feat(core): 添加 command 定义及 command_buffer 维护功能

src/core/command.h

@@ -0,0 +1,38 @@
+#pragma once
+
+#include "core/types.h"
+#include "core/wm_desc.h"
+
+typedef enum command_type_t {
+  ZDWM_COMMAND_MANAGE_WINDOW,
+  ZDWM_COMMAND_SWITCH_WORKSPACE
+} command_type_t;
+
+typedef struct manage_window_command_t {
+  workspace_id_t workspace;
+  bool floating;
+  bool switch_to_workspace;
+  window_info_t info;
+} manage_window_command_t;
+
+typedef struct switch_workspace_command_t {
+  output_id_t output;
+  workspace_id_t workspace;
+} switch_workspace_command_t;
+
+/**
+ * @brief 非 owning 的命令值对象
+ * @details
+ * command_t 自身不拥有任何堆内存；其当前所有 payload 中出现的指针字段均为借用
+ * 语义。
+ *
+ * 因此 command_t 支持按值浅拷贝，且不需要单独的 cleanup 接口。若接收方需要在
+ * 源数据生命周期之外继续持有相关内容，必须自行复制。
+ */
+typedef struct command_t {
+  command_type_t type;
+  union {
+    manage_window_command_t manage_window;
+    switch_workspace_command_t switch_workspace;
+  } as;
+} command_t;

src/core/command_buffer.c

@@ -0,0 +1,23 @@
+#include "core/command_buffer.h"
+
+#include "base/array.h"
+#include "base/memory.h"
+#include "core/command.h"
+
+void command_buffer_reset(command_buffer_t *buffer) {
+  if (!buffer->items || !buffer->capacity) return;
+
+  p_clear(buffer->items, buffer->capacity);
+  buffer->count = 0;
+}
+
+void command_buffer_cleanup(command_buffer_t *buffer) {
+  p_delete(&buffer->items);
+  buffer->count = 0;
+  buffer->capacity = 0;
+}
+
+void command_buffer_push(command_buffer_t *buffer, const command_t *command) {
+  command_t *cmd = array_push(buffer->items, buffer->count, buffer->capacity);
+  *cmd = *command;
+}

src/core/command_buffer.h

@@ -0,0 +1,15 @@
+#pragma once
+
+#include <stddef.h>
+
+#include "core/command.h"
+
+typedef struct command_buffer_t {
+  command_t *items;
+  size_t count;
+  size_t capacity;
+} command_buffer_t;
+
+void command_buffer_reset(command_buffer_t *buffer);
+void command_buffer_cleanup(command_buffer_t *buffer);
+void command_buffer_push(command_buffer_t *buffer, const command_t *command);

src/core/runtime.h

@@ -3,6 +3,7 @@
 #include <stddef.h>
 
 #include "core/backend.h"
+#include "core/command_buffer.h"
 #include "core/layout.h"
 #include "core/rules.h"
 #include "core/state.h"
@@ -23,6 +24,7 @@ typedef struct runtime_t {
   bool running;
   bool will_restart;
 
+  command_buffer_t command_buffer;
   state_t state;
   layout_registry_t layouts;
   rules_t rules;