Mercurial > minori
annotate src/sys/x11/settings.cc @ 364:99c961c91809
core: refactor out byte stream into its own file
easy dubs
| author | Paper <paper@paper.us.eu.org> |
|---|---|
| date | Tue, 16 Jul 2024 21:15:59 -0400 |
| parents | 9aaf1e788896 |
| children |
| rev | line source |
|---|---|
| 351 | 1 #include "sys/x11/settings.h" |
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2 #include "core/byte_stream.h" |
| 351 | 3 |
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4 #include <cassert> |
| 351 | 5 #include <cstring> |
| 6 #include <cstdint> | |
| 7 #include <climits> | |
| 8 #include <string_view> | |
| 9 #include <memory> | |
| 10 #include <array> | |
| 11 #include <optional> | |
| 12 #include <map> | |
| 13 | |
| 14 #include <xcb/xcb.h> | |
| 15 | |
| 16 #include "fmt/core.h" | |
| 17 | |
| 18 namespace x11 { | |
| 19 | |
| 20 bool SettingsItem::VerifyType() { | |
| 21 switch (type) { | |
| 22 case SettingsItem::TypeInt: | |
| 23 case SettingsItem::TypeStr: | |
| 24 case SettingsItem::TypeRgba: | |
| 25 return true; | |
| 26 default: | |
| 27 return false; | |
| 28 } | |
| 29 } | |
| 30 | |
| 31 /* -------------------------------------------------------------------------- */ | |
| 32 /* xsettings parser */ | |
| 33 | |
| 34 static constexpr std::size_t GetPadding(std::size_t length, std::size_t increment) { | |
| 35 /* ripped from xsettingsd */ | |
| 36 return (increment - (length % increment)) % increment; | |
| 37 } | |
| 38 | |
| 39 class Parser { | |
| 40 public: | |
| 41 Parser(std::uint8_t *bytes, std::size_t size); | |
| 42 | |
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43 bool ParseHeader(void); |
| 351 | 44 std::optional<SettingsItem> ParseNextItem(void); |
| 45 | |
| 46 std::uint32_t GetTotalItems(void); | |
| 47 | |
| 48 private: | |
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49 enum ByteOrder { |
| 351 | 50 LSBFirst = 0, |
| 51 MSBFirst = 1, | |
| 52 }; | |
| 53 | |
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54 ByteStream stream; |
| 351 | 55 |
| 56 /* parsed in the constructor */ | |
| 57 std::uint32_t serial_ = 0; | |
| 58 std::uint32_t total_items_ = 0; | |
| 59 }; | |
| 60 | |
| 61 std::uint32_t Parser::GetTotalItems(void) { | |
| 62 return total_items_; | |
| 63 } | |
| 64 | |
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65 Parser::Parser(std::uint8_t *bytes, std::size_t size) : stream(bytes, size) { |
| 351 | 66 } |
| 67 | |
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68 bool Parser::ParseHeader(void) { |
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69 std::uint8_t byte_order; |
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70 if (!stream.ReadBinary<std::uint8_t>(byte_order)) |
| 351 | 71 return false; |
| 72 | |
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73 switch (byte_order) { |
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74 case MSBFirst: |
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75 stream.SetEndianness(ByteStream::ByteOrder::Big); |
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76 break; |
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77 case LSBFirst: |
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78 stream.SetEndianness(ByteStream::ByteOrder::Little); |
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79 break; |
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80 default: |
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81 return false; /* errr */ |
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82 } |
| 351 | 83 |
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84 stream.Advance(3); |
| 351 | 85 |
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86 if (!stream.ReadInt<std::uint32_t>(serial_)) |
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87 return false; |
| 351 | 88 |
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89 if (!stream.ReadInt<std::uint32_t>(total_items_)) |
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90 return false; |
| 351 | 91 |
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92 return true; |
| 351 | 93 } |
| 94 | |
| 95 std::optional<SettingsItem> Parser::ParseNextItem(void) { | |
| 96 SettingsItem item; | |
| 97 | |
| 98 /* read one byte */ | |
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99 if (!stream.ReadInt<std::uint8_t>(item.type)) |
| 351 | 100 return std::nullopt; |
