New file for buffer management for shared strings, written by scc. Not yet added to the build. r=vidur

string/public/nsBufferHandleUtils.h

@@ -0,0 +1,106 @@
+/* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
+/*
+ * The contents of this file are subject to the Mozilla Public
+ * License Version 1.1 (the "License"); you may not use this file
+ * except in compliance with the License. You may obtain a copy of
+ * the License at http://www.mozilla.org/MPL/
+ * 
+ * Software distributed under the License is distributed on an "AS
+ * IS" basis, WITHOUT WARRANTY OF ANY KIND, either express or
+ * implied. See the License for the specific language governing
+ * rights and limitations under the License.
+ * 
+ * The Original Code is Mozilla strings.
+ * 
+ * The Initial Developer of the Original Code is Netscape
+ * Communications Corporation.  Portions created by Netscape are
+ * Copyright (C) 2000 Netscape Communications Corporation. All
+ * Rights Reserved.
+ *
+ * Contributor(s):
+ *   Scott Collins <scc@mozilla.org> (original author)
+ *
+ */
+
+#ifndef nsBufferHandleUtils_h___
+#define nsBufferHandleUtils_h___
+
+#ifndef nsAReadableString_h___
+#include "nsAReadableString.h"
+  // for |basic_nsAReadableString|...
+#endif
+
+#include <new.h>
+  // for placement |new|
+
+
+
+template <class HandleT, class CharT>
+inline
+size_t
+NS_AlignedHandleSize( const HandleT*, const CharT* )
+  {
+      // figure out the number of bytes needed the |HandleT| part, including padding to correctly align the data part
+    return ((sizeof(HandleT) + sizeof(CharT) - 1) / sizeof(CharT)) * sizeof(CharT);
+  }
+
+template <class HandleT, class CharT>
+inline
+const CharT*
+NS_DataAfterHandle( const HandleT* aHandlePtr, const CharT* aDummyCharTPtr )
+  {
+    typedef const CharT* CharT_ptr;
+    return CharT_ptr(NS_STATIC_CAST(const unsigned char*, aHandlePtr) + NS_AlignedHandleSize(aHandlePtr, aDummyCharTPtr));
+  }
+
+template <class HandleT, class CharT>
+inline
+CharT*
+NS_DataAfterHandle( HandleT* aHandlePtr, const CharT* aDummyCharTPtr )
+  {
+    typedef CharT* CharT_ptr;
+    return CharT_ptr(NS_STATIC_CAST(unsigned char*, aHandlePtr) + NS_AlignedHandleSize(aHandlePtr, aDummyCharTPtr));
+  }
+
+template <class HandleT, class CharT>
+HandleT*
+NS_AllocateContiguousHandleWithData( const HandleT* aDummyHandlePtr, const basic_nsAReadableString<CharT>& aDataSource, PRUint32 aAdditionalCapacity=1 )
+  {
+    typedef const CharT* CharT_ptr;
+
+      // figure out the number of bytes needed the |HandleT| part, including padding to correctly align the data part
+    size_t handle_size    = NS_AlignedHandleSize(aDummyHandlePtr, CharT_ptr(0));
+
+      // figure out how many |CharT|s wee need to fit in the data part
+    size_t data_length    = aDataSource.Length();
+    size_t buffer_length  = data_length + aAdditionalCapacity;
+
+      // how many bytes is that (including a zero-terminator so we can claim to be flat)?
+    size_t buffer_size    = buffer_length * sizeof(CharT);
+
+
+    HandleT* result = 0;
+    void* handle_ptr = ::operator new(handle_size + buffer_size);
+
+    if ( handle_ptr )
+      {
+        typedef CharT* CharT_ptr;
+        CharT* data_start_ptr = CharT_ptr(NS_STATIC_CAST(unsigned char*, handle_ptr) + handle_size);
+        CharT* data_end_ptr   = data_start_ptr + data_length;
+        CharT* buffer_end_ptr = data_start_ptr + buffer_length;
+
+        nsReadingIterator<CharT> fromBegin, fromEnd;
+        CharT* toBegin = data_start_ptr;
+        copy_string(aDataSource.BeginReading(fromBegin), aDataSource.EndReading(fromEnd), toBegin);
+
+          // and if the caller bothered asking for a buffer bigger than their string, we'll zero-terminate
+        if ( aAdditionalCapacity > 0 )
+          *toBegin = CharT(0);
+
+        result = new (handle_ptr) HandleT(data_start_ptr, data_end_ptr, data_start_ptr, buffer_end_ptr, PR_TRUE);
+      }
+
+    return result;
+  }
+
+#endif // !defined(nsBufferHandleUtils_h___)

