1 files changed, 165 insertions, 0 deletions
diff --git a/intl/uconv/nsUnicodeToUTF8.cpp b/intl/uconv/nsUnicodeToUTF8.cpp
new file mode 100644
index 000000000..aff52d176
--- /dev/null
+++ b/intl/uconv/nsUnicodeToUTF8.cpp
@@ -0,0 +1,165 @@
+/* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+//----------------------------------------------------------------------
+// Global functions and data [declaration]
+#include "nsUnicodeToUTF8.h"
+#include "mozilla/CheckedInt.h"
+
+NS_IMPL_ISUPPORTS(nsUnicodeToUTF8, nsIUnicodeEncoder)
+
+//----------------------------------------------------------------------
+// nsUnicodeToUTF8 class [implementation]
+
+NS_IMETHODIMP nsUnicodeToUTF8::GetMaxLength(const char16_t* aSrc,
+                                            int32_t aSrcLength,
+                                            int32_t* aDestLength)
+{
+  MOZ_ASSERT(aDestLength);
+
+  // aSrc is interpreted as UTF16, 3 is normally enough.
+  // But when previous buffer only contains part of the surrogate pair, we
+  // need to complete it here. If the first word in following buffer is not
+  // in valid surrogate range, we need to convert the remaining of last buffer
+  // to 3 bytes.
+  mozilla::CheckedInt32 length = aSrcLength;
+  length *= 3;
+  length += 3;
+
+  if (!length.isValid()) {
+    return NS_ERROR_OUT_OF_MEMORY;
+  }
+
+  *aDestLength = length.value();
+  return NS_OK;
+}
+
+NS_IMETHODIMP nsUnicodeToUTF8::Convert(const char16_t* aSrc,
+                                       int32_t* aSrcLength,
+                                       char* aDest,
+                                       int32_t* aDestLength)
+{
+  const char16_t* src = aSrc;
+  const char16_t* srcEnd = aSrc + *aSrcLength;
+  char* dest = aDest;
+  int32_t destLen = *aDestLength;
+  uint32_t n;
+
+  //complete remaining of last conversion
+  if (mHighSurrogate) {
+    if (src < srcEnd) {
+      *aDestLength = 0;
+      return NS_OK_UENC_MOREINPUT;
+    }
+    if (*aDestLength < 4) {
+      *aSrcLength = 0;
+      *aDestLength = 0;
+      return NS_OK_UENC_MOREOUTPUT;
+    }
+    if (*src < (char16_t)0xdc00 || *src > (char16_t)0xdfff) { //not a pair
+      *dest++ = (char)0xef; //replacement character
+      *dest++ = (char)0xbf;
+      *dest++ = (char)0xbd;
+      destLen -= 3;
+    } else { 
+      n = ((mHighSurrogate - (char16_t)0xd800) << 10) + 
+              (*src - (char16_t)0xdc00) + 0x10000;
+      *dest++ = (char)0xf0 | (n >> 18);
+      *dest++ = (char)0x80 | ((n >> 12) & 0x3f);
+      *dest++ = (char)0x80 | ((n >> 6) & 0x3f);
+      *dest++ = (char)0x80 | (n & 0x3f);
+      ++src;
+      destLen -= 4;
+    }
+    mHighSurrogate = 0;
+  }
+
+  while (src < srcEnd) {
+    if ( *src <= 0x007f) {
+      if (destLen < 1)
+        goto error_more_output;
+      *dest++ = (char)*src;
+      --destLen;
+    } else if (*src <= 0x07ff) {
+      if (destLen < 2)
+        goto error_more_output;
+      *dest++ = (char)0xc0 | (*src >> 6);
+      *dest++ = (char)0x80 | (*src & 0x003f);
+      destLen -= 2;
+    } else if (*src >= (char16_t)0xd800 && *src <= (char16_t)0xdfff) {
+      if (*src >= (char16_t)0xdc00) { //not a pair
+        if (destLen < 3)
+          goto error_more_output;
+        *dest++ = (char)0xef; //replacement character
+        *dest++ = (char)0xbf;
+        *dest++ = (char)0xbd;
+        destLen -= 3;
+        ++src;
+        continue;
+      }
+      if ((src+1) >= srcEnd) {
+        //we need another surrogate to complete this unicode char
+        mHighSurrogate = *src;
+        *aDestLength = dest - aDest;
+        return NS_OK_UENC_MOREINPUT;
+      }
+      //handle surrogate
+      if (destLen < 4)
+        goto error_more_output;
+      if (*(src+1) < (char16_t)0xdc00 || *(src+1) > 0xdfff) { //not a pair
+        *dest++ = (char)0xef; //replacement character
+        *dest++ = (char)0xbf;
+        *dest++ = (char)0xbd;
+        destLen -= 3;
+      } else {
+        n = ((*src - (char16_t)0xd800) << 10) + (*(src+1) - (char16_t)0xdc00) + (uint32_t)0x10000;
+        *dest++ = (char)0xf0 | (n >> 18);
+        *dest++ = (char)0x80 | ((n >> 12) & 0x3f);
+        *dest++ = (char)0x80 | ((n >> 6) & 0x3f);
+        *dest++ = (char)0x80 | (n & 0x3f);
+        destLen -= 4;
+        ++src;
+      }
+    } else { 
+      if (destLen < 3)
+        goto error_more_output;
+      //treat rest of the character as BMP
+      *dest++ = (char)0xe0 | (*src >> 12);
+      *dest++ = (char)0x80 | ((*src >> 6) & 0x003f);
+      *dest++ = (char)0x80 | (*src & 0x003f);
+      destLen -= 3;
+    }
+    ++src;
+  }
+
+  *aDestLength = dest - aDest;
+  return NS_OK;
+
+error_more_output:
+  *aSrcLength = src - aSrc;
+  *aDestLength = dest - aDest;
+  return NS_OK_UENC_MOREOUTPUT;
+}
+
+NS_IMETHODIMP nsUnicodeToUTF8::Finish(char * aDest, int32_t * aDestLength)
+{
+  char * dest = aDest;
+
+  if (mHighSurrogate) {
+    if (*aDestLength < 3) {
+      *aDestLength = 0;
+      return NS_OK_UENC_MOREOUTPUT;
+    }
+    *dest++ = (char)0xef; //replacement character
+    *dest++ = (char)0xbf;
+    *dest++ = (char)0xbd;
+    mHighSurrogate = 0;
+    *aDestLength = 3;
+    return NS_OK;
+  } 
+
+  *aDestLength  = 0;
+  return NS_OK;
+}