CSE2410 Fall 2014 Bounce

// Copyright 2008 the V8 project authors. 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 V8_COMPILATION_CACHE_H_

#define V8_COMPILATION_CACHE_H_

namespace v8 { namespace internal {

// The compilation cache keeps function boilerplates for compiled

// scripts and evals. The boilerplates are looked up using the source

// string as the key.

class CompilationCache {

 public:

  // The same source code string has different compiled code for

  // scripts and evals. Internally, we use separate caches to avoid

  // getting the wrong kind of entry when looking up.

  enum Entry {

    SCRIPT,

    EVAL_GLOBAL,

    EVAL_CONTEXTUAL,

    REGEXP,

    LAST_ENTRY = REGEXP

  };

  // Finds the script function boilerplate for a source

  // string. Returns an empty handle if the cache doesn't contain a

  // script for the given source string with the right origin.

  static Handle<JSFunction> LookupScript(Handle<String> source,

                                         Handle<Object> name,

                                         int line_offset,

                                         int column_offset);

  // Finds the function boilerplate for a source string for eval in a

  // given context.  Returns an empty handle if the cache doesn't

  // contain a script for the given source string.

  static Handle<JSFunction> LookupEval(Handle<String> source,

                                       Handle<Context> context,

                                       Entry entry);

  // Returns the regexp data associated with the given regexp if it

  // is in cache, otherwise an empty handle.

  static Handle<FixedArray> LookupRegExp(Handle<String> source,

                                         JSRegExp::Flags flags);

  // Associate the (source, kind) pair to the boilerplate. This may

  // overwrite an existing mapping.

  static void PutScript(Handle<String> source,

                        Handle<JSFunction> boilerplate);

  // Associate the (source, context->closure()->shared(), kind) triple

  // with the boilerplate. This may overwrite an existing mapping.

  static void PutEval(Handle<String> source,

                      Handle<Context> context,

                      Entry entry,

                      Handle<JSFunction> boilerplate);

  // Associate the (source, flags) pair to the given regexp data.

  // This may overwrite an existing mapping.

  static void PutRegExp(Handle<String> source,

                        JSRegExp::Flags flags,

                        Handle<FixedArray> data);

  // Clear the cache - also used to initialize the cache at startup.

  static void Clear();

  // GC support.

  static void Iterate(ObjectVisitor* v);

  // Notify the cache that a mark-sweep garbage collection is about to

  // take place. This is used to retire entries from the cache to

  // avoid keeping them alive too long without using them. For now, we

  // just clear the cache but we should consider are more

  // sophisticated LRU scheme.

  static void MarkCompactPrologue() { Clear(); }

};

} }  // namespace v8::internal

#endif  // V8_COMPILATION_CACHE_H_