environment: move access to "core.bigFileThreshold" into repo settings

The "core.bigFileThreshold" setting is stored in a global variable and
populated via `git_default_core_config()`. This may cause issues in
the case where one is handling multiple different repositories in a
single process with different values for that config key, as we may or
may not see the correct value in that case. Furthermore, global state
blocks our path towards libification.

Refactor the code so that we instead store the value in `struct
repo_settings`, where the value is computed as-needed and cached.

Note that this change requires us to adapt one test in t1050 that
verifies that we die when parsing an invalid "core.bigFileThreshold"
value. The exercised Git command doesn't use the value at all, and thus
it won't hit the new code path that parses the value. This is addressed
by using git-hash-object(1) instead, which does read the value.

Signed-off-by: Patrick Steinhardt <ps@pks.im>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

4 files changed, 12 insertions, 7 deletions

diff --git a/builtin/fast-import.c b/builtin/fast-import.c
index e1758aa951..ce52f78579 100644
--- a/builtin/fast-import.c
+++ b/builtin/fast-import.c
@@ -2021,7 +2021,7 @@ static void parse_and_store_blob(
 	static struct strbuf buf = STRBUF_INIT;
 	uintmax_t len;
 
-	if (parse_data(&buf, big_file_threshold, &len))
+	if (parse_data(&buf, repo_settings_get_big_file_threshold(the_repository), &len))
 		store_object(OBJ_BLOB, &buf, last, oidout, mark);
 	else {
 		if (last) {
@@ -3402,7 +3402,7 @@ static int parse_one_option(const char *option)
 		unsigned long v;
 		if (!git_parse_ulong(option, &v))
 			return 0;
-		big_file_threshold = v;
+		repo_settings_set_big_file_threshold(the_repository, v);
 	} else if (skip_prefix(option, "depth=", &option)) {
 		option_depth(option);
 	} else if (skip_prefix(option, "active-branches=", &option)) {
diff --git a/builtin/index-pack.c b/builtin/index-pack.c
index 174e03afa6..09c0a8adf6 100644
--- a/builtin/index-pack.c
+++ b/builtin/index-pack.c
@@ -485,7 +485,8 @@ static void *unpack_entry_data(off_t offset, unsigned long size,
 		git_hash_update(&c, hdr, hdrlen);
 	} else
 		oid = NULL;
-	if (type == OBJ_BLOB && size > big_file_threshold)
+	if (type == OBJ_BLOB &&
+	    size > repo_settings_get_big_file_threshold(the_repository))
 		buf = fixed_buf;
 	else
 		buf = xmallocz(size);
@@ -799,7 +800,8 @@ static int check_collison(struct object_entry *entry)
 	enum object_type type;
 	unsigned long size;
 
-	if (entry->size <= big_file_threshold || entry->type != OBJ_BLOB)
+	if (entry->size <= repo_settings_get_big_file_threshold(the_repository) ||
+	    entry->type != OBJ_BLOB)
 		return -1;
 
 	memset(&data, 0, sizeof(data));
diff --git a/builtin/pack-objects.c b/builtin/pack-objects.c
index e05dfc4021..eefc6c7809 100644
--- a/builtin/pack-objects.c
+++ b/builtin/pack-objects.c
@@ -499,7 +499,8 @@ static unsigned long write_no_reuse_object(struct hashfile *f, struct object_ent
 
 	if (!usable_delta) {
 		if (oe_type(entry) == OBJ_BLOB &&
-		    oe_size_greater_than(&to_pack, entry, big_file_threshold) &&
+		    oe_size_greater_than(&to_pack, entry,
+					 repo_settings_get_big_file_threshold(the_repository)) &&
 		    (st = open_istream(the_repository, &entry->idx.oid, &type,
 				       &size, NULL)) != NULL)
 			buf = NULL;
@@ -2454,7 +2455,8 @@ static void get_object_details(void)
 		struct object_entry *entry = sorted_by_offset[i];
 		check_object(entry, i);
 		if (entry->type_valid &&
-		    oe_size_greater_than(&to_pack, entry, big_file_threshold))
+		    oe_size_greater_than(&to_pack, entry,
+					 repo_settings_get_big_file_threshold(the_repository)))
 			entry->no_try_delta = 1;
 		display_progress(progress_state, i + 1);
 	}
diff --git a/builtin/unpack-objects.c b/builtin/unpack-objects.c
index 8383bcf404..e20c120913 100644
--- a/builtin/unpack-objects.c
+++ b/builtin/unpack-objects.c
@@ -553,7 +553,8 @@ static void unpack_one(unsigned nr)
 
 	switch (type) {
 	case OBJ_BLOB:
-		if (!dry_run && size > big_file_threshold) {
+		if (!dry_run &&
+		    size > repo_settings_get_big_file_threshold(the_repository)) {
 			stream_blob(size, nr);
 			return;
 		}