On Tue, 29 Sep 2020 16:41:13 +0300
"Yordan Karadzhov (VMware)" <y.karadz@xxxxxxxxx> wrote:
> +/**
> + * Create new hash table of Ids.
> + */
> +struct kshark_hash_id *kshark_hash_id_alloc(size_t n_bits)
> +{
> + struct kshark_hash_id *hash;
> + size_t size;
> +
> + hash = calloc(1, sizeof(*hash));
> + assert(hash);
For failed memory, is the general plan to just crash? (assert) or return
NULL?
> +
> + hash->n_bits = n_bits;
> + hash->count = 0;
> +
> + size = hash_size(hash);
> + hash->hash = calloc(size, sizeof(*hash->hash));
In either case, this needs to be checked too.
> +
> + return hash;
> +}
> +
> +/** Free the hash table of Ids. */
> +void kshark_hash_id_free(struct kshark_hash_id *hash)
> +{
> + if (!hash)
> + return;
> +
> + kshark_hash_id_clear(hash);
> + free(hash->hash);
> + free(hash);
> +}
> +
> diff --git a/src/libkshark.h b/src/libkshark.h
> index 9eecc2d..57bd5e5 100644
> --- a/src/libkshark.h
> +++ b/src/libkshark.h
> @@ -33,6 +33,7 @@ extern "C" {
> // KernelShark
> #include "libkshark-plugin.h"
>
> +
Extra white space.
> /**
> * Kernel Shark entry contains all information from one trace record needed
> * in order to visualize the time-series of trace records. The part of the
> @@ -72,6 +73,52 @@ struct kshark_entry {
> int64_t ts;
> };
>
> +/** Size of the task'c hash table in terms of bits being used by the key. */
"task'c" ?
-- Steve
> +#define KS_TASK_HASH_NBITS 16
> +
> +/** Size of the hash table of Ids in terms of bits being used by the key. */
> +#define KS_FILTER_HASH_NBITS 8
> +
> +/** A bucket for the hash table of integer Id numbers (kshark_hash_id). */
> +struct kshark_hash_id_item {
> + /** Pointer to the Id in this bucket. */
> + struct kshark_hash_id_item *next;
> +
> + /** The Id value. */
> + int id;
> +};
> +
> +/**
> + * Hash table of integer Id numbers. To be used for fast filter of trace
> + * entries.
> + */
> +struct kshark_hash_id {
> + /** Array of buckets. */
> + struct kshark_hash_id_item **hash;
> +
> + /** The number of Ids in the table. */
> + size_t count;
> +
> + /**
> + * The number of bits used by the hashing function.
> + * Note that the number of buckets in the table if given by
> + * 1 << n_bits.
> + */
> + size_t n_bits;
> +};
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