diff options
| -rw-r--r-- | Misc/ACKS | 1 | ||||
| -rw-r--r-- | Misc/NEWS | 3 | ||||
| -rw-r--r-- | Modules/cStringIO.c | 58 |
3 files changed, 22 insertions, 40 deletions
@@ -755,6 +755,7 @@ Peter Stoehr Casper Stoel Michael Stone Ken Stox +Patrick Strawderman Dan Stromberg Daniel Stutzbach Nathan Sullivan @@ -48,6 +48,9 @@ Core and Builtins Library ------- +- Issue #10045: Improved performance when writing after seeking past the + end of the "file" in cStringIO. + - Issue #9948: Fixed problem of losing filename case information. - Issue #9437: Fix building C extensions with non-default LDFLAGS. diff --git a/Modules/cStringIO.c b/Modules/cStringIO.c index 6aa3d5d861..be9ad50ab6 100644 --- a/Modules/cStringIO.c +++ b/Modules/cStringIO.c @@ -339,12 +339,12 @@ IO_iternext(Iobject *self) /* Read-write object methods */ -PyDoc_STRVAR(O_seek__doc__, +PyDoc_STRVAR(IO_seek__doc__, "seek(position) -- set the current position\n" "seek(position, mode) -- mode 0: absolute; 1: relative; 2: relative to EOF"); static PyObject * -O_seek(Oobject *self, PyObject *args) { +IO_seek(Iobject *self, PyObject *args) { Py_ssize_t position; int mode = 0; @@ -359,25 +359,10 @@ O_seek(Oobject *self, PyObject *args) { position += self->pos; } - if (position > self->buf_size) { - char *newbuf; - self->buf_size*=2; - if (self->buf_size <= position) self->buf_size=position+1; - newbuf = (char*) realloc(self->buf,self->buf_size); - if (!newbuf) { - free(self->buf); - self->buf = 0; - self->buf_size=self->pos=0; - return PyErr_NoMemory(); - } - self->buf = newbuf; - } - else if (position < 0) position=0; + if (position < 0) position=0; self->pos=position; - while (--position >= self->string_size) self->buf[position]=0; - Py_INCREF(Py_None); return Py_None; } @@ -414,6 +399,19 @@ O_cwrite(PyObject *self, const char *c, Py_ssize_t l) { oself->buf = newbuf; } + if (oself->string_size < oself->pos) { + /* In case of overseek, pad with null bytes the buffer region between + the end of stream and the current position. + + 0 lo string_size hi + | |<---used--->|<----------available----------->| + | | <--to pad-->|<---to write---> | + 0 buf position + */ + memset(oself->buf + oself->string_size, '\0', + (oself->pos - oself->string_size) * sizeof(char)); + } + memcpy(oself->buf+oself->pos,c,l); assert(oself->pos + l < INT_MAX); @@ -497,12 +495,12 @@ static struct PyMethodDef O_methods[] = { {"readline", (PyCFunction)IO_readline, METH_VARARGS, IO_readline__doc__}, {"readlines", (PyCFunction)IO_readlines,METH_VARARGS, IO_readlines__doc__}, {"reset", (PyCFunction)IO_reset, METH_NOARGS, IO_reset__doc__}, + {"seek", (PyCFunction)IO_seek, METH_VARARGS, IO_seek__doc__}, {"tell", (PyCFunction)IO_tell, METH_NOARGS, IO_tell__doc__}, {"truncate", (PyCFunction)IO_truncate, METH_VARARGS, IO_truncate__doc__}, /* Read-write StringIO specific methods: */ {"close", (PyCFunction)O_close, METH_NOARGS, O_close__doc__}, - {"seek", (PyCFunction)O_seek, METH_VARARGS, O_seek__doc__}, {"write", (PyCFunction)O_write, METH_VARARGS, O_write__doc__}, {"writelines", (PyCFunction)O_writelines, METH_O, O_writelines__doc__}, {NULL, NULL} /* sentinel */ @@ -595,26 +593,6 @@ I_close(Iobject *self, PyObject *unused) { return Py_None; } -static PyObject * -I_seek(Iobject *self, PyObject *args) { - Py_ssize_t position; - int mode = 0; - - if (!IO__opencheck(IOOOBJECT(self))) return NULL; - if (!PyArg_ParseTuple(args, "n|i:seek", &position, &mode)) - return NULL; - - if (mode == 2) position += self->string_size; - else if (mode == 1) position += self->pos; - - if (position < 0) position=0; - - self->pos=position; - - Py_INCREF(Py_None); - return Py_None; -} - static struct PyMethodDef I_methods[] = { /* Common methods: */ {"flush", (PyCFunction)IO_flush, METH_NOARGS, IO_flush__doc__}, @@ -624,12 +602,12 @@ static struct PyMethodDef I_methods[] = { {"readline", (PyCFunction)IO_readline, METH_VARARGS, IO_readline__doc__}, {"readlines", (PyCFunction)IO_readlines,METH_VARARGS, IO_readlines__doc__}, {"reset", (PyCFunction)IO_reset, METH_NOARGS, IO_reset__doc__}, + {"seek", (PyCFunction)IO_seek, METH_VARARGS, IO_seek__doc__}, {"tell", (PyCFunction)IO_tell, METH_NOARGS, IO_tell__doc__}, {"truncate", (PyCFunction)IO_truncate, METH_VARARGS, IO_truncate__doc__}, /* Read-only StringIO specific methods: */ {"close", (PyCFunction)I_close, METH_NOARGS, O_close__doc__}, - {"seek", (PyCFunction)I_seek, METH_VARARGS, O_seek__doc__}, {NULL, NULL} }; |