Daniel P. Berrange | 666a3af | 2015-02-27 16:19:33 +0000 | [diff] [blame] | 1 | /* |
| 2 | * QEMU I/O channels |
| 3 | * |
| 4 | * Copyright (c) 2015 Red Hat, Inc. |
| 5 | * |
| 6 | * This library is free software; you can redistribute it and/or |
| 7 | * modify it under the terms of the GNU Lesser General Public |
| 8 | * License as published by the Free Software Foundation; either |
| 9 | * version 2 of the License, or (at your option) any later version. |
| 10 | * |
| 11 | * This library is distributed in the hope that it will be useful, |
| 12 | * but WITHOUT ANY WARRANTY; without even the implied warranty of |
| 13 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU |
| 14 | * Lesser General Public License for more details. |
| 15 | * |
| 16 | * You should have received a copy of the GNU Lesser General Public |
| 17 | * License along with this library; if not, see <http://www.gnu.org/licenses/>. |
| 18 | * |
| 19 | */ |
| 20 | |
| 21 | #ifndef QIO_CHANNEL_H__ |
| 22 | #define QIO_CHANNEL_H__ |
| 23 | |
| 24 | #include "qemu-common.h" |
Daniel P. Berrange | 666a3af | 2015-02-27 16:19:33 +0000 | [diff] [blame] | 25 | #include "qom/object.h" |
| 26 | |
| 27 | #define TYPE_QIO_CHANNEL "qio-channel" |
| 28 | #define QIO_CHANNEL(obj) \ |
| 29 | OBJECT_CHECK(QIOChannel, (obj), TYPE_QIO_CHANNEL) |
| 30 | #define QIO_CHANNEL_CLASS(klass) \ |
| 31 | OBJECT_CLASS_CHECK(QIOChannelClass, klass, TYPE_QIO_CHANNEL) |
| 32 | #define QIO_CHANNEL_GET_CLASS(obj) \ |
| 33 | OBJECT_GET_CLASS(QIOChannelClass, obj, TYPE_QIO_CHANNEL) |
| 34 | |
| 35 | typedef struct QIOChannel QIOChannel; |
| 36 | typedef struct QIOChannelClass QIOChannelClass; |
| 37 | |
| 38 | #define QIO_CHANNEL_ERR_BLOCK -2 |
| 39 | |
| 40 | typedef enum QIOChannelFeature QIOChannelFeature; |
| 41 | |
| 42 | enum QIOChannelFeature { |
| 43 | QIO_CHANNEL_FEATURE_FD_PASS = (1 << 0), |
| 44 | QIO_CHANNEL_FEATURE_SHUTDOWN = (1 << 1), |
Marc-André Lureau | 3fa27a9 | 2016-06-16 21:28:51 +0200 | [diff] [blame^] | 45 | QIO_CHANNEL_FEATURE_LISTEN = (1 << 2), |
Daniel P. Berrange | 666a3af | 2015-02-27 16:19:33 +0000 | [diff] [blame] | 46 | }; |
| 47 | |
| 48 | |
| 49 | typedef enum QIOChannelShutdown QIOChannelShutdown; |
| 50 | |
| 51 | enum QIOChannelShutdown { |
| 52 | QIO_CHANNEL_SHUTDOWN_BOTH, |
| 53 | QIO_CHANNEL_SHUTDOWN_READ, |
| 54 | QIO_CHANNEL_SHUTDOWN_WRITE, |
| 55 | }; |
| 56 | |
| 57 | typedef gboolean (*QIOChannelFunc)(QIOChannel *ioc, |
| 58 | GIOCondition condition, |
| 59 | gpointer data); |
| 60 | |
| 61 | /** |
| 62 | * QIOChannel: |
| 63 | * |
| 64 | * The QIOChannel defines the core API for a generic I/O channel |
| 65 | * class hierarchy. It is inspired by GIOChannel, but has the |
| 66 | * following differences |
| 67 | * |
| 68 | * - Use QOM to properly support arbitrary subclassing |
| 69 | * - Support use of iovecs for efficient I/O with multiple blocks |
| 70 | * - None of the character set translation, binary data exclusively |
| 71 | * - Direct support for QEMU Error object reporting |
| 72 | * - File descriptor passing |
| 73 | * |
| 74 | * This base class is abstract so cannot be instantiated. There |
| 75 | * will be subclasses for dealing with sockets, files, and higher |
| 76 | * level protocols such as TLS, WebSocket, etc. |
| 77 | */ |
| 78 | |
| 79 | struct QIOChannel { |
| 80 | Object parent; |
| 81 | unsigned int features; /* bitmask of QIOChannelFeatures */ |
Paolo Bonzini | a589720 | 2016-03-07 12:12:36 +0100 | [diff] [blame] | 82 | #ifdef _WIN32 |
