Gio::InputStream Class Reference
[Stream Classes]

Base class for implementing streaming input. More...

Inherits Glib::Object.

Inherited by Gio::FileInputStream, Gio::FilterInputStream, Gio::MemoryInputStream, and Gio::UnixInputStream.

Collaboration diagram for Gio::InputStream:
Collaboration graph
[legend]

List of all members.

Public Member Functions

virtual ~InputStream ()
GInputStream* gobj ()
 Provides access to the underlying C GObject.
const GInputStream* gobj () const
 Provides access to the underlying C GObject.
GInputStream* gobj_copy ()
 Provides access to the underlying C instance. The caller is responsible for unrefing it. Use when directly setting fields in structs.
gssize read (void* buffer, gsize count, const Glib::RefPtr< Cancellable >& cancellable)
 Tries to read count bytes from the stream into the buffer starting at buffer.
gssize read (void* buffer, gsize count)
 Tries to read count bytes from the stream into the buffer starting at buffer.
bool read_all (void* buffer, gsize count, gsize& bytes_read, const Glib::RefPtr< Cancellable >& cancellable)
 Tries to read count bytes from the stream into the buffer starting at buffer.
bool read_all (void* buffer, gsize count, gsize& bytes_read)
 Tries to read count bytes from the stream into the buffer starting at buffer.
gssize skip (gsize count, const Glib::RefPtr< Cancellable >& cancellable)
 Tries to skip count bytes from the stream.
gssize skip (gsize count)
 Tries to skip count bytes from the stream.
bool close (const Glib::RefPtr< Cancellable >& cancellable)
 Closes the stream, releasing resources related to it.
bool close ()
 Closes the stream, releasing resources related to it.
void read_async (void* buffer, gsize count, const SlotAsyncReady&slot, const Glib::RefPtr< Cancellable >& cancellable, int io_priority=Glib::PRIORITY_DEFAULT)
 Request an asynchronous read of count bytes from the stream into the buffer starting at buffer.
void read_async (void* buffer, gsize count, const SlotAsyncReady&slot, int io_priority=Glib::PRIORITY_DEFAULT)
 Request an asynchronous read of count bytes from the stream into the buffer starting at buffer.
gssize read_finish (const Glib::RefPtr< AsyncResult >& result)
 Finishes an asynchronous stream read operation.
void skip_async (gsize count, const SlotAsyncReady&slot, const Glib::RefPtr< Cancellable >& cancellable, int io_priority=Glib::PRIORITY_DEFAULT)
 Request an asynchronous skip of count bytes from the stream into the buffer starting at buffer.
void skip_async (gsize count, const SlotAsyncReady&slot, int io_priority=Glib::PRIORITY_DEFAULT)
 Request an asynchronous skip of count bytes from the stream into the buffer starting at buffer.
gssize skip_finish (const Glib::RefPtr< AsyncResult >& result)
 Finishes a stream skip operation.
void close_async (const SlotAsyncReady&slot, const Glib::RefPtr< Cancellable >& cancellable, int io_priority=Glib::PRIORITY_DEFAULT)
 Requests an asynchronous closes of the stream, releasing resources related to it.
void close_async (const SlotAsyncReady&slot, int io_priority=Glib::PRIORITY_DEFAULT)
 Requests an asynchronous closes of the stream, releasing resources related to it.
gboolean close_finish (const Glib::RefPtr< AsyncResult >& result)
 Finishes closing a stream asynchronously, started from g_input_stream_close_async().

Related Functions

(Note that these are not member functions.)



Glib::RefPtr< Gio::InputStreamwrap (GInputStream* object, bool take_copy=false)
 A Glib::wrap() method for this object.

Detailed Description

Base class for implementing streaming input.

Since glibmm 2.16:

Constructor & Destructor Documentation

virtual Gio::InputStream::~InputStream (  )  [virtual]

Member Function Documentation

bool Gio::InputStream::close (  ) 

Closes the stream, releasing resources related to it.

Once the stream is closed, all other operations will throw a Gio::Error with CLOSED. Closing a stream multiple times will not return an error.

Streams will be automatically closed when the last reference is dropped, but you might want to call this make sure resources are released as early as possible.

Some streams might keep the backing store of the stream (e.g. a file descriptor) open after the stream is closed. See the documentation for the individual stream for details.

On failure the first error that happened will be reported, but the close operation will finish as much as possible. A stream that failed to close will still throw a Gio::Error with CLOSED for all operations. Still, it is important to check and report the error to the user.

