Add new statement-based replication records to a MySQL binary log

decoded-table-map-event.txt

1b 7e 27 62 = Timestamp

13 = Type code

01 = Server ID

00 00 00 30 = Event Length

0000 00be = Next Position

0100 = Flags

---

00 00 6d = Table ID

00 00  = Reserved

00 00 00 01 00 = ??

03 = Length of DB Name
66 6f 6f 00 = 'foo'

03 = Length of Table Name
62 61 72 00 = 'bar'

02 = Number of Columns

03 = First Column Type (Long) (0 meta length)
0f = Second Column Type (Varchar) (2 bytes)

02 = Length of metadata

fc 03 = Second column metadata (1020 in hex)

03 = NULLable columns

62e1 6894 = CRC32

input-binlog.xxd

00000000: fe62 696e 84e6 1a62 0f01 0000 0077 0000  .bin...b.....w..
00000010: 007b 0000 0000 0004 0035 2e37 2e33 352d  .{.......5.7.35-
00000020: 3338 2d6c 6f67 0000 0000 0000 0000 0000  38-log..........
00000030: 0000 0000 0000 0000 0000 0000 0000 0000  ................
00000040: 0000 0000 0000 0000 0000 0000 0000 0013  ................
00000050: 380d 0008 0012 0004 0404 0412 0000 5f00  8............._.
00000060: 041a 0800 0000 0808 0802 0000 000a 0a0a  ................
00000070: 2a2a 0012 3400 010c 6eb7 2984 e61a 6223  **..4...n.)...b#
00000080: 0100 0000 1f00 0000 9a00 0000 8000 0000  ................
00000090: 0000 0000 0000 fc58 554c 84e6 1a62 2101  .......XUL...b!.
000000a0: 0000 0041 0000 00db 0000 0000 0001 e169  ...A...........i
000000b0: ac39 9776 11ec b8eb 0242 ac14 0002 0100  .9.v.....B......
000000c0: 0000 0000 0000 0200 0000 0000 0000 0001  ................
000000d0: 0000 0000 0000 00a3 387a 1084 e61a 6202  ........8z....b.
000000e0: 0100 0000 5b00 0000 3601 0000 0800 0200  ....[...6.......
000000f0: 0000 0000 0000 0300 0020 0000 0000 0000  ......... ......
00000100: 0120 00a0 5500 0000 0006 0373 7464 0421  . ..U......std.!
00000110: 0021 00e0 000c 0166 6f6f 0066 6f6f 0063  .!.....foo.foo.c
00000120: 7265 6174 6520 6461 7461 6261 7365 2066  reate database f
00000130: 6f6f af74 11ab 84e6 1a62 2101 0000 0041  oo.t.....b!....A
00000140: 0000 0077 0100 0000 0001 e169 ac39 9776  ...w.......i.9.v
00000150: 11ec b8eb 0242 ac14 0002 0200 0000 0000  .....B..........
00000160: 0000 0201 0000 0000 0000 0002 0000 0000  ................
00000170: 0000 0020 44cd ae84 e61a 6202 0100 0000  ... D.....b.....
00000180: 6200 0000 d901 0000 0000 0200 0000 0000  b...............
00000190: 0000 0000 0020 0000 0000 0000 0120 00a0  ..... ....... ..
000001a0: 5500 0000 0006 0373 7464 0421 0021 00e0  U......std.!.!..
000001b0: 000c 0166 6f6f 0000 6372 6561 7465 2074  ...foo..create t
000001c0: 6162 6c65 2066 6f6f 2e62 6172 2028 6964  able foo.bar (id
000001d0: 2069 6e74 2903 0025 9a84 e61a 6221 0100   int)..%....b!..
000001e0: 0000 4100 0000 1a02 0000 0000 01e1 69ac  ..A...........i.
000001f0: 3997 7611 ecb8 eb02 42ac 1400 0203 0000  9.v.....B.......
00000200: 0000 0000 0002 0200 0000 0000 0000 0300  ................
00000210: 0000 0000 0000 2dc3 5c1f 84e6 1a62 0201  ......-.\....b..
00000220: 0000 004a 0000 0064 0200 0008 0002 0000  ...J...d........
00000230: 0000 0000 0000 0000 2000 0000 0000 0001  ........ .......
00000240: 2000 a055 0000 0000 0603 7374 6404 2100   ..U......std.!.
00000250: 2100 e000 0c01 666f 6f00 0042 4547 494e  !.....foo..BEGIN
00000260: 9477 507b 84e6 1a62 0201 0000 0063 0000  .wP{...b.....c..
00000270: 00c7 0200 0000 0002 0000 0000 0000 0000  ................
00000280: 0000 2000 0000 0000 0001 2000 a055 0000  .. ....... ..U..
00000290: 0000 0603 7374 6404 2100 2100 e000 0c01  ....std.!.!.....
000002a0: 666f 6f00 0069 6e73 6572 7420 696e 746f  foo..insert into
000002b0: 2066 6f6f 2e62 6172 2076 616c 7565 7320   foo.bar values 
000002c0: 2831 2919 9648 0a84 e61a 6210 0100 0000  (1)..H....b.....
000002d0: 1f00 0000 e602 0000 0000 0d00 0000 0000  ................
000002e0: 0000 e660 e1e4 84e6 1a62 0401 0000 002f  ...`.....b...../
000002f0: 0000 0015 0300 0000 0004 0000 0000 0000  ................
00000300: 006d 7973 716c 2d62 696e 2e30 3030 3030  .mysql-bin.00000
00000310: 33f3 714d ab                             3.qM.