| 83 | HANDLE event; /* For use with GSource on Win32 */ |
| 84 | #endif |
Daniel P. Berrange | 666a3af | 2015-02-27 16:19:33 +0000 | [diff] [blame] | 85 | }; |
| 86 | |
| 87 | /** |
| 88 | * QIOChannelClass: |
| 89 | * |
| 90 | * This class defines the contract that all subclasses |
| 91 | * must follow to provide specific channel implementations. |
| 92 | * The first five callbacks are mandatory to support, others |
| 93 | * provide additional optional features. |
| 94 | * |
| 95 | * Consult the corresponding public API docs for a description |
| 96 | * of the semantics of each callback |
| 97 | */ |
| 98 | struct QIOChannelClass { |
| 99 | ObjectClass parent; |
| 100 | |
| 101 | /* Mandatory callbacks */ |
| 102 | ssize_t (*io_writev)(QIOChannel *ioc, |
| 103 | const struct iovec *iov, |
| 104 | size_t niov, |
| 105 | int *fds, |
| 106 | size_t nfds, |
| 107 | Error **errp); |
| 108 | ssize_t (*io_readv)(QIOChannel *ioc, |
| 109 | const struct iovec *iov, |
| 110 | size_t niov, |
| 111 | int **fds, |
| 112 | size_t *nfds, |
| 113 | Error **errp); |
| 114 | int (*io_close)(QIOChannel *ioc, |
| 115 | Error **errp); |
| 116 | GSource * (*io_create_watch)(QIOChannel *ioc, |
| 117 | GIOCondition condition); |
| 118 | int (*io_set_blocking)(QIOChannel *ioc, |
| 119 | bool enabled, |
| 120 | Error **errp); |
| 121 | |
| 122 | /* Optional callbacks */ |
| 123 | int (*io_shutdown)(QIOChannel *ioc, |
| 124 | QIOChannelShutdown how, |
| 125 | Error **errp); |
| 126 | void (*io_set_cork)(QIOChannel *ioc, |
| 127 | bool enabled); |
| 128 | void (*io_set_delay)(QIOChannel *ioc, |
| 129 | bool enabled); |
| 130 | off_t (*io_seek)(QIOChannel *ioc, |
| 131 | off_t offset, |
| 132 | int whence, |
| 133 | Error **errp); |
| 134 | }; |
| 135 | |
| 136 | /* General I/O handling functions */ |
| 137 | |
| 138 | /** |
| 139 | * qio_channel_has_feature: |
| 140 | * @ioc: the channel object |
| 141 | * @feature: the feature to check support of |
| 142 | * |
| 143 | * Determine whether the channel implementation supports |
| 144 | * the optional feature named in @feature. |
| 145 | * |
| 146 | * Returns: true if supported, false otherwise. |
| 147 | */ |
| 148 | bool qio_channel_has_feature(QIOChannel *ioc, |
| 149 | QIOChannelFeature feature); |
| 150 | |
| 151 | /** |
| 152 | * qio_channel_readv_full: |
| 153 | * @ioc: the channel object |
| 154 | * @iov: the array of memory regions to read data into |
| 155 | * @niov: the length of the @iov array |
| 156 | * @fds: pointer to an array that will received file handles |
| 157 | * @nfds: pointer filled with number of elements in @fds on return |
Daniel P. Berrange | 821791b | 2016-01-13 12:22:33 +0000 | [diff] [blame] | 158 | * @errp: pointer to a NULL-initialized error object |
Daniel P. Berrange | 666a3af | 2015-02-27 16:19:33 +0000 | [diff] [blame] | 159 | * |
| 160 | * Read data from the IO channel, storing it in the |
| 161 | * memory regions referenced by @iov. Each element |
| 162 | * in the @iov will be fully populated with data |
| 163 | * before the next one is used. The @niov parameter |
| 164 | * specifies the total number of elements in @iov. |
| 165 | * |
| 166 | * It is not required for all @iov to be filled with |
| 167 | * data. If the channel is in blocking mode, at least |
| 168 | * one byte of data will be read, but no more is |
| 169 | * guaranteed. If the channel is non-blocking and no |
| 170 | * data is available, it will return QIO_CHANNEL_ERR_BLOCK |
| 171 | * |
| 172 | * If the channel has passed any file descriptors, |
