Expand description
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
Structs
Constants
The application expects that it will not access the specified data in the near future.
The application expects to access the specified data once and then not reuse it thereafter.
The application has no advice to give on its behavior with respect to the specified data.
The application expects to access the specified data in a random order.
The application expects to access the specified data sequentially from lower offsets to higher offsets.
The application expects to access the specified data in the near future.
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.
The CPU-time clock associated with the current process.
The clock measuring real time. Time value zero corresponds with 1970-01-01T00:00:00Z.
The CPU-time clock associated with the current thread.
Special Dircookie value indicating the start of a directory.
Argument list too long.
Permission denied.
Address in use.
Address not available.
Address family not supported.
Resource unavailable, or operation would block.
Connection already in progress.
Bad file descriptor.
Bad message.
Device or resource busy.
Operation canceled.
No child processes.
Connection aborted.
Connection refused.
Connection reset.
Resource deadlock would occur.
Destination address required.
Mathematics argument out of domain of function.
Reserved.
File exists.
Bad address.
File too large.
Host is unreachable.
Identifier removed.
Illegal byte sequence.
Operation in progress.
Interrupted function.
Invalid argument.
I/O error.
Socket is connected.
Is a directory.
Too many levels of symbolic links.
File descriptor value too large.
Too many links.
Message too large.
Reserved.
Filename too long.
Network is down.
Connection aborted by network.
Network unreachable.
Too many files open in system.
No buffer space available.
No such device.
No such file or directory.
Executable file format error.
No locks available.
Reserved.
Not enough space.
No message of the desired type.
Protocol not available.
No space left on device.
Function not supported.
Extension: Capabilities insufficient.
The socket is not connected.
Not a directory or a symbolic link to a directory.
Directory not empty.
State not recoverable.
Not a socket.
Not supported, or operation not supported on socket.
Inappropriate I/O control operation.
No such device or address.
Value too large to be stored in data type.
Previous owner died.
Operation not permitted.
Broken pipe.
Protocol error.
Protocol not supported.
Protocol wrong type for socket.
Result too large.
Read-only file system.
Invalid seek.
No such process.
Reserved.
No error occurred. System call completed successfully.
Connection timed out.
Text file busy.
Cross-device link.
The peer of this socket has closed or disconnected.
The time value of clock subscription_clock::id has
reached timestamp subscription_clock::timeout.
File descriptor subscription_fd_readwrite::file_descriptor has data
available for reading. This event always triggers for regular files.
File descriptor subscription_fd_readwrite::file_descriptor has capacity
available for writing. This event always triggers for regular files.
Append mode: Data written to the file is always appended to the file’s end.
Write according to synchronized I/O data integrity completion. Only the data stored in the file is synchronized.
Non-blocking mode.
Synchronized read I/O operations.
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.
The “standard error” descriptor number.
The “standard input” descriptor number.
The “standard output” descriptor number.
The file descriptor or file refers to a block device inode.
The file descriptor or file refers to a character device inode.
The file descriptor or file refers to a directory inode.
The file descriptor or file refers to a regular file inode.
The file descriptor or file refers to a datagram socket.
The file descriptor or file refers to a byte-stream socket.
The file refers to a symbolic link inode.
The type of the file descriptor or file is unknown or is different from any of the other types specified.
Adjust the last data access timestamp to the value stored in filestat::atim.
Adjust the last data access timestamp to the time of clock clockid::realtime.
Adjust the last data modification timestamp to the value stored in filestat::mtim.
Adjust the last data modification timestamp to the time of clock clockid::realtime.
As long as the resolved path corresponds to a symbolic link, it is expanded.
Create file if it does not exist.
Fail if not a directory.
Fail if file already exists.
Truncate file to size 0.
A pre-opened directory.
Returns the message without removing it from the socket’s receive queue.
On byte-stream sockets, block until the full amount of data can be returned.
The right to invoke fd_advise.
The right to invoke fd_allocate.
The right to invoke fd_datasync.
If path_open is set, includes the right to invoke
path_open with fdflags::dsync.
The right to invoke fd_fdstat_set_flags.
The right to invoke fd_filestat_get.
The right to invoke fd_filestat_set_size.
The right to invoke fd_filestat_set_times.
The right to invoke fd_read and sock_recv.
If rights::fd_seek is set, includes the right to invoke fd_pread.
The right to invoke fd_readdir.
The right to invoke fd_seek. This flag implies rights::fd_tell.
The right to invoke fd_sync.
If path_open is set, includes the right to invoke
path_open with fdflags::rsync and fdflags::dsync.
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.
The right to invoke fd_write and sock_send.
If rights::fd_seek is set, includes the right to invoke fd_pwrite.
The right to invoke path_create_directory.
If path_open is set, the right to invoke path_open with oflags::creat.
The right to invoke path_filestat_get.
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.
The right to invoke path_filestat_set_times.
The right to invoke path_link with the file descriptor as the
source directory.
The right to invoke path_link with the file descriptor as the
target directory.
The right to invoke path_open.
The right to invoke path_readlink.
The right to invoke path_remove_directory.
The right to invoke path_rename with the file descriptor as the source directory.
The right to invoke path_rename with the file descriptor as the target directory.
The right to invoke path_symlink.
The right to invoke path_unlink_file.
