WvGzipStream Class Reference

#include <wvgzipstream.h>

Inheritance diagram for WvGzipStream:
[legend]

List of all members.


Detailed Description

A stream implementing Gzip compression and decompression.

By default, written data is compressed using WvGzipEncoder::Deflate, read data is decompressed using WvGzipEncoder::Inflate.

See also:
WvGzipEncoder

Definition at line 20 of file wvgzipstream.h.


Public Member Functions

 WvGzipStream (WvStream *_cloned, WvGzipEncoder::Mode readmode=WvGzipEncoder::Inflate, WvGzipEncoder::Mode writemode=WvGzipEncoder::Deflate)
const char * wstype () const
virtual void close ()
 Safely shuts down the stream.
bool flush_read ()
 Flushes the read chain through to the stream's input buffer.
bool flush_write ()
 Flushes the write chain through to the stream's output buffer.
bool finish_read ()
 Calls flush() then finish() on the read chain of encoders.
bool finish_write ()
 Calls flush() then finish() on the write chain of encoders.
virtual bool isok () const
 Defines isok() semantics for encoders.
virtual size_t uread (void *buf, size_t size)
 unbuffered I/O functions; these ignore the buffer, which is handled by read().
virtual size_t uwrite (const void *buf, size_t size)
 unbuffered I/O functions; these ignore the buffer, which is handled by write().
void pre_select (SelectInfo &si, const SelectRequest &r)
 A more convenient version of pre_select() usable for overriding the 'want' value temporarily.
bool post_select (SelectInfo &si, const SelectRequest &r)
 A more convenient version of post_select() usable for overriding the 'want' value temporarily.
virtual void setclone (IWvStream *clone)
virtual int geterr () const
virtual WvString errstr () const
virtual const WvAddrsrc () const
 get the remote address from which the last data block was received.
virtual void execute ()
 The callback() function calls execute(), and then calls the user- specified callback if one is defined.
virtual void noread ()
virtual void nowrite ()
virtual void seterr (int _errnum)
 Override seterr() from WvError so that it auto-closes the stream.
void seterr (WvStringParm specialerr)
void seterr (WVSTRING_FORMAT_DECL)
virtual size_t read (void *buf, size_t count)
 read a data block on the stream.
virtual size_t read (WvBuf &outbuf, size_t count)
 Reads up to 'count' bytes of data from the stream into the buffer.
virtual void unread (WvBuf &outbuf, size_t count)
 Puts data back into the stream's internal buffer.
virtual size_t write (const void *buf, size_t count)
 Write data to the stream.
virtual size_t write (WvBuf &inbuf, size_t count=INT_MAX)
 Writes data to the stream from the given buffer.
size_t write (WvStringParm s)
 print a preformatted WvString to the stream.
void outbuf_limit (size_t size)
 set the maximum size of outbuf, beyond which a call to write() will return 0.
virtual void maybe_autoclose ()
virtual bool isreadable ()
virtual bool iswritable ()
char * getline (time_t wait_msec=0, char separator= '\n', int readahead=1024)
 Read up to one line of data from the stream and return a pointer to the internal buffer containing this line.
char * getline (int wait_msec, char separator= '\n', int readahead=1024)
 Auto-convert int to time_t.
char * getline (double wait_msec, char separator= '\n', int readahead=1024)
 Auto-convert double to time_t.
char * blocking_getline (time_t wait_msec, int separator= '\n', int readahead=1024)
 This is a version of getline() that allows you to block for more data to arrive.
char * continue_getline (time_t wait_msec, int separator= '\n', int readahead=1024)
 This is a version of blocking_getline() that uses continue_select to avoid blocking other streams.
void queuemin (size_t count)
 force read() to not return any bytes unless 'count' bytes can be read at once.
void drain ()
