1 files changed, 398 insertions, 0 deletions
diff --git a/xpcom/io/nsUnicharInputStream.cpp b/xpcom/io/nsUnicharInputStream.cpp
new file mode 100644
index 000000000..27c074c09
--- /dev/null
+++ b/xpcom/io/nsUnicharInputStream.cpp
@@ -0,0 +1,398 @@
+/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
+/* vim: set ts=8 sts=2 et sw=2 tw=80: */
+/* 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/. */
+
+#include "nsUnicharInputStream.h"
+#include "nsIInputStream.h"
+#include "nsIServiceManager.h"
+#include "nsString.h"
+#include "nsTArray.h"
+#include "nsAutoPtr.h"
+#include "nsCRT.h"
+#include "nsStreamUtils.h"
+#include "nsUTF8Utils.h"
+#include "mozilla/Attributes.h"
+#include <fcntl.h>
+#if defined(XP_WIN)
+#include <io.h>
+#else
+#include <unistd.h>
+#endif
+
+#define STRING_BUFFER_SIZE 8192
+
+class StringUnicharInputStream final : public nsIUnicharInputStream
+{
+public:
+  explicit StringUnicharInputStream(const nsAString& aString) :
+    mString(aString), mPos(0), mLen(aString.Length()) { }
+
+  NS_DECL_ISUPPORTS
+  NS_DECL_NSIUNICHARINPUTSTREAM
+
+  nsString mString;
+  uint32_t mPos;
+  uint32_t mLen;
+
+private:
+  ~StringUnicharInputStream() { }
+};
+
+NS_IMETHODIMP
+StringUnicharInputStream::Read(char16_t* aBuf,
+                               uint32_t aCount,
+                               uint32_t* aReadCount)
+{
+  if (mPos >= mLen) {
+    *aReadCount = 0;
+    return NS_OK;
+  }
+  nsAString::const_iterator iter;
+  mString.BeginReading(iter);
+  const char16_t* us = iter.get();
+  uint32_t amount = mLen - mPos;
+  if (amount > aCount) {
+    amount = aCount;
+  }
+  memcpy(aBuf, us + mPos, sizeof(char16_t) * amount);
+  mPos += amount;
+  *aReadCount = amount;
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+StringUnicharInputStream::ReadSegments(nsWriteUnicharSegmentFun aWriter,
+                                       void* aClosure,
+                                       uint32_t aCount, uint32_t* aReadCount)
+{
+  uint32_t bytesWritten;
+  uint32_t totalBytesWritten = 0;
+
+  nsresult rv;
+  aCount = XPCOM_MIN(mString.Length() - mPos, aCount);
+
+  nsAString::const_iterator iter;
+  mString.BeginReading(iter);
+
+  while (aCount) {
+    rv = aWriter(this, aClosure, iter.get() + mPos,
+                 totalBytesWritten, aCount, &bytesWritten);
+
+    if (NS_FAILED(rv)) {
+      // don't propagate errors to the caller
+      break;
+    }
+
+    aCount -= bytesWritten;
+    totalBytesWritten += bytesWritten;
+    mPos += bytesWritten;
+  }
+
+  *aReadCount = totalBytesWritten;
+
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+StringUnicharInputStream::ReadString(uint32_t aCount, nsAString& aString,
+                                     uint32_t* aReadCount)
+{
+  if (mPos >= mLen) {
+    *aReadCount = 0;
+    return NS_OK;
+  }
+  uint32_t amount = mLen - mPos;
+  if (amount > aCount) {
+    amount = aCount;
+  }
+  aString = Substring(mString, mPos, amount);
+  mPos += amount;
+  *aReadCount = amount;
+  return NS_OK;
+}
+
+nsresult
+StringUnicharInputStream::Close()
+{
+  mPos = mLen;
+  return NS_OK;
+}
+
+NS_IMPL_ISUPPORTS(StringUnicharInputStream, nsIUnicharInputStream)
+
+//----------------------------------------------------------------------
+
+class UTF8InputStream final : public nsIUnicharInputStream
+{
+public:
+  UTF8InputStream();
+  nsresult Init(nsIInputStream* aStream);
+
+  NS_DECL_ISUPPORTS
+  NS_DECL_NSIUNICHARINPUTSTREAM
+
+private:
+  ~UTF8InputStream();
+
+protected:
+  int32_t Fill(nsresult* aErrorCode);
+
+  static void CountValidUTF8Bytes(const char* aBuf, uint32_t aMaxBytes,
+                                  uint32_t& aValidUTF8bytes,
+                                  uint32_t& aValidUTF16CodeUnits);
