diff options
author | Campbell Barton <ideasman42@gmail.com> | 2016-05-30 08:25:36 +0300 |
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committer | Campbell Barton <ideasman42@gmail.com> | 2016-05-30 09:18:24 +0300 |
commit | 53b60eed45098cdb5e0a6f4a05e242f5d6524635 (patch) | |
tree | a6fc111557c3beee2a3b17a2f2550232f004c562 /source/blender/blenlib/intern/array_store.c | |
parent | 11b0874db003fed55578e3a49d6c5377ac49902e (diff) |
Add BLI_array_store copy-on-write API
This supported in-memory de-duplication,
useful to avoid in-efficient memory use when storing multiple, similar arrays.
Diffstat (limited to 'source/blender/blenlib/intern/array_store.c')
-rw-r--r-- | source/blender/blenlib/intern/array_store.c | 1731 |
1 files changed, 1731 insertions, 0 deletions
diff --git a/source/blender/blenlib/intern/array_store.c b/source/blender/blenlib/intern/array_store.c new file mode 100644 index 00000000000..8cbabddb1af --- /dev/null +++ b/source/blender/blenlib/intern/array_store.c @@ -0,0 +1,1731 @@ +/* + * ***** BEGIN GPL LICENSE BLOCK ***** + * + * This program is free software; you can redistribute it and/or + * modify it under the terms of the GNU General Public License + * as published by the Free Software Foundation; either version 2 + * of the License, or (at your option) any later version. + * + * This program is distributed in the hope that it will be useful, + * but WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + * GNU General Public License for more details. + * + * You should have received a copy of the GNU General Public License + * along with this program; if not, write to the Free Software Foundation, + * Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA. + * + * ***** END GPL LICENSE BLOCK ***** + */ + +/** \file blender/blenlib/intern/array_store.c + * \ingroup bli + * \brief Array storage to minimize duplication. + * + * This is done by splitting arrays into chunks and using copy-on-write (COW), + * to de-duplicate chunks, + * from the users perspective this is an implementation detail. + * + * + * Overview + * ======== + * + * + * Data Structure + * -------------- + * + * This diagram is an overview of the structure of a single array-store. + * + * \note The only 2 structues here which are referenced externally are the. + * + * - BArrayStore: The whole array store. + * - BArrayState: Represents a single state (array) of data. + * These can be add using a reference state, while this could be considered the previous or parent state. + * no relationship is kept, so the caller is free to add any state from the same BArrayStore as a reference. + * + * <pre> + * <+> BArrayStore: root data-structure, + * | can store many 'states', which share memory. + * | + * | This can store many arrays, however they must share the same 'stride'. + * | Arrays of different types will need to use a new BArrayStore. + * | + * +- <+> states (Collection of BArrayState's): + * | | Each represents an array added by the user of this API. + * | | and references a chunk_list (each state is a chunk_list user). + * | | Note that the list order has no significance. + * | | + * | +- <+> chunk_list (BChunkList): + * | | The chunks that make up this state. + * | | Each state is a chunk_list user, + * | | avoids duplicating lists when there is no change between states. + * | | + * | +- chunk_refs (List of BChunkRef): Each chunk_ref links to a a BChunk. + * | Each reference is a chunk user, + * | avoids duplicating smaller chunks of memory found in multiple states. + * | + * +- info (BArrayInfo): + * | Sizes and offsets for this array-store. + * | Also caches some variables for reuse. + * | + * +- <+> memory (BArrayMemory): + * | Memory pools for storing BArrayStore data. + * | + * +- chunk_list (Pool of BChunkList): + * | All chunk_lists, (reference counted, used by BArrayState). + * | + * +- chunk_ref (Pool of BChunkRef): + * | All chunk_refs (link between BChunkList & BChunk). + * | + * +- chunks (Pool of BChunk): + * All chunks, (reference counted, used by BChunkList). + * These have their headers hashed for reuse so we can quickly check for duplicates. + * </pre> + * + * + * De-Duplication + * -------------- + * + * When creating a new state, a previous state can be given as a reference, + * matching chunks from this state are re-used in the new state. + * + * First matches at either end of the array are detected. + * For identical arrays this is all thats needed. + * + * De-duplication is performed on any remaining chunks, by hasing the first few bytes of the chunk + * (see: BCHUNK_HASH_TABLE_ACCUMULATE_STEPS). + * + * \note This is cached for reuse since the referenced data never changes. + * + * An array is created to store hash values at every 'stride', + * then stepped over to search for matching chunks. + * + * Once a match is found, there is a high chance next chunks match too, + * so this is checked to avoid performing so many hash-lookups. + * Otherwise new chunks are created. + */ + +#include <stdlib.h> +#include <string.h> + +#include "MEM_guardedalloc.h" + +#include "BLI_listbase.h" +#include "BLI_mempool.h" + +#include "BLI_strict_flags.h" + +#include "BLI_array_store.h" /* own include */ + +/* only for BLI_array_store_is_valid */ +#include "BLI_ghash.h" + +/** \name Defines + * + * Some of the logic for merging is quite involved, + * support disabling some parts of this. + * \{ */ + +/* Scan first chunks (happy path when beginning of the array matches). + * When the array is a perfect match, we can re-use the entire list. + * + * Note that disabling makes some tests fail that check for output-size. + */ +#define USE_FASTPATH_CHUNKS_FIRST + +/* Scan last chunks (happy path when end of the array matches). + * When the end of the array matches, we can quickly add these chunks. + * note that we will add contiguous matching chunks + * so this isn't as useful as USE_FASTPATH_CHUNKS_FIRST, + * however it avoids adding matching chunks into the lookup table, + * so creating the lookup table won't be as expensive. + */ +#ifdef USE_FASTPATH_CHUNKS_FIRST +# define USE_FASTPATH_CHUNKS_LAST +#endif + +/* For arrays of matching length, test that *enough* of the chunks are aligned, + * and simply step over both arrays, using matching chunks. + * This avoids overhead of using a lookup table for cases when we can assume they're mostly aligned. + */ +#define USE_ALIGN_CHUNKS_TEST + +/* Accumulate hashes from