[PATCH v2 3/7] builtin/receive-pack: read unpack limit config lazily

[Justin Tobler <jltobler@gmail.com>]

In git-receive-pack(1), the `receive.unpackLimit` and
`transfer.unpackLimit` configuration decides whether an incoming
packfile should be exploded into loose objects or kept as a packfile
on-disk. In a subsequent commit, the logic to write the incoming
packfile is made ODB backend agnostic and moved behind a pluggable ODB
transaction interface. Consequently, whether to explode a packfile is a
detail of how a particular backend stores objects and should not be a
part of the generic interface itself.

In preparation for this, instead resolve the unpack limit lazily inside
`unpack()` by reading the configuration directly. The now-unused unpack
limit globals are dropped accordingly.

Signed-off-by: Justin Tobler <jltobler@gmail.com>
---
 builtin/receive-pack.c | 44 ++++++++++++++++++++++++------------------
 1 file changed, 25 insertions(+), 19 deletions(-)

diff --git a/builtin/receive-pack.c b/builtin/receive-pack.c
index 78d2911c00..5264d70467 100644
--- a/builtin/receive-pack.c
+++ b/builtin/receive-pack.c
@@ -62,12 +62,9 @@ static enum deny_action deny_delete_current = DENY_UNCONFIGURED;
 static int receive_fsck_objects = -1;
 static int transfer_fsck_objects = -1;
 static struct strbuf fsck_msg_types = STRBUF_INIT;
-static int receive_unpack_limit = -1;
-static int transfer_unpack_limit = -1;
 static int advertise_atomic_push = 1;
 static int advertise_push_options;
 static int advertise_sid;
-static int unpack_limit = 100;
 static off_t max_input_size;
 static int report_status;
 static int report_status_v2;
@@ -157,16 +154,6 @@ static int receive_pack_config(const char *var, const char *value,
 		return 0;
 	}
 
-	if (strcmp(var, "receive.unpacklimit") == 0) {
-		receive_unpack_limit = git_config_int(var, value, ctx->kvi);
-		return 0;
-	}
-
-	if (strcmp(var, "transfer.unpacklimit") == 0) {
-		transfer_unpack_limit = git_config_int(var, value, ctx->kvi);
-		return 0;
-	}
-
 	if (strcmp(var, "receive.fsck.skiplist") == 0) {
 		char *path;
 
@@ -2333,6 +2320,30 @@ static void push_header_arg(struct strvec *args, struct pack_header *hdr)
 		     ntohl(hdr->hdr_version), ntohl(hdr->hdr_entries));
 }
 
+static int get_unpack_limit(struct repository *repo)
+{
+	static int limit = -1;
+
+	if (limit < 0) {
+		int receive_limit = -1;
+		int transfer_limit = -1;
+
+		repo_config_get_int(repo, "receive.unpacklimit",
+				    &receive_limit);
+		repo_config_get_int(repo, "transfer.unpacklimit",
+				    &transfer_limit);
+
+		if (receive_limit >= 0)
+			limit = receive_limit;
+		else if (transfer_limit >= 0)
+			limit = transfer_limit;
+		else
+			limit = 100;
+	}
+
+	return limit;
+}
+
 static const char *unpack(struct odb_transaction *transaction,
 			  const char *shallow_file, int err_fd)
 {
@@ -2360,7 +2371,7 @@ static const char *unpack(struct odb_transaction *transaction,
 
 	odb_transaction_env(transaction, &child.env);
 
-	if (ntohl(hdr.hdr_entries) < unpack_limit) {
+	if (ntohl(hdr.hdr_entries) < get_unpack_limit(the_repository)) {
 		strvec_push(&child.args, "unpack-objects");
 		push_header_arg(&child.args, &hdr);
 		if (quiet)
@@ -2652,11 +2663,6 @@ int cmd_receive_pack(int argc,
 	if (cert_nonce_seed)
 		push_cert_nonce = prepare_push_cert_nonce(service_dir, time(NULL));
 
-	if (0 <= receive_unpack_limit)
-		unpack_limit = receive_unpack_limit;
-	else if (0 <= transfer_unpack_limit)
-		unpack_limit = transfer_unpack_limit;
-
 	switch (determine_protocol_version_server()) {
 	case protocol_v2:
 		/*
-- 
2.55.0.424.g13c7afec21