diff options
Diffstat (limited to 'include/ruby/io.h')
| -rw-r--r-- | include/ruby/io.h | 992 |
1 files changed, 943 insertions, 49 deletions
diff --git a/include/ruby/io.h b/include/ruby/io.h index a3de95f281..e9dfeda5b1 100644 --- a/include/ruby/io.h +++ b/include/ruby/io.h @@ -20,6 +20,8 @@ #endif #include <errno.h> + +/** @cond INTERNAL_MACRO */ #if defined(HAVE_POLL) # ifdef _AIX # define reqevents events @@ -33,145 +35,1037 @@ # undef revents # endif # define RB_WAITFD_IN POLLIN -# define RB_WAITFD_PRI POLLPRI +# if defined(POLLPRI) +# define RB_WAITFD_PRI POLLPRI +# else +# define RB_WAITFD_PRI 0 +# endif # define RB_WAITFD_OUT POLLOUT #else # define RB_WAITFD_IN 0x001 # define RB_WAITFD_PRI 0x002 # define RB_WAITFD_OUT 0x004 #endif +/** @endcond */ -typedef enum { - RUBY_IO_READABLE = RB_WAITFD_IN, - RUBY_IO_WRITABLE = RB_WAITFD_OUT, - RUBY_IO_PRIORITY = RB_WAITFD_PRI, -} rb_io_event_t; - +#include "ruby/internal/attr/const.h" +#include "ruby/internal/attr/packed_struct.h" +#include "ruby/internal/attr/pure.h" +#include "ruby/internal/attr/noreturn.h" #include "ruby/internal/dllexport.h" +#include "ruby/internal/value.h" + +// IO#wait, IO#wait_readable, IO#wait_writable, IO#wait_priority are defined by this implementation. +#define RUBY_IO_WAIT_METHODS + +// Used as the default timeout argument to `rb_io_wait` to use the `IO#timeout` value. +#define RUBY_IO_TIMEOUT_DEFAULT Qnil + RBIMPL_SYMBOL_EXPORT_BEGIN() -PACKED_STRUCT_UNALIGNED(struct rb_io_buffer_t { +struct stat; +struct timeval; + +/** + * Indicates that a timeout has occurred while performing an IO operation. + */ +RUBY_EXTERN VALUE rb_eIOTimeoutError; + +/** + * Type of events that an IO can wait. + * + * @internal + * + * This is visible from extension libraries because `io/wait` wants it. + */ +enum rb_io_event { + RUBY_IO_READABLE = RB_WAITFD_IN, /**< `IO::READABLE` */ + RUBY_IO_WRITABLE = RB_WAITFD_OUT, /**< `IO::WRITABLE` */ + RUBY_IO_PRIORITY = RB_WAITFD_PRI, /**< `IO::PRIORITY` */ +}; + +typedef enum rb_io_event rb_io_event_t; + +/** + * IO buffers. This is an implementation detail of ::rb_io_t::wbuf and + * ::rb_io_t::rbuf. People don't manipulate it directly. + */ +RBIMPL_ATTR_PACKED_STRUCT_UNALIGNED_BEGIN() +struct rb_io_internal_buffer { + + /** Pointer to the underlying memory region, of at least `capa` bytes. */ char *ptr; /* off + len <= capa */ + + /** Offset inside of `ptr`. */ int off; + + /** Length of the buffer. */ int len; + + /** Designed capacity of the buffer. */ int capa; -}); -typedef struct rb_io_buffer_t rb_io_buffer_t; +} RBIMPL_ATTR_PACKED_STRUCT_UNALIGNED_END(); -typedef struct rb_io_t { +/** @alias{rb_io_buffer_t} */ +typedef struct rb_io_internal_buffer rb_io_buffer_t; + +/** Decomposed encoding flags (e.g. `"enc:enc2""`). */ +/* + * enc enc2 read action write action + * NULL NULL force_encoding(default_external) write the byte sequence of str + * e1 NULL force_encoding(e1) convert str.encoding to e1 + * e1 e2 convert from e2 to e1 convert str.encoding to e2 + */ +struct rb_io_encoding { + /** Internal encoding. */ + rb_encoding *enc; + /** External encoding. */ + rb_encoding *enc2; + /** + * Flags. + * + * @see enum ::ruby_econv_flag_type + */ + int ecflags; + /** + * Flags as Ruby hash. + * + * @internal + * + * This is set. But used from nowhere maybe? + */ + VALUE ecopts; +}; + +#ifndef HAVE_RB_IO_T +#define HAVE_RB_IO_T 1 +/** Ruby's IO, metadata and buffers. */ +struct rb_io { + /** The IO's Ruby level counterpart. */ + RBIMPL_ATTR_DEPRECATED(("with no replacement")) VALUE self; - FILE *stdio_file; /* stdio ptr for read/write if available */ - int fd; /* file descriptor */ - int mode; /* mode flags: FMODE_XXXs */ - rb_pid_t pid; /* child's pid (for pipes) */ - int lineno; /* number of lines read */ - VALUE pathv; /* pathname for file */ - void (*finalize)(struct rb_io_t*,int); /* finalize proc */ + /** stdio ptr for read/write, if available. */ + RBIMPL_ATTR_DEPRECATED(("with no replacement")) + FILE *stdio_file; - rb_io_buffer_t wbuf, rbuf; + /** file descriptor. */ + RBIMPL_ATTR_DEPRECATED(("rb_io_descriptor")) + int fd; - VALUE tied_io_for_writing; + /** mode flags: FMODE_XXXs */ + RBIMPL_ATTR_DEPRECATED(("rb_io_mode")) + int mode; + + /** child's pid (for pipes) */ + RBIMPL_ATTR_DEPRECATED(("with no replacement")) + rb_pid_t pid; + + /** number of lines read */ + RBIMPL_ATTR_DEPRECATED(("with no replacement")) + int lineno; + + /** pathname for file */ + RBIMPL_ATTR_DEPRECATED(("rb_io_path")) + VALUE pathv; + + /** finalize proc */ + RBIMPL_ATTR_DEPRECATED(("with no replacement")) + void (*finalize)(struct rb_io*,int); + + /** Write buffer. */ + RBIMPL_ATTR_DEPRECATED(("with no replacement")) + rb_io_buffer_t wbuf; + + /** + * (Byte) read buffer. Note also that there is a field called + * ::rb_io_t::cbuf, which also concerns read IO. + */ + RBIMPL_ATTR_DEPRECATED(("with no replacement")) + rb_io_buffer_t rbuf; - /* - * enc enc2 read action write action - * NULL NULL force_encoding(default_external) write the byte sequence of str - * e1 NULL force_encoding(e1) convert str.encoding to e1 - * e1 e2 convert from e2 to e1 convert str.encoding to e2 + /** + * Duplex IO object, if set. + * + * @see rb_io_set_write_io() */ - struct rb_io_enc_t { - rb_encoding *enc; - rb_encoding *enc2; - int ecflags; - VALUE ecopts; - } encs; + RBIMPL_ATTR_DEPRECATED(("rb_io_get_write_io")) + VALUE tied_io_for_writing; + RBIMPL_ATTR_DEPRECATED(("with no replacement")) + struct rb_io_encoding encs; /**< Decomposed encoding flags. */ + + /** Encoding converter used when reading from this IO. */ + RBIMPL_ATTR_DEPRECATED(("with no replacement")) rb_econv_t *readconv; + + /** + * rb_io_ungetc() destination. This buffer is read before checking + * ::rb_io_t::rbuf + */ + RBIMPL_ATTR_DEPRECATED(("with no replacement")) rb_io_buffer_t cbuf; + /** Encoding converter used when writing to this IO. */ + RBIMPL_ATTR_DEPRECATED(("with no replacement")) rb_econv_t *writeconv; + + /** + * This is, when set, an instance of ::rb_cString which holds the "common" + * encoding. Write conversion can convert strings twice... In case + * conversion from encoding X to encoding Y does not exist, Ruby finds an + * encoding Z that bridges the two, so that X to Z to Y conversion happens. + */ + RBIMPL_ATTR_DEPRECATED(("with no replacement")) VALUE writeconv_asciicompat; + + /** Whether ::rb_io_t::writeconv is already set up. */ + RBIMPL_ATTR_DEPRECATED(("with no replacement")) int writeconv_initialized; + + /** + * Value of ::rb_io_t::rb_io_enc_t::ecflags stored right before + * initialising ::rb_io_t::writeconv. + */ + RBIMPL_ATTR_DEPRECATED(("with no replacement")) int writeconv_pre_ecflags; + + /** + * Value of ::rb_io_t::rb_io_enc_t::ecopts stored right before initialising + * ::rb_io_t::writeconv. + */ + RBIMPL_ATTR_DEPRECATED(("with no replacement")) VALUE writeconv_pre_ecopts; + /** + * This is a Ruby level mutex. It avoids multiple threads to write to an + * IO at once; helps for instance rb_io_puts() to ensure newlines right + * next to its arguments. + * + * This of course doesn't help inter-process IO interleaves, though. + */ + RBIMPL_ATTR_DEPRECATED(("with no replacement")) VALUE write_lock; -} rb_io_t; -typedef struct rb_io_enc_t rb_io_enc_t; + /** + * The timeout associated with this IO when performing blocking operations. + */ + RBIMPL_ATTR_DEPRECATED(("rb_io_timeout/rb_io_set_timeout")) + VALUE timeout; +}; +#endif -#define HAVE_RB_IO_T 1 +typedef struct rb_io rb_io_t; + +/** @alias{rb_io_enc_t} */ +typedef struct rb_io_encoding rb_io_enc_t; + +/** + * @name Possible flags for ::rb_io_t::mode + * + * @{ + */ +/** The IO is opened for reading. */ #define FMODE_READABLE 0x00000001 + +/** The IO is opened for writing. */ #define FMODE_WRITABLE 0x00000002 + +/** The IO is opened for both read/write. */ #define FMODE_READWRITE (FMODE_READABLE|FMODE_WRITABLE) + +/** + * The IO is in "binary mode". This is not what everything rb_io_binmode() + * concerns. This low-level flag is to stop CR <-> CRLF conversions that would + * happen in the underlying operating system. + * + * Setting this one and #FMODE_TEXTMODE at the same time is a contradiction. + * Setting this one and #ECONV_NEWLINE_DECORATOR_MASK at the same time is also + * a contradiction. + */ #define FMODE_BINMODE 0x00000004 + +/** + * The IO is in "sync mode". All output is immediately flushed to the + * underlying operating system then. Can be set via rb_io_synchronized(), but + * there is no way except calling `IO#sync=` to reset. + */ #define FMODE_SYNC 0x00000008 + +/** + * The IO is a TTY. What is a TTY and what isn't depends on the underlying + * operating system's `isatty(3)` output. You cannot change this. + */ #define FMODE_TTY 0x00000010 + +/** + * Ruby eventually detects that the IO is bidirectional. For instance a TTY + * has such property. There are several other things known to be duplexed. + * Additionally you (extension