right to left so we can create a hash for the chunk-start. + * This serves to increase uniqueness and will help when there is many values which are the same. + */ +#define USE_HASH_TABLE_ACCUMULATE + +#ifdef USE_HASH_TABLE_ACCUMULATE +/* Number of times to propagate hashes back. + * Effectively a 'triangle-number'. + * so 4 -> 7, 5 -> 10, 6 -> 15... etc. + */ +# define BCHUNK_HASH_TABLE_ACCUMULATE_STEPS 4 +#else +/* How many items to hash (multiplied by stride) + */ +# define BCHUNK_HASH_LEN 4 +#endif + +/* Calculate the key once and reuse it + */ +#define USE_HASH_TABLE_KEY_CACHE +#ifdef USE_HASH_TABLE_KEY_CACHE +# define HASH_TABLE_KEY_UNSET ((uint64_t)-1) +# define HASH_TABLE_KEY_FALLBACK ((uint64_t)-2) +#endif + +/* How much smaller the table is then the total number of steps. + */ +#define BCHUNK_HASH_TABLE_DIV 16 + +/* Merge too small/large chunks: + * + * Using this means chunks below a threshold will be merged together. + * Even though short term this uses more memory, + * long term the overhead of maintaining many small chunks is reduced. + * This is defined by setting the minimum chunk size (as a fraction of the regular chunk size). + * + * Chunks may also become too large (when incrementally growing an array), + * this also enables chunk splitting. + */ +#define USE_MERGE_CHUNKS + +#ifdef USE_MERGE_CHUNKS +/* Merge chunks smaller then: (chunk_size / BCHUNK_MIN_SIZE_DIV) + */ +# define BCHUNK_SIZE_MIN_DIV 8 + +/* Disallow chunks bigger then the regular chunk size scaled by this value + * note: must be at least 2! + * however, this code runs wont run in tests unless its ~1.1 ugh. + * so lower only to check splitting works. + */ +# define BCHUNK_SIZE_MAX_MUL 2 +#endif /* USE_MERGE_CHUNKS */ + +/* slow (keep disabled), but handy for debugging */ +// #define USE_VALIDATE_LIST_SIZE + +// #define USE_VALIDATE_LIST_DATA_PARTIAL + +// #define USE_PARANOID_CHECKS + +/** \} */ + + +/** \name Internal Structs + * \{ */ + +typedef unsigned int uint; +typedef unsigned char ubyte; + +typedef uint64_t hash_key; + + +typedef struct BArrayInfo { + size_t chunk_stride; + uint chunk_count; + + /* pre-calculated */ + size_t chunk_byte_size; + size_t chunk_byte_size_min; + + size_t accum_read_ahead_bytes; +#ifdef USE_HASH_TABLE_ACCUMULATE + size_t accum_steps; + size_t accum_read_ahead_len; +#endif +} BArrayInfo; + +typedef struct BArrayMemory { + BLI_mempool *chunk_list; /* BChunkList */ + BLI_mempool *chunk_ref; /* BChunkRef */ + BLI_mempool *chunk; /* BChunk */ +} BArrayMemory; + +/** + * Main storage for all states + */ +typedef struct BArrayStore { + /* static */ + BArrayInfo info; + + /* memory storage */ + BArrayMemory memory; + + /** + * #BArrayState may be in any order (logic should never depend on state order). + */ + ListBase states; +} BArrayStore; + +/** + * A single instance of an array. + * + * This is how external API's hold a reference to an in-memory state, + * although the struct is private. + * + * \note Currently each 'state' is allocated separately. + * While this could be moved to a memory pool, + * it makes it easier to trace invalid usage, so leave as-is for now. + */ +typedef struct BArrayState { + /** linked list in #BArrayStore.states */ + struct BArrayState *next, *prev; + + struct BChunkList *chunk_list; /* BChunkList's */ + +} BArrayState; + +typedef struct BChunkList { + ListBase chunk_refs; /* BChunkRef's */ + uint chunk_refs_len; /* BLI_listbase_count(chunks), store for reuse. */ + size_t total_size; /* size of all chunks */ + + /** number of #BArrayState using this. */ + int users; +} BChunkList; + +/* a chunk of an array */ +typedef struct BChunk { + const ubyte *data; + size_t data_len; + /** number of #BChunkList using this. */ + int users; + +#ifdef USE_HASH_TABLE_KEY_CACHE + hash_key key; +#endif +} BChunk; + +/** + * Links to store #BChunk data in #BChunkList.chunks. + */ +typedef struct BChunkRef { + struct BChunkRef *next, *prev; + BChunk *link; +} BChunkRef; + +/** + * Single linked list used when putting chunks into a temporary table, + * used for lookups. + * + * Point to the #BChunkRef, not the #BChunk, + * to allow talking down the chunks in-order until a mis-match is found, + * this avoids having to do so many table lookups. + */ +typedef struct BTableRef { + struct BTableRef *next; + const BChunkRef *cref; +} BTableRef; + +/** \} */ + + +static size_t bchunk_list_size(const BChunkList *chunk_list); + + +/** \name Internal BChunk API + * \{ */ + +static BChunk *bchunk_new( + BArrayMemory *bs_mem, const ubyte *data, const size_t data_len) +{ + BChunk *chunk = BLI_mempool_alloc(bs_mem->chunk); + chunk->data = data; + chunk->data_len = data_len; + chunk->users = 0; +#ifdef USE_HASH_TABLE_KEY_CACHE + chunk->key = HASH_TABLE_KEY_UNSET; +#endif + return chunk; +} + +static BChunk *bchunk_new_copydata( + BArrayMemory *bs_mem, const ubyte *data, const size_t data_len) +{ + ubyte *data_copy = MEM_mallocN(data_len, __func__); + memcpy(data_copy, data, data_len); + return bchunk_new(bs_mem, data_copy, data_len); +} + +static void bchunk_decref( + BArrayMemory *bs_mem, BChunk *chunk) +{ + BLI_assert(chunk->users > 0); + if (chunk->users == 1) { + MEM_freeN((void *)chunk->data); + BLI_mempool_free(bs_mem->chunk, chunk); + } + else { + chunk->users -= 1; + } +} + +static bool bchunk_data_compare( + const BChunk *chunk, + const ubyte *data_base, const size_t data_base_len, + const size_t offset) +{ + if (offset + (size_t)chunk->data_len <= data_base_len) { + return (memcmp(&data_base[offset], chunk->data, chunk->data_len) == 0); + } + else { + return false; + } +} + +/** \} */ + + +/** \name Internal BChunkList API + * \{ */ + +static BChunkList *bchunk_list_new( + BArrayMemory *bs_mem, size_t total_size) +{ + BChunkList *chunk_list = BLI_mempool_alloc(bs_mem->chunk_list); + + BLI_listbase_clear(&chunk_list->chunk_refs); + chunk_list->chunk_refs_len = 0; + chunk_list->total_size = total_size; + chunk_list->users = 0; + return chunk_list; +} + +static void bchunk_list_decref( + BArrayMemory *bs_mem, BChunkList *chunk_list) +{ + BLI_assert(chunk_list->users > 0); + if (chunk_list->users == 1) { + for (BChunkRef *cref = chunk_list->chunk_refs.first, *cref_next; cref; cref = cref_next) { + cref_next = cref->next; + bchunk_decref(bs_mem, cref->link); + BLI_mempool_free(bs_mem->chunk_ref, cref); + } + + BLI_mempool_free(bs_mem->chunk_list, chunk_list); + } + else { + chunk_list->users -= 