mirror of
https://github.com/matrix-construct/construct
synced 2024-12-26 15:33:54 +01:00
ircd::rfc1459: Output grammar [part 2: protocol-safe format strings].
This commit is contained in:
Jason Volk
parent
1e2ce3617d
commit
1837f55d11
2 changed files with 307 additions and 0 deletions
|
|
@ -188,6 +188,45 @@ std::ostream &operator<<(std::ostream &, const cmd &);
|
|||
std::ostream &operator<<(std::ostream &, const parv &);
|
||||
std::ostream &operator<<(std::ostream &, const line &); // unterminated
|
||||
|
||||
namespace fmt
|
||||
{
|
||||
IRCD_EXCEPTION(rfc1459::error, error);
|
||||
IRCD_EXCEPTION(error, fmtstr_invalid);
|
||||
IRCD_EXCEPTION(error, fmtstr_mismatch);
|
||||
|
||||
struct spec;
|
||||
|
||||
// internal API
|
||||
using ptrs = std::vector<const void *>;
|
||||
using types = std::vector<std::type_index>;
|
||||
using arg = std::tuple<const void *const &, const std::type_index &>;
|
||||
using handler = std::function<bool (char *&, const size_t &, const spec &, const arg &)>;
|
||||
ssize_t _snprintf(char *const &, const size_t &, const char *const &, const ptrs &, const types &);
|
||||
|
||||
// public API
|
||||
template<class... Args> ssize_t snprintf(char *const &buf, const size_t &max, const char *const &fmt, Args&&... args);
|
||||
}
|
||||
|
||||
|
||||
template<class... Args>
|
||||
ssize_t
|
||||
fmt::snprintf(char *const &buf,
|
||||
const size_t &max,
|
||||
const char *const &fmt,
|
||||
Args&&... args)
|
||||
{
|
||||
static const std::vector<std::type_index> types
|
||||
{
|
||||
typeid(Args)...
|
||||
};
|
||||
|
||||
const std::vector<const void *> ptrs
|
||||
{
|
||||
std::addressof(args)...
|
||||
};
|
||||
|
||||
return _snprintf(buf, max, fmt, ptrs, types);
|
||||
}
|
||||
|
||||
inline bool
|
||||
less::operator()(const std::string *const &a,
|
||||
|
|
|
|||
268
ircd/rfc1459.cc
268
ircd/rfc1459.cc
|
|
@ -340,6 +340,274 @@ rfc1459::gen::grammar<it, top>::grammar(karma::rule<it, top> &top_rule)
|
|||
{
|
||||
}
|
||||
|
||||
namespace ircd {
|
||||
namespace rfc1459 {
|
||||
namespace fmt {
|
||||
|
||||
const char SPECIFIER
|
||||
{
|
||||
'%'
|
||||
};
|
||||
|
||||
struct spec
|
||||
{
|
||||
char sign;
|
||||
int width;
|
||||
std::string name;
|
||||
|
||||
spec(): sign('+'), width(0)
|
||||
{
|
||||
name.reserve(14);
|
||||
}
|
||||
};
|
||||
|
||||
template<class generator> bool generate_string(char *&out, const generator &, const arg &);
|
||||
bool handle_nick(char *&out, const size_t &max, const spec &, const arg &);
|
||||
bool handle_user(char *&out, const size_t &max, const spec &, const arg &);
|
||||
bool handle_host(char *&out, const size_t &max, const spec &, const arg &);
|
||||
void handle_specifier(char *&out, const size_t &max, const spec &, const arg &);
|
||||
bool is_specifier(const std::string &name);
|
||||
|
||||
std::map<std::string, handler> handlers
|
||||
{
|
||||
{ "nick", handle_nick },
|
||||
{ "user", handle_user },
|
||||
{ "host", handle_host },
|
||||
};
|
||||
|
||||
|
||||
} // namespace fmt
|
||||
} // namespace rfc1459
|
||||
} // namespace ircd
|
||||
|
||||
BOOST_FUSION_ADAPT_STRUCT
|
||||
(
|
||||
ircd::rfc1459::fmt::spec,
|
||||
( char, sign )
