Message ID | 20240224200603.6613-1-connorbworley@gmail.com |
---|---|
State | New |
Headers | show |
Series | [FFmpeg-devel,v4,1/2] lavu/hashtable: create generic robin hood hash table | expand |
Context | Check | Description |
---|---|---|
yinshiyou/make_loongarch64 | success | Make finished |
yinshiyou/make_fate_loongarch64 | success | Make fate finished |
andriy/make_x86 | success | Make finished |
andriy/make_fate_x86 | success | Make fate finished |
Any objections to this patchset? On Sat, Feb 24, 2024 at 12:06 PM Connor Worley <connorbworley@gmail.com> wrote: > Signed-off-by: Connor Worley <connorbworley@gmail.com> > --- > libavutil/Makefile | 2 + > libavutil/hashtable.c | 192 ++++++++++++++++++++++++++++++++++++ > libavutil/hashtable.h | 40 ++++++++ > libavutil/tests/hashtable.c | 110 +++++++++++++++++++++ > 4 files changed, 344 insertions(+) > create mode 100644 libavutil/hashtable.c > create mode 100644 libavutil/hashtable.h > create mode 100644 libavutil/tests/hashtable.c > > diff --git a/libavutil/Makefile b/libavutil/Makefile > index e7709b97d0..be75d464fc 100644 > --- a/libavutil/Makefile > +++ b/libavutil/Makefile > @@ -138,6 +138,7 @@ OBJS = adler32.o > \ > fixed_dsp.o \ > frame.o \ > hash.o \ > + hashtable.o \ > hdr_dynamic_metadata.o \ > hdr_dynamic_vivid_metadata.o \ > hmac.o \ > @@ -251,6 +252,7 @@ TESTPROGS = adler32 > \ > file \ > fifo \ > hash \ > + hashtable \ > hmac \ > hwdevice \ > integer \ > diff --git a/libavutil/hashtable.c b/libavutil/hashtable.c > new file mode 100644 > index 0000000000..155a264665 > --- /dev/null > +++ b/libavutil/hashtable.c > @@ -0,0 +1,192 @@ > +/* > + * Generic hashtable > + * Copyright (C) 2024 Connor Worley <connorbworley@gmail.com> > + * > + * This file is part of FFmpeg. > + * > + * FFmpeg is free software; you can redistribute it and/or > + * modify it under the terms of the GNU Lesser General Public > + * License as published by the Free Software Foundation; either > + * version 2.1 of the License, or (at your option) any later version. > + * > + * FFmpeg 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 > + * Lesser General Public License for more details. > + * > + * You should have received a copy of the GNU Lesser General Public > + * License along with FFmpeg; if not, write to the Free Software > + * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA > 02110-1301 USA > + */ > + > +#include <stdint.h> > +#include <string.h> > + > +#include "crc.h" > +#include "error.h" > +#include "mem.h" > +#include "hashtable.h" > + > +#define ALIGN _Alignof(size_t) > + > +struct AVHashtableContext { > + size_t key_size; > + size_t key_size_aligned; > + size_t val_size; > + size_t val_size_aligned; > + size_t entry_size; > + size_t max_entries; > + size_t utilization; > + const AVCRC *crc; > + uint8_t *table; > + uint8_t *swapbuf; > +}; > + > +#define ENTRY_PSL(entry) (entry) > +#define ENTRY_OCC(entry) (ENTRY_PSL(entry) + FFALIGN(sizeof(size_t), > ALIGN)) > +#define ENTRY_KEY(entry) (ENTRY_OCC(entry) + FFALIGN(sizeof(size_t), > ALIGN)) > +#define ENTRY_VAL(entry) (ENTRY_KEY(entry) + ctx->key_size_aligned) > + > +#define