ACE
6.1.0
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This class is a factory for starting off asynchronous reads on a file. This class forwards all methods to its implementation class. More...
#include <Asynch_IO.h>
Classes | |
class | Result |
This is that class which will be passed back to the {handler} when the asynchronous read completes. This class forwards all the methods to the implementation class. More... | |
Public Member Functions | |
ACE_Asynch_Read_File (void) | |
A do nothing constructor. | |
virtual | ~ACE_Asynch_Read_File (void) |
Destructor. | |
int | open (ACE_Handler &handler, ACE_HANDLE handle=ACE_INVALID_HANDLE, const void *completion_key=0, ACE_Proactor *proactor=0) |
int | read (ACE_Message_Block &message_block, size_t bytes_to_read, unsigned long offset=0, unsigned long offset_high=0, const void *act=0, int priority=0, int signal_number=ACE_SIGRTMIN) |
int | readv (ACE_Message_Block &message_block, size_t bytes_to_read, unsigned long offset=0, unsigned long offset_high=0, const void *act=0, int priority=0, int signal_number=ACE_SIGRTMIN) |
virtual ACE_Asynch_Operation_Impl * | implementation (void) const |
Return the underlying implementation class. | |
Protected Attributes | |
ACE_Asynch_Read_File_Impl * | implementation_ |
Private Member Functions | |
void | operator= (const ACE_Asynch_Read_File &) |
ACE_Asynch_Read_File (const ACE_Asynch_Read_File &) |
This class is a factory for starting off asynchronous reads on a file. This class forwards all methods to its implementation class.
Once open() is called, multiple asynchronous reads can started using this class. An ACE_Asynch_Read_File::Result will be passed back to the completion handler's ACE_Handler::handle_read_file() method when each asynchronous read completes. This class differs slightly from ACE_Asynch_Read_Stream as it allows the user to specify an offset for the read.
ACE_Asynch_Read_File::ACE_Asynch_Read_File | ( | void | ) |
A do nothing constructor.
ACE_Asynch_Read_File::~ACE_Asynch_Read_File | ( | void | ) | [virtual] |
Destructor.
ACE_Asynch_Read_File::ACE_Asynch_Read_File | ( | const ACE_Asynch_Read_File & | ) | [private] |
ACE_Asynch_Operation_Impl * ACE_Asynch_Read_File::implementation | ( | void | ) | const [virtual] |
Return the underlying implementation class.
Reimplemented from ACE_Asynch_Read_Stream.
int ACE_Asynch_Read_File::open | ( | ACE_Handler & | handler, |
ACE_HANDLE | handle = ACE_INVALID_HANDLE , |
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const void * | completion_key = 0 , |
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ACE_Proactor * | proactor = 0 |
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Initializes the factory with information which will be used with each asynchronous operation.
handler | ACE_Handler to be notified when operations initiated via this factory complete. The ACE_Handler::handle_read_file() method will be called on this object. |
handle | The file handle to initiate read operations on. If handle is ACE_INVALID_HANDLE , ACE_Handler::handle() will be called on handler to get the handle value. |
completion_key | A token that is passed to the completion handler. |
proactor | The ACE_Proactor object which will control operation completion and dispatching the results to handler. If this is 0, the process's singleton ACE_Proactor will be used. |
0 | for success. |
-1 | for failure; consult errno for further information. |
Reimplemented from ACE_Asynch_Read_Stream.
void ACE_Asynch_Read_File::operator= | ( | const ACE_Asynch_Read_File & | ) | [private] |
int ACE_Asynch_Read_File::read | ( | ACE_Message_Block & | message_block, |
size_t | bytes_to_read, | ||
unsigned long | offset = 0 , |
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unsigned long | offset_high = 0 , |
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const void * | act = 0 , |
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int | priority = 0 , |
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int | signal_number = ACE_SIGRTMIN |
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) |
This starts off an asynchronous read. Upto {bytes_to_read} will be read and stored in the {message_block}. The read will start at {offset} from the beginning of the file. Priority of the operation is specified by {priority}. On POSIX4-Unix, this is supported. Works like {nice} in Unix. Negative values are not allowed. 0 means priority of the operation same as the process priority. 1 means priority of the operation is one less than process. And so forth. On Win32, this argument is a no-op. {signal_number} is the POSIX4 real-time signal number to be used for the operation. {signal_number} ranges from ACE_SIGRTMIN to ACE_SIGRTMAX. This argument is a no-op on non-POSIX4 systems.
int ACE_Asynch_Read_File::readv | ( | ACE_Message_Block & | message_block, |
size_t | bytes_to_read, | ||
unsigned long | offset = 0 , |
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unsigned long | offset_high = 0 , |
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const void * | act = 0 , |
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int | priority = 0 , |
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int | signal_number = ACE_SIGRTMIN |
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Same as above but with scatter support, through chaining of composite message blocks using the continuation field.
Delegation/implementation class that all methods will be forwarded to.
Reimplemented from ACE_Asynch_Read_Stream.