Patch #923098: Share interned strings in marshal.
diff --git a/Python/marshal.c b/Python/marshal.c
index 901b9c6..590e1ca 100644
--- a/Python/marshal.c
+++ b/Python/marshal.c
@@ -27,6 +27,8 @@
#define TYPE_COMPLEX 'x'
#define TYPE_LONG 'l'
#define TYPE_STRING 's'
+#define TYPE_INTERNED 't'
+#define TYPE_STRINGREF 'R'
#define TYPE_TUPLE '('
#define TYPE_LIST '['
#define TYPE_DICT '{'
@@ -42,6 +44,7 @@
PyObject *str;
char *ptr;
char *end;
+ PyObject *strings; /* dict on marshal, list on unmarshal */
} WFILE;
#define w_byte(c, p) if (((p)->fp)) putc((c), (p)->fp); \
@@ -189,7 +192,24 @@
}
#endif
else if (PyString_Check(v)) {
- w_byte(TYPE_STRING, p);
+ if (p->strings && PyString_CHECK_INTERNED(v)) {
+ PyObject *o = PyDict_GetItem(p->strings, v);
+ if (o) {
+ long w = PyInt_AsLong(o);
+ w_byte(TYPE_STRINGREF, p);
+ w_long(w, p);
+ goto exit;
+ }
+ else {
+ o = PyInt_FromLong(PyDict_Size(p->strings));
+ PyDict_SetItem(p->strings, v, o);
+ Py_DECREF(o);
+ w_byte(TYPE_INTERNED, p);
+ }
+ }
+ else {
+ w_byte(TYPE_STRING, p);
+ }
n = PyString_GET_SIZE(v);
w_long((long)n, p);
w_string(PyString_AS_STRING(v), n, p);
@@ -269,28 +289,32 @@
w_byte(TYPE_UNKNOWN, p);
p->error = 1;
}
-
+ exit:
p->depth--;
}
+/* version currently has no effect for writing longs. */
void
-PyMarshal_WriteLongToFile(long x, FILE *fp)
+PyMarshal_WriteLongToFile(long x, FILE *fp, int version)
{
WFILE wf;
wf.fp = fp;
wf.error = 0;
wf.depth = 0;
+ wf.strings = NULL;
w_long(x, &wf);
}
void
-PyMarshal_WriteObjectToFile(PyObject *x, FILE *fp)
+PyMarshal_WriteObjectToFile(PyObject *x, FILE *fp, int version)
{
WFILE wf;
wf.fp = fp;
wf.error = 0;
wf.depth = 0;
+ wf.strings = (version > 0) ? PyDict_New() : NULL;
w_object(x, &wf);
+ Py_XDECREF(wf.strings);
}
typedef WFILE RFILE; /* Same struct with different invariants */
@@ -491,6 +515,7 @@
}
#endif
+ case TYPE_INTERNED:
case TYPE_STRING:
n = r_long(p);
if (n < 0) {
@@ -506,6 +531,16 @@
"EOF read where object expected");
}
}
+ if (type == TYPE_INTERNED) {
+ PyString_InternInPlace(&v);
+ PyList_Append(p->strings, v);
+ }
+ return v;
+
+ case TYPE_STRINGREF:
+ n = r_long(p);
+ v = PyList_GET_ITEM(p->strings, n);
+ Py_INCREF(v);
return v;
#ifdef Py_USING_UNICODE
@@ -673,6 +708,7 @@
{
RFILE rf;
rf.fp = fp;
+ rf.strings = NULL;
return r_short(&rf);
}
@@ -681,6 +717,7 @@
{
RFILE rf;
rf.fp = fp;
+ rf.strings = NULL;
return r_long(&rf);
}
@@ -747,22 +784,30 @@
PyMarshal_ReadObjectFromFile(FILE *fp)
{
RFILE rf;
+ PyObject *result;
rf.fp = fp;
- return read_object(&rf);
+ rf.strings = PyList_New(0);
+ result = r_object(&rf);
+ Py_DECREF(rf.strings);