 drain the input buffer (read and discard data until select(0) returns false)
void delay_output (bool is_delayed)
 force write() to always buffer output.
void auto_flush (bool is_automatic)
 if true, force write() to call flush() each time, the default behavour.
virtual bool flush (time_t msec_timeout)
 flush the output buffer, if we can do it without delaying more than msec_timeout milliseconds at a time.
virtual bool should_flush ()
void flush_then_close (int msec_timeout)
 flush the output buffer automatically as select() is called.
void xpre_select (SelectInfo &si, const SelectRequest &r)
 Like pre_select(), but still exists even if you override the other pre_select() in a subclass.
bool xpost_select (SelectInfo &si, const SelectRequest &r)
 Like post_select(), but still exists even if you override the other post_select() in a subclass.
bool select (time_t msec_timeout)
 Return true if any of the requested features are true on the stream.
bool select (time_t msec_timeout, bool readable, bool writable, bool isex=false)
 This version of select() sets forceable==false, so we use the exact readable/writable/isexception options provided.
void runonce (time_t msec_timeout=-1)
 Exactly the same as: if (select(timeout)) callback();.
IWvStream::SelectRequest get_select_request ()
 Use get_select_request() to save the current state of the selection state of this stream.
void force_select (bool readable, bool writable, bool isexception=false)
 Use force_select() to force one or more particular modes (readable, writable, or isexception) to true when selecting on this stream.
void undo_force_select (bool readable, bool writable, bool isexception=false)
 Undo a previous force_select() - ie.
bool continue_select (time_t msec_timeout)
 return to the caller from execute(), but don't really return exactly; this uses WvCont::yield() to return to the caller of callback() without losing our place in execute() itself.
void terminate_continue_select ()
 you MUST run this from your destructor if you use continue_select(), or very weird things will happen if someone deletes your object while in continue_select().
void setcallback (WvStreamCallback _callfunc, void *_userdata)
 define the callback function for this stream, called whenever the callback() member is run, and passed the 'userdata' pointer.
IWvStreamCallback setreadcallback (IWvStreamCallback _callback)
 Sets a callback to be invoked when the stream is readable.
IWvStreamCallback setwritecallback (IWvStreamCallback _callback)
 Sets a callback to be invoked when the stream is writable.
IWvStreamCallback setexceptcallback (IWvStreamCallback _callback)
 Sets a callback to be invoked when the stream is in exception state.
IWvStreamCallback setclosecallback (IWvStreamCallback _callback)
 Sets a callback to be invoked on close().
void autoforward (WvStream &s)
 set the callback function for this stream to an internal routine that auto-forwards all incoming stream data to the given output stream.
void noautoforward ()
 Stops autoforwarding.
void * _callwrap (void *)
 A wrapper that's compatible with WvCont, but calls the "real" callback.
void _callback ()
 Actually call the registered callfunc and execute().
virtual void callback ()
 if the stream has a callback function defined, call it now.
void alarm (time_t msec_timeout)
 set an alarm, ie.
time_t alarm_remaining ()
 return the number of milliseconds remaining before the alarm will go off; -1 means no alarm is set (infinity), 0 means the alarm has been hit and will be cleared by the next callback().
size_t print (WvStringParm s)
size_t print (WVSTRING_FORMAT_DECL)
 preformat and write() a string.
size_t operator() (WvStringParm s)
size_t operator() (WVSTRING_FORMAT_DECL)
const char * wsname () const
void set_wsname (WvStringParm wsname)
void set_wsname (WVSTRING_FORMAT_DECL)
WSID wsid () const