KEYS_EQUAL(k1, k2) !memcmp(k1, k2, ctx->key_size) > + > +int av_hashtable_alloc(struct AVHashtableContext **ctx, size_t key_size, > size_t val_size, size_t max_entries) > +{ > + struct AVHashtableContext *res = av_malloc(sizeof(struct > AVHashtableContext)); > + if (!res) > + return AVERROR(ENOMEM); > + res->key_size = key_size; > + res->key_size_aligned = FFALIGN(key_size, ALIGN); > + res->val_size = val_size; > + res->val_size_aligned = FFALIGN(val_size, ALIGN); > + res->entry_size = FFALIGN(sizeof(size_t), ALIGN) > + + FFALIGN(sizeof(size_t), ALIGN) > + + res->key_size_aligned > + + res->val_size_aligned; > + res->max_entries = max_entries; > + res->utilization = 0; > + res->crc = av_crc_get_table(AV_CRC_32_IEEE); > + if (!res->crc) { > + av_hashtable_freep(&res); > + return AVERROR_BUG; > + } > + res->table = av_calloc(res->max_entries, res->entry_size); > + if (!res->table) { > + av_hashtable_freep(&res); > + return AVERROR(ENOMEM); > + } > + res->swapbuf = av_calloc(2, res->key_size_aligned + > res->val_size_aligned); > + if (!res->swapbuf) { > + av_hashtable_freep(&res); > + return AVERROR(ENOMEM); > + } > + *ctx = res; > + return 0; > +} > + > +static size_t hash_key(const struct AVHashtableContext *ctx, const void > *key) > +{ > + return av_crc(ctx->crc, 0, key, ctx->key_size) % ctx->max_entries; > +} > + > +int av_hashtable_get(const struct AVHashtableContext *ctx, const void > *key, void *val) > +{ > + size_t hash = hash_key(ctx, key); > + > + if (!ctx->utilization) > + return 0; > + > + for (size_t psl = 0; psl < ctx->max_entries; psl++) { > + size_t wrapped_index = (hash + psl) % ctx->max_entries; > + uint8_t *entry = ctx->table + wrapped_index * ctx->entry_size; > + if (!*ENTRY_OCC(entry) || *(size_t*)ENTRY_PSL(entry) < psl) > + return 0; > + if (KEYS_EQUAL(ENTRY_KEY(entry), key)) { > + memcpy(val, ENTRY_VAL(entry), ctx->val_size); > + return 1; > + } > + } > + return 0; > +} > + > +int av_hashtable_set(struct AVHashtableContext *ctx, const void *key, > const void *val) > +{ > + int swapping = 0; > + size_t psl = 0; > + size_t hash = hash_key(ctx, key); > + uint8_t *set = ctx->swapbuf; > + uint8_t *tmp = ctx->swapbuf + ctx->key_size_aligned + > ctx->val_size_aligned; > + > + memcpy(set, key, ctx->key_size); > + memcpy(set + ctx->key_size_aligned, val, ctx->val_size); > + > + for (size_t i = 0; i < ctx->max_entries; i++) { > + size_t wrapped_index = (hash + i) % ctx->max_entries; > + uint8_t *entry = ctx->table + wrapped_index * ctx->entry_size; > + if (!*ENTRY_OCC(entry) || (!swapping && > KEYS_EQUAL(ENTRY_KEY(entry), set))) { > + if (!*ENTRY_OCC(entry)) > + ctx->utilization++; > + *(size_t*)ENTRY_PSL(entry) = psl; > + *ENTRY_OCC(entry) = 1; > + memcpy(ENTRY_KEY(entry), set, ctx->key_size_aligned + > ctx->val_size); > + return 1; > + } > + if (*(size_t*)ENTRY_PSL(entry) < psl) { > + if (ctx->utilization == ctx->max_entries) > + return 0; > + swapping = 1; > + // set needs to swap with entry > + memcpy(tmp, ENTRY_KEY(entry), ctx->key_size_aligned + > ctx->val_size); > + memcpy(ENTRY_KEY(entry), set, ctx->key_size_aligned + > ctx->val_size); > + FFSWAP(uint8_t*, set, tmp); > + FFSWAP(size_t, psl, *(size_t*)ENTRY_PSL(entry)); > + } > + psl++; > + } > + return 0; > +} > + > +int av_hashtable_delete(struct AVHashtableContext *ctx, const void *key) > +{ > + uint8_t *next_entry; > + size_t hash = hash_key(ctx, key); > + > + if (!ctx->utilization) > + return 0; > + > + for (size_t psl = 0; psl < ctx->max_entries; psl++) { > + size_t wrapped_index = (hash + psl) % ctx->max_entries; > + uint8_t *entry = ctx->table + wrapped_index * ctx->entry_size; > + if (!