Crate wasi

Raw API bindings to the WebAssembly System Interface (WASI)

This crate provides Rust API bindings to WASI APIs. All WASI APIs are exported from this crate and provided with the appropriate type signatures. This crate is entirely procedurally generated from the *.witx files that describe the WASI API.

WASI API Version

The WASI API is evolving over time. It is both gaining new features as well as tweaking the ABI of existing features. As a result it's important to understand what version of this crate you're using and how it relates to the WASI version of the spec.

The WASI specification is organized into phases where there is a snapshot at any one point in time describing the current state of the specification. This crate implements a particular snapshot. You can find the snapshot version implemented in this crate in the build metadata of the crate version number. For example something like 0.9.0+wasi-snapshot-preview1 means that this crate's own personal version is 0.9.0 and it implements the wasi-snapshot-preview1 snapshot. A major release of this crate (i.e. bumping the "0.9.0") is expected whenever the generated code changes or a new WASI snapshot is used.

Crate Features

This crate supports one feature, std, which implements the standard Error trait for the exported Error type in this crate. This is enabled by default but can be disabled to make the library no_std compatible.

Modules

wasi_snapshot_preview1

Structs

Ciovec
Dirent
Error	A raw error returned by wasi APIs, internally containing a 16-bit error code.
Event
EventFdReadwrite
Fdstat
Filestat
Iovec
Prestat
PrestatDir
Subscription
SubscriptionClock
SubscriptionFdReadwrite