xpcom/ds/nsBufferHandleUtils.h

@@ -0,0 +1,106 @@
+/* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
+/*
+ * The contents of this file are subject to the Mozilla Public
+ * License Version 1.1 (the "License"); you may not use this file
+ * except in compliance with the License. You may obtain a copy of
+ * the License at http://www.mozilla.org/MPL/
+ * 
+ * Software distributed under the License is distributed on an "AS
+ * IS" basis, WITHOUT WARRANTY OF ANY KIND, either express or
+ * implied. See the License for the specific language governing
+ * rights and limitations under the License.
+ * 
+ * The Original Code is Mozilla strings.
+ * 
+ * The Initial Developer of the Original Code is Netscape
+ * Communications Corporation.  Portions created by Netscape are
+ * Copyright (C) 2000 Netscape Communications Corporation. All
+ * Rights Reserved.
+ *
+ * Contributor(s):
+ *   Scott Collins <scc@mozilla.org> (original author)
+ *
+ */
+
+#ifndef nsBufferHandleUtils_h___
+#define nsBufferHandleUtils_h___
+
+#ifndef nsAReadableString_h___
+#include "nsAReadableString.h"
+  // for |basic_nsAReadableString|...
+#endif
+
+#include <new.h>
+  // for placement |new|
+
+
+
+template <class HandleT, class CharT>
+inline
+size_t
+NS_AlignedHandleSize( const HandleT*, const CharT* )
+  {
+      // figure out the number of bytes needed the |HandleT| part, including padding to correctly align the data part
+    return ((sizeof(HandleT) + sizeof(CharT) - 1) / sizeof(CharT)) * sizeof(CharT);
+  }
+
+template <class HandleT, class CharT>
+inline
+const CharT*
+NS_DataAfterHandle( const HandleT* aHandlePtr, const CharT* aDummyCharTPtr )
+  {
+    typedef const CharT* CharT_ptr;
+    return CharT_ptr(NS_STATIC_CAST(const unsigned char*, aHandlePtr) + NS_AlignedHandleSize(aHandlePtr, aDummyCharTPtr));
+  }
+
+template <class HandleT, class CharT>
+inline
+CharT*
+NS_DataAfterHandle( HandleT* aHandlePtr, const CharT* aDummyCharTPtr )
+  {
+    typedef CharT* CharT_ptr;
+    return CharT_ptr(NS_STATIC_CAST(unsigned char*, aHandlePtr) + NS_AlignedHandleSize(aHandlePtr, aDummyCharTPtr));
+  }
+
+template <class HandleT, class CharT>
+HandleT*
+NS_AllocateContiguousHandleWithData( const HandleT* aDummyHandlePtr, const basic_nsAReadableString<CharT>& aDataSource, PRUint32 aAdditionalCapacity=1 )
+  {
+    typedef const CharT* CharT_ptr;
+
+      // figure out the number of bytes needed the |HandleT| part, including padding to correctly align the data part
+    size_t handle_size    = NS_AlignedHandleSize(aDummyHandlePtr, CharT_ptr(0));
+
+      // figure out how many |CharT|s wee need to fit in the data part
+    size_t data_length    = aDataSource.Length();
+    size_t buffer_length  = data_length + aAdditionalCapacity;
+
+      // how many bytes is that (including a zero-terminator so we can claim to be flat)?
+    size_t buffer_size    = buffer_length * sizeof(CharT);
+
+
+    HandleT* result = 0;
+    void* handle_ptr = ::operator new(handle_size + buffer_size);
+
+    if ( handle_ptr )
+      {
+        typedef CharT* CharT_ptr;
+        CharT* data_start_ptr = CharT_ptr(NS_STATIC_CAST(unsigned char*, handle_ptr) + handle_size);
+        CharT* data_end_ptr   = data_start_ptr + data_length;
+        CharT* buffer_end_ptr = data_start_ptr + buffer_length;
+
+        nsReadingIterator<CharT> fromBegin, fromEnd;
+        CharT* toBegin = data_start_ptr;
+        copy_string(aDataSource.BeginReading(fromBegin), aDataSource.EndReading(fromEnd), toBegin);
+
+          // and if the caller bothered asking for a buffer bigger than their string, we'll zero-terminate
+        if ( aAdditionalCapacity > 0 )
+          *toBegin = CharT(0);
+
+        result = new (handle_ptr) HandleT(data_start_ptr, data_end_ptr, data_start_ptr, buffer_end_ptr, PR_TRUE);
+      }
+
+    return result;
+  }
+
+#endif // !defined(nsBufferHandleUtils_h___)

