Bind repository discovery

c_src/geef.c

@@ -84,6 +84,7 @@ static ErlNifFunc geef_funcs[] =
 {
 	{"repository_init", 2, geef_repository_init},
 	{"repository_open", 1, geef_repository_open},
+	{"repository_discover", 1, geef_repository_discover},
 	{"repository_is_bare", 1, geef_repository_is_bare},
 	{"repository_get_path", 1, geef_repository_path},
 	{"repository_get_workdir", 1, geef_repository_workdir},

c_src/repository.c

@@ -87,6 +87,62 @@ geef_repository_open(ErlNifEnv *env, int argc, const ERL_NIF_TERM argv[])
 	return enif_make_tuple2(env, atoms.ok, term_repo);
 }
 
+ERL_NIF_TERM
+geef_repository_discover(ErlNifEnv *env, int argc, const ERL_NIF_TERM argv[])
+{
+	char *path, *buffer;
+	size_t buffer_len;
+	ErlNifBinary bin, res_bin;
+	int error;
+
+	if (!enif_inspect_iolist_as_binary(env, argv[0], &bin))
+		return enif_make_badarg(env);
+
+	path = malloc(bin.size + 1);
+	if (!path)
+		return atoms.error;
+
+	memcpy(path, bin.data, bin.size);
+	path[bin.size] = '\0';
+
+	buffer_len = 256;
+	buffer = malloc(buffer_len);
+	if (!buffer)
+		return atoms.error;
+
+	while ((error = git_repository_discover(buffer, buffer_len, path, 0, NULL)) < 0 &&
+	       giterr_last()->klass == GITERR_REPOSITORY) {
+		char *tmp;
+		buffer_len *= 2;
+		tmp = realloc(buffer, buffer_len);
+		if (!tmp) {
+			free(path);
+			free(buffer);
+			return atoms.error;
+		}
+
+		buffer = tmp;
+	}
+
+	free(path);
+
+	if (error < 0) {
+		free(buffer);
+		return geef_error(env);
+	}
+
+	buffer_len = strlen(buffer);
+	if (!enif_alloc_binary(buffer_len, &res_bin)) {
+		free(buffer);
+		return atoms.error;
+	}
+
+	memcpy(res_bin.data, buffer, buffer_len);
+	free(buffer);
+
+	return enif_make_tuple2(env, atoms.ok, enif_make_binary(env, &res_bin));
+}
+
 ERL_NIF_TERM
 geef_repository_path(ErlNifEnv *env, int argc, const ERL_NIF_TERM argv[])
 {

c_src/repository.h

@@ -8,6 +8,7 @@
 
 ERL_NIF_TERM geef_repository_init(ErlNifEnv *env, int argc, const ERL_NIF_TERM argv[]);
 ERL_NIF_TERM geef_repository_open(ErlNifEnv *env, int argc, const ERL_NIF_TERM argv[]);
+ERL_NIF_TERM geef_repository_discover(ErlNifEnv *env, int argc, const ERL_NIF_TERM argv[]);
 ERL_NIF_TERM geef_repository_path(ErlNifEnv *env, int argc, const ERL_NIF_TERM argv[]);
 ERL_NIF_TERM geef_repository_workdir(ErlNifEnv *env, int argc, const ERL_NIF_TERM argv[]);
 ERL_NIF_TERM geef_repository_is_bare(ErlNifEnv *env, int argc, const ERL_NIF_TERM argv[]);

src/geef.erl

@@ -5,7 +5,7 @@
 
 % repository operations
 -export([repository_get_path/1, repository_get_odb/1, repository_open/1, repository_init/2,
-	 repository_is_bare/1, repository_get_workdir/1]).
+	 repository_is_bare/1, repository_get_workdir/1, repository_discover/1]).
 
 % oid parsing
 -export([oid_fmt/1, oid_parse/1]).
@@ -41,6 +41,10 @@ repository_get_odb(_Val) ->
 repository_init(_Path, _Bare) ->
     nif_error(?LINE).
 
+-spec repository_discover(iolist()) -> {ok, string()} | error.
+repository_discover(_Path) ->
+    nif_error(?LINE).
+
 reference_list(_Repo) ->
     nif_error(?LINE).
 

src/geef_repo.erl

@@ -1,6 +1,6 @@
 -module(geef_repo).
 
--export([open/1, init/2, path/1, workdir/1, odb/1, is_bare/1, references/1]).
+-export([open/1, init/2, path/1, workdir/1, odb/1, is_bare/1, references/1, discover/1]).
 
 -include("geef_records.hrl").
 
@@ -29,6 +29,10 @@ is_bare(#repo{handle=Handle}) ->
 references(#repo{handle=Handle}) ->
     geef:reference_list(Handle).
 
+-spec discover(iolist()) -> {ok, binary()} | error | {error, term()}.
+discover(Path) ->
+    geef:repository_discover(Path).
+
 -spec open(iolist()) -> {ok, repo()} | {error, term()}.
 open(Path) ->
     case geef:repository_open(Path) of