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author | dgp <dgp@users.sourceforge.net> | 2014-03-07 19:43:16 (GMT) |
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committer | dgp <dgp@users.sourceforge.net> | 2014-03-07 19:43:16 (GMT) |
commit | a895183137cb5e741f92353116465a9e27c432e4 (patch) | |
tree | 0044992a3d03819a91601eb70626aa42f19901c3 /generic | |
parent | a59f5c70234be1134e3752519daa601c3c850365 (diff) | |
download | tcl-a895183137cb5e741f92353116465a9e27c432e4.zip tcl-a895183137cb5e741f92353116465a9e27c432e4.tar.gz tcl-a895183137cb5e741f92353116465a9e27c432e4.tar.bz2 |
Simplify the input eof char scan. Update some comments.
Diffstat (limited to 'generic')
-rw-r--r-- | generic/tclIO.c | 64 |
1 files changed, 33 insertions, 31 deletions
diff --git a/generic/tclIO.c b/generic/tclIO.c index b0d0e32..03aac32 100644 --- a/generic/tclIO.c +++ b/generic/tclIO.c @@ -5244,7 +5244,11 @@ ReadChars( * is larger than the number of characters * available in the first buffer, only the * characters from the first buffer are - * returned. */ + * returned. The execption is when there is + * not any complete character in the first + * buffer. In that case, a recursive call + * effectively obtains chars from the + * second buffer. */ int *factorPtr) /* On input, contains a guess of how many * bytes need to be allocated to hold the * result of converting N source bytes to @@ -5259,6 +5263,15 @@ ReadChars( int savedFlags = statePtr->flags; char *dst, *src = RemovePoint(bufPtr); int dstLimit, numBytes, srcLen = BytesLeft(bufPtr); + + /* + * One src byte can yield at most one character. So when the + * number of src bytes we plan to read is less than the limit on + * character count to be read, clearly we will remain within that + * limit, and we can use the value of "srcLen" as a tighter limit + * for sizing receiving buffers. + */ + int toRead = ((unsigned) charsToRead > srcLen) ? srcLen : charsToRead; /* @@ -5569,43 +5582,32 @@ TranslateInputEOL( * characters. */ const char *srcStart, /* Source characters. */ int *dstLenPtr, /* On entry, the maximum length of output - * buffer in bytes; must be <= *srcLenPtr. On - * exit, the number of bytes actually used in - * output buffer. */ + * buffer in bytes. On exit, the number of + * bytes actually used in output buffer. */ int *srcLenPtr) /* On entry, the length of source buffer. On * exit, the number of bytes read from the * source buffer. */ { - int dstLen, srcLen, inEofChar; - const char *eof; + const char *eof = NULL; + int dstLen = *dstLenPtr; + int srcLen = *srcLenPtr; + int inEofChar = statePtr->inEofChar; - dstLen = *dstLenPtr; - - eof = NULL; - inEofChar = statePtr->inEofChar; if (inEofChar != '\0') { /* - * Find EOF in translated buffer then compress out the EOL. The source - * buffer may be much longer than the destination buffer - we only - * want to return EOF if the EOF has been copied to the destination - * buffer. + * Make sure we do not read past any logical end of channel input + * created by the presence of the input eof char. */ - const char *src, *srcMax; - - srcMax = srcStart + *srcLenPtr; - for (src = srcStart; src < srcMax; src++) { - if (*src == inEofChar) { - eof = src; - srcLen = src - srcStart; - if (srcLen < dstLen) { - dstLen = srcLen; - } - *srcLenPtr = srcLen; - break; - } + if ((eof = memchr(srcStart, inEofChar, srcLen))) { + srcLen = eof - srcStart; } } + + if (dstLen > srcLen) { + dstLen = srcLen; + } + switch (statePtr->inputTranslation) { case TCL_TRANSLATE_LF: if (dstStart != srcStart) { @@ -5635,7 +5637,7 @@ TranslateInputEOL( dst = dstStart; src = srcStart; srcEnd = srcStart + dstLen; - srcMax = srcStart + *srcLenPtr; + srcMax = srcStart + srcLen; for ( ; src < srcEnd; ) { if (*src == '\r') { @@ -5663,7 +5665,7 @@ TranslateInputEOL( dst = dstStart; src = srcStart; srcEnd = srcStart + dstLen; - srcMax = srcStart + *srcLenPtr; + srcMax = srcStart + srcLen; if ((statePtr->flags & INPUT_SAW_CR) && (src < srcMax)) { if (*src == '\n') { @@ -5692,9 +5694,10 @@ TranslateInputEOL( break; } default: - return 0; + Tcl_Panic("unknown input translation %d", statePtr->inputTranslation); } *dstLenPtr = dstLen; + *srcLenPtr = srcLen; if ((eof != NULL) && (srcStart + srcLen >= eof)) { /* @@ -5709,7 +5712,6 @@ TranslateInputEOL( return 1; } - *srcLenPtr = srcLen; return 0; } |