[PATCH 1/2] Resumable clone: create git-prime-clone (Draft)

[Kevin Wern <kevin.m.wern@gmail.com>]

Create a bare-bones version of git-prime-clone, which returns the
location of an alternate resource specified by the server that the
client should fetch and build before returning to perform an incremental
fetch.

At this point, no validation is performed of the file's existence, the
file's validity as a fully connected archive, or its correspondence
to the specified resource type in .git/config.
---
 Makefile      |  1 +
 prime-clone.c | 87 +++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
 2 files changed, 88 insertions(+)
 create mode 100644 prime-clone.c

diff --git a/Makefile b/Makefile
index 3f03366..34febdc 100644
--- a/Makefile
+++ b/Makefile
@@ -579,6 +579,7 @@ PROGRAM_OBJS += sh-i18n--envsubst.o
 PROGRAM_OBJS += shell.o
 PROGRAM_OBJS += show-index.o
 PROGRAM_OBJS += upload-pack.o
+PROGRAM_OBJS += prime-clone.o
 PROGRAM_OBJS += remote-testsvn.o
 
 # Binary suffix, set to .exe for Windows builds
diff --git a/prime-clone.c b/prime-clone.c
new file mode 100644
index 0000000..74fd8d4
--- /dev/null
+++ b/prime-clone.c
@@ -0,0 +1,87 @@
+#include "cache.h"
+#include "refs.h"
+
+#define PRIME_CLONE_ENABLED 1
+
+static const char prime_clone_usage[] = "git prime-clone [--strict] <dir>";
+
+static unsigned int enabled;
+static const char *url = "\0";
+static const char *filetype = "\0";
+
+static void prime_clone(void)
+{
+	if (enabled)
+	{
+		if (strlen(url) != 0 && strlen(filetype) != 0) {
+			packet_write(1, "url %s\n", url);
+			packet_write(1, "filetype %s\n", filetype);
+		}
+		else {
+			packet_write(1, "prime-clone not properly configured\n");
+		}
+	}
+	else {
+		packet_write(1, "prime-clone not enabled\n");
+	}
+	packet_flush(1);
+}
+
+static int prime_clone_config(const char *var, const char *value, void *unused)
+{
+	if (!strcmp("primeclone.url",var)) {
+		return git_config_pathname(&url, var, value);
+	}
+	if (!strcmp("primeclone.enabled",var)) {
+		if (git_config_bool(var, value))
+			enabled = PRIME_CLONE_ENABLED;
+		else
+			enabled = ~PRIME_CLONE_ENABLED;
+	}
+	if (!strcmp("primeclone.filetype",var)) {
+		return git_config_string(&filetype, var, value);
+	}
+	return parse_hide_refs_config(var, value, "primeclone");
+}
+
+int main(int argc, char **argv)
+{
+	char *dir;
+	int i;
+	int strict = 0;
+
+	git_setup_gettext();
+
+	packet_trace_identity("prime-clone");
+	git_extract_argv0_path(argv[0]);
+	check_replace_refs = 0;
+
+	for (i = 1; i < argc; i++) {
+		char *arg = argv[i];
+
+		if (arg[0] != '-')
+			break;
+		if (!strcmp(arg, "--strict")) {
+			strict = 1;
+			continue;
+		}
+		if (!strcmp(arg, "--")) {
+			i++;
+			break;
+		}
+	}
+
+	if (i != argc-1)
+		usage(prime_clone_usage);
+
+	setup_path();
+
+	dir = argv[i];
+
+	if (!enter_repo(dir, strict))
+		die("'%s' does not appear to be a git repository", dir);
+
+	git_config(prime_clone_config, NULL);
+	prime_clone();
+	return 0;
+}
-- 
1.9.1