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.
The right to invoke sock_accept.
The right to invoke sock_shutdown.
Returned by sock_recv: Message data has been truncated.
Disables further receive operations.
Disables further send operations.
Process abort signal. Action: Terminates the process.
Alarm clock. Action: Terminates the process.
Access to an undefined portion of a memory object. Action: Terminates the process.
Child process terminated, stopped, or continued. Action: Ignored.
Continue executing, if stopped. Action: Continues executing, if stopped.
Erroneous arithmetic operation. Action: Terminates the process.
Hangup. Action: Terminates the process.
Illegal instruction. Action: Terminates the process.
Terminate interrupt signal. Action: Terminates the process.
Kill. Action: Terminates the process.
No signal. Note that POSIX has special semantics for kill(pid, 0),
so this value is reserved.
Write on a pipe with no one to read it. Action: Ignored.
I/O possible. Action: Terminates the process.
Profiling timer expired. Action: Terminates the process.
Power failure. Action: Terminates the process.
Terminal quit signal. Action: Terminates the process.
Invalid memory reference. Action: Terminates the process.
Stop executing. Action: Stops executing.
Bad system call. Action: Terminates the process.
Termination signal. Action: Terminates the process.
Trace/breakpoint trap. Action: Terminates the process.
Terminal stop signal. Action: Stops executing.
Background process attempting read. Action: Stops executing.
Background process attempting write. Action: Stops executing.
High bandwidth data is available at a socket. Action: Ignored.
User-defined signal 1. Action: Terminates the process.
User-defined signal 2. Action: Terminates the process.
Virtual timer expired. Action: Terminates the process.
Window changed. Action: Ignored.
CPU time limit exceeded. Action: Terminates the process.
File size limit exceeded. Action: Terminates the process.
If set, treat the timestamp provided in
subscription_clock::timeout as an absolute timestamp of clock
subscription_clock::id. If clear, treat the timestamp
provided in subscription_clock::timeout relative to the
current time value of clock subscription_clock::id.
Seek relative to current position.
Seek relative to end-of-file.
Seek relative to start-of-file.
Functions
Read command-line argument data.
The size of the array should match that returned by args_sizes_get.
Each argument is expected to be \0 terminated.
Return command-line argument data sizes.
Return the resolution of a clock.
Implementations are required to provide a non-zero value for supported clocks. For unsupported clocks,
return errno::inval.
Note: This is similar to clock_getres in POSIX.
Return the time value of a clock.
Note: This is similar to clock_gettime in POSIX.
Read environment variable data.
The sizes of the buffers should match that returned by environ_sizes_get.
Key/value pairs are expected to be joined with =s, and terminated with \0s.
Return environment variable data sizes.
Provide file advisory information on a file descriptor.
Note: This is similar to posix_fadvise in POSIX.
Force the allocation of space in a file.
Note: This is similar to posix_fallocate in POSIX.
Synchronize the data of a file to disk.
Note: This is similar to fdatasync in POSIX.
Get the attributes of a file descriptor.
Note: This returns similar flags to fsync(fd, F_GETFL) in POSIX, as well as additional fields.
Adjust the flags associated with a file descriptor.
Note: This is similar to fcntl(fd, F_SETFL, flags) in POSIX.
Adjust the rights associated with a file descriptor.
This can only be used to remove rights, and returns errno::notcapable if called in a way that would attempt to add rights
Return the attributes of an open file.
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.
Adjust the timestamps of an open file or directory.
Note: This is similar to futimens in POSIX.
Read from a file descriptor, without using and updating the file descriptor’s offset.
Note: This is similar to preadv in POSIX.
Return a description of the given preopened file descriptor.
Return a description of the given preopened file descriptor.
Write to a file descriptor, without using and updating the file descriptor’s offset.
Note: This is similar to pwritev in POSIX.
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 object,
followed by dirent::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.
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.
Synchronize the data and metadata of a file to disk.
Note: This is similar to fsync in POSIX.
Return the current offset of a file descriptor.
Note: This is similar to lseek(fd, 0, SEEK_CUR) in POSIX.
Create a directory.
Note: This is similar to mkdirat in POSIX.
Return the attributes of a file or directory.
Note: This is similar to stat in POSIX.
Adjust the timestamps of a file or directory.
Note: This is similar to utimensat in POSIX.
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.
Read the contents of a symbolic link.
Note: This is similar to readlinkat in POSIX.
Remove a directory.
Return errno::notempty if the directory is not empty.
Note: This is similar to unlinkat(fd, path, AT_REMOVEDIR) in POSIX.
Rename a file or directory.
Note: This is similar to renameat in POSIX.
Create a symbolic link.
Note: This is similar to symlinkat in POSIX.
Unlink a file.
Return errno::isdir if the path refers to a directory.
Note: This is similar to unlinkat(fd, path, 0) in POSIX.
Concurrently poll for the occurrence of a set of events.
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.
Send a signal to the process of the calling thread.
Note: This is similar to raise in POSIX.
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.
Temporarily yield execution of the calling thread.
Note: This is similar to sched_yield in POSIX.
Accept a new incoming connection.
Note: This is similar to accept in POSIX.
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.
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.
Shut down socket send and receive channels.
Note: This is similar to shutdown in POSIX.