Re: [RFH] two and half potential fixlets to the in-core index handling
From: Linus Torvalds <torvalds@linux-foundation.org>
Date: 2016-06-15 22:45:13
Subsystem:
the rest · Maintainer:
Linus Torvalds
Possibly related (same subject, not in this thread)
- 2016-06-15 · Re: [RFH] two and half potential fixlets to the in-core index handling · Junio C Hamano <hidden>
- 2016-06-15 · Re: [RFH] two and half potential fixlets to the in-core index handling · Junio C Hamano <hidden>
On Sat, 23 Aug 2008, Junio C Hamano wrote:
A hacky solution I have in the attached patch is to waste an xmalloc(1) and store it there when o->result is created, and also make read_from_index() pay attention to the cache_nr and the cache_changed bit. I think it is the safest and minimum fix.
Hmm. Wouldn't it be nicer to just add another bit to istate? We have the space already, since we already have a bitfield there, with just one bit used? Something like this.. Untested. Of course. Linus --- cache.h | 3 ++- read-cache.c | 4 +++- unpack-trees.c | 1 + 3 files changed, 6 insertions(+), 2 deletions(-)
diff --git a/cache.h b/cache.h
index 68ce6e6..6e41ec4 100644
--- a/cache.h
+++ b/cache.h@@ -222,7 +222,8 @@ struct index_state { struct cache_tree *cache_tree; time_t timestamp; void *alloc; - unsigned name_hash_initialized : 1; + unsigned name_hash_initialized : 1, + initialized : 1; struct hash_table name_hash; };
diff --git a/read-cache.c b/read-cache.c
index 2c03ec3..35fec46 100644
--- a/read-cache.c
+++ b/read-cache.c@@ -1155,7 +1155,7 @@ int read_index_from(struct index_state *istate, const char *path) size_t mmap_size; errno = EBUSY; - if (istate->alloc) + if (istate->initialized) return istate->cache_nr; errno = ENOENT;
@@ -1195,6 +1195,7 @@ int read_index_from(struct index_state *istate, const char *path) * index size */ istate->alloc = xmalloc(estimate_cache_size(mmap_size, istate->cache_nr)); + istate->initialized = 1; src_offset = sizeof(*hdr); dst_offset = 0;
@@ -1247,6 +1248,7 @@ int discard_index(struct index_state *istate) cache_tree_free(&(istate->cache_tree)); free(istate->alloc); istate->alloc = NULL; + istate->initialized = 0; /* no need to throw away allocated active_cache */ return 0;
diff --git a/unpack-trees.c b/unpack-trees.c
index cba0aca..ef21c62 100644
--- a/unpack-trees.c
+++ b/unpack-trees.c@@ -376,6 +376,7 @@ int unpack_trees(unsigned len, struct tree_desc *t, struct unpack_trees_options state.refresh_cache = 1; memset(&o->result, 0, sizeof(o->result)); + o->result.initialized = 1; if (o->src_index) o->result.timestamp = o->src_index->timestamp; o->merge_size = len;