ICU-62107.0.1.tar.gz

[apple/icu.git] / icuSources / common / bytesinkutil.cpp

diff --git a/icuSources/common/bytesinkutil.cpp b/icuSources/common/bytesinkutil.cpp
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+// © 2017 and later: Unicode, Inc. and others.
+// License & terms of use: http://www.unicode.org/copyright.html
+
+// bytesinkutil.cpp
+// created: 2017sep14 Markus W. Scherer
+
+#include "unicode/utypes.h"
+#include "unicode/bytestream.h"
+#include "unicode/edits.h"
+#include "unicode/stringoptions.h"
+#include "unicode/utf8.h"
+#include "unicode/utf16.h"
+#include "bytesinkutil.h"
+#include "cmemory.h"
+#include "uassert.h"
+
+U_NAMESPACE_BEGIN
+
+UBool
+ByteSinkUtil::appendChange(int32_t length, const char16_t *s16, int32_t s16Length,
+                           ByteSink &sink, Edits *edits, UErrorCode &errorCode) {
+    if (U_FAILURE(errorCode)) { return FALSE; }
+    char scratch[200];
+    int32_t s8Length = 0;
+    for (int32_t i = 0; i < s16Length;) {
+        int32_t capacity;
+        int32_t desiredCapacity = s16Length - i;
+        if (desiredCapacity < (INT32_MAX / 3)) {
+            desiredCapacity *= 3;  // max 3 UTF-8 bytes per UTF-16 code unit
+        } else if (desiredCapacity < (INT32_MAX / 2)) {
+            desiredCapacity *= 2;
+        } else {
+            desiredCapacity = INT32_MAX;
+        }
+        char *buffer = sink.GetAppendBuffer(U8_MAX_LENGTH, desiredCapacity,
+                                            scratch, UPRV_LENGTHOF(scratch), &capacity);
+        capacity -= U8_MAX_LENGTH - 1;
+        int32_t j = 0;
+        for (; i < s16Length && j < capacity;) {
+            UChar32 c;
+            U16_NEXT_UNSAFE(s16, i, c);
+            U8_APPEND_UNSAFE(buffer, j, c);
+        }
+        if (j > (INT32_MAX - s8Length)) {
+            errorCode = U_INDEX_OUTOFBOUNDS_ERROR;
+            return FALSE;
+        }
+        sink.Append(buffer, j);
+        s8Length += j;
+    }
+    if (edits != nullptr) {
+        edits->addReplace(length, s8Length);
+    }
+    return TRUE;
+}
+
+UBool
+ByteSinkUtil::appendChange(const uint8_t *s, const uint8_t *limit,
+                           const char16_t *s16, int32_t s16Length,
+                           ByteSink &sink, Edits *edits, UErrorCode &errorCode) {
+    if (U_FAILURE(errorCode)) { return FALSE; }
+    if ((limit - s) > INT32_MAX) {
+        errorCode = U_INDEX_OUTOFBOUNDS_ERROR;
+        return FALSE;
+    }
+    return appendChange((int32_t)(limit - s), s16, s16Length, sink, edits, errorCode);
+}
+
+void
+ByteSinkUtil::appendCodePoint(int32_t length, UChar32 c, ByteSink &sink, Edits *edits) {
+    char s8[U8_MAX_LENGTH];
+    int32_t s8Length = 0;
+    U8_APPEND_UNSAFE(s8, s8Length, c);
+    if (edits != nullptr) {
+        edits->addReplace(length, s8Length);
+    }
+    sink.Append(s8, s8Length);
+}
+
+namespace {
+
+// See unicode/utf8.h U8_APPEND_UNSAFE().
+inline uint8_t getTwoByteLead(UChar32 c) { return (uint8_t)((c >> 6) | 0xc0); }
+inline uint8_t getTwoByteTrail(UChar32 c) { return (uint8_t)((c & 0x3f) | 0x80); }
+
+}  // namespace
+
+void
+ByteSinkUtil::appendTwoBytes(UChar32 c, ByteSink &sink) {
+    U_ASSERT(0x80 <= c && c <= 0x7ff);  // 2-byte UTF-8
+    char s8[2] = { (char)getTwoByteLead(c), (char)getTwoByteTrail(c) };
+    sink.Append(s8, 2);
+}
+
+void
+ByteSinkUtil::appendNonEmptyUnchanged(const uint8_t *s, int32_t length,
+                                      ByteSink &sink, uint32_t options, Edits *edits) {
+    U_ASSERT(length > 0);
+    if (edits != nullptr) {
+        edits->addUnchanged(length);
+    }
+    if ((options & U_OMIT_UNCHANGED_TEXT) == 0) {
+        sink.Append(reinterpret_cast<const char *>(s), length);
+    }
+}
+
+UBool
+ByteSinkUtil::appendUnchanged(const uint8_t *s, const uint8_t *limit,
+                              ByteSink &sink, uint32_t options, Edits *edits,
+                              UErrorCode &errorCode) {
+    if (U_FAILURE(errorCode)) { return FALSE; }
+    if ((limit - s) > INT32_MAX) {
+        errorCode = U_INDEX_OUTOFBOUNDS_ERROR;
+        return FALSE;
+    }
+    int32_t length = (int32_t)(limit - s);
+    if (length > 0) {
+        appendNonEmptyUnchanged(s, length, sink, options, edits);
+    }
+    return TRUE;
+}
+
+U_NAMESPACE_END