From 4c9b429eaa5b3224103fdac171a0624f16f072e9 Mon Sep 17 00:00:00 2001
From: GreekStapler <dvmap@protonmail.com>
Date: Tue, 31 Jan 2023 21:08:09 +0000
Subject: [PATCH] refactor: Package archive parser now returns meaningful error
 enums in case of failure.

---
 include/vieter_package.h     | 12 ++++++++++--
 src/package/vieter_package.c | 11 ++++++-----
 test/package/test_package.c  | 11 ++++++-----
 3 files changed, 22 insertions(+), 12 deletions(-)

diff --git a/include/vieter_package.h b/include/vieter_package.h
index 32fb0eb..c9a941e 100644
--- a/include/vieter_package.h
+++ b/include/vieter_package.h
@@ -3,13 +3,21 @@
 
 typedef struct vieter_package vieter_package;
 
+typedef enum vieter_package_error {
+	vieter_package_ok = 0,
+	vieter_package_unarchive_error = 1,
+	vieter_package_stat_error = 2
+} vieter_package_error;
 
+/*
+ * Allocate an empty package
+ */
+vieter_package *vieter_package_init();
 
 /*
  * Parse package file into something usable by libvieter.
- * The pointer returned by this function will need to freed at a later point.
  */
-vieter_package *vieter_package_read_archive(const char *pkg_path);
+vieter_package_error vieter_package_read_archive(vieter_package *pkg, const char *pkg_path);
 
 /*
  * Deallocate a package.
diff --git a/src/package/vieter_package.c b/src/package/vieter_package.c
index 031fe15..cf273d8 100644
--- a/src/package/vieter_package.c
+++ b/src/package/vieter_package.c
@@ -40,7 +40,7 @@ vieter_package *vieter_package_init() {
 	return calloc(sizeof(vieter_package_info), 1);
 }
 
-vieter_package *vieter_package_read_archive(const char *pkg_path) {
+vieter_package_error vieter_package_read_archive(vieter_package *pkg, const char *pkg_path) {
 	struct archive *a = archive_read_new();
 	struct archive_entry *entry = archive_entry_new();
 
@@ -57,7 +57,7 @@ vieter_package *vieter_package_read_archive(const char *pkg_path) {
 
 	// Exit early if we weren't able to successfully open the archive for reading
 	if (r != ARCHIVE_OK) {
-		return NULL;
+		return vieter_package_unarchive_error;
 	}
 
 	int compression_code = archive_filter_code(a, 0);
@@ -103,7 +103,9 @@ vieter_package *vieter_package_read_archive(const char *pkg_path) {
 	struct stat stats;
 
 	if (stat(pkg_path, &stats) != 0) {
-		return NULL;
+		// errno is set if stat() fails; the calling function should check
+		// the value of errno in case vieter_package_stat_error is returned
+		return vieter_package_stat_error;
 	}
 
 	pkg_info->csize = stats.st_size;
@@ -111,13 +113,12 @@ vieter_package *vieter_package_read_archive(const char *pkg_path) {
 	archive_read_free(a);
 
 	// Create final return value
-	vieter_package *pkg = vieter_package_init();
 	pkg->path = strdup(pkg_path);
 	pkg->info = pkg_info;
 	pkg->files = files;
 	pkg->compression = compression_code;
 
-	return pkg;
+	return vieter_package_ok;
 }
 
 void vieter_package_sha256sum(vieter_package *pkg, char *res) {
diff --git a/test/package/test_package.c b/test/package/test_package.c
index 5bbda26..3c8b249 100644
--- a/test/package/test_package.c
+++ b/test/package/test_package.c
@@ -39,8 +39,9 @@ void test_info_parse() {
 }
 
 void test_pkg_read_archive_files() {
-	vieter_package *pkg = vieter_package_read_archive("./test/package/xcursor-dmz-0.4.5-2-any.pkg.tar.zst");
-	TEST_ASSERT_(pkg != NULL, "failure parsing pkg archive");
+	vieter_package *pkg = vieter_package_init();
+	vieter_package_error e = vieter_package_read_archive(pkg, "./test/package/xcursor-dmz-0.4.5-2-any.pkg.tar.zst");
+	TEST_ASSERT_(e == vieter_package_ok, "failure parsing pkg archive");
 
 	FILE *f = fopen("./test/package/files", "r");
 	TEST_ASSERT_(f != NULL, "could not find test files file in ./test/package");
@@ -58,12 +59,12 @@ void test_pkg_read_archive_files() {
 	TEST_CHECK(pkg->compression = 14);
 
 	vieter_package_free(&pkg);
-
 }
 
 void test_pkg_read_archive_desc() {
-	vieter_package *pkg = vieter_package_read_archive("./test/package/xcursor-dmz-0.4.5-2-any.pkg.tar.zst");
-	TEST_ASSERT_(pkg != NULL, "failure parsing pkg archive");
+	vieter_package *pkg = vieter_package_init();
+	vieter_package_error e = vieter_package_read_archive(pkg, "./test/package/xcursor-dmz-0.4.5-2-any.pkg.tar.zst");
+	TEST_ASSERT_(e == vieter_package_ok, "failure parsing pkg archive");
 
 	char *description = vieter_package_to_description(pkg);