add js to tree

git-svn-id: http://svn.freeswitch.org/svn/freeswitch/trunk@3693 d0543943-73ff-0310-b7d9-9358b9ac24b2

libs/js/src/jsdso.c

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+/* -*- Mode: C; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 4 -*-
+ *
+ * ***** BEGIN LICENSE BLOCK *****
+ * Version: MPL 1.1/GPL 2.0/LGPL 2.1
+ *
+ * The contents of this file are subject to the Mozilla Public License Version
+ * 1.1 (the "License"); you may not use this file except in compliance with
+ * the License. You may obtain a copy of the License at
+ * http://www.mozilla.org/MPL/
+ *
+ * Software distributed under the License is distributed on an "AS IS" basis,
+ * WITHOUT WARRANTY OF ANY KIND, either express or implied. See the License
+ * for the specific language governing rights and limitations under the
+ * License.
+ *
+ * Contributor(s):
+ *
+ * Alternatively, the contents of this file may be used under the terms of
+ * either of the GNU General Public License Version 2 or later (the "GPL"),
+ * or the GNU Lesser General Public License Version 2.1 or later (the "LGPL"),
+ * in which case the provisions of the GPL or the LGPL are applicable instead
+ * of those above. If you wish to allow use of your version of this file only
+ * under the terms of either the GPL or the LGPL, and not to allow others to
+ * use your version of this file under the terms of the MPL, indicate your
+ * decision by deleting the provisions above and replace them with the notice
+ * and other provisions required by the GPL or the LGPL. If you do not delete
+ * the provisions above, a recipient may use your version of this file under
+ * the terms of any one of the MPL, the GPL or the LGPL.
+ *
+ * ***** END LICENSE BLOCK ***** */
+
+/* ATTENTION: This is an OSSP js extension to the Mozilla JavaScript engine.
+   It was implemented by Ralf S. Engelschall <rse@engelschall.com> for OSSP. */
+
+#if defined(OSSP) && defined(JS_HAS_DSO_OBJECT) && JS_HAS_DSO_OBJECT
+
+/* own headers (part 1/2) */
+#include "jsstddef.h"
+
+/* system headers */
+#include <stdio.h>
+#include <stdlib.h>
+#include <dlfcn.h>
+
+/* own headers (part 2/2) */
+#include "jstypes.h"
+#include "jsapi.h"
+#include "jsatom.h"
+#include "jscntxt.h"
+#include "jsconfig.h"
+#include "jsobj.h"
+#include "jsdso.h"
+
+/* process local storage of DSO handles */
+static void *dso_handle[10000];
+
+/* type of the DSO load/unload functions */
+typedef JSBool (*dso_func_t)(JSContext *cx);
+
+/* ISO-C type coersion trick */
+typedef union { void *vp; dso_func_t fp; } dso_func_ptr_t;
+
+/* public C API function: DSO loading */
+JS_PUBLIC_API(JSBool)
+JS_DSOLoad(JSContext *cx, int *idp, const char *filename)
+{
+    int id;
+    void *handle;
+    dso_func_ptr_t func;
+    JSBool rc;
+
+    /* determine next free DSO handle slot */
+    for (id = 0; dso_handle[id] != NULL && id < sizeof(dso_handle)/sizeof(dso_handle[0]); id++)
+        ;
+    if (id == sizeof(dso_handle)/sizeof(dso_handle[0])) {
+        JS_ReportError(cx, "no more free DSO handle slots available");
+        return JS_FALSE;
+    }
+
+    /* load DSO into process */
+    if ((handle = dlopen(filename, RTLD_NOW)) == NULL) {
+        JS_ReportError(cx, "unable to load DSO \"%s\": %s", filename, dlerror());
+        return JS_FALSE;
+    }
+
+    /* resolve "js_DSO_load" function, call it and insist on a true return */
+    if ((func.vp = dlsym(handle, "js_DSO_load")) == NULL) {
+        JS_ReportError(cx, "unable to resolve symbol \"js_DSO_load\" in DSO \"%s\"", filename);
+        dlclose(handle);
+        return JS_FALSE;
+    }
+    rc = func.fp(cx);
+    if (!rc) {
+        JS_ReportError(cx, "function \"js_DSO_load\" in DSO \"%s\" returned error", filename);
+        dlclose(handle);
+        return JS_FALSE;
+    }
+
+    /* store DSO handle into process local storage */
