path: root/e-util/e-plugin-mono.c

#include <sys/types.h>
#include <dirent.h>
#include <string.h>

#include "e-plugin-mono.h"

#include <mono/metadata/debug-helpers.h>
#include <mono/metadata/object.h>
#include <mono/metadata/appdomain.h>
#include <mono/metadata/assembly.h>
#include <mono/jit/jit.h>

#define d(x)

static MonoDomain *domain;

/* ********************************************************************** */
static void *epm_parent_class;

typedef struct _EPluginMonoPrivate {
    MonoAssembly *assembly;
    MonoClass *klass;
    MonoObject *plugin;
    GHashTable *methods;
} EPluginMonoPrivate;

#define epm ((EPluginMono *)ep)

static char *
get_xml_prop(xmlNodePtr node, const char *id)
{
    char *p = xmlGetProp(node, id);
    char *out = NULL;

    if (p) {
        out = g_strdup(p);
        xmlFree(p);
    }

    return out;
}

/*
  Two approaches:
   You can have a Evolution.Plugin implementation which has every callback as methods on it.
   Or you can just use static methods for everything.

   All methods take a single (structured) argument.
*/

static void *
epm_invoke(EPlugin *ep, const char *name, void *data)
{
    EPluginMonoPrivate *p = epm->priv;
    MonoMethodDesc *d;
    MonoMethod *m;
    MonoObject *x = NULL, *res;
    void **params;

    /* we need to do this every time since we may be called from any thread for some uses */
    mono_thread_attach(domain);

    if (p->assembly == NULL) {
        p->assembly = mono_domain_assembly_open(domain, epm->location);
        if (p->assembly == NULL) {
            g_warning("can't load assembly '%s'", epm->location);
            return NULL;
        }

        if (epm->handler == NULL
            || (p->klass = mono_class_from_name(mono_assembly_get_image(p->assembly), "", epm->handler)) == NULL) {
            d(printf("Using static callbacks only"));
        } else {
            p->plugin = mono_object_new(domain, p->klass);
            /* could conceivably init with some context too */
            mono_runtime_object_init(p->plugin);
        }
    }

    m = g_hash_table_lookup(p->methods, name);
    if (m == NULL) {
        if (p->klass) {
            d(printf("looking up method '%s' in class\n", name));
            /* class method */
            d = mono_method_desc_new(name, FALSE);
            if (d == NULL) {
                g_warning("Can't create method descriptor for '%s'", name);
                return NULL;
            }

            m = mono_method_desc_search_in_class(d, p->klass);
            if (m == NULL) {
                g_warning("Can't find method callback '%s'", name);
                return NULL;
            }
        } else {
            d(printf("looking up static method '%s'\n", name));
            /* static method */
            d = mono_method_desc_new(name, FALSE);
            if (d == NULL) {
                g_warning("Can't create method descriptor for '%s'", name);
                return NULL;
            }

            m = mono_method_desc_search_in_image(d, mono_assembly_get_image(p->assembly));
            if (m == NULL) {
                g_warning("Can't find method callback '%s'", name);
                return NULL;
            }
        }

        g_hash_table_insert(p->methods, g_strdup(name), m);
    }

    params = g_malloc0(sizeof(*params)*1);
    params[0] = &data;
    res = mono_runtime_invoke(m, p->plugin, params, &x);
    /* do i need to free params?? */

    if (x)
        mono_print_unhandled_exception(x);

    if (res) {
        void **p = mono_object_unbox(res);
        d(printf("mono method returned '%p' %ld\n", *p, (long int)*p));
        return *p;
    } else
        return NULL;
}

static int
epm_construct(EPlugin *ep, xmlNodePtr root)
{
    if (((EPluginClass *)epm_parent_class)->construct(ep, root) == -1)
        return -1;

    epm->location = get_xml_prop(root, "location");
    epm->handler = get_xml_prop(root, "handler");

    if (epm->location == NULL)
        return -1;

    return 0;
}

static void
epm_finalise(GObject *o)
{
    EPlugin *ep = (EPlugin *)o;
    EPluginMonoPrivate *p = epm->priv;

    g_free(epm->location);
    g_free(epm->handler);

    g_hash_table_foreach(p->methods, (GHFunc)g_free, NULL);
    g_hash_table_destroy(p->methods);

    g_free(epm->priv);

    ((GObjectClass *)epm_parent_class)->finalize(o);
}

static void
epm_class_init(EPluginClass *klass)
{
    ((GObjectClass *)klass)->finalize = epm_finalise;
    klass->construct = epm_construct;
    klass->invoke = epm_invoke;
    klass->type = "mono";
}

static void
epm_init(GObject *o)
{
    EPlugin *ep = (EPlugin *)o;

    epm->priv = g_malloc0(sizeof(*epm->priv));
    epm->priv->methods = g_hash_table_new(g_str_hash, g_str_equal);
}

GType
e_plugin_mono_get_type(void)
{
    static GType type = 0;
    
    if (!type) {
        static const GTypeInfo info = {
            sizeof(EPluginMonoClass), NULL, NULL, (GClassInitFunc) epm_class_init, NULL, NULL,
            sizeof(EPluginMono), 0, (GInstanceInitFunc) epm_init,
        };

        epm_parent_class = g_type_class_ref(e_plugin_get_type());
        type = g_type_register_static(e_plugin_get_type(), "EPluginMono", &info, 0);
        domain = mono_jit_init("Evolution");
        mono_thread_attach(domain);
    }
    
    return type;
}