main.c

#include <stdio.h>
#include <unistd.h>
#include <string.h>
#include <stdlib.h>
#include <fcntl.h>

/* From https://stackoverflow.com/a/21001712 -- changed to not expect a NULL-terminated string */
unsigned int crc32b(unsigned char *message, int length) {
   int i, j;
   unsigned int byte, crc, mask;

   i = 0;
   crc = 0xFFFFFFFF;
   while (i < length) {
      byte = message[i];            // Get next byte.
      crc = crc ^ byte;
      for (j = 7; j >= 0; j--) {    // Do eight times.
         mask = -(crc & 1);
         crc = (crc >> 1) ^ (0xEDB88320 & mask);
      }
      i = i + 1;
   }
   return ~crc;
}

int main(int c, char** v) {
    char header[1000];
    char binlog_entry[1000];

    int in, out;

    in = open("mysql-bin.000002", O_RDONLY);
    read(in, header, 154);
    lseek(in, 612, SEEK_SET);
    bzero(binlog_entry, 1000);
    read(in, binlog_entry, 99);

    out = open("output", O_CREAT|O_WRONLY, 0666);
    write(out, header, 154);
    lseek(out, 612, SEEK_SET);
    write(out, binlog_entry, 99);


    char sql[] = "INSERT INTO real_table_that_exists VALUES ('real_data_that_exists_blah')";

    memcpy(binlog_entry + 65, sql, strlen(sql));


    long length = 65 + strlen(sql) + 4;


    long position = length + lseek(out, 0, SEEK_CUR);
    memcpy(binlog_entry + 13, &position, 4);

    memcpy(binlog_entry + 9, &length, 4);
    unsigned int crc = crc32b(binlog_entry, length - 4);
    
    memcpy(binlog_entry + length - 4, &crc, 4);

    write(out, binlog_entry, length);

    close(out);
    close(in);
}

Makefile

.PHONY: all
all: main
	./main
	mysqlbinlog --verify-binlog-checksum --start-position 711 output
main: main.c
	gcc main.c -o main

partially-decoded-rbr-event.txt

1b7e 2762 = Timestamp

1e = Type Code (v2 rows event)
01 = Server ID
0000 0038 = Event Length
0000 00f6 = Next Position
0100 = Flags
00 = ??
00 00 6d = Table ID
00 00 = Reserved (Row Level Flags)

00 00 00 01 == Extra Data Length ??
00 = ?? Extra Data

02 = Column Count
00 02 = Columns used (bitmap)
ff fc = Columns null
0200  .m..............
000001e0: 0000 0e00 7468 6973 2069 7320 6120 7465  ....this is a te
000001f0: 7374
d6c8 5307  = Checksum