diff options
author | Tor Lillqvist <tml@collabora.com> | 2015-01-20 16:24:14 +0200 |
---|---|---|
committer | Michael Meeks <michael.meeks@collabora.com> | 2015-01-21 07:21:19 +0000 |
commit | dad7161cc30b335a108c7850f453877a161969ae (patch) | |
tree | b0b093ffe95b869a94fe3de283e33baff7254c4c /formula | |
parent | cd5f69376bf27275d92073943451b8b72a708d04 (diff) |
fdo88632: Make the Calc random functions non-random when requested
We don't want such a mode to affect other uses of randomness, though. Thus use
a separate random number generator object for these two functions, and use a
fixed seed for it if the SC_RAND_REPEATABLE environment variable is set.
As RAND() is implemented in sc, and RANDBETWEEN() is implemented in scaddins,
it was a bit hard to figure out where to add the new functions needed, without
having to over-engineer things with UNO. (This functionality is totally
Calc-specific, but neither sc nor scaddins has any public (non-UNO) API.)
Caolan suggested the formula module, which seems like a good enough place to
me.
Change-Id: Ic1c9ca165278d53036598b03b13b4ffbdc98a75e
Reviewed-on: https://gerrit.libreoffice.org/14053
Reviewed-by: Michael Meeks <michael.meeks@collabora.com>
Tested-by: Michael Meeks <michael.meeks@collabora.com>
Diffstat (limited to 'formula')
-rw-r--r-- | formula/Library_for.mk | 1 | ||||
-rw-r--r-- | formula/README | 6 | ||||
-rw-r--r-- | formula/source/core/api/random.cxx | 56 |
3 files changed, 61 insertions, 2 deletions
diff --git a/formula/Library_for.mk b/formula/Library_for.mk index d2a6671d3b20..85cf5e8d2036 100644 --- a/formula/Library_for.mk +++ b/formula/Library_for.mk @@ -41,6 +41,7 @@ $(eval $(call gb_Library_set_componentfile,for,formula/util/for)) $(eval $(call gb_Library_add_exception_objects,for,\ formula/source/core/api/FormulaCompiler \ formula/source/core/api/FormulaOpCodeMapperObj \ + formula/source/core/api/random \ formula/source/core/api/services \ formula/source/core/api/token \ formula/source/core/api/vectortoken \ diff --git a/formula/README b/formula/README index da0d528c1cad..ab2c28a08c42 100644 --- a/formula/README +++ b/formula/README @@ -1,3 +1,5 @@ -Contains parts of the formula parser used outside Calc code. +Contains parts of the formula parser used outside Calc code that has +been pulled out from Calc's formula parser code. -Has been pulled out from Calc's formula parser code. +Also contains some functions that are needed by code in both sc and +scaddins. Located here just for convenience. So sue me. diff --git a/formula/source/core/api/random.cxx b/formula/source/core/api/random.cxx new file mode 100644 index 000000000000..727262fdffd5 --- /dev/null +++ b/formula/source/core/api/random.cxx @@ -0,0 +1,56 @@ +/* -*- Mode: C++; tab-width: 4; indent-tabs-mode: nil; c-basic-offset: 4 -*- */ +/* + * This file is part of the LibreOffice project. + * + * This Source Code Form is subject to the terms of the Mozilla Public + * License, v. 2.0. If a copy of the MPL was not distributed with this + * file, You can obtain one at http://mozilla.org/MPL/2.0/. + */ + +#include <time.h> + +#include <random> + +#include <formula/random.hxx> +#include <rtl/instance.hxx> + +namespace { + +struct CalcFormulaRandomGenerator +{ + std::mt19937 aRng; + CalcFormulaRandomGenerator() + { + // initialises the state of this RNG. + // should only be called once. + bool bRepeatable = (getenv("SC_RAND_REPEATABLE") != 0); + aRng.seed(bRepeatable ? 42 : time(NULL)); + } +}; + +class theCalcFormulaRandomGenerator : public rtl::Static<CalcFormulaRandomGenerator, theCalcFormulaRandomGenerator> {}; + +} + +namespace formula +{ + +namespace rng +{ + +double fRandom(double a, double b) +{ + std::uniform_real_distribution<double> dist(a, b); + return dist(theCalcFormulaRandomGenerator::get().aRng); +} + +sal_Int32 nRandom(sal_Int32 a, sal_Int32 b) +{ + std::uniform_int_distribution<sal_Int32> dist(a, b); + return dist(theCalcFormulaRandomGenerator::get().aRng); +} + +} // rng +} // formula + +/* vim:set shiftwidth=4 softtabstop=4 expandtab: */ |