JavaScriptCore-1097.3.tar.gz

[apple/javascriptcore.git] / runtime / JSStringJoiner.cpp

diff --git a/runtime/JSStringJoiner.cpp b/runtime/JSStringJoiner.cpp
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+++ b/runtime/JSStringJoiner.cpp
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+/*
+ * Copyright (C) 2012 Apple Inc. All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in the
+ *    documentation and/or other materials provided with the distribution.
+ *
+ * THIS SOFTWARE IS PROVIDED BY APPLE INC. ``AS IS'' AND ANY
+ * EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
+ * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL APPLE INC. OR
+ * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
+ * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
+ * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
+ * PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY
+ * OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+ * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+ * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ */
+
+#include "config.h"
+#include "JSStringJoiner.h"
+
+#include "ExceptionHelpers.h"
+#include "JSString.h"
+#include "ScopeChain.h"
+#include <wtf/text/StringImpl.h>
+
+
+namespace JSC {
+
+// The destination is 16bits, at least one string is 16 bits.
+static inline void appendStringToData(UChar*& data, const UString& string)
+{
+    if (string.isNull())
+        return;
+
+    unsigned length = string.length();
+    const StringImpl* stringImpl = string.impl();
+
+    if (stringImpl->is8Bit()) {
+        for (unsigned i = 0; i < length; ++i) {
+            *data = stringImpl->characters8()[i];
+            ++data;
+        }
+    } else {
+        for (unsigned i = 0; i < length; ++i) {
+            *data = stringImpl->characters16()[i];
+            ++data;
+        }
+    }
+}
+
+// If the destination is 8bits, we know every string has to be 8bit.
+static inline void appendStringToData(LChar*& data, const UString& string)
+{
+    if (string.isNull())
+        return;
+    ASSERT(string.is8Bit());
+
+    unsigned length = string.length();
+    const StringImpl* stringImpl = string.impl();
+
+    for (unsigned i = 0; i < length; ++i) {
+        *data = stringImpl->characters8()[i];
+        ++data;
+    }
+}
+
+template<typename CharacterType>
+static inline PassRefPtr<StringImpl> joinStrings(const Vector<UString>& strings, const UString& separator, unsigned outputLength)
+{
+    ASSERT(outputLength);
+
+    CharacterType* data;
+    RefPtr<StringImpl> outputStringImpl = StringImpl::tryCreateUninitialized(outputLength, data);
+    if (!outputStringImpl)
+        return PassRefPtr<StringImpl>();
+
+    const UString firstString = strings.first();
+    appendStringToData(data, firstString);
+
+    for (size_t i = 1; i < strings.size(); ++i) {
+        appendStringToData(data, separator);
+        appendStringToData(data, strings[i]);
+    }
+
+    ASSERT(data == (outputStringImpl->getCharacters<CharacterType>() + outputStringImpl->length()));
+    return outputStringImpl.release();
+}
+
+JSValue JSStringJoiner::build(ExecState* exec)
+{
+    if (!m_isValid)
+        return throwOutOfMemoryError(exec);
+
+    if (!m_strings.size())
+        return jsEmptyString(exec);
+
+    size_t separatorLength = m_separator.length();
+    // FIXME: add special cases of joinStrings() for (separatorLength == 0) and (separatorLength == 1).
+    ASSERT(m_strings.size() > 0);
+    size_t totalSeparactorsLength = separatorLength * (m_strings.size() - 1);
+    size_t outputStringSize = totalSeparactorsLength + m_cumulatedStringsLength;
+
+    if (!outputStringSize)
+        return jsEmptyString(exec);
+
+    RefPtr<StringImpl> outputStringImpl;
+    if (m_is8Bits)
+        outputStringImpl = joinStrings<LChar>(m_strings, m_separator, outputStringSize);
+    else
+        outputStringImpl = joinStrings<UChar>(m_strings, m_separator, outputStringSize);
+
+    if (!outputStringImpl)
+        return throwOutOfMemoryError(exec);
+
+    return JSString::create(exec->globalData(), outputStringImpl.release());
+}
+
+}