easy: add a function to list directory paths

This change adds `sqsh_easy_directory_list_path()`, a function to list
the contents of a directory as a list of file paths. This enables the
user to get a list of paths that can be directly passed to other easy
functions like `sqsh_easy_file_content()`.

This change also adds a test for the new function.

include/sqsh_easy.h

@@ -119,7 +119,7 @@ sqsh_easy_file_mtime(struct SqshArchive *archive, const char *path, int *err);
  */
 
 /**
- * @brief retrieves the contents of a directory.
+ * @brief retrieves the contents of a directory as a list of file names
  *
  * The returned list needs to be released with `free()`.
  *
@@ -132,6 +132,20 @@ sqsh_easy_file_mtime(struct SqshArchive *archive, const char *path, int *err);
 char **sqsh_easy_directory_list(
 		struct SqshArchive *archive, const char *path, int *err);
 
+/**
+ * @brief retrieves the contents of a directory as a list of file paths
+ *
+ * The returned list needs to be released with `free()`.
+ *
+ * @param[in] archive  The sqsh archive context.
+ * @param[in] path     The path the file or directory.
+ * @param[out] err     Pointer to an int where the error code will be stored.
+ *
+ * @return A list of files and directories on success, NULL on error.
+ */
+char **sqsh_easy_directory_list_path(
+		struct SqshArchive *archive, const char *path, int *err);
+
 /***************************************
  * easy/xattr.c
  */

libsqsh/src/easy/directory.c

@@ -31,7 +31,6 @@
  * @file         file.c
  */
 
-#include <stdint.h>
 #define _DEFAULT_SOURCE
 
 #include <sqsh_easy.h>
@@ -46,6 +45,88 @@
 #include <sqsh_file_private.h>
 #include <sqsh_tree_private.h>
 
+struct DirectoryIterator {
+	struct SqshDirectoryIterator dir;
+	const char *path;
+	size_t path_size;
+	struct CxBuffer value;
+};
+
+static int
+directory_path_collector_next(
+		void *iterator, const char **value, size_t *size) {
+	struct DirectoryIterator *it = iterator;
+	int rv = 0;
+	if (sqsh_directory_iterator_next(&it->dir, &rv)) {
+		cx_buffer_drain(&it->value);
+		rv = cx_buffer_append(
+				&it->value, (const uint8_t *)it->path, it->path_size);
+		if (rv < 0) {
+			goto out;
+		}
+		rv = cx_buffer_append(&it->value, (const uint8_t *)"/", 1);
+		if (rv < 0) {
+			goto out;
+		}
+		rv = cx_buffer_append(
+				&it->value,
+				(const uint8_t *)sqsh_directory_iterator_name(&it->dir),
+				(size_t)sqsh_directory_iterator_name_size(&it->dir));
+		if (rv < 0) {
+			goto out;
+		}
+		*value = (const char *)cx_buffer_data(&it->value);
+		*size = cx_buffer_size(&it->value);
+	}
+out:
+	return rv;
+}
+
+char **
+sqsh_easy_directory_list_path(
+		struct SqshArchive *archive, const char *path, int *err) {
+	int rv = 0;
+	struct SqshFile *file = NULL;
+	struct DirectoryIterator iterator = {0};
+	char **list = NULL;
+
+	file = sqsh_open(archive, path, &rv);
+	if (rv < 0) {
+		goto out;
+	}
+
+	rv = sqsh__directory_iterator_init(&iterator.dir, file);
+	if (rv < 0) {
+		goto out;
+	}
+
+	rv = cx_buffer_init(&iterator.value);
+	if (rv < 0) {
+		goto out;
+	}
+
+	iterator.path = path;
+	iterator.path_size = strlen(path);
+	while (iterator.path_size > 0 &&
+		   iterator.path[iterator.path_size - 1] == '/') {
+		iterator.path_size--;
+	}
+
+	rv = cx_collect(&list, directory_path_collector_next, &iterator.dir);
+	if (rv < 0) {
+		goto out;
+	}
+
+out:
+	cx_buffer_cleanup(&iterator.value);
+	sqsh__directory_iterator_cleanup(&iterator.dir);
+	sqsh_close(file);
+	if (err) {
+		*err = rv;
+	}
+	return list;
+}
+
 static int
 directory_collector_next(void *iterator, const char **value, size_t *size) {
 	int rv = 0;

test/libsqsh/easy/directory.c

@@ -80,6 +80,48 @@ list_two_files(void) {
 	sqsh__archive_cleanup(&archive);
 }
 
+static void
+list_two_paths(void) {
+	int rv = 0;
+	struct SqshArchive archive = {0};
+	uint8_t payload[] = {
+			/* clang-format off */
+			SQSH_HEADER,
+			/* inode */
+			[INODE_TABLE_OFFSET] = METABLOCK_HEADER(0, 1024),
+			INODE_HEADER(1, 0, 0, 0, 0, 1),
+			INODE_BASIC_DIR(0, 33, 0, 0),
+			[INODE_TABLE_OFFSET+2+128] = 
+			INODE_HEADER(3, 0, 0, 0, 0, 2),
+			INODE_BASIC_SYMLINK(3),
+			't', 'g', 't',
+			[INODE_TABLE_OFFSET+2+256] =
+			INODE_HEADER(2, 0, 0, 0, 0, 3),
+			INODE_BASIC_FILE(0, 0xFFFFFFFF, 0, 0),
+			[DIRECTORY_TABLE_OFFSET] = METABLOCK_HEADER(0, 128),
+			DIRECTORY_HEADER(2, 0, 0),
+			DIRECTORY_ENTRY(128, 2, 3, 1),
+			'1',
+			DIRECTORY_ENTRY(256, 3, 2, 1),
+			'2',
+			[FRAGMENT_TABLE_OFFSET] = 0,
+			/* clang-format on */
+	};
+	mk_stub(&archive, payload, sizeof(payload));
+
+	char **dir_list = sqsh_easy_directory_list_path(&archive, "/", &rv);
+	assert(rv == 0);
+	assert(dir_list != NULL);
+
+	assert(strcmp(dir_list[0], "/1") == 0);
+	assert(strcmp(dir_list[1], "/2") == 0);
+	assert(dir_list[2] == NULL);
+
+	free(dir_list);
+	sqsh__archive_cleanup(&archive);
+}
+
 DECLARE_TESTS
 TEST(list_two_files)
+TEST(list_two_paths)
 END_TESTS