ICU-2314 add fromUBytesLength to .cnv file structure

X-SVN-Rev: 10203

icu4c/source/common/ucnvmbcs.c

@@ -55,9 +55,13 @@
 #define MBCS_UNROLL_SINGLE_FROM_BMP 0
 
 /*
- * _MBCSHeader versions 4
+ * _MBCSHeader versions 4.1
  * (Note that the _MBCSHeader version is in addition to the converter formatVersion.)
  *
+ * Change from version 4.0:
+ * - Replace header.reserved with header.fromUBytesLength so that all
+ *   fields in the data have length.
+ *
  * Changes from version 3 (for performance improvements):
  * - new bit distribution for state table entries
  * - reordered action codes
@@ -364,12 +368,21 @@ gb18030Ranges[13][4]={
 
 static uint32_t
 _MBCSSizeofFromUBytes(UConverterMBCSTable *mbcsTable) {
-    /* ### TODO markus 20020911 Use _MBCSHeader.reserved to store size of fromUBytes[] */
     const uint16_t *table;
 
     uint32_t st3, maxStage3;
     uint16_t st1, maxStage1, st2;
 
+    if(mbcsTable->fromUBytesLength>0) {
+        /*
+         * We _know_ the number of bytes in the fromUnicodeBytes array
+         * starting with header.version 4.1.
+         * Otherwise, below, we need to enumerate the fromUnicode
+         * trie and find the highest entry.
+         */
+        return mbcsTable->fromUBytesLength;
+    }
+
     /* Enumerate the from-Unicode trie table to find the highest stage 3 index. */
     table=mbcsTable->fromUnicodeTable;
     maxStage3=0;
@@ -621,6 +634,7 @@ _MBCSLoad(UConverterSharedData *sharedData,
 
     mbcsTable->fromUnicodeTable=(const uint16_t *)(raw+header->offsetFromUTable);
     mbcsTable->fromUnicodeBytes=(const uint8_t *)(raw+header->offsetFromUBytes);
+    mbcsTable->fromUBytesLength=header->fromUBytesLength;
     mbcsTable->outputType=(uint8_t)header->flags;
 
     /* make sure that the output type is known */

icu4c/source/common/ucnvmbcs.h

@@ -128,6 +128,7 @@ typedef struct UConverterMBCSTable {
     const uint16_t *fromUnicodeTable;
     const uint8_t *fromUnicodeBytes;
     uint8_t *swapLFNLFromUnicodeBytes; /* for swaplfnl */
+    uint32_t fromUBytesLength;
     uint8_t outputType, unicodeMask;
 
     /* converter name for swaplfnl */
@@ -147,7 +148,7 @@ typedef struct UConverterMBCSTable {
  *  6   flags, bits:
  *          31.. 8 reserved
  *           7.. 0 outputType
- *  7   reserved
+ *  7   fromUBytesLength -- header.version 4.1 (ICU 2.4) and higher
  *
  * stateTable[countStates][256];
  *
@@ -170,7 +171,7 @@ typedef struct {
              offsetFromUTable,
              offsetFromUBytes,
              flags,
-             reserved;
+             fromUBytesLength;
 } _MBCSHeader;
 
 /**

icu4c/source/tools/makeconv/genmbcs.c

@@ -123,6 +123,7 @@ MBCSInit(MBCSData *mbcsData, uint8_t maxCharLength) {
     mbcsData->newConverter.write=MBCSWrite;
 
     mbcsData->header.version[0]=4;
+    mbcsData->header.version[1]=1;
     mbcsData->stateFlags[0]=MBCS_STATE_FLAG_DIRECT;
     mbcsData->stage2Top=MBCS_STAGE_2_FIRST_ASSIGNED; /* after stage 1 and one all-unassigned stage 2 block */
     mbcsData->stage3Top=16*maxCharLength; /* after one all-unassigned stage 3 block */
@@ -1715,6 +1716,7 @@ MBCSWrite(NewConverter *cnvData, const UConverterStaticData *staticData, UNewDat
         mbcsData->header.offsetFromUTable+
         stage1Top*2+
         mbcsData->stage2Top;
+    mbcsData->header.fromUBytesLength=mbcsData->stage3Top;
 
     /* write the MBCS data */
     udata_writeBlock(pData, &mbcsData->header, sizeof(_MBCSHeader));
@@ -1730,5 +1732,5 @@ MBCSWrite(NewConverter *cnvData, const UConverterStaticData *staticData, UNewDat
     udata_writeBlock(pData, mbcsData->fromUBytes, mbcsData->stage3Top);
 
     /* return the number of bytes that should have been written */
-    return mbcsData->header.offsetFromUBytes+mbcsData->stage3Top;
+    return mbcsData->header.offsetFromUBytes+mbcsData->header.fromUBytesLength;
 }