| 173 | * the @fds array pointer will be allocated and |
| 174 | * the elements filled with the received file |
| 175 | * descriptors. The @nfds pointer will be updated |
| 176 | * to indicate the size of the @fds array that |
| 177 | * was allocated. It is the callers responsibility |
| 178 | * to call close() on each file descriptor and to |
| 179 | * call g_free() on the array pointer in @fds. |
| 180 | * |
| 181 | * It is an error to pass a non-NULL @fds parameter |
| 182 | * unless qio_channel_has_feature() returns a true |
| 183 | * value for the QIO_CHANNEL_FEATURE_FD_PASS constant. |
| 184 | * |
| 185 | * Returns: the number of bytes read, or -1 on error, |
| 186 | * or QIO_CHANNEL_ERR_BLOCK if no data is available |
| 187 | * and the channel is non-blocking |
| 188 | */ |
| 189 | ssize_t qio_channel_readv_full(QIOChannel *ioc, |
| 190 | const struct iovec *iov, |
| 191 | size_t niov, |
| 192 | int **fds, |
| 193 | size_t *nfds, |
| 194 | Error **errp); |
| 195 | |
| 196 | |
| 197 | /** |
| 198 | * qio_channel_writev_full: |
| 199 | * @ioc: the channel object |
| 200 | * @iov: the array of memory regions to write data from |
| 201 | * @niov: the length of the @iov array |
| 202 | * @fds: an array of file handles to send |
| 203 | * @nfds: number of file handles in @fds |
Daniel P. Berrange | 821791b | 2016-01-13 12:22:33 +0000 | [diff] [blame] | 204 | * @errp: pointer to a NULL-initialized error object |
Daniel P. Berrange | 666a3af | 2015-02-27 16:19:33 +0000 | [diff] [blame] | 205 | * |
| 206 | * Write data to the IO channel, reading it from the |
| 207 | * memory regions referenced by @iov. Each element |
| 208 | * in the @iov will be fully sent, before the next |
| 209 | * one is used. The @niov parameter specifies the |
| 210 | * total number of elements in @iov. |
| 211 | * |
| 212 | * It is not required for all @iov data to be fully |
| 213 | * sent. If the channel is in blocking mode, at least |
| 214 | * one byte of data will be sent, but no more is |
| 215 | * guaranteed. If the channel is non-blocking and no |
| 216 | * data can be sent, it will return QIO_CHANNEL_ERR_BLOCK |
| 217 | * |
| 218 | * If there are file descriptors to send, the @fds |
| 219 | * array should be non-NULL and provide the handles. |
| 220 | * All file descriptors will be sent if at least one |
| 221 | * byte of data was sent. |
| 222 | * |
| 223 | * It is an error to pass a non-NULL @fds parameter |
| 224 | * unless qio_channel_has_feature() returns a true |
| 225 | * value for the QIO_CHANNEL_FEATURE_FD_PASS constant. |
| 226 | * |
| 227 | * Returns: the number of bytes sent, or -1 on error, |
| 228 | * or QIO_CHANNEL_ERR_BLOCK if no data is can be sent |
| 229 | * and the channel is non-blocking |
| 230 | */ |
| 231 | ssize_t qio_channel_writev_full(QIOChannel *ioc, |
| 232 | const struct iovec *iov, |
| 233 | size_t niov, |
| 234 | int *fds, |
| 235 | size_t nfds, |
| 236 | Error **errp); |
| 237 | |
| 238 | /** |
| 239 | * qio_channel_readv: |
| 240 | * @ioc: the channel object |
| 241 | * @iov: the array of memory regions to read data into |
| 242 | * @niov: the length of the @iov array |
Daniel P. Berrange | 821791b | 2016-01-13 12:22:33 +0000 | [diff] [blame] | 243 | * @errp: pointer to a NULL-initialized error object |
Daniel P. Berrange | 666a3af | 2015-02-27 16:19:33 +0000 | [diff] [blame] | 244 | * |
| 245 | * Behaves as qio_channel_readv_full() but does not support |
| 246 | * receiving of file handles. |
| 247 | */ |
| 248 | ssize_t qio_channel_readv(QIOChannel *ioc, |
