restore session

1 files changed, 173 insertions, 0 deletions

diff --git a/session.c b/session.c
new file mode 100644
index 0000000..cbd84b0
--- /dev/null
+++ b/session.c
@@ -0,0 +1,173 @@
+#define SESSION_FILENAME "session.txt"
+#define SESSION_VERSION "\x7fTED0001"
+
+static void session_write_node(Ted *ted, FILE *fp, u16 node_idx) {
+	Node *node = &ted->nodes[node_idx];
+	write_u16(fp, node_idx);
+	bool is_split = !node->tabs;
+	write_bool(fp, is_split);
+	if (is_split) {
+		write_float(fp, node->split_pos);
+		write_bool(fp, node->split_vertical);
+		write_u16(fp, node->split_a);
+		write_u16(fp, node->split_b);
+	} else {
+		write_u16(fp, node->active_tab); // active tab
+		write_u16(fp, (u16)arr_len(node->tabs)); // ntabs
+		arr_foreach_ptr(node->tabs, u16, tab) {
+			write_u16(fp, *tab);
+		}
+	}
+}
+
+static void session_read_node(Ted *ted, FILE *fp) {
+	u16 node_idx = read_u16(fp);
+	if (node_idx >= TED_MAX_NODES) {
+		debug_println("WARNING: Invalid node index (see %s:%d)!\n", __FILE__, __LINE__);
+		return;
+	}
+	ted->nodes_used[node_idx] = true;
+	Node *node = &ted->nodes[node_idx];
+	bool is_split = read_bool(fp);
+	if (is_split) {
+		node->split_pos = clampf(read_float(fp), 0, 1);
+		node->split_vertical = read_bool(fp);
+		node->split_a = clamp_u16(read_u16(fp), 0, TED_MAX_NODES);
+		node->split_b = clamp_u16(read_u16(fp), 0, TED_MAX_NODES);
+	} else {
+		node->active_tab = read_u16(fp);
+		u16 ntabs = clamp_u16(read_u16(fp), 0, TED_MAX_TABS);
+		for (u16 i = 0; i < ntabs; ++i) {
+			u16 buf_idx = read_u16(fp);
+			if (buf_idx >= TED_MAX_BUFFERS) continue;
+			arr_add(node->tabs, buf_idx);
+		}
+	}
+}
+
+static void session_write_buffer(Ted *ted, FILE *fp, u16 buffer_idx) {
+	write_u16(fp, buffer_idx);
+	TextBuffer *buffer = &ted->buffers[buffer_idx];
+	// some info about the buffer that should be restored
+	if (buffer->filename && !buffer_is_untitled(buffer))
+		write_cstr(fp, buffer->filename);
+	else
+		write_char(fp, 0);
+	write_double(fp, buffer->scroll_x);
+	write_double(fp, buffer->scroll_y);
+	write_bool(fp, buffer->view_only);
+	buffer_pos_write(buffer->cursor_pos, fp);
+	write_bool(fp, buffer->selection);
+	if (buffer->selection)
+		buffer_pos_write(buffer->selection_pos, fp);
+}
+
+static void session_read_buffer(Ted *ted, FILE *fp) {
+	u16 buffer_idx = read_u16(fp);
+	if (buffer_idx >= TED_MAX_BUFFERS) {
+		debug_println("WARNING: Invalid buffer index (see %s:%d)!\n", __FILE__, __LINE__);
+		return;
+	}
+	TextBuffer *buffer = &ted->buffers[buffer_idx];
+	ted->buffers_used[buffer_idx] = true;
+	char filename[TED_PATH_MAX] = {0};
+	read_cstr(fp, filename, sizeof filename);
+	buffer_create(buffer, ted);
+	if (!buffer_haserr(buffer)) {
+		if (*filename) {
+			if (!buffer_load_file(buffer, filename))
+				buffer_new_file(buffer, TED_UNTITLED);
+		} else {
+			buffer_new_file(buffer, TED_UNTITLED);
+		}
+		buffer->scroll_x = read_double(fp);
