BufferedInputStream

class BufferedInputStream(**properties: Any)

Superclasses: FilterInputStream, InputStream, Object

Subclasses: DataInputStream

Implemented Interfaces: Seekable

Buffered input stream implements FilterInputStream and provides for buffered reads.

By default, GBufferedInputStream’s buffer size is set at 4 kilobytes.

To create a buffered input stream, use new, or new_sized to specify the buffer’s size at construction.

To get the size of a buffer within a buffered input stream, use get_buffer_size. To change the size of a buffered input stream’s buffer, use set_buffer_size. Note that the buffer’s size cannot be reduced below the size of the data within the buffer.

Constructors

class BufferedInputStream
classmethod new(base_stream: InputStream) → InputStream

Creates a new InputStream from the given base_stream, with a buffer set to the default size (4 kilobytes).

Parameters:

base_stream – a InputStream

classmethod new_sized(base_stream: InputStream, size: int) → InputStream

Creates a new BufferedInputStream from the given base_stream, with a buffer set to size.

Parameters:

Methods

class BufferedInputStream
fill(count: int, cancellable: Cancellable | None = None) → int

Tries to read count bytes from the stream into the buffer. Will block during this read.

If count is zero, returns zero and does nothing. A value of count larger than %G_MAXSSIZE will cause a INVALID_ARGUMENT error.

On success, the number of bytes read into the buffer is returned. It is not an error if this is not the same as the requested size, as it can happen e.g. near the end of a file. Zero is returned on end of file (or if count is zero), but never otherwise.

If count is -1 then the attempted read size is equal to the number of bytes that are required to fill the buffer.

If cancellable is not None, then the operation can be cancelled by triggering the cancellable object from another thread. If the operation was cancelled, the error CANCELLED will be returned. If an operation was partially finished when the operation was cancelled the partial result will be returned, without an error.

On error -1 is returned and error is set accordingly.

For the asynchronous, non-blocking, version of this function, see fill_async().

Parameters:

  • count – the number of bytes that will be read from the stream

  • cancellable – optional Cancellable object, None to ignore

fill_async(count: int, io_priority: int, cancellable: Cancellable | None = None, callback: Callable[[...], None] | None = None, *user_data: Any) → None

Reads data into stream’s buffer asynchronously, up to count size. io_priority can be used to prioritize reads. For the synchronous version of this function, see fill().

If count is -1 then the attempted read size is equal to the number of bytes that are required to fill the buffer.

Parameters:

  • count – the number of bytes that will be read from the stream

  • io_priority – the [I/O priority][io-priority] of the request

  • cancellable – optional Cancellable object

  • callback – a AsyncReadyCallback

  • user_data – a gpointer

fill_finish(result: AsyncResult) → int

Finishes an asynchronous read.

Parameters:

result – a AsyncResult

get_available() → int

Gets the size of the available data within the stream.

get_buffer_size() → int

Gets the size of the input buffer.

peek(buffer: Sequence[int], offset: int) → int

Peeks in the buffer, copying data of size count into buffer, offset offset bytes.

Parameters:

  • buffer – a pointer to an allocated chunk of memory

  • offset – a gsize

peek_buffer() → bytes

Returns the buffer with the currently available bytes. The returned buffer must not be modified and will become invalid when reading from the stream or filling the buffer.

read_byte(cancellable: Cancellable | None = None) → int

Tries to read a single byte from the stream or the buffer. Will block during this read.

On success, the byte read from the stream is returned. On end of stream

-1 is returned but it’s not an exceptional error and error is not set.

If cancellable is not None, then the operation can be cancelled by triggering the cancellable object from another thread. If the operation was cancelled, the error CANCELLED will be returned. If an operation was partially finished when the operation was cancelled the partial result will be returned, without an error.

On error -1 is returned and error is set accordingly.

Parameters:

cancellable – optional Cancellable object, None to ignore

set_buffer_size(size: int) → None

Sets the size of the internal buffer of stream to size, or to the size of the contents of the buffer. The buffer can never be resized smaller than its current contents.

Parameters:

size – a gsize

Properties

class BufferedInputStream
props.buffer_size: int

The size of the backend buffer, in bytes.

Virtual Methods

class BufferedInputStream
do_fill(count: int, cancellable: Cancellable | None = None) → int

Tries to read count bytes from the stream into the buffer. Will block during this read.

If count is zero, returns zero and does nothing. A value of count larger than %G_MAXSSIZE will cause a INVALID_ARGUMENT error.

On success, the number of bytes read into the buffer is returned. It is not an error if this is not the same as the requested size, as it can happen e.g. near the end of a file. Zero is returned on end of file (or if count is zero), but never otherwise.

If count is -1 then the attempted read size is equal to the number of bytes that are required to fill the buffer.

If cancellable is not None, then the operation can be cancelled by triggering the cancellable object from another thread. If the operation was cancelled, the error CANCELLED will be returned. If an operation was partially finished when the operation was cancelled the partial result will be returned, without an error.

On error -1 is returned and error is set accordingly.

For the asynchronous, non-blocking, version of this function, see fill_async().

Parameters:

  • count – the number of bytes that will be read from the stream

  • cancellable – optional Cancellable object, None to ignore

do_fill_async(count: int, io_priority: int, cancellable: Cancellable | None = None, callback: Callable[[...], None] | None = None, *user_data: Any) → None

Reads data into stream’s buffer asynchronously, up to count size. io_priority can be used to prioritize reads. For the synchronous version of this function, see fill().

If count is -1 then the attempted read size is equal to the number of bytes that are required to fill the buffer.

Parameters:

  • count – the number of bytes that will be read from the stream

  • io_priority – the [I/O priority][io-priority] of the request

  • cancellable – optional Cancellable object

  • callback – a AsyncReadyCallback

  • user_data – a gpointer

do_fill_finish(result: AsyncResult) → int

Finishes an asynchronous read.

Parameters:

result – a AsyncResult

Fields

class BufferedInputStream
parent_instance
priv