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#ifndef BINLOG_ENCODE_H_INCLUDED
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#define BINLOG_ENCODE_H_INCLUDED
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/* -*- mode: c++; c-basic-offset: 2; indent-tabs-mode: nil; -*-
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* vim:expandtab:shiftwidth=2:tabstop=2:smarttab:
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* Copyright (C) 2008 Sun Microsystems
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* This program is free software; you can redistribute it and/or modify
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* it under the terms of the GNU General Public License as published by
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* the Free Software Foundation; version 2 of the License.
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* This program is distributed in the hope that it will be useful,
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* but WITHOUT ANY WARRANTY; without even the implied warranty of
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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* GNU General Public License for more details.
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* You should have received a copy of the GNU General Public License
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* along with this program; if not, write to the Free Software
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* Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
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#ifndef DRIZZLED_SERIALIZE_BINLOG_ENCODING_H
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#define DRIZZLED_SERIALIZE_BINLOG_ENCODING_H
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#define LENGTH_ENCODE_MAX_BYTES (sizeof(size_t) + 1)
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#define LENGTH_ENCODE_MAX_BYTES (sizeof(std::size_t) + 1)
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inline unsigned char *
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length_encode(size_t length, unsigned char *buf)
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length_encode(std::size_t length, unsigned char *buf)
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unsigned char *ptr= buf;
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assert(length > 1);
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*ptr++= length & 0xFF;
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*ptr++= (unsigned char) (length & 0xFF);
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int_fast8_t log2m1= -1; // ceil(log2(ptr - buf)) - 1
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uint_fast8_t pow2= 1; // pow2(log2m1 + 1)
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// Write the least significant byte of the current
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// length. Prefix increment is used to make space for the first
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// byte that will hold log2m1.
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*++ptr= length & 0xFF;
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*++ptr= (unsigned char)length & 0xFF;
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// Ensure the invariant holds by correcting it if it doesn't,
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// Clear the remaining bytes up to the next power of two
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memset(ptr + 1, 0, pow2 - (ptr - buf));
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std::memset(ptr + 1, 0, pow2 - (ptr - buf));
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ptr= buf + pow2 + 1;
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inline unsigned char *
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length_decode(unsigned char *buf, size_t *plen)
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length_decode(unsigned char *buf, std::size_t *plen)
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size_t bytes= 1 << (*buf + 1);
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std::size_t bytes= 1 << (*buf + 1);
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unsigned char *ptr= buf + 1;
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std::size_t length= 0;
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for (unsigned int i = 0 ; i < bytes ; ++i)
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length |= *ptr++ << (8 * i);