mariadb/storage/archive/archive_reader.c
Davi Arnaut f56dd32bf7 Bug#34043: Server loops excessively in _checkchunk() when safemalloc is enabled
Essentially, the problem is that safemalloc is excruciatingly
slow as it checks all allocated blocks for overrun at each
memory management primitive, yielding a almost exponential
slowdown for the memory management functions (malloc, realloc,
free). The overrun check basically consists of verifying some
bytes of a block for certain magic keys, which catches some
simple forms of overrun. Another minor problem is violation
of aliasing rules and that its own internal list of blocks
is prone to corruption.

Another issue with safemalloc is rather the maintenance cost
as the tool has a significant impact on the server code.
Given the magnitude of memory debuggers available nowadays,
especially those that are provided with the platform malloc
implementation, maintenance of a in-house and largely obsolete
memory debugger becomes a burden that is not worth the effort
due to its slowness and lack of support for detecting more
common forms of heap corruption.

Since there are third-party tools that can provide the same
functionality at a lower or comparable performance cost, the
solution is to simply remove safemalloc. Third-party tools
can provide the same functionality at a lower or comparable
performance cost. 

The removal of safemalloc also allows a simplification of the
malloc wrappers, removing quite a bit of kludge: redefinition
of my_malloc, my_free and the removal of the unused second
argument of my_free. Since free() always check whether the
supplied pointer is null, redudant checks are also removed.

Also, this patch adds unit testing for my_malloc and moves
my_realloc implementation into the same file as the other
memory allocation primitives.

client/mysqldump.c:
  Pass my_free directly as its signature is compatible with the
  callback type -- which wasn't the case for free_table_ent.
2010-07-08 18:20:08 -03:00