library authors) can also implement your own + * bidirectional IO subclasses. One of such example is `Socket`. + */ #define FMODE_DUPLEX 0x00000020 + +/** + * The IO is opened for appending. This mode always writes at the end of the + * IO. Ruby manages this flag for record but basically the logic behind this + * mode is at the underlying operating system. We almost do nothing. + */ #define FMODE_APPEND 0x00000040 + +/** + * The IO is opened for creating. This makes sense only when the destination + * file does not exist at the time the IO object was created. This is the + * default mode for writing, but you can pass `"r+"` to `IO.open` etc., to + * reroute this creation. + */ #define FMODE_CREATE 0x00000080 /* #define FMODE_NOREVLOOKUP 0x00000100 */ + +/** + * This flag amends the effect of #FMODE_CREATE, so that if there already is a + * file at the given path the operation fails. Using this you can be sure that + * the file you get is a fresh new one. + */ #define FMODE_EXCL 0x00000400 + +/** + * This flag amends the effect of #FMODE_CREATE, so that if there already is a + * file at the given path it gets truncated. + */ #define FMODE_TRUNC 0x00000800 + +/** + * The IO is in "text mode". On systems where such mode make sense, this flag + * changes the way the IO handles the contents. On POSIX systems it is + * basically a no-op, but with this flag set you can optionally let Ruby + * manually convert newlines, unlike when in binary mode: + * + * ```ruby + * IO.open("/p/a/t/h", "wt", crlf_newline: true) # "wb" is NG. + * ``` + * + * Setting this one and #FMODE_BINMODE at the same time is a contradiction. + */ #define FMODE_TEXTMODE 0x00001000 -/* #define FMODE_PREP 0x00010000 */ +/** + * This flag means that an IO object is wrapping an "external" file descriptor, + * which is owned by something outside the Ruby interpreter (usually a C extension). + * Ruby will not close this file when the IO object is garbage collected. + * If this flag is set, then IO#autoclose? is false, and vice-versa. + * + * This flag was previously called FMODE_PREP internally. + */ +#define FMODE_EXTERNAL 0x00010000 + +/* #define FMODE_SIGNAL_ON_EPIPE 0x00020000 */ + +/** + * This flag amends the encoding of the IO so that the BOM of the contents of + * the IO takes effect. + */ #define FMODE_SETENC_BY_BOM 0x00100000 /* #define FMODE_UNIX 0x00200000 */ /* #define FMODE_INET 0x00400000 */ /* #define FMODE_INET6 0x00800000 */ +/** @} */ + +/** + * Allocate a new IO object, with the given file descriptor. + */ +VALUE rb_io_open_descriptor(VALUE klass, int descriptor, int mode, VALUE path, VALUE timeout, struct rb_io_encoding *encoding); + +/** + * Returns whether or not the underlying IO is closed. + * + * @return Whether the underlying IO is closed. + */ +VALUE rb_io_closed_p(VALUE io); + +/** + * Queries the underlying IO pointer. + * + * @param[in] obj An IO object. + * @param[out] fp A variable of type ::rb_io_t. + * @exception rb_eFrozenError `obj` is frozen. + * @exception rb_eIOError `obj` is closed. + * @post `fp` holds `obj`'s underlying IO. + */ #define RB_IO_POINTER(obj,fp) rb_io_check_closed((fp) = RFILE(rb_io_taint_check(obj))->fptr) + +/** + * This is an old name of #RB_IO_POINTER. Not sure if we want to deprecate + * this macro. There still are tons of usages out there in the wild. + */ #define GetOpenFile RB_IO_POINTER +/** + * Fills an IO object. This makes the best sense when called from inside of an + * `#initialize` method of a 3rd party extension library that inherits + * ::rb_cIO. + * + * If the passed IO is already opened for something it first closes that and + * opens a new one instead. + * + * @param[out] obj An IO object to fill in. + * @param[out] fp A variable of type ::rb_io_t. + * @exception rb_eTypeError `obj` is not ::RUBY_T_FILE. + * @post `fp` holds `obj`'s underlying IO. + */ #define RB_IO_OPEN(obj, fp) do {\ (fp) = rb_io_make_open_file(obj);\ } while (0) + +/** + * This is an old name of #RB_IO_OPEN. Not sure if we want to deprecate this + * macro. There still are usages out there in the wild. + */ #define MakeOpenFile RB_IO_OPEN +/** + * @private + * + * This is an implementation detail of #RB_IO_OPEN. People don't use it + * directly. + * + * @param[out] obj An IO object to fill in. + * @exception rb_eTypeError `obj` is not ::RUBY_T_FILE. + * @return `obj`'s backend IO. + * @post `obj` is initialised. + */ rb_io_t *rb_io_make_open_file(VALUE obj); +/** + * Finds or creates