| 249 | const struct iovec *iov, |
| 250 | size_t niov, |
| 251 | Error **errp); |
| 252 | |
| 253 | /** |
| 254 | * qio_channel_writev: |
| 255 | * @ioc: the channel object |
| 256 | * @iov: the array of memory regions to write data from |
| 257 | * @niov: the length of the @iov array |
Daniel P. Berrange | 821791b | 2016-01-13 12:22:33 +0000 | [diff] [blame] | 258 | * @errp: pointer to a NULL-initialized error object |
Daniel P. Berrange | 666a3af | 2015-02-27 16:19:33 +0000 | [diff] [blame] | 259 | * |
| 260 | * Behaves as qio_channel_writev_full() but does not support |
| 261 | * sending of file handles. |
| 262 | */ |
| 263 | ssize_t qio_channel_writev(QIOChannel *ioc, |
| 264 | const struct iovec *iov, |
| 265 | size_t niov, |
| 266 | Error **errp); |
| 267 | |
| 268 | /** |
| 269 | * qio_channel_readv: |
| 270 | * @ioc: the channel object |
| 271 | * @buf: the memory region to read data into |
| 272 | * @buflen: the length of @buf |
Daniel P. Berrange | 821791b | 2016-01-13 12:22:33 +0000 | [diff] [blame] | 273 | * @errp: pointer to a NULL-initialized error object |
Daniel P. Berrange | 666a3af | 2015-02-27 16:19:33 +0000 | [diff] [blame] | 274 | * |
| 275 | * Behaves as qio_channel_readv_full() but does not support |
| 276 | * receiving of file handles, and only supports reading into |
| 277 | * a single memory region. |
| 278 | */ |
| 279 | ssize_t qio_channel_read(QIOChannel *ioc, |
| 280 | char *buf, |
| 281 | size_t buflen, |
| 282 | Error **errp); |
| 283 | |
| 284 | /** |
| 285 | * qio_channel_writev: |
| 286 | * @ioc: the channel object |
| 287 | * @buf: the memory regions to send data from |
| 288 | * @buflen: the length of @buf |
Daniel P. Berrange | 821791b | 2016-01-13 12:22:33 +0000 | [diff] [blame] | 289 | * @errp: pointer to a NULL-initialized error object |
Daniel P. Berrange | 666a3af | 2015-02-27 16:19:33 +0000 | [diff] [blame] | 290 | * |
| 291 | * Behaves as qio_channel_writev_full() but does not support |
| 292 | * sending of file handles, and only supports writing from a |
| 293 | * single memory region. |
| 294 | */ |
| 295 | ssize_t qio_channel_write(QIOChannel *ioc, |
| 296 | const char *buf, |
| 297 | size_t buflen, |
| 298 | Error **errp); |
| 299 | |
| 300 | /** |
| 301 | * qio_channel_set_blocking: |
| 302 | * @ioc: the channel object |
| 303 | * @enabled: the blocking flag state |
Daniel P. Berrange | 821791b | 2016-01-13 12:22:33 +0000 | [diff] [blame] | 304 | * @errp: pointer to a NULL-initialized error object |
Daniel P. Berrange | 666a3af | 2015-02-27 16:19:33 +0000 | [diff] [blame] | 305 | * |
| 306 | * If @enabled is true, then the channel is put into |
| 307 | * blocking mode, otherwise it will be non-blocking. |
| 308 | * |
| 309 | * In non-blocking mode, read/write operations may |
| 310 | * return QIO_CHANNEL_ERR_BLOCK if they would otherwise |
| 311 | * block on I/O |
| 312 | */ |
| 313 | int qio_channel_set_blocking(QIOChannel *ioc, |
| 314 | bool enabled, |
| 315 | Error **errp); |
| 316 | |
| 317 | /** |
| 318 | * qio_channel_close: |
| 319 | * @ioc: the channel object |
Daniel P. Berrange | 821791b | 2016-01-13 12:22:33 +0000 | [diff] [blame] | 320 | * @errp: pointer to a NULL-initialized error object |
Daniel P. Berrange | 666a3af | 2015-02-27 16:19:33 +0000 | [diff] [blame] | 321 | * |
| 322 | * Close the channel, flushing any pending I/O |
| 323 | * |
| 324 | * Returns: 0 on success, -1 on error |
| 325 | */ |
| 326 | int qio_channel_close(QIOChannel *ioc, |
| 327 | Error **errp); |
| 328 | |
| 329 | /** |