Constants

ADVICE_DONTNEED	The application expects that it will not access the specified data in the near future.
ADVICE_NOREUSE	The application expects to access the specified data once and then not reuse it thereafter.
ADVICE_NORMAL	The application has no advice to give on its behavior with respect to the specified data.
ADVICE_RANDOM	The application expects to access the specified data in a random order.
ADVICE_SEQUENTIAL	The application expects to access the specified data sequentially from lower offsets to higher offsets.
ADVICE_WILLNEED	The application expects to access the specified data in the near future.
CLOCKID_MONOTONIC	The store-wide monotonic clock, which is defined as a clock measuring real time, whose value cannot be adjusted and which cannot have negative clock jumps. The epoch of this clock is undefined. The absolute time value of this clock therefore has no meaning.
CLOCKID_PROCESS_CPUTIME_ID	The CPU-time clock associated with the current process.
CLOCKID_REALTIME	The clock measuring real time. Time value zero corresponds with 1970-01-01T00:00:00Z.
CLOCKID_THREAD_CPUTIME_ID	The CPU-time clock associated with the current thread.
ERRNO_2BIG	Argument list too long.
ERRNO_ACCES	Permission denied.
ERRNO_ADDRINUSE	Address in use.
ERRNO_ADDRNOTAVAIL	Address not available.
ERRNO_AFNOSUPPORT	Address family not supported.
ERRNO_AGAIN	Resource unavailable, or operation would block.
ERRNO_ALREADY	Connection already in progress.
ERRNO_BADF	Bad file descriptor.
ERRNO_BADMSG	Bad message.
ERRNO_BUSY	Device or resource busy.
ERRNO_CANCELED	Operation canceled.
ERRNO_CHILD	No child processes.
ERRNO_CONNABORTED	Connection aborted.
ERRNO_CONNREFUSED	Connection refused.
ERRNO_CONNRESET	Connection reset.
ERRNO_DEADLK	Resource deadlock would occur.
ERRNO_DESTADDRREQ	Destination address required.
ERRNO_DOM	Mathematics argument out of domain of function.
ERRNO_DQUOT	Reserved.
ERRNO_EXIST	File exists.
ERRNO_FAULT	Bad address.
ERRNO_FBIG	File too large.
ERRNO_HOSTUNREACH	Host is unreachable.
ERRNO_IDRM	Identifier removed.
ERRNO_ILSEQ	Illegal byte sequence.
ERRNO_INPROGRESS	Operation in progress.
ERRNO_INTR	Interrupted function.
ERRNO_INVAL	Invalid argument.
ERRNO_IO	I/O error.
ERRNO_ISCONN	Socket is connected.
ERRNO_ISDIR	Is a directory.
ERRNO_LOOP	Too many levels of symbolic links.
ERRNO_MFILE	File descriptor value too large.
ERRNO_MLINK	Too many links.
ERRNO_MSGSIZE	Message too large.
ERRNO_MULTIHOP	Reserved.
ERRNO_NAMETOOLONG	Filename too long.
ERRNO_NETDOWN	Network is down.
ERRNO_NETRESET	Connection aborted by network.
ERRNO_NETUNREACH	Network unreachable.
ERRNO_NFILE	Too many files open in system.
ERRNO_NOBUFS	No buffer space available.
ERRNO_NODEV	No such device.
ERRNO_NOENT	No such file or directory.
ERRNO_NOEXEC	Executable file format error.
ERRNO_NOLCK	No locks available.
ERRNO_NOLINK	Reserved.
ERRNO_NOMEM	Not enough space.
ERRNO_NOMSG	No message of the desired type.
ERRNO_NOPROTOOPT	Protocol not available.
ERRNO_NOSPC	No space left on device.
ERRNO_NOSYS	Function not supported.
ERRNO_NOTCAPABLE	Extension: Capabilities insufficient.
ERRNO_NOTCONN	The socket is not connected.
ERRNO_NOTDIR	Not a directory or a symbolic link to a directory.
ERRNO_NOTEMPTY	Directory not empty.
ERRNO_NOTRECOVERABLE	State not recoverable.
ERRNO_NOTSOCK	Not a socket.
ERRNO_NOTSUP	Not supported, or operation not supported on socket.
ERRNO_NOTTY	Inappropriate I/O control operation.
ERRNO_NXIO	No such device or address.
ERRNO_OVERFLOW	Value too large to be stored in data type.
ERRNO_OWNERDEAD	Previous owner died.
ERRNO_PERM	Operation not permitted.
ERRNO_PIPE	Broken pipe.
ERRNO_PROTO	Protocol error.
ERRNO_PROTONOSUPPORT	Protocol not supported.
ERRNO_PROTOTYPE	Protocol wrong type for socket.
ERRNO_RANGE	Result too large.
ERRNO_ROFS	Read-only file system.
ERRNO_SPIPE	Invalid seek.
ERRNO_SRCH	No such process.
ERRNO_STALE	Reserved.
ERRNO_SUCCESS	No error occurred. System call completed successfully.
ERRNO_TIMEDOUT	Connection timed out.
ERRNO_TXTBSY	Text file busy.
