ACEXML_Mem_Map_Stream Class Reference

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

#include <ACEXML/common/Mem_Map_Stream.h>

Collaboration diagram for ACEXML_Mem_Map_Stream:

[legend]List of all members.

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 .
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 method will start.
char *	get_pos_
char *	end_of_mapping_plus1_
	Address at the end of the file mapping.

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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 position, which keeps track of the beginning of a token that is in the stream.

2. The 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 . The length of the token, i.e., the , is the length in bytes between the position and the position. Once the token has been extracted, the and positions can be updated by the method.

Definition at line 55 of file Mem_Map_Stream.h.

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Constructor & Destructor Documentation

ACEXML_Mem_Map_Stream::ACEXML_Mem_Map_Stream (  void   )

Default constructor. Definition at line 9 of file Mem_Map_Stream.cpp. : svc_handler_ (0) { }

ACEXML_Mem_Map_Stream::~ACEXML_Mem_Map_Stream (  void   )  [virtual]

Destructor. Definition at line 258 of file Mem_Map_Stream.cpp. References mem_map_, and ACE_Mem_Map::remove(). { // Remove the mapping and the file. this->mem_map_.remove (); delete this->svc_handler_; }

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Member Function Documentation

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

Returns the no. of bytes available in the stream. Definition at line 137 of file Mem_Map_Stream.cpp. References end_of_mapping_plus1_, and get_pos_. Referenced by ACEXML_HttpCharStream::available(). { return this->end_of_mapping_plus1_ - this->get_pos_; }

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

Returns 1 if we're at the end of the HTTP stream, else 0. Definition at line 29 of file Mem_Map_Stream.cpp. References end_of_mapping_plus1_, and get_pos_. Referenced by get_char(), and recv(). { return this->get_pos_ >= this->end_of_mapping_plus1_; }

int ACEXML_Mem_Map_Stream::get_char (  void   )  [virtual]

Return the next character in the stream and advance the position. Returns EOF when the position reaches the end of the HTTP stream. Definition at line 35 of file Mem_Map_Stream.cpp. References eof(), get_pos_, and grow_file_and_remap(). Referenced by ACEXML_HttpCharStream::determine_encoding(), and ACEXML_HttpCharStream::get(). { if (this->eof () && this->grow_file_and_remap () == -1) return EOF; return *this->get_pos_++; }

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. Definition at line 188 of file Mem_Map_Stream.cpp. References ACE_DEFAULT_TIMEOUT, ACE_ERROR, ACE_ERROR_RETURN, ACE_MAP_PRIVATE, ACE_Mem_Map::addr(), end_of_mapping_plus1_, EWOULDBLOCK, get_pos_, LM_ERROR, ACE_Mem_Map::map(), MAP_FAILED, mem_map_, ACE_Svc_Handler<, >::peer(), PROT_RDWR, recv_pos_, ACE_Mem_Map::size(), ssize_t, and ACE::write_n(). Referenced by get_char(), peek_char(), peek_str(), recv(), and seek(). { char buf[8192]; // Copy the next chunk of bytes from the socket into the temporary // file. ACE_Time_Value tv (ACE_DEFAULT_TIMEOUT); ssize_t bytes = 0; ssize_t n = 0; while (1) { n = this->svc_handler_->peer ().recv (buf, sizeof buf, 0, &tv); if (n < 0) { if (errno != EWOULDBLOCK) { ACE_ERROR ((LM_ERROR, "%p\n", "recv")); } return -1; } bytes += n; if (n == 0 && !bytes) return -1; else if (n == 0) break; else if (ACE::write_n (this->mem_map_.handle (), buf, n) != n) ACE_ERROR_RETURN ((LM_ERROR, "%p\n", "write_n"), -1); } // ssize_t n = this->svc_handler_->peer ().recv (buf, sizeof buf, 0, &tv); // if (n == -1) // { // ACE_ERROR ((LM_ERROR, "%p\n", "recv")); // return -1; // } // else if (n == 0) // return -1; // else if (ACE::write_n (this->mem_map_.handle (), buf, n) != n) // ACE_ERROR_RETURN ((LM_ERROR, // "%p\n", // "write_n"), // -1); // Grow the memory-mapping to encompass the entire temporary file. if (this->mem_map_.map (static_cast<size_t> (-1), PROT_RDWR, ACE_MAP_PRIVATE, (void*)0) == -1) ACE_ERROR_RETURN ((LM_ERROR, "%p\n", "map"), -1); // MAP_FAILED is used as a "first time in" flag. if (this->recv_pos_ == MAP_FAILED) { this->recv_pos_ = reinterpret_cast<char *> (this->mem_map_.addr ()); this->get_pos_ = this->recv_pos_; } this->end_of_mapping_plus1_ = reinterpret_cast<char *> (this->mem_map_.addr ()) + this->mem_map_.size (); return 0; }