1; + } +} + +#ifdef USE_VALIDATE_LIST_SIZE +# ifndef NDEBUG +# define ASSERT_CHUNKLIST_SIZE(chunk_list, n) BLI_assert(bchunk_list_size(chunk_list) == n) +# endif +#endif +#ifndef ASSERT_CHUNKLIST_SIZE +# define ASSERT_CHUNKLIST_SIZE(chunk_list, n) (EXPR_NOP(chunk_list), EXPR_NOP(n)) +#endif + + +#ifdef USE_VALIDATE_LIST_DATA_PARTIAL +static size_t bchunk_list_data_check( + const BChunkList *chunk_list, const ubyte *data) +{ + size_t total_size = 0; + for (BChunkRef *cref = chunk_list->chunk_refs.first; cref; cref = cref->next) { + if (memcmp(&data[total_size], cref->link->data, cref->link->data_len) != 0) { + return false; + } + total_size += cref->link->data_len; + } + return true; +} +# define ASSERT_CHUNKLIST_DATA(chunk_list, data) BLI_assert(bchunk_list_data_check(chunk_list, data)) +#else +# define ASSERT_CHUNKLIST_DATA(chunk_list, data) (EXPR_NOP(chunk_list), EXPR_NOP(data)) +#endif + + +#ifdef USE_MERGE_CHUNKS +static void bchunk_list_ensure_min_size_last( + const BArrayInfo *info, BArrayMemory *bs_mem, + BChunkList *chunk_list) +{ + BChunkRef *cref = chunk_list->chunk_refs.last; + if (cref && cref->prev) { + /* both are decref'd after use (end of this block) */ + BChunk *chunk_curr = cref->link; + BChunk *chunk_prev = cref->prev->link; + + if (MIN2(chunk_prev->data_len, chunk_curr->data_len) < info->chunk_byte_size_min) { + const size_t data_merge_len = chunk_prev->data_len + chunk_curr->data_len; + /* we could pass, but no need */ + if (data_merge_len <= (info->chunk_byte_size * BCHUNK_SIZE_MAX_MUL)) { + /* we have enough space to merge */ + + /* remove last from linklist */ + BLI_assert(chunk_list->chunk_refs.last != chunk_list->chunk_refs.first); + cref->prev->next = NULL; + chunk_list->chunk_refs.last = cref->prev; + chunk_list->chunk_refs_len -= 1; + + ubyte *data_merge = MEM_mallocN(data_merge_len, __func__); + memcpy(data_merge, chunk_prev->data, chunk_prev->data_len); + memcpy(&data_merge[chunk_prev->data_len], chunk_curr->data, chunk_curr->data_len); + + cref->prev->link = bchunk_new(bs_mem, data_merge, data_merge_len); + cref->prev->link->users += 1; + + BLI_mempool_free(bs_mem->chunk_ref, cref); + } + else { + /* If we always merge small slices, we should _almost_ never end up having very large chunks. + * Gradual expanding on contracting will cause this. + * + * if we do, the code below works (test by setting 'BCHUNK_SIZE_MAX_MUL = 1.2') */ + + /* keep chunk on the left hand side a regular size */ + const size_t split = info->chunk_byte_size; + + /* merge and split */ + const size_t data_prev_len = split; + const size_t data_curr_len = data_merge_len - split; + ubyte *data_prev = MEM_mallocN(data_prev_len, __func__); + ubyte *data_curr = MEM_mallocN(data_curr_len, __func__); + + if (data_prev_len <= chunk_prev->data_len) { + const size_t data_curr_shrink_len = chunk_prev->data_len - data_prev_len; + + /* setup 'data_prev' */ + memcpy(data_prev, chunk_prev->data, data_prev_len); + + /* setup 'data_curr' */ + memcpy(data_curr, &chunk_prev->data[data_prev_len], data_curr_shrink_len); + memcpy(&data_curr[data_curr_shrink_len], chunk_curr->data, chunk_curr->data_len); + } + else { + BLI_assert(data_curr_len <= chunk_curr->data_len); + BLI_assert(data_prev_len >= chunk_prev->data_len); + + const size_t data_prev_grow_len = data_prev_len - chunk_prev->data_len; + + /* setup 'data_prev' */ + memcpy(data_prev, chunk_prev->data, chunk_prev->data_len); + memcpy(&data_prev[chunk_prev->data_len], chunk_curr->data, data_prev_grow_len); + + /* setup 'data_curr' */ + memcpy(data_curr, &chunk_curr->data[data_prev_grow_len], data_curr_len); + } + + cref->prev->link = bchunk_new(bs_mem, data_prev, data_prev_len); + cref->prev->link->users += 1; + + cref->link = bchunk_new(bs_mem, data_curr, data_curr_len); + cref->link->users += 1; + } + + /* free zero users */ + bchunk_decref(bs_mem, chunk_curr); + bchunk_decref(bs_mem, chunk_prev); + } + } +} +#endif /* USE_MERGE_CHUNKS */ + +/** + * Append and don't manage merging small chunks. + */ +static bool bchunk_list_append_only( + BArrayMemory *bs_mem, + BChunkList *chunk_list, BChunk *chunk) +{ + BChunkRef *cref = BLI_mempool_alloc(bs_mem->chunk_ref); + BLI_addtail(&chunk_list->chunk_refs, cref); + cref->link = chunk; + chunk_list->chunk_refs_len += 1; + chunk->users += 1; + return chunk; +} + +static void bchunk_list_append_data( + const BArrayInfo *info, BArrayMemory *bs_mem, + BChunkList *chunk_list, + const ubyte *data, const size_t data_len) +{ + BLI_assert(data_len != 0); + // printf("data_len: %d\n", data_len); +#ifdef USE_MERGE_CHUNKS + if (!BLI_listbase_is_empty(&chunk_list->chunk_refs)) { + BChunkRef *cref = chunk_list->chunk_refs.last; + BChunk *chunk_prev = cref->link; + + if (MIN2(chunk_prev->data_len, data_len) < info->chunk_byte_size_min) { + const size_t data_merge_len = chunk_prev->data_len + data_len; + /* realloc for single user */ + if (cref->link->users == 1) { + ubyte *data_merge = MEM_reallocN((void *)cref->link->data, data_merge_len); + memcpy(&data_merge[chunk_prev->data_len], data, data_len); + cref->link->data = data_merge; + cref->link->data_len = data_merge_len; + } + else { + ubyte *data_merge = MEM_mallocN(data_merge_len, __func__); + memcpy(data_merge, chunk_prev->data, chunk_prev->data_len); + memcpy(&data_merge[chunk_prev->data_len], data, data_len); + cref->link = bchunk_new(bs_mem, data_merge, data_merge_len); + cref->link->users += 1; + bchunk_decref(bs_mem, chunk_prev); + } + return; + } + } +#else + UNUSED_VARS(info); +#endif /* USE_MERGE_CHUNKS */ + + BChunk *chunk = bchunk_new_copydata(bs_mem, data, data_len); + bchunk_list_append_only(bs_mem, chunk_list, chunk); + + /* don't run this, instead preemptively avoid creating a chunk only to merge it (above). */ +#if 0 +#ifdef USE_MERGE_CHUNKS + bchunk_list_ensure_min_size_last(info, bs_mem, chunk_list, chunk_size_min); +#endif +#endif +} + +static void bchunk_list_append( + const BArrayInfo *info, BArrayMemory *bs_mem, + BChunkList *chunk_list, + BChunk *chunk) +{ + bchunk_list_append_only(bs_mem, chunk_list, chunk); + +#ifdef USE_MERGE_CHUNKS + bchunk_list_ensure_min_size_last(info, bs_mem, chunk_list); +#else + UNUSED_VARS(info); +#endif +} + +static void bchunk_list_fill_from_array( + const BArrayInfo *info, BArrayMemory *bs_mem, + BChunkList *chunk_list, + const ubyte *data, + const size_t data_len) +{ + BLI_assert(BLI_listbase_is_empty(&chunk_list->chunk_refs)); + + size_t