TIP#287 IMPLEMENTATION

        * doc/chan.n:           New subcommand [chan pending].
        * generic/tclBasic.c:   Thanks to Michael Cleverly for proposal
        * generic/tclInt.h:     and implementation.
        * generic/tclIOCmd.c:
        * library/init.tcl:
        * tests/chan.test:
        * tests/ioCmd.test:

9 files changed, 220 insertions, 11 deletions

diff --git a/ChangeLog b/ChangeLog
index 3b93ebb..b19360d 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,5 +1,15 @@
 2006-12-01  Don Porter  <dgp@users.sourceforge.net>
 
+	TIP#287 IMPLEMENTATION
+
+	* doc/chan.n:		New subcommand [chan pending].
+	* generic/tclBasic.c:	Thanks to Michael Cleverly for proposal
+	* generic/tclInt.h:	and implementation.
+	* generic/tclIOCmd.c:
+	* library/init.tcl:
+	* tests/chan.test:
+	* tests/ioCmd.test:
+
 	TIP#298 IMPLEMENTATION
 
 	* generic/tcl.decls: Tcl_GetBignumAndClearObj -> Tcl_TakeBignumFromObj.
diff --git a/doc/chan.n b/doc/chan.n
index 6b912c1..9e51251 100644
--- a/doc/chan.n
+++ b/doc/chan.n
@@ -4,7 +4,7 @@
 '\" See the file "license.terms" for information on usage and redistribution
 '\" of this file, and for a DISCLAIMER OF ALL WARRANTIES.
 '\"
-'\" RCS: @(#) $Id: chan.n,v 1.6 2006/11/16 09:34:17 dkf Exp $
+'\" RCS: @(#) $Id: chan.n,v 1.7 2006/12/01 15:55:44 dgp Exp $
 .so man.macros
 .TH chan n 8.5 Tcl "Tcl Built-In Commands"
 .BS
@@ -493,6 +493,16 @@ Produces a list of all channel names. If \fIpattern\fR is specified,
 only those channel names that match it (according to the rules of
 \fBstring match\fR) will be returned.
 .TP
+\fBchan pending \fImode channelId\fR
+.
+Depending on whether \fImode\fr is "input" or "output", returns the number of 
+bytes of input or output (respectively) currently buffered 
+internally for \fIchannelId\fr (especially useful in a readable event 
+callback to impose application-specific limits on input line lengths to avoid
+a potential denial-of-service attack where a hostile user crafts
+an extremely long line that exceeds the available memory to buffer it).
+Returns -1 if the channel was not opened for the mode in question.
+.TP
 \fBchan postevent \fIchannelId eventSpec\fR
 .
 This subcommand is used by command handlers specified with \fBchan
diff --git a/generic/tclBasic.c b/generic/tclBasic.c
index 5df0a81..a3fb387 100644
--- a/generic/tclBasic.c
+++ b/generic/tclBasic.c
@@ -13,7 +13,7 @@
  * See the file "license.terms" for information on usage and redistribution of
  * this file, and for a DISCLAIMER OF ALL WARRANTIES.
  *
- * RCS: @(#) $Id: tclBasic.c,v 1.222 2006/11/29 15:01:26 dgp Exp $
+ * RCS: @(#) $Id: tclBasic.c,v 1.223 2006/12/01 15:55:44 dgp Exp $
  */
 
 #include "tclInt.h"
@@ -574,6 +574,10 @@ Tcl_CreateInterp(void)
     Tcl_CreateObjCommand(interp, "::tcl::chan::rPostevent",
 	    TclChanPostEventObjCmd, (ClientData) NULL, NULL);
 
+    /* TIP #287 */
+    Tcl_CreateObjCommand(interp, "::tcl::chan::Pending",
+	    TclChanPendingObjCmd, (ClientData) NULL, NULL);
+
     /*
      * Register the built-in functions. This is empty now that they are
      * implemented as commands in the ::tcl::mathfunc namespace.
diff --git a/generic/tclIOCmd.c b/generic/tclIOCmd.c
index 4b5974b..c2c1bb8 100644
--- a/generic/tclIOCmd.c
+++ b/generic/tclIOCmd.c
@@ -8,7 +8,7 @@
  * See the file "license.terms" for information on usage and redistribution of
  * this file, and for a DISCLAIMER OF ALL WARRANTIES.
  *
- * RCS: @(#) $Id: tclIOCmd.c,v 1.34 2006/07/20 06:17:39 das Exp $
+ * RCS: @(#) $Id: tclIOCmd.c,v 1.35 2006/12/01 15:55:44 dgp Exp $
  */
 