+
+  nsCOMPtr<nsIInputStream> mInput;
+  FallibleTArray<char> mByteData;
+  FallibleTArray<char16_t> mUnicharData;
+
+  uint32_t mByteDataOffset;
+  uint32_t mUnicharDataOffset;
+  uint32_t mUnicharDataLength;
+};
+
+UTF8InputStream::UTF8InputStream() :
+  mByteDataOffset(0),
+  mUnicharDataOffset(0),
+  mUnicharDataLength(0)
+{
+}
+
+nsresult
+UTF8InputStream::Init(nsIInputStream* aStream)
+{
+  if (!mByteData.SetCapacity(STRING_BUFFER_SIZE, mozilla::fallible) ||
+      !mUnicharData.SetCapacity(STRING_BUFFER_SIZE, mozilla::fallible)) {
+    return NS_ERROR_OUT_OF_MEMORY;
+  }
+  mInput = aStream;
+
+  return NS_OK;
+}
+
+NS_IMPL_ISUPPORTS(UTF8InputStream, nsIUnicharInputStream)
+
+UTF8InputStream::~UTF8InputStream()
+{
+  Close();
+}
+
+nsresult
+UTF8InputStream::Close()
+{
+  mInput = nullptr;
+  mByteData.Clear();
+  mUnicharData.Clear();
+  return NS_OK;
+}
+
+nsresult
+UTF8InputStream::Read(char16_t* aBuf, uint32_t aCount, uint32_t* aReadCount)
+{
+  NS_ASSERTION(mUnicharDataLength >= mUnicharDataOffset, "unsigned madness");
+  uint32_t readCount = mUnicharDataLength - mUnicharDataOffset;
+  nsresult errorCode;
+  if (0 == readCount) {
+    // Fill the unichar buffer
+    int32_t bytesRead = Fill(&errorCode);
+    if (bytesRead <= 0) {
+      *aReadCount = 0;
+      return errorCode;
+    }
+    readCount = bytesRead;
+  }
+  if (readCount > aCount) {
+    readCount = aCount;
+  }
+  memcpy(aBuf, mUnicharData.Elements() + mUnicharDataOffset,
+         readCount * sizeof(char16_t));
+  mUnicharDataOffset += readCount;
+  *aReadCount = readCount;
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+UTF8InputStream::ReadSegments(nsWriteUnicharSegmentFun aWriter,
+                              void* aClosure,
+                              uint32_t aCount, uint32_t* aReadCount)
+{
+  NS_ASSERTION(mUnicharDataLength >= mUnicharDataOffset, "unsigned madness");
+  uint32_t bytesToWrite = mUnicharDataLength - mUnicharDataOffset;
+  nsresult rv = NS_OK;
+  if (0 == bytesToWrite) {
+    // Fill the unichar buffer
+    int32_t bytesRead = Fill(&rv);
+    if (bytesRead <= 0) {
+      *aReadCount = 0;
+      return rv;
+    }
+    bytesToWrite = bytesRead;
+  }
+
+  if (bytesToWrite > aCount) {
+    bytesToWrite = aCount;
+  }
+
+  uint32_t bytesWritten;
+  uint32_t totalBytesWritten = 0;
+
+  while (bytesToWrite) {
+    rv = aWriter(this, aClosure,
+                 mUnicharData.Elements() + mUnicharDataOffset,
+                 totalBytesWritten, bytesToWrite, &bytesWritten);
+
+    if (NS_FAILED(rv)) {
+      // don't propagate errors to the caller
+      break;
+    }
+
+    bytesToWrite -= bytesWritten;
+    totalBytesWritten += bytesWritten;
+    mUnicharDataOffset += bytesWritten;
+  }
+
+  *aReadCount = totalBytesWritten;
+
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+UTF8InputStream::ReadString(uint32_t aCount, nsAString& aString,
+                            uint32_t* aReadCount)
+{
+  NS_ASSERTION(mUnicharDataLength >= mUnicharDataOffset, "unsigned madness");
+  uint32_t readCount = mUnicharDataLength - mUnicharDataOffset;
+  nsresult errorCode;
+  if (0 == readCount) {
+    // Fill the unichar buffer
+    int32_t bytesRead = Fill(&errorCode);
+    if (bytesRead <= 0) {
+      *aReadCount = 0;
+      return errorCode;
+    }
+    readCount = bytesRead;
+  }
+  if (readCount > aCount) {
+    readCount = aCount;
+  }
+  const char16_t* buf = mUnicharData.Elements() + mUnicharDataOffset;
+  aString.Assign(buf, readCount);
+
+  mUnicharDataOffset += readCount;
+  *aReadCount = readCount;
+  return NS_OK;
+}
+
+int32_t
+UTF8InputStream::Fill(nsresult* aErrorCode)
+{
+  if (!mInput) {
+    // We already closed the stream!