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

Initialize this object. Definition at line 143 of file Mem_Map_Stream.cpp. References ACE_DEFAULT_FILE_PERMS, ACE_ERROR_RETURN, ACE_Connector< SVC_HANDLER, >::connect(), Connector, ACE_INET_Addr::get_host_name(), ACE_FILE_Addr::get_path_name(), ACE_INET_Addr::get_port_number(), LM_ERROR, mem_map_, ACE_Mem_Map::open(), rewind(), and ACE_OS::unlink(). Referenced by ACEXML_HttpCharStream::open(). { svc_handler_ = 0; // Connect to the server at <addr>. If the handler has to be // connected to the server again, the Caching strategy takes care // and uses the same connection. if (connector->connect (svc_handler_, addr) == -1) { ACE_ERROR_RETURN ((LM_ERROR, "%p %s %d\n", "Connect failed", addr.get_host_name (), addr.get_port_number ()), -1); } // Create a temporary filename. ACE_FILE_Addr file (ACE_sap_any_cast (ACE_FILE_Addr &)); // Create the temporary file via the <ACE_Mem_Map> class API. if (this->mem_map_.open (file.get_path_name (), O_RDWR | O_CREAT | O_APPEND, ACE_DEFAULT_FILE_PERMS) == -1) ACE_ERROR_RETURN ((LM_ERROR, "%p\n", "open"), -1); // Make sure to unlink this right away so that if this process // crashes these files will be removed automatically. else if (ACE_OS::unlink (file.get_path_name ()) == -1) ACE_ERROR_RETURN ((LM_ERROR, "%p\n", "unlink"), -1); else // Initialize all the position pointers to 0. this->rewind (); return 0; }

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

Returns the nth character from the position in the stream without advancing the position. Automatically extends the backing store if necessary. Returns EOF if is past the end of the stream. Definition at line 51 of file Mem_Map_Stream.cpp. References end_of_mapping_plus1_, get_pos_, and grow_file_and_remap(). Referenced by ACEXML_HttpCharStream::determine_encoding(), and ACEXML_HttpCharStream::peek(). { // We may need to iterate if the size of <n> is large. while (this->get_pos_ + offset >= this->end_of_mapping_plus1_) if (this->grow_file_and_remap () == -1) return EOF; return this->get_pos_[offset]; }

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

Return a pointer to an array of characters starting at characters from the position in the stream without advancing the position. Automatically extends the backing store if necessary. Returns 0 if or <offset + size> is past the end of the stream. Definition at line 88 of file Mem_Map_Stream.cpp. References end_of_mapping_plus1_, get_pos_, and grow_file_and_remap(). { // We will iterate if the size of <offset> is large. while (this->get_pos_ + (offset + size) > this->end_of_mapping_plus1_) if (this->grow_file_and_remap () == -1) return 0; return &this->get_pos_[offset]; }

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

Returns a pointer to array of characters starting at the position. Definition at line 62 of file Mem_Map_Stream.cpp. References recv_pos_. { return this->recv_pos_; }

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

Returns a pointer to array of at most characters starting at the position. If the position + extends past the EOF then is set to the number of characters between the position and the EOF and both the and positions are advanced by . Returns 0 if the position is at the EOF. Definition at line 68 of file Mem_Map_Stream.cpp. References eof(), get_pos_, grow_file_and_remap(), recv_pos_, and seek(). Referenced by ACEXML_HttpCharStream::get_url(), and ACEXML_HttpCharStream::read(). { if (this->eof () && this->grow_file_and_remap () == -1) { len = 0; return 0; } const char *s = this->recv_pos_; this->seek (static_cast<ACE_OFF_T> (len), SEEK_CUR); len = this->get_pos_ - s; return s; }

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

Returns the length in bytes between the position and the position. Definition at line 82 of file Mem_Map_Stream.cpp. References get_pos_, and recv_pos_. { return this->get_pos_ - this->recv_pos_; }

void ACEXML_Mem_Map_Stream::rewind (  void   )  [virtual]