*ENTRY_OCC(entry) || *(size_t*)ENTRY_PSL(entry) < psl) > + return 0; > + if (KEYS_EQUAL(ENTRY_KEY(entry), key)) { > + *ENTRY_OCC(entry) = 0; > + for (psl++; psl < ctx->max_entries; psl++) { > + wrapped_index = (hash + psl) % ctx->max_entries; > + next_entry = ctx->table + wrapped_index * ctx->entry_size; > + if (!*ENTRY_OCC(next_entry) || > !*(size_t*)ENTRY_PSL(next_entry)) { > + ctx->utilization--; > + return 1; > + } > + memcpy(entry, next_entry, ctx->entry_size); > + (*(size_t*)ENTRY_PSL(entry))--; > + *ENTRY_OCC(next_entry) = 0; > + entry = next_entry; > + } > + } > + }; > + return 0; > +} > + > +void av_hashtable_clear(struct AVHashtableContext *ctx) > +{ > + memset(ctx->table, 0, ctx->entry_size * ctx->max_entries); > +} > + > +void av_hashtable_freep(struct AVHashtableContext **ctx) > +{ > + if (*ctx) { > + av_freep(&(*ctx)->table); > + av_freep(&(*ctx)->swapbuf); > + } > + av_freep(ctx); > +} > diff --git a/libavutil/hashtable.h b/libavutil/hashtable.h > new file mode 100644 > index 0000000000..f14086867e > --- /dev/null > +++ b/libavutil/hashtable.h > @@ -0,0 +1,40 @@ > +/* > + * Generic hashtable > + * Copyright (C) 2024 Connor Worley <connorbworley@gmail.com> > + * > + * This file is part of FFmpeg. > + * > + * FFmpeg is free software; you can redistribute it and/or > + * modify it under the terms of the GNU Lesser General Public > + * License as published by the Free Software Foundation; either > + * version 2.1 of the License, or (at your option) any later version. > + * > + * FFmpeg 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 > + * Lesser General Public License for more details. > + * > + * You should have received a copy of the GNU Lesser General Public > + * License along with FFmpeg; if not, write to the Free Software > + * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA > 02110-1301 USA > + */ > + > +#ifndef AVUTIL_HASHTABLE_H > +#define AVUTIL_HASHTABLE_H > + > +#include <stddef.h> > + > +/* Implements a hash table using Robin Hood open addressing. > + * See: https://cs.uwaterloo.ca/research/tr/1986/CS-86-14.pdf > + */ > + > +struct AVHashtableContext; > + > +int av_hashtable_alloc(struct AVHashtableContext **ctx, size_t key_size, > size_t val_size, size_t max_entries); > +int av_hashtable_get(const struct AVHashtableContext *ctx, const void > *key, void *val); > +int av_hashtable_set(struct AVHashtableContext *ctx, const void *key, > const void *val); > +int av_hashtable_delete(struct AVHashtableContext *ctx, const void *key); > +void av_hashtable_clear(struct AVHashtableContext *ctx); > +void av_hashtable_freep(struct AVHashtableContext **ctx); > + > +#endif > diff --git a/libavutil/tests/hashtable.c