+    *aErrorCode = NS_BASE_STREAM_CLOSED;
+    return -1;
+  }
+
+  NS_ASSERTION(mByteData.Length() >= mByteDataOffset, "unsigned madness");
+  uint32_t remainder = mByteData.Length() - mByteDataOffset;
+  mByteDataOffset = remainder;
+  uint32_t nb;
+  *aErrorCode = NS_FillArray(mByteData, mInput, remainder, &nb);
+  if (nb == 0) {
+    // Because we assume a many to one conversion, the lingering data
+    // in the byte buffer must be a partial conversion
+    // fragment. Because we know that we have received no more new
+    // data to add to it, we can't convert it. Therefore, we discard
+    // it.
+    return nb;
+  }
+  NS_ASSERTION(remainder + nb == mByteData.Length(), "bad nb");
+
+  // Now convert as much of the byte buffer to unicode as possible
+  uint32_t srcLen, dstLen;
+  CountValidUTF8Bytes(mByteData.Elements(), remainder + nb, srcLen, dstLen);
+
+  // the number of UCS2 characters should always be <= the number of
+  // UTF8 chars
+  NS_ASSERTION(remainder + nb >= srcLen, "cannot be longer than out buffer");
+  NS_ASSERTION(dstLen <= mUnicharData.Capacity(),
+               "Ouch. I would overflow my buffer if I wasn't so careful.");
+  if (dstLen > mUnicharData.Capacity()) {
+    return 0;
+  }
+
+  ConvertUTF8toUTF16 converter(mUnicharData.Elements());
+
+  nsASingleFragmentCString::const_char_iterator start = mByteData.Elements();
+  nsASingleFragmentCString::const_char_iterator end = mByteData.Elements() + srcLen;
+
+  copy_string(start, end, converter);
+  if (converter.Length() != dstLen) {
+    *aErrorCode = NS_BASE_STREAM_BAD_CONVERSION;
+    return -1;
+  }
+
+  mUnicharDataOffset = 0;
+  mUnicharDataLength = dstLen;
+  mByteDataOffset = srcLen;
+
+  return dstLen;
+}
+
+void
+UTF8InputStream::CountValidUTF8Bytes(const char* aBuffer, uint32_t aMaxBytes,
+                                     uint32_t& aValidUTF8bytes,
+                                     uint32_t& aValidUTF16CodeUnits)
+{
+  const char* c = aBuffer;
+  const char* end = aBuffer + aMaxBytes;
+  const char* lastchar = c;  // pre-initialize in case of 0-length buffer
+  uint32_t utf16length = 0;
+  while (c < end && *c) {
+    lastchar = c;
+    utf16length++;
+
+    if (UTF8traits::isASCII(*c)) {
+      c++;
+    } else if (UTF8traits::is2byte(*c)) {
+      c += 2;
+    } else if (UTF8traits::is3byte(*c)) {
+      c += 3;
+    } else if (UTF8traits::is4byte(*c)) {
+      c += 4;
+      utf16length++; // add 1 more because this will be converted to a
+      // surrogate pair.
+    } else if (UTF8traits::is5byte(*c)) {
+      c += 5;
+    } else if (UTF8traits::is6byte(*c)) {
+      c += 6;
+    } else {
+      NS_WARNING("Unrecognized UTF8 string in UTF8InputStream::CountValidUTF8Bytes()");
+      break; // Otherwise we go into an infinite loop.  But what happens now?
+    }
+  }
+  if (c > end) {
+    c = lastchar;
+    utf16length--;
+  }
+
+  aValidUTF8bytes = c - aBuffer;
+  aValidUTF16CodeUnits = utf16length;
+}
+
+nsresult
+NS_NewUnicharInputStream(nsIInputStream* aStreamToWrap,
+                         nsIUnicharInputStream** aResult)
+{
+  *aResult = nullptr;
+
+  // Create converter input stream
+  RefPtr<UTF8InputStream> it = new UTF8InputStream();
+  nsresult rv = it->Init(aStreamToWrap);
+  if (NS_FAILED(rv)) {
+    return rv;
+  }
+
+  it.forget(aResult);
+  return NS_OK;
+}