diff options
author | dgp <dgp@noemail.net> | 2014-11-03 20:39:25 (GMT) |
---|---|---|
committer | dgp <dgp@noemail.net> | 2014-11-03 20:39:25 (GMT) |
commit | 216059c5908a46ce108095cf7696b22f37c71fc9 (patch) | |
tree | bb8f9550afea449e68a345bf05d0b5a0f8d7f37b | |
parent | 19a10973fa9e2c8c6540d3188ab53573a8a9f954 (diff) | |
download | tcl-216059c5908a46ce108095cf7696b22f37c71fc9.zip tcl-216059c5908a46ce108095cf7696b22f37c71fc9.tar.gz tcl-216059c5908a46ce108095cf7696b22f37c71fc9.tar.bz2 |
[5adc350683] Reworked the management of the EOF states to re-enable the
ability to read beyond EOF. Plenty of assert()s to keep thing from going
off track again.
FossilOrigin-Name: 77bf4ea5937aacbe78acc5222776eabf69e43065
-rw-r--r-- | generic/tclIO.c | 182 |
1 files changed, 139 insertions, 43 deletions
diff --git a/generic/tclIO.c b/generic/tclIO.c index c55c118..b3af1f5 100644 --- a/generic/tclIO.c +++ b/generic/tclIO.c @@ -3977,6 +3977,21 @@ Tcl_GetsObj( } /* + * If we're sitting ready to read the eofchar, there's no need to + * do it. + */ + + if (GotFlag(statePtr, CHANNEL_STICKY_EOF)) { + SetFlag(statePtr, CHANNEL_EOF); + assert( statePtr->inputEncodingFlags & TCL_ENCODING_END ); + assert( !GotFlag(statePtr, CHANNEL_BLOCKED|INPUT_SAW_CR) ); + + /* TODO: Do we need this? */ + UpdateInterest(chanPtr); + return -1; + } + + /* * A binary version of Tcl_GetsObj. This could also handle encodings that * are ascii-7 pure (iso8859, utf-8, ...) with a final encoding conversion * done on objPtr. @@ -4194,6 +4209,7 @@ Tcl_GetsObj( dstEnd = eof; SetFlag(statePtr, CHANNEL_EOF | CHANNEL_STICKY_EOF); statePtr->inputEncodingFlags |= TCL_ENCODING_END; + ResetFlag(statePtr, CHANNEL_BLOCKED|INPUT_SAW_CR); } if (GotFlag(statePtr, CHANNEL_EOF)) { skip = 0; @@ -4307,6 +4323,13 @@ Tcl_GetsObj( */ done: + assert(!GotFlag(statePtr, CHANNEL_EOF) + || GotFlag(statePtr, CHANNEL_STICKY_EOF) + || Tcl_InputBuffered((Tcl_Channel)chanPtr) == 0); + + assert( !(GotFlag(statePtr, CHANNEL_EOF|CHANNEL_BLOCKED) + == (CHANNEL_EOF|CHANNEL_BLOCKED)) ); + /* * Regenerate the top channel, in case it was changed due to * self-modifying reflected transforms. @@ -4330,6 +4353,11 @@ Tcl_GetsObj( * end-of-line or end-of-file has been seen. Bytes read from the input * channel return as a ByteArray obj. * + * WARNING! The notion of "binary" used here is different from + * notions of "binary" used in other places. In particular, this + * "binary" routine may be called when an -eofchar is set on the + * channel. + * * Results: * Number of characters accumulated in the object or -1 if error, * blocked, or EOF. If -1, use Tcl_GetErrno() to retrieve the POSIX error @@ -4416,15 +4444,15 @@ TclGetsObjBinary( } } else { /* - * There's something already in the buffer. If - * CHANNEL_STICKY_EOF is set we know that something begins - * with the eofchar. Otherwise, if CHANNEL_EOF is set, we - * know some earlier inputproc call returned zero bytes when - * we were trying to get more bytes to put in the buffer. - * which means..... ???? Place to probe with tests. - */ - assert (GotFlag(statePtr, CHANNEL_STICKY_EOF) - || !GotFlag(statePtr, CHANNEL_EOF) ); + * Incoming CHANNEL_STICKY_EOF is filtered out on entry. + * A new CHANNEL_STICKY_EOF set in this routine leads to + * return before coming back here. When we are not dealing + * with CHANNEL_STICKY_EOF, a CHANNEL_EOF implies an + * empty buffer. Here the buffer is non-empty so we know + * we're a non-EOF */ + + assert ( !GotFlag(statePtr, CHANNEL_STICKY_EOF) ); + assert ( !GotFlag(statePtr, CHANNEL_EOF) ); } dst = (unsigned char *) RemovePoint(bufPtr); @@ -4466,6 +4494,7 @@ TclGetsObjBinary( SetFlag(statePtr, CHANNEL_EOF | CHANNEL_STICKY_EOF); statePtr->inputEncodingFlags |= TCL_ENCODING_END; + ResetFlag(statePtr, CHANNEL_BLOCKED|INPUT_SAW_CR); } if (GotFlag(statePtr, CHANNEL_EOF)) { skip = 0; @@ -4575,6 +4604,11 @@ TclGetsObjBinary( */ done: + assert(!GotFlag(statePtr, CHANNEL_EOF) + || GotFlag(statePtr, CHANNEL_STICKY_EOF) + || Tcl_InputBuffered((Tcl_Channel)chanPtr) == 0); + assert( !