|
||||
( int, width )
|
||||
( std::string, name )
|
||||
)
|
||||
|
||||
bool
|
||||
rfc1459::fmt::is_specifier(const std::string &name)
|
||||
{
|
||||
return handlers.count(name);
|
||||
}
|
||||
|
||||
void
|
||||
rfc1459::fmt::handle_specifier(char *&out,
|
||||
const size_t &max,
|
||||
const spec &spec,
|
||||
const arg &val)
|
||||
try
|
||||
{
|
||||
const auto &type(get<1>(val));
|
||||
const auto &handler(handlers.at(spec.name));
|
||||
if(!handler(out, max, spec, val))
|
||||
throw fmtstr_mismatch("Invalid type `%s' for format specifier '%c%s'",
|
||||
type.name(),
|
||||
SPECIFIER,
|
||||
spec.name.c_str());
|
||||
}
|
||||
catch(const std::out_of_range &e)
|
||||
{
|
||||
throw fmtstr_invalid("Unhandled specifier `%s' in format string",
|
||||
spec.name.c_str());
|
||||
}
|
||||
|
||||
bool
|
||||
rfc1459::fmt::handle_host(char *&out,
|
||||
const size_t &max,
|
||||
const spec &spec,
|
||||
const arg &val)
|
||||
{
|
||||
using karma::eps;
|
||||
using karma::maxwidth;
|
||||
|
||||
struct generator
|
||||
:gen::grammar<char *, std::string()>
|
||||
{
|
||||
generator(): grammar{grammar::user} {}
|
||||
}
|
||||
static const generator;
|
||||
const auto gen(maxwidth(max)[generator] | eps);
|
||||
return generate_string(out, gen, val);
|
||||
}
|
||||
|
||||
bool
|
||||
rfc1459::fmt::handle_nick(char *&out,
|
||||
const size_t &max,
|
||||
const spec &spec,
|
||||
const arg &val)
|
||||
{
|
||||
using karma::eps;
|
||||
using karma::maxwidth;
|
||||
|
||||
struct generator
|
||||
:gen::grammar<char *, std::string()>
|
||||
{
|
||||
generator(): grammar{grammar::nick} {}
|
||||
}
|
||||
static const generator;
|
||||
const auto gen(maxwidth(max)[generator] | eps);
|
||||
return generate_string(out, gen, val);
|
||||
}
|
||||
|
||||
bool
|
||||
rfc1459::fmt::handle_user(char *&out,
|
||||
const size_t &max,
|
||||
const spec &spec,
|
||||
const arg &val)
|
||||
{
|
||||
using karma::eps;
|
||||
using karma::maxwidth;
|
||||
|
||||
struct generator
|
||||
:gen::grammar<char *, std::string()>
|
||||
{
|
||||
generator(): grammar{grammar::user} {}
|
||||
}
|
||||
static const generator;
|
||||
const auto gen(maxwidth(max)[generator] | eps);
|
||||
return generate_string(out, gen, val);
|
||||
}
|
||||
|
||||
template<class generator>
|
||||
bool
|
||||
rfc1459::fmt::generate_string(char *&out,
|
||||
const generator &gen,
|
||||
const arg &val)
|
||||
{
|
||||
const auto &ptr(get<0>(val));
|
||||
const auto &type(get<1>(val));
|
||||
if(type == typeid(std::string))
|
||||
{
|
||||
const auto &str(*reinterpret_cast<const std::string *>(ptr));
|
||||
karma::generate(out, gen, str);
|
||||
return true;
|
||||
}
|
||||
else if(type == typeid(const char *))
|
||||
{
|
||||
const auto &str(reinterpret_cast<const char *>(ptr));
|
||||
karma::generate(out, gen, str);
|
||||
return true;
|
||||
}
|
||||
else return false;
|
||||
}
|
||||
|
||||
namespace ircd {
|
||||
namespace rfc1459 {
|
||||
namespace fmt {
|
||||
|
||||
using qi::lit;
|
||||
using qi::char_;
|
||||
using qi::int_;
|
||||
using qi::eps;
|
||||
using qi::repeat;
|
||||
using qi::omit;
|
||||
|
||||
template<class it,
|
||||
class top>
|
||||
