[PATCH v5 26/40] odb-helper: add 'script_mode' to 'struct odb_helper'

[Christian Couder <christian.couder@gmail.com>]

to prepare for having a long running odb helper sub-process
handling the communication between Git and an external odb.

We introduce "odb.<name>.subprocesscommand" to make it
possible to define such a sub-process, and we mark such odb
helpers with the new 'script_mode' field set to 0.

Helpers defined using the existing "odb.<name>.scriptcommand"
are marked with the 'script_mode' field set to 1.

Implementation of the different capabilities/instructions in
the new (sub-)process mode is left for following commits.

Signed-off-by: Christian Couder <chriscool@tuxfamily.org>
---
 external-odb.c |  8 +++++++-
 odb-helper.c   | 19 ++++++++++++++-----
 odb-helper.h   |  1 +
 3 files changed, 22 insertions(+), 6 deletions(-)

diff --git a/external-odb.c b/external-odb.c
index 31d21bfe04..ccca67eff5 100644
--- a/external-odb.c
+++ b/external-odb.c
@@ -32,8 +32,14 @@ static int external_odb_config(const char *var, const char *value, void *data)
 
 	o = find_or_create_helper(name, namelen);
 
-	if (!strcmp(subkey, "scriptcommand"))
+	if (!strcmp(subkey, "scriptcommand")) {
+		o->script_mode = 1;
 		return git_config_string(&o->cmd, var, value);
+	}
+	if (!strcmp(subkey, "subprocesscommand")) {
+		o->script_mode = 0;
+		return git_config_string(&o->cmd, var, value);
+	}
 
 	return 0;
 }
diff --git a/odb-helper.c b/odb-helper.c
index b1f5464214..4c16dd297a 100644
--- a/odb-helper.c
+++ b/odb-helper.c
@@ -123,6 +123,9 @@ int odb_helper_init(struct odb_helper *o)
 	FILE *fh;
 	struct strbuf line = STRBUF_INIT;
 
+	if (!o->script_mode)
+		return 0;
+
 	if (odb_helper_start(o, &cmd, 0, "init") < 0)
 		return -1;
 
@@ -173,16 +176,12 @@ static int odb_helper_object_cmp(const void *va, const void *vb)
 	return hashcmp(a->sha1, b->sha1);
 }
 
-static void odb_helper_load_have(struct odb_helper *o)
+static void have_object_script(struct odb_helper *o)
 {
 	struct odb_helper_cmd cmd;
 	FILE *fh;
 	struct strbuf line = STRBUF_INIT;
 
-	if (o->have_valid)
-		return;
-	o->have_valid = 1;
-
 	if (odb_helper_start(o, &cmd, 0, "have") < 0)
 		return;
 
@@ -194,6 +193,16 @@ static void odb_helper_load_have(struct odb_helper *o)
 	strbuf_release(&line);
 	fclose(fh);
 	odb_helper_finish(o, &cmd);
+}
+
+static void odb_helper_load_have(struct odb_helper *o)
+{
+	if (o->have_valid)
+		return;
+	o->have_valid = 1;
+
+	if (o->script_mode)
+		have_object_script(o);
 
 	qsort(o->have, o->have_nr, sizeof(*o->have), odb_helper_object_cmp);
 }
diff --git a/odb-helper.h b/odb-helper.h
index f2fd2b7c9c..04b85f1d02 100644
--- a/odb-helper.h
+++ b/odb-helper.h
@@ -15,6 +15,7 @@ struct odb_helper {
 	const char *name;
 	const char *cmd;
 	unsigned int supported_capabilities;
+	int script_mode;
 
 	struct odb_helper_object {
 		unsigned char sha1[20];
-- 
2.14.0.rc1.52.gf02fb0ddac.dirty