data_last_chunk_len = 0; + size_t data_trim_len = data_len; + +#ifdef USE_MERGE_CHUNKS + /* avoid creating too-small chunks + * more efficient then merging after */ + if (data_len > info->chunk_byte_size) { + data_last_chunk_len = (data_trim_len % info->chunk_byte_size); + data_trim_len = data_trim_len - data_last_chunk_len; + if (data_last_chunk_len) { + if (data_last_chunk_len < info->chunk_byte_size_min) { + /* may be zero and thats OK */ + data_trim_len -= info->chunk_byte_size; + data_last_chunk_len += info->chunk_byte_size; + } + } + } + else { + data_trim_len = 0; + data_last_chunk_len = data_len; + } +#else + data_last_chunk_len = (data_trim_len % info->chunk_byte_size); + data_trim_len = data_trim_len - data_last_chunk_len; +#endif + + + BLI_assert(data_trim_len + data_last_chunk_len == data_len); + + size_t i_prev = 0; + while (i_prev < data_trim_len) { + const size_t i = i_prev + info->chunk_byte_size; + BChunk *chunk = bchunk_new_copydata(bs_mem, &data[i_prev], i - i_prev); + bchunk_list_append_only(bs_mem, chunk_list, chunk); + i_prev = i; + } + + if (data_last_chunk_len) { + BChunk *chunk = bchunk_new_copydata(bs_mem, &data[i_prev], data_last_chunk_len); + bchunk_list_append_only(bs_mem, chunk_list, chunk); + // i_prev = data_len; + } + +#ifdef USE_MERGE_CHUNKS + if (data_len > info->chunk_byte_size) { + BLI_assert(((BChunkRef *)chunk_list->chunk_refs.last)->link->data_len >= info->chunk_byte_size_min); + } +#endif + + /* works but better avoid redundant re-alloc */ +#if 0 +#ifdef USE_MERGE_CHUNKS + bchunk_list_ensure_min_size_last(info, bs_mem, chunk_list); +#endif +#endif + + ASSERT_CHUNKLIST_SIZE(chunk_list, data_len); + ASSERT_CHUNKLIST_DATA(chunk_list, data); +} + + +/* --------------------------------------------------------------------------- + * Internal Table Lookup Functions + */ + +/** \name Internal Hashing/De-Duplication API + * + * Only used by #bchunk_list_from_data_merge + * \{ */ + +#define HASH_INIT (5381) + +BLI_INLINE uint hash_data_single(const ubyte p) +{ + return (HASH_INIT << 5) + HASH_INIT + (unsigned int)p; +} + +/* hash bytes, from BLI_ghashutil_strhash_n */ +static uint hash_data(const ubyte *key, size_t n) +{ + const signed char *p; + unsigned int h = HASH_INIT; + + for (p = (const signed char *)key; n--; p++) { + h = (h << 5) + h + (unsigned int)*p; + } + + return h; +} + +#undef HASH_INIT + + +#ifdef USE_HASH_TABLE_ACCUMULATE +static void hash_array_from_data( + const BArrayInfo *info, const ubyte *data_slice, const size_t data_slice_len, + hash_key *hash_array) +{ + if (info->chunk_stride != 1) { + for (size_t i = 0, i_step = 0; i_step < data_slice_len; i++, i_step += info->chunk_stride) { + hash_array[i] = hash_data(&data_slice[i_step], info->chunk_stride); + } + } + else { + /* fast-path for bytes */ + for (size_t i = 0; i < data_slice_len; i++) { + hash_array[i] = hash_data_single(data_slice[i]); + } + } +} + +/* + * Similar to hash_array_from_data, + * but able to step into the next chunk if we run-out of data. + */ +static void hash_array_from_cref( + const BArrayInfo *info, const BChunkRef *cref, const size_t data_len, + hash_key *hash_array) +{ + const size_t hash_array_len = data_len / info->chunk_stride; + size_t i = 0; + do { + size_t i_next = hash_array_len - i; + size_t data_trim_len = i_next * info->chunk_stride; + if (data_trim_len > cref->link->data_len) { + data_trim_len = cref->link->data_len; + i_next = data_trim_len / info->chunk_stride; + } + BLI_assert(data_trim_len <= cref->link->data_len); + hash_array_from_data(info, cref->link->data, data_trim_len, &hash_array[i]); + i += i_next; + cref = cref->next; + } while ((i < hash_array_len) && (cref != NULL)); + + /* If this isn't equal, the caller didn't properly check + * that there was enough data left in all chunks */ + BLI_assert(i == hash_array_len); +} + +static void hash_accum(hash_key *hash_array, const size_t hash_array_len, size_t iter_steps) +{ + /* _very_ unlikely, can happen if you select a chunk-size of 1 for example. */ + if (UNLIKELY((iter_steps > hash_array_len))) { + iter_steps = hash_array_len; + } + + const size_t hash_array_search_len = hash_array_len - iter_steps; + while (iter_steps != 0) { + const size_t hash_offset = iter_steps; + for (uint i = 0; i < hash_array_search_len; i++) { + hash_array[i] += (hash_array[i + hash_offset]) * ((hash_array[i] & 0xff) + 1); + } + iter_steps -= 1; + } +} + +/** + * When we only need a single value, can use a small optimization. + * we can avoid accumulating the tail of the array a little, each iteration. + */ +static void hash_accum_single(hash_key *hash_array, const size_t hash_array_len, size_t iter_steps) +{ + BLI_assert(iter_steps <= hash_array_len); + if (UNLIKELY(!(iter_steps <= hash_array_len))) { + /* while this shouldn't happen, avoid crashing */ + iter_steps = hash_array_len; + } + /* We can increase this value each step to avoid accumulating quite as much + * while getting the same results as hash_accum */ + size_t iter_steps_sub = iter_steps; + + while (iter_steps != 0) { + const size_t hash_array_search_len = hash_array_len - iter_steps_sub; + const size_t hash_offset = iter_steps; + for (uint i = 0; i < hash_array_search_len; i++) { + hash_array[i] += (hash_array[i + hash_offset]) * ((hash_array[i] & 0xff) + 1); + } + iter_steps -= 1; + iter_steps_sub += iter_steps; + } +} + +static hash_key key_from_chunk_ref( + const BArrayInfo *info, const BChunkRef *cref, + /* avoid reallicating each time */ + hash_key *hash_store, const size_t hash_store_len) +{ + /* in C, will fill in a reusable array */ + BChunk *chunk = cref->link; + BLI_assert(info->accum_read_ahead_bytes * info->chunk_stride); + + if (info->accum_read_ahead_bytes <= chunk->data_len) { + hash_key key; + +#ifdef USE_HASH_TABLE_KEY_CACHE + key = chunk->key; + if (key != HASH_TABLE_KEY_UNSET) { + /* Using key cache! + * avoids calculating every time */ + } + else { + hash_array_from_cref(info, cref, info->accum_read_ahead_bytes, hash_store); + hash_accum_single(hash_store, hash_store_len, info->accum_steps); + key = hash_store[0]; + + /* cache the key */ + if (key == HASH_TABLE_KEY_UNSET) { + key = HASH_TABLE_KEY_FALLBACK; + } + chunk->key = key; + } +#else + hash_array_from_cref(info, cref, info->accum_read_ahead_bytes, hash_store); + hash_accum_single(hash_store, hash_store_len, info->accum_steps); + key = hash_store[0]; +#endif + return key; + } + else { + /* corner