 #include "tclInt.h"
@@ -1619,6 +1619,74 @@ Tcl_FcopyObjCmd(
 }
 
 /*
+ *---------------------------------------------------------------------------
+ *
+ * TclChanPendingObjCmd --
+ *
+ *	This function is invoked to process the Tcl "chan pending" 
+ *	command (TIP #287). See the user documentation for details on 
+ *	what it does.
+ *
+ * Results:
+ *	A standard Tcl result.
+ *
+ * Side effects:
+ *	Sets interp's result to the number of bytes of buffered input or
+ *	output (depending on whether the first argument is "input" or
+ *	"output"), or -1 if the channel wasn't opened for that mode.
+ *
+ *---------------------------------------------------------------------------
+ */
+
+	/* ARGSUSED */
+int
+TclChanPendingObjCmd(
+    ClientData unused,		/* Not used. */
+    Tcl_Interp *interp,		/* Current interpreter. */
+    int objc,			/* Number of arguments. */
+    Tcl_Obj *CONST objv[])	/* Argument objects. */
+{
+    Tcl_Channel chan;
+    int index, mode;
+    char *arg;
+    static CONST char *options[] = {"input", "output", (char *) NULL};
+    enum options {PENDING_INPUT, PENDING_OUTPUT};
+
+    if (objc != 3) {
+	Tcl_WrongNumArgs(interp, 1, objv, "mode channelId");
+	return TCL_ERROR;
+    }
+
+    if (Tcl_GetIndexFromObj(interp, objv[1], options, "mode", 0, 
+	    &index) != TCL_OK) {
+	return TCL_ERROR;
+    }
+
+    arg = Tcl_GetString(objv[2]);
+    chan = Tcl_GetChannel(interp, arg, &mode);
+    if (chan == NULL) {
+	return TCL_ERROR;
+    }
+
+    switch ((enum options) index) {
+    case PENDING_INPUT:
+	if ((mode & TCL_READABLE) == 0) {
+	    Tcl_SetObjResult(interp, Tcl_NewIntObj(-1));
+	} else {
+	    Tcl_SetObjResult(interp, Tcl_NewIntObj(Tcl_InputBuffered(chan)));
+	}
+	return TCL_OK;
+    case PENDING_OUTPUT:
+	if ((mode & TCL_WRITABLE) == 0) {
+	    Tcl_SetObjResult(interp, Tcl_NewIntObj(-1));
+	} else {
+	    Tcl_SetObjResult(interp, Tcl_NewIntObj(Tcl_OutputBuffered(chan)));
+	}
+	return TCL_OK;
+    }
+}
+
+/*
  *----------------------------------------------------------------------
  *
  * Tcl_ChanTruncateObjCmd --
diff --git a/generic/tclInt.h b/generic/tclInt.h
index 0fb2ebf..e28e849 100644
--- a/generic/tclInt.h
+++ b/generic/tclInt.h
@@ -12,7 +12,7 @@
  * See the file "license.terms" for information on usage and redistribution of
  * this file, and for a DISCLAIMER OF ALL WARRANTIES.
  *
- * RCS: @(#) $Id: tclInt.h,v 1.299 2006/11/28 22:20:29 andreas_kupries Exp $
+ * RCS: @(#) $Id: tclInt.h,v 1.300 2006/12/01 15:55:45 dgp Exp $
  */
 
 #ifndef _TCLINT
@@ -2465,6 +2465,9 @@ MODULE_SCOPE int	Tcl_CatchObjCmd(ClientData clientData,
 MODULE_SCOPE int	Tcl_CdObjCmd(ClientData clientData,
 			    Tcl_Interp *interp, int objc,
 			    Tcl_Obj *CONST objv[]);
+MODULE_SCOPE int	TclChanPendingObjCmd(
+			    ClientData clientData, Tcl_Interp *interp,
+			    int objc, Tcl_Obj *CONST objv[]); /* TIP 287 */
 MODULE_SCOPE int	TclChanTruncateObjCmd(
 			    ClientData clientData, Tcl_Interp *interp,
 			    int objc, Tcl_Obj *CONST objv[]);
diff --git a/library/init.tcl b/library/init.tcl
index 13f6d96..838aa7b 100644
--- a/library/init.tcl
+++ b/library/init.tcl
@@ -3,7 +3,7 @@
 # Default system startup file for Tcl-based applications.  Defines
 # "unknown" procedure and auto-load facilities.
 #
-# RCS: @(#) $Id: init.tcl,v 1.89 2006/11/20 14:28:03 dkf Exp $
+# RCS: @(#) $Id: init.tcl,v 1.90 2006/12/01 15:55:45 dgp Exp $
 #
 # Copyright (c) 1991-1993 The Regents of the University of California.
 # Copyright (c) 1994-1996 Sun Microsystems, Inc.
@@ -78,6 +78,7 @@ namespace eval tcl {
     # Set up the 'chan' ensemble (TIP #208).
     namespace eval chan {
         # TIP #219. Added methods: create, postevent.
+	# TIP 287.  Added method: pending.
         namespace ensemble create -command ::chan -map {
             blocked     ::tcl::chan::blocked
             close       ::tcl::chan::close
@@ -89,6 +90,7 @@ namespace eval tcl {
             flush       ::tcl::chan::flush
             gets        ::tcl::chan::gets
             names       {::file channels}
+	    pending	::tcl::chan::Pending
             postevent   ::tcl::chan::rPostevent
             puts        ::tcl::chan::puts
             read        ::tcl::chan::read
diff --git a/libtommath/bn_mp_div.c b/libtommath/bn_mp_div.c
index d1b5c48..b80797f 100644
--- a/libtommath/bn_mp_div.c
+++ b/libtommath/bn_mp_div.c
@@ -87,6 +87,7 @@ LBL_ERR:
 
