dvander@70: /* vim: set ts=4 sw=4 tw=99 et:
dvander@70:  *
dvander@70:  * Copyright (C) 2012 David Anderson
dvander@70:  *
dvander@70:  * This file is part of JITCraft.
dvander@70:  *
dvander@70:  * JITCraft is free software: you can redistribute it and/or modify it under
dvander@70:  * the terms of the GNU General Public License as published by the Free
dvander@70:  * Software Foundation, either version 3 of the License, or (at your option)
dvander@70:  * any later version.
dvander@70:  * 
dvander@70:  * Foobar is distributed in the hope that it will be useful, but WITHOUT ANY
dvander@70:  * WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS
dvander@70:  * FOR A PARTICULAR PURPOSE. See the GNU General Public License for more details.
dvander@70:  *
dvander@70:  * You should have received a copy of the GNU General Public License along with
dvander@70:  * JITCraft. If not, see http://www.gnu.org/licenses/.
dvander@70:  */
dvander@70: #ifndef _include_jc_compact_buffer_h_
dvander@70: #define _include_jc_compact_buffer_h_
dvander@70: 
dvander@70: #include "AllocatorPolicies.h"
dvander@70: #include "Utility.h"
dvander@70: #include "Vector.h"
dvander@70: 
dvander@70: namespace ke {
dvander@70: 
dvander@70: class CompactBufferReader
dvander@70: {
dvander@70:     const uint8 *pos_;
dvander@70:     const uint8 *end_;
dvander@70: 
dvander@70:   public:
dvander@70:     CompactBufferReader(const uint8 *start, const uint8 *end)
dvander@70:       : pos_(start),
dvander@70:         end_(end)
dvander@70:     {
dvander@70:     }
dvander@70: 
dvander@70:     uint8 readUint8() {
dvander@70:         assert(pos_ < end_);
dvander@70:         return *pos_++;
dvander@70:     }
dvander@70: 
dvander@70:     uint32 readUint32() {
dvander@70:         uint32 value = 0;
dvander@70:         uint32 shift = 0;
dvander@70: 
dvander@70:         uint8 byte;
dvander@70:         do {
dvander@70:             byte = readUint8();
dvander@70:             value |= (byte >> 1) << shift;
dvander@70:             shift += 7;
dvander@70:         } while (byte & 1);
dvander@70: 
dvander@70:         assert(shift < 32);
dvander@70:         return value;
dvander@70:     }
dvander@70: 
dvander@70:     bool done() const {
dvander@70:         return pos_ == end_;
dvander@70:     }
dvander@70: };
dvander@70: 
dvander@70: class CompactBufferWriter
dvander@70: {
dvander@70:     Vector<uint8, ZoneAllocatorPolicy> buffer_;
dvander@70:     bool enoughMemory_;
dvander@70: 
dvander@70:   public:
dvander@70:     CompactBufferWriter()
dvander@70:       : enoughMemory_(true)
dvander@70:     {
dvander@70:     }
dvander@70: 
dvander@70:     void writeUint8(unsigned value) {
dvander@70:         enoughMemory_ &= buffer_.append(value);
dvander@70:     }
dvander@70:     void writeUint32(unsigned value) {
dvander@70:         do {
dvander@70:             writeUint8(((value & 0x7F) << 1) | (value > 0x7F));
dvander@70:             value >>= 7;
dvander@70:         } while (value);
dvander@70:     }
dvander@70: 
dvander@70:     uint8 *buffer() const {
dvander@70:         return buffer_.buffer();
dvander@70:     }
dvander@70:     size_t length() const {
dvander@70:         return buffer_.length();
dvander@70:     }
dvander@70: 
dvander@70:     bool oom() const {
dvander@70:         return !enoughMemory_;
dvander@70:     }
dvander@70: };
dvander@70: 
dvander@70: }
dvander@70: 
dvander@70: #endif // _include_jc_compact_buffer_h_