack[] array is used the same way as in_pack_pos[] |
| */ |
| 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 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 struct object_id *oid); |
| |
| struct object_entry *packlist_find(struct packing_data *pdata, |
| const struct object_id *oid); |
| |
| static inline uint32_t pack_name_hash(const char *name) |
| { |
| uint32_t c, hash = 0; |
| |
| if (!name) |
| return 0; |
| |
| /* |
| * This effectively just creates a sortable number from the |
| * last sixteen non-whitespace characters. Last characters |
| * count "most", so things that end in ".c" sort together. |
| */ |
| while ((c = *name++) != 0) { |
| if (isspace(c)) |
| continue; |
| hash = (hash >> 2) + (c << 24); |
| } |
| return hash; |
| } |
| |
| static inline enum object_type oe_type(const struct object_entry *e) |
| { |
| return e->type_valid ? e->type_ : OBJ_BAD; |
| } |
| |
| static inline void oe_set_type(struct object_entry *e, |
| enum object_type type) |
| { |
| if (type >= OBJ_ANY) |
| BUG("OBJ_ANY cannot be set in pack-objects code"); |
| |
| e->type_valid = type >= OBJ_NONE; |
| e->type_ = (unsigned)type; |
| } |
| |
| static inline unsigned int oe_in_pack_pos(const struct packing_data *pack, |
| const struct object_entry *e) |
| { |
| return pack->in_pack_pos[e - pack->objects]; |
| } |
| |
| static inline void oe_set_in_pack_pos(const struct packing_data *pack, |
| const struct object_entry *e, |
| unsigned int pos) |
| { |
| pack->in_pack_pos[e - pack->objects] = pos; |
| } |
| |
| static inline struct packed_git *oe_in_pack(const struct packing_data *pack, |
| const struct object_entry *e) |
| { |
| if (pack->in_pack_by_idx) |
| return pack->in_pack_by_idx[e->in_pack_idx]; |
| else |
| return pack->in_pack[e - pack->objects]; |
| } |
| |
| 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 (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; |
| } |
| |
| void oe_set_delta_ext(struct packing_data *pack, |
| struct object_entry *e, |
| const struct object_id *oid); |
| |
| 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_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 |