+		buffer->scroll_y = read_double(fp);
+		buffer->view_only = read_bool(fp);
+		buffer->cursor_pos = buffer_pos_read(buffer, fp);
+		buffer->selection = read_bool(fp);
+		if (buffer->selection)
+			buffer->selection_pos = buffer_pos_read(buffer, fp);
+	}
+}
+
+static void session_write_file(Ted *ted, FILE *fp) {
+	fwrite(SESSION_VERSION, 1, sizeof SESSION_VERSION, fp);
+
+	write_u16(fp, (u16)(ted->active_node - ted->nodes)); // active node idx
+	write_u16(fp, (u16)(ted->active_buffer - ted->buffers)); // active buffer idx
+
+	u16 nnodes = 0;
+	for (u16 i = 0; i < TED_MAX_NODES; ++i)
+		nnodes += ted->nodes_used[i];
+	write_u16(fp, nnodes);
+	for (u16 i = 0; i < TED_MAX_NODES; ++i)
+		if (ted->nodes_used[i])
+			session_write_node(ted, fp, i);
+
+	u16 nbuffers = 0;
+	for (u16 i = 0; i < TED_MAX_BUFFERS; ++i)
+		nbuffers += ted->buffers_used[i];
+	write_u16(fp, nbuffers);
+	for (u16 i = 0; i < TED_MAX_BUFFERS; ++i)
+		if (ted->buffers_used[i])
+			session_write_buffer(ted, fp, i);
+}
+
+static void session_read_file(Ted *ted, FILE *fp) {
+	char version[sizeof SESSION_VERSION] = {0};
+	fread(version, 1, sizeof version, fp);
+	if (memcmp(version, SESSION_VERSION, sizeof version) != 0) {
+		debug_println("WARNING: Session file has wrong version (see %s:%d)!\n", __FILE__, __LINE__);
+		return; // wrong version
+	}
+
+	u16 active_node_idx = clamp_u16(read_u16(fp), 0, TED_MAX_NODES);
+	u16 active_buffer_idx = clamp_u16(read_u16(fp), 0, TED_MAX_BUFFERS);
+
+	u16 nnodes = clamp_u16(read_u16(fp), 0, TED_MAX_NODES);
+	for (u16 i = 0; i < nnodes; ++i) {
+		session_read_node(ted, fp);
+	}
+
+	u16 nbuffers = clamp_u16(read_u16(fp), 0, TED_MAX_BUFFERS);
+	for (u16 i = 0; i < nbuffers; ++i) {
+		session_read_buffer(ted, fp);
+	}
+
+	if (ted->nodes_used[active_node_idx])
+		ted->active_node = &ted->nodes[active_node_idx];
+	if (ted->buffers_used[active_buffer_idx])
+		ted->active_buffer = &ted->buffers[active_buffer_idx];
+}
+
+static void session_write(Ted *ted) {
+	Settings const *settings = &ted->settings;
+	if (!settings->restore_session)
+		return;
+	// first we write to a prefixed file so in case something goes wrong we still have the old session.
+	char filename1[TED_PATH_MAX], filename2[TED_PATH_MAX];
+	strbuf_printf(filename1, "%s/_" SESSION_FILENAME, ted->local_data_dir);
+	strbuf_printf(filename2, "%s/"  SESSION_FILENAME, ted->local_data_dir);
+	FILE *fp = fopen(filename1, "wb");
+	if (fp) {
+		session_write_file(ted, fp);
+
+		bool success = !ferror(fp);
+		success &= fclose(fp) == 0;
+		if (success)
+			rename(filename1, filename2); // overwrite old session
+	}
+}
+
+static void session_read(Ted *ted) {
+	Settings const *settings = &ted->settings;
+	if (settings->restore_session) {
+		char filename[TED_PATH_MAX];
+		strbuf_printf(filename, "%s/" SESSION_FILENAME, ted->local_data_dir);
+		FILE *fp = fopen(filename, "rb");
+		if (fp) {
+			session_read_file(ted, fp);
+			fclose(fp);
+		}
+	}
+}