Patch #923098: Share interned strings in marshal.
diff --git a/Doc/api/utilities.tex b/Doc/api/utilities.tex
index f4fa899..bfcfe27 100644
--- a/Doc/api/utilities.tex
+++ b/Doc/api/utilities.tex
@@ -283,20 +283,31 @@
Numeric values are stored with the least significant byte first.
-\begin{cfuncdesc}{void}{PyMarshal_WriteLongToFile}{long value, FILE *file}
+The module supports two versions of the data format: version 0 is the
+historical version, version 1 (new in Python 2.4) shares interned
+strings in the file, and upon unmarshalling. \var{Py_MARSHAL_VERSION}
+indicates the current file format (currently 1).
+
+\begin{cfuncdesc}{void}{PyMarshal_WriteLongToFile}{long value, FILE *file, int version}
Marshal a \ctype{long} integer, \var{value}, to \var{file}. This
will only write the least-significant 32 bits of \var{value};
regardless of the size of the native \ctype{long} type.
+
+ \versionchanged[\var{version} indicates the file format]{2.4}
\end{cfuncdesc}
\begin{cfuncdesc}{void}{PyMarshal_WriteObjectToFile}{PyObject *value,
- FILE *file}
+ FILE *file, int version}
Marshal a Python object, \var{value}, to \var{file}.
+
+ \versionchanged[\var{version} indicates the file format]{2.4}
\end{cfuncdesc}
-\begin{cfuncdesc}{PyObject*}{PyMarshal_WriteObjectToString}{PyObject *value}
+\begin{cfuncdesc}{PyObject*}{PyMarshal_WriteObjectToString}{PyObject *value, int version}
Return a string object containing the marshalled representation of
\var{value}.
+
+ \versionchanged[\var{version} indicates the file format]{2.4}
\end{cfuncdesc}
The following functions allow marshalled values to be read back in.
diff --git a/Doc/lib/libmarshal.tex b/Doc/lib/libmarshal.tex
index f597e84..53ca668 100644
--- a/Doc/lib/libmarshal.tex
+++ b/Doc/lib/libmarshal.tex
@@ -73,6 +73,9 @@
a \exception{ValueError} exception is raised --- but garbage data
will also be written to the file. The object will not be properly
read back by \function{load()}.
+
+ \versionadded[The \var{version} argument indicates the data
+ format that \code{dumps} should use.]{2.4}
\end{funcdesc}
\begin{funcdesc}{load}{file}
@@ -86,11 +89,14 @@
\code{None} for the unmarshallable type.}
\end{funcdesc}
-\begin{funcdesc}{dumps}{value}
+\begin{funcdesc}{dumps}{value\optional{, version}}
Return the string that would be written to a file by
\code{dump(\var{value}, \var{file})}. The value must be a supported
type. Raise a \exception{ValueError} exception if value has (or
contains an object that has) an unsupported type.
+
+ \versionadded[The \var{version} argument indicates the data
+ format that \code{dumps} should use.]{2.4}
\end{funcdesc}
\begin{funcdesc}{loads}{string}
@@ -98,3 +104,13 @@
\exception{EOFError}, \exception{ValueError} or
\exception{TypeError}. Extra characters in the string are ignored.
\end{funcdesc}
+
+In addition, the following constants are defined:
+
+\begin{datadesc}{version}
+ Indicates the format that the module uses. Version 0 is the
+ historical format, version 1 (added in Python 2.4) shares
+ interned strings. The current version is 1.
+
+ \versionadded{2.4}
+\end{datadesc}
\ No newline at end of file
diff --git a/Include/marshal.h b/Include/marshal.h
index f123093..fc491dd 100644
--- a/Include/marshal.h
+++ b/Include/marshal.h
@@ -7,9 +7,11 @@
extern "C" {
#endif
-PyAPI_FUNC(void) PyMarshal_WriteLongToFile(long, FILE *);
-PyAPI_FUNC(void) PyMarshal_WriteObjectToFile(PyObject *, FILE *);
-PyAPI_FUNC(PyObject *) PyMarshal_WriteObjectToString(PyObject *);
+#define Py_MARSHAL_VERSION 1
+
+PyAPI_FUNC(void) PyMarshal_WriteLongToFile(long, FILE *, int);
+PyAPI_FUNC(void) PyMarshal_WriteObjectToFile(PyObject *, FILE *, int);
+PyAPI_FUNC(PyObject *) PyMarshal_WriteObjectToString(PyObject *, int);
PyAPI_FUNC(long) PyMarshal_ReadLongFromFile(FILE *);
PyAPI_FUNC(int) PyMarshal_ReadShortFromFile(FILE *);
diff --git a/Misc/NEWS b/Misc/NEWS
index f24adc5..41a79c8 100644
--- a/Misc/NEWS
+++ b/Misc/NEWS
@@ -12,6 +12,9 @@
Core and builtins
-----------------
+- marshal now shares interned strings. This change introduces
+ a new .pyc magic.
+
- Bug #966623. classes created with type() in an exec(, {}) don't
have a __module__, but code in typeobject assumed it would always
be there.
diff --git a/Python/import.c b/Python/import.c
index d4c9e2e..e76ada9 100644
--- a/Python/import.c
+++ b/Python/import.c
@@ -26,9 +26,9 @@
a .pyc file in text mode the magic number will be wrong; also, the
Apple MPW compiler swaps their values, botching string constants.
- Apparently, there was a distinction made between even and odd
- bytecodes that is related to Unicode. The details aren't clear,
- but the magic number has been odd for a long time.
+ The magic numbers must be spaced apart atleast 2 values, as the
+ -U interpeter flag will cause MAGIC+1 being used. They have been
+ odd numbers for some time now.
There were a variety of old schemes for setting the magic number.
The current working scheme is to increment the previous value by
@@ -47,9 +47,9 @@
Python 2.3a0: 62011
Python 2.3a0: 62021
Python 2.3a0: 62011 (!)
- Python 2.4a0: 62031
+ Python 2.4a0: 62041
*/
-#define MAGIC (62031 | ((long)'\r'<<16) | ((long)'\n'<<24))
+#define MAGIC (62041 | ((long)'\r'<<16) | ((long)'\n'<<24))
/* Magic word as global; note that _PyImport_Init() can change the
value of this global to accommodate for alterations of how the
@@ -797,10 +797,10 @@
"# can't create %s\n", cpathname);
return;
}
- PyMarshal_WriteLongToFile(pyc_magic, fp);
+ PyMarshal_WriteLongToFile(pyc_magic, fp, Py_MARSHAL_VERSION);
/* First write a 0 for mtime */
- PyMarshal_WriteLongToFile(0L, fp);
- PyMarshal_WriteObjectToFile((PyObject *)co, fp);
+ PyMarshal_WriteLongToFile(0L, fp, Py_MARSHAL_VERSION);
+ PyMarshal_WriteObjectToFile((PyObject *)co, fp, Py_MARSHAL_VERSION);
if (fflush(fp) != 0 || ferror(fp)) {
if (Py_VerboseFlag)
PySys_WriteStderr("# can't write %s\n", cpathname);
@@ -811,7 +811,7 @@
}
/* Now write the true mtime */
fseek(fp, 4L, 0);
- PyMarshal_WriteLongToFile(mtime, fp);
+ PyMarshal_WriteLongToFile(mtime, fp, Py_MARSHAL_VERSION);
fflush(fp);
fclose(fp);
if (Py_VerboseFlag)
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);
}