Static Public Member Functions

static void autoforward_callback (WvStream &s, void *userdata)
static IWvStream * find_by_wsid (WSID wsid)

Public Attributes

WvEncoderChain readchain
 Encoder chain through which input data is passed.
WvEncoderChain writechain
 Encoder chain through which output data is passed.
size_t min_readsize
 Controls the minimum number of unencoded bytes the encoder should try to read at once from the underlying stream, to optimize performance of block-oriented protocols.
IWvStream * cloned
bool disassociate_on_close
WvStreamread_requires_writable
 If this is set, select() doesn't return true for read unless the given stream also returns true for write.
WvStreamwrite_requires_readable
 If this is set, select() doesn't return true for write unless the given stream also returns true for read.
bool uses_continue_select
 If this is set, enables the use of continue_select().
size_t personal_stack_size
 Specifies the stack size to reserve for continue_select().
bool alarm_was_ticking
 This will be true during callback execution if the callback was triggered by the alarm going off.
bool stop_read
 True if noread()/nowrite()/close() have been called, respectively.
bool stop_write
bool closed

Protected Member Functions

void pre_select (SelectInfo &si)
 pre_select() sets up for eventually calling select().
bool post_select (SelectInfo &si)
 post_select() is called after select(), and returns true if this object is now ready.
virtual bool flush_internal (time_t msec_timeout)
void _build_selectinfo (SelectInfo &si, time_t msec_timeout, bool readable, bool writable, bool isexcept, bool forceable)
int _do_select (SelectInfo &si)
bool _process_selectinfo (SelectInfo &si, bool forceable)
bool flush_outbuf (time_t msec_timeout)
virtual int getrfd () const
virtual int getwfd () const

Static Protected Member Functions

static void debugger_streams_display_header (WvStringParm cmd, WvStreamsDebugger::ResultCallback result_cb)
static void debugger_streams_display_one_stream (WvStream *s, WvStringParm cmd, WvStreamsDebugger::ResultCallback result_cb)
static void debugger_streams_maybe_display_one_stream (WvStream *s, WvStringParm cmd, const WvStringList &args, WvStreamsDebugger::ResultCallback result_cb)

Protected Attributes

WvString my_type
WvDynBuf inbuf
WvDynBuf outbuf
WvStreamCallback callfunc
void * userdata
WvCallback< void *, void * > call_ctx
IWvStreamCallback readcb
IWvStreamCallback writecb
IWvStreamCallback exceptcb
IWvStreamCallback closecb
size_t max_outbuf_size
bool outbuf_delayed_flush
bool is_auto_flush
bool want_to_flush
bool is_flushing
size_t queue_min
time_t autoclose_time
WvTime alarm_time
WvTime last_alarm_check

Static Protected Attributes

static WvStreamglobalstream = NULL

Friends

class WvHTTPClientProxyStream

Member Function Documentation

void WvEncoderStream::close (  )  [virtual, inherited]

Safely shuts down the stream.

Does the following in sequence:

Reimplemented from WvStreamClone.

Definition at line 24 of file wvencoderstream.cc.

References WvStreamClone::close(), WvEncoderStream::finish_read(), and WvEncoderStream::finish_write().

bool WvEncoderStream::flush_read (  )  [inherited]

Flushes the read chain through to the stream's input buffer.

The regular stream flush() only operates on the write chain.

Returns: true if the encoder chain returned true

Definition at line 70 of file wvencoderstream.cc.

References WvEncoder::flush(), WvBufBaseCommonImpl< T >::merge(), and WvEncoderStream::readchain.

bool WvEncoderStream::flush_write (  )  [inherited]

Flushes the write chain through to the stream's output buffer.

The regular stream flush() invokes this, then attempts to synchronously push the buffered data to the stream, which may not always be desirable since it can be quite costly.

To simply cause the write chain to be flushed but allow WvStreams to drain the encoded output buffer at its leisure, use this function.

Returns: true if the encoder chain returned true

Definition at line 79 of file wvencoderstream.cc.

bool WvEncoderStream::finish_read (  )  [inherited]

Calls flush() then finish() on the read chain of encoders.

Returns: true if the encoder chain returned true

Definition at line 86 of file wvencoderstream.cc.

References WvEncoder::finish(), WvEncoder::flush(), WvBufBaseCommonImpl< T >::merge(), and WvEncoderStream::readchain.

Referenced by WvEncoderStream::close().

bool WvEncoderStream::finish_write (  )  [inherited]

Calls flush() then finish() on the write chain of encoders.

Does not flush() the stream.

Returns: true if the encoder chain returned true.

Definition at line 98 of file wvencoderstream.cc.

Referenced by WvEncoderStream::close().

bool WvEncoderStream::isok (  )  const [virtual, inherited]

Defines isok() semantics for encoders.

Returns false on error or after all data has been read from the internal buffers and readchain.isfinished() or ! writechain.isok().

Returns: true if it is still possible to read and write data

Reimplemented from WvStreamClone.

Definition at line 44 of file wvencoderstream.cc.

References WvStream::isok().

size_t WvEncoderStream::uread ( void *  buf,
size_t  count 
) [virtual, inherited]

unbuffered I/O functions; these ignore the buffer, which is handled by read().