b/libavutil/tests/hashtable.c > new file mode 100644 > index 0000000000..1e37d7663b > --- /dev/null > +++ b/libavutil/tests/hashtable.c > @@ -0,0 +1,110 @@ > +/* > + * Generic hashtable tests > + * Copyright (C) 2024 Connor Worley <connorbworley@gmail.com> > + * > + * This file is part of FFmpeg. > + * > + * FFmpeg is free software; you can redistribute it and/or > + * modify it under the terms of the GNU Lesser General Public > + * License as published by the Free Software Foundation; either > + * version 2.1 of the License, or (at your option) any later version. > + * > + * FFmpeg 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 > + * Lesser General Public License for more details. > + * > + * You should have received a copy of the GNU Lesser General Public > + * License along with FFmpeg; if not, write to the Free Software > + * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA > 02110-1301 USA > + */ > + > +#include <stdint.h> > + > +#include "libavutil/avassert.h" > +#include "libavutil/hashtable.h" > + > +int main(void) > +{ > + struct AVHashtableContext *ctx; > + uint8_t k; > + uint64_t v; > + > + // impossibly large allocation should fail gracefully > + av_assert0(av_hashtable_alloc(&ctx, -1, -1, -1) < 0); > + > + // hashtable can store up to 3 uint8_t->uint64_t entries > + av_assert0(!av_hashtable_alloc(&ctx, sizeof(k), sizeof(v), 3)); > + > + // unsuccessful deletes return 0 > + k = 1; > + av_assert0(!av_hashtable_delete(ctx, &k)); > + > + // unsuccessful gets return 0 > + k = 1; > + av_assert0(!av_hashtable_get(ctx, &k, &v)); > + > + // successful sets returns 1 > + k = 1; > + v = 1; > + av_assert0(av_hashtable_set(ctx, &k, &v)); > + > + // get should now contain 1 > + k = 1; > + v = 0; > + av_assert0(av_hashtable_get(ctx, &k, &v)); > + av_assert0(v == 1); > + > + // updating sets should return 1 > + k = 1; > + v = 2; > + av_assert0(av_hashtable_set(ctx, &k, &v)); > + > + // get should now contain 2 > + k = 1; > + v = 0; > + av_assert0(av_hashtable_get(ctx, &k, &v)); > + av_assert0(v == 2); > + > + // fill the table > + k = 2; > + v = 2; > + av_assert0(av_hashtable_set(ctx, &k, &v)); > + k = 3; > + v = 3; > + av_assert0(av_hashtable_set(ctx, &k, &v)); > + > + // inserting sets on a full table should return 0 > + k = 4; > + v = 4; > + av_assert0(!av_hashtable_set(ctx, &k, &v)); > + > + // updating sets on a full table should return 1 > + k = 1; > + v = 4; > + av_assert0(av_hashtable_set(ctx, &k, &v)); > + v = 0; > + av_assert0(av_hashtable_get(ctx, &k, &v)); > + av_assert0(v == 4); > + > + // successful deletes should return 1 > + k = 1; > + av_assert0(av_hashtable_delete(ctx, &k)); > + > + // get should now return 0 > + av_assert0(!av_hashtable_get(ctx, &k, &v)); > + > + // sanity check remaining keys > + k = 2; > + v = 0; > + av_assert0(av_hashtable_get(ctx, &k, &v)); > + av_assert0(v == 2); > + k = 3; > + v = 0; > + av_assert0(av_hashtable_get(ctx, &k, &v)); > + av_assert0(v == 3); > + > + av_hashtable_freep(&ctx); > + > + return 0; > +} > -- > 2.43.1 > >
Quoting Connor Worley (2024-03-03 23:44:55)
> Any objections to this patchset?
Lack of documentation, for one thing.
