Python: split module initialization from WSGI implementation.

This is required for futher ASGI implementation.

1 files changed, 331 insertions, 0 deletions

diff --git a/src/python/nxt_python.c b/src/python/nxt_python.c
new file mode 100644
index 00000000..5b6021bb
--- /dev/null
+++ b/src/python/nxt_python.c
@@ -0,0 +1,331 @@
+
+/*
+ * Copyright (C) NGINX, Inc.
+ */
+
+
+#include <Python.h>
+
+#include <nxt_main.h>
+#include <nxt_router.h>
+#include <nxt_unit.h>
+
+#include <python/nxt_python.h>
+
+#include NXT_PYTHON_MOUNTS_H
+
+
+#if PY_MAJOR_VERSION == 3
+#define PyString_FromStringAndSize(str, size)                                 \
+            PyUnicode_DecodeLatin1((str), (size), "strict")
+
+#else
+#define PyUnicode_InternInPlace     PyString_InternInPlace
+#endif
+
+static nxt_int_t nxt_python_start(nxt_task_t *task,
+    nxt_process_data_t *data);
+static void nxt_python_atexit(void);
+
+static uint32_t  compat[] = {
+    NXT_VERNUM, NXT_DEBUG,
+};
+
+
+NXT_EXPORT nxt_app_module_t  nxt_app_module = {
+    sizeof(compat),
+    compat,
+    nxt_string("python"),
+    PY_VERSION,
+    nxt_python_mounts,
+    nxt_nitems(nxt_python_mounts),
+    NULL,
+    nxt_python_start,
+};
+
+static PyObject           *nxt_py_stderr_flush;
+PyObject                  *nxt_py_application;
+
+#if PY_MAJOR_VERSION == 3
+static wchar_t            *nxt_py_home;
+#else
+static char               *nxt_py_home;
+#endif
+
+
+static nxt_int_t
+nxt_python_start(nxt_task_t *task, nxt_process_data_t *data)
+{
+    int                    rc;
+    char                   *nxt_py_module;
+    size_t                 len;
+    PyObject               *obj, *pypath, *module;
+    nxt_unit_ctx_t         *unit_ctx;
+    nxt_unit_init_t        python_init;
+    nxt_common_app_conf_t  *app_conf;
+    nxt_python_app_conf_t  *c;
+#if PY_MAJOR_VERSION == 3
+    char                   *path;
+    size_t                 size;
+    nxt_int_t              pep405;
+
+    static const char pyvenv[] = "/pyvenv.cfg";
+    static const char bin_python[] = "/bin/python";
+#endif
+
+    app_conf = data->app;
+    c = &app_conf->u.python;
+
+    if (c->home != NULL) {
+        len = nxt_strlen(c->home);
+
+#if PY_MAJOR_VERSION == 3
+
+        path = nxt_malloc(len + sizeof(pyvenv));
+        if (nxt_slow_path(path == NULL)) {
+            nxt_alert(task, "Failed to allocate memory");
+            return NXT_ERROR;
+        }
+
+        nxt_memcpy(path, c->home, len);
+        nxt_memcpy(path + len, pyvenv, sizeof(pyvenv));
+
+        pep405 = (access(path, R_OK) == 0);
+
+        nxt_free(path);
+
+        if (pep405) {
+            size = (len + sizeof(bin_python)) * sizeof(wchar_t);
+
+        } else {
+            size = (len + 1) * sizeof(wchar_t);
+        }
+
+        nxt_py_home = nxt_malloc(size);
+        if (nxt_slow_path(nxt_py_home == NULL)) {
+            nxt_alert(task, "Failed to allocate memory");
+            return NXT_ERROR;
+        }
+
+        if (pep405) {
+            mbstowcs(nxt_py_home, c->home, len);
+            mbstowcs(nxt_py_home + len, bin_python, sizeof(bin_python));
+            Py_SetProgramName(nxt_py_home);
+
+        } else {
+            mbstowcs(nxt_py_home, c->home, len + 1);
+            Py_SetPythonHome(nxt_py_home);
+        }
+
+#else
+        nxt_py_home = nxt_malloc(len + 1);
+        if (nxt_slow_path(nxt_py_home == NULL)) {
+            nxt_alert(task, "Failed to allocate memory");
+            return NXT_ERROR;
+        }
+
+        nxt_memcpy(nxt_py_home, c->home, len + 1);
+        Py_SetPythonHome(nxt_py_home);
+#endif
+    }
+
+    Py_InitializeEx(0);
+
+    module = NULL;
+    obj = NULL;
+
+    obj = PySys_GetObject((char *) "stderr");
+    if (nxt_slow_path(obj == NULL)) {
+        nxt_alert(task, "Python failed to get \"sys.stderr\" object");
+        goto fail;
+    }
+
+    nxt_py_stderr_flush = PyObject_GetAttrString(obj, "flush");
+    if (nxt_slow_path(nxt_py_stderr_flush == NULL)) {
+        nxt_alert(task, "Python failed to get \"flush\" attribute of "
+                        "\"sys.stderr\" object");
+        goto fail;
+    }
+
+    /* obj is a Borrowed reference. */
+