Don't call these functions explicitly unless you have a _really_ good reason.

This is what you would override in a derived class.

Reimplemented from WvStreamClone.

Definition at line 178 of file wvencoderstream.cc.

References WvEncoderStream::min_readsize, WvBufBaseCommonImpl< T >::move(), and WvBufBaseCommonImpl< T >::used().

size_t WvEncoderStream::uwrite ( const void *  buf,
size_t  count 
) [virtual, inherited]

unbuffered I/O functions; these ignore the buffer, which is handled by write().

Don't call these functions explicitly unless you have a _really_ good reason.

This is what you would override in a derived class.

Reimplemented from WvStreamClone.

Definition at line 191 of file wvencoderstream.cc.

References WvBufBaseCommonImpl< T >::put().

void WvEncoderStream::pre_select ( SelectInfo &  si  )  [protected, virtual, inherited]

pre_select() sets up for eventually calling select().

It adds the right fds to the read, write, and except lists in the SelectInfo struct.

Returns true if we already know this stream is ready, and there's no need to actually do a real select(). Some streams, such as timers, can be implemented by _only_ either returning true or false here after doing a calculation, and never actually adding anything to the SelectInfo.

You can add your stream to any of the lists even if readable, writable, or isexception isn't set. This is what force_select() does. You can also choose not to add yourself to the list if you know it would be useless right now.

pre_select() is only called if isok() is true.

pre_select() is allowed to reduce msec_timeout (or change it if it's -1). However, it's not allowed to _increase_ msec_timeout.

Reimplemented from WvStreamClone.

Definition at line 199 of file wvencoderstream.cc.

References WvStreamClone::pre_select(), and WvBufBaseCommonImpl< T >::used().

bool WvEncoderStream::post_select ( SelectInfo &  si  )  [protected, virtual, inherited]

post_select() is called after select(), and returns true if this object is now ready.

Usually this is done by checking for this object in the read, write, and except lists in the SelectInfo structure. If you want to do it in some other way, you should usually do it in pre_select() instead.

You may also want to do extra maintenance functions here; for example, the standard WvStream::post_select tries to flush outbuf if it's nonempty. WvTCPConn might retry connect() if it's waiting for a connection to be established.

Reimplemented from WvStreamClone.

Definition at line 208 of file wvencoderstream.cc.

References WvStreamClone::post_select(), and WvBufBaseCommonImpl< T >::used().

const WvAddr * WvStreamClone::src (  )  const [virtual, inherited]

get the remote address from which the last data block was received.

May be NULL. The pointer becomes invalid upon the next call to read().

Reimplemented from WvStream.

Definition at line 254 of file wvstreamclone.cc.

void WvStreamClone::execute (  )  [virtual, inherited]

The callback() function calls execute(), and then calls the user- specified callback if one is defined.

Do not call execute() directly; call callback() instead.

The default execute() function does nothing.

Note: If you override this function in a derived class, you must call the parent execute() yourself from the derived class.

Reimplemented from WvStream.

Reimplemented in UniConfDaemonConn, and WvProtoStream.

Definition at line 262 of file wvstreamclone.cc.

References WvStream::execute().

Referenced by WvProtoStream::execute(), and UniConfDaemonConn::execute().

void WvStream::seterr ( int  _errnum  )  [virtual, inherited]

Override seterr() from WvError so that it auto-closes the stream.

Definition at line 415 of file wvstream.cc.

References WvStream::close(), and WvErrorBase::seterr().

Referenced by WvTCPConn::check_resolver(), WvTCPConn::do_connect(), WvTCPConn::post_select(), WvSSLStream::post_select(), UniIniGen::refresh(), WvSSLStream::uread(), WvFdStream::uread(), WvUDPStream::uwrite(), WvSSLStream::uwrite(), WvIPRawStream::uwrite(), WvFdStream::uwrite(), WvDsp::WvDsp(), WvIPRawStream::WvIPRawStream(), WvSSLStream::WvSSLStream(), WvTCPListener::WvTCPListener(), WvUDPStream::WvUDPStream(), and WvUnixConn::WvUnixConn().

size_t WvStream::read ( void *  buf,
size_t  count 
) [virtual, inherited]

read a data block on the stream.

