/* vim: set ts=4 sw=4 tw=99 et:

  *

  * Copyright (C) 2012 David Anderson

  *

  * This file is part of JITCraft.

  *

  * JITCraft is free software: you can redistribute it and/or modify it under

  * the terms of the GNU General Public License as published by the Free

  * Software Foundation, either version 3 of the License, or (at your option)

  * any later version.

  * 

  * Foobar is distributed in the hope that it will be useful, but WITHOUT ANY

  * WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS

  * FOR A PARTICULAR PURPOSE. See the GNU General Public License for more details.

  *

  * You should have received a copy of the GNU General Public License along with

  * JITCraft. If not, see http://www.gnu.org/licenses/.

  */

 #ifndef _include_jc_compact_buffer_h_

 #define _include_jc_compact_buffer_h_

 #include "AllocatorPolicies.h"

 #include "Utility.h"

 #include "Vector.h"

 namespace ke {

 class CompactBufferReader

 {

     const uint8 *pos_;

     const uint8 *end_;

   public:

     CompactBufferReader(const uint8 *start, const uint8 *end)

       : pos_(start),

         end_(end)

     {

     }

     uint8 readUint8() {

         assert(pos_ < end_);

         return *pos_++;

     }

     uint32 readUint32() {

         uint32 value = 0;

         uint32 shift = 0;

         uint8 byte;

         do {

             byte = readUint8();

             value |= (byte >> 1) << shift;

             shift += 7;

         } while (byte & 1);

         assert(shift < 32);

         return value;

     }

     bool done() const {

         return pos_ == end_;

     }

 };

 class CompactBufferWriter

 {

     Vector<uint8, ZoneAllocatorPolicy> buffer_;

     bool enoughMemory_;

   public:

     CompactBufferWriter()

       : enoughMemory_(true)

     {

     }

     void writeUint8(unsigned value) {

         enoughMemory_ &= buffer_.append(value);

     }

     void writeUint32(unsigned value) {

         do {

             writeUint8(((value & 0x7F) << 1) | (value > 0x7F));

             value >>= 7;

         } while (value);

     }

     uint8 *buffer() const {

         return buffer_.buffer();

     }

     size_t length() const {

         return buffer_.length();

     }

     bool oom() const {

         return !enoughMemory_;

     }

 };

 }

 #endif // _include_jc_compact_buffer_h_