| 330 | * qio_channel_shutdown: |
| 331 | * @ioc: the channel object |
| 332 | * @how: the direction to shutdown |
Daniel P. Berrange | 821791b | 2016-01-13 12:22:33 +0000 | [diff] [blame] | 333 | * @errp: pointer to a NULL-initialized error object |
Daniel P. Berrange | 666a3af | 2015-02-27 16:19:33 +0000 | [diff] [blame] | 334 | * |
| 335 | * Shutdowns transmission and/or receiving of data |
| 336 | * without closing the underlying transport. |
| 337 | * |
| 338 | * Not all implementations will support this facility, |
| 339 | * so may report an error. To avoid errors, the |
| 340 | * caller may check for the feature flag |
| 341 | * QIO_CHANNEL_FEATURE_SHUTDOWN prior to calling |
| 342 | * this method. |
| 343 | * |
| 344 | * Returns: 0 on success, -1 on error |
| 345 | */ |
| 346 | int qio_channel_shutdown(QIOChannel *ioc, |
| 347 | QIOChannelShutdown how, |
| 348 | Error **errp); |
| 349 | |
| 350 | /** |
| 351 | * qio_channel_set_delay: |
| 352 | * @ioc: the channel object |
| 353 | * @enabled: the new flag state |
| 354 | * |
| 355 | * Controls whether the underlying transport is |
| 356 | * permitted to delay writes in order to merge |
| 357 | * small packets. If @enabled is true, then the |
| 358 | * writes may be delayed in order to opportunistically |
| 359 | * merge small packets into larger ones. If @enabled |
| 360 | * is false, writes are dispatched immediately with |
| 361 | * no delay. |
| 362 | * |
| 363 | * When @enabled is false, applications may wish to |
| 364 | * use the qio_channel_set_cork() method to explicitly |
| 365 | * control write merging. |
| 366 | * |
| 367 | * On channels which are backed by a socket, this |
| 368 | * API corresponds to the inverse of TCP_NODELAY flag, |
| 369 | * controlling whether the Nagle algorithm is active. |
| 370 | * |
| 371 | * This setting is merely a hint, so implementations are |
| 372 | * free to ignore this without it being considered an |
| 373 | * error. |
| 374 | */ |
| 375 | void qio_channel_set_delay(QIOChannel *ioc, |
| 376 | bool enabled); |
| 377 | |
| 378 | /** |
| 379 | * qio_channel_set_cork: |
| 380 | * @ioc: the channel object |
| 381 | * @enabled: the new flag state |
| 382 | * |
| 383 | * Controls whether the underlying transport is |
| 384 | * permitted to dispatch data that is written. |
| 385 | * If @enabled is true, then any data written will |
| 386 | * be queued in local buffers until @enabled is |
| 387 | * set to false once again. |
| 388 | * |
| 389 | * This feature is typically used when the automatic |
| 390 | * write coalescing facility is disabled via the |
| 391 | * qio_channel_set_delay() method. |
| 392 | * |
| 393 | * On channels which are backed by a socket, this |
| 394 | * API corresponds to the TCP_CORK flag. |
| 395 | * |
| 396 | * This setting is merely a hint, so implementations are |
| 397 | * free to ignore this without it being considered an |
| 398 | * error. |
| 399 | */ |
| 400 | void qio_channel_set_cork(QIOChannel *ioc, |
| 401 | bool enabled); |
| 402 | |
| 403 | |
| 404 | /** |
| 405 | * qio_channel_seek: |
| 406 | * @ioc: the channel object |
| 407 | * @offset: the position to seek to, relative to @whence |
| 408 | * @whence: one of the (POSIX) SEEK_* constants listed below |
Daniel P. Berrange | 821791b | 2016-01-13 12:22:33 +0000 | [diff] [blame] | 409 | * @errp: pointer to a NULL-initialized error object |
Daniel P. Berrange | 666a3af | 2015-02-27 16:19:33 +0000 | [diff] [blame] | 410 | * |
| 411 | * Moves the current I/O position within the channel |
