JavaScriptCore-903.tar.gz

[apple/javascriptcore.git] / wtf / text / StringBuilder.h

diff --git a/wtf/text/StringBuilder.h b/wtf/text/StringBuilder.h
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+/*
+ * Copyright (C) 2009, 2010 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. 
+ */
+
+#ifndef StringBuilder_h
+#define StringBuilder_h
+
+#include <wtf/Vector.h>
+#include <wtf/text/WTFString.h>
+
+namespace WTF {
+
+class StringBuilder {
+public:
+    StringBuilder()
+        : m_length(0)
+    {
+    }
+
+    void append(const UChar*, unsigned);
+    void append(const char*, unsigned);
+
+    void append(const String& string)
+    {
+        // If we're appending to an empty string, and there is not buffer
+        // (in case reserveCapacity has been called) then just retain the
+        // string.
+        if (!m_length && !m_buffer) {
+            m_string = string;
+            m_length = string.length();
+            return;
+        }
+        append(string.characters(), string.length());
+    }
+
+    void append(const char* characters)
+    {
+        if (characters)
+            append(characters, strlen(characters));
+    }
+
+    void append(UChar c)
+    {
+        if (m_buffer && m_length < m_buffer->length() && m_string.isNull())
+            m_bufferCharacters[m_length++] = c;
+        else
+            append(&c, 1);
+    }
+
+    void append(char c)
+    {
+        if (m_buffer && m_length < m_buffer->length() && m_string.isNull())
+            m_bufferCharacters[m_length++] = (unsigned char)c;
+        else
+            append(&c, 1);
+    }
+
+    String toString()
+    {
+        if (m_string.isNull()) {
+            shrinkToFit();
+            reifyString();
+        }
+        return m_string;
+    }
+
+    String toStringPreserveCapacity()
+    {
+        if (m_string.isNull())
+            reifyString();
+        return m_string;
+    }
+
+    unsigned length() const
+    {
+        return m_length;
+    }
+
+    bool isEmpty() const { return !length(); }
+
+    void reserveCapacity(unsigned newCapacity);
+
+    void resize(unsigned newSize);
+
+    void shrinkToFit();
+
+    UChar operator[](unsigned i) const
+    {
+        ASSERT(i < m_length);
+        if (!m_string.isNull())
+            return m_string[i];
+        ASSERT(m_buffer);
+        return m_buffer->characters()[i];
+    }
+
+    void clear()
+    {
+        m_length = 0;
+        m_string = String();
+        m_buffer = 0;
+    }
+
+private:
+    void allocateBuffer(const UChar* currentCharacters, unsigned requiredLength);
+    UChar* appendUninitialized(unsigned length);
+    void reifyString();
+
+    unsigned m_length;
+    String m_string;
+    RefPtr<StringImpl> m_buffer;
+    UChar* m_bufferCharacters;
+};
+
+} // namespace WTF
+
+using WTF::StringBuilder;
+
+#endif // StringBuilder_h