Returns the actual amount read.

Definition at line 454 of file wvstream.cc.

References WvBufBaseCommonImpl< T >::alloc(), WvBufBaseCommonImpl< T >::get(), WvBufBaseCommonImpl< T >::unalloc(), WvStream::uread(), and WvBufBaseCommonImpl< T >::used().

Referenced by WvStream::drain(), UniFileSystemGen::get(), WvStream::read(), and WvFdStream::uread().

size_t WvStream::read ( WvBuf outbuf,
size_t  count 
) [virtual, inherited]

Reads up to 'count' bytes of data from the stream into the buffer.

Returns the actual amount read.

If 'count' is greater than the amount of free space available in the buffer, only reads at most that amount. You should specify a reasonable upper bound on how much data should be read at once.

Definition at line 425 of file wvstream.cc.

References WvBufBaseCommonImpl< T >::alloc(), WvBufBaseCommonImpl< T >::free(), WvBufBaseCommonImpl< T >::merge(), WvStream::read(), and WvBufBaseCommonImpl< T >::unalloc().

void WvStream::unread ( WvBuf outbuf,
size_t  count 
) [virtual, inherited]

Puts data back into the stream's internal buffer.

We cheat so that there's no restriction on how much (or what) data can be unread(). This is different from WvBuf::unget() (which is rather restrictive).

Definition at line 1159 of file wvstream.cc.

References WvBufBaseCommonImpl< T >::merge(), and WvBufBaseCommonImpl< T >::zap().

size_t WvStream::write ( const void *  buf,
size_t  count 
) [virtual, inherited]

Write data to the stream.

Returns the actual amount written. Since WvStream has an output buffer, it *always* successfully "writes" the full amount (but you might have to flush the buffers later so it actually gets sent).

Definition at line 496 of file wvstream.cc.

References WvStream::flush(), WvStream::isok(), WvBufBaseCommonImpl< T >::put(), WvBufBaseCommonImpl< T >::used(), and WvStream::uwrite().

Referenced by WvLogFileBase::_mid_line(), WvModem::close(), WvIStreamList::execute(), WvModemBase::hangup(), WvLog::operator()(), WvStream::print(), UniFileSystemGen::set(), WvProtoStream::uwrite(), WvFdStream::uwrite(), WvDsp::uwrite(), WvStream::write(), and UniClientConn::writecmd().

size_t WvStream::write ( WvBuf inbuf,
size_t  count = INT_MAX 
) [virtual, inherited]

Writes data to the stream from the given buffer.

Returns the actual amount written.

If count is greater than the amount of data available in the buffer, only writes at most that amount.

Definition at line 441 of file wvstream.cc.

References WvBufBaseCommonImpl< T >::get(), WvBufBaseCommonImpl< T >::unget(), WvBufBaseCommonImpl< T >::used(), and WvStream::write().

size_t WvStream::write ( WvStringParm  s  )  [inline, inherited]

print a preformatted WvString to the stream.

see the simple version of write() way up above.

Definition at line 538 of file wvstream.h.

References WvFastString::cstr(), WvFastString::len(), and WvStream::write().

void WvStream::outbuf_limit ( size_t  size  )  [inline, inherited]

set the maximum size of outbuf, beyond which a call to write() will return 0.

I need to do this for tape backups, since all I can do is write to the loopback as fast as I can, which causes us to run out of memory and get SIGABRT'd. (dcoombs: 12/15/2000)

FIXME: there must be a better way. This confuses the semantics of write(); can you trust it to always write all the bytes, or not?

Definition at line 129 of file wvstream.h.

char* WvStream::getline ( time_t  wait_msec = 0,
char  separator = '\n',
int  readahead = 1024 
) [inline, inherited]

Read up to one line of data from the stream and return a pointer to the internal buffer containing this line.

If the end-of-line 'separator' is encountered, it is removed from the string. If there is not a full line available, returns NULL. You can read what we have so far by calling read().

Readahead specifies the maximum amount of data that the stream is allowed to read in one shot.

It is expected that there will be no NULL characters on the line.

wait_msec is provided so that legacy code does not break. But it really should be 0.