Returns:
true on success, false on failure.
bool Gio::InputStream::close ( const Glib::RefPtr< Cancellable >&  cancellable  ) 

Closes the stream, releasing resources related to it.

Once the stream is closed, all other operations will throw a Gio::Error with CLOSED. Closing a stream multiple times will not return an error.

Streams will be automatically closed when the last reference is dropped, but you might want to call this function to make sure resources are released as early as possible.

Some streams might keep the backing store of the stream (e.g. a file descriptor) open after the stream is closed. See the documentation for the individual stream for details.

On failure the first error that happened will be reported, but the close operation will finish as much as possible. A stream that failed to close will still throw a Gio::Error with CLOSED for all operations. Still, it is important to check and report the error to the user.

The operation can be cancelled by triggering the cancellable object from another thread. If the operation was cancelled, a Gio::Error will be thrown with CANCELLED. Cancelling a close will still leave the stream closed, but some streams can use a faster close that doesn't block to e.g. check errors.

Parameters:
cancellable Cancellable object.
Returns:
true on success, false on failure.
void Gio::InputStream::close_async ( const SlotAsyncReady slot,
int  io_priority = Glib::PRIORITY_DEFAULT 
)

Requests an asynchronous closes of the stream, releasing resources related to it.

When the operation is finished slot will be called. You can then call close_finish() to get the result of the operation.

For behaviour details see close().

The asyncronous methods have a default fallback that uses threads to implement asynchronicity, so they are optional for inheriting classes. However, if you override one you must override all.

Parameters:
slot Callback to call when the request is satisfied.
io_priority The I/O priority of the request.
void Gio::InputStream::close_async ( const SlotAsyncReady slot,
const Glib::RefPtr< Cancellable >&  cancellable,
int  io_priority = Glib::PRIORITY_DEFAULT 
)

Requests an asynchronous closes of the stream, releasing resources related to it.

When the operation is finished slot will be called. You can then call close_finish() to get the result of the operation.

For behaviour details see close().

The asyncronous methods have a default fallback that uses threads to implement asynchronicity, so they are optional for inheriting classes. However, if you override one you must override all.

Parameters:
slot Callback to call when the request is satisfied.
cancellable A Cancellable object.
io_priority The I/O priority of the request.
gboolean Gio::InputStream::close_finish ( const Glib::RefPtr< AsyncResult >&  result  ) 

Finishes closing a stream asynchronously, started from g_input_stream_close_async().

Parameters:
result A AsyncResult.
Returns:
true if the stream was closed successfully.
const GInputStream* Gio::InputStream::gobj (  )  const [inline]

Provides access to the underlying C GObject.

Reimplemented from Glib::ObjectBase.

Reimplemented in Gio::BufferedInputStream, Gio::DataInputStream, Gio::FileInputStream, Gio::FilterInputStream, Gio::MemoryInputStream, and Gio::UnixInputStream.

GInputStream* Gio::InputStream::gobj (  )  [inline]

Provides access to the underlying C GObject.

Reimplemented from Glib::ObjectBase.

Reimplemented in Gio::BufferedInputStream, Gio::DataInputStream, Gio::FileInputStream, Gio::FilterInputStream, Gio::MemoryInputStream, and Gio::UnixInputStream.

GInputStream* Gio::InputStream::gobj_copy (  ) 

Provides access to the underlying C instance. The caller is responsible for unrefing it. Use when directly setting fields in structs.

Reimplemented in Gio::BufferedInputStream, Gio::DataInputStream, Gio::FileInputStream, Gio::FilterInputStream, Gio::MemoryInputStream, and Gio::UnixInputStream.

gssize Gio::InputStream::read ( void *  buffer,
gsize  count 
)

Tries to read count bytes from the stream into the buffer starting at buffer.

Will block during this read.

If count is zero returns zero and does nothing. A value of count larger than MAXSSIZE will cause a Gio::Error with INVALID_ARGUMENT to be thrown.

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.

On error -1 is returned.

Parameters:
buffer A buffer to read data into (which should be at least count bytes long).
count The number of bytes that will be read from the stream.
Returns:
Number of bytes read, or -1 on error.
gssize Gio::InputStream::read ( void *  buffer,
gsize  count,
const Glib::RefPtr< Cancellable >&  cancellable 
)

Tries to read count bytes from the stream into the buffer starting at buffer.

Will block during this read.

If count is zero returns zero and does nothing. A value of count larger than MAXSSIZE will cause a Gio::Error with INVALID_ARGUMENT to be thrown.

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.

The operation can be cancelled by triggering the cancellable object from another thread. If the operation was cancelled, a Gio::Error will be thrown with CANCELLED. If an operation was partially finished when the operation was cancelled the partial result will be returned, without an error.