a stdio's file structure from a Ruby's one. This can be + * handy if you want to call an external API that accepts `FILE *`. + * + * @note Note however, that `FILE`s can have their own buffer. Mixing Ruby's + * and stdio's file are basically dangerous. Use with care. + * + * @param[in,out] fptr Target IO. + * @return A stdio's file, created if absent. + * @post `fptr` has its corresponding stdio's file. + * + * @internal + * + * We had rich support for `FILE` before! In the days of 1.8.x ::rb_io_t was + * like this: + * + * ```CXX + * typedef struct rb_io { + * FILE *f; // stdio ptr for read/write + * FILE *f2; // additional ptr for rw pipes + * int mode; // mode flags + * int pid; // child's pid (for pipes) + * int lineno; // number of lines read + * char *path; // pathname for file + * void (*finalize) _((struct rb_io*,int)); // finalize proc + * } rb_io_t; + *``` + * + * But we eventually abandoned this layout. It was too difficult. We could + * not have fine-grained control over the `f` field. + * + * - `FILE` tends to be an opaque struct. It does not interface well with + * `select(2)` etc. This makes IO multiplexing quite hard. Using stdio, + * there is arguably no portable way to know if `fwrite(3)` blocks. + * + * - Nonblocking mode, which is another core concept that enables IO + * multiplexing, does not interface with stdio routines at all. + * + * - Detection of duplexed IO is also hard for the same reason. + * + * - `feof(3)` is not portable. + * https://mail.python.org/pipermail/python-dev/2001-January/011390.html + * + * - Solaris was a thing back then. They could not have more than 256 `FILE` + * structures at a time. Their file descriptors ware stored in an + * `unsigned char`. + * + * - It is next to impossible to avoid SEGV, especially when a thread tries to + * `ungetc(3)`-ing from a `FILE` which is `fread(3)`-ed by another one. + * + * In short, it is a bad idea to let someone else manage IO buffers, especially + * someone you cannot control. This still applies to extension libraries + * methinks. Ruby doesn't prevent you from shooting yourself in the foot, but + * consider yourself warned here. + */ FILE *rb_io_stdio_file(rb_io_t *fptr); -FILE *rb_fdopen(int, const char*); +/** + * Identical to rb_io_stdio_file(), except it takes file descriptors instead of + * Ruby's IO. It can also be seen as a compatibility layer to wrap + * `fdopen(3)`. Nowadays all supporting systems, including Windows, have + * `fdopen`. Why not use them. + * + * @param[in] fd A file descriptor. + * @param[in] modestr C string, something like `"r+"`. + * @exception rb_eSystemCallError `fdopen` failed for some reason. + * @return A stdio's file associated with `fd`. + * @note Interpretation of `modestr` depends on the underlying operating + * system. On glibc you might be able to pass e.g. `"rm"`, but + * that's an extension to POSIX. + */ +FILE *rb_fdopen(int fd, const char *modestr); + +/** + * Maps a file mode string (that rb_file_open() takes) into a mixture of + * `FMODE_` flags. This for instance returns + * `FMODE_WRITABLE | FMODE_TRUNC | FMODE_CREATE | FMODE_EXCL` for `"wx"`. + * + * @note You cannot pass this return value to OS provided `open(2)` etc. + * + * @param[in] modestr File mode, in C's string. + * @exception rb_eArgError `modestr` is broken. + * @return A set of flags. + * + * @internal + * + * rb_io_modestr_fmode() is not a pure function because it raises. + */ int rb_io_modestr_fmode(const char *modestr); + +/** + * Identical to rb_io_modestr_fmode(), except it returns a mixture of `O_` + * flags. This for instance returns `O_WRONLY | O_TRUNC | O_CREAT | O_EXCL` for + * `"wx"`. + * + * @param[in] modestr File mode, in C's string. + * @exception rb_eArgError `modestr` is broken. + * @return A set of flags. + * + * @internal + * + * rb_io_modestr_oflags() is not a pure function because it raises. + */ int rb_io_modestr_oflags(const char *modestr); -CONSTFUNC(int rb_io_oflags_fmode(int oflags)); -void rb_io_check_writable(rb_io_t*); -void rb_io_check_readable(rb_io_t*); + +RBIMPL_ATTR_CONST() +/** + * Converts an oflags (that rb_io_modestr_oflags() returns) to a fmode (that + * rb_io_mode_flags() returns). This is a purely functional operation. + * + * @param[in] oflags A set of `O_` flags. + * @return Corresponding set of `FMODE_` flags. + */ +int rb_io_oflags_fmode(int oflags); + +/** + * Asserts that an IO is opened for writing. + * + * @param[in] fptr An IO you want