Basic dodgy version of a git2 binding

2 files changed, 283 insertions, 2 deletions

diff --git a/Makefile b/Makefile
index 49336d9..0afd01b 100644
--- a/Makefile
+++ b/Makefile
@@ -10,6 +10,16 @@ INST_BASE := $(PREFIX)
 INST_ROOT := $(DESTDIR)$(INST_BASE)/share/lua/$(LUA_VER)
 C_INST_ROOT := $(DESTDIR)$(INST_BASE)/lib/lua/$(LUA_VER)
 
+INCS := -I/usr/include/lua$(LUA_VER) -Ilibgit2/build/gall-install/include
+OPT := -O0 -g
+PIC := -fPIC
+WARN := -Wall -Werror
+DEFS := -D'LUA_INTERP_NAME="$(LUA_INTERP_NAME)"' \
+        -D'LUA_INTERP_PATH="$(LUA_INTERP_PATH)"'
+CFLAGS := $(INCS) $(OPT) $(WARN) $(DEFS) $(PIC) $(CFLAGS)
+LIBGIT2_LDEPS ?= -lssl -lrt
+LFLAGS := -O1 -g -Llibgit2/build/gall-install/lib -lgit2 $(LIBGIT2_LDEPS) $(LFLAGS)
+
 MOD_FILES := $(patsubst %,%.lua,$(subst .,/,$(MODULES)))
 
 install: cmodule
@@ -30,11 +40,14 @@ cmodule: try-cmodule
 try-cmodule:
 	-@$(MAKE) --no-print-directory do-cmodule
 
-do-cmodule: libgit2/build/gall-install-stamp
+do-cmodule: lib/gall/ll/git2.so
+
+lib/gall/ll/git2.so: libgit2/build/gall-install-stamp lib/gall/ll/git2.c
+	$(CC) $(CFLAGS) lib/gall/ll/git2.c -o $@ -shared $(LFLAGS)
 