Definition at line 175 of file wvstream.h.

References WvStream::blocking_getline().

Referenced by WvProtoStream::execute(), WvIPRouteList::get_kernel(), and WvStream::getline().

char* WvStream::getline ( int  wait_msec,
char  separator = '\n',
int  readahead = 1024 
) [inline, inherited]

Auto-convert int to time_t.

Definition at line 182 of file wvstream.h.

References WvStream::getline().

char* WvStream::getline ( double  wait_msec,
char  separator = '\n',
int  readahead = 1024 
) [inline, inherited]

Auto-convert double to time_t.

Definition at line 189 of file wvstream.h.

References WvStream::getline().

char * WvStream::blocking_getline ( time_t  wait_msec,
int  separator = '\n',
int  readahead = 1024 
) [inherited]

This is a version of getline() that allows you to block for more data to arrive.

This should be used carefully, as blocking is generally unexpected in WvStreams programs.

If wait_msec < 0, it will wait forever for the 'separator' (often a bad idea!). If wait_msed == 0, this is the equivalent of getline().

Definition at line 566 of file wvstream.cc.

References WvBufBaseCommonImpl< T >::alloc(), WvStream::continue_select(), WvBufBaseCommonImpl< T >::get(), WvStream::isok(), WvBufBaseCommonImpl< T >::mutablepeek(), WvBufBaseCommonImpl< T >::put(), WvStream::queuemin(), WvStream::select(), WvStream::stop_read, WvBufBaseCommonImpl< T >::unalloc(), WvStream::uread(), WvBufBaseCommonImpl< T >::used(), and WvStream::uses_continue_select.

Referenced by WvIPRouteList::get_kernel(), WvStream::getline(), and UniIniGen::refresh().

void WvStream::queuemin ( size_t  count  )  [inline, inherited]

force read() to not return any bytes unless 'count' bytes can be read at once.

(Useful for processing Content-Length headers, etc.) Use count==0 to disable this feature.

WARNING: getline() sets queuemin to 0 automatically!

Definition at line 232 of file wvstream.h.

Referenced by WvStream::blocking_getline().

void WvStream::delay_output ( bool  is_delayed  )  [inline, inherited]

force write() to always buffer output.

This can be more efficient if you write a lot of small segments and want to "coagulate" them automatically. To flush the output buffer, use flush() or select().

Definition at line 246 of file wvstream.h.

void WvStream::auto_flush ( bool  is_automatic  )  [inline, inherited]

if true, force write() to call flush() each time, the default behavour.

otherwise, flush() is granted special meaning when explicitly invoked by the client and write() may empty the output buffer, but will not explicitly flush().

Definition at line 258 of file wvstream.h.

bool WvStream::flush ( time_t  msec_timeout  )  [virtual, inherited]

flush the output buffer, if we can do it without delaying more than msec_timeout milliseconds at a time.

(-1 means wait forever)

Returns true if the flushing finished (the output buffer is empty).

Definition at line 671 of file wvstream.cc.

Referenced by WvLogFileBase::_end_line(), WvStream::close(), WvStream::flush_then_close(), WvStreamClone::post_select(), WvStream::post_select(), and WvStream::write().

void WvStream::flush_then_close ( int  msec_timeout  )  [inherited]

flush the output buffer automatically as select() is called.

If the buffer empties, close the stream. If msec_timeout seconds pass, close the stream. After the stream closes, it will become !isok() (and a WvStreamList can delete it automatically)

Definition at line 791 of file wvstream.cc.

References WvStream::flush(), and WvBufBaseCommonImpl< T >::used().

void WvStream::xpre_select ( SelectInfo &  si,
const SelectRequest &  r 
) [inline, inherited]

Like pre_select(), but still exists even if you override the other pre_select() in a subclass.

Sigh.

Definition at line 318 of file wvstream.h.

References WvStream::pre_select().

bool WvStream::xpost_select ( SelectInfo &  si,
const SelectRequest &  r 
) [inline, inherited]

Like post_select(), but still exists even if you override the other post_select() in a subclass.

Sigh.

Definition at line 339 of file wvstream.h.