Resets the and positions to the beginning of the stream. This works since all the data has been cached in the memory-mapped backing store. Definition at line 43 of file Mem_Map_Stream.cpp. References ACE_Mem_Map::addr(), end_of_mapping_plus1_, get_pos_, mem_map_, recv_pos_, and ACE_Mem_Map::size(). Referenced by ACEXML_HttpCharStream::get_url(), open(), and ACEXML_HttpCharStream::rewind(). { this->recv_pos_ = reinterpret_cast<char *> (this->mem_map_.addr ()); this->get_pos_ = this->recv_pos_; this->end_of_mapping_plus1_ = this->recv_pos_ + this->mem_map_.size (); }

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

Sets the and positions as follows: o If is , the positions are set to bytes from the start of the stream. o If is , the positions are set to the current position plus . o If is , the positions are set to the size of the stream plus . If offset is greater than EOF, both and are set to EOF. Note special return value is returned to indicate this condition. Definition at line 100 of file Mem_Map_Stream.cpp. References ACE_NOTSUP_RETURN, ACE_Mem_Map::addr(), end_of_mapping_plus1_, get_pos_, grow_file_and_remap(), mem_map_, and recv_pos_. Referenced by ACEXML_HttpCharStream::get_url(), recv(), and ACEXML_HttpCharStream::rewind(). { switch (whence) { case SEEK_SET: this->get_pos_ = reinterpret_cast<char *> (this->mem_map_.addr ()) + offset; break; case SEEK_CUR: this->get_pos_ += offset; break; case SEEK_END: this->get_pos_ = this->end_of_mapping_plus1_ + offset; // @@ Not sure how to implement this (yet). ACE_NOTSUP_RETURN (-1); } // Make sure that the backing store will cover this. while (this->get_pos_ > this->end_of_mapping_plus1_) if (this->grow_file_and_remap () == -1) this->get_pos_ = this->end_of_mapping_plus1_; this->recv_pos_ = this->get_pos_; return this->recv_pos_ - reinterpret_cast<char *> (this->mem_map_.addr ()); }

ssize_t ACEXML_Mem_Map_Stream::send_n (  const void *  buf, size_t  size, ACE_Time_Value *  tv = 0 )  [virtual]

Send bytes in to the connected peer. This is a completely unbuffered call. Definition at line 22 of file Mem_Map_Stream.cpp. References ACE_Svc_Handler<, >::peer(). Referenced by ACEXML_HttpCharStream::send_request(). { return svc_handler_->peer ().send_n (buf, size, 0, tv); }

ACE_SOCK_Stream & ACEXML_Mem_Map_Stream::stream (  void   )

Returns the underlying . Definition at line 16 of file Mem_Map_Stream.cpp. References ACE_Svc_Handler<, >::peer(). { return svc_handler_->peer (); }

Svc_Handler * ACEXML_Mem_Map_Stream::svc_handler (  void   )

Returns the underlying service handler. Definition at line 131 of file Mem_Map_Stream.cpp. { return this->svc_handler_; }

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Member Data Documentation

char* ACEXML_Mem_Map_Stream::end_of_mapping_plus1_ [private]

Address at the end of the file mapping. Definition at line 183 of file Mem_Map_Stream.h. Referenced by available(), eof(), grow_file_and_remap(), peek_char(), peek_str(), rewind(), and seek().

char* ACEXML_Mem_Map_Stream::get_pos_ [private]

Pointer to the address where the next method will start. Definition at line 180 of file Mem_Map_Stream.h. Referenced by available(), eof(), get_char(), grow_file_and_remap(), peek_char(), peek_str(), recv(), recv_len(), rewind(), and seek().

ACE_Mem_Map ACEXML_Mem_Map_Stream::mem_map_ [private]

Memory-mapped file that we're iterating over. Definition at line 171 of file Mem_Map_Stream.h. Referenced by grow_file_and_remap(), open(), rewind(), seek(), and ~ACEXML_Mem_Map_Stream().

char* ACEXML_Mem_Map_Stream::recv_pos_ [private]

Pointer to the address where the next method will start. Definition at line 174 of file Mem_Map_Stream.h. Referenced by grow_file_and_remap(), recv(), recv_len(), rewind(), and seek().

Svc_Handler* ACEXML_Mem_Map_Stream::svc_handler_ [private]

Connection to peer. The granularity is at the Svc_Handler level. The Svc_Handler has an SOCK_Stream. Definition at line 168 of file Mem_Map_Stream.h.

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

• Mem_Map_Stream.h
• Mem_Map_Stream.cpp

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