dfhack/plugins/examples/skeleton.cpp

// This is an example plugin that documents and implements all the plugin
// callbacks and features. You can include it in the regular build by setting
// the BUILD_SKELETON option in CMake to ON. Play with loading and unloading
// the plugin in various game states (e.g. with and without a world loaded),
// and see the debug messages get printed to the console.
//
// See the other example plugins in this directory for plugins that are
// configured for specific use cases (but don't come with as many comments as
// this one does).

#include <string>
#include <vector>

#include "df/world.h"

#include "Core.h"
#include "Debug.h"
#include "LuaTools.h"
#include "PluginManager.h"

#include "modules/Persistence.h"
#include "modules/World.h"

using std::string;
using std::vector;

using namespace DFHack;

// Expose the plugin name to the DFHack core, as well as metadata like the
// DFHack version that this plugin was compiled with. This macro provides a
// variable for the plugin name as const char * plugin_name.
// The name provided must correspond to the filename --
// skeleton.plug.so, skeleton.plug.dylib, or skeleton.plug.dll in this case
DFHACK_PLUGIN("skeleton");

// The identifier declared with this macro (i.e. is_enabled) is used to track
// whether the plugin is in an "enabled" state. If you don't need enablement
// for your plugin, you don't need this line. This variable will also be read
// by the `plug` builtin command; when true the plugin will be shown as enabled.
DFHACK_PLUGIN_IS_ENABLED(is_enabled);

// Any globals a plugin requires (e.g. world) should be listed here.
// For example, this line expands to "using df::global::world" and prevents the
// plugin from being loaded if df::global::world is null (i.e. missing from
// symbols.xml).
REQUIRE_GLOBAL(world);

// logging levels can be dynamically controlled with the `debugfilter` command.
// Actual plugins will likely want to set the default level to LINFO or LWARNING
// instead of the LDEBUG used here.
namespace DFHack {
    // for configuration-related logging
    DBG_DECLARE(skeleton, status, DebugCategory::LDEBUG);
    // run `debugfilter set debug skeleton onupdate` to see logging in plugin_onupdate
    DBG_DECLARE(skeleton, onupdate, DebugCategory::LINFO);
    // for command-related logging
    DBG_DECLARE(skeleton, command, DebugCategory::LDEBUG);
}

static command_result command_callback1(color_ostream &out, vector<string> &parameters);

// run when the plugin is loaded
DFhackCExport command_result plugin_init(color_ostream &out, std::vector<PluginCommand> &commands) {
    DEBUG(status,out).print("initializing %s\n", plugin_name);

    // For in-tree plugins, don't use the "usage" parameter of PluginCommand.
    // Instead, add an .rst file with the same name as the plugin to the
    // docs/plugins/ directory.
    commands.push_back(PluginCommand(
        "skeleton",
        "Short (~54 character) description of command.", // to use one line in the ``[DFHack]# ls`` output
        command_callback1));
    return CR_OK;
}

// run when the plugin is unloaded
DFhackCExport command_result plugin_shutdown(color_ostream &out) {
    DEBUG(status,out).print("shutting down %s\n", plugin_name);

    // You *MUST* kill all threads you created before this returns.
    // If everything fails, just return CR_FAILURE. Your plugin will be
    // in a zombie state, but things won't crash.
    return CR_OK;

}

// run when the `enable` or `disable` command is run with this plugin name as
// an argument
DFhackCExport command_result plugin_enable(color_ostream &out, bool enable) {
    DEBUG(status,out).print("%s from the API\n", enable ? "enabled" : "disabled");

    // you have to maintain the state of the is_enabled variable yourself. it
    // doesn't happen automatically.
    is_enabled = enable;
    return CR_OK;
}

// Called to notify the plugin about important state changes.
// Invoked with DF suspended, and always before the matching plugin_onupdate.
// More event codes may be added in the future.
DFhackCExport command_result plugin_onstatechange(color_ostream &out, state_change_event event) {
    DEBUG(status,out).print("game state changed: %d\n", event);

    if (is_enabled) {
        switch (event) {
            case SC_UNKNOWN:
                break;
            case SC_WORLD_LOADED:
                break;
            case SC_WORLD_UNLOADED:
                break;
            case SC_MAP_LOADED:
                break;
            case SC_MAP_UNLOADED:
                break;
            case SC_VIEWSCREEN_CHANGED:
                break;
            case SC_CORE_INITIALIZED:
                break;
            case SC_BEGIN_UNLOAD:
                break;
            case SC_PAUSED:
                break;
            case SC_UNPAUSED:
                break;
        }
    }