(GotFlag(statePtr, CHANNEL_EOF|CHANNEL_BLOCKED) + == (CHANNEL_EOF|CHANNEL_BLOCKED)) ); UpdateInterest(chanPtr); TclChannelRelease((Tcl_Channel)chanPtr); return copiedTotal; @@ -4706,8 +4740,16 @@ FilterInputBytes( return -1; } } else { - assert( GotFlag(statePtr, CHANNEL_STICKY_EOF) - || !GotFlag(statePtr, CHANNEL_EOF) ); + /* + * Incoming CHANNEL_STICKY_EOF is filtered out on entry. + * A new CHANNEL_STICKY_EOF set in this routine leads to + * return before coming back here. When we are not dealing + * with CHANNEL_STICKY_EOF, a CHANNEL_EOF implies an + * empty buffer. Here the buffer is non-empty so we know + * we're a non-EOF */ + + assert ( !GotFlag(statePtr, CHANNEL_STICKY_EOF) ); + assert ( !GotFlag(statePtr, CHANNEL_EOF) ); } /* @@ -5201,19 +5243,11 @@ DoReadChars( ChannelState *statePtr = chanPtr->state; /* State info for channel */ ChannelBuffer *bufPtr; - int factor, copied, copiedNow, result; - Tcl_Encoding encoding; + int copied, copiedNow, result; + Tcl_Encoding encoding = statePtr->encoding; int binaryMode; #define UTF_EXPANSION_FACTOR 1024 - - /* - * This operation should occur at the top of a channel stack. - */ - - chanPtr = statePtr->topChanPtr; - encoding = statePtr->encoding; - factor = UTF_EXPANSION_FACTOR; - TclChannelPreserve((Tcl_Channel)chanPtr); + int factor = UTF_EXPANSION_FACTOR; binaryMode = (encoding == NULL) && (statePtr->inputTranslation == TCL_TRANSLATE_LF) @@ -5237,6 +5271,36 @@ DoReadChars( } } + /* + * Early out when next read will see eofchar. + * + * NOTE: See DoRead for argument that it's a bug (one we're keeping) + * to have this escape before the one for zero-char read request. + */ + + if (GotFlag(statePtr, CHANNEL_STICKY_EOF)) { + SetFlag(statePtr, CHANNEL_EOF); + assert( statePtr->inputEncodingFlags & TCL_ENCODING_END ); + assert( !GotFlag(statePtr, CHANNEL_BLOCKED|INPUT_SAW_CR) ); + + UpdateInterest(chanPtr); + return 0; + } + + /* Special handling for zero-char read request. */ + if (toRead == 0) { + ResetFlag(statePtr, CHANNEL_BLOCKED|CHANNEL_EOF); + UpdateInterest(chanPtr); + return 0; + } + + /* + * This operation should occur at the top of a channel stack. + */ + + chanPtr = statePtr->topChanPtr; + TclChannelPreserve((Tcl_Channel)chanPtr); + /* Must clear the BLOCKED flag here since we check before reading */ ResetFlag(statePtr, CHANNEL_BLOCKED|CHANNEL_EOF); for (copied = 0; (unsigned) toRead > 0; ) { @@ -5314,6 +5378,11 @@ DoReadChars( * Update the notifier state so we don't block while there is still data * in the buffers. */ + assert(!GotFlag(statePtr, CHANNEL_EOF) + || GotFlag(statePtr, CHANNEL_STICKY_EOF) + || Tcl_InputBuffered((Tcl_Channel)chanPtr) == 0); + assert( !