diff --git a/libavutil/Makefile b/libavutil/Makefile index e7709b97d0..be75d464fc 100644 --- a/libavutil/Makefile +++ b/libavutil/Makefile @@ -138,6 +138,7 @@ OBJS = adler32.o \ fixed_dsp.o \ frame.o \ hash.o \ + hashtable.o \ hdr_dynamic_metadata.o \ hdr_dynamic_vivid_metadata.o \ hmac.o \ @@ -251,6 +252,7 @@ TESTPROGS = adler32 \ file \ fifo \ hash \ + hashtable \ hmac \ hwdevice \ integer \ diff --git a/libavutil/hashtable.c b/libavutil/hashtable.c new file mode 100644 index 0000000000..155a264665 --- /dev/null +++ b/libavutil/hashtable.c @@ -0,0 +1,192 @@ +/* + * Generic hashtable + * Copyright (C) 2024 Connor Worley <connorbworley@gmail.com> + * + * This file is part of FFmpeg. + * + * FFmpeg is free software; you can redistribute it and/or + * modify it under the terms of the GNU Lesser General Public + * License as published by the Free Software Foundation; either + * version 2.1 of the License, or (at your option) any later version. + * + * FFmpeg 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 + * Lesser General Public License for more details. + * + * You should have received a copy of the GNU Lesser General Public + * License along with FFmpeg; if not, write to the Free Software + * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA + */ + +#include <stdint.h> +#include <string.h> + +#include "crc.h" +#include "error.h" +#include "mem.h" +#include "hashtable.h" + +#define ALIGN _Alignof(size_t) + +struct AVHashtableContext { + size_t key_size; + size_t key_size_aligned; + size_t val_size; + size_t val_size_aligned; + size_t entry_size; + size_t max_entries; + size_t utilization; + const AVCRC *crc; + uint8_t *table; + uint8_t *swapbuf; +}; + +#define ENTRY_PSL(entry) (entry) +#define ENTRY_OCC(entry) (ENTRY_PSL(entry) + FFALIGN(sizeof(size_t), ALIGN)) +#define ENTRY_KEY(entry) (ENTRY_OCC(entry) + FFALIGN(sizeof(size_t), ALIGN)) +#define ENTRY_VAL(entry) (ENTRY_KEY(entry) + ctx->key_size_aligned) + +#define KEYS_EQUAL(k1, k2) !memcmp(k1, k2, ctx->key_size) + +int av_hashtable_alloc(struct AVHashtableContext **ctx, size_t key_size, size_t val_size, size_t max_entries) +{ + struct AVHashtableContext *res = av_malloc(sizeof(struct AVHashtableContext)); + if (!res) + return AVERROR(ENOMEM); + res->key_size = key_size; + res->key_size_aligned = FFALIGN(key_size, ALIGN); + res->val_size = val_size; + res->val_size_aligned = FFALIGN(val_size, ALIGN); + res->entry_size = FFALIGN(sizeof(size_t), ALIGN) + + FFALIGN(sizeof(size_t), ALIGN) + + res->key_size_aligned + + res->val_size_aligned; + res->max_entries = max_entries; + res->utilization = 0; + res->crc = av_crc_get_table(AV_CRC_32_IEEE); + if (!res->crc) { + av_hashtable_freep(&res); + return AVERROR_BUG; + } + res->table = av_calloc(res->max_entries, res->entry_size); + if (!res->table) { + av_hashtable_freep(&res); + return AVERROR(ENOMEM); + } + res->swapbuf = av_calloc(2, res->key_size_aligned + res->val_size_aligned); + if (!res->swapbuf) { + av_hashtable_freep(&res); + return AVERROR(ENOMEM); + } + *ctx = res; + return 0; +} + +static size_t hash_key(const struct AVHashtableContext *ctx, const void *key) +{ + return av_crc(ctx->crc, 0, key, ctx->key_size) % ctx->max_entries; +} + +int av_hashtable_get(const struct AVHashtableContext *ctx, const void *key, void *val) +{ + size_t hash = hash_key(ctx, key); + + if (!ctx->utilization) + return 0; + + for (size_t psl = 0; psl < ctx->max_entries; psl++) { + size_t wrapped_index = (hash + psl) % ctx->max_entries; + uint8_t *entry = ctx->table + wrapped_index * ctx->entry_size; + if (!