+    if (c->path.length > 0) {
+        obj = PyString_FromStringAndSize((char *) c->path.start,
+                                         c->path.length);
+
+        if (nxt_slow_path(obj == NULL)) {
+            nxt_alert(task, "Python failed to create string object \"%V\"",
+                      &c->path);
+            goto fail;
+        }
+
+        pypath = PySys_GetObject((char *) "path");
+
+        if (nxt_slow_path(pypath == NULL)) {
+            nxt_alert(task, "Python failed to get \"sys.path\" list");
+            goto fail;
+        }
+
+        if (nxt_slow_path(PyList_Insert(pypath, 0, obj) != 0)) {
+            nxt_alert(task, "Python failed to insert \"%V\" into \"sys.path\"",
+                      &c->path);
+            goto fail;
+        }
+
+        Py_DECREF(obj);
+    }
+
+    obj = Py_BuildValue("[s]", "unit");
+    if (nxt_slow_path(obj == NULL)) {
+        nxt_alert(task, "Python failed to create the \"sys.argv\" list");
+        goto fail;
+    }
+
+    if (nxt_slow_path(PySys_SetObject((char *) "argv", obj) != 0)) {
+        nxt_alert(task, "Python failed to set the \"sys.argv\" list");
+        goto fail;
+    }
+
+    Py_CLEAR(obj);
+
+    nxt_py_module = nxt_alloca(c->module.length + 1);
+    nxt_memcpy(nxt_py_module, c->module.start, c->module.length);
+    nxt_py_module[c->module.length] = '\0';
+
+    module = PyImport_ImportModule(nxt_py_module);
+    if (nxt_slow_path(module == NULL)) {
+        nxt_alert(task, "Python failed to import module \"%s\"", nxt_py_module);
+        nxt_python_print_exception();
+        goto fail;
+    }
+
+    obj = PyDict_GetItemString(PyModule_GetDict(module), "application");
+    if (nxt_slow_path(obj == NULL)) {
+        nxt_alert(task, "Python failed to get \"application\" "
+                  "from module \"%s\"", nxt_py_module);
+        goto fail;
+    }
+
+    if (nxt_slow_path(PyCallable_Check(obj) == 0)) {
+        nxt_alert(task, "\"application\" in module \"%s\" "
+                  "is not a callable object", nxt_py_module);
+        goto fail;
+    }
+
+    nxt_py_application = obj;
+    obj = NULL;
+
+    Py_INCREF(nxt_py_application);
+
+    Py_CLEAR(module);
+
+    nxt_unit_default_init(task, &python_init);
+
+    python_init.shm_limit = data->app->shm_limit;
+
+    rc = nxt_python_wsgi_init(task, &python_init);
+    if (nxt_slow_path(rc == NXT_ERROR)) {
+        goto fail;
+    }
+
+    unit_ctx = nxt_unit_init(&python_init);
+    if (nxt_slow_path(unit_ctx == NULL)) {
+        goto fail;
+    }
+
+    rc = nxt_python_wsgi_run(unit_ctx);
+
+    nxt_unit_done(unit_ctx);
+
+    nxt_python_atexit();
+
+    exit(rc);
+
+    return NXT_OK;
+
+fail:
+
+    Py_XDECREF(obj);
+    Py_XDECREF(module);
+
+    nxt_python_atexit();
+
+    return NXT_ERROR;
+}
+
+
+nxt_int_t
+nxt_python_init_strings(nxt_python_string_t *pstr)
+{
+    PyObject  *obj;
+
+    while (pstr->string.start != NULL) {
+        obj = PyString_FromStringAndSize((char *) pstr->string.start,
+                                         pstr->string.length);
+        if (nxt_slow_path(obj == NULL)) {
+            return NXT_ERROR;
+        }
+
+        PyUnicode_InternInPlace(&obj);
+
+        *pstr->object_p = obj;
+
+        pstr++;
+    }
+
+    return NXT_OK;
+}
+
+
+void
+nxt_python_done_strings(nxt_python_string_t *pstr)
+{
+    PyObject  *obj;
+
+    while (pstr->string.start != NULL) {
+        obj = *pstr->object_p;
+
+        Py_XDECREF(obj);
+        *pstr->object_p = NULL;
+
+        pstr++;
+    }
+}
+
+
+static void
+nxt_python_atexit(void)
+{
+    nxt_python_wsgi_done();
+
+    Py_XDECREF(nxt_py_stderr_flush);
+    Py_XDECREF(nxt_py_application);
+
+    Py_Finalize();
+
+    if (nxt_py_home != NULL) {
+        nxt_free(nxt_py_home);
+    }
+}
+
+
+void
+nxt_python_print_exception(void)
+{
+    PyErr_Print();
+
+#if PY_MAJOR_VERSION == 3
+    /* The backtrace may be buffered in sys.stderr file object. */
+    {
+        PyObject  *result;
+
+        result = PyObject_CallFunction(nxt_py_stderr_flush, NULL);
+        if (nxt_slow_path(result == NULL)) {
+            PyErr_Clear();
+            return;
+        }
+
+        Py_DECREF(result);
+    }
+#endif
+}