 #else
 
+#if 0
 /* Integer signed division.
  *
  * c*b + d == a, that is, c = a/b and c = a%b
@@ -236,6 +237,7 @@ int mp_div(mp_int* a, mp_int* b, mp_int* c, mp_int* d)
     return res;
 
 }
+#endif
 
 /* integer signed division. 
  * c*b + d == a [e.g. a/b, c=quotient, d=remainder]
@@ -438,5 +440,5 @@ LBL_Q:mp_clear (&q);
 #endif
 
 /* $Source: /root/tcl/repos-to-convert/tcl/libtommath/bn_mp_div.c,v $ */
-/* $Revision: 1.2 $ */
-/* $Date: 2006/12/01 00:31:32 $ */
+/* $Revision: 1.3 $ */
+/* $Date: 2006/12/01 15:55:45 $ */
diff --git a/tests/chan.test b/tests/chan.test
index f2376a3..a4d2f8e 100644
--- a/tests/chan.test
+++ b/tests/chan.test
@@ -7,7 +7,7 @@
 # See the file "license.terms" for information on usage and redistribution
 # of this file, and for a DISCLAIMER OF ALL WARRANTIES.
 #
-# RCS: @(#) $Id: chan.test,v 1.5 2005/08/24 17:56:24 andreas_kupries Exp $
+# RCS: @(#) $Id: chan.test,v 1.6 2006/12/01 15:55:45 dgp Exp $
 
 if {[lsearch [namespace children] ::tcltest] == -1} {
     package require tcltest 2
@@ -24,7 +24,7 @@ test chan-1.1 {chan command general syntax} -body {
 } -returnCodes error -result "wrong # args: should be \"chan subcommand ?argument ...?\""
 test chan-1.2 {chan command general syntax} -body {
     chan FOOBAR
-} -returnCodes error -result "unknown or ambiguous subcommand \"FOOBAR\": must be blocked, close, configure, copy, create, eof, event, flush, gets, names, postevent, puts, read, seek, tell, or truncate"
+} -returnCodes error -result "unknown or ambiguous subcommand \"FOOBAR\": must be blocked, close, configure, copy, create, eof, event, flush, gets, names, pending, postevent, puts, read, seek, tell, or truncate"
 
 test chan-2.1 {chan command: blocked subcommand} -body {
     chan blocked foo bar
@@ -96,6 +96,116 @@ test chan-15.2 {chan command: truncate subcommand} -setup {
     catch {removeFile $file}
 }
 
