介绍py_innodb_page_info工具

py_innodb_page_info工具为《INNODB存储引擎》作者姜承尧写的。
该工具用来分析表空间中的各页得类型和信息，用python编写。
由三个文件py_innodb_page_info.py,mylib.py和include.py组成。
在应用是需要放在同一个目录下，chmod 755 这三个文件的权限。

[root@oradba mysql]# ./py_innodb_page_info.py -h
Get InnoDB Page Info
Usage: python py_innodb_page_info.py [OPTIONS] tablespace_file

The following options may be given as the first argument:
-h        help
-o output put the result to file
-t number thread to anayle the tablespace file
-v        verbose mode //查看更详细的内容

=============
文件名:py_innodb_page_info.py
#! /usr/bin/env python
#encoding=utf-8
import mylib
from sys import argv
from mylib import myargv

if __name__ == '__main__':
    myargv = myargv(argv)
    if myargv.parse_cmdline() == 0:
        pass
    else:
        mylib.get_innodb_page_type(myargv)
       
===========
文件名：mylib.py
#encoding=utf-8
import os
import include
from include import *

TABLESPACE_NAME='D:\\mysql_data\\test\\t.ibd'
VARIABLE_FIELD_COUNT = 1
NULL_FIELD_COUNT = 0

class myargv(object):
    def __init__(self, argv):
        self.argv = argv
        self.parms = {}
        self.tablespace = ''
   
    def parse_cmdline(self):
        argv = self.argv
        if len(argv) == 1:
            print 'Usage: python py_innodb_page_info.py [OPTIONS] tablespace_file'
            print 'For more options, use python py_innodb_page_info.py -h'
            return 0
        while argv:
            if argv[0][0] == '-':
                if argv[0][1] == 'h':
                    self.parms[argv[0]] = ''
                    argv = argv[1:]
                    break
                if argv[0][1] == 'v':
                    self.parms[argv[0]] = ''
                    argv = argv[1:]           
                else:
                    self.parms[argv[0]] = argv[1]
                    argv = argv[2:]
            else:
                self.tablespace = argv[0]
                argv = argv[1:]
        if self.parms.has_key('-h'):
            print 'Get InnoDB Page Info'
            print 'Usage: python py_innodb_page_info.py [OPTIONS] tablespace_file\n'
            print 'The following options may be given as the first argument:'
            print '-h        help '
            print '-o output put the result to file'
            print '-t number thread to anayle the tablespace file'
            print '-v        verbose mode'
            return 0
        return 1
       
def mach_read_from_n(page,start_offset,length):
    ret = page[start_offset:start_offset+length]
    return ret.encode('hex')
   
def get_innodb_page_type(myargv):
    f=file(myargv.tablespace,'rb')
    fsize = os.path.getsize(f.name)/INNODB_PAGE_SIZE
    ret = {}
    for i in range(fsize):
        page = f.read(INNODB_PAGE_SIZE)
        page_offset = mach_read_from_n(page,FIL_PAGE_OFFSET,4)
        page_type = mach_read_from_n(page,FIL_PAGE_TYPE,2)
        if myargv.parms.has_key('-v'):
            if page_type == '45bf':
                page_level = mach_read_from_n(page,FIL_PAGE_DATA+PAGE_LEVEL,2)
                print "page offset %s, page type <%s>, page level <%s>"%(page_offset,innodb_page_type[page_type],page_level)
            else:
                print "page offset %s, page type <%s>"%(page_offset,innodb_page_type[page_type])
        if not ret.has_key(page_type):
            ret[page_type] = 1
        else:
            ret[page_type] = ret[page_type] + 1
    print "Total number of page: %d:"%fsize
    for type in ret:
        print "%s: %s"%(innodb_page_type[type],ret[type])
       


===========
文件名：include.py
#encoding=utf-8
INNODB_PAGE_SIZE = 16*1024*1024

# Start of the data on the page
FIL_PAGE_DATA = 38


FIL_PAGE_OFFSET = 4 # page offset inside space
FIL_PAGE_TYPE = 24 # File page type

# Types of an undo log segment */
TRX_UNDO_INSERT = 1
TRX_UNDO_UPDATE = 2

# On a page of any file segment, data may be put starting from this offset
FSEG_PAGE_DATA = FIL_PAGE_DATA

# The offset of the undo log page header on pages of the undo log
TRX_UNDO_PAGE_HDR = FSEG_PAGE_DATA

PAGE_LEVEL = 26    #level of the node in an index tree; the leaf level is the level 0 */
               
innodb_page_type={
    '0000':u'Freshly Allocated Page',
    '0002':u'Undo Log Page',
    '0003':u'File Segment inode',
    '0004':u'Insert Buffer Free List',
    '0005':u'Insert Buffer Bitmap',
    '0006':u'System Page',
    '0007':u'Transaction system Page',
    '0008':u'File Space Header',
    '0009':u'扩展描述页',
    '000a':u'Uncompressed BLOB Page',
    '000b':u'1st compressed BLOB Page',
    '000c':u'Subsequent compressed BLOB Page',
    '45bf':u'B-tree Node'
    }
   
innodb_page_direction={
    '0000': 'Unknown(0x0000)',
    '0001': 'Page Left',
    '0002': 'Page Right',
    '0003': 'Page Same Rec',
    '0004': 'Page Same Page',
    '0005': 'Page No Direction',
    'ffff': 'Unkown2(0xffff)'
}

INNODB_PAGE_SIZE=1024*16 # InnoDB Page 16K


===========