Re: [PATCH 2/2] fast-import: use struct hash_table for objects
From: Jonathan Nieder <hidden>
Date: 2016-06-15 22:50:57
David Barr wrote:
Signed-off-by: David Barr <redacted>
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).
quoted hunk ↗ jump to hunk
--- 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).
quoted hunk ↗ jump to hunk
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