to write to. + * @exception rb_eIOError `fptr` is not for writing. + * @post Upon successful return `fptr` is ready for writing. + * + * @internal + * + * The parameter must have been `const rb_io_t *`. + */ +void rb_io_check_writable(rb_io_t *fptr); + +/** @alias{rb_io_check_byte_readable} */ +void rb_io_check_readable(rb_io_t *fptr); + +/** + * Asserts that an IO is opened for character-based reading. A character can + * be wider than a byte. Because of this we have to buffer reads from + * descriptors. This fiction checks if that is possible. + * + * @param[in] fptr An IO you want to read characters from. + * @exception rb_eIOError `fptr` is not for reading. + * @post Upon successful return `fptr` is ready for reading characters. + * + * @internal + * + * Unlike rb_io_check_writable() the parameter cannot be `const rb_io_t *`. + * Behind the scene this operation flushes its write buffers. This is because + * of OpenSSL. They mandate this way. + * + * @see "Can I use OpenSSL's SSL library with non-blocking I/O?" + * https://www.openssl.org/docs/faq.html + */ void rb_io_check_char_readable(rb_io_t *fptr); + +/** + * Asserts that an IO is opened for byte-based reading. Byte-based and + * character-based reading operations cannot be mixed at a time. + * + * @param[in] fptr An IO you want to read characters from. + * @exception rb_eIOError `fptr` is not for reading. + * @post Upon successful return `fptr` is ready for reading bytes. + */ void rb_io_check_byte_readable(rb_io_t *fptr); -int rb_io_fptr_finalize(rb_io_t*); -void rb_io_synchronized(rb_io_t*); -void rb_io_check_initialized(rb_io_t*); -void rb_io_check_closed(rb_io_t*); + +/** + * Destroys the given IO. Any pending operations are flushed. + * + * @note It makes no sense to call this function from anywhere outside of your + * class' ::rb_data_type_struct::dfree. + * + * @param[out] fptr IO to close. + * @post `fptr` is no longer a valid pointer. + */ +int rb_io_fptr_finalize(rb_io_t *fptr); + +/** + * Sets #FMODE_SYNC. + * + * @note There is no way for C extensions to undo this operation. + * + * @param[out] fptr IO to set the flag. + * @exception rb_eIOError `fptr` is not opened. + * @post `fptr` is in sync mode. + */ +void rb_io_synchronized(rb_io_t *fptr); + +/** + * Asserts that the passed IO is initialised. + * + * @param[in] fptr IO that you expect be initialised. + * @exception rb_eIOError `fptr` is not initialised. + * @post `fptr` is initialised. + */ +void rb_io_check_initialized(rb_io_t *fptr); + +/** + * This badly named function asserts that the passed IO is _open_. + * + * @param[in] fptr An IO + * @exception rb_eIOError `fptr` is closed. + * @post `fptr` is open. + */ +void rb_io_check_closed(rb_io_t *fptr); + +/** + * Identical to rb_io_check_io(), except it raises exceptions on conversion + * failures. + * + * @param[in] io Target object. + * @exception rb_eTypeError No implicit conversion to IO. + * @return Return value of `obj.to_io`. + * @see rb_str_to_str + * @see rb_ary_to_ary + */ VALUE rb_io_get_io(VALUE io); + +/** + * Try converting an object to its IO representation using its `to_io` method, + * if any. If there is no such thing, returns ::RUBY_Qnil. + * + * @param[in] io Arbitrary ruby object to convert. + * @exception rb_eTypeError `obj.to_io` returned something non-IO. + * @retval RUBY_Qnil No conversion from `obj` to IO defined. + * @retval otherwise Converted IO representation of `obj`. + * @see rb_check_array_type + * @see rb_check_string_type + * @see rb_check_hash_type + */ VALUE rb_io_check_io(VALUE io); + +/** + * Queries the tied IO for writing. An IO can be duplexed. Fine. The thing + * is, that characteristics could sometimes be achieved by the underlying + * operating system (for instance a socket's duplexity is by nature) but + * sometimes by us. Notable example is a bidirectional pipe. Suppose you + * have: + * + * ```ruby + * fp = IO.popen("-", "r+") + * ``` + * + * This pipe is duplexed (the `"r+"`). You can both read from/write to it. + * However your operating system may or may not implement bidirectional pipes. + * FreeBSD is one of such operating systems known to have one; OTOH Linux is + * known to lack such things. So to achieve maximum portability, Ruby's + * bidirectional pipes are done purely in user land. A pipe in ruby can have + * multiple file descriptors; one for reading and the other for writing. This + * API is to obtain the IO port which corresponds to the passed