*ENTRY_OCC(entry) || *(size_t*)ENTRY_PSL(entry) < psl) + return 0; + if (KEYS_EQUAL(ENTRY_KEY(entry), key)) { + memcpy(val, ENTRY_VAL(entry), ctx->val_size); + return 1; + } + } + return 0; +} + +int av_hashtable_set(struct AVHashtableContext *ctx, const void *key, const void *val) +{ + int swapping = 0; + size_t psl = 0; + size_t hash = hash_key(ctx, key); + uint8_t *set = ctx->swapbuf; + uint8_t *tmp = ctx->swapbuf + ctx->key_size_aligned + ctx->val_size_aligned; + + memcpy(set, key, ctx->key_size); + memcpy(set + ctx->key_size_aligned, val, ctx->val_size); + + for (size_t i = 0; i < ctx->max_entries; i++) { + size_t wrapped_index = (hash + i) % ctx->max_entries; + uint8_t *entry = ctx->table + wrapped_index * ctx->entry_size; + if (!*ENTRY_OCC(entry) || (!swapping && KEYS_EQUAL(ENTRY_KEY(entry), set))) { + if (!*ENTRY_OCC(entry)) + ctx->utilization++; + *(size_t*)ENTRY_PSL(entry) = psl; + *ENTRY_OCC(entry) = 1; + memcpy(ENTRY_KEY(entry), set, ctx->key_size_aligned + ctx->val_size); + return 1; + } + if (*(size_t*)ENTRY_PSL(entry) < psl) { + if (ctx->utilization == ctx->max_entries) + return 0; + swapping = 1; + // set needs to swap with entry + memcpy(tmp, ENTRY_KEY(entry), ctx->key_size_aligned + ctx->val_size); + memcpy(ENTRY_KEY(entry), set, ctx->key_size_aligned + ctx->val_size); + FFSWAP(uint8_t*, set, tmp); + FFSWAP(size_t, psl, *(size_t*)ENTRY_PSL(entry)); + } + psl++; + } + return 0; +} + +int av_hashtable_delete(struct AVHashtableContext *ctx, const void *key) +{ + uint8_t *next_entry; + size_t hash = hash_key(ctx, key); + + if (!ctx->utilization) + return 0; + + for (size_t psl = 0; psl < ctx->max_entries; psl++) { + size_t wrapped_index = (hash + psl) % ctx->max_entries; + uint8_t *entry = ctx->table + wrapped_index * ctx->entry_size; + if (!*ENTRY_OCC(entry) || *(size_t*)ENTRY_PSL(entry) < psl) + return 0; + if (KEYS_EQUAL(ENTRY_KEY(entry), key)) { + *ENTRY_OCC(entry) = 0; + for (psl++; psl < ctx->max_entries; psl++) { + wrapped_index = (hash + psl) % ctx->max_entries; + next_entry = ctx->table + wrapped_index * ctx->entry_size; + if (!*ENTRY_OCC(next_entry) || !*(size_t*)ENTRY_PSL(next_entry)) { + ctx->utilization--; + return 1; + } + memcpy(entry, next_entry, ctx->entry_size); + (*(size_t*)ENTRY_PSL(entry))--; + *ENTRY_OCC(next_entry) = 0; + entry = next_entry; + } + } + }; + return 0; +} + +void av_hashtable_clear(struct AVHashtableContext *ctx) +{ + memset(ctx->table, 0, ctx->entry_size * ctx->max_entries); +} + +void av_hashtable_freep(struct AVHashtableContext **ctx) +{ + if (*ctx) { + av_freep(&(*ctx)->table); + av_freep(&(*ctx)->swapbuf); + } + av_freep(ctx); +} diff --git a/libavutil/hashtable.h b/libavutil/hashtable.h new file mode 100644 index 0000000000..f14086867e --- /dev/null +++ b/libavutil/hashtable.h @@ -0,0 +1,40 @@ +/* + * Generic hashtable + * Copyright (C) 2024 Connor Worley <connorbworley@gmail.com> + * + * This file is part of FFmpeg. + * + * FFmpeg is free software; you can redistribute it and/or + * modify it under the terms of the GNU Lesser General Public + * License as published by the Free Software Foundation; either + * version 2.1 of the License, or (at your option) any later version. + * + * FFmpeg 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 + * Lesser General Public License for more details. + * + * You should have received a copy of the GNU Lesser General Public + * License along with FFmpeg; if not, write to the Free Software + * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA + */ + +#ifndef AVUTIL_HASHTABLE_H +#define AVUTIL_HASHTABLE_H + +#include <stddef.h> + +/* Implements a hash table using Robin Hood open addressing. + * See: https://cs.uwaterloo.ca/research/tr/1986/CS-86-14.pdf + */ + +struct AVHashtableContext; + +int av_hashtable_alloc(struct