diff options
| -rw-r--r-- | Objects/fileobject.c | 29 |
1 files changed, 16 insertions, 13 deletions
diff --git a/Objects/fileobject.c b/Objects/fileobject.c index 6a82cce..ebe0d29 100644 --- a/Objects/fileobject.c +++ b/Objects/fileobject.c @@ -937,19 +937,21 @@ get_line(PyFileObject *f, int n) FILE *fp = f->f_fp; int c; char *buf, *end; - size_t n1, n2; + size_t total_v_size; /* total # of slots in buffer */ + size_t used_v_size; /* # used slots in buffer */ + size_t increment; /* amount to increment the buffer */ PyObject *v; #ifdef USE_FGETS_IN_GETLINE if (n <= 0) return getline_via_fgets(fp); #endif - n2 = n > 0 ? n : 100; - v = PyString_FromStringAndSize((char *)NULL, n2); + total_v_size = n > 0 ? n : 100; + v = PyString_FromStringAndSize((char *)NULL, total_v_size); if (v == NULL) return NULL; buf = BUF(v); - end = buf + n2; + end = buf + total_v_size; for (;;) { Py_BEGIN_ALLOW_THREADS @@ -979,23 +981,24 @@ get_line(PyFileObject *f, int n) /* Must be because buf == end */ if (n > 0) break; - n1 = n2; - n2 += 1000; - if (n2 > INT_MAX) { + used_v_size = total_v_size; + increment = total_v_size >> 2; /* mild exponential growth */ + total_v_size += increment; + if (total_v_size > INT_MAX) { PyErr_SetString(PyExc_OverflowError, "line is longer than a Python string can hold"); Py_DECREF(v); return NULL; } - if (_PyString_Resize(&v, n2) < 0) + if (_PyString_Resize(&v, total_v_size) < 0) return NULL; - buf = BUF(v) + n1; - end = BUF(v) + n2; + buf = BUF(v) + used_v_size; + end = BUF(v) + total_v_size; } - n1 = buf - BUF(v); - if (n1 != n2) - _PyString_Resize(&v, n1); + used_v_size = buf - BUF(v); + if (used_v_size != total_v_size) + _PyString_Resize(&v, used_v_size); return v; } |