1.1 --- /dev/null	Thu Jan 01 00:00:00 1970 +0000
     1.2 +++ b/src/CompactBuffer.h	Tue Jul 24 23:53:34 2012 -0700
     1.3 @@ -0,0 +1,100 @@
     1.4 +/* vim: set ts=4 sw=4 tw=99 et:
     1.5 + *
     1.6 + * Copyright (C) 2012 David Anderson
     1.7 + *
     1.8 + * This file is part of JITCraft.
     1.9 + *
    1.10 + * JITCraft is free software: you can redistribute it and/or modify it under
    1.11 + * the terms of the GNU General Public License as published by the Free
    1.12 + * Software Foundation, either version 3 of the License, or (at your option)
    1.13 + * any later version.
    1.14 + * 
    1.15 + * Foobar is distributed in the hope that it will be useful, but WITHOUT ANY
    1.16 + * WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS
    1.17 + * FOR A PARTICULAR PURPOSE. See the GNU General Public License for more details.
    1.18 + *
    1.19 + * You should have received a copy of the GNU General Public License along with
    1.20 + * JITCraft. If not, see http://www.gnu.org/licenses/.
    1.21 + */
    1.22 +#ifndef _include_jc_compact_buffer_h_
    1.23 +#define _include_jc_compact_buffer_h_
    1.24 +
    1.25 +#include "AllocatorPolicies.h"
    1.26 +#include "Utility.h"
    1.27 +#include "Vector.h"
    1.28 +
    1.29 +namespace ke {
    1.30 +
    1.31 +class CompactBufferReader
    1.32 +{
    1.33 +    const uint8 *pos_;
    1.34 +    const uint8 *end_;
    1.35 +
    1.36 +  public:
    1.37 +    CompactBufferReader(const uint8 *start, const uint8 *end)
    1.38 +      : pos_(start),
    1.39 +        end_(end)
    1.40 +    {
    1.41 +    }
    1.42 +
    1.43 +    uint8 readUint8() {
    1.44 +        assert(pos_ < end_);
    1.45 +        return *pos_++;
    1.46 +    }
    1.47 +
    1.48 +    uint32 readUint32() {
    1.49 +        uint32 value = 0;
    1.50 +        uint32 shift = 0;
    1.51 +
    1.52 +        uint8 byte;
    1.53 +        do {
    1.54 +            byte = readUint8();
    1.55 +            value |= (byte >> 1) << shift;
    1.56 +            shift += 7;
    1.57 +        } while (byte & 1);
    1.58 +
    1.59 +        assert(shift < 32);
    1.60 +        return value;
    1.61 +    }
    1.62 +
    1.63 +    bool done() const {
    1.64 +        return pos_ == end_;
    1.65 +    }
    1.66 +};
    1.67 +
    1.68 +class CompactBufferWriter
    1.69 +{
    1.70 +    Vector<uint8, ZoneAllocatorPolicy> buffer_;
    1.71 +    bool enoughMemory_;
    1.72 +
    1.73 +  public:
    1.74 +    CompactBufferWriter()
    1.75 +      : enoughMemory_(true)
    1.76 +    {
    1.77 +    }
    1.78 +
    1.79 +    void writeUint8(unsigned value) {
    1.80 +        enoughMemory_ &= buffer_.append(value);
    1.81 +    }
    1.82 +    void writeUint32(unsigned value) {
    1.83 +        do {
    1.84 +            writeUint8(((value & 0x7F) << 1) | (value > 0x7F));
    1.85 +            value >>= 7;
    1.86 +        } while (value);
    1.87 +    }
    1.88 +
    1.89 +    uint8 *buffer() const {
    1.90 +        return buffer_.buffer();
    1.91 +    }
    1.92 +    size_t length() const {
    1.93 +        return buffer_.length();
    1.94 +    }
    1.95 +
    1.96 +    bool oom() const {
    1.97 +        return !enoughMemory_;
    1.98 +    }
    1.99 +};
   1.100 +
   1.101 +}
   1.102 +
   1.103 +#endif // _include_jc_compact_buffer_h_