| 101 | |
| 102 if (!item.VerifyType()) | |
| 103 return std::nullopt; | |
| 104 | |
| 105 /* skip padding */ | |
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106 if (!stream.Advance(1)) |
| 351 | 107 return std::nullopt; |
| 108 | |
| 109 /* parse the name */ | |
| 110 std::uint16_t name_size; | |
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111 if (!stream.ReadInt<std::uint16_t>(name_size)) |
| 351 | 112 return std::nullopt; |
| 113 | |
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114 if (!stream.ReadString(item.name, name_size)) |
| 351 | 115 return std::nullopt; |
| 116 | |
| 117 /* padding */ | |
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118 if (!stream.Advance(GetPadding(name_size, 4))) |
| 351 | 119 return std::nullopt; |
| 120 | |
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121 if (!stream.ReadInt<std::uint32_t>(item.serial)) |
| 351 | 122 return std::nullopt; |
| 123 | |
| 124 switch (item.type) { | |
| 125 case SettingsItem::TypeInt: { | |
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126 if (!stream.ReadInt<std::int32_t>(item.data.integer)) |
| 351 | 127 return std::nullopt; |
| 128 | |
| 129 break; | |
| 130 } | |
| 131 case SettingsItem::TypeStr: { | |
| 132 std::uint32_t size; | |
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133 if (!stream.ReadInt<std::uint32_t>(size)) |
| 351 | 134 return std::nullopt; |
| 135 | |
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136 if (!stream.ReadString(item.data.string, size)) |
| 351 | 137 return std::nullopt; |
| 138 | |
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139 /* don't fail if advancing fails on this padding, |
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140 * because this causes parsing to fail for strings |
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141 * at the end of the data */ |
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142 stream.Advance(GetPadding(size, 4)); |
| 351 | 143 |
| 144 break; | |
| 145 } | |
| 146 case SettingsItem::TypeRgba: { | |
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147 /* it's actually RBGA, but whatever. */ |
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148 if (!stream.ReadInt<std::uint16_t>(item.data.rgba.red) |
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149 || !stream.ReadInt<std::uint16_t>(item.data.rgba.blue) |
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150 || !stream.ReadInt<std::uint16_t>(item.data.rgba.green) |
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151 || !stream.ReadInt<std::uint16_t>(item.data.rgba.alpha)) |
| 351 | 152 return std::nullopt; |
| 153 | |
| 154 break; | |
| 155 } | |
| 156 default: | |
| 157 /* can't do anything now, can we? */ | |
| 158 return std::nullopt; | |
| 159 } | |
| 160 | |
| 161 return item; | |
| 162 } | |
| 163 | |
| 164 /* ------------------------------------------------------------------------- */ | |
| 165 /* real X11 code */ | |
| 166 | |
| 167 template<typename T> | |
| 168 struct MallocDestructor { | |
| 169 void operator()(T *t) const { std::free(t); }; | |
| 170 }; | |
| 171 | |
| 172 struct XcbConnectionDestructor { | |
| 173 void operator()(xcb_connection_t *conn) const { ::xcb_disconnect(conn); }; | |
| 174 }; | |
| 175 | |
| 176 template<typename T> | |
| 177 using MallocPtr = std::unique_ptr<T, MallocDestructor<T>>; | |
| 178 | |
| 179 using XcbConnectionPtr = std::unique_ptr<xcb_connection_t, XcbConnectionDestructor>; | |
| 180 | |
| 181 /* RAII is nice */ | |
| 182 struct XcbGrabber { | |
| 183 XcbGrabber(::xcb_connection_t *conn) { ::xcb_grab_server(conn); conn_ = conn; } | |
| 184 ~XcbGrabber() { ::xcb_ungrab_server(conn_); } | |
| 185 | |
| 186 private: | |
| 187 ::xcb_connection_t *conn_; | |
| 188 }; | |
| 189 | |
| 190 static ::xcb_window_t GetSelectionOwner(::xcb_connection_t *conn, ::xcb_atom_t selection) { | |
| 191 ::xcb_window_t owner = XCB_NONE; | |
| 192 MallocPtr<::xcb_get_selection_owner_reply_t> reply(::xcb_get_selection_owner_reply(conn, ::xcb_get_selection_owner(conn, selection), nullptr)); | |
| 193 | |
| 194 if (reply) | |
| 195 owner = reply->owner; | |
| 196 | |
| 197 return owner; | |
| 198 } | |
| 199 | |
| 200 static bool GetRawSettingsData(std::vector<uint8_t>& bytes) { | |
| 201 int screen; | |
| 202 | |
| 203 XcbConnectionPtr conn(::xcb_connect(nullptr, &screen)); | |
| 204 if (::xcb_connection_has_error(conn.get())) | |