xpcom/string/public/nsBufferHandleUtils.h

@@ -0,0 +1,106 @@
+/* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
+/*
+ * The contents of this file are subject to the Mozilla Public
+ * License Version 1.1 (the "License"); you may not use this file
+ * except in compliance with the License. You may obtain a copy of
+ * the License at http://www.mozilla.org/MPL/
+ * 
+ * Software distributed under the License is distributed on an "AS
+ * IS" basis, WITHOUT WARRANTY OF ANY KIND, either express or
+ * implied. See the License for the specific language governing
+ * rights and limitations under the License.
+ * 
+ * The Original Code is Mozilla strings.
+ * 
+ * The Initial Developer of the Original Code is Netscape
+ * Communications Corporation.  Portions created by Netscape are
+ * Copyright (C) 2000 Netscape Communications Corporation. All
+ * Rights Reserved.
+ *
+ * Contributor(s):
+ *   Scott Collins <scc@mozilla.org> (original author)
+ *
+ */
+
+#ifndef nsBufferHandleUtils_h___
+#define nsBufferHandleUtils_h___
+
+#ifndef nsAReadableString_h___
+#include "nsAReadableString.h"
+  // for |basic_nsAReadableString|...
+#endif
+
+#include <new.h>
+  // for placement |new|
+
+
+
+template <class HandleT, class CharT>
+inline
+size_t
+NS_AlignedHandleSize( const HandleT*, const CharT* )
+  {
+      // figure out the number of bytes needed the |HandleT| part, including padding to correctly align the data part
+    return ((sizeof(HandleT) + sizeof(CharT) - 1) / sizeof(CharT)) * sizeof(CharT);
+  }
+
+template <class HandleT, class CharT>
+inline
+const CharT*
+NS_DataAfterHandle( const HandleT* aHandlePtr, const CharT* aDummyCharTPtr )
+  {
+    typedef const CharT* CharT_ptr;
+    return CharT_ptr(NS_STATIC_CAST(const unsigned char*, aHandlePtr) + NS_AlignedHandleSize(aHandlePtr, aDummyCharTPtr));
+  }
+
+template <class HandleT, class CharT>
+inline
+CharT*
+NS_DataAfterHandle( HandleT* aHandlePtr, const CharT* aDummyCharTPtr )
+  {
+    typedef CharT* CharT_ptr;
+    return CharT_ptr(NS_STATIC_CAST(unsigned char*, aHandlePtr) + NS_AlignedHandleSize(aHandlePtr, aDummyCharTPtr));
+  }
+
+template <class HandleT, class CharT>
+HandleT*
+NS_AllocateContiguousHandleWithData( const HandleT* aDummyHandlePtr, const basic_nsAReadableString<CharT>& aDataSource, PRUint32 aAdditionalCapacity=1 )
+  {
+    typedef const CharT* CharT_ptr;
+
+      // figure out the number of bytes needed the |HandleT| part, including padding to correctly align the data part
+    size_t handle_size    = NS_AlignedHandleSize(aDummyHandlePtr, CharT_ptr(0));
+
+      // figure out how many |CharT|s wee need to fit in the data part
+    size_t data_length    = aDataSource.Length();
+    size_t buffer_length  = data_length + aAdditionalCapacity;
+
+      // how many bytes is that (including a zero-terminator so we can claim to be flat)?
+    size_t buffer_size    = buffer_length * sizeof(CharT);
+
+
+    HandleT* result = 0;
+    void* handle_ptr = ::operator new(handle_size + buffer_size);
+
+    if ( handle_ptr )
+      {
+        typedef CharT* CharT_ptr;
+        CharT* data_start_ptr = CharT_ptr(NS_STATIC_CAST(unsigned char*, handle_ptr) + handle_size);
+        CharT* data_end_ptr   = data_start_ptr + data_length;
+        CharT* buffer_end_ptr = data_start_ptr + buffer_length;
+
+        nsReadingIterator<CharT> fromBegin, fromEnd;
+        CharT* toBegin = data_start_ptr;
+        copy_string(aDataSource.BeginReading(fromBegin), aDataSource.EndReading(fromEnd), toBegin);
+
+          // and if the caller bothered asking for a buffer bigger than their string, we'll zero-terminate
+        if ( aAdditionalCapacity > 0 )
+          *toBegin = CharT(0);
+
+        result = new (handle_ptr) HandleT(data_start_ptr, data_end_ptr, data_start_ptr, buffer_end_ptr, PR_TRUE);
+      }
+
+    return result;
+  }
+
+#endif // !defined(nsBufferHandleUtils_h___)