| 412 | * @ioc, to be @offset. The value of @offset is |
| 413 | * interpreted relative to @whence: |
| 414 | * |
| 415 | * SEEK_SET - the position is set to @offset bytes |
| 416 | * SEEK_CUR - the position is moved by @offset bytes |
| 417 | * SEEK_END - the position is set to end of the file plus @offset bytes |
| 418 | * |
| 419 | * Not all implementations will support this facility, |
| 420 | * so may report an error. |
| 421 | * |
| 422 | * Returns: the new position on success, (off_t)-1 on failure |
| 423 | */ |
| 424 | off_t qio_channel_io_seek(QIOChannel *ioc, |
| 425 | off_t offset, |
| 426 | int whence, |
| 427 | Error **errp); |
| 428 | |
| 429 | |
| 430 | /** |
| 431 | * qio_channel_create_watch: |
| 432 | * @ioc: the channel object |
| 433 | * @condition: the I/O condition to monitor |
| 434 | * |
| 435 | * Create a new main loop source that is used to watch |
| 436 | * for the I/O condition @condition. Typically the |
| 437 | * qio_channel_add_watch() method would be used instead |
| 438 | * of this, since it directly attaches a callback to |
| 439 | * the source |
| 440 | * |
| 441 | * Returns: the new main loop source. |
| 442 | */ |
| 443 | GSource *qio_channel_create_watch(QIOChannel *ioc, |
| 444 | GIOCondition condition); |
| 445 | |
| 446 | /** |
| 447 | * qio_channel_add_watch: |
| 448 | * @ioc: the channel object |
| 449 | * @condition: the I/O condition to monitor |
| 450 | * @func: callback to invoke when the source becomes ready |
| 451 | * @user_data: opaque data to pass to @func |
| 452 | * @notify: callback to free @user_data |
| 453 | * |
| 454 | * Create a new main loop source that is used to watch |
| 455 | * for the I/O condition @condition. The callback @func |
| 456 | * will be registered against the source, to be invoked |
| 457 | * when the source becomes ready. The optional @user_data |
| 458 | * will be passed to @func when it is invoked. The @notify |
| 459 | * callback will be used to free @user_data when the |
| 460 | * watch is deleted |
| 461 | * |
| 462 | * The returned source ID can be used with g_source_remove() |
| 463 | * to remove and free the source when no longer required. |
| 464 | * Alternatively the @func callback can return a FALSE |
| 465 | * value. |
| 466 | * |
| 467 | * Returns: the source ID |
| 468 | */ |
| 469 | guint qio_channel_add_watch(QIOChannel *ioc, |
| 470 | GIOCondition condition, |
| 471 | QIOChannelFunc func, |
| 472 | gpointer user_data, |
| 473 | GDestroyNotify notify); |
| 474 | |
| 475 | |
| 476 | /** |
| 477 | * qio_channel_yield: |
| 478 | * @ioc: the channel object |
| 479 | * @condition: the I/O condition to wait for |
| 480 | * |
| 481 | * Yields execution from the current coroutine until |
| 482 | * the condition indicated by @condition becomes |
| 483 | * available. |
| 484 | * |
| 485 | * This must only be called from coroutine context |
| 486 | */ |
| 487 | void qio_channel_yield(QIOChannel *ioc, |
| 488 | GIOCondition condition); |
| 489 | |
| 490 | /** |
| 491 | * qio_channel_wait: |
| 492 | * @ioc: the channel object |
| 493 | * @condition: the I/O condition to wait for |
| 494 | * |
| 495 | * Block execution from the current thread until |
| 496 | * the condition indicated by @condition becomes |
| 497 | * available. |
| 498 | * |
| 499 | * This will enter a nested event loop to perform |
| 500 | * the wait. |
| 501 | */ |
| 502 | void qio_channel_wait(QIOChannel *ioc, |
| 503 | GIOCondition condition); |
| 504 | |
| 505 | #endif /* QIO_CHANNEL_H__ */ |