405 lines
10 KiB
C

#include "azlib.h"
#include <string.h>
#include <assert.h>
#include <stdio.h>
#include <stdarg.h>
#include <m_ctype.h>
#include <m_string.h>
#include <my_getopt.h>
#include <mysql_version.h>
#define BUFFER_LEN 1024
#define ARCHIVE_ROW_HEADER_SIZE 4
#define SHOW_VERSION "0.1"
static void get_options(int *argc,char * * *argv);
static void print_version(void);
static void usage(void);
static const char *opt_tmpdir;
static const char *new_auto_increment;
unsigned long long new_auto_increment_value;
static const char *load_default_groups[]= { "archive_reader", 0 };
static char **default_argv;
int opt_check, opt_force, opt_quiet, opt_backup= 0, opt_extract_frm;
int opt_autoincrement;
int main(int argc, char *argv[])
{
unsigned int ret;
azio_stream reader_handle;
MY_INIT(argv[0]);
get_options(&argc, &argv);
if (argc < 1)
{
printf("No file specified. \n");
return 0;
}
if (!(ret= azopen(&reader_handle, argv[0], O_RDONLY|O_BINARY)))
{
printf("Could not open Archive file\n");
return 0;
}
if (opt_autoincrement)
{
azio_stream writer_handle;
if (new_auto_increment_value)
{
if (reader_handle.auto_increment >= new_auto_increment_value)
{
printf("Value is lower then current value\n");
goto end;
}
}
else
{
new_auto_increment_value= reader_handle.auto_increment + 1;
}
if (!(ret= azopen(&writer_handle, argv[0], O_CREAT|O_RDWR|O_BINARY)))
{
printf("Could not open file for update: %s\n", argv[0]);
goto end;
}
writer_handle.auto_increment= new_auto_increment_value;
azclose(&writer_handle);
azflush(&reader_handle, Z_SYNC_FLUSH);
}
printf("Version %u\n", reader_handle.version);
if (reader_handle.version > 2)
{
printf("\tMinor version %u\n", reader_handle.minor_version);
printf("\tStart position %llu\n", (unsigned long long)reader_handle.start);
printf("\tBlock size %u\n", reader_handle.block_size);
printf("\tRows %llu\n", reader_handle.rows);
printf("\tAutoincrement %llu\n", reader_handle.auto_increment);
printf("\tCheck Point %llu\n", reader_handle.check_point);
printf("\tForced Flushes %llu\n", reader_handle.forced_flushes);
printf("\tLongest Row %u\n", reader_handle.longest_row);
printf("\tShortest Row %u\n", reader_handle.shortest_row);
printf("\tState %s\n", ( reader_handle.dirty ? "dirty" : "clean"));
printf("\tFRM stored at %u\n", reader_handle.frm_start_pos);
printf("\tComment stored at %u\n", reader_handle.comment_start_pos);
printf("\tData starts at %u\n", (unsigned int)reader_handle.start);
if (reader_handle.frm_start_pos)
printf("\tFRM length %u\n", reader_handle.frm_length);
if (reader_handle.comment_start_pos)
{
char *comment =
(char *) malloc(sizeof(char) * reader_handle.comment_length);
azread_comment(&reader_handle, comment);
printf("\tComment length %u\n\t\t%.*s\n", reader_handle.comment_length,
reader_handle.comment_length, comment);
free(comment);
}
}
else
{
goto end;
}
printf("\n");
if (opt_check)
{
uchar size_buffer[ARCHIVE_ROW_HEADER_SIZE];
int error;
unsigned int x;
unsigned int read;
unsigned int row_len;
unsigned long long row_count= 0;
char buffer;
while ((read= azread(&reader_handle, (uchar *)size_buffer,
ARCHIVE_ROW_HEADER_SIZE, &error)))
{
if (error == Z_STREAM_ERROR || (read && read < ARCHIVE_ROW_HEADER_SIZE))
{
printf("Table is damaged\n");
goto end;
}
/* If we read nothing we are at the end of the file */
if (read == 0 || read != ARCHIVE_ROW_HEADER_SIZE)
break;
row_len= uint4korr(size_buffer);
row_count++;
if (row_len > reader_handle.longest_row)
{
printf("Table is damaged, row %llu is invalid\n",
row_count);
goto end;
}
for (read= x= 0; x < row_len ; x++)
{
read+= (unsigned int)azread(&reader_handle, &buffer, sizeof(char), &error);
if (!read)
break;
}
if (row_len != read)
{
printf("Row length did not match row (at %llu). %u != %u \n",
row_count, row_len, read);
goto end;
}
}
if (0)
{
printf("Table is damaged\n");
goto end;
}
else
{
printf("Found %llu rows\n", row_count);
}
}
if (opt_backup)
{
uchar size_buffer[ARCHIVE_ROW_HEADER_SIZE];
int error;
unsigned int read;
unsigned int row_len;
unsigned long long row_count= 0;
char *buffer;
azio_stream writer_handle;
buffer= (char *)malloc(reader_handle.longest_row);
if (buffer == NULL)
{
printf("Could not allocate memory for row %llu\n", row_count);
goto end;
}
if (!(ret= azopen(&writer_handle, argv[1], O_CREAT|O_RDWR|O_BINARY)))
{
printf("Could not open file for backup: %s\n", argv[1]);
goto end;
}
writer_handle.auto_increment= reader_handle.auto_increment;
if (reader_handle.frm_length)
{
char *ptr;
ptr= (char *)my_malloc(sizeof(char) * reader_handle.frm_length, MYF(0));
azread_frm(&reader_handle, ptr);
azwrite_frm(&writer_handle, ptr, reader_handle.frm_length);
my_free(ptr);
}
if (reader_handle.comment_length)
{
char *ptr;
