diff options
| -rw-r--r-- | Include/bytesobject.h | 1 | ||||
| -rw-r--r-- | Objects/bytesobject.c | 64 |
2 files changed, 54 insertions, 11 deletions
diff --git a/Include/bytesobject.h b/Include/bytesobject.h index 72ca076..849078d 100644 --- a/Include/bytesobject.h +++ b/Include/bytesobject.h @@ -21,6 +21,7 @@ extern "C" { /* Object layout */ typedef struct { PyObject_VAR_HEAD + Py_ssize_t ob_alloc; /* How many bytes allocated */ char *ob_bytes; } PyBytesObject; diff --git a/Objects/bytesobject.c b/Objects/bytesobject.c index c4f9eec..d1ebc16 100644 --- a/Objects/bytesobject.c +++ b/Objects/bytesobject.c @@ -4,6 +4,7 @@ #define PY_SSIZE_T_CLEAN #include "Python.h" +#include "structmember.h" /* Direct API functions */ @@ -25,7 +26,6 @@ PyBytes_FromStringAndSize(const char *bytes, Py_ssize_t size) if (new == NULL) return NULL; - new->ob_size = size; if (size == 0) new->ob_bytes = NULL; else { @@ -37,6 +37,7 @@ PyBytes_FromStringAndSize(const char *bytes, Py_ssize_t size) if (bytes != NULL) memcpy(new->ob_bytes, bytes, size); } + new->ob_size = new->ob_alloc = size; return (PyObject *)new; } @@ -63,12 +64,31 @@ int PyBytes_Resize(PyObject *self, Py_ssize_t size) { void *sval; + Py_ssize_t alloc = ((PyBytesObject *)self)->ob_alloc; assert(self != NULL); assert(PyBytes_Check(self)); assert(size >= 0); - sval = PyMem_Realloc(((PyBytesObject *)self)->ob_bytes, size); + if (size < alloc / 2) { + /* Major downsize; resize down to exact size */ + alloc = size; + } + else if (size <= alloc) { + /* Within allocated size; quick exit */ + ((PyBytesObject *)self)->ob_size = size; + return 0; + } + else if (size <= alloc * 1.125) { + /* Moderate upsize; overallocate similar to list_resize() */ + alloc = size + (size >> 3) + (size < 9 ? 3 : 6); + } + else { + /* Major upsize; resize up to exact size */ + alloc = size; + } + + sval = PyMem_Realloc(((PyBytesObject *)self)->ob_bytes, alloc); if (sval == NULL) { PyErr_NoMemory(); return -1; @@ -76,6 +96,7 @@ PyBytes_Resize(PyObject *self, Py_ssize_t size) ((PyBytesObject *)self)->ob_bytes = sval; ((PyBytesObject *)self)->ob_size = size; + ((PyBytesObject *)self)->ob_alloc = alloc; return 0; } @@ -133,7 +154,9 @@ bytes_iconcat(PyBytesObject *self, PyObject *other) size = mysize + osize; if (size < 0) return PyErr_NoMemory(); - if (PyBytes_Resize((PyObject *)self, size) < 0) + if (size <= self->ob_alloc) + self->ob_size = size; + else if (PyBytes_Resize((PyObject *)self, size) < 0) return NULL; memcpy(self->ob_bytes + mysize, ((PyBytesObject *)other)->ob_bytes, osize); Py_INCREF(self); @@ -178,7 +201,9 @@ bytes_irepeat(PyBytesObject *self, Py_ssize_t count) size = mysize * count; if (count != 0 && size / count != mysize) return PyErr_NoMemory(); - if (PyBytes_Resize((PyObject *)self, size) < 0) + if (size <= self->ob_alloc) + self->ob_size = size; + else if (PyBytes_Resize((PyObject *)self, size) < 0) return NULL; if (mysize == 1) @@ -372,9 +397,11 @@ bytes_init(PyBytesObject *self, PyObject *args, PyObject *kwds) PyObject *it; PyObject *(*iternext)(PyObject *); - /* Empty previous contents (yes, do this first of all!) */ - if (PyBytes_Resize((PyObject *)self, 0) < 0) - return -1; + if (self->ob_size != 0) { + /* Empty previous contents (yes, do this first of all!) */ + if (PyBytes_Resize((PyObject *)self, 0) < 0) + return -1; + } /* Parse arguments */ if (!PyArg_ParseTupleAndKeywords(args, kwds, "|Oss:bytes", kwlist, @@ -410,7 +437,9 @@ bytes_init(PyBytesObject *self, PyObject *args, PyObject *kwds) } bytes = PyString_AS_STRING(encoded); size = PyString_GET_SIZE(encoded); - if (PyBytes_Resize((PyObject *)self, size) < 0) { + if (size <= self->ob_alloc) + self->ob_size = size; + else if (PyBytes_Resize((PyObject *)self, size) < 0) { Py_DECREF(encoded); return -1; } @@ -492,8 +521,9 @@ bytes_init(PyBytesObject *self, PyObject *args, PyObject *kwds) } /* Append the byte */ - /* XXX Speed this up */ - if (PyBytes_Resize((PyObject *)self, self->ob_size+1) < 0) + if (self->ob_size < self->ob_alloc) + self->ob_size++; + else if (PyBytes_Resize((PyObject *)self, self->ob_size+1) < 0) goto error; self->ob_bytes[self->ob_size-1] = value; } @@ -673,6 +703,17 @@ bytes_decode(PyObject *self, PyObject *args) return PyCodec_Decode(self, encoding, errors); } +PyDoc_STRVAR(alloc_doc, +"B.__alloc__() -> int\n\ +\n\ +Returns the number of bytes actually allocated."); + +static PyObject * +bytes_alloc(PyBytesObject *self) +{ + return PyInt_FromSsize_t(self->ob_alloc); +} + static PySequenceMethods bytes_as_sequence = { (lenfunc)bytes_length, /*sq_length*/ (binaryfunc)bytes_concat, /*sq_concat*/ @@ -704,7 +745,8 @@ static PyBufferProcs bytes_as_buffer = { static PyMethodDef bytes_methods[] = { {"decode", (PyCFunction)bytes_decode, METH_VARARGS, decode_doc}, - {NULL, NULL} + {"__alloc__", (PyCFunction)bytes_alloc, METH_NOARGS, alloc_doc}, + {NULL} }; PyDoc_STRVAR(bytes_doc, |