ERRNO_XDEV	Cross-device link.
EVENTRWFLAGS_FD_READWRITE_HANGUP	The peer of this socket has closed or disconnected.
EVENTTYPE_CLOCK	The time value of clock subscription::u.clock.clock_id has reached timestamp subscription::u.clock.timeout.
EVENTTYPE_FD_READ	File descriptor subscription::u.fd_readwrite.fd has data available for reading. This event always triggers for regular files.
EVENTTYPE_FD_WRITE	File descriptor subscription::u.fd_readwrite.fd has capacity available for writing. This event always triggers for regular files.
FDFLAGS_APPEND	Append mode: Data written to the file is always appended to the file's end.
FDFLAGS_DSYNC	Write according to synchronized I/O data integrity completion. Only the data stored in the file is synchronized.
FDFLAGS_NONBLOCK	Non-blocking mode.
FDFLAGS_RSYNC	Synchronized read I/O operations.
FDFLAGS_SYNC	Write according to synchronized I/O file integrity completion. In addition to synchronizing the data stored in the file, the implementation may also synchronously update the file's metadata.
FILETYPE_BLOCK_DEVICE	The file descriptor or file refers to a block device inode.
FILETYPE_CHARACTER_DEVICE	The file descriptor or file refers to a character device inode.
FILETYPE_DIRECTORY	The file descriptor or file refers to a directory inode.
FILETYPE_REGULAR_FILE	The file descriptor or file refers to a regular file inode.
FILETYPE_SOCKET_DGRAM	The file descriptor or file refers to a datagram socket.
FILETYPE_SOCKET_STREAM	The file descriptor or file refers to a byte-stream socket.
FILETYPE_SYMBOLIC_LINK	The file refers to a symbolic link inode.
FILETYPE_UNKNOWN	The type of the file descriptor or file is unknown or is different from any of the other types specified.
FSTFLAGS_ATIM	Adjust the last data access timestamp to the value stored in filestat::st_atim.
FSTFLAGS_ATIM_NOW	Adjust the last data access timestamp to the time of clock clock::realtime.
FSTFLAGS_MTIM	Adjust the last data modification timestamp to the value stored in filestat::st_mtim.
FSTFLAGS_MTIM_NOW	Adjust the last data modification timestamp to the time of clock clock::realtime.
LOOKUPFLAGS_SYMLINK_FOLLOW	As long as the resolved path corresponds to a symbolic link, it is expanded.
OFLAGS_CREAT	Create file if it does not exist.
OFLAGS_DIRECTORY	Fail if not a directory.
OFLAGS_EXCL	Fail if file already exists.
OFLAGS_TRUNC	Truncate file to size 0.
PREOPENTYPE_DIR	A pre-opened directory.
RIFLAGS_RECV_PEEK	Returns the message without removing it from the socket's receive queue.
RIFLAGS_RECV_WAITALL	On byte-stream sockets, block until the full amount of data can be returned.
RIGHTS_FD_ADVISE	The right to invoke fd_advise.
RIGHTS_FD_ALLOCATE	The right to invoke fd_allocate.
RIGHTS_FD_DATASYNC	The right to invoke fd_datasync. If path_open is set, includes the right to invoke path_open with fdflag::dsync.
RIGHTS_FD_FDSTAT_SET_FLAGS	The right to invoke fd_fdstat_set_flags.
RIGHTS_FD_FILESTAT_GET	The right to invoke fd_filestat_get.
RIGHTS_FD_FILESTAT_SET_SIZE	The right to invoke fd_filestat_set_size.
RIGHTS_FD_FILESTAT_SET_TIMES	The right to invoke fd_filestat_set_times.
RIGHTS_FD_READ	The right to invoke fd_read and sock_recv. If rights::fd_seek is set, includes the right to invoke fd_pread.
RIGHTS_FD_READDIR	The right to invoke fd_readdir.
RIGHTS_FD_SEEK	The right to invoke fd_seek. This flag implies rights::fd_tell.
RIGHTS_FD_SYNC	The right to invoke fd_sync. If path_open is set, includes the right to invoke path_open with fdflag::rsync and fdflag::dsync.
RIGHTS_FD_TELL	The right to invoke fd_seek in such a way that the file offset remains unaltered (i.e., WHENCE_CUR with offset zero), or to invoke fd_tell.
RIGHTS_FD_WRITE	The right to invoke fd_write and sock_send. If rights::fd_seek is set, includes the right to invoke fd_pwrite.
RIGHTS_PATH_CREATE_DIRECTORY	The right to invoke path_create_directory.
RIGHTS_PATH_CREATE_FILE	If path_open is set, the right to invoke path_open with oflags::creat.
RIGHTS_PATH_FILESTAT_GET	The right to invoke path_filestat_get.