(GotFlag(statePtr, CHANNEL_EOF|CHANNEL_BLOCKED) + == (CHANNEL_EOF|CHANNEL_BLOCKED)) ); UpdateInterest(chanPtr); TclChannelRelease((Tcl_Channel)chanPtr); return copied; @@ -5922,7 +5991,7 @@ TranslateInputEOL( SetFlag(statePtr, CHANNEL_EOF | CHANNEL_STICKY_EOF); statePtr->inputEncodingFlags |= TCL_ENCODING_END; - ResetFlag(statePtr, INPUT_SAW_CR); + ResetFlag(statePtr, CHANNEL_BLOCKED|INPUT_SAW_CR); } } @@ -6132,6 +6201,14 @@ GetInput( ChannelState *statePtr = chanPtr->state; /* State info for channel */ + /* + * Verify that all callers know better than to call us when + * it's recorded that the next char waiting to be read is the + * eofchar. + */ + + assert( !GotFlag(statePtr, CHANNEL_STICKY_EOF) ); + /* * Prevent reading from a dead channel -- a channel that has been closed * but not yet deallocated, which can happen if the exit handler for @@ -6143,21 +6220,6 @@ GetInput( return EINVAL; } - /* - * Strangely named "STICKY_EOF" really means we've seen the - * eofchar for this channel, and nothing since has reset it. - * (changed the eofchar, [seek]ed to a new offset, etc.) So, - * we know we're still poised to read that eofchar again, and - * there's no need to actually do it. - */ - - if (GotFlag(statePtr, CHANNEL_STICKY_EOF)) { - assert(statePtr->inEofChar); - assert(statePtr->inQueueHead); - assert(RemovePoint(statePtr->inQueueHead)[0] == statePtr->inEofChar); - return 0; - } - /* * WARNING: There was once a comment here claiming that it was * a bad idea to make another call to the inputproc of a channel @@ -6185,6 +6247,7 @@ GetInput( if (chanPtr->inQueueHead != NULL) { + /* TODO: Tests to cover this. */ assert(statePtr->inQueueHead == NULL); statePtr->inQueueHead = chanPtr->inQueueHead; @@ -6215,6 +6278,7 @@ GetInput( * Check the actual buffersize against the requested buffersize. * Saved buffers of the wrong size are squashed. This is done * to honor dynamic changes of the buffersize made by the user. + * TODO: Tests to cover this. */ if ((bufPtr != NULL) @@ -6758,9 +6822,7 @@ Tcl_Eof( ChannelState *statePtr = ((Channel *) chan)->state; /* State of real channel structure. */ - return (GotFlag(statePtr, CHANNEL_STICKY_EOF) || - (GotFlag(statePtr, CHANNEL_EOF) && - (Tcl_InputBuffered(chan) == 0))) ? 1 : 0; + return GotFlag(statePtr, CHANNEL_EOF) ? 1 : 0; } /* @@ -8882,6 +8944,36 @@ DoRead( ChannelState *statePtr = chanPtr->state; char *p = dst; + assert (bytesToRead >= 0); + + /* + * Early out when we know a read will get the eofchar. + * + * NOTE: This seems to be a bug. The special handling for + * a zero-char read request ought to come first. As coded + * the EOF due to eofchar has distinguishing behavior from + * the EOF due to reported EOF on the underlying device, and + * that seems undesirable. However recent history indicates + * that new inconsistent behavior in a patchlevel has problems + * too. Keep on keeping on for now. + */ + + if (GotFlag(statePtr, CHANNEL_STICKY_EOF)) { + SetFlag(statePtr, CHANNEL_EOF); + assert( statePtr->inputEncodingFlags & TCL_ENCODING_END ); + assert( !GotFlag(statePtr, CHANNEL_BLOCKED|INPUT_SAW_CR) ); + + UpdateInterest(chanPtr); + return 0; + } + + /* Special handling for zero-char read request. */ + if (bytesToRead == 0) { + ResetFlag(statePtr, CHANNEL_BLOCKED|CHANNEL_EOF); + UpdateInterest(chanPtr); + return 0; + } + TclChannelPreserve((Tcl_Channel)chanPtr); while (bytesToRead) { /* @@ -8952,8 +9044,7 @@ DoRead( * 1) We're @EOF because we saw eof char. */ - if (statePtr->inEofChar - && RemovePoint(bufPtr)[0] == statePtr->inEofChar) { + if (GotFlag(statePtr, CHANNEL_STICKY_EOF)) { UpdateInterest(chanPtr); break; } @@ -9026,6 +9117,11 @@ DoRead( ResetFlag(statePtr, CHANNEL_BLOCKED); } + assert(!GotFlag(statePtr, CHANNEL_EOF) + || GotFlag(statePtr, CHANNEL_STICKY_EOF) + || Tcl_InputBuffered((Tcl_Channel)chanPtr) == 0); + assert( !(GotFlag(statePtr, CHANNEL_EOF|CHANNEL_BLOCKED) + == (CHANNEL_EOF|CHANNEL_BLOCKED)) ); TclChannelRelease((Tcl_Channel)chanPtr); return (int)(p - dst); } |