[igt-dev] [PATCH i-g-t v23 04/37] lib/igt_map: Introduce igt_map

Daniel Vetter daniel at ffwll.ch
Tue Mar 16 10:30:39 UTC 2021


On Mon, Mar 15, 2021 at 05:58:09PM +0100, Zbigniew Kempczyński wrote:
> From: Dominik Grzegorzek <dominik.grzegorzek at intel.com>
> 
> Implementation of generic, non-thread safe, dynamic size hash map.
> 
> Signed-off-by: Dominik Grzegorzek <dominik.grzegorzek at intel.com>
> Cc: Zbigniew Kempczyński <zbigniew.kempczynski at intel.com>
> Cc: Chris Wilson <chris at chris-wilson.co.uk>
> ---
>  .../igt-gpu-tools/igt-gpu-tools-docs.xml      |   1 +

Similar here, there's a solid intro, that's good. But we try to at least
doc all the non-static functions that tests can use.
-Daniel

>  lib/Makefile.sources                          |   2 +
>  lib/igt_map.c                                 | 131 ++++++++++++++++++
>  lib/igt_map.h                                 | 104 ++++++++++++++
>  lib/meson.build                               |   1 +
>  5 files changed, 239 insertions(+)
>  create mode 100644 lib/igt_map.c
>  create mode 100644 lib/igt_map.h
> 
> diff --git a/docs/reference/igt-gpu-tools/igt-gpu-tools-docs.xml b/docs/reference/igt-gpu-tools/igt-gpu-tools-docs.xml
> index 9c9aa8f1d..bf5ac5428 100644
> --- a/docs/reference/igt-gpu-tools/igt-gpu-tools-docs.xml
> +++ b/docs/reference/igt-gpu-tools/igt-gpu-tools-docs.xml
> @@ -33,6 +33,7 @@
>      <xi:include href="xml/igt_kmod.xml"/>
>      <xi:include href="xml/igt_kms.xml"/>
>      <xi:include href="xml/igt_list.xml"/>
> +    <xi:include href="xml/igt_map.xml"/>
>      <xi:include href="xml/igt_pm.xml"/>
>      <xi:include href="xml/igt_primes.xml"/>
>      <xi:include href="xml/igt_rand.xml"/>
> diff --git a/lib/Makefile.sources b/lib/Makefile.sources
> index 4f6389f8a..84fd7b49c 100644
> --- a/lib/Makefile.sources
> +++ b/lib/Makefile.sources
> @@ -48,6 +48,8 @@ lib_source_list =	 	\
>  	igt_infoframe.h		\
>  	igt_list.c		\
>  	igt_list.h		\
> +	igt_map.c		\
> +	igt_map.h		\
>  	igt_matrix.c		\
>  	igt_matrix.h		\
>  	igt_params.c		\
> diff --git a/lib/igt_map.c b/lib/igt_map.c
> new file mode 100644
> index 000000000..12909ed5a
> --- /dev/null
> +++ b/lib/igt_map.c
> @@ -0,0 +1,131 @@
> +// SPDX-License-Identifier: MIT
> +/*
> + * Copyright © 2021 Intel Corporation
> + */
> +
> +#include <sys/ioctl.h>
> +#include <stdlib.h>
> +#include "igt_map.h"
> +#include "igt.h"
> +#include "igt_x86.h"
> +
> +#define MIN_CAPACITY_BITS 2
> +
> +static bool igt_map_filled(struct igt_map *map)
> +{
> +	return IGT_MAP_CAPACITY(map) * 4 / 5 <= map->size;
> +}
> +
> +static void igt_map_extend(struct igt_map *map)
> +{
> +	struct igt_hlist_head *new_heads;
> +	struct igt_map_entry *pos;
> +	struct igt_hlist_node *tmp;
> +	uint32_t new_bits = map->capacity_bits + 1;
> +	int i;
> +
> +	new_heads = calloc(1ULL << new_bits,
> +			   sizeof(struct igt_hlist_head));
> +	igt_assert(new_heads);
> +
> +	igt_map_for_each_safe(map, i, tmp, pos)
> +		igt_hlist_add_head(&pos->link, &new_heads[map->hash_fn(pos->key, new_bits)]);
> +
> +	free(map->heads);
> +	map->capacity_bits++;
> +
> +	map->heads = new_heads;
> +}
> +
> +static bool equal_4bytes(const void *key1, const void *key2)
> +{
