ICU-2235 swap serialized UTries

X-SVN-Rev: 12809

icu4c/source/common/utrie.c

@@ -23,6 +23,7 @@
 #endif
 
 #include "unicode/utypes.h"
+#include "udataswp.h"
 #include "cmemory.h"
 #include "utrie.h"
 
@@ -705,7 +706,7 @@ struct UTrieHeader {
      */
     uint32_t options;
 
-    /** indexLength is a multiple of 1024>>UTRIE_SHIFT */
+    /** indexLength is a multiple of UTRIE_SURROGATE_BLOCK_COUNT */
     int32_t indexLength;
 
     /** dataLength>=UTRIE_DATA_BLOCK_LENGTH */
@@ -905,6 +906,79 @@ utrie_unserialize(UTrie *trie, const void *data, int32_t length, UErrorCode *pEr
     }
 }
 
+/* swapping ----------------------------------------------------------------- */
+
+U_CAPI int32_t U_EXPORT2
+utrie_swap(const UDataSwapper *ds,
+           const void *inData, int32_t length, void *outData,
+           UErrorCode *pErrorCode) {
+    const UTrieHeader *inTrie;
+    UTrieHeader trie;
+    int32_t size;
+    UBool dataIs32;
+
+    if(pErrorCode==NULL || U_FAILURE(*pErrorCode)) {
+        return 0;
+    }
+    if(ds==NULL || inData==NULL || (length>=0 && outData==NULL)) {
+        *pErrorCode=U_ILLEGAL_ARGUMENT_ERROR;
+        return 0;
+    }
+
+    /* setup and swapping */
+    if(length>=0 && length<sizeof(UTrieHeader)) {
+        *pErrorCode=U_INDEX_OUTOFBOUNDS_ERROR;
+        return 0;
+    }
+
+    inTrie=(const UTrieHeader *)inData;
+    trie.signature=ds->readUInt32(inTrie->signature);
+    trie.options=ds->readUInt32(inTrie->options);
+    trie.indexLength=udata_readInt32(ds, inTrie->indexLength);
+    trie.dataLength=udata_readInt32(ds, inTrie->dataLength);
+
+    if( trie.signature!=0x54726965 ||
+        (trie.options&UTRIE_OPTIONS_SHIFT_MASK)!=UTRIE_SHIFT ||
+        ((trie.options>>UTRIE_OPTIONS_INDEX_SHIFT)&UTRIE_OPTIONS_SHIFT_MASK)!=UTRIE_INDEX_SHIFT ||
+        trie.indexLength<UTRIE_BMP_INDEX_LENGTH ||
+        (trie.indexLength&(UTRIE_SURROGATE_BLOCK_COUNT-1))!=0 ||
+        trie.dataLength<UTRIE_DATA_BLOCK_LENGTH ||
+        (trie.dataLength&(UTRIE_DATA_GRANULARITY-1))!=0 ||
+        ((trie.options&UTRIE_OPTIONS_LATIN1_IS_LINEAR)!=0 && trie.dataLength<(UTRIE_DATA_BLOCK_LENGTH+0x100))
+    ) {
+        *pErrorCode=U_INVALID_FORMAT_ERROR; /* not a UTrie */
+        return 0;
+    }
+
+    dataIs32=(UBool)((trie.options&UTRIE_OPTIONS_DATA_IS_32_BIT)!=0);
+    size=sizeof(UTrieHeader)+trie.indexLength*2+trie.dataLength*(dataIs32?4:2);
+
+    if(length>=0) {
+        UTrieHeader *outTrie;
+
+        if(length<size) {
+            *pErrorCode=U_INDEX_OUTOFBOUNDS_ERROR;
+            return 0;
+        }
+
+        outTrie=(UTrieHeader *)outData;
+
+        /* swap the header */
+        ds->swapArray32(ds, inTrie, sizeof(UTrieHeader), outTrie, pErrorCode);
+
+        /* swap the index and the data */
+        if(dataIs32) {
+            ds->swapArray16(ds, inTrie+1, trie.indexLength*2, outTrie+1, pErrorCode);
+            ds->swapArray32(ds, (const uint16_t *)(inTrie+1)+trie.indexLength, trie.dataLength*4,
+                                     (uint16_t *)(outTrie+1)+trie.indexLength, pErrorCode);
+        } else {
+            ds->swapArray16(ds, inTrie+1, (trie.indexLength+trie.dataLength)*2, outTrie+1, pErrorCode);
+        }
+    }
+
+    return size;
+}
+
 /* enumeration -------------------------------------------------------------- */
 
 /* default UTrieEnumValue() returns the input value itself */

icu4c/source/common/utrie.h

@@ -80,7 +80,7 @@ enum {
 
     /**
      * Number of index (stage 1) entries per lead surrogate.
-     * Same as number of indexe entries for 1024 trail surrogates,
+     * Same as number of index entries for 1024 trail surrogates,
      * ==0x400>>UTRIE_SHIFT
      */
     UTRIE_SURROGATE_BLOCK_COUNT=(1<<UTRIE_SURROGATE_BLOCK_BITS),
@@ -663,6 +663,19 @@ utrie_serialize(UNewTrie *trie, void *data, int32_t capacity,
                 UBool reduceTo16Bits,
                 UErrorCode *pErrorCode);
 
+/* forward declaration */
+struct UDataSwapper;
+typedef struct UDataSwapper UDataSwapper;
+
+/**
+ * Swap a serialized UTrie.
+ * @internal
+ */
+U_CAPI int32_t U_EXPORT2
+utrie_swap(const UDataSwapper *ds,
+           const void *inData, int32_t length, void *outData,
+           UErrorCode *pErrorCode);
+
 U_CDECL_END
 
 #endif