From 17beae299d5e6bb511c453d0b9d0d7ef906b3d14 Mon Sep 17 00:00:00 2001 From: Eelco Dolstra Date: Fri, 8 Jan 2021 12:51:19 +0100 Subject: [PATCH] Support binary unit prefixes in command line arguments --- src/libmain/shared.cc | 6 ++---- src/libmain/shared.hh | 17 +---------------- src/libutil/args.hh | 5 +---- src/libutil/util.hh | 28 +++++++++++++++++++++++++--- 4 files changed, 29 insertions(+), 27 deletions(-) diff --git a/src/libmain/shared.cc b/src/libmain/shared.cc index f1feeddd6..e797c2fb9 100644 --- a/src/libmain/shared.cc +++ b/src/libmain/shared.cc @@ -219,10 +219,8 @@ LegacyArgs::LegacyArgs(const std::string & programName, .description = description, .labels = {"n"}, .handler = {[=](std::string s) { - if (auto n = string2Int(s)) - settings.set(dest, std::to_string(*n)); - else - throw UsageError("'%s' is not an integer", s); + auto n = string2IntWithUnitPrefix(s); + settings.set(dest, std::to_string(n)); }} }); }; diff --git a/src/libmain/shared.hh b/src/libmain/shared.hh index 38f627b44..edc7b5efa 100644 --- a/src/libmain/shared.hh +++ b/src/libmain/shared.hh @@ -57,22 +57,7 @@ template N getIntArg(const string & opt, { ++i; if (i == end) throw UsageError("'%1%' requires an argument", opt); - string s = *i; - N multiplier = 1; - if (allowUnit && !s.empty()) { - char u = std::toupper(*s.rbegin()); - if (std::isalpha(u)) { - if (u == 'K') multiplier = 1ULL << 10; - else if (u == 'M') multiplier = 1ULL << 20; - else if (u == 'G') multiplier = 1ULL << 30; - else if (u == 'T') multiplier = 1ULL << 40; - else throw UsageError("invalid unit specifier '%1%'", u); - s.resize(s.size() - 1); - } - } - if (auto n = string2Int(s)) - return *n * multiplier; - throw UsageError("'%1%' requires an integer argument", opt); + return string2IntWithUnitPrefix(*i); } diff --git a/src/libutil/args.hh b/src/libutil/args.hh index 823d843aa..3783bc84f 100644 --- a/src/libutil/args.hh +++ b/src/libutil/args.hh @@ -87,10 +87,7 @@ protected: template Handler(I * dest) : fun([=](std::vector ss) { - if (auto n = string2Int(ss[0])) - *dest = *n; - else - throw UsageError("'%s' is not an integer", ss[0]); + *dest = string2IntWithUnitPrefix(ss[0]); }) , arity(1) { } diff --git a/src/libutil/util.hh b/src/libutil/util.hh index 7a4d5fe92..ab0bd865a 100644 --- a/src/libutil/util.hh +++ b/src/libutil/util.hh @@ -401,12 +401,34 @@ template std::optional string2Int(const std::string & s) { if (s.substr(0, 1) == "-" && !std::numeric_limits::is_signed) - return {}; + return std::nullopt; std::istringstream str(s); N n; str >> n; if (str && str.get() == EOF) return n; - return {}; + return std::nullopt; +} + +/* Like string2Int(), but support an optional suffix 'K', 'M', 'G' or + 'T' denoting a binary unit prefix. */ +template +N string2IntWithUnitPrefix(std::string s) +{ + N multiplier = 1; + if (!s.empty()) { + char u = std::toupper(*s.rbegin()); + if (std::isalpha(u)) { + if (u == 'K') multiplier = 1ULL << 10; + else if (u == 'M') multiplier = 1ULL << 20; + else if (u == 'G') multiplier = 1ULL << 30; + else if (u == 'T') multiplier = 1ULL << 40; + else throw UsageError("invalid unit specifier '%1%'", u); + s.resize(s.size() - 1); + } + } + if (auto n = string2Int(s)) + return *n * multiplier; + throw UsageError("'%s' is not an integer", s); } /* Parse a string into a float. */ @@ -417,7 +439,7 @@ std::optional string2Float(const string & s) N n; str >> n; if (str && str.get() == EOF) return n; - return {}; + return std::nullopt; }