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Diffstat (limited to 'generator/generator_python.ml')
-rw-r--r-- | generator/generator_python.ml | 570 |
1 files changed, 570 insertions, 0 deletions
diff --git a/generator/generator_python.ml b/generator/generator_python.ml new file mode 100644 index 00000000..2a6034d4 --- /dev/null +++ b/generator/generator_python.ml @@ -0,0 +1,570 @@ +(* libguestfs + * Copyright (C) 2009-2010 Red Hat Inc. + * + * This program is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License as published by + * the Free Software Foundation; either version 2 of the License, or + * (at your option) any later version. + * + * This program is distributed in the hope that it will be useful, + * but WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + * GNU General Public License for more details. + * + * You should have received a copy of the GNU General Public License + * along with this program; if not, write to the Free Software + * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA + *) + +(* Please read generator/README first. *) + +open Printf + +open Generator_types +open Generator_utils +open Generator_pr +open Generator_docstrings +open Generator_optgroups +open Generator_actions +open Generator_structs +open Generator_c + +(* Generate Python C module. *) +let rec generate_python_c () = + generate_header CStyle LGPLv2plus; + + pr "\ +#define PY_SSIZE_T_CLEAN 1 +#include <Python.h> + +#if PY_VERSION_HEX < 0x02050000 +typedef int Py_ssize_t; +#define PY_SSIZE_T_MAX INT_MAX +#define PY_SSIZE_T_MIN INT_MIN +#endif + +#include <stdio.h> +#include <stdlib.h> +#include <assert.h> + +#include \"guestfs.h\" + +#ifndef HAVE_PYCAPSULE_NEW +typedef struct { + PyObject_HEAD + guestfs_h *g; +} Pyguestfs_Object; +#endif + +static guestfs_h * +get_handle (PyObject *obj) +{ + assert (obj); + assert (obj != Py_None); +#ifndef HAVE_PYCAPSULE_NEW + return ((Pyguestfs_Object *) obj)->g; +#else + return (guestfs_h*) PyCapsule_GetPointer(obj, \"guestfs_h\"); +#endif +} + +static PyObject * +put_handle (guestfs_h *g) +{ + assert (g); +#ifndef HAVE_PYCAPSULE_NEW + return + PyCObject_FromVoidPtrAndDesc ((void *) g, (char *) \"guestfs_h\", NULL); +#else + return PyCapsule_New ((void *) g, \"guestfs_h\", NULL); +#endif +} + +/* This list should be freed (but not the strings) after use. */ +static char ** +get_string_list (PyObject *obj) +{ + size_t i, len; + char **r; + + assert (obj); + + if (!PyList_Check (obj)) { + PyErr_SetString (PyExc_RuntimeError, \"expecting a list parameter\"); + return NULL; + } + + Py_ssize_t slen = PyList_Size (obj); + if (slen == -1) { + PyErr_SetString (PyExc_RuntimeError, \"get_string_list: PyList_Size failure\"); + return NULL; + } + len = (size_t) slen; + r = malloc (sizeof (char *) * (len+1)); + if (r == NULL) { + PyErr_SetString (PyExc_RuntimeError, \"get_string_list: out of memory\"); + return NULL; + } + + for (i = 0; i < len; ++i) + r[i] = PyString_AsString (PyList_GetItem (obj, i)); + r[len] = NULL; + + return r; +} + +static PyObject * +put_string_list (char * const * const argv) +{ + PyObject *list; + int argc, i; + + for (argc = 0; argv[argc] != NULL; ++argc) + ; + + list = PyList_New (argc); + for (i = 0; i < argc; ++i) + PyList_SetItem (list, i, PyString_FromString (argv[i])); + + return list; +} + +static PyObject * +put_table (char * const * const argv) +{ + PyObject *list, *item; + int argc, i; + + for (argc = 0; argv[argc] != NULL; ++argc) + ; + + list = PyList_New (argc >> 1); + for (i = 0; i < argc; i += 2) { + item = PyTuple_New (2); + PyTuple_SetItem (item, 0, PyString_FromString (argv[i])); + PyTuple_SetItem (item, 1, PyString_FromString (argv[i+1])); + PyList_SetItem (list, i >> 1, item); + } + + return list; +} + +static void +free_strings (char **argv) +{ + int argc; + + for (argc = 0; argv[argc] != NULL; ++argc) + free (argv[argc]); + free (argv); +} + +static PyObject * +py_guestfs_create (PyObject *self, PyObject *args) +{ + guestfs_h *g; + + g = guestfs_create (); + if (g == NULL) { + PyErr_SetString (PyExc_RuntimeError, + \"guestfs.create: failed to allocate handle\"); + return NULL; + } + guestfs_set_error_handler (g, NULL, NULL); + /* This can return NULL, but in that case put_handle will have + * set the Python error string. + */ + return put_handle (g); +} + +static PyObject * +py_guestfs_close (PyObject *self, PyObject *args) +{ + PyObject *py_g; + guestfs_h *g; + + if (!PyArg_ParseTuple (args, (char *) \"O:guestfs_close\", &py_g)) + return NULL; + g = get_handle (py_g); + + guestfs_close (g); + + Py_INCREF (Py_None); + return Py_None; +} + +"; + + let emit_put_list_function typ = + pr "static PyObject *\n"; + pr "put_%s_list (struct guestfs_%s_list *%ss)\n" typ typ typ; + pr "{\n"; + pr " PyObject *list;\n"; + pr " size_t i;\n"; + pr "\n"; + pr " list = PyList_New (%ss->len);\n" typ; + pr " for (i = 0; i < %ss->len; ++i)\n" typ; + pr " PyList_SetItem (list, i, put_%s (&%ss->val[i]));\n" typ typ; + pr " return list;\n"; + pr "};\n"; + pr "\n" + in + + (* Structures, turned into Python dictionaries. *) + List.iter ( + fun (typ, cols) -> + pr "static PyObject *\n"; + pr "put_%s (struct guestfs_%s *%s)\n" typ typ typ; + pr "{\n"; + pr " PyObject *dict;\n"; + pr "\n"; + pr " dict = PyDict_New ();\n"; + List.iter ( + function + | name, FString -> + pr " PyDict_SetItemString (dict, \"%s\",\n" name; + pr " PyString_FromString (%s->%s));\n" + typ name + | name, FBuffer -> + pr " PyDict_SetItemString (dict, \"%s\",\n" name; + pr " PyString_FromStringAndSize (%s->%s, %s->%s_len));\n" + typ name typ name + | name, FUUID -> + pr " PyDict_SetItemString (dict, \"%s\",\n" name; + pr " PyString_FromStringAndSize (%s->%s, 32));\n" + typ name + | name, (FBytes|FUInt64) -> + pr " PyDict_SetItemString (dict, \"%s\",\n" name; + pr " PyLong_FromUnsignedLongLong (%s->%s));\n" + typ name + | name, FInt64 -> + pr " PyDict_SetItemString (dict, \"%s\",\n" name; + pr " PyLong_FromLongLong (%s->%s));\n" + typ name + | name, FUInt32 -> + pr " PyDict_SetItemString (dict, \"%s\",\n" name; + pr " PyLong_FromUnsignedLong (%s->%s));\n" + typ name + | name, FInt32 -> + pr " PyDict_SetItemString (dict, \"%s\",\n" name; + pr " PyLong_FromLong (%s->%s));\n" + typ name + | name, FOptPercent -> + pr " if (%s->%s >= 0)\n" typ name; + pr " PyDict_SetItemString (dict, \"%s\",\n" name; + pr " PyFloat_FromDouble ((double) %s->%s));\n" + typ name; + pr " else {\n"; + pr " Py_INCREF (Py_None);\n"; + pr " PyDict_SetItemString (dict, \"%s\", Py_None);\n" name; + pr " }\n" + | name, FChar -> + pr " PyDict_SetItemString (dict, \"%s\",\n" name; + pr " PyString_FromStringAndSize (&dirent->%s, 1));\n" name + ) cols; + pr " return dict;\n"; + pr "};\n"; + pr "\n"; + + ) structs; + + (* Emit a put_TYPE_list function definition only if that function is used. *) + List.iter ( + function + | typ, (RStructListOnly | RStructAndList) -> + (* generate the function for typ *) + emit_put_list_function typ + | typ, _ -> () (* empty *) + ) (rstructs_used_by all_functions); + + (* Python wrapper functions. *) + List.iter ( + fun (name, style, _, _, _, _, _) -> + pr "static PyObject *\n"; + pr "py_guestfs_%s (PyObject *self, PyObject *args)\n" name; + pr "{\n"; + + pr " PyObject *py_g;\n"; + pr " guestfs_h *g;\n"; + pr " PyObject *py_r;\n"; + + let error_code = + match fst style with + | RErr | RInt _ | RBool _ -> pr " int r;\n"; "-1" + | RInt64 _ -> pr " int64_t r;\n"; "-1" + | RConstString _ | RConstOptString _ -> + pr " const char *r;\n"; "NULL" + | RString _ -> pr " char *r;\n"; "NULL" + | RStringList _ | RHashtable _ -> pr " char **r;\n"; "NULL" + | RStruct (_, typ) -> pr " struct guestfs_%s *r;\n" typ; "NULL" + | RStructList (_, typ) -> + pr " struct guestfs_%s_list *r;\n" typ; "NULL" + | RBufferOut _ -> + pr " char *r;\n"; + pr " size_t size;\n"; + "NULL" in + + List.iter ( + function + | Pathname n | Device n | Dev_or_Path n | String n | Key n + | FileIn n | FileOut n -> + pr " const char *%s;\n" n + | OptString n -> pr " const char *%s;\n" n + | BufferIn n -> + pr " const char *%s;\n" n; + pr " Py_ssize_t %s_size;\n" n + | StringList n | DeviceList n -> + pr " PyObject *py_%s;\n" n; + pr " char **%s;\n" n + | Bool n -> pr " int %s;\n" n + | Int n -> pr " int %s;\n" n + | Int64 n -> pr " long long %s;\n" n + ) (snd style); + + pr "\n"; + + (* Convert the parameters. *) + pr " if (!PyArg_ParseTuple (args, (char *) \"O"; + List.iter ( + function + | Pathname _ | Device _ | Dev_or_Path _ | String _ | Key _ + | FileIn _ | FileOut _ -> pr "s" + | OptString _ -> pr "z" + | StringList _ | DeviceList _ -> pr "O" + | Bool _ -> pr "i" (* XXX Python has booleans? *) + | Int _ -> pr "i" + | Int64 _ -> pr "L" (* XXX Whoever thought it was a good idea to + * emulate C's int/long/long long in Python? + *) + | BufferIn _ -> pr "s#" + ) (snd style); + pr ":guestfs_%s\",\n" name; + pr " &py_g"; + List.iter ( + function + | Pathname n | Device n | Dev_or_Path n | String n | Key n + | FileIn n | FileOut n -> pr ", &%s" n + | OptString n -> pr ", &%s" n + | StringList n | DeviceList n -> pr ", &py_%s" n + | Bool n -> pr ", &%s" n + | Int n -> pr ", &%s" n + | Int64 n -> pr ", &%s" n + | BufferIn n -> pr ", &%s, &%s_size" n n + ) (snd style); + + pr "))\n"; + pr " return NULL;\n"; + + pr " g = get_handle (py_g);\n"; + List.iter ( + function + | Pathname _ | Device _ | Dev_or_Path _ | String _ | Key _ + | FileIn _ | FileOut _ | OptString _ | Bool _ | Int _ | Int64 _ + | BufferIn _ -> () + | StringList n | DeviceList n -> + pr " %s = get_string_list (py_%s);\n" n n; + pr " if (!%s) return NULL;\n" n + ) (snd style); + + pr "\n"; + + pr " r = guestfs_%s " name; + generate_c_call_args ~handle:"g" style; + pr ";\n"; + + List.iter ( + function + | Pathname _ | Device _ | Dev_or_Path _ | String _ | Key _ + | FileIn _ | FileOut _ | OptString _ | Bool _ | Int _ | Int64 _ + | BufferIn _ -> () + | StringList n | DeviceList n -> + pr " free (%s);\n" n + ) (snd style); + + pr " if (r == %s) {\n" error_code; + pr " PyErr_SetString (PyExc_RuntimeError, guestfs_last_error (g));\n"; + pr " return NULL;\n"; + pr " }\n"; + pr "\n"; + + (match fst style with + | RErr -> + pr " Py_INCREF (Py_None);\n"; + pr " py_r = Py_None;\n" + | RInt _ + | RBool _ -> pr " py_r = PyInt_FromLong ((long) r);\n" + | RInt64 _ -> pr " py_r = PyLong_FromLongLong (r);\n" + | RConstString _ -> pr " py_r = PyString_FromString (r);\n" + | RConstOptString _ -> + pr " if (r)\n"; + pr " py_r = PyString_FromString (r);\n"; + pr " else {\n"; + pr " Py_INCREF (Py_None);\n"; + pr " py_r = Py_None;\n"; + pr " }\n" + | RString _ -> + pr " py_r = PyString_FromString (r);\n"; + pr " free (r);\n" + | RStringList _ -> + pr " py_r = put_string_list (r);\n"; + pr " free_strings (r);\n" + | RStruct (_, typ) -> + pr " py_r = put_%s (r);\n" typ; + pr " guestfs_free_%s (r);\n" typ + | RStructList (_, typ) -> + pr " py_r = put_%s_list (r);\n" typ; + pr " guestfs_free_%s_list (r);\n" typ + | RHashtable n -> + pr " py_r = put_table (r);\n"; + pr " free_strings (r);\n" + | RBufferOut _ -> + pr " py_r = PyString_FromStringAndSize (r, size);\n"; + pr " free (r);\n" + ); + + pr " return py_r;\n"; + pr "}\n"; + pr "\n" + ) all_functions; + + (* Table of functions. *) + pr "static PyMethodDef methods[] = {\n"; + pr " { (char *) \"create\", py_guestfs_create, METH_VARARGS, NULL },\n"; + pr " { (char *) \"close\", py_guestfs_close, METH_VARARGS, NULL },\n"; + List.iter ( + fun (name, _, _, _, _, _, _) -> + pr " { (char *) \"%s\", py_guestfs_%s, METH_VARARGS, NULL },\n" + name name + ) all_functions; + pr " { NULL, NULL, 0, NULL }\n"; + pr "};\n"; + pr "\n"; + + (* Init