Parameters:
buffer A buffer to read data into (which should be at least count bytes long).
count The number of bytes that will be read from the stream.
cancellable Cancellable object.
Returns:
Number of bytes read, or -1 on error.
bool Gio::InputStream::read_all ( void *  buffer,
gsize  count,
gsize &  bytes_read 
)

Tries to read count bytes from the stream into the buffer starting at buffer.

Will block during this read.

This function is similar to read(), except it tries to read as many bytes as requested, only stopping on an error or end of stream.

On a successful read of count bytes, or if we reached the end of the stream, true is returned, and bytes_read is set to the number of bytes read into buffer .

If there is an error during the operation false is returned and a Gio::Error is thrown to indicate the error status, bytes_read is updated to contain the number of bytes read into buffer before the error occured.

Parameters:
buffer A buffer to read data into (which should be at least count bytes long).
count The number of bytes that will be read from the stream.
bytes_read Location to store the number of bytes that was read from the stream.
Returns:
true on success, false if there was an error.
bool Gio::InputStream::read_all ( void *  buffer,
gsize  count,
gsize &  bytes_read,
const Glib::RefPtr< Cancellable >&  cancellable 
)

Tries to read count bytes from the stream into the buffer starting at buffer.

Will block during this read.

This function is similar to g_input_stream_read(), except it tries to read as many bytes as requested, only stopping on an error or end of stream.

On a successful read of count bytes, or if we reached the end of the stream, true is returned, and bytes_read is set to the number of bytes read into buffer.

If there is an error during the operation false is returned and error is set to indicate the error status, bytes_read is updated to contain the number of bytes read into buffer before the error occurred.

Parameters:
buffer A buffer to read data into (which should be at least count bytes long).
count The number of bytes that will be read from the stream.
bytes_read Location to store the number of bytes that was read from the stream.
cancellable Optional Cancellable object, 0 to ignore.
Returns:
true on success, false if there was an error.
void Gio::InputStream::read_async ( void *  buffer,
gsize  count,
const SlotAsyncReady slot,
int  io_priority = Glib::PRIORITY_DEFAULT 
)

Request an asynchronous read of count bytes from the stream into the buffer starting at buffer.

When the operation is finished slot will be called. You can then call read_finish() to get the result of the operation.

During an async request no other sync and async calls are allowed, and will result in a Gio::Error with PENDING being thrown.

A value of count larger than MAXSSIZE will cause a Gio::Error with INVALID_ARGUMENT to be thrown.

On success, the number of bytes read into the buffer will be passed to the slot callback. 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, but generally we try to read as many bytes as requested. Zero is returned on end of file (or if count is zero), but never otherwise.

Any outstanding i/o request with higher priority (lower numerical value) will be executed before an outstanding request with lower priority. Default priority is PRIORITY_DEFAULT.

The asyncronous methods have a default fallback that uses threads to implement asynchronicity, so they are optional for inheriting classes. However, if you override one you must override all.

Parameters:
buffer A buffer to read data into (which should be at least count bytes long).
count The number of bytes that will be read from the stream.
slot Callback to call when the request is satisfied.
io_priority The I/O priority of the request.
void Gio::InputStream::read_async ( void *  buffer,
gsize  count,
const SlotAsyncReady slot,
const Glib::RefPtr< Cancellable >&  cancellable,
int  io_priority = Glib::PRIORITY_DEFAULT 
)

Request an asynchronous read of count bytes from the stream into the buffer starting at buffer.

When the operation is finished slot will be called. You can then call read_finish() to get the result of the operation.

During an async request no other sync and async calls are allowed, and will result in Gio::Error with PENDING being thrown.

A value of count larger than MAXSSIZE will cause a Gio::Error with INVALID_ARGUMENT to be thrown.

On success, the number of bytes read into the buffer will be passed to the slot callback. 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, but generally we try to read as many bytes as requested. Zero is returned on end of file (or if count is zero), but never otherwise.

Any outstanding i/o request with higher priority (lower numerical value) will be executed before an outstanding request with lower priority. Default priority is PRIORITY_DEFAULT.

The asyncronous methods have a default fallback that uses threads to implement asynchronicity, so they are optional for inheriting classes. However, if you override one you must override all.

Parameters:
buffer A buffer to read data into (which should be at least count bytes long).
count The number of bytes that will be read from the stream.
slot Callback to call when the request is satisfied.
cancellable A Cancellable object.
io_priority The I/O priority of the request.
gssize Gio::InputStream::read_finish ( const Glib::RefPtr< AsyncResult >&  result  ) 

Finishes an asynchronous stream read operation.