one, for + * writing. + * + * @param[in] io An IO. + * @return Its tied IO for writing, if any, or `io` itself otherwise. + */ VALUE rb_io_get_write_io(VALUE io); + +/** + * Assigns the tied IO for writing. See rb_io_get_write_io() for what a "tied + * IO for writing" is. + * + * @param[out] io An IO. + * @param[in] w Another IO. + * @retval RUBY_Qnil There was no tied IO for writing for `io`. + * @retval otherwise The IO formerly tied to `io`. + * @post `io` ties `w` for writing. + * + * @internal + * + * @shyouhei doesn't think there is any needs of this function for 3rd party + * extension libraries. + */ VALUE rb_io_set_write_io(VALUE io, VALUE w); + +/** + * Instructs the OS to put its internal file structure into "nonblocking mode". + * This is an in-Kernel concept. Reading from/writing to that file using C + * function calls would return -1 with errno set. However when it comes to a + * ruby program, we hide that error behind our `IO#read` method. Ruby level + * `IO#read` blocks regardless of this flag. If you want to avoid blocking, + * you should consider using methods like `IO#readpartial`. + * + * ```ruby + * require 'io/nonblock' + * STDIN.nonblock = true + * STDIN.gets # blocks. + * ``` + * + * As of writing there is a room of this API in Fiber schedulers. A Fiber + * scheduler could be written in a way its behaviour depends on this property. + * You need an in-depth understanding of how schedulers work to properly + * leverage this, though. + * + * @note Note however that nonblocking-ness propagates across process + * boundaries. You must really carefully watch your step when turning + * for instance `stderr` into nonblock mode (it tends to be shared + * across many processes). Also it is a complete disaster to mix a + * nonblocking file and stdio, and `stderr` tends to be under control of + * stdio in other processes. + * + * @param[out] fptr An IO that is to ne nonblocking. + * @post Descriptor that `fptr` describes is under nonblocking mode. + * + * @internal + * + * There is `O_NONBLOCK` but not `FMODE_NONBLOCK`. You cannot atomically + * create a nonblocking file descriptor using our API. + */ void rb_io_set_nonblock(rb_io_t *fptr); + +/** + * Returns the path for the given IO. + * + */ +VALUE rb_io_path(VALUE io); + +/** + * Returns an integer representing the numeric file descriptor for + * <em>io</em>. + * + * @param[in] io An IO. + * @retval int A file descriptor. + */ +int rb_io_descriptor(VALUE io); + +/** + * Get the mode of the IO. + * + */ +int rb_io_mode(VALUE io); + +/** + * This function breaks down the option hash that `IO#initialize` takes into + * components. This is an implementation detail of rb_io_extract_modeenc() + * today. People prefer that API instead. + * + * @param[in] opt The hash to decompose. + * @param[out] enc_p Return value buffer. + * @param[out] enc2_p Return value buffer. + * @param[out] fmode_p Return value buffer. + * @exception rb_eTypeError `opt` is broken. + * @exception rb_eArgError Specified encoding does not exist. + * @retval 1 Components got extracted. + * @retval 0 Otherwise. + * @post `enc_p` is the specified internal encoding. + * @post `enc2_p` is the specified external encoding. + * @post `fmode_p` is the specified set of `FMODE_` modes. + */ int rb_io_extract_encoding_option(VALUE opt, rb_encoding **enc_p, rb_encoding **enc2_p, int *fmode_p); + +/** + * This function can be seen as an extended version of + * rb_io_extract_encoding_option() that not only concerns the option hash but + * also mode string and so on. This should be mixed with rb_scan_args() like: + * + * ```CXX + * // This method mimics File.new + * static VALUE + * your_method(int argc, const VALUE *argv, VALUE self) + * { + * VALUE f; // file name + * VALUE m; // open mode + * VALUE p; // permission (O_CREAT) + * VALUE k; // keywords + * rb_io_enc_t c; // converter + * int oflags; + * int fmode; + * + * int n = rb_scan_args(argc, argv, "12:", &f, &m, &p, &k); + * rb_io_extract_modeenc(&m, &p, k, &oflags, &fmode, &c); + * + * // Every local variables declared so far has been properly filled here. + * ... + * } + * ``` + * + * @param[in,out] vmode_p Pointer to a mode object. + * @param[in,out] vperm_p Pointer to a permission object. + * @param[in] opthash Keyword arguments + * @param[out] oflags_p `O_` flags return buffer. + * @param[out] fmode_p `FMODE_` flags return buffer. + * @param[out] convconfig_p Encoding config return buffer. + * @exception rb_eTypeError Unexpected object (e.g. Time) passed. + * @exception rb_eArgError Contradiction inside of params. + * @post `*vmode_p` is a mode object (filled if any). + * @post `*vperm_p` is a permission object (filled if any). + * @post `*oflags_p` is filled with `O_` flags. + * @post `*fmode_p` is filled with `FMODE_` flags. + * @post `*convconfig_p` is filled with conversion instructions. + * + * @internal + * + * ```rbs + * class File + * def initialize: ( + * (String | int) path, + * ?