 libgit2/build/gall-install-stamp:
 	mkdir -p libgit2/build
-	cd libgit2/build && cmake -DBUILD_SHARED_LIBS:BOOLEAN=OFF -DCMAKE_INSTALL_PREFIX:PATH=$(shell pwd)/libgit2/build/gall-install ..
+	cd libgit2/build && cmake -DBUILD_SHARED_LIBS:BOOLEAN=OFF -DCMAKE_INSTALL_PREFIX:PATH=$(shell pwd)/libgit2/build/gall-install -DCMAKE_C_FLAGS=-fPIC ..
 	cd libgit2/build && $(MAKE)
 	echo "DISABLED BECAUSE LIBGIT2 AUTHORS ARE MAD: cd libgit2/build && $(MAKE) test"
 	cd libgit2/build && ./libgit2_clar -xonline
diff --git a/lib/gall/ll/git2.c b/lib/gall/ll/git2.c
new file mode 100644
index 0000000..4eecb91
--- /dev/null
+++ b/lib/gall/ll/git2.c
@@ -0,0 +1,268 @@
+/* git2.c
+ *
+ * Simple binding to the parts of libgit2 in use by Gall.
+ *
+ * Copyright 2014 Daniel Silverstone <dsilvers@digital-scurf.org>
+ */
+
+#include <lua.h>
+#include <lauxlib.h>
+#include "git2.h"
+
+typedef struct {
+	git_repository *repo;
+	git_odb *odb;
+} repo_et_al_t;
+
+static inline git_repository *to_repo(lua_State *L, int idx)
+{
+	repo_et_al_t *real = lua_touserdata(L, idx);
+	if (real == NULL)
+		return NULL;
+	return real->repo;
+}
+
+static inline git_odb *to_odb(lua_State *L, int idx)
+{
+	repo_et_al_t *real = lua_touserdata(L, idx);
+	if (real == NULL)
+		return NULL;
+	return real->odb;
+}
+
+/* Push the most recent error from libgit2 */
+static int push_git2_error(lua_State *L)
+{
+	const git_error *err = giterr_last();
+	lua_pushnil(L);
+	lua_pushstring(L, err->message);
+	return 2;
+}
+
+
+
+static int L_gc_repo(lua_State *L)
+{
+	repo_et_al_t *real = lua_touserdata(L, 1);
+	if (real->odb != NULL)
+		git_odb_free(real->odb);
+	if (real->repo != NULL)
+		git_repository_free(real->repo);
+	real->repo = NULL;
+	real->odb = NULL;
+	return 0;
+}
+
+/* Trivial Repository binding, GC will free the repo */
+static int L_open_repo(lua_State *L)
+{
+	const char *repopath = luaL_checkstring(L, 1);
+	int ret;
+	repo_et_al_t *real = lua_newuserdata(L, sizeof(*real));
+	real->repo = NULL; real->odb = NULL;
+	
+	ret = git_repository_open(&real->repo, repopath);
+	if (ret != 0) {
+		return push_git2_error(L);
+	}
+	
+	ret = git_repository_odb(&real->odb, real->repo);
+	if (ret != 0) {
+		push_git2_error(L);
+		git_repository_free(real->repo);
+		return 2;
+	}
+	
+	lua_pushvalue(L, lua_upvalueindex(1));
+	lua_setmetatable(L, -2);
+	return 1;
+}
+
+static int L_lookup_symbolic_ref(lua_State *L)
+{
+	git_repository *repo = to_repo(L, 1);
+	const char *refname = luaL_checkstring(L, 2);
+	git_reference *ref = NULL;
+	if (git_reference_lookup(&ref, repo, refname) != 0) {
+		return push_git2_error(L);
+	}
+	if (git_reference_type(ref) != GIT_REF_SYMBOLIC) {
+		git_reference_free(ref);
+		lua_pushnil(L);
+		lua_pushfstring(L, "%s is not symbolic", refname);
+		return 2;
+	}
+	lua_pushstring(L, git_reference_symbolic_target(ref));
+	git_reference_free(ref);
+	return 1;
+}
+
+static int format_oid(lua_State *L, git_oid *oid)
+{
+	char oidstr[40];
+	git_oid_fmt(oidstr, oid);
+	lua_pushlstring(L, oidstr, 40);
+	return 1;
+}
+
+static int L_lookup_sha_from_ref(lua_State *L)
+{
+	git_repository *repo = to_repo(L, 1);
+	const char *refname = luaL_checkstring(L, 2);
+	git_oid ref;
+	if (git_reference_name_to_id(&ref, repo, refname) != 0) {
+		return push_git2_error(L);
+	}
+	return format_oid(L, &ref);
+}
+
+static int parse_oid(lua_State *L, int spos, git_oid *oid)
