Sort string subcommands, and use binary search for lookup

I have no idea if this is better, and did not attempt to measure it, but we
do the same for electric variables which are even fewer.
This commit is contained in:
Johannes Altmanninger 2020-09-27 21:33:23 +02:00
parent 30f821c8f4
commit 5ae03414d7

View file

@ -1131,13 +1131,14 @@ bool regex_replacer_t::replace_matches(const wcstring &arg) {
if (!regex.code) return false; // pcre2_compile() failed
if (!replacement) return false; // replacement was an invalid string
// clang-format off
// SUBSTITUTE_OVERFLOW_LENGTH causes pcre to return the needed buffer length if the passed one is to small
// SUBSTITUTE_EXTENDED changes how substitution expressions are interpreted (`$` as the special character)
// SUBSTITUTE_UNSET_EMPTY treats unmatched capturing groups as empty instead of erroring.
// SUBSTITUTE_GLOBAL means more than one substitution happens.
// clang-format on
uint32_t options = PCRE2_SUBSTITUTE_OVERFLOW_LENGTH | PCRE2_SUBSTITUTE_EXTENDED |
PCRE2_SUBSTITUTE_UNSET_EMPTY |
(opts.all ? PCRE2_SUBSTITUTE_GLOBAL : 0);
PCRE2_SUBSTITUTE_UNSET_EMPTY | (opts.all ? PCRE2_SUBSTITUTE_GLOBAL : 0);
size_t arglen = arg.length();
PCRE2_SIZE bufsize = (arglen == 0) ? 16 : 2 * arglen;
auto output = static_cast<wchar_t *>(malloc(sizeof(wchar_t) * bufsize));
@ -1521,20 +1522,19 @@ static int string_upper(parser_t &parser, io_streams_t &streams, int argc, wchar
return string_transform(parser, streams, argc, argv, std::towupper);
}
// Keep sorted alphabetically
static const struct string_subcommand {
const wchar_t *name;
int (*handler)(parser_t &, io_streams_t &, int argc, //!OCLINT(unused param)
wchar_t **argv); //!OCLINT(unused param)
}
string_subcommands[] = {
{L"escape", &string_escape}, {L"join", &string_join}, {L"join0", &string_join0},
{L"length", &string_length}, {L"match", &string_match}, {L"replace", &string_replace},
{L"split", &string_split}, {L"split0", &string_split0}, {L"sub", &string_sub},
{L"trim", &string_trim}, {L"lower", &string_lower}, {L"upper", &string_upper},
{L"repeat", &string_repeat}, {L"unescape", &string_unescape}, {L"collect", &string_collect},
{L"pad", &string_pad},
{nullptr, nullptr}};
} string_subcommands[] = {
{L"collect", &string_collect}, {L"escape", &string_escape}, {L"join", &string_join},
{L"join0", &string_join0}, {L"length", &string_length}, {L"lower", &string_lower},
{L"match", &string_match}, {L"pad", &string_pad}, {L"repeat", &string_repeat},
{L"replace", &string_replace}, {L"split", &string_split}, {L"split0", &string_split0},
{L"sub", &string_sub}, {L"trim", &string_trim}, {L"unescape", &string_unescape},
{L"upper", &string_upper},
};
/// The string builtin, for manipulating strings.
maybe_t<int> builtin_string(parser_t &parser, io_streams_t &streams, wchar_t **argv) {
@ -1551,18 +1551,26 @@ maybe_t<int> builtin_string(parser_t &parser, io_streams_t &streams, wchar_t **a
return STATUS_CMD_OK;
}
const string_subcommand *subcmd = &string_subcommands[0];
while (subcmd->name != nullptr && std::wcscmp(subcmd->name, argv[1]) != 0) {
subcmd++;
}
if (!subcmd->handler) {
streams.err.append_format(BUILTIN_ERR_INVALID_SUBCMD, cmd, argv[1]);
const wchar_t *subcmd_name = argv[1];
static auto begin = std::begin(string_subcommands);
static auto end = std::end(string_subcommands);
string_subcommand search{subcmd_name, 0};
auto binsearch = std::lower_bound(
begin, end, search, [&](const string_subcommand &cmd1, const string_subcommand &cmd2) {
return wcscmp(cmd1.name, cmd2.name) < 0;
});
const string_subcommand *subcmd = nullptr;
if (binsearch != end && wcscmp(subcmd_name, binsearch->name) == 0) subcmd = &*binsearch;
if (subcmd == nullptr) {
streams.err.append_format(BUILTIN_ERR_INVALID_SUBCMD, cmd, subcmd_name);
builtin_print_error_trailer(parser, streams.err, L"string");
return STATUS_INVALID_ARGS;
}
if (argc >= 3 && (std::wcscmp(argv[2], L"-h") == 0 || std::wcscmp(argv[2], L"--help") == 0)) {
wcstring string_dash_subcommand = wcstring(argv[0]) + L"-" + argv[1];
wcstring string_dash_subcommand = wcstring(argv[0]) + L"-" + subcmd_name;
builtin_print_help(parser, streams, string_dash_subcommand.c_str());
return STATUS_CMD_OK;
}