| 205 return false; | |
| 206 | |
| 207 /* get our needed atoms, available as atoms[Atom] */ | |
| 208 enum Atom { | |
| 209 XSETTINGS_SCREEN, /* _XSETTINGS_S[N] */ | |
| 210 XSETTINGS_SETTINGS, /* _XSETTINGS_SETTINGS */ | |
| 211 }; | |
| 212 | |
| 213 std::map<Atom, ::xcb_atom_t> atoms; | |
| 214 { | |
| 215 std::map<Atom, std::string> names = { | |
| 216 {XSETTINGS_SCREEN, fmt::format("_XSETTINGS_S{}", screen)}, | |
| 217 {XSETTINGS_SETTINGS, "_XSETTINGS_SETTINGS"}, | |
| 218 }; | |
| 219 | |
| 220 std::map<Atom, ::xcb_intern_atom_cookie_t> atom_cookies; | |
| 221 for (const auto& name : names) | |
| 222 atom_cookies[name.first] = ::xcb_intern_atom(conn.get(), false, name.second.size(), name.second.data()); | |
| 223 | |
| 224 for (const auto& cookie : atom_cookies) { | |
| 225 MallocPtr<::xcb_intern_atom_reply_t> reply(::xcb_intern_atom_reply(conn.get(), cookie.second, nullptr)); | |
| 226 if (!reply || reply->atom == XCB_NONE) | |
| 227 return false; | |
| 228 | |
| 229 atoms[cookie.first] = reply->atom; | |
| 230 } | |
| 231 } | |
| 232 | |
| 233 MallocPtr<xcb_get_property_reply_t> reply; | |
| 234 { | |
| 235 /* grab the X server as *required* by xsettings docs */ | |
| 236 const XcbGrabber grabber(conn.get()); | |
| 237 | |
| 238 ::xcb_window_t win = GetSelectionOwner(conn.get(), atoms[XSETTINGS_SCREEN]); | |
| 239 if (win == XCB_NONE) | |
| 240 return false; | |
| 241 | |
| 242 reply.reset(::xcb_get_property_reply(conn.get(), ::xcb_get_property(conn.get(), 0, win, atoms[XSETTINGS_SETTINGS], XCB_ATOM_ANY, 0L, UINT_MAX), nullptr)); | |
| 243 }; | |
| 244 if (!reply) | |
| 245 return false; | |
| 246 | |
| 247 uint8_t *data = reinterpret_cast<uint8_t *>(xcb_get_property_value(reply.get())); | |
| 248 int size = xcb_get_property_value_length(reply.get()); | |
| 249 if (size < 0) | |
| 250 return false; | |
| 251 | |
| 252 bytes.assign(data, data + size); | |
| 253 | |
| 254 return true; | |
| 255 } | |
| 256 | |
| 257 /* ------------------------------------------------------------------------- */ | |
| 258 /* now for the actual all-important public API stringing all this together */ | |
| 259 | |
| 260 bool GetSettings(std::vector<SettingsItem>& settings) { | |
| 261 std::vector<std::uint8_t> xsettings_raw; | |
| 262 if (!GetRawSettingsData(xsettings_raw)) | |
| 263 return false; | |
| 264 | |
| 265 Parser parser(xsettings_raw.data(), xsettings_raw.size()); | |
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266 if (!parser.ParseHeader()) |
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267 return false; |
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268 |
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269 std::uint32_t total = parser.GetTotalItems(); |
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270 |
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271 while (total--) { |
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272 std::optional<SettingsItem> opt_item = parser.ParseNextItem(); |
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273 if (!opt_item) |
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274 break; |
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275 |
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276 settings.push_back(opt_item.value()); |
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277 } |
| 351 | 278 |
| 279 return true; | |
| 280 } | |
| 281 | |
| 282 bool FindSetting(const std::string& name, SettingsItem& setting) { | |
| 283 std::vector<std::uint8_t> xsettings_raw; | |
| 284 if (!GetRawSettingsData(xsettings_raw)) | |
| 285 return false; | |
| 286 | |
| 287 Parser parser(xsettings_raw.data(), xsettings_raw.size()); | |
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288 if (!parser.ParseHeader()) |
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289 return false; |
| 351 | 290 |
| 291 std::uint32_t total = parser.GetTotalItems(); | |
| 292 | |
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293 while (total--) { |
| 351 | 294 std::optional<SettingsItem> opt_item = parser.ParseNextItem(); |
| 295 if (!opt_item) | |
| 296 return false; | |
| 297 | |
| 298 SettingsItem& item = opt_item.value(); | |
| 299 if (item.name == name) { | |
| 300 setting = item; | |
| 301 return true; | |
| 302 } | |
| 303 } | |
| 304 | |
| 305 return false; | |
| 306 } | |
| 307 | |
| 308 } // namespace x11 |