case - we're too small, calculate the key each time. */ + + hash_array_from_cref(info, cref, info->accum_read_ahead_bytes, hash_store); + hash_accum_single(hash_store, hash_store_len, info->accum_steps); + hash_key key = hash_store[0]; + +#ifdef USE_HASH_TABLE_KEY_CACHE + if (UNLIKELY(key == HASH_TABLE_KEY_UNSET)) { + key = HASH_TABLE_KEY_FALLBACK; + } +#endif + return key; + } +} + +static const BChunkRef *table_lookup( + const BArrayInfo *info, BTableRef **table, const size_t table_len, const size_t i_table_start, + const ubyte *data, const size_t data_len, const size_t offset, const hash_key *table_hash_array) +{ + size_t size_left = data_len - offset; + hash_key key = table_hash_array[((offset - i_table_start) / info->chunk_stride)]; + size_t key_index = (size_t)(key % (hash_key)table_len); + for (BTableRef *tref = table[key_index]; tref; tref = tref->next) { + const BChunkRef *cref = tref->cref; +#ifdef USE_HASH_TABLE_KEY_CACHE + if (cref->link->key == key) +#endif + { + BChunk *chunk_test = cref->link; + if (chunk_test->data_len <= size_left) { + if (bchunk_data_compare(chunk_test, data, data_len, offset)) { + /* we could remove the chunk from the table, to avoid multiple hits */ + return cref; + } + } + } + } + return NULL; +} + +#else /* USE_HASH_TABLE_ACCUMULATE */ + +/* NON USE_HASH_TABLE_ACCUMULATE code (simply hash each chunk) */ + +static hash_key key_from_chunk_ref(const BArrayInfo *info, const BChunkRef *cref) +{ + const size_t data_hash_len = BCHUNK_HASH_LEN * info->chunk_stride; + hash_key key; + BChunk *chunk = cref->link; + +#ifdef USE_HASH_TABLE_KEY_CACHE + key = chunk->key; + if (key != HASH_TABLE_KEY_UNSET) { + /* Using key cache! + * avoids calculating every time */ + } + else { + /* cache the key */ + key = hash_data(chunk->data, data_hash_len); + if (key == HASH_TABLE_KEY_UNSET) { + key = HASH_TABLE_KEY_FALLBACK; + } + chunk->key = key; + } +#else + key = hash_data(chunk->data, data_hash_len); +#endif + + return key; +} + +static const BChunkRef *table_lookup( + const BArrayInfo *info, BTableRef **table, const size_t table_len, const uint UNUSED(i_table_start), + const ubyte *data, const size_t data_len, const size_t offset, const hash_key *UNUSED(table_hash_array)) +{ + const size_t data_hash_len = BCHUNK_HASH_LEN * info->chunk_stride; /* TODO, cache */ + + size_t size_left = data_len - offset; + hash_key key = hash_data(&data[offset], MIN2(data_hash_len, size_left)); + size_t key_index = (size_t)(key % (hash_key)table_len); + for (BTableRef *tref = table[key_index]; tref; tref = tref->next) { + const BChunkRef *cref = tref->cref; +#ifdef USE_HASH_TABLE_KEY_CACHE + if (cref->link->key == key) +#endif + { + BChunk *chunk_test = cref->link; + if (chunk_test->data_len <= size_left) { + if (bchunk_data_compare(chunk_test, data, data_len, offset)) { + /* we could remove the chunk from the table, to avoid multiple hits */ + return cref; + } + } + } + } + return NULL; +} + +#endif /* USE_HASH_TABLE_ACCUMULATE */ + +/* End Table Lookup + * ---------------- */ + +/** \} */ + +/** + * \param data: Data to store in the returned value. + * \param data_len_original: Length of data in bytes. + * \param chunk_list_reference: Reuse this list or chunks within it, don't modify its content. + * \note Caller is responsible for adding the user. + */ +static BChunkList *bchunk_list_from_data_merge( + const BArrayInfo *info, BArrayMemory *bs_mem, + const ubyte *data, const size_t data_len_original, + const BChunkList *chunk_list_reference) +{ + ASSERT_CHUNKLIST_SIZE(chunk_list_reference, chunk_list_reference->total_size); + + /* ----------------------------------------------------------------------- + * Fast-Path for exact match + * Check for exact match, if so, return the current list. + */ + + const BChunkRef *cref_match_first = NULL; + + uint chunk_list_reference_skip_len = 0; + size_t chunk_list_reference_skip_bytes = 0; + size_t i_prev = 0; + +#ifdef USE_FASTPATH_CHUNKS_FIRST + bool full_match = false; + + { + full_match = true; + + const BChunkRef *cref = chunk_list_reference->chunk_refs.first; + while (i_prev < data_len_original) { + if (cref != NULL && bchunk_data_compare(cref->link, data, data_len_original, i_prev)) { + cref_match_first = cref; + chunk_list_reference_skip_len += 1; + chunk_list_reference_skip_bytes += cref->link->data_len; + i_prev += cref->link->data_len; + cref = cref->next; + } + else { + full_match = false; + break; + } + } + + if (full_match) { + if (chunk_list_reference->total_size == data_len_original) { + return (BChunkList *)chunk_list_reference; + } + } + } + + /* End Fast-Path (first) + * --------------------- */ + +#endif /* USE_FASTPATH_CHUNKS_FIRST */ + + /* Copy until we have a mismatch */ + BChunkList *chunk_list = bchunk_list_new(bs_mem, data_len_original); + if (cref_match_first != NULL) { + size_t chunk_size_step = 0; + const BChunkRef *cref = chunk_list_reference->chunk_refs.first; + while (true) { + BChunk *chunk = cref->link; + chunk_size_step += chunk->data_len; + bchunk_list_append_only(bs_mem, chunk_list, chunk); + ASSERT_CHUNKLIST_SIZE(chunk_list, chunk_size_step); + ASSERT_CHUNKLIST_DATA(chunk_list, data); + if (cref == cref_match_first) { + break; + } + else { + cref = cref->next; + } + } + /* happens when bytes are removed from the end of the array */ + if (chunk_size_step == data_len_original) { + return chunk_list; + } + + i_prev = chunk_size_step; + } + else { + i_prev = 0; + } + + /* ------------------------------------------------------------------------ + * Fast-Path for end chunks + * + * Check for trailing chunks + */ + + /* In this case use 'chunk_list_reference_last' to define the last index + * index_match_last = -1 */ + + /* warning, from now on don't use len(data) + * since we want to ignore chunks already matched */ + size_t data_len = data_len_original; +#define data_len_original invalid_usage +#ifdef data_len_original /* quiet warning */ +#endif + + const BChunkRef *chunk_list_reference_last = NULL; + +#ifdef USE_FASTPATH_CHUNKS_LAST + if (!BLI_listbase_is_empty(&chunk_list_reference->chunk_refs)) { + const BChunkRef *cref = chunk_list_reference->chunk_refs.last; + while ((cref->prev != NULL) && + (cref != cref_match_first) && + (cref->link->data_len <= data_len - i_prev)) + { + BChunk *chunk_test = cref->link; + size_t offset = data_len - chunk_test->data_len; + if (bchunk_data_compare(chunk_test, data, data_len, offset)) { + data_len = offset; + chunk_list_reference_last = cref; + chunk_list_reference_skip_len += 1; + chunk_list_reference_skip_bytes += cref->link->data_len; + cref = cref->prev; + } + else { + break; + } + } + } + + /* End Fast-Path (last) + * -------------------- */ +#endif /* USE_FASTPATH_CHUNKS_LAST */ + + /* ----------------------------------------------------------------------- + * Check for aligned chunks + * + * This saves a lot of searching, so use simple heuristics to detect aligned arrays. + * (may need to tweak exact method). + */ + + bool use_aligned = false; + +#ifdef USE_ALIGN_CHUNKS_TEST + if (chunk_list->total_size == chunk_list_reference->total_size) { + /* if we're already a quarter aligned */ + if (data_len - i_prev <= chunk_list->total_size / 4) { + use_aligned = true; + } + else { + /* TODO, walk over chunks and check if some arbitrary amount align */ + } + } +#endif /* USE_ALIGN_CHUNKS_TEST */ + + /* End Aligned Chunk Case + * ----------------------- */ + + if (use_aligned) { + /* Copy matching chunks, creates using the same 'layout' as the reference */ + const BChunkRef *cref = cref_match_first ? cref_match_first->next : chunk_list_reference->chunk_refs.first; + while (i_prev != data_len) { + const size_t i = i_prev + cref->link->data_len; + BLI_assert(i != i_prev); + + if ((cref != chunk_list_reference_last) && + bchunk_data_compare(cref->link, data, data_len, i_prev)) + { + bchunk_list_append(info, bs_mem, chunk_list, cref->link); + ASSERT_CHUNKLIST_SIZE(chunk_list, i); + ASSERT_CHUNKLIST_DATA(chunk_list, data); + } + else { + bchunk_list_append_data(info, bs_mem, chunk_list, &data[i_prev], i - i_prev); + ASSERT_CHUNKLIST_SIZE(chunk_list, i); + ASSERT_CHUNKLIST_DATA(chunk_list, data); + } + + cref = cref->next; + + i_prev = i; + } + } + else if ((data_len - i_prev >= info->chunk_byte_size) && + (chunk_list_reference->chunk_refs_len >= chunk_list_reference_skip_len) && + (chunk_list_reference->chunk_refs.first != NULL)) + { + + /* -------------------------------------------------------------------- + * Non-Aligned Chunk De-Duplication */ + + /* only create a table if we have at least one chunk to search + * otherwise just make a new one. + * + * Support re-arranged chunks */ + +#ifdef USE_HASH_TABLE_ACCUMULATE + size_t i_table_start = i_prev; + const size_t table_hash_array_len = (data_len - i_prev) / info->chunk_stride; + hash_key *table_hash_array = MEM_mallocN(sizeof(*table_hash_array) * table_hash_array_len, __func__); + hash_array_from_data(info, &data[i_prev], data_len - i_prev, table_hash_array); + + hash_accum(table_hash_array, table_hash_array_len, info->accum_steps); +#else + /* dummy vars */ + uint i_table_start = 0; + hash_key *table_hash_array = NULL; +#endif + + const size_t table_len = MAX2(1u, (((data_len - i_prev) / info->chunk_stride)) / BCHUNK_HASH_TABLE_DIV); + BTableRef **table = MEM_callocN(table_len * sizeof(*table), __func__); + + const uint chunk_list_reference_remaining_len = + (chunk_list_reference->chunk_refs_len - chunk_list_reference_skip_len) + 1; + BTableRef *table_ref_stack = MEM_mallocN(chunk_list_reference_remaining_len * sizeof(BTableRef), __func__); + uint table_ref_stack_n = 0; + + /* table_make - inline + * include one matching chunk, to allow for repeating values */ + { +#ifdef USE_HASH_TABLE_ACCUMULATE + const size_t hash_store_len = info->accum_read_ahead_len; + hash_key *hash_store = MEM_mallocN(sizeof(hash_key) * hash_store_len, __func__); +#endif + + const BChunkRef *cref; + size_t chunk_list_reference_bytes_remaining = + chunk_list_reference->total_size - chunk_list_reference_skip_bytes; + + if (cref_match_first) { + cref = cref_match_first; + chunk_list_reference_bytes_remaining += cref->link->data_len; + } + else { + cref = chunk_list_reference->chunk_refs.first; + } + +#ifdef USE_PARANOID_CHECKS + { + size_t test_bytes_len = 0; + const BChunkRef *cr = cref; + while (cr != chunk_list_reference_last) { + test_bytes_len += cr->link->data_len; + cr = cr->next; + } + BLI_assert(test_bytes_len == chunk_list_reference_bytes_remaining); + } +#endif + + while ((cref != chunk_list_reference_last) && + (chunk_list_reference_bytes_remaining >= info->accum_read_ahead_bytes)) + { + hash_key key = key_from_chunk_ref(info, cref + +#ifdef USE_HASH_TABLE_ACCUMULATE + , hash_store, hash_store_len +#endif + ); + size_t key_index = (size_t)(key % (hash_key)table_len); + BTableRef *tref_prev = table[key_index]; + BLI_assert(table_ref_stack_n < chunk_list_reference_remaining_len); + BTableRef *tref = &table_ref_stack[table_ref_stack_n++]; + tref->cref = cref; + tref->next = tref_prev; + table[key_index] = tref; + + chunk_list_reference_bytes_remaining -= cref->link->data_len; + cref = cref->next; + } + + BLI_assert(table_ref_stack_n <= chunk_list_reference_remaining_len); + +#ifdef USE_HASH_TABLE_ACCUMULATE + MEM_freeN(hash_store); +#endif + } + /* done making the table */ + + BLI_assert(i_prev <= data_len); + for (size_t i = i_prev; i < data_len; ) { + /* Assumes exiting chunk isnt a match! */ + + const BChunkRef *cref_found = table_lookup( + info, + table, table_len, i_table_start, + data, data_len, i, table_hash_array); + if (cref_found != NULL) { + BLI_assert(i < data_len); + if (i != i_prev) { + size_t i_step = MIN2(i_prev + info->chunk_byte_size, data_len); + BLI_assert(i_step <= data_len); + + while (i_prev != i) { + i_step = MIN2(i_step, i); + const ubyte *data_slice = &data[i_prev]; + const size_t data_slice_len = i_step - i_prev; + /* First add all previous chunks! */ + i_prev += data_slice_len; + bchunk_list_append_data(info, bs_mem, chunk_list, data_slice, data_slice_len); + BLI_assert(i_prev <= data_len); + ASSERT_CHUNKLIST_SIZE(chunk_list, i_prev); + ASSERT_CHUNKLIST_DATA(chunk_list, data); + i_step += info->chunk_byte_size; + } + } + + /* now add the reference chunk */ + { + BChunk *chunk_found = cref_found->link; + i += chunk_found->data_len; + bchunk_list_append(info, bs_mem, chunk_list, chunk_found); + } + i_prev = i; + BLI_assert(i_prev <= data_len); + ASSERT_CHUNKLIST_SIZE(chunk_list, i_prev); + ASSERT_CHUNKLIST_DATA(chunk_list, data); + + /* its likely that the next chunk in the list will be a match, so check it! */ + while ((cref_found->next != NULL) && + (cref_found->next != chunk_list_reference_last)) + { + cref_found = cref_found->next; + BChunk *chunk_found = cref_found->link; + + if (bchunk_data_compare(chunk_found, data, data_len, i_prev)) { + /* may