    return CR_OK;
}

// Whatever you put here will be done in each game frame refresh. Don't abuse it.
// Note that if the plugin implements the enabled API, this function is only called
// if the plugin is enabled.
DFhackCExport command_result plugin_onupdate (color_ostream &out) {
    DEBUG(onupdate,out).print("onupdate called\n");

    return CR_OK;
}

// If you need to save or load world-specific data, define these functions.
// plugin_save_data is called when the game might be about to save the world,
// and plugin_load_data is called whenever a new world is loaded. If the plugin
// is loaded or unloaded while a world is active, plugin_save_data or
// plugin_load_data will be called immediately.
DFhackCExport command_result plugin_save_data (color_ostream &out) {
    DEBUG(status,out).print("save or unload is imminent; time to persist state\n");

    // Call functions in the Persistence module here.
    return CR_OK;
}

DFhackCExport command_result plugin_load_data (color_ostream &out) {
    DEBUG(status,out).print("world is loading; time to load persisted state\n");

    // Call functions in the Persistence module here.
    return CR_OK;
}

// define the structure that will represent the possible commandline options
struct command_options {
    // whether to display help
    bool help = false;

    // whether to run a cycle right now
    bool now = false;

    // how many ticks to wait between cycles when enabled, -1 means unset
    int32_t ticks = -1;

    // example params of different types
    df::coord start;
    string format;
    vector<string*> list; // note this must be a vector of pointers, not objects

    static struct_identity _identity;
};
static const struct_field_info command_options_fields[] = {
    { struct_field_info::PRIMITIVE,      "help",   offsetof(command_options, help),  &df::identity_traits<bool>::identity,    0, 0 },
    { struct_field_info::PRIMITIVE,      "now",    offsetof(command_options, now),   &df::identity_traits<bool>::identity,    0, 0 },
    { struct_field_info::PRIMITIVE,      "ticks",  offsetof(command_options, ticks), &df::identity_traits<int32_t>::identity, 0, 0 },
    { struct_field_info::SUBSTRUCT,      "start",  offsetof(command_options, start), &df::coord::_identity,                   0, 0 },
    { struct_field_info::PRIMITIVE,      "format", offsetof(command_options, format), df::identity_traits<string>::get(),     0, 0 },
    { struct_field_info::STL_VECTOR_PTR, "list",   offsetof(command_options, list),   df::identity_traits<string>::get(),     0, 0 },
    { struct_field_info::END }
};
struct_identity command_options::_identity(sizeof(command_options), &df::allocator_fn<command_options>, NULL, "command_options", NULL, command_options_fields);

// load the lua module associated with the plugin and parse the commandline
// in lua (which has better facilities than C++ for string parsing). You should
// create a file named after your plugin in the plugins/lua directory. This
// example expects you to define a global function in that file named
// "parse_commandline" that takes the options struct defined above along with
// the commandline parameters. It should parse the parameters and set data in
// the options structure. See plugins/lua/skeleton.lua for an example.
static bool get_options(color_ostream &out,
                        command_options &opts,
                        const vector<string> &parameters)
{
    auto L = Lua::Core::State;
    Lua::StackUnwinder top(L);

    if (!lua_checkstack(L, parameters.size() + 2) ||
        !Lua::PushModulePublic(
            out, L, ("plugins." + string(plugin_name)).c_str(),
            "parse_commandline")) {
        out.printerr("Failed to load %s Lua code\n", plugin_name);
        return false;
    }

    Lua::Push(L, &opts);
    for (const string &param : parameters)
        Lua::Push(L, param);

    if (!Lua::SafeCall(out, L, parameters.size() + 1, 0))
        return false;

    return true;
}

// This is the callback we registered in plugin_init. Note that while plugin
// callbacks are called with the core suspended, command callbacks are called
// from a different thread and need to explicity suspend the core if they
// interact with Lua or DF game state (most commands do at least one of these).
static command_result command_callback1(color_ostream &out, vector<string> &parameters) {
    DEBUG(command,out).print("%s command called with %zu parameters\n",
        plugin_name, parameters.size());

    // I'll say it again: always suspend the core in command callbacks unless
    // all your data is local.
    CoreSuspender suspend;

    // Return CR_WRONG_USAGE to print out your help text. The help text is
    // sourced from the associated rst file in docs/plugins/. The same help will
    // also be returned by 'help your-command'.
    command_options opts;
    if (!get_options(out, opts, parameters) || opts.help)
        return CR_WRONG_USAGE;

    // TODO: do something according to the flags set in the options struct

    return CR_OK;
}