+    dso_handle[id] = handle;
+
+    /* return DSO id to caller */
+    if (idp != NULL)
+        *idp = id;
+
+    return JS_TRUE;
+}
+
+/* public C API function: DSO unloading */
+JS_PUBLIC_API(JSBool)
+JS_DSOUnload(JSContext *cx, int id)
+{
+    int idx;
+    void *handle;
+    dso_func_ptr_t func;
+    JSBool rc;
+
+    /* sanity check DSO id */
+    if (id < 0 || id >= sizeof(dso_handle)/sizeof(dso_handle[0])) {
+        JS_ReportError(cx, "invalid argument: DSO id #%d out of range", id);
+        return JS_FALSE;
+    }
+
+    /* determine DSO handle */
+    if ((handle = dso_handle[id]) == NULL) {
+        JS_ReportError(cx, "invalid argument: DSO id #%d currently unused", id);
+        return JS_FALSE;
+    }
+
+    /* resolve "js_DSO_unload" function and (if available only)
+       call it and insist on a true return */
+    if ((func.vp = dlsym(handle, "js_DSO_unload")) != NULL) {
+        rc = func.fp(cx);
+        if (!rc) {
+            JS_ReportError(cx, "function \"js_DSO_unload\" in DSO with id #%d returned error", idx);
+            return JS_FALSE;
+        }
+    }
+
+    /* unload DSO from process */
+    dlclose(handle);
+
+    /* free DSO handle slot */
+    dso_handle[id] = NULL;
+
+    return JS_TRUE;
+}
+
+/* global JavaScript language DSO object method: id = DSO.load("filename.so") */
+static JSBool dso_load(JSContext *cx, JSObject *obj, uintN argc, jsval *argv, jsval *rval)
+{
+    JSString *filename;
+    char *c_filename;
+    int id;
+
+    /* usage sanity checks */
+    if (argc == 0) {
+        JS_ReportError(cx, "usage: id = DSO.load(filename)");
+        return JS_FALSE;
+    }
+    if (argc != 1) {
+        JS_ReportError(cx, "invalid number of arguments: %d received, %d expected", argc, 1);
+        return JS_FALSE;
+    }
+
+    /* determine filename */
+    if ((filename = js_ValueToString(cx, argv[0])) == NULL) {
+        JS_ReportError(cx, "invalid argument");
+        return JS_FALSE;
+    }
+    if ((c_filename = JS_GetStringBytes(filename)) == NULL) {
+        JS_ReportError(cx, "invalid argument");
+        return JS_FALSE;
+    }
+
+    /* load DSO */
+    if (!JS_DSOLoad(cx, &id, c_filename))
+        return JS_FALSE;
+
+    /* return DSO handle id */
+    *rval = INT_TO_JSVAL(id);
+
+    return JS_TRUE;
+}
+
+/* global JavaScript language DSO object method: DSO.unload(id) */
+static JSBool dso_unload(JSContext *cx, JSObject *obj, uintN argc, jsval *argv, jsval *rval)
+{
+    int id;
+    JSBool rc;
+
+    /* usage sanity checks */
+    if (argc == 0) {
+        JS_ReportError(cx, "usage: DSO.unload(id)");
+        return JS_FALSE;
+    }
+    if (argc != 1) {
+        JS_ReportError(cx, "invalid number of arguments: %d received, %d expected", argc, 1);
+        return JS_FALSE;
+    }
+
+    /* determine DSO id */
+    id = JSVAL_TO_INT(argv[0]);
+
+    /* unload DSO */
+    if (!JS_DSOUnload(cx, id))
+        return JS_FALSE;
+
+    return JS_TRUE;
+}
+
+/* JavaScript DSO class method definitions */
+static JSFunctionSpec dso_methods[] = {
+    { "load",   dso_load,   1, 0, 0 },
+    { "unload", dso_unload, 1, 0, 0 },
+    { NULL,     NULL,       0, 0, 0 }
+};
+
+/* JavaScript DSO class definition */
+static JSClass dso_class = {
+    "DSO",
+    0,
+    JS_PropertyStub,
+    JS_PropertyStub,
+    JS_PropertyStub,
+    JS_PropertyStub,
+    JS_EnumerateStub,
+    JS_ResolveStub,
+    JS_ConvertStub,
+    JS_FinalizeStub,
+    JSCLASS_NO_OPTIONAL_MEMBERS
+};
+
+/* JavaScript DSO class global initializer */
+JSObject *js_InitDSOClass(JSContext *cx, JSObject *obj)
+{
+    JSObject *DSO;
+
+    if ((DSO = JS_DefineObject(cx, obj, "DSO", &dso_class, NULL, 0)) == NULL)
+        return NULL;
+    if (!JS_DefineFunctions(cx, DSO, dso_methods))
+        return NULL;
+    return DSO;
+}
+
+#endif /* JS_HAS_DSO_OBJECT */
+