1 files changed, 132 insertions, 0 deletions
diff --git a/xpcom/io/nsUnicharInputStream.cpp b/xpcom/io/nsUnicharInputStream.cpp
new file mode 100644
index 0000000000..1366ab1e34
--- /dev/null
+++ b/xpcom/io/nsUnicharInputStream.cpp
@@ -0,0 +1,132 @@
+/* -*- 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 "nsString.h"
+#include "nsTArray.h"
+#include "nsCRT.h"
+#include "nsStreamUtils.h"
+#include "nsConverterInputStream.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() = default;
+};
+
+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<uint32_t>(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)
+
+//----------------------------------------------------------------------
+
+nsresult NS_NewUnicharInputStream(nsIInputStream* aStreamToWrap,
+                                  nsIUnicharInputStream** aResult) {
+  *aResult = nullptr;
+
+  // Create converter input stream
+  RefPtr<nsConverterInputStream> it = new nsConverterInputStream();
+  nsresult rv = it->Init(aStreamToWrap, "UTF-8", STRING_BUFFER_SIZE,
+                         nsIConverterInputStream::ERRORS_ARE_FATAL);
+  if (NS_FAILED(rv)) {
+    return rv;
+  }
+
+  it.forget(aResult);
+  return NS_OK;
+}