(String | int) fmode, + * ?(String | int) perm, + * ?mode: (String | int), + * ?flags: int, + * ?external_encoding: (Encoding | String), + * ?internal_encoding: (Encoding | String), + * ?encoding: String, + * ?textmode: bool, + * ?binmode: bool, + * ?autoclose: bool, + * ?invalid: :replace, + * ?undef: :replace, + * ?replace: String, + * ?fallback: (Hash | Proc | Method), + * ?xml: (:text | :attr), + * ?crlf_newline: bool, + * ?cr_newline: bool, + * ?universal_newline: bool + * ) -> void + * ``` + */ void rb_io_extract_modeenc(VALUE *vmode_p, VALUE *vperm_p, VALUE opthash, int *oflags_p, int *fmode_p, rb_io_enc_t *convconfig_p); + +/* :TODO: can this function be __attribute__((warn_unused_result)) or not? */ +/** + * Buffered write to the passed IO. + * + * @param[out] io Destination IO. + * @param[in] buf Contents to go to `io`. + * @param[in] size Number of bytes of `buf`. + * @exception rb_eFrozenError `io` is frozen. + * @exception rb_eIOError `io` is not open for writing. + * @exception rb_eSystemCallError `writev(2)` failed for some reason. + * @retval -1 Write failed. + * @retval otherwise Number of bytes actually written. + * @post `buf` is written to `io`. + * @note Partial write is a thing. It is a failure not to check the + * return value. + */ ssize_t rb_io_bufwrite(VALUE io, const void *buf, size_t size); +//RBIMPL_ATTR_DEPRECATED(("use rb_io_maybe_wait_readable")) +/** + * Blocks until the passed file descriptor gets readable. + * + * @deprecated We now prefer rb_io_maybe_wait_readable() over this one. + * @param[in] fd The file descriptor to wait. + * @exception rb_eIOError Bad file descriptor. + * @return 0 or 1 (meaning unclear). + * @post `fd` is ready for reading. + */ int rb_io_wait_readable(int fd); + +//RBIMPL_ATTR_DEPRECATED(("use rb_io_maybe_wait_writable")) +/** + * Blocks until the passed file descriptor gets writable. + * + * @deprecated We now prefer rb_io_maybe_wait_writable() over this one. + * @param[in] fd The file descriptor to wait. + * @exception rb_eIOError Bad file descriptor. + * @return 0 or 1 (meaning unclear). + */ int rb_io_wait_writable(int fd); + +//RBIMPL_ATTR_DEPRECATED(("use rb_io_wait")) +/** + * Blocks until the passed file descriptor is ready for the passed events. + * + * @deprecated We now prefer rb_io_maybe_wait() over this one. + * @param[in] fd The file descriptor to wait. + * @param[in] events A set of enum ::rb_io_event_t. + * @param[in,out] tv Timeout. + * @retval 0 Operation timed out. + * @retval -1 `select(2)` failed for some reason. + * @retval otherwise A set of enum ::rb_io_event_t. + * @note Depending on your operating system `tv` might or might not + * be updated (POSIX permits both). Portable programs must + * have no assumptions. + */ int rb_wait_for_single_fd(int fd, int events, struct timeval *tv); +/** + * Get the timeout associated with the specified io object. + * + * @param[in] io An IO object. + * @retval RUBY_Qnil There is no associated timeout. + * @retval Otherwise The timeout value. + */ +VALUE rb_io_timeout(VALUE io); + +/** + * Set the timeout associated with the specified io object. This timeout is + * used as a best effort timeout to prevent operations from blocking forever. + * + * @param[in] io An IO object. + * @param[in] timeout A timeout value. Must respond to #to_f. + * @ + */ +VALUE rb_io_set_timeout(VALUE io, VALUE timeout); + +/** + * Blocks until the passed IO is ready for the passed events. The "events" + * here is a Ruby level integer, which is an OR-ed value of `IO::READABLE`, + * `IO::WRITable`, and `IO::PRIORITY`. + * + * If timeout is `Qnil`, it will use the default timeout as given by + * `rb_io_timeout(io)`. + * + * @param[in] io An IO object to wait. + * @param[in] events See above. + * @param[in] timeout Time, or numeric seconds since UNIX epoch. + * If Qnil, use the default timeout. If Qfalse + * or Qundef, wait forever. + * @exception rb_eIOError `io` is not open. + * @exception rb_eRangeError `timeout` is out of range. + * @exception rb_eSystemCallError `select(2)` failed for some reason. + * @retval RUBY_Qfalse Operation timed out. + * @retval Otherwise Actual events reached. + */ VALUE rb_io_wait(VALUE io, VALUE events, VALUE timeout); +/** + * Identical to rb_io_wait() except it additionally takes previous errno. If + * the passed errno indicates for instance `EINTR`, this function returns + * immediately. This is expected to be called in a loop. + * + * ```CXX + * while (true) { + * + * ... // Your interesting operation here + * // `errno` could be updated + * + * rb_io_maybe_wait(errno, io, ev, Qnil); + * } + * ``` + * + * @param[in] error System errno. + * @param[in] io An IO object to wait. + * @param[in] events An integer set of interests. + * @param[in] timeout Time, or numeric seconds since UNIX epoch. + * @exception rb_eIOError `io` is not open. + * @exception rb_eRangeError `timeout` is out of range. + * @exception rb_eSystemCallError `select(2)` failed for some reason. + * @retval RUBY_Qfalse Operation timed out. + * @retval Otherwise Actual events reached. + * + * @internal + * + * This function to return ::RUBY_Qfalse on timeout could be unintended. It + * seems timeout feature has some rough edge. + */ +VALUE rb_io_maybe_wait(int error, VALUE io, VALUE events, VALUE timeout); + +/** + * Blocks until the passed IO is ready for reading, if that makes sense for the + * passed errno. This is a special case of rb_io_maybe_wait() that only + * concerns for reading. + * + * @param[in] error System errno. + * @param[in] io An IO object to wait. + * @param[in] timeout Time, or numeric seconds since UNIX epoch. + * @exception rb_eIOError `io` is not open. + * @exception rb_eRangeError `timeout` is out of range. + * @exception rb_eSystemCallError `select(2)` failed for some reason. + * @retval 0 Operation timed out. + * @retval Otherwise Always returns ::RUBY_IO_READABLE. + */ +int rb_io_maybe_wait_readable(int error, VALUE io, VALUE timeout); + +/** + * Blocks until the passed IO is ready for writing, if that makes sense for the + * passed errno. This is a special case of rb_io_maybe_wait() that only + * concernsfor writing. + * + * @param[in] error System errno. + * @param[in] io An IO object to wait. + * @param[in] timeout Time, or numeric seconds since UNIX epoch. + * @exception rb_eIOError `io` is not open. + * @exception rb_eRangeError `timeout` is out of range. + * @exception rb_eSystemCallError `select(2)` failed for some reason. + * @retval 0 Operation timed out. + * @retval Otherwise Always returns ::RUBY_IO_WRITABLE. + */ +int rb_io_maybe_wait_writable(int error, VALUE io, VALUE timeout); + +/** @cond INTERNAL_MACRO */ /* compatibility for ruby 1.8 and older */ #define rb_io_mode_flags(modestr) [<"rb_io_mode_flags() is obsolete; use rb_io_modestr_fmode()">] #define rb_io_modenum_flags(oflags) [<"rb_io_modenum_flags() is obsolete; use rb_io_oflags_fmode()">] +/** @endcond */ -VALUE rb_io_taint_check(VALUE); -NORETURN(void rb_eof_error(void)); +/** + * @deprecated This function once was a thing in the old days, but makes no + * sense any longer today. Exists here for backwards + * compatibility only. You can safely forget about it. + * + * @param[in] obj Object in question. + * @exception rb_eFrozenError obj is frozen. + * @return The passed `obj` + */ +VALUE rb_io_taint_check(VALUE obj); -void rb_io_read_check(rb_io_t*); -int rb_io_read_pending(rb_io_t*); +RBIMPL_ATTR_NORETURN() +/** + * Utility function to raise ::rb_eEOFError. + * + * @exception rb_eEOFError End of file situation. + * @note It never returns. + */ +void rb_eof_error(void); -struct stat; -VALUE rb_stat_new(const struct stat *); +/** + * Blocks until there is a pending read in the passed IO. If there already is + * it just returns. + * + * @param[out] fptr An IO to wait for reading. + * @post The are bytes to be read. + */ +void rb_io_read_check(rb_io_t *fptr); + +RBIMPL_ATTR_PURE() +/** + * Queries if the passed IO has any pending reads. Unlike rb_io_read_check() + * this doesn't block; has no side effects. + * + * @param[in] fptr An IO which can have pending reads. + * @retval 0 The IO is empty. + * @retval 1 There is something buffered. + */ +int rb_io_read_pending(rb_io_t *fptr); + +/** + * Constructs an instance of ::rb_cStat from the passed information. + * + * @param[in] st A stat. + * @return Allocated new instance of ::rb_cStat. + */ +VALUE rb_stat_new(const struct stat *st); /* gc.c */ |