--- /dev/null
+// Copyright 2010, Google 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:
+//
+// * Redistributions of source code must retain the above copyright
+// notice, this list of conditions and the following disclaimer.
+// * 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.
+// * Neither the name of Google Inc. nor the names of its
+// contributors may be used to endorse or promote products derived from
+// this software without specific prior written permission.
+//
+// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+// "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 THE COPYRIGHT
+// OWNER 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 URLBuffer_h
+#define URLBuffer_h
+
+namespace WTF {
+
+// Base class for the canonicalizer output, this maintains a buffer and
+// supports simple resizing and append operations on it.
+//
+// It is VERY IMPORTANT that no virtual function calls be made on the common
+// code path. We only have two virtual function calls, the destructor and a
+// resize function that is called when the existing buffer is not big enough.
+// The derived class is then in charge of setting up our buffer which we will
+// manage.
+template<typename CHAR>
+class URLBuffer {
+public:
+ URLBuffer() : m_buffer(0), m_capacity(0), m_length(0) { }
+ virtual ~URLBuffer() { }
+
+ // Implemented to resize the buffer. This function should update the buffer
+ // pointer to point to the new buffer, and any old data up to |m_length| in
+ // the buffer must be copied over.
+ //
+ // The new size must be larger than m_capacity.
+ virtual void resize(int) = 0;
+
+ inline char at(int offset) const { return m_buffer[offset]; }
+ inline void set(int offset, CHAR ch)
+ {
+ // FIXME: Add ASSERT(offset < length());
+ m_buffer[offset] = ch;
+ }
+
+ // Returns the current capacity of the buffer. The length() is the number of
+ // characters that have been declared to be written, but the capacity() is
+ // the number that can be written without reallocation. If the caller must
+ // write many characters at once, it can make sure there is enough capacity,
+ // write the data, then use setLength() to declare the new length().
+ int capacity() const { return m_capacity; }
+ int length() const { return m_length; }
+
+ // The output will NOT be 0-terminated. Call length() to get the length.
+ const CHAR* data() const { return m_buffer; }
+ CHAR* data() { return m_buffer; }
+
+ // Shortens the URL to the new length. Used for "backing up" when processing
+ // relative paths. This can also be used if an external function writes a lot
+ // of data to the buffer (when using the "Raw" version below) beyond the end,
+ // to declare the new length.
+ void setLength(int length)
+ {
+ // FIXME: Add ASSERT(length < capacity());
+ m_length = length;
+ }
+
+ // This is the most performance critical function, since it is called for
+ // every character.
+ void append(CHAR ch)
+ {
+ // In VC2005, putting this common case first speeds up execution
+ // dramatically because this branch is predicted as taken.
+ if (m_length < m_capacity) {
+ m_buffer[m_length] = ch;
+ ++m_length;
+ return;
+ }
+
+ if (!grow(1))
+ return;
+
+ m_buffer[m_length] = ch;
+ ++m_length;
+ }
+
+ void append(const CHAR* str, int strLength)
+ {
+ if (m_length + strLength > m_capacity) {
+ if (!grow(m_length + strLength - m_capacity))
+ return;
+ }
+ for (int i = 0; i < strLength; i++)
+ m_buffer[m_length + i] = str[i];
+ m_length += strLength;
+ }
+
+protected:
+ // Returns true if the buffer could be resized, false on OOM.
+ bool grow(int minimumAdditionalCapacity)
+ {
+ static const int minimumCapacity = 16;
+ int newCapacity = m_capacity ? m_capacity : minimumCapacity;
+ do {
+ if (newCapacity >= (1 << 30)) // Prevent overflow below.
+ return false;
+ newCapacity *= 2;
+ } while (newCapacity < m_capacity + minimumAdditionalCapacity);
+ resize(newCapacity);
+ return true;
+ }
+
+ CHAR* m_buffer;
+ int m_capacity;
+ int m_length; // Used characters in the buffer.
+};
+
+} // namespace WTF
+
+#endif // URLBuffer_h
projects / apple / javascriptcore.git / blobdiff