References WvStream::post_select().

bool WvStream::select ( time_t  msec_timeout  )  [inline, inherited]

Return true if any of the requested features are true on the stream.

If msec_timeout < 0, waits forever (bad idea!). ==0, does not wait. Otherwise, waits for up to msec_timeout milliseconds.

**NOTE** select() is _not_ virtual! To change the select() behaviour of a stream, override the pre_select() and/or post_select() functions.

This version of select() sets forceable==true, so force_select options are taken into account.

You almost always use this version of select() with callbacks, like this: if (stream.select(1000)) stream.callback();

If you want to read/write the stream in question, try using the other variant of select().

DEPRECATED. Call runonce() instead.

Definition at line 376 of file wvstream.h.

Referenced by WvStream::blocking_getline(), WvStream::continue_select(), WvModemBase::hangup(), WvStreamClone::post_select(), WvFdStream::post_select(), and WvStream::runonce().

bool WvStream::select ( time_t  msec_timeout,
bool  readable,
bool  writable,
bool  isex = false 
) [inline, inherited]

This version of select() sets forceable==false, so we use the exact readable/writable/isexception options provided.

You normally use this variant of select() when deciding whether you should read/write a particular stream. For example:

if (stream.select(1000, true, false)) len = stream.read(buf, sizeof(buf));

This variant of select() is probably not what you want with most WvStreamLists, unless you know exactly what you're doing.

WARNING: the difference between the one-parameter and multi-parameter versions of select() is *incredibly* confusing. Make sure you use the right one!

DEPRECATED. Call isreadable() or iswritable() instead, if msec_timeout was going to be zero. Other values of msec_timeout are not really recommended anyway.

Definition at line 415 of file wvstream.h.

void WvStream::runonce ( time_t  msec_timeout = -1  )  [inline, inherited]

Exactly the same as: if (select(timeout)) callback();.

...except that the above is deprecated, because it assumes callbacks aren't called automatically and that the return value of one-parameter select() is actually meaningful.

Update your main loop to call runonce() instead of the above.

Almost all modern programs should use msec_timeout = -1.

Definition at line 391 of file wvstream.h.

References WvStream::callback(), and WvStream::select().

IWvStream::SelectRequest WvStream::get_select_request (  )  [inherited]

Use get_select_request() to save the current state of the selection state of this stream.

That way, you can call force_select() and undo_force_select() to restore this properly.

Definition at line 990 of file wvstream.cc.

void WvStream::force_select ( bool  readable,
bool  writable,
bool  isexception = false 
) [inherited]

Use force_select() to force one or more particular modes (readable, writable, or isexception) to true when selecting on this stream.

If an option is set 'true', we will select on that option when someone does a select(). If it's set 'false', we don't change its force status. (To de-force something, use undo_force_select().)

Definition at line 996 of file wvstream.cc.

Referenced by WvStreamClone::WvStreamClone().

void WvStream::undo_force_select ( bool  readable,
bool  writable,
bool  isexception = false 
) [inherited]

Undo a previous force_select() - ie.

un-forces the options which are 'true', and leaves the false ones alone.

Definition at line 1007 of file wvstream.cc.

bool WvStream::continue_select ( time_t  msec_timeout  )  [inherited]

return to the caller from execute(), but don't really return exactly; this uses WvCont::yield() to return to the caller of callback() without losing our place in execute() itself.

So, next time someone calls callback(), it will be as if continue_select() returned.

NOTE: execute() will won't be called recursively this way, but any other member function might get called, or member variables changed, or the state of the world updated while continue_select() runs. Don't assume that nothing has changed after a call to continue_select().

NOTE 2: if you're going to call continue_select(), you should set uses_continue_select=true before the first call to callback(). Otherwise your WvCont won't get created.

NOTE 3: if msec_timeout >= 0, this uses WvStream::alarm().

Definition at line 1058 of file wvstream.cc.

References WvStream::alarm(), WvStream::alarm_was_ticking, WvStream::select(), WvStream::uses_continue_select, and WvCont::yield().

Referenced by WvStream::blocking_getline().

IWvStreamCallback WvStream::setreadcallback ( IWvStreamCallback  _callback  )  [inherited]

Sets a callback to be invoked when the stream is readable.