RIGHTS_PATH_FILESTAT_SET_SIZE	The right to change a file's size (there is no path_filestat_set_size). If path_open is set, includes the right to invoke path_open with oflags::trunc.
RIGHTS_PATH_FILESTAT_SET_TIMES	The right to invoke path_filestat_set_times.
RIGHTS_PATH_LINK_SOURCE	The right to invoke path_link with the file descriptor as the source directory.
RIGHTS_PATH_LINK_TARGET	The right to invoke path_link with the file descriptor as the target directory.
RIGHTS_PATH_OPEN	The right to invoke path_open.
RIGHTS_PATH_READLINK	The right to invoke path_readlink.
RIGHTS_PATH_REMOVE_DIRECTORY	The right to invoke path_remove_directory.
RIGHTS_PATH_RENAME_SOURCE	The right to invoke path_rename with the file descriptor as the source directory.
RIGHTS_PATH_RENAME_TARGET	The right to invoke path_rename with the file descriptor as the target directory.
RIGHTS_PATH_SYMLINK	The right to invoke path_symlink.
RIGHTS_PATH_UNLINK_FILE	The right to invoke path_unlink_file.
RIGHTS_POLL_FD_READWRITE	If rights::fd_read is set, includes the right to invoke poll_oneoff to subscribe to eventtype::fd_read. If rights::fd_write is set, includes the right to invoke poll_oneoff to subscribe to eventtype::fd_write.
RIGHTS_SOCK_SHUTDOWN	The right to invoke sock_shutdown.
ROFLAGS_RECV_DATA_TRUNCATED	Returned by sock_recv: Message data has been truncated.
SDFLAGS_RD	Disables further receive operations.
SDFLAGS_WR	Disables further send operations.
SIGNAL_ABRT	Process abort signal. Action: Terminates the process.
SIGNAL_ALRM	Alarm clock. Action: Terminates the process.
SIGNAL_BUS	Access to an undefined portion of a memory object. Action: Terminates the process.
SIGNAL_CHLD	Child process terminated, stopped, or continued. Action: Ignored.
SIGNAL_CONT	Continue executing, if stopped. Action: Continues executing, if stopped.
SIGNAL_FPE	Erroneous arithmetic operation. Action: Terminates the process.
SIGNAL_HUP	Hangup. Action: Terminates the process.
SIGNAL_ILL	Illegal instruction. Action: Terminates the process.
SIGNAL_INT	Terminate interrupt signal. Action: Terminates the process.
SIGNAL_KILL	Kill. Action: Terminates the process.
SIGNAL_NONE	No signal. Note that POSIX has special semantics for kill(pid, 0), so this value is reserved.
SIGNAL_PIPE	Write on a pipe with no one to read it. Action: Ignored.
SIGNAL_POLL	I/O possible. Action: Terminates the process.
SIGNAL_PROF	Profiling timer expired. Action: Terminates the process.
SIGNAL_PWR	Power failure. Action: Terminates the process.
SIGNAL_QUIT	Terminal quit signal. Action: Terminates the process.
SIGNAL_SEGV	Invalid memory reference. Action: Terminates the process.
SIGNAL_STOP	Stop executing. Action: Stops executing.
SIGNAL_SYS	Bad system call. Action: Terminates the process.
SIGNAL_TERM	Termination signal. Action: Terminates the process.
SIGNAL_TRAP	Trace/breakpoint trap. Action: Terminates the process.
SIGNAL_TSTP	Terminal stop signal. Action: Stops executing.
SIGNAL_TTIN	Background process attempting read. Action: Stops executing.
SIGNAL_TTOU	Background process attempting write. Action: Stops executing.
SIGNAL_URG	High bandwidth data is available at a socket. Action: Ignored.
SIGNAL_USR1	User-defined signal 1. Action: Terminates the process.
SIGNAL_USR2	User-defined signal 2. Action: Terminates the process.
SIGNAL_VTALRM	Virtual timer expired. Action: Terminates the process.
SIGNAL_WINCH	Window changed. Action: Ignored.
SIGNAL_XCPU	CPU time limit exceeded. Action: Terminates the process.
SIGNAL_XFSZ	File size limit exceeded. Action: Terminates the process.
SUBCLOCKFLAGS_SUBSCRIPTION_CLOCK_ABSTIME	If set, treat the timestamp provided in subscription::u.clock.timeout as an absolute timestamp of clock subscription::u.clock.clock_id. If clear, treat the timestamp provided in subscription::u.clock.timeout relative to the current time value of clock subscription::u.clock.clock_id.
WHENCE_CUR	Seek relative to current position.
WHENCE_END	Seek relative to end-of-file.
WHENCE_SET	Seek relative to start-of-file.

