checksum

Python, checksum of a dict

我的梦境 提交于 2019-12-05 00:32:26
I'm thinking to create a checksum of a dict to know if it was modified or not For the moment i have that: >>> import hashlib >>> import pickle >>> d = {'k': 'v', 'k2': 'v2'} >>> z = pickle.dumps(d) >>> hashlib.md5(z).hexdigest() '8521955ed8c63c554744058c9888dc30' Perhaps a better solution exists? Note: I want to create an unique id of a dict to create a good Etag. EDIT: I can have abstract data in the dict. Something like this: reduce(lambda x,y : x^y, [hash(item) for item in d.items()]) Take the hash of each (key, value) tuple in the dict and XOR them alltogether. @katrielalex If the dict

How to generate a md5 checksum for a CSV file in JSP

﹥>﹥吖頭↗ 提交于 2019-12-04 21:59:25
I need to calculate the checksum of a csv file. The checksum will change every time the data in the file is changed. I found nothing useful over the internet in this regard. First of all, this problem is not specific to JSP. JSP is just a HTML code generator. Writing Java code in a JSP file instead of a normal Java class doesn't make it a JSP problem. You would help yourself more if you concentrate on solving future Java problems using the "Java" keyword, not using the "JSP" keyword. Said that, you can just use MessageDigest which you update with the bytes read from the file. FileInputStream

Current version of data in database has changed since user initiated update process

假如想象 提交于 2019-12-04 21:40:59
I have a Master Detail form in my Oracle APEX application. When I am trying to update data in this form, I am getting below error. Current version of data in database has changed since user initiated update process. current row version identifier = "26D0923D8A5144D6F483C2B9815D07D3" application row version identifier = "1749BCD159359424E1EE00AC1C3E3FCB" (Row 1) I have cleared browser cache and try to update. But it not worked. How can I solve this? I have experienced similar problem where my detail records set has timestamp fields. By default master detail wizard creates the timestamp fields

Ansible: How to Check a local and remote set of files for sha1 checksum

∥☆過路亽.° 提交于 2019-12-04 18:45:34
I want to be able to do a checksum based on a list of files in a local dir. Then be able to get those files checksum and compare it to the checksum of the same files on a remote system. I know I can get the with the following # Local File - stat: path: "{{ playbook_dir }}/roles/common/files/myfile.dat" checksum_algorithm: sha1 delegate_to: localhost run_once: true register: localsha_result # Remote file - stat: path: "{{ rmt_dest_dir }}/myfile.dat" checksum_algorithm: sha1 register: sha_result and I have tried to loop through the files that I want to checksum with: # Gather Files - name:

TCP Checksum calculation doesn't match with the the wireshark calculation

只谈情不闲聊 提交于 2019-12-04 17:41:22
I am experiencing a problem where the tcp checksum generated by the sample program (copied below) doesn't match with the checksum calculated by wireshark. Can some one please point me where i am going wrong. Here i tried two ways tcp_checksum get_ipv6_udptcp_checksum. with both these, getting two different values and both are not matching with the wireshark value. I am copying here the IP and TCP Header details. IP Header: 0000 60 00 00 00 00 2a 06 80 10 80 a2 b1 00 00 00 00 0010 00 00 00 00 00 1e 00 00 ff 00 00 00 00 00 00 00 0020 00 00 00 00 00 00 00 24 TCP Header: 0000 04 22 00 50 00 01 e0

MySQL - Fastest way to check if data in InnoDB table has changed

99封情书 提交于 2019-12-04 12:59:53
问题 My application is very database intensive. Currently, I'm running MySQL 5.5.19 and using MyISAM, but I'm in the process of migrating to InnoDB. The only problem left is checksum performance. My application does about 500-1000 "CHECKSUM TABLE" statements per second in peak times, because the clients GUI is polling the database constantly for changes (it is a monitoring system, so must be very responsive and fast). With MyISAM, there are Live checksums that are precalculated on table

Find out CRC or CHECKSUM of RS232 data

*爱你&永不变心* 提交于 2019-12-04 12:50:23
I need to communicate with a RS232 device, I have no specs or information available. I send a 16 byte command and get a 16 byte result back. The last byte looks like some kind of crc or checksum, I have tried using this http://miscel.dk/MiscEl/miscelCRCandChecksum.html with no luck. Anyone can reverse engineer the crc/checksum algorithm? here is some data captured with an RS-232 monitor program: 01 80 42 00 00 00 00 00 00 00 00 00 00 00 01 B3 01 80 42 00 00 00 00 00 00 00 00 00 00 00 02 51 01 80 42 00 00 00 00 00 00 00 00 00 00 00 03 0F 01 80 42 00 00 00 00 00 00 00 00 00 00 00 04 8C 01 80 42

Checksumming large swathes of prime numbers? (for verification)

纵然是瞬间 提交于 2019-12-04 12:04:45
Are there any clever algorithms for computing high-quality checksums on millions or billions of prime numbers? I.e. with maximum error-detection capability and perhaps segmentable? Motivation: Small primes - up to 64 bits in size - can be sieved on demand to the tune of millions per second, by using a small bitmap for sieving potential factors (up to 2^32-1) and a second bitmap for sieving the numbers in the target range. Algorithm and implementation are reasonably simple and straightforward but the devil is in the details: values tend to push against - or exceed - the limits of builtin

CRC checks for files

隐身守侯 提交于 2019-12-04 11:13:49
问题 I'm working with a small FAT16 filesystem, and I want to generate CRC values for indidual XML files which store configuration information. In case the data changes or is corrupted, I want to be able to check the CRC to determine that the file is still in it's original state. The question is, how do I put the CRC value into the file, without changing the CRC value of the file itself? I can think of a couple solutions, but I think there must be a fairly standard solution for this issue. 回答1:

Calculating FCS(CRC) for HDLC frame

隐身守侯 提交于 2019-12-04 08:44:57
问题 I have the following frame: 7e 01 00 00 01 00 18 ef 00 00 00 b5 20 c1 05 10 02 71 2e 1a c2 05 10 01 71 00 6e 87 02 00 01 42 71 2e 1a 01 96 27 be 27 54 17 3d b9 93 ac 7e If I understand correctly, then it is this portion of the frame on which the FCS is calculated: 010000010018ef000000b520c1051002712e1ac205100171006e8702000142712e1a019627be2754173db9 I've tried entering this into a number of online calculators but I cant produce 0x93ac from the above data. http://www.lammertbies.nl/comm/info