be useful to remove table data, assuming we dont have repeating memory + * where it would be useful to re-use chunks. */ + i += chunk_found->data_len; + bchunk_list_append(info, bs_mem, chunk_list, chunk_found); + /* chunk_found may be freed! */ + i_prev = i; + BLI_assert(i_prev <= data_len); + ASSERT_CHUNKLIST_SIZE(chunk_list, i_prev); + ASSERT_CHUNKLIST_DATA(chunk_list, data); + } + else { + break; + } + } + } + else { + i = i + info->chunk_stride; + } + } + +#ifdef USE_HASH_TABLE_ACCUMULATE + MEM_freeN(table_hash_array); +#endif + MEM_freeN(table); + MEM_freeN(table_ref_stack); + + /* End Table Lookup + * ---------------- */ + } + + ASSERT_CHUNKLIST_SIZE(chunk_list, i_prev); + ASSERT_CHUNKLIST_DATA(chunk_list, data); + + /* ----------------------------------------------------------------------- + * No Duplicates to copy, write new chunks + * + * Trailing chunks, no matches found in table lookup above. + * Write all new data. */ + BLI_assert(i_prev <= data_len); + while (i_prev != data_len) { + size_t i = i_prev + info->chunk_byte_size; + i = MIN2(i, data_len); + BLI_assert(i != i_prev); + bchunk_list_append_data(info, bs_mem, chunk_list, &data[i_prev], i - i_prev); + ASSERT_CHUNKLIST_DATA(chunk_list, data); + i_prev = i; + } + + BLI_assert(i_prev == data_len); + +#ifdef USE_FASTPATH_CHUNKS_LAST + if (chunk_list_reference_last != NULL) { + /* write chunk_list_reference_last since it hasn't been written yet */ + const BChunkRef *cref = chunk_list_reference_last; + while (cref != NULL) { + BChunk *chunk = cref->link; + // BLI_assert(bchunk_data_compare(chunk, data, data_len, i_prev)); + i_prev += chunk->data_len; + /* use simple since we assume the references chunks have already been sized correctly. */ + bchunk_list_append_only(bs_mem, chunk_list, chunk); + ASSERT_CHUNKLIST_DATA(chunk_list, data); + cref = cref->next; + } + } +#endif + +#undef data_len_original + + BLI_assert(i_prev == data_len_original); + + /* check we're the correct size and that we didn't accidentally modify the reference */ + ASSERT_CHUNKLIST_SIZE(chunk_list, data_len_original); + ASSERT_CHUNKLIST_SIZE(chunk_list_reference, chunk_list_reference->total_size); + + ASSERT_CHUNKLIST_DATA(chunk_list, data); + + return chunk_list; +} +/* end private API */ + +/** \} */ + + +/** \name Main Array Storage API + * \{ */ + + +/** + * Create a new array store, which can store any number of arrays + * as long as their stride matches. + * + * \param stride: ``sizeof()`` each element, + * + * \note while a stride of ``1`` will always work, + * its less efficient since duplicate chunks of memory will be searched + * at positions unaligned with the array data. + * + * \param chunk_count: Number of elements to split each chunk into. + * - A small value increases the ability to de-duplicate chunks, + * but adds overhead by increasing the number of chunks to look-up when searching for duplicates, + * as well as some overhead constructing the original array again, with more calls to ``memcpy``. + * - Larger values reduce the *book keeping* overhead, + * but increase the chance a small, isolated change will cause a larger amount of data to be duplicated. + * + * \return A new array store, to be freed with #BLI_array_store_destroy. + */ +BArrayStore *BLI_array_store_create( + uint stride, + uint chunk_count) +{ + BArrayStore *bs = MEM_callocN(sizeof(BArrayStore), __func__); + + bs->info.chunk_stride = stride; + bs->info.chunk_count = chunk_count; + + bs->info.chunk_byte_size = chunk_count * stride; +#ifdef USE_MERGE_CHUNKS + bs->info.chunk_byte_size_min = MAX2(1u, chunk_count / BCHUNK_SIZE_MIN_DIV) * stride; +#endif + +#ifdef USE_HASH_TABLE_ACCUMULATE + bs->info.accum_steps = BCHUNK_HASH_TABLE_ACCUMULATE_STEPS - 1; + /* Triangle number, identifying now much read-ahead we need: + * https://en.wikipedia.org/wiki/Triangular_number (+ 1) */ + bs->info.accum_read_ahead_len = (uint)((((bs->info.accum_steps * (bs->info.accum_steps + 1))) / 2) + 1); + bs->info.accum_read_ahead_bytes = bs->info.accum_read_ahead_len * stride; +#else + bs->info.accum_read_ahead_bytes = BCHUNK_HASH_LEN * stride; +#endif + + bs->memory.chunk_list = BLI_mempool_create(sizeof(BChunkList), 0, 512, BLI_MEMPOOL_NOP); + bs->memory.chunk_ref = BLI_mempool_create(sizeof(BChunkRef), 0, 512, BLI_MEMPOOL_NOP); + /* allow iteration to simplify freeing, otherwise its not needed + * (we could loop over all states as an alternative). */ + bs->memory.chunk = BLI_mempool_create(sizeof(BChunk), 0, 512, BLI_MEMPOOL_ALLOW_ITER); + + return bs; +} + +static void array_store_free_data(BArrayStore *bs) +{ + /* free chunk data */ + { + BLI_mempool_iter iter; + BChunk *chunk; + BLI_mempool_iternew(bs->memory.chunk, &iter); + while ((chunk = BLI_mempool_iterstep(&iter))) { + BLI_assert(chunk->users > 0); + MEM_freeN((void *)chunk->data); + } + } + + /* free states */ + for (BArrayState *state = bs->states.first, *state_next; state; state = state_next) { + state_next = state->next; + MEM_freeN(state); + } +} + +/** + * Free the #BArrayStore, including all states and chunks. + */ +void BLI_array_store_destroy( + BArrayStore *bs) +{ + array_store_free_data(bs); + + BLI_mempool_destroy(bs->memory.chunk_list); + BLI_mempool_destroy(bs->memory.chunk_ref); + BLI_mempool_destroy(bs->memory.chunk); + + MEM_freeN(bs); +} + +/** + * Clear all contents, allowing reuse of \a bs. + */ +void BLI_array_store_clear( + BArrayStore *bs) +{ + array_store_free_data(bs); + + BLI_listbase_clear(&bs->states); + + BLI_mempool_clear(bs->memory.chunk_list); + BLI_mempool_clear(bs->memory.chunk_ref); + BLI_mempool_clear(bs->memory.chunk); +} + +/** \name BArrayStore Statistics + * \{ */ + +/** + * \return the total amount of memory that would be used by getting the arrays for all states. + */ +size_t BLI_array_store_calc_size_expanded_get( + const BArrayStore *bs) +{ + size_t size_accum = 0; + for (const BArrayState *state = bs->states.first; state; state = state->next) { + size_accum += state->chunk_list->total_size; + } + return size_accum; +} + +/** + * \return the amount of memory used by all #BChunk.data + * (duplicate chunks are only counted once). + */ +size_t BLI_array_store_calc_size_compacted_get( + const BArrayStore *bs) +{ + size_t size_total = 0; + BLI_mempool_iter iter; + BChunk *chunk; + BLI_mempool_iternew(bs->memory.chunk, &iter); + while ((chunk = BLI_mempool_iterstep(&iter))) { + BLI_assert(chunk->users > 