initial commit, 4.5 stable

thirdparty/icu4c/common/ucnv_cb.cpp

@@ -0,0 +1,261 @@
+// © 2016 and later: Unicode, Inc. and others.
+// License & terms of use: http://www.unicode.org/copyright.html
+/*
+**********************************************************************
+*   Copyright (C) 2000-2006, International Business Machines
+*   Corporation and others.  All Rights Reserved.
+**********************************************************************
+ *  ucnv_cb.c:
+ *  External APIs for the ICU's codeset conversion library
+ *  Helena Shih
+ *
+ * Modification History:
+ *
+ *   Date        Name        Description
+ *   7/28/2000   srl         Implementation
+ */
+
+/**
+ * @name Character Conversion C API
+ *
+ */
+
+#include "unicode/utypes.h"
+
+#if !UCONFIG_NO_CONVERSION
+
+#include "unicode/ucnv_cb.h"
+#include "ucnv_bld.h"
+#include "ucnv_cnv.h"
+#include "cmemory.h"
+
+/* need to update the offsets when the target moves. */
+/* Note: Recursion may occur in the cb functions, be sure to update the offsets correctly
+if you don't use ucnv_cbXXX functions.  Make sure you don't use the same callback within
+the same call stack if the complexity arises. */
+U_CAPI void  U_EXPORT2
+ucnv_cbFromUWriteBytes (UConverterFromUnicodeArgs *args,
+                       const char* source,
+                       int32_t length,
+                       int32_t offsetIndex,
+                       UErrorCode * err)
+{
+    if(U_FAILURE(*err)) {
+        return;
+    }
+
+    ucnv_fromUWriteBytes(
+        args->converter,
+        source, length,
+        &args->target, args->targetLimit,
+        &args->offsets, offsetIndex,
+        err);
+}
+
+U_CAPI void  U_EXPORT2
+ucnv_cbFromUWriteUChars(UConverterFromUnicodeArgs *args,
+                             const char16_t** source,
+                             const char16_t*  sourceLimit,
+                             int32_t offsetIndex,
+                             UErrorCode * err)
+{
+    /*
+    This is a fun one.  Recursion can occur - we're basically going to
+    just retry shoving data through the same converter. Note, if you got
+    here through some kind of invalid sequence, you maybe should emit a
+    reset sequence of some kind and/or call ucnv_reset().  Since this
+    IS an actual conversion, take care that you've changed the callback
+    or the data, or you'll get an infinite loop.
+
+    Please set the err value to something reasonable before calling
+    into this.
+    */
+
+    char *oldTarget;
+
+    if(U_FAILURE(*err))
+    {
+        return;
+    }
+
+    oldTarget = args->target;
+
+    ucnv_fromUnicode(args->converter,
+        &args->target,
+        args->targetLimit,
+        source,
+        sourceLimit,
+        nullptr, /* no offsets */
+        false, /* no flush */
+        err);
+
+    if(args->offsets)
+    {
+        while (args->target != oldTarget)  /* if it moved at all.. */
+        {
+            *(args->offsets)++ = offsetIndex;
+            oldTarget++;
+        }
+    }
+
+    /*
+    Note, if you did something like used a Stop subcallback, things would get interesting.
+    In fact, here's where we want to return the partially consumed in-source!
+    */
+    if(*err == U_BUFFER_OVERFLOW_ERROR)
+    /* && (*source < sourceLimit && args->target >= args->targetLimit)
+    -- S. Hrcek */
+    {
+        /* Overflowed the target.  Now, we'll write into the charErrorBuffer.
+        It's a fixed size. If we overflow it... Hmm */
+        char *newTarget;
+        const char *newTargetLimit;
+        UErrorCode err2 = U_ZERO_ERROR;
+
+        int8_t errBuffLen;
+
+        errBuffLen  = args->converter->charErrorBufferLength;
+
+        /* start the new target at the first free slot in the errbuff.. */
+        newTarget = (char *)(args->converter->charErrorBuffer + errBuffLen);
+
+        newTargetLimit = (char *)(args->converter->charErrorBuffer +
+            sizeof(args->converter->charErrorBuffer));
+
+        if(newTarget >= newTargetLimit)
+        {
+            *err = U_INTERNAL_PROGRAM_ERROR;
+            return;
+        }
+
+        /* We're going to tell the converter that the errbuff len is empty.
