pub struct ReadPos<P> where
P: PosRead, { /* fields omitted */ }
Re-implements Read
and Seek
over PosRead
using only positioned
reads, and by maintaining an instance independent position.
PosRead
is implemented for any Borrow<File>
so
this can own via ReadPos<File>
or use a shared reference, as in
ReadPos<&File>
or ReadPos<Arc<File>>
.
A fixed length
is passed on construction and used solely to interpret
SeekFrom::End
. Reads are not constrained by this length. The length is
neither checked against nor updated from the inner PosRead
(for example
via file metadata) and could deviate if concurrent writes or truncation is
possible. Reads beyond the end of the inner PosRead
will return 0
length. Seeking past the end is allowed by the platforms for File
, and
is also allowed for ReadPos
.
New instance for PosRead
and fixed length. The initial position is
the start (index 0).
Return the length as provided on construction. This may differ from
the inner PosRead
length.
Return true
if length is 0.
Return the current instance position. This is a convenience shorthand
for seek(SeekFrom::Current(0))
, is infallable, and does not require
a mutable reference.
Return a new and independent ReadSlice
by clone of the inner
PosRead
, for the range of byte offsets start..end
, and positoned
at start. This implementation panics if start is greater than
end. Note that the end parameter is not checked against the length of
self as passed on construction.
Formats the value using the given formatter. Read more
Return a new, independent ReadPos
by clone of the inner PosRead
,
with the same length as self, and at position 0.
Performs copy-assignment from source
. Read more
Read bytes, starting at the specified offset, into the specified buffer and return the number of bytes read. The offset is from the start of the underlying file or file range. Reads beyond the end of available bytes will return 0 length. The position of the underlying file pointer (aka cursor) is not used. It is platform dependent whether the underlying file pointer is modified by this operation. Read more
Pull some bytes from this source into the specified buffer, returning how many bytes were read. Read more
🔬 This is a nightly-only experimental API. (read_initializer
)
Determines if this Read
er can work with buffers of uninitialized memory. Read more
Read all bytes until EOF in this source, placing them into buf
. Read more
Read all bytes until EOF in this source, appending them to buf
. Read more
Read the exact number of bytes required to fill buf
. Read more
Creates a "by reference" adaptor for this instance of Read
. Read more
Transforms this Read
instance to an [Iterator
] over its bytes. Read more
Deprecated since 1.27.0
: Use str::from_utf8 instead:
https://doc.rust-lang.org/nightly/std/str/struct.Utf8Error.html#examples
🔬 This is a nightly-only experimental API. (io
)
the semantics of a partial read/write of where errors happen is currently unclear and may change
Transforms this Read
instance to an [Iterator
] over [char
]s. Read more
Creates an adaptor which will chain this stream with another. Read more
Creates an adaptor which will read at most limit
bytes from it. Read more
Seek to an offset, in bytes, in a stream. Read more