Parameters:
result A AsyncResult.
Returns:
Number of bytes read in, or -1 on error.
gssize Gio::InputStream::skip ( gsize  count  ) 

Tries to skip count bytes from the stream.

Will block during the operation.

This is identical to read(), from a behaviour standpoint, but the bytes that are skipped are not returned to the user. Some streams have an implementation that is more efficient than reading the data.

This function is optional for inherited classes, as the default implementation emulates it using read.

Parameters:
count The number of bytes that will be skipped from the stream.
Returns:
Number of bytes skipped, or -1 on error.
gssize Gio::InputStream::skip ( gsize  count,
const Glib::RefPtr< Cancellable >&  cancellable 
)

Tries to skip count bytes from the stream.

Will block during the operation.

This is identical to g_input_stream_read(), from a behaviour standpoint, but the bytes that are skipped are not returned to the user. Some streams have an implementation that is more efficient than reading the data.

This function is optional for inherited classes, as the default implementation emulates it using read.

The operation can be cancelled by triggering the cancellable object from another thread. If the operation was cancelled, a Gio::Error will be thrown with CANCELLED. If an operation was partially finished when the operation was cancelled the partial result will be returned, without an error.

Parameters:
count The number of bytes that will be skipped from the stream.
cancellable Cancellable object.
Returns:
Number of bytes skipped, or -1 on error.
void Gio::InputStream::skip_async ( gsize  count,
const SlotAsyncReady slot,
int  io_priority = Glib::PRIORITY_DEFAULT 
)

Request an asynchronous skip of count bytes from the stream into the buffer starting at buffer.

When the operation is finished slot will be called. You can then call skip_finish() to get the result of the operation.

During an async request no other sync and async calls are allowed, and will result in Gio::Error with PENDING being thrown.

A value of count larger than MAXSSIZE will cause a Gio::Error with INVALID_ARGUMENT to be thrown.

On success, the number of bytes skipped will be passed to the callback. 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, but generally we try to skip as many bytes as requested. Zero is returned on end of file (or if count is zero), but never otherwise.

Any outstanding i/o request with higher priority (lower numerical value) will be executed before an outstanding request with lower priority. Default priority is PRIORITY_DEFAULT.

The asyncronous methods have a default fallback that uses threads to implement asynchronicity, so they are optional for inheriting classes. However, if you override one you must override all.

Parameters:
count The number of bytes that will be skipped from the stream.
slot Callback to call when the request is satisfied.
io_priority The I/O priority of the request.
void Gio::InputStream::skip_async ( gsize  count,
const SlotAsyncReady slot,
const Glib::RefPtr< Cancellable >&  cancellable,
int  io_priority = Glib::PRIORITY_DEFAULT 
)

Request an asynchronous skip of count bytes from the stream into the buffer starting at buffer.

When the operation is finished slot will be called. You can then call skip_finish() to get the result of the operation.

During an async request no other sync and async calls are allowed, and will result in Gio::Error with PENDING being thrown.

A value of count larger than MAXSSIZE will cause a Gio::Error with INVALID_ARGUMENT to be thrown.

On success, the number of bytes skipped will be passed to the callback. 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, but generally we try to skip as many bytes as requested. Zero is returned on end of file (or if count is zero), but never otherwise.

Any outstanding i/o request with higher priority (lower numerical value) will be executed before an outstanding request with lower priority. Default priority is PRIORITY_DEFAULT.

The asyncronous methods have a default fallback that uses threads to implement asynchronicity, so they are optional for inheriting classes. However, if you override one you must override all.

Parameters:
count The number of bytes that will be skipped from the stream.
slot Callback to call when the request is satisfied.
cancellable A Cancellable object.
io_priority The I/O priority of the request.
gssize Gio::InputStream::skip_finish ( const Glib::RefPtr< AsyncResult >&  result  ) 

Finishes a stream skip operation.

Parameters:
result A AsyncResult.
Returns:
The size of the bytes skipped, or -1 on error.

Friends And Related Function Documentation

Glib::RefPtr< Gio::InputStream > wrap ( GInputStream *  object,
bool  take_copy = false 
) [related]

A Glib::wrap() method for this object.

Parameters:
object The C instance.
take_copy False if the result should take ownership of the C instance. True if it should take a new copy or ref.
Returns:
A C++ instance that wraps this C instance.

The documentation for this class was generated from the following file:

Generated on Mon Sep 21 09:04:28 2009 for glibmm by  doxygen 1.6.1