/**
* Partial chunks are not valid in X12. Encode using ASCII instead, using
* an implied unlatch if there is exactly one ascii codeword and one symbol
* codeword remaining. Otherwise use explicit unlatch.
*/
static void
CompletePartialX12(DmtxEncodeStream *stream, DmtxByteList *valueList, int sizeIdxRequest)
{
int i;
int sizeIdx;
int symbolRemaining;
DmtxPassFail passFail;
DmtxByte outputTmpStorage[2];
DmtxByteList outputTmp;
if(stream->currentScheme != DmtxSchemeX12)
{
StreamMarkFatal(stream, DmtxErrorUnexpectedScheme);
return;
}
/* Should have exactly one or two input values left */
assert(valueList->length == 1 || valueList->length == 2);
/* Roll back input progress */
for(i = 0; i < valueList->length; i++)
{
StreamInputAdvancePrev(stream); CHKERR;
}
/* Encode up to 2 codewords to a temporary stream */
outputTmp = EncodeTmpRemainingInAscii(stream, outputTmpStorage,
sizeof(outputTmpStorage), &passFail);
sizeIdx = FindSymbolSize(stream->output->length + 1, sizeIdxRequest);
symbolRemaining = GetRemainingSymbolCapacity(stream->output->length, sizeIdx);
if(outputTmp.length == 1 && symbolRemaining == 1)
{
/* End of symbol condition (XXX) */
EncodeChangeScheme(stream, DmtxSchemeAscii, DmtxUnlatchImplicit); CHKERR;
AppendValueAscii(stream, outputTmp.b[0]); CHKERR;
/* Register progress since encoding happened outside normal path */
stream->inputNext = stream->input->length;
StreamMarkComplete(stream, sizeIdx);
}
else
{
/* Finish in ASCII (XXX) */
EncodeChangeScheme(stream, DmtxSchemeAscii, DmtxUnlatchExplicit); CHKERR;
for(i = 0; i < outputTmp.length; i++)
AppendValueAscii(stream, outputTmp.b[i]); CHKERR;
sizeIdx = FindSymbolSize(stream->output->length, sizeIdxRequest);
PadRemainingInAscii(stream, sizeIdx);
/* Register progress since encoding happened outside normal path */
stream->inputNext = stream->input->length;
StreamMarkComplete(stream, sizeIdx);
}
}
static void
CompleteIfDoneAscii(DmtxEncodeStream *stream, int sizeIdxRequest)
{
int sizeIdx;
if(stream->status == DmtxStatusComplete)
return;
if(!StreamInputHasNext(stream))
{
sizeIdx = FindSymbolSize(stream->output->length, sizeIdxRequest); CHKSIZE;
PadRemainingInAscii(stream, sizeIdx); CHKERR;
StreamMarkComplete(stream, sizeIdx);
}
}
/**
* check remaining symbol capacity and remaining codewords
* if the chain can finish perfectly at the end of symbol data words there is a
* special one-byte length header value that can be used (i think ... read the
* spec again before commiting to anything)
*/
static void
CompleteIfDoneBase256(DmtxEncodeStream *stream, int sizeIdxRequest)
{
int sizeIdx;
int headerByteCount, outputLength, symbolRemaining;
if(stream->status == DmtxStatusComplete)
return;
if(!StreamInputHasNext(stream))
{
headerByteCount = stream->outputChainWordCount - stream->outputChainValueCount;
assert(headerByteCount == 1 || headerByteCount == 2);
/* Check for special case where every last symbol word is used */
if(headerByteCount == 2)
{
/* Find symbol size as if headerByteCount was only 1 */
outputLength = stream->output->length - 1;
sizeIdx = FindSymbolSize(outputLength, sizeIdxRequest); /* No CHKSIZE */
if(sizeIdx != DmtxUndefined)
{
symbolRemaining = GetRemainingSymbolCapacity(outputLength, sizeIdx);
if(symbolRemaining == 0)
{
/* Perfect fit -- complete encoding */
UpdateBase256ChainHeader(stream, sizeIdx); CHKERR;
StreamMarkComplete(stream, sizeIdx);
return;
}
}
}
/* Normal case */
sizeIdx = FindSymbolSize(stream->output->length, sizeIdxRequest); CHKSIZE;
EncodeChangeScheme(stream, DmtxSchemeAscii, DmtxUnlatchImplicit);
PadRemainingInAscii(stream, sizeIdx);
StreamMarkComplete(stream, sizeIdx);
}
}
/**
* Complete C40/Text/X12 encoding if it matches a known end-of-symbol condition.
