diff options
Diffstat (limited to 'Python/marshal.c')
| -rw-r--r-- | Python/marshal.c | 47 |
1 files changed, 47 insertions, 0 deletions
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 @@ PyMarshal_ReadLongFromFile(FILE *fp) 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 * |