Variant of SF patch 103252: Startup optimize: read *.pyc as string, not with getc().
diff --git a/Misc/ACKS b/Misc/ACKS
index 6c90fd4..2a15aed 100644
--- a/Misc/ACKS
+++ b/Misc/ACKS
@@ -179,6 +179,7 @@
Jeremy Hylton
John Interrante
Ben Jackson
+Paul Jackson
Jack Jansen
Bill Janssen
Drew Jenkins
diff --git a/Python/marshal.c b/Python/marshal.c
index a9b3ed1..684a8b4 100644
--- a/Python/marshal.c
+++ b/Python/marshal.c
@@ -606,16 +606,63 @@
return r_long(&rf);
}
+#ifdef HAVE_FSTAT
+/* Return size of file in bytes; < 0 if unknown. */
+static off_t
+getfilesize(FILE *fp)
+{
+ struct stat st;
+ if (fstat(fileno(fp), &st) != 0)
+ return -1;
+ else
+ return st.st_size;
+}
+#endif
+
+/* If we can get the size of the file up-front, and it's reasonably small,
+ * read it in one gulp and delegate to ...FromString() instead. Much quicker
+ * than reading a byte at a time from file; speeds .pyc imports.
+ */
PyObject *
PyMarshal_ReadObjectFromFile(FILE *fp)
{
+/* 75% of 2.1's .pyc files can exploit SMALL_FILE_LIMIT.
+ * REASONABLE_FILE_LIMIT is by defn something big enough for Tkinter.pyc.
+ */
+#define SMALL_FILE_LIMIT (1L << 14)
+#define REASONABLE_FILE_LIMIT (1L << 18)
RFILE rf;
+#ifdef HAVE_FSTAT
+ off_t filesize;
+#endif
if (PyErr_Occurred()) {
fprintf(stderr, "XXX rd_object called with exception set\n");
return NULL;
}
+#ifdef HAVE_FSTAT
+ filesize = getfilesize(fp);
+ if (filesize > 0) {
+ char buf[SMALL_FILE_LIMIT];
+ char* pBuf = NULL;
+ if (filesize <= SMALL_FILE_LIMIT)
+ pBuf = buf;
+ else if (filesize <= REASONABLE_FILE_LIMIT)
+ pBuf = (char *)PyMem_MALLOC(filesize);
+ if (pBuf != NULL) {
+ PyObject* v;
+ size_t n = fread(pBuf, 1, filesize, fp);
+ v = PyMarshal_ReadObjectFromString(pBuf, n);
+ if (pBuf != buf)
+ PyMem_FREE(pBuf);
+ return v;
+ }
+
+ }
+#endif
rf.fp = fp;
return r_object(&rf);
+#undef SMALL_FILE_LIMIT
+#undef REASONABLE_FILE_LIMIT
}
PyObject *