From 1d138f1c1a37a630099b629cf42c0bbe46d1344b Mon Sep 17 00:00:00 2001 From: Eric Smith Date: Sat, 31 May 2008 01:40:08 +0000 Subject: [PATCH] Optimization of str.format() for cases with unicode, long, and float arguments. This gives about 30% speed improvement for the simplest (but most common) cases. This patch skips the __format__ dispatch, and also avoids creating an object to hold the format_spec. Unfortunately, backporting this to 2.6 is going to be more challenging due to str/unicode issues with format_spec. I'll work on that next. Then I'll spend some time profiling and see what that tells me. --- Objects/stringlib/string_format.h | 33 +++++++++++++++++++++++++------ 1 file changed, 27 insertions(+), 6 deletions(-) diff --git a/Objects/stringlib/string_format.h b/Objects/stringlib/string_format.h index 2e9c7efd4c1..7e62af575fe 100644 --- a/Objects/stringlib/string_format.h +++ b/Objects/stringlib/string_format.h @@ -483,13 +483,34 @@ render_field(PyObject *fieldobj, SubString *format_spec, OutputString *output) { int ok = 0; PyObject *result = NULL; + PyObject *format_spec_object = NULL; - /* we need to create an object out of the pointers we have */ - PyObject *format_spec_object = SubString_new_object_or_empty(format_spec); - if (format_spec_object == NULL) - goto done; + STRINGLIB_CHAR* format_spec_start = format_spec->ptr ? + format_spec->ptr : NULL; + Py_ssize_t format_spec_len = format_spec->ptr ? + format_spec->end - format_spec->ptr : 0; - result = PyObject_Format(fieldobj, format_spec_object); + /* If we know the type exactly, skip the lookup of __format__ and just + call the formatter directly. */ + if (PyUnicode_CheckExact(fieldobj)) + result = _PyUnicode_FormatAdvanced(fieldobj, format_spec_start, + format_spec_len); + else if (PyLong_CheckExact(fieldobj)) + result = _PyLong_FormatAdvanced(fieldobj, format_spec_start, + format_spec_len); + else if (PyFloat_CheckExact(fieldobj)) + result = _PyFloat_FormatAdvanced(fieldobj, format_spec_start, + format_spec_len); + else { + /* We need to create an object out of the pointers we have, because + __format__ takes a string/unicode object for format_spec. */ + format_spec_object = STRINGLIB_NEW(format_spec_start, + format_spec_len); + if (format_spec_object == NULL) + goto done; + + result = PyObject_Format(fieldobj, format_spec_object); + } if (result == NULL) goto done; @@ -512,7 +533,7 @@ render_field(PyObject *fieldobj, SubString *format_spec, OutputString *output) ok = output_data(output, STRINGLIB_STR(result), STRINGLIB_LEN(result)); done: - Py_DECREF(format_spec_object); + Py_XDECREF(format_spec_object); Py_XDECREF(result); return ok; }