Functions

args_get⚠	Read command-line argument data. The size of the array should match that returned by wasi_args_sizes_get()
args_sizes_get⚠	Return command-line argument data sizes.
clock_res_get⚠	Return the resolution of a clock. Implementations are required to provide a non-zero value for supported clocks. For unsupported clocks, return WASI_EINVAL Note: This is similar to clock_getres in POSIX.
clock_time_get⚠	Return the time value of a clock. Note: This is similar to clock_gettime in POSIX.
environ_get⚠	Read environment variable data. The sizes of the buffers should match that returned by environ.sizes_get().
environ_sizes_get⚠	Return command-line argument data sizes.
fd_advise⚠	Provide file advisory information on a file descriptor. Note: This is similar to posix_fadvise in POSIX.
fd_allocate⚠	Force the allocation of space in a file. Note: This is similar to posix_fallocate in POSIX.
fd_close⚠	Close a file descriptor. Note: This is similar to close in POSIX.
fd_datasync⚠	Synchronize the data of a file to disk. Note: This is similar to fdatasync in POSIX.
fd_fdstat_get⚠	Get the attributes of a file descriptor. Note: This returns similar flags to fsync(fd, F_GETFL) in POSIX, as well as additional fields.
fd_fdstat_set_flags⚠	Adjust the flags associated with a file descriptor. Note: This is similar to fcntl(fd, F_SETFL, flags) in POSIX.
fd_fdstat_set_rights⚠	Adjust the rights associated with a file descriptor. This can only be used to remove rights, and returns ENOTCAPABLE if called in a way that would attempt to add rights
fd_filestat_get⚠	Return the attributes of an open file.
fd_filestat_set_size⚠	Adjust the size of an open file. If this increases the file's size, the extra bytes are filled with zeros. Note: This is similar to ftruncate in POSIX.
fd_filestat_set_times⚠	Adjust the timestamps of an open file or directory. Note: This is similar to futimens in POSIX.
fd_pread⚠	Read from a file descriptor, without using and updating the file descriptor's offset. Note: This is similar to preadv in POSIX.
fd_prestat_dir_name⚠	Return a description of the given preopened file descriptor.
fd_prestat_get⚠	Return a description of the given preopened file descriptor.
fd_pwrite⚠	Write to a file descriptor, without using and updating the file descriptor's offset. Note: This is similar to pwritev in POSIX.
fd_read⚠	Read from a file descriptor. Note: This is similar to readv in POSIX.
fd_readdir⚠	Read directory entries from a directory. When successful, the contents of the output buffer consist of a sequence of directory entries. Each directory entry consists of a dirent_t object, followed by dirent_t::d_namlen bytes holding the name of the directory entry. This function fills the output buffer as much as possible, potentially truncating the last directory entry. This allows the caller to grow its read buffer size in case it's too small to fit a single large directory entry, or skip the oversized directory entry.
fd_renumber⚠	Atomically replace a file descriptor by renumbering another file descriptor. Due to the strong focus on thread safety, this environment does not provide a mechanism to duplicate or renumber a file descriptor to an arbitrary number, like dup2(). This would be prone to race conditions, as an actual file descriptor with the same number could be allocated by a different thread at the same time. This function provides a way to atomically renumber file descriptors, which would disappear if dup2() were to be removed entirely.
fd_seek⚠	Move the offset of a file descriptor. Note: This is similar to lseek in POSIX.
fd_sync⚠	Synchronize the data and metadata of a file to disk. Note: This is similar to fsync in POSIX.
fd_tell⚠	Return the current offset of a file descriptor. Note: This is similar to lseek(fd, 0, SEEK_CUR) in POSIX.
fd_write⚠	Write to a file descriptor. Note: This is similar to writev in POSIX.
path_create_directory⚠	Create a directory. Note: This is similar to mkdirat in POSIX.
path_filestat_get⚠	Return the attributes of a file or directory. Note: This is similar to stat in POSIX.
path_filestat_set_times⚠	Adjust the timestamps of a file or directory. Note: This is similar to utimensat in POSIX.
path_link⚠	Create a hard link. Note: This is similar to linkat in POSIX.
path_open⚠	Open a file or directory. The returned file descriptor is not guaranteed to be the lowest-numbered file descriptor not currently open; it is randomized to prevent applications from depending on making assumptions about indexes, since this is error-prone in multi-threaded contexts. The returned file descriptor is guaranteed to be less than 2**31. Note: This is similar to openat in POSIX.
path_readlink⚠	Read the contents of a symbolic link. Note: This is similar to readlinkat in POSIX.
path_remove_directory⚠	Remove a directory. Return ENOTEMPTY if the directory is not empty. Note: This is similar to unlinkat(fd, path, AT_REMOVEDIR) in POSIX.
path_rename⚠	Rename a file or directory. Note: This is similar to renameat in POSIX.
path_symlink⚠	Create a symbolic link. Note: This is similar to symlinkat in POSIX.
path_unlink_file⚠	Unlink a file. Return EISDIR if the path refers to a directory. Note: This is similar to unlinkat(fd, path, 0) in POSIX.
poll_oneoff⚠	Concurrently poll for the occurrence of a set of events.
proc_exit⚠	Terminate the process normally. An exit code of 0 indicates successful termination of the program. The meanings of other values is dependent on the environment.
proc_raise⚠	Send a signal to the process of the calling thread. Note: This is similar to raise in POSIX.
random_get⚠	Write high-quality random data into a buffer. This function blocks when the implementation is unable to immediately provide sufficient high-quality random data. This function may execute slowly, so when large mounts of random data are required, it's advisable to use this function to seed a pseudo-random number generator, rather than to provide the random data directly.
sched_yield⚠	Temporarily yield execution of the calling thread. Note: This is similar to sched_yield in POSIX.
sock_recv⚠	Receive a message from a socket. Note: This is similar to recv in POSIX, though it also supports reading the data into multiple buffers in the manner of readv.
sock_send⚠	Send a message on a socket. Note: This is similar to send in POSIX, though it also supports writing the data from multiple buffers in the manner of writev.
sock_shutdown⚠	Shut down socket send and receive channels. Note: This is similar to shutdown in POSIX.

Type Definitions

Advice
CiovecArray
Clockid
Device
Dircookie
Dirnamlen
Errno
Eventrwflags
Eventtype
Exitcode
Fd
Fdflags
Filedelta
Filesize
Filetype
Fstflags
Inode
IovecArray
Linkcount
Lookupflags
Oflags
Preopentype
Result
Riflags
Rights
Roflags
Sdflags
Siflags
Signal
Size
Subclockflags
Timestamp
Userdata
Whence

Unions

EventU
PrestatU
SubscriptionU