Definition at line 1113 of file wvstream.cc.

IWvStreamCallback WvStream::setwritecallback ( IWvStreamCallback  _callback  )  [inherited]

Sets a callback to be invoked when the stream is writable.

Definition at line 1123 of file wvstream.cc.

IWvStreamCallback WvStream::setexceptcallback ( IWvStreamCallback  _callback  )  [inherited]

Sets a callback to be invoked when the stream is in exception state.

Definition at line 1133 of file wvstream.cc.

IWvStreamCallback WvStream::setclosecallback ( IWvStreamCallback  _callback  )  [inherited]

Sets a callback to be invoked on close().

Definition at line 1143 of file wvstream.cc.

References WvStream::_callback(), and WvStream::isok().

void WvStream::noautoforward (  )  [inherited]

Stops autoforwarding.

Definition at line 330 of file wvstream.cc.

References WvStream::read_requires_writable, and WvStream::setcallback().

void WvStream::callback (  )  [virtual, inherited]

if the stream has a callback function defined, call it now.

otherwise call execute().

Definition at line 364 of file wvstream.cc.

References WvStream::_callback(), WvStream::_callwrap(), WvStream::alarm_remaining(), WvStream::alarm_was_ticking, WvStream::personal_stack_size, and WvStream::uses_continue_select.

Referenced by UniClientGen::flush_buffers(), and WvStream::runonce().

void WvStream::alarm ( time_t  msec_timeout  )  [inherited]

set an alarm, ie.

select() will return true after this many ms. The alarm is cleared when callback() is called.

Definition at line 1018 of file wvstream.cc.

Referenced by WvStream::continue_select(), WvSubProcQueueStream::execute(), and WvUnixDGSocket::post_select().

size_t WvStream::print ( WVSTRING_FORMAT_DECL   )  [inline, inherited]

preformat and write() a string.

Definition at line 546 of file wvstream.h.

References WvStream::write().


Member Data Documentation

WvEncoderChain WvEncoderStream::readchain [inherited]

Encoder chain through which input data is passed.

Definition at line 47 of file wvencoderstream.h.

Referenced by WvEncoderStream::finish_read(), and WvEncoderStream::flush_read().

WvEncoderChain WvEncoderStream::writechain [inherited]

Encoder chain through which output data is passed.

Definition at line 50 of file wvencoderstream.h.

size_t WvEncoderStream::min_readsize [inherited]

Controls the minimum number of unencoded bytes the encoder should try to read at once from the underlying stream, to optimize performance of block-oriented protocols.

This is not the same as queuemin() which guarantees how much encoded input must be generated before select() returns true. if 0, the encoder will only read whatever is specified in uread().

NOTE: if you plan to append a new encoder to the readchain after doing read(), you should always use read() with only 1 byte at a time, or some extra data will end up in inbuf and not pass through the newly- added encoder. Remember that getline() also calls read(). The purpose of min_readsize is to make these one-byte read() calls more efficient, because the *underlying* stream can still read lots of bytes, as long as we only pass single bytes down to the WvEncoderStream.

If you don't plan to add new encoders to readchain from now on, you can give larger sizes to read() or getline(), and thus min_readsize is unnecessary.

Definition at line 73 of file wvencoderstream.h.

Referenced by WvEncoderStream::uread(), and WvEncoderStream::WvEncoderStream().

bool WvStream::uses_continue_select [inherited]

If this is set, enables the use of continue_select().

Definition at line 45 of file wvstream.h.

Referenced by WvStream::blocking_getline(), WvStream::callback(), WvStream::continue_getline(), and WvStream::continue_select().

size_t WvStream::personal_stack_size [inherited]

Specifies the stack size to reserve for continue_select().

Definition at line 48 of file wvstream.h.

Referenced by WvStream::callback().

bool WvStream::stop_read [inherited]

True if noread()/nowrite()/close() have been called, respectively.

Definition at line 57 of file wvstream.h.

Referenced by WvStream::blocking_getline(), WvSSLStream::close(), and WvSSLStream::uread().


The documentation for this class was generated from the following file:
Generated on Thu Jan 24 16:51:02 2008 for WvStreams by  doxygen 1.5.4