+# TIP 287: chan pending
+test chan-16.1 {chan command: pending subcommand} -body {
+    chan pending
+} -returnCodes error -result "wrong # args: should be \"chan pending mode channelId\""
+test chan-16.2 {chan command: pending subcommand} -body {
+    chan pending stdin
+} -returnCodes error -result "wrong # args: should be \"chan pending mode channelId\""
+test chan-16.3 {chan command: pending subcommand} -body {
+    chan pending stdin stdout stderr
+} -returnCodes error -result "wrong # args: should be \"chan pending mode channelId\""
+test chan-16.4 {chan command: pending subcommand} -body {
+    chan pending {input output} stdout
+} -returnCodes error -result "bad mode \"input output\": must be input or output"
+test chan-16.5 {chan command: pending input subcommand} -body {
+    chan pending input stdout 
+} -result -1
+test chan-16.6 {chan command: pending input subcommand} -body {
+    chan pending input stdin
+} -result 0
+test chan-16.7 {chan command: pending input subcommand} -body {
+    chan pending input FOOBAR
+} -returnCodes error -result "can not find channel named \"FOOBAR\""
+test chan-16.8 {chan command: pending input subcommand} -setup {
+    set file [makeFile {} testAvailable]
+    set f [open $file w+]
+    chan configure $f -translation lf -buffering line
+} -body {
+    chan puts $f foo
+    chan puts $f bar
+    chan puts $f baz
+    chan seek $f 0
+    chan gets $f
+    chan pending input $f
+} -result 8 -cleanup {
+    catch {chan close $f}
+    catch {removeFile $file}
+}
+test chan-16.9 {chan command: pending input subcommand} -setup {
+    proc chan-16.9-accept {sock addr port} {
+        chan configure $sock -blocking 0 -buffering line -buffersize 32
+        chan event $sock readable [list chan-16.9-readable $sock]
+    }
+
+    proc chan-16.9-readable {sock} {
+        set r [chan gets $sock line]
+        set l [string length $line]
+        set e [chan eof $sock]
+        set b [chan blocked $sock]
+        set i [chan pending input $sock]
+
+        lappend ::chan-16.9-data $r $l $e $b $i
+
+        if {$r != -1 || $e || $l || !$b || $i > 128} {
+            set data [read $sock $i]
+            lappend ::chan-16.9-data [string range $data 0 2]
+            lappend ::chan-16.9-data [string range $data end-2 end]
+            set ::chan-16.9-done 1
+        }
+    }
+
+    proc chan-16.9-client {} {
+        chan puts -nonewline $::client ABCDEFGHIJKLMNOPQRSTUVWXYZ1234567890
+        chan flush $::client
+        after 100 chan-16.9-client
+    }
+
+    set ::server [socket -server chan-16.9-accept -myaddr 127.0.0.1 0]
+    set ::client [socket 127.0.0.1 [lindex [fconfigure $::server -sockname] 2]]
+    set ::chan-16.9-data [list]
+    set ::chan-16.9-done 0
+} -body {
+    after idle chan-16.9-client 
+    vwait ::chan-16.9-done
+    set ::chan-16.9-data
+} -result {-1 0 0 1 36 -1 0 0 1 72 -1 0 0 1 108 -1 0 0 1 144 ABC 890} -cleanup {
+    catch {chan close $client}
+    catch {chan close $server}
+    rename chan-16.9-accept {}
+    rename chan-16.9-readable {}
+    rename chan-16.9-client {}
+    unset -nocomplain ::chan-16.9-data
+    unset -nocomplain ::chan-16.9-done
+    unset -nocomplain ::server
+    unset -nocomplain ::client
+}
+test chan-16.10 {chan command: pending output subcommand} -body {
+    chan pending output stdin
+} -result -1
+test chan-16.11 {chan command: pending output subcommand} -body {
+    chan pending output stdout
+} -result 0
+test chan-16.12 {chan command: pending output subcommand} -body {
+    chan pending output FOOBAR
+} -returnCodes error -result "can not find channel named \"FOOBAR\""
+test chan-16.13 {chan command: pending output subcommand} -setup {
+    set file [makeFile {} testPendingOutput]
+    set f [open $file w+]
+    chan configure $f -translation lf -buffering full -buffersize 1024
+} -body {
+    set result [list]
+    chan puts $f [string repeat x 512]
+    lappend result [chan pending output $f]
+    chan flush $f
+    lappend result [chan pending output $f]
+} -result [list 513 0] -cleanup {
+    unset -nocomplain result
+    catch {chan close $f}
+    catch {removeFile $file}
+}
+
 cleanupTests
 return
 
diff --git a/tests/ioCmd.test b/tests/ioCmd.test
index e2d8327..9a4a80d 100644
--- a/tests/ioCmd.test
+++ b/tests/ioCmd.test
@@ -13,7 +13,7 @@
 # See the file "license.terms" for information on usage and redistribution
 # of this file, and for a DISCLAIMER OF ALL WARRANTIES.
 #
-# RCS: @(#) $Id: ioCmd.test,v 1.30 2006/11/03 11:45:34 dkf Exp $
+# RCS: @(#) $Id: ioCmd.test,v 1.31 2006/12/01 15:55:45 dgp Exp $
 
 if {[lsearch [namespace children] ::tcltest] == -1} {
     package require tcltest 2
@@ -628,7 +628,7 @@ test iocmd-20.0 {chan, wrong#args} {
 test iocmd-20.1 {chan, unknown method} {
     catch {chan foo} msg
     set msg
-} {unknown or ambiguous subcommand "foo": must be blocked, close, configure, copy, create, eof, event, flush, gets, names, postevent, puts, read, seek, tell, or truncate}
+} {unknown or ambiguous subcommand "foo": must be blocked, close, configure, copy, create, eof, event, flush, gets, names, pending, postevent, puts, read, seek, tell, or truncate}
 
 # --- --- --- --------- --------- ---------
 # chan create, and method "initalize"