+        This prevents the existing errbuff from being 'flushed' out onto
+        itself.  If the errbuff is needed by the converter this time,
+        we're hosed - we're out of space! */
+
+        args->converter->charErrorBufferLength = 0;
+
+        ucnv_fromUnicode(args->converter,
+                         &newTarget,
+                         newTargetLimit,
+                         source,
+                         sourceLimit,
+                         nullptr,
+                         false,
+                         &err2);
+
+        /* We can go ahead and overwrite the  length here. We know just how
+        to recalculate it. */
+
+        args->converter->charErrorBufferLength = (int8_t)(
+            newTarget - (char*)args->converter->charErrorBuffer);
+
+        if((newTarget >= newTargetLimit) || (err2 == U_BUFFER_OVERFLOW_ERROR))
+        {
+            /* now we're REALLY in trouble.
+            Internal program error - callback shouldn't have written this much
+            data!
+            */
+            *err = U_INTERNAL_PROGRAM_ERROR;
+            return;
+        }
+        /*else {*/
+            /* sub errs could be invalid/truncated/illegal chars or w/e.
+            These might want to be passed on up.. But the problem is, we already
+            need to pass U_BUFFER_OVERFLOW_ERROR. That has to override these
+            other errs.. */
+
+            /*
+            if(U_FAILURE(err2))
+            ??
+            */
+        /*}*/
+    }
+}
+
+U_CAPI void  U_EXPORT2
+ucnv_cbFromUWriteSub (UConverterFromUnicodeArgs *args,
+                           int32_t offsetIndex,
+                           UErrorCode * err)
+{
+    UConverter *converter;
+    int32_t length;
+
+    if(U_FAILURE(*err)) {
+        return;
+    }
+    converter = args->converter;
+    length = converter->subCharLen;
+
+    if(length == 0) {
+        return;
+    }
+
+    if(length < 0) {
+        /*
+         * Write/convert the substitution string. Its real length is -length.
+         * Unlike the escape callback, we need not change the converter's
+         * callback function because ucnv_setSubstString() verified that
+         * the string can be converted, so we will not get a conversion error
+         * and will not recurse.
+         * At worst we should get a U_BUFFER_OVERFLOW_ERROR.
+         */
+        const char16_t *source = (const char16_t *)converter->subChars;
+        ucnv_cbFromUWriteUChars(args, &source, source - length, offsetIndex, err);
+        return;
+    }
+
+    if(converter->sharedData->impl->writeSub!=nullptr) {
+        converter->sharedData->impl->writeSub(args, offsetIndex, err);
+    }
+    else if(converter->subChar1!=0 && (uint16_t)converter->invalidUCharBuffer[0]<=(uint16_t)0xffu) {
+        /*
+        TODO: Is this untestable because the MBCS converter has a writeSub function to call
+        and the other converters don't use subChar1?
+        */
+        ucnv_cbFromUWriteBytes(args,
+                               (const char *)&converter->subChar1, 1,
+                               offsetIndex, err);
+    }
+    else {
+        ucnv_cbFromUWriteBytes(args,
+                               (const char *)converter->subChars, length,
+                               offsetIndex, err);
+    }
+}
+
+U_CAPI void  U_EXPORT2
+ucnv_cbToUWriteUChars (UConverterToUnicodeArgs *args,
+                            const char16_t* source,
+                            int32_t length,
+                            int32_t offsetIndex,
+                            UErrorCode * err)
+{
+    if(U_FAILURE(*err)) {
+        return;
+    }
+
+    ucnv_toUWriteUChars(
+        args->converter,
+        source, length,
+        &args->target, args->targetLimit,
+        &args->offsets, offsetIndex,
+        err);
+}
+
+U_CAPI void  U_EXPORT2
+ucnv_cbToUWriteSub (UConverterToUnicodeArgs *args,
+                         int32_t offsetIndex,
+                       UErrorCode * err)
+{
+    static const char16_t kSubstituteChar1 = 0x1A, kSubstituteChar = 0xFFFD;
+
+    /* could optimize this case, just one uchar */
+    if(args->converter->invalidCharLength == 1 && args->converter->subChar1 != 0) {
+        ucnv_cbToUWriteUChars(args, &kSubstituteChar1, 1, offsetIndex, err);
+    } else {
+        ucnv_cbToUWriteUChars(args, &kSubstituteChar, 1, offsetIndex, err);
+    }
+}
+
+#endif