> +	const uint32_t *k1 = key1, *k2 = key2;
> +	return *k1 == *k2;
> +}
> +
> +/*  2^63 + 2^61 - 2^57 + 2^54 - 2^51 - 2^18 + 1 */
> +#define GOLDEN_RATIO_PRIME_64 0x9e37fffffffc0001ULL
> +
> +static inline uint64_t hash_64_4bytes(const void *val, unsigned int bits)
> +{
> +	uint64_t hash = *(uint32_t *)val;
> +
> +	hash = hash * GOLDEN_RATIO_PRIME_64;
> +	/* High bits are more random, so use them. */
> +	return hash >> (64 - bits);
> +}
> +
> +void __igt_map_init(struct igt_map *map, igt_map_equal_fn eq_fn,
> +		    igt_map_hash_fn hash_fn, uint32_t initial_bits)
> +{
> +	map->equal_fn = eq_fn == NULL ? equal_4bytes : eq_fn;
> +	map->hash_fn = hash_fn == NULL ? hash_64_4bytes : hash_fn;
> +	map->capacity_bits = initial_bits > 0 ? initial_bits
> +					      : MIN_CAPACITY_BITS;
> +	map->heads = calloc(IGT_MAP_CAPACITY(map),
> +			    sizeof(struct igt_hlist_head));
> +
> +	igt_assert(map->heads);
> +	map->size = 0;
> +}
> +
> +void igt_map_add(struct igt_map *map, const void *key, void *value)
> +{
> +	struct igt_map_entry *entry;
> +
> +	if (igt_map_filled(map))
> +		igt_map_extend(map);
> +
> +	entry = malloc(sizeof(struct igt_map_entry));
> +	entry->value = value;
> +	entry->key = key;
> +	igt_hlist_add_head(&entry->link,
> +			   &map->heads[map->hash_fn(key, map->capacity_bits)]);
> +	map->size++;
> +}
> +
> +void *igt_map_del(struct igt_map *map, const void *key)
> +{
> +	struct igt_map_entry *pos;
> +	struct igt_hlist_node *tmp;
> +	void *val = NULL;
> +
> +	igt_map_for_each_possible_safe(map, pos, tmp, key) {
> +		if (map->equal_fn(pos->key, key)) {
> +			igt_hlist_del(&pos->link);
> +			val = pos->value;
> +			free(pos);
> +		}
> +	}
> +	return val;
> +}
> +
> +void *igt_map_find(struct igt_map *map, const void *key)
> +{
> +	struct igt_map_entry *pos = NULL;
> +
> +	igt_map_for_each_possible(map, pos, key)
> +		if (map->equal_fn(pos->key, key))
> +			break;
> +
> +	return pos ? pos->value : NULL;
> +}
> +
> +void igt_map_free(struct igt_map *map)
> +{
> +	struct igt_map_entry *pos;
> +	struct igt_hlist_node *tmp;
> +	int i;
> +
> +	igt_map_for_each_safe(map, i, tmp, pos) {
> +		igt_hlist_del(&pos->link);
> +		free(pos);
> +	}
> +
> +	free(map->heads);
> +}
> +
> +bool igt_map_empty(struct igt_map *map)
> +{
> +	return map->size;
> +}
> diff --git a/lib/igt_map.h b/lib/igt_map.h
> new file mode 100644
> index 000000000..d47afdbbe
> --- /dev/null
> +++ b/lib/igt_map.h
> @@ -0,0 +1,104 @@
> +// SPDX-License-Identifier: MIT
> +/*
> + * Copyright © 2021 Intel Corporation
> + */
> +
> +#ifndef IGT_MAP_H
> +#define IGT_MAP_H
> +
> +#include <stdint.h>
> +#include "igt_list.h"
> +
> +/**
> + * SECTION:igt_map
> + * @short_description: a dynamic sized hashmap implementation
> + * @title: IGT Map
> + * @include: igt_map.h
> + *
> + * igt_map is a dynamic sized, non-thread-safe implementation of a hashmap.
> + * This map grows exponentially when it's over 80% filled. The structure allows
> + * indexing records by any key through the hash and equal functions.
> + * By default, hashmap compares and hashes the first four bytes of a key.
> + *
> + * Example usage:
> + *
> + * |[<!-- language="C" -->
> + * struct igt_map *map;
> + *
> + * struct record {
