Re: [PATCH 2/2] fast-import: use struct hash_table for objects
- From
Jonathan Nieder <jrnieder@gmail.com>
- Date
- Apr 2, 2011, 02:46 UTC
- Message-ID
- <20110402024636.GB6039@elie>
- In-Reply-To
- <1301572798-9973-3-git-send-email-david.barr@cordelta.com>
David Barr wrote:
> Signed-off-by: David Barr <david.barr@cordelta.com>
Thanks, this one is even more welcome. :) Same comments as the other patch apply. Keeping the patch in full below so others can comment.
One comment below (search for object.c to find it; sorry).
Show 38 quoted lines
> ---
> fast-import.c | 19 ++++++++++++-------
> 1 files changed, 12 insertions(+), 7 deletions(-)
>
> diff --git a/fast-import.c b/fast-import.c
> index 0592b21..8fd8ea9 100644
> --- a/fast-import.c
> +++ b/fast-import.c
> @@ -313,7 +313,7 @@ static off_t pack_size;
> /* Table of objects we've written. */
> static unsigned int object_entry_alloc = 5000;
> static struct object_entry_pool *blocks;
> -static struct object_entry *object_table[1 << 16];
> +static struct hash_table object_table;
> static struct mark_set *marks;
> static const char *export_marks_file;
> static const char *import_marks_file;
> @@ -555,9 +555,9 @@ static struct object_entry *new_object(unsigned char *sha1)
>
> static struct object_entry *find_object(unsigned char *sha1)
> {
> - unsigned int h = sha1[0] << 8 | sha1[1];
> + unsigned int h = sha1[0] << 24 | sha1[1] << 16 | sha1[2] << 8 | sha1[3];
> struct object_entry *e;
> - for (e = object_table[h]; e; e = e->next)
> + for (e = lookup_hash(h, &object_table); e; e = e->next)
> if (!hashcmp(sha1, e->idx.sha1))
> return e;
> return NULL;
> @@ -565,8 +565,9 @@ static struct object_entry *find_object(unsigned char *sha1)
>
> static struct object_entry *insert_object(unsigned char *sha1)
> {
> - unsigned int h = sha1[0] << 8 | sha1[1];
> - struct object_entry *e = object_table[h];
> + unsigned int h = sha1[0] << 24 | sha1[1] << 16 | sha1[2] << 8 | sha1[3];
> + struct object_entry *e = lookup_hash(h, &object_table);
> + void **pos;object.c uses memcpy for this, like so:
memcpy(&h, sha1, sizeof(unsigned int));
which strikes me as sensible (to avoid fighting with the machine about endianness since this table is only in memory).
Show 22 quoted lines
>
> while (e) {
> if (!hashcmp(sha1, e->idx.sha1))
> @@ -575,9 +576,13 @@ static struct object_entry *insert_object(unsigned char *sha1)
> }
>
> e = new_object(sha1);
> - e->next = object_table[h];
> + e->next = NULL;
> e->idx.offset = 0;
> - object_table[h] = e;
> + pos = insert_hash(h, e, &object_table);
> + if (pos) {
> + e->next = *pos;
> + *pos = e;
> + }
> return e;
> }
>
> --
> 1.7.3.2.846.gf4b062
>