ptr= (char *)my_malloc(sizeof(char) * reader_handle.comment_length, MYF(0));
azread_comment(&reader_handle, ptr);
azwrite_comment(&writer_handle, ptr, reader_handle.comment_length);
my_free(ptr);
}
while ((read= azread(&reader_handle, (uchar *)size_buffer,
ARCHIVE_ROW_HEADER_SIZE, &error)))
{
if (error == Z_STREAM_ERROR || (read && read < ARCHIVE_ROW_HEADER_SIZE))
{
printf("Table is damaged\n");
goto end;
}
/* If we read nothing we are at the end of the file */
if (read == 0 || read != ARCHIVE_ROW_HEADER_SIZE)
break;
row_len= uint4korr(size_buffer);
row_count++;
memcpy(buffer, size_buffer, ARCHIVE_ROW_HEADER_SIZE);
read= (unsigned int)azread(&reader_handle, buffer + ARCHIVE_ROW_HEADER_SIZE,
row_len, &error);
DBUG_ASSERT(read == row_len);
azwrite(&writer_handle, buffer, row_len + ARCHIVE_ROW_HEADER_SIZE);
if (row_len != read)
{
printf("Row length did not match row (at %llu). %u != %u \n",
row_count, row_len, read);
goto end;
}
if (reader_handle.rows == writer_handle.rows)
break;
}
free(buffer);
azclose(&writer_handle);
}
if (opt_extract_frm)
{
File frm_file;
char *ptr;
frm_file= my_open(argv[1], O_CREAT|O_RDWR|O_BINARY, MYF(0));
ptr= (char *)my_malloc(sizeof(char) * reader_handle.frm_length, MYF(0));
azread_frm(&reader_handle, ptr);
my_write(frm_file, (uchar*) ptr, reader_handle.frm_length, MYF(0));
my_close(frm_file, MYF(0));
my_free(ptr);
}
end:
printf("\n");
azclose(&reader_handle);
return 0;
}
static my_bool
get_one_option(int optid,
const struct my_option *opt __attribute__((unused)),
char *argument)
{
switch (optid) {
case 'b':
opt_backup= 1;
break;
case 'c':
opt_check= 1;
break;
case 'e':
opt_extract_frm= 1;
break;
case 'f':
opt_force= 1;
printf("Not implemented yet\n");
break;
case 'q':
opt_quiet= 1;
printf("Not implemented yet\n");
break;
case 'V':
print_version();
exit(0);
case 't':
printf("Not implemented yet\n");
break;
case 'A':
opt_autoincrement= 1;
if (argument)
new_auto_increment_value= strtoull(argument, NULL, 0);
else
new_auto_increment_value= 0;
break;
case '?':
usage();
exit(0);
case '#':
if (argument == disabled_my_option)
{
DBUG_POP();
}
else
{
DBUG_PUSH(argument ? argument : "d:t:o,/tmp/archive_reader.trace");
}
break;
}
return 0;
}
static struct my_option my_long_options[] =
{
{"backup", 'b',
"Make a backup of an archive table.",
0, 0, 0, GET_NO_ARG, NO_ARG, 0, 0, 0, 0, 0, 0},
{"check", 'c', "Check table for errors.",
0, 0, 0, GET_NO_ARG, NO_ARG, 0, 0, 0, 0, 0, 0},
#ifndef DBUG_OFF
{"debug", '#',
"Output debug log. Often this is 'd:t:o,filename'.",
0, 0, 0, GET_STR, OPT_ARG, 0, 0, 0, 0, 0, 0},
#endif
{"extract-frm", 'e',
"Extract the frm file.",
0, 0, 0, GET_NO_ARG, NO_ARG, 0, 0, 0, 0, 0, 0},
{"force", 'f',
"Restart with -r if there are any errors in the table.",
0, 0, 0, GET_NO_ARG, NO_ARG, 0, 0, 0, 0, 0, 0},
{"help", '?',
"Display this help and exit.",
0, 0, 0, GET_NO_ARG, NO_ARG, 0, 0, 0, 0, 0, 0},
{"quick", 'q', "Faster repair by not modifying the data file.",
0, 0, 0, GET_NO_ARG, NO_ARG, 0, 0, 0, 0, 0, 0},
{"repair", 'r', "Repair a damaged Archive version 3 or above file.",
0, 0, 0, GET_NO_ARG, NO_ARG, 0, 0, 0, 0, 0, 0},
{"set-auto-increment", 'A',
"Force auto_increment to start at this or higher value. If no value is given, then sets the next auto_increment value to the highest used value for the auto key + 1.",
&new_auto_increment, &new_auto_increment,
0, GET_ULL, OPT_ARG, 0, 0, 0, 0, 0, 0},
{"silent", 's',
"Only print errors. One can use two -s to make archive_reader very silent.",
0, 0, 0, GET_NO_ARG, NO_ARG, 0, 0, 0, 0, 0, 0},
{"tmpdir", 't',
"Path for temporary files.",
&opt_tmpdir,
0, 0, GET_STR, REQUIRED_ARG, 0, 0, 0, 0, 0, 0},
{"version", 'V',
"Print version and exit.",
0, 0, 0, GET_NO_ARG, NO_ARG, 0, 0, 0, 0, 0, 0},
{ 0, 0, 0, 0, 0, 0, GET_NO_ARG, NO_ARG, 0, 0, 0, 0, 0, 0}
};
static void usage(void)
{
print_version();
puts("Copyright 2007-2008 MySQL AB, 2008 Sun Microsystems, Inc.");
puts("This software comes with ABSOLUTELY NO WARRANTY. This is free software,\nand you are welcome to modify and redistribute it under the GPL license\n");
puts("Read and modify Archive files directly\n");
printf("Usage: %s [OPTIONS] file_to_be_looked_at [file_for_backup]\n", my_progname);
print_defaults("my", load_default_groups);
my_print_help(my_long_options);
}
static void print_version(void)
{
printf("%s Ver %s Distrib %s, for %s (%s)\n", my_progname, SHOW_VERSION,
MYSQL_SERVER_VERSION, SYSTEM_TYPE, MACHINE_TYPE);
}
static void get_options(int *argc, char ***argv)
{
if (load_defaults("my", load_default_groups, argc, argv))
exit(1);
default_argv= *argv;
handle_options(argc, argv, my_long_options, get_one_option);
if (*argc == 0)
{
usage();
exit(-1);
}
return;
} /* get options */