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97 lines
2.8 KiB
C++
97 lines
2.8 KiB
C++
/* Copyright (c) 2000, 2010, Oracle and/or its affiliates. All rights reserved.
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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 02110-1335 USA */
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/**
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@file
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@details
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Caching of files with only does (sequential) read or writes of fixed-
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length records. A read isn't allowed to go over file-length. A read is ok
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if it ends at file-length and next read can try to read after file-length
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(and get a EOF-error).
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Possibly use of asyncronic io.
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macros for read and writes for faster io.
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Used instead of FILE when reading or writing whole files.
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This will make mf_rec_cache obsolete.
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One can change info->pos_in_file to a higher value to skip bytes in file if
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also info->read_pos is set to info->read_end.
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If called through open_cached_file(), then the temporary file will
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only be created if a write exceeds the file buffer or if one calls
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flush_io_cache().
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*/
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#include "mariadb.h"
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#include "sql_priv.h"
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#include "sql_class.h" // THD
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#ifdef HAVE_REPLICATION
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extern "C" {
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/**
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Read buffered from the net.
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@retval
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1 if can't read requested characters
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@retval
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0 if record read
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*/
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int _my_b_net_read(IO_CACHE *info, uchar *Buffer, size_t)
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{
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ulong read_length;
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NET *net= &(current_thd)->net;
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DBUG_ENTER("_my_b_net_read");
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if (!info->end_of_file)
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DBUG_RETURN(1); /* because my_b_get (no _) takes 1 byte at a time */
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read_length= my_net_read_packet(net, 0);
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if (unlikely(read_length == packet_error))
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{
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info->error= -1;
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DBUG_RETURN(1);
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}
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if (unlikely(read_length == 0))
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{
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info->end_of_file= 0; /* End of file from client */
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DBUG_RETURN(1);
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}
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/* to set up stuff for my_b_get (no _) */
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info->read_end = (info->read_pos = (uchar*) net->read_pos) + read_length;
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Buffer[0] = info->read_pos[0]; /* length is always 1 */
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/*
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info->request_pos is used by log_loaded_block() to know the size
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of the current block.
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info->pos_in_file is used by log_loaded_block() too.
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*/
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info->pos_in_file+= read_length;
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info->request_pos=info->read_pos;
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info->read_pos++;
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DBUG_RETURN(0);
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}
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} /* extern "C" */
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#elif defined(_WIN32)
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// Remove linker warning 4221 about empty file
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namespace { char dummy; };
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#endif /* HAVE_REPLICATION */
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