Struct rusqlite::blob::Blob

pub struct Blob<'conn> { /* private fields */ }

Handle to an open BLOB.

Implementations

impl<'conn> Blob<'conn>

pub fn reopen(&mut self, row: i64) -> Result<()>

Move a BLOB handle to a new row.

Failure

Will return Err if the underlying SQLite BLOB reopen call fails.

pub fn size(&self) -> i32

Return the size in bytes of the BLOB.

pub fn close(self) -> Result<()>

Close a BLOB handle.

Calling close explicitly is not required (the BLOB will be closed when the Blob is dropped), but it is available so you can get any errors that occur.

Failure

Will return Err if the underlying SQLite close call fails.

Trait Implementations

impl<'conn> Drop for Blob<'conn>

fn drop(&mut self)

Executes the destructor for this type.

impl<'conn> Read for Blob<'conn>

fn read(&mut self, buf: &mut [u8]) -> Result<usize>

Read data from a BLOB incrementally. Will return Ok(0) if the end of the blob has been reached.

Failure

Will return Err if the underlying SQLite read call fails.

fn read_vectored(&mut self, bufs: &mut [IoSliceMut<'_>]) -> Result<usize, Error>

Like read, except that it reads into a slice of buffers.

fn is_read_vectored(&self) -> bool

🔬This is a nightly-only experimental API. (can_vector)

Determines if this Reader has an efficient read_vectored implementation.

fn read_to_end(&mut self, buf: &mut Vec<u8, Global>) -> Result<usize, Error>

Read all bytes until EOF in this source, placing them into buf.

fn read_to_string(&mut self, buf: &mut String) -> Result<usize, Error>

Read all bytes until EOF in this source, appending them to buf.

fn read_exact(&mut self, buf: &mut [u8]) -> Result<(), Error>

Read the exact number of bytes required to fill buf.

fn read_buf(&mut self, buf: BorrowedCursor<'_>) -> Result<(), Error>

🔬This is a nightly-only experimental API. (read_buf)

Pull some bytes from this source into the specified buffer.

fn read_buf_exact(&mut self, cursor: BorrowedCursor<'_>) -> Result<(), Error>

🔬This is a nightly-only experimental API. (read_buf)

Read the exact number of bytes required to fill cursor.

fn by_ref(&mut self) -> &mut Selfwhere
    Self: Sized,

Creates a “by reference” adaptor for this instance of Read.

fn bytes(self) -> Bytes<Self>where
    Self: Sized,

Transforms this Read instance to an Iterator over its bytes.

fn chain<R>(self, next: R) -> Chain<Self, R>where
    R: Read,
    Self: Sized,

Creates an adapter which will chain this stream with another.

fn take(self, limit: u64) -> Take<Self>where
    Self: Sized,

Creates an adapter which will read at most limit bytes from it.

impl<'conn> Seek for Blob<'conn>

fn seek(&mut self, pos: SeekFrom) -> Result<u64>

Seek to an offset, in bytes, in BLOB.

fn rewind(&mut self) -> Result<(), Error>

Rewind to the beginning of a stream.

fn stream_len(&mut self) -> Result<u64, Error>

🔬This is a nightly-only experimental API. (seek_stream_len)

Returns the length of this stream (in bytes).

fn stream_position(&mut self) -> Result<u64, Error>

Returns the current seek position from the start of the stream.

impl<'conn> Write for Blob<'conn>

fn write(&mut self, buf: &[u8]) -> Result<usize>

Write data into a BLOB incrementally. Will return Ok(0) if the end of the blob has been reached; consider using Write::write_all(buf) if you want to get an error if the entirety of the buffer cannot be written.

This function may only modify the contents of the BLOB; it is not possible to increase the size of a BLOB using this API.

Failure

Will return Err if the underlying SQLite write call fails.

fn flush(&mut self) -> Result<()>

Flush this output stream, ensuring that all intermediately buffered contents reach their destination.

fn write_vectored(&mut self, bufs: &[IoSlice<'_>]) -> Result<usize, Error>

Like write, except that it writes from a slice of buffers.

fn is_write_vectored(&self) -> bool

🔬This is a nightly-only experimental API. (can_vector)

Determines if this Writer has an efficient write_vectored implementation.

fn write_all(&mut self, buf: &[u8]) -> Result<(), Error>

Attempts to write an entire buffer into this writer.

fn write_all_vectored(&mut self, bufs: &mut [IoSlice<'_>]) -> Result<(), Error>

🔬This is a nightly-only experimental API. (write_all_vectored)

Attempts to write multiple buffers into this writer.

fn write_fmt(&mut self, fmt: Arguments<'_>) -> Result<(), Error>

Writes a formatted string into this writer, returning any error encountered.

fn by_ref(&mut self) -> &mut Selfwhere
    Self: Sized,

Creates a “by reference” adapter for this instance of Write.