+{
+	const char *oid_s = luaL_checkstring(L, spos);
+	int ret = git_oid_fromstr(oid, oid_s);
+	if (ret != 0)
+		return push_git2_error(L);
+	return 0;
+}
+
+static int L_merge_base(lua_State *L)
+{
+	git_repository *repo = to_repo(L, 1);
+	git_oid left, right, out;
+	int ret;	
+	if (parse_oid(L, 2, &left) != 0)
+		return 2;
+	if (parse_oid(L, 3, &right) != 0)
+		return 2;
+	ret = git_merge_base(&out, repo, &left, &right);
+	if (ret == 0)
+		return format_oid(L, &out);
+	if (ret == GIT_ENOTFOUND) {
+		lua_pushnil(L);
+		lua_pushliteral(L, "ENOTFOUND");
+		return 2;
+	}
+	return push_git2_error(L);
+}
+
+static int L_gc_odb_object(lua_State *L)
+{
+	git_odb_object **obj = lua_touserdata(L, 1);
+	if (*obj != NULL)
+		git_odb_object_free(*obj);
+	*obj = NULL;
+	return 0;
+}
+
+static int L_get_object(lua_State *L)
+{
+	git_odb *odb = to_odb(L, 1);
+	git_odb_object **obj = lua_newuserdata(L, sizeof(*obj));
+	git_oid oid;
+	if (parse_oid(L, 2, &oid) != 0)
+		return 2;
+	if (git_odb_read(obj, odb, &oid) != 0)
+		return push_git2_error(L);
+	lua_pushvalue(L, lua_upvalueindex(1));
+	lua_setmetatable(L, -2);
+	return 1;
+}
+
+static int L_get_object_size(lua_State *L)
+{
+	git_odb_object **obj = lua_touserdata(L, 1);
+	lua_pushnumber(L, git_odb_object_size(*obj));
+	return 1;
+}
+
+static void push_object_type_str(lua_State *L, git_otype ty)
+{
+	switch(ty) {
+	case GIT_OBJ_ANY:
+		lua_pushliteral(L, "any");
+		break;
+	case GIT_OBJ_BAD:
+		lua_pushliteral(L, "bad");
+		break;
+	case GIT_OBJ__EXT1:
+		lua_pushliteral(L, "reserved");
+		break;
+	case GIT_OBJ_COMMIT:
+		lua_pushliteral(L, "commit");
+		break;
+	case GIT_OBJ_TREE:
+		lua_pushliteral(L, "tree");
+		break;
+	case GIT_OBJ_BLOB:
+		lua_pushliteral(L, "blob");
+		break;
+	case GIT_OBJ_TAG:
+		lua_pushliteral(L, "tag");
+		break;
+	case GIT_OBJ__EXT2:
+		lua_pushliteral(L, "reserved");
+		break;
+	case GIT_OBJ_OFS_DELTA:
+		lua_pushliteral(L, "delta");
+		break;
+	case GIT_OBJ_REF_DELTA:
+		lua_pushliteral(L, "refdelta");
+		break;
+	default:
+		lua_pushliteral(L, "unknown");
+		break;
+	}
+}
+
+static int L_get_object_type(lua_State *L)
+{
+	git_odb_object **obj = lua_touserdata(L, 1);
+	push_object_type_str(L, git_odb_object_type(*obj));
+	return 1;
+}
+
+static int L_get_object_raw(lua_State *L)
+{
+	git_odb_object **obj = lua_touserdata(L, 1);
+	lua_pushlstring(L, git_odb_object_data(*obj),
+			git_odb_object_size(*obj));
+	return 1;
+}
+
+int luaopen_git2(lua_State *L)
+{
+	lua_newtable(L);
+	lua_pushliteral(L, "LIBGIT2_VERSION");
+	lua_pushliteral(L, LIBGIT2_VERSION);
+	lua_settable(L, -3);
+	
+	lua_pushliteral(L, "open_repo");
+	lua_newtable(L);
+	lua_pushliteral(L, "__gc");
+	lua_pushcclosure(L, L_gc_repo, 0);
+	lua_settable(L, -3);
+	lua_pushcclosure(L, L_open_repo, 1);
+	lua_settable(L, -3);
+
+	lua_pushliteral(L, "get_object");
+	lua_newtable(L);
+	lua_pushliteral(L, "__gc");
+	lua_pushcclosure(L, L_gc_odb_object, 0);
+	lua_settable(L, -3);
+	lua_pushcclosure(L, L_get_object, 1);
+	lua_settable(L, -3);
+
+#define BASIC_FUNC(FN)				\
+	do {					\
+		lua_pushliteral(L, #FN);	\
+		lua_pushcclosure(L, L_##FN, 0);	\
+		lua_settable(L, -3);		\
+	} while (0)
+	BASIC_FUNC(lookup_symbolic_ref);
+	BASIC_FUNC(lookup_sha_from_ref);
+	BASIC_FUNC(merge_base);
+	BASIC_FUNC(get_object_size);
+	BASIC_FUNC(get_object_type);
+	BASIC_FUNC(get_object_raw);
+	return 1;
+}