AVHashtableContext **ctx, size_t key_size, size_t val_size, size_t max_entries); +int av_hashtable_get(const struct AVHashtableContext *ctx, const void *key, void *val); +int av_hashtable_set(struct AVHashtableContext *ctx, const void *key, const void *val); +int av_hashtable_delete(struct AVHashtableContext *ctx, const void *key); +void av_hashtable_clear(struct AVHashtableContext *ctx); +void av_hashtable_freep(struct AVHashtableContext **ctx); + +#endif diff --git a/libavutil/tests/hashtable.c b/libavutil/tests/hashtable.c new file mode 100644 index 0000000000..1e37d7663b --- /dev/null +++ b/libavutil/tests/hashtable.c @@ -0,0 +1,110 @@ +/* + * Generic hashtable tests + * Copyright (C) 2024 Connor Worley <connorbworley@gmail.com> + * + * This file is part of FFmpeg. + * + * FFmpeg is free software; you can redistribute it and/or + * modify it under the terms of the GNU Lesser General Public + * License as published by the Free Software Foundation; either + * version 2.1 of the License, or (at your option) any later version. + * + * FFmpeg 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 + * Lesser General Public License for more details. + * + * You should have received a copy of the GNU Lesser General Public + * License along with FFmpeg; if not, write to the Free Software + * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA + */ + +#include <stdint.h> + +#include "libavutil/avassert.h" +#include "libavutil/hashtable.h" + +int main(void) +{ + struct AVHashtableContext *ctx; + uint8_t k; + uint64_t v; + + // impossibly large allocation should fail gracefully + av_assert0(av_hashtable_alloc(&ctx, -1, -1, -1) < 0); + + // hashtable can store up to 3 uint8_t->uint64_t entries + av_assert0(!av_hashtable_alloc(&ctx, sizeof(k), sizeof(v), 3)); + + // unsuccessful deletes return 0 + k = 1; + av_assert0(!av_hashtable_delete(ctx, &k)); + + // unsuccessful gets return 0 + k = 1; + av_assert0(!av_hashtable_get(ctx, &k, &v)); + + // successful sets returns 1 + k = 1; + v = 1; + av_assert0(av_hashtable_set(ctx, &k, &v)); + + // get should now contain 1 + k = 1; + v = 0; + av_assert0(av_hashtable_get(ctx, &k, &v)); + av_assert0(v == 1); + + // updating sets should return 1 + k = 1; + v = 2; + av_assert0(av_hashtable_set(ctx, &k, &v)); + + // get should now contain 2 + k = 1; + v = 0; + av_assert0(av_hashtable_get(ctx, &k, &v)); + av_assert0(v == 2); + + // fill the table + k = 2; + v = 2; + av_assert0(av_hashtable_set(ctx, &k, &v)); + k = 3; + v = 3; + av_assert0(av_hashtable_set(ctx, &k, &v)); + + // inserting sets on a full table should return 0 + k = 4; + v = 4; + av_assert0(!av_hashtable_set(ctx, &k, &v)); + + // updating sets on a full table should return 1 + k = 1; + v = 4; + av_assert0(av_hashtable_set(ctx, &k, &v)); + v = 0; + av_assert0(av_hashtable_get(ctx, &k, &v)); + av_assert0(v == 4); + + // successful deletes should return 1 + k = 1; + av_assert0(av_hashtable_delete(ctx, &k)); + + // get should now return 0 + av_assert0(!av_hashtable_get(ctx, &k, &v)); + + // sanity check remaining keys + k = 2; + v = 0; + av_assert0(av_hashtable_get(ctx, &k, &v)); + av_assert0(v == 2); + k = 3; + v = 0; + av_assert0(av_hashtable_get(ctx, &k, &v)); + av_assert0(v == 3); + + av_hashtable_freep(&ctx); + + return 0; +}
Signed-off-by: Connor Worley <connorbworley@gmail.com> --- libavutil/Makefile | 2 + libavutil/hashtable.c | 192 ++++++++++++++++++++++++++++++++++++ libavutil/hashtable.h | 40 ++++++++ libavutil/tests/hashtable.c | 110 +++++++++++++++++++++ 4 files changed, 344 insertions(+) create mode 100644 libavutil/hashtable.c create mode 100644 libavutil/hashtable.h create mode 100644 libavutil/tests/hashtable.c