struct grammar
|
||||
:qi::grammar<it, top>
|
||||
{
|
||||
qi::rule<it> specsym;
|
||||
qi::rule<it, std::string()> name;
|
||||
qi::rule<it, fmt::spec> spec;
|
||||
|
||||
grammar(qi::rule<it, top> &top_rule);
|
||||
};
|
||||
|
||||
struct parse_specifier
|
||||
:fmt::grammar<const char *, fmt::spec>
|
||||
{
|
||||
parse_specifier(): grammar{grammar::spec} {}
|
||||
}
|
||||
static const parse_specifier;
|
||||
|
||||
} // namespace fmt
|
||||
} // namespace rfc1459
|
||||
} // namespace ircd
|
||||
|
||||
template<class it,
|
||||
class top>
|
||||
rfc1459::fmt::grammar<it, top>::grammar(qi::rule<it, top> &top_rule)
|
||||
:grammar<it, top>::base_type
|
||||
{
|
||||
top_rule
|
||||
}
|
||||
,specsym
|
||||
{
|
||||
lit(SPECIFIER)
|
||||
}
|
||||
,name
|
||||
{
|
||||
repeat(1,14)[char_("A-Za-z")]
|
||||
}
|
||||
{
|
||||
spec %= specsym >> -char_("+-") >> -int_ >> name[([]
|
||||
(auto &str, auto &ctx, auto &valid)
|
||||
{
|
||||
valid = is_specifier(str);
|
||||
})];
|
||||
}
|
||||
|
||||
ssize_t
|
||||
rfc1459::fmt::_snprintf(char *const &buf,
|
||||
const size_t &max,
|
||||
const char *const &fmt,
|
||||
const std::vector<const void *> &p,
|
||||
const std::vector<std::type_index> &t)
|
||||
try
|
||||
{
|
||||
if(unlikely(!max))
|
||||
return 0;
|
||||
|
||||
char *out(buf); // Always points at next place to write
|
||||
const char *stop(fmt); // Saves the 'last' place to copy a literal from
|
||||
const char *start(strchr(fmt, SPECIFIER)); // The running position of the format string parse
|
||||
const char *const end(fmt + strlen(fmt)); // The end of the format string
|
||||
|
||||
// Copies string data between format specifiers.
|
||||
const auto copy_literal([&stop, &buf, &out, &max]
|
||||
(const char *const &end)
|
||||
{
|
||||
const size_t rem(max - std::distance(buf, out) - 1);
|
||||
const size_t len(std::distance(stop, end));
|
||||
const size_t &cpsz(std::min(len, rem));
|
||||
memcpy(out, stop, cpsz);
|
||||
out += cpsz;
|
||||
});
|
||||
|
||||
size_t index(0); // The current position for vectors p and t (specifier count)
|
||||
for(; start && start != end; stop = start++, start = strchr(start, SPECIFIER))
|
||||
{
|
||||
// Copy literal data from where the last parse stopped up to the found specifier
|
||||
copy_literal(start);
|
||||
|
||||
// Parse the specifier with the grammar
|
||||
fmt::spec spec;
|
||||
if(!qi::parse(start, end, fmt::parse_specifier, spec))
|
||||
continue;
|
||||
|
||||
// Throws if the format string has more specifiers than arguments.
|
||||
const auto rem(max - std::distance(buf, out) - 1);
|
||||
handle_specifier(out, rem, spec, { p.at(index), t.at(index) });
|
||||
index++;
|
||||
}
|
||||
|
||||
// If the end of the string is not a format specifier itself, it needs to be copied
|
||||
if(!start)
|
||||
copy_literal(end);
|
||||
|
||||
*out = '\0';
|
||||
return std::distance(buf, out);
|
||||
}
|
||||
catch(const std::out_of_range &e)
|
||||
{
|
||||
throw fmtstr_invalid("Format string requires more than %zu arguments.", p.size());
|
||||
}
|
||||
|
||||
//NOTE: unterminated
|
||||
//TODO: Fix carriage
|
||||
std::ostream &
|
||||
|
|
|
|||
Loading…
Reference in a new issue