0); + size_total += (size_t)chunk->data_len; + } + return size_total; +} + +/** \} */ + + +/** \name BArrayState Access + * \{ */ + +/** + * + * \param data: Data used to create + * \param state_reference: The state to use as a reference when adding the new state, + * typically this is the previous state, + * however it can be any previously created state from this \a bs. + * + * \return The new state, which is used by the caller as a handle to get back the contents of \a data. + * This may be removed using #BLI_array_store_state_remove, + * otherwise it will be removed with #BLI_array_store_destroy. + */ +BArrayState *BLI_array_store_state_add( + BArrayStore *bs, + const void *data, const size_t data_len, + const BArrayState *state_reference) +{ + /* ensure we're aligned to the stride */ + BLI_assert((data_len % bs->info.chunk_stride) == 0); + +#ifdef USE_PARANOID_CHECKS + if (state_reference) { + BLI_assert(BLI_findindex(&bs->states, state_reference) != -1); + } +#endif + + static BChunkList *chunk_list; + if (state_reference) { + chunk_list = bchunk_list_from_data_merge( + &bs->info, &bs->memory, + (const ubyte *)data, data_len, + /* re-use reference chunks */ + state_reference->chunk_list); + } + else { + chunk_list = bchunk_list_new(&bs->memory, data_len); + bchunk_list_fill_from_array( + &bs->info, &bs->memory, + chunk_list, + (const ubyte *)data, data_len); + } + + chunk_list->users += 1; + + BArrayState *state = MEM_callocN(sizeof(BArrayState), __func__); + state->chunk_list = chunk_list; + + BLI_addtail(&bs->states, state); + +#ifdef USE_PARANOID_CHECKS + { + size_t data_test_len; + void *data_test = BLI_array_store_state_data_get_alloc(state, &data_test_len); + BLI_assert(data_test_len == data_len); + BLI_assert(memcmp(data_test, data, data_len) == 0); + MEM_freeN(data_test); + } +#endif + + return state; +} + +/** + * Remove a state and free any unused #BChunk data. + * + * The states can be freed in any order. + */ +void BLI_array_store_state_remove( + BArrayStore *bs, + BArrayState *state) +{ +#ifdef USE_PARANOID_CHECKS + BLI_assert(BLI_findindex(&bs->states, state) != -1); +#endif + + bchunk_list_decref(&bs->memory, state->chunk_list); + BLI_remlink(&bs->states, state); + + MEM_freeN(state); +} + +/** + * \return the expanded size of the array, + * use this to know how much memory to allocate #BLI_array_store_state_data_get's argument. + */ +size_t BLI_array_store_state_size_get( + BArrayState *state) +{ + return state->chunk_list->total_size; +} + +/** + * Fill in existing allocated memory with the contents of \a state. + */ +void BLI_array_store_state_data_get( + BArrayState *state, + void *data) +{ +#ifdef USE_PARANOID_CHECKS + size_t data_test_len = 0; + for (BChunkRef *cref = state->chunk_list->chunk_refs.first; cref; cref = cref->next) { + data_test_len += cref->link->data_len; + } + BLI_assert(data_test_len == state->chunk_list->total_size); +#endif + + ubyte *data_step = (ubyte *)data; + for (BChunkRef *cref = state->chunk_list->chunk_refs.first; cref; cref = cref->next) { + BLI_assert(cref->link->users > 0); + memcpy(data_step, cref->link->data, cref->link->data_len); + data_step += cref->link->data_len; + } +} + +/** + * Allocate an array for \a state and return it. + */ +void *BLI_array_store_state_data_get_alloc( + BArrayState *state, + size_t *r_data_len) +{ + void *data = MEM_mallocN(state->chunk_list->total_size, __func__); + BLI_array_store_state_data_get(state, data); + *r_data_len = state->chunk_list->total_size; + return data; +} + +/** \} */ + + +/** \name Debigging API (for testing). + * \{ */ + +/* only for test validation */ +static size_t bchunk_list_size(const BChunkList *chunk_list) +{ + size_t total_size = 0; + for (BChunkRef *cref = chunk_list->chunk_refs.first; cref; cref = cref->next) { + total_size += cref->link->data_len; + } + return total_size; +} + +bool BLI_array_store_is_valid( + BArrayStore *bs) +{ + bool ok = true; + + /* Check Length + * ------------ */ + + for (BArrayState *state = bs->states.first; state; state = state->next) { + BChunkList *chunk_list = state->chunk_list; + if (!(bchunk_list_size(chunk_list) == chunk_list->total_size)) { + return false; + } + } + + { + BLI_mempool_iter iter; + BChunk *chunk; + BLI_mempool_iternew(bs->memory.chunk, &iter); + while ((chunk = BLI_mempool_iterstep(&iter))) { + if (!(MEM_allocN_len(chunk->data) >= chunk->data_len)) { + return false; + } + } + } + + /* Check User Count & Lost References + * ---------------------------------- */ + { + GHashIterator gh_iter; + +#define GHASH_PTR_ADD_USER(gh, pt) \ + { \ + void **val; \ + if (BLI_ghash_ensure_p((gh), (pt), &val)) { \ + *((int *)val) += 1; \ + } \ + else { \ + *((int *)val) = 1; \ + } \ + } ((void)0) + + + /* count chunk_list's */ + int totrefs = 0; + GHash *chunk_list_map = BLI_ghash_ptr_new(__func__); + for (BArrayState *state = bs->states.first; state; state = state->next) { + GHASH_PTR_ADD_USER(chunk_list_map, state->chunk_list); + } + GHASH_ITER (gh_iter, chunk_list_map) { + const struct BChunkList *chunk_list = BLI_ghashIterator_getKey(&gh_iter); + const int users = GET_INT_FROM_POINTER(BLI_ghashIterator_getValue(&gh_iter)); + if (!(chunk_list->users == users)) { + ok = false; + goto user_finally; + } + } + if (!(BLI_mempool_count(bs->memory.chunk_list) == (int)BLI_ghash_size(chunk_list_map))) { + ok = false; + goto user_finally; + } + + /* count chunk's */ + GHash *chunk_map = BLI_ghash_ptr_new(__func__); + GHASH_ITER (gh_iter, chunk_list_map) { + const struct BChunkList *chunk_list = BLI_ghashIterator_getKey(&gh_iter); + for (const BChunkRef *cref = chunk_list->chunk_refs.first; cref; cref = cref->next) { + GHASH_PTR_ADD_USER(chunk_map, cref->link); + totrefs += 1; + } + } + if (!(BLI_mempool_count(bs->memory.chunk) == (int)BLI_ghash_size(chunk_map))) { + ok = false; + goto user_finally; + } + if (!(BLI_mempool_count(bs->memory.chunk_ref) == totrefs)) { + ok = false; + goto user_finally; + } + + GHASH_ITER (gh_iter, chunk_map) { + const struct BChunk *chunk = BLI_ghashIterator_getKey(&gh_iter); + const int users = GET_INT_FROM_POINTER(BLI_ghashIterator_getValue(&gh_iter)); + if (!(chunk->users == users)) { + ok = false; + goto user_finally; + } + } + +#undef GHASH_PTR_ADD_USER + +user_finally: + BLI_ghash_free(chunk_list_map, NULL, NULL); + BLI_ghash_free(chunk_map, NULL, NULL); + } + + + return ok; + /* TODO, dangling pointer checks */ +} + +/** \} */ |