*
* Term Trip Symbol Codeword
* Cond Size Remain Sequence
* ---- ---- ------ -----------------------
* (a) 3 2 Special case
* - - UNLATCH [PAD]
*/
static void
CompleteIfDoneCTX(DmtxEncodeStream *stream, int sizeIdxRequest)
{
int sizeIdx;
int symbolRemaining;
if(stream->status == DmtxStatusComplete)
return;
if(!StreamInputHasNext(stream))
{
sizeIdx = FindSymbolSize(stream->output->length, sizeIdxRequest); CHKSIZE;
symbolRemaining = GetRemainingSymbolCapacity(stream->output->length, sizeIdx);
if(symbolRemaining > 0)
{
EncodeChangeScheme(stream, DmtxSchemeAscii, DmtxUnlatchExplicit); CHKERR;
PadRemainingInAscii(stream, sizeIdx);
}
StreamMarkComplete(stream, sizeIdx);
}
}
/**
* The remaining values can exist in 3 possible cases:
*
* a) 1 C40/Text/X12 remaining == 1 data
* b) 2 C40/Text/X12 remaining == 1 shift + 1 data
* c) 2 C40/Text/X12 remaining == 1 data + 1 data
*
* To distinguish between cases (b) and (c), encode the final input value to
* C40/Text/X12 in a temporary location and check the resulting length. If
* it expands to multiple values it represents (b); otherwise it is (c). This
* accounts for both shift and upper shift conditions.
*
* Note that in cases (a) and (c) the final C40/Text/X12 value encoded in the
* previous chunk may have been a shift value, but this will be ignored by
* the decoder due to the implicit shift to ASCII. <-- what if symbol is much
* larger though?
*
* Term Value Symbol Codeword
* Cond Count Remain Sequence
* ---- ------- ------ ------------------------
* (b) C40 2 2 C40+C40+0
* (d) ASCII 1 1 ASCII (implicit unlatch)
* (c) ASCII 1 2 UNLATCH ASCII
* - - UNLATCH (finish ASCII)
*/
static void
CompletePartialC40Text(DmtxEncodeStream *stream, DmtxByteList *valueList, int sizeIdxRequest)
{
int i;
int sizeIdx1, sizeIdx2;
int symbolRemaining1, symbolRemaining2;
DmtxPassFail passFail;
DmtxByte inputValue;
DmtxByte outputTmpStorage[4];
DmtxByteList outputTmp = dmtxByteListBuild(outputTmpStorage, sizeof(outputTmpStorage));
if(stream->currentScheme != DmtxSchemeC40 && stream->currentScheme != DmtxSchemeText)
{
StreamMarkFatal(stream, DmtxErrorUnexpectedScheme);
return;
}
/* Should have exactly one or two input values left */
assert(valueList->length == 1 || valueList->length == 2);
sizeIdx1 = FindSymbolSize(stream->output->length + 1, sizeIdxRequest);
sizeIdx2 = FindSymbolSize(stream->output->length + 2, sizeIdxRequest);
symbolRemaining1 = GetRemainingSymbolCapacity(stream->output->length, sizeIdx1);
symbolRemaining2 = GetRemainingSymbolCapacity(stream->output->length, sizeIdx2);
if(valueList->length == 2 && symbolRemaining2 == 2)
{
/* End of symbol condition (b) -- Use Shift1 to pad final list value */
dmtxByteListPush(valueList, DmtxValueCTXShift1, &passFail); CHKPASS;
AppendValuesCTX(stream, valueList); CHKERR;
StreamMarkComplete(stream, sizeIdx2);
}
else
{
/*
* Rollback progress of previously consumed input value(s) since ASCII
* encoder will be used to finish the symbol. 2 rollbacks are needed if
* valueList holds 2 data words (i.e., not shifts or upper shifts).
*/
StreamInputAdvancePrev(stream); CHKERR;
inputValue = StreamInputPeekNext(stream); CHKERR;
/* Test-encode most recently consumed input value to C40/Text/X12 */
PushCTXValues(&outputTmp, inputValue, stream->currentScheme, &passFail);
if(valueList->length == 2 && outputTmp.length == 1)
StreamInputAdvancePrev(stream); CHKERR;
/* Re-use outputTmp to hold ASCII representation of 1-2 input values */
/* XXX Refactor how the DmtxByteList is passed back here */
outputTmp = EncodeTmpRemainingInAscii(stream, outputTmpStorage,
sizeof(outputTmpStorage), &passFail);
if(passFail == DmtxFail)
{
StreamMarkFatal(stream, DmtxErrorUnknown);
return;
}
if(outputTmp.length == 1 && symbolRemaining1 == 1)
{
/* End of symbol condition (d) */
EncodeChangeScheme(stream, DmtxSchemeAscii, DmtxUnlatchImplicit); CHKERR;
AppendValueAscii(stream, outputTmp.b[0]); CHKERR;
/* Register progress since encoding happened outside normal path */
stream->inputNext = stream->input->length;
StreamMarkComplete(stream, sizeIdx1);
}
else
{
/* Finish in ASCII (c) */
EncodeChangeScheme(stream, DmtxSchemeAscii, DmtxUnlatchExplicit); CHKERR;
for(i = 0; i < outputTmp.length; i++)
AppendValueAscii(stream, outputTmp.b[i]); CHKERR;
sizeIdx1 = FindSymbolSize(stream->output->length, sizeIdxRequest);
PadRemainingInAscii(stream, sizeIdx1);
/* Register progress since encoding happened outside normal path */
stream->inputNext = stream->input->length;
StreamMarkComplete(stream, sizeIdx1);
}
}
}