function. *) + pr "\ +void +initlibguestfsmod (void) +{ + static int initialized = 0; + + if (initialized) return; + Py_InitModule ((char *) \"libguestfsmod\", methods); + initialized = 1; +} +" + +(* Generate Python module. *) +and generate_python_py () = + generate_header HashStyle LGPLv2plus; + + pr "\ +u\"\"\"Python bindings for libguestfs + +import guestfs +g = guestfs.GuestFS () +g.add_drive (\"guest.img\") +g.launch () +parts = g.list_partitions () + +The guestfs module provides a Python binding to the libguestfs API +for examining and modifying virtual machine disk images. + +Amongst the things this is good for: making batch configuration +changes to guests, getting disk used/free statistics (see also: +virt-df), migrating between virtualization systems (see also: +virt-p2v), performing partial backups, performing partial guest +clones, cloning guests and changing registry/UUID/hostname info, and +much else besides. + +Libguestfs uses Linux kernel and qemu code, and can access any type of +guest filesystem that Linux and qemu can, including but not limited +to: ext2/3/4, btrfs, FAT and NTFS, LVM, many different disk partition +schemes, qcow, qcow2, vmdk. + +Libguestfs provides ways to enumerate guest storage (eg. partitions, +LVs, what filesystem is in each LV, etc.). It can also run commands +in the context of the guest. Also you can access filesystems over +FUSE. + +Errors which happen while using the API are turned into Python +RuntimeError exceptions. + +To create a guestfs handle you usually have to perform the following +sequence of calls: + +# Create the handle, call add_drive at least once, and possibly +# several times if the guest has multiple block devices: +g = guestfs.GuestFS () +g.add_drive (\"guest.img\") + +# Launch the qemu subprocess and wait for it to become ready: +g.launch () + +# Now you can issue commands, for example: +logvols = g.lvs () + +\"\"\" + +import libguestfsmod + +class GuestFS: + \"\"\"Instances of this class are libguestfs API handles.\"\"\" + + def __init__ (self): + \"\"\"Create a new libguestfs handle.\"\"\" + self._o = libguestfsmod.create () + + def __del__ (self): + libguestfsmod.close (self._o) + +"; + + List.iter ( + fun (name, style, _, flags, _, _, longdesc) -> + pr " def %s " name; + generate_py_call_args ~handle:"self" (snd style); + pr ":\n"; + + if not (List.mem NotInDocs flags) then ( + let doc = replace_str longdesc "C<guestfs_" "C<g." in + let doc = + match fst style with + | RErr | RInt _ | RInt64 _ | RBool _ + | RConstOptString _ | RConstString _ + | RString _ | RBufferOut _ -> doc + | RStringList _ -> + doc ^ "\n\nThis function returns a list of strings." + | RStruct (_, typ) -> + doc ^ sprintf "\n\nThis function returns a dictionary, with keys matching the various fields in the guestfs_%s structure." typ + | RStructList (_, typ) -> + doc ^ sprintf "\n\nThis function returns a list of %ss. Each %s is represented as a dictionary." typ typ + | RHashtable _ -> + doc ^ "\n\nThis function returns a dictionary." in + let doc = + if List.mem ProtocolLimitWarning flags then + doc ^ "\n\n" ^ protocol_limit_warning + else doc in + let doc = + if List.mem DangerWillRobinson flags then + doc ^ "\n\n" ^ danger_will_robinson + else doc in + let doc = + match deprecation_notice flags with + | None -> doc + | Some txt -> doc ^ "\n\n" ^ txt in + let doc = pod2text ~width:60 name doc in + let doc = List.map (fun line -> replace_str line "\\" "\\\\") doc in + let doc = String.concat "\n " doc in + pr " u\"\"\"%s\"\"\"\n" doc; + ); + pr " return libguestfsmod.%s " name; + generate_py_call_args ~handle:"self._o" (snd style); + pr "\n"; + pr "\n"; + ) all_functions + +(* Generate Python call arguments, eg "(handle, foo, bar)" *) +and generate_py_call_args ~handle args = + pr "(%s" handle; + List.iter (fun arg -> pr ", %s" (name_of_argt arg)) args; + pr ")" |