> + *      int foo;
> + *      uint32_t unique_identifier;
> + * };
> + *
> + * struct record r1, r2, *r_ptr;
> + *
> + * map = malloc(sizeof(*map));
> + * igt_map_init(map); // initiaize the map with default parameters
> + * igt_map_add(map, &r1.unique_identifier, &r1);
> + * igt_map_add(map, &r2.unique_identifier, &r2);
> + *
> + * struct igt_map_entry *pos; int i;
> + * igt_map_for_each(map, i, pos) {
> + *      r_ptr = pos->value;
> + *      printf("key: %u, foo: %d\n", *(uint32_t*) pos->key, r_ptr->foo);
> + * }
> + *
> + * uint32_t key = r1.unique_identifier;
> + * r_ptr = igt_map_find(map, &key); // get r1
> + *
> + * r_ptr = igt_map_del(map, &r2.unique_identifier);
> + * if (r_ptr)
> + *      printf("record with key %u deleted\n", r_ptr->unique_identifier);
> + *
> + * igt_map_free(map);
> + * free(map);
> + * ]|
> + */
> +
> +typedef bool (*igt_map_equal_fn)(const void *key1, const void *key2);
> +typedef uint64_t (*igt_map_hash_fn)(const void *val, unsigned int bits);
> +struct igt_map {
> +	uint32_t size;
> +	uint32_t capacity_bits;
> +	igt_map_equal_fn equal_fn;
> +	igt_map_hash_fn hash_fn;
> +	struct igt_hlist_head *heads;
> +};
> +
> +struct igt_map_entry {
> +	const void *key;
> +	void *value;
> +	struct igt_hlist_node link;
> +};
> +
> +void __igt_map_init(struct igt_map *map, igt_map_equal_fn eq_fn,
> +		  igt_map_hash_fn hash_fn, uint32_t initial_bits);
> +void igt_map_add(struct igt_map *map, const void *key, void *value);
> +void *igt_map_del(struct igt_map *map, const void *key);
> +void *igt_map_find(struct igt_map *map, const void *key);
> +void igt_map_free(struct igt_map *map);
> +bool igt_map_empty(struct igt_map *map);
> +
> +#define igt_map_init(map) __igt_map_init(map, NULL, NULL, 8)
> +
> +#define IGT_MAP_CAPACITY(map) (1ULL << map->capacity_bits)
> +
> +#define igt_map_for_each_safe(map, bkt, tmp, obj) \
> +	for ((bkt) = 0, obj = NULL; obj == NULL && (bkt) < IGT_MAP_CAPACITY(map); \
> +	(bkt)++)\
> +	igt_hlist_for_each_entry_safe(obj, tmp, &map->heads[bkt], link)
> +
> +#define igt_map_for_each(map, bkt, obj) \
> +	for ((bkt) = 0, obj = NULL; obj == NULL && (bkt) < IGT_MAP_CAPACITY(map); \
> +	(bkt)++)\
> +	igt_hlist_for_each_entry(obj, &map->heads[bkt], link)
> +
> +#define igt_map_for_each_possible(map, obj, key) \
> +	igt_hlist_for_each_entry(obj, \
> +		&map->heads[map->hash_fn(key, map->capacity_bits)], link)
> +
> +#define igt_map_for_each_possible_safe(map, obj, tmp, key) \
> +	igt_hlist_for_each_entry_safe(obj, tmp, \
> +		&map->heads[map->hash_fn(key, map->capacity_bits)], link)
> +
> +#endif /* IGT_MAP_H */
> diff --git a/lib/meson.build b/lib/meson.build
> index 672b42062..7254faeac 100644
> --- a/lib/meson.build
> +++ b/lib/meson.build
> @@ -61,6 +61,7 @@ lib_sources = [
>  	'igt_core.c',
>  	'igt_draw.c',
>  	'igt_list.c',
> +	'igt_map.c',
>  	'igt_pm.c',
>  	'igt_dummyload.c',
>  	'uwildmat/uwildmat.c',
> -- 
> 2.26.0
> 
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> igt-dev at lists.freedesktop.org
> https://lists.freedesktop.org/mailman/listinfo/igt-dev

-- 
Daniel Vetter
Software Engineer, Intel Corporation
http://blog.ffwll.ch


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