Provides a memory-mapped stream abstraction to simplify parsing of tokens. More...

#include <Mem_Map_Stream.h>

Collaboration diagram for ACEXML_Mem_Map_Stream:

Public Member Functions
	ACEXML_Mem_Map_Stream (void)
	Default constructor.
virtual int	open (Connector *connector, const ACE_INET_Addr &)
	Initialize this object.
virtual	~ACEXML_Mem_Map_Stream (void)
	Destructor.
ACE_SOCK_Stream &	stream (void)
	Returns the underlying <ACE_SOCK_Stream>.
virtual ssize_t	send_n (const void buf, size_t size, ACE_Time_Value tv=0)
virtual int	get_char (void)
virtual const char *	recv (size_t &len)
virtual const char *	recv (void) const
virtual size_t	recv_len (void) const
virtual size_t	available (void) const
virtual void	rewind (void)
virtual int	peek_char (size_t offset)
virtual const char *	peek_str (size_t offset, size_t size)
virtual ACE_OFF_T	seek (ACE_OFF_T offset, int whence=SEEK_CUR)
virtual int	eof (void) const
	Returns 1 if we're at the end of the HTTP stream, else 0.
Svc_Handler *	svc_handler (void)
	Returns the underlying service handler.
Private Member Functions
int	grow_file_and_remap (void)
Private Attributes
Svc_Handler *	svc_handler_
ACE_Mem_Map	mem_map_
	Memory-mapped file that we're iterating over.
char *	recv_pos_
	Pointer to the address where the next <recv> method will start.
char *	get_pos_
char *	end_of_mapping_plus1_
	Address at the end of the file mapping.

Detailed Description

Provides a memory-mapped stream abstraction to simplify parsing of tokens.

This class makes it possible to treat an connection as a stream of bytes, similar to the C library stdio streams. The contents of the connection are buffered incrementally in a memory-mapped file. This class maintains pointers to two positions in the stream:

1. The <recv> position, which keeps track of the beginning of a token that is in the stream.

2. The <get> position, which moves along character-by-character until the end of the token is reached.

Once a token has been located, it can be extracted from the stream by calling the <recv>. The length of the token, i.e., the <recv_len>, is the length in bytes between the <get> position and the <recv> position. Once the token has been extracted, the <recv> and <get> positions can be updated by the <seek> method.

Constructor & Destructor Documentation

ACEXML_Mem_Map_Stream::ACEXML_Mem_Map_Stream ( void )

Default constructor.

ACEXML_Mem_Map_Stream::~ACEXML_Mem_Map_Stream ( void ) [virtual]

Destructor.

Member Function Documentation

size_t ACEXML_Mem_Map_Stream::available ( void ) const [virtual]

Returns the no. of bytes available in the stream.

int ACEXML_Mem_Map_Stream::eof ( void ) const [virtual]

Returns 1 if we're at the end of the HTTP stream, else 0.

int ACEXML_Mem_Map_Stream::get_char ( void ) [virtual]

Return the next character in the stream and advance the <get> position. Returns EOF when the <get> position reaches the end of the HTTP stream.

int ACEXML_Mem_Map_Stream::grow_file_and_remap ( void ) [private]

Grow the file by reading another chunk from the HTTP socket and extend the mapping to cover this chunk. Returns -1 on failure or EOF, else 0.

int ACEXML_Mem_Map_Stream::open	(	Connector *	connector,
		const ACE_INET_Addr &	addr
	)		`[virtual]`

Initialize this object.

int ACEXML_Mem_Map_Stream::peek_char ( size_t offset ) [virtual]

Returns the nth character <offset> from the <get> position in the stream without advancing the <get> position. Automatically extends the backing store if necessary. Returns EOF if <offset> is past the end of the stream.

const char * ACEXML_Mem_Map_Stream::peek_str	(	size_t	offset,
		size_t	size
	)		`[virtual]`

Return a pointer to an array of <size> characters starting at <offset> characters from the <get> position in the stream without advancing the <get> position. Automatically extends the backing store if necessary. Returns 0 if <offset> or <offset + size> is past the end of the stream.

const char * ACEXML_Mem_Map_Stream::recv ( size_t & len ) [virtual]

Returns a pointer to array of at most <len> characters starting at the <recv> position. If the <recv> position + <len> extends past the EOF then <len> is set to the number of characters between the <recv> position and the EOF and both the <get> and <recv> positions are advanced by <len>. Returns 0 if the <recv> position is at the EOF.

const char * ACEXML_Mem_Map_Stream::recv ( void ) const [virtual]

Returns a pointer to array of characters starting at the <recv> position.

size_t ACEXML_Mem_Map_Stream::recv_len ( void ) const [virtual]

Returns the length in bytes between the <get> position and the <recv> position.

void ACEXML_Mem_Map_Stream::rewind ( void ) [virtual]

Resets the <get> and <recv> positions to the beginning of the stream. This works since all the data has been cached in the memory-mapped backing store.

ACE_OFF_T ACEXML_Mem_Map_Stream::seek	(	ACE_OFF_T	offset,
		int	whence = `SEEK_CUR`
	)		`[virtual]`

Sets the <get> and <recv> positions as follows: o If <whence> is <SEEK_SET>, the positions are set to <offset> bytes from the start of the stream. o If <whence> is <SEEK_CUR>, the positions are set to the current <get> position plus <offset>. o If <whence> is <SEEK_END>, the positions are set to the size of the stream plus <offset>.

If offset is greater than EOF, both <get> and <recv> are set to EOF. Note special return value is returned to indicate this condition.