+ return result;
}
PyObject *
PyMarshal_ReadObjectFromString(char *str, int len)
{
RFILE rf;
+ PyObject *result;
rf.fp = NULL;
rf.ptr = str;
rf.end = str + len;
- return read_object(&rf);
+ rf.strings = PyList_New(0);
+ result = r_object(&rf);
+ Py_DECREF(rf.strings);
+ return result;
}
PyObject *
-PyMarshal_WriteObjectToString(PyObject *x) /* wrs_object() */
+PyMarshal_WriteObjectToString(PyObject *x, int version)
{
WFILE wf;
wf.fp = NULL;
@@ -773,7 +818,9 @@
wf.end = wf.ptr + PyString_Size(wf.str);
wf.error = 0;
wf.depth = 0;
+ wf.strings = (version > 0) ? PyDict_New() : NULL;
w_object(x, &wf);
+ Py_XDECREF(wf.strings);
if (wf.str != NULL)
_PyString_Resize(&wf.str,
(int) (wf.ptr -
@@ -796,7 +843,8 @@
WFILE wf;
PyObject *x;
PyObject *f;
- if (!PyArg_ParseTuple(args, "OO:dump", &x, &f))
+ int version = Py_MARSHAL_VERSION;
+ if (!PyArg_ParseTuple(args, "OO|i:dump", &x, &f, &version))
return NULL;
if (!PyFile_Check(f)) {
PyErr_SetString(PyExc_TypeError,
@@ -808,7 +856,9 @@
wf.ptr = wf.end = NULL;
wf.error = 0;
wf.depth = 0;
+ wf.strings = (version > 0) ? PyDict_New() : 0;
w_object(x, &wf);
+ Py_XDECREF(wf.strings);
if (wf.error) {
PyErr_SetString(PyExc_ValueError,
(wf.error==1)?"unmarshallable object"
@@ -823,7 +873,7 @@
marshal_load(PyObject *self, PyObject *args)
{
RFILE rf;
- PyObject *f;
+ PyObject *f, *result;
if (!PyArg_ParseTuple(args, "O:load", &f))
return NULL;
if (!PyFile_Check(f)) {
@@ -832,16 +882,20 @@
return NULL;
}
rf.fp = PyFile_AsFile(f);
- return read_object(&rf);
+ rf.strings = PyList_New(0);
+ result = read_object(&rf);
+ Py_DECREF(rf.strings);
+ return result;
}
static PyObject *
marshal_dumps(PyObject *self, PyObject *args)
{
PyObject *x;
- if (!PyArg_ParseTuple(args, "O:dumps", &x))
+ int version = Py_MARSHAL_VERSION;
+ if (!PyArg_ParseTuple(args, "O|i:dumps", &x, version))
return NULL;
- return PyMarshal_WriteObjectToString(x);
+ return PyMarshal_WriteObjectToString(x, version);
}
static PyObject *
@@ -850,12 +904,16 @@
RFILE rf;
char *s;
int n;
- if (!PyArg_ParseTuple(args, "s#:loads", &s, &n))
+ PyObject* result;
+ if (!PyArg_ParseTuple(args, "s#|i:loads", &s, &n))
return NULL;
rf.fp = NULL;
rf.ptr = s;
rf.end = s + n;
- return read_object(&rf);
+ rf.strings = PyList_New(0);
+ result = read_object(&rf);
+ Py_DECREF(rf.strings);
+ return result;
}
static PyMethodDef marshal_methods[] = {
@@ -869,5 +927,6 @@
PyMODINIT_FUNC
PyMarshal_Init(void)
{
- (void) Py_InitModule("marshal", marshal_methods);
+ PyObject *mod = Py_InitModule("marshal", marshal_methods);
+ PyModule_AddIntConstant(mod, "version", Py_MARSHAL_VERSION);
}