Boost serialization libray 1.32 & 1.39 compatibility issue ( from "To DO" list)
Hi, I am facing backward compatibility problem with boost serialization library 1.39. My setup is something like this, (1) I have one version of my program that is built using boost 1.32 serialization library, lets call it 1_32.exe (2) I have another version of my program that is built using boost 1.39 serialization library, lets call it 1_39.exe (3) These two versions of my program communicate with each other over network and they use boost text serialization to exchange data. (4) Program 1_39.exe is able to deserialize data sent by 1_32.exe but 1_32.exe is not able to deserialize data sent by 1_39.exe While debugging this problem I realized that program 1_39.exe is putting archive version as “5” and 1_32.exe is putting archive version as “3”. This results into 1_32.exe throwing “Unknown version” exception. While going through boost documentation I read about “Back Versioning” description provided at http://www.boost.org/doc/libs/1_39_0/libs/serialization/doc/todo.html#backve... Looks like its not very difficult to address this issue if we modify some code in boost serialization library. Are you planning to address this in near future or can you please advice me on the files those need to be changed? Or is there any simple workaround as a stop gap measure to fix this issue? Thanks, Sameer
"sam p"
On 25/09/09 6:01 AM, sam p wrote:
I am facing backward compatibility problem with boost serialization library 1.39.
My setup is something like this,
(1) I have one version of my program that is built using boost 1.32 serialization library, lets call it 1_32.exe
(2) I have another version of my program that is built using boost 1.39 serialization library, lets call it 1_39.exe
(3) These two versions of my program communicate with each other over network and they use boost text serialization to exchange data.
(4) Program 1_39.exe is able to deserialize data sent by 1_32.exe but 1_32.exe is not able to deserialize data sent by 1_39.exe
While debugging this problem I realized that program 1_39.exe is putting archive version as “5” and 1_32.exe is putting archive version as “3”. This results into 1_32.exe throwing “Unknown version” exception. While going through boost documentation I read about “Back Versioning” description provided at http://www.boost.org/doc/libs/1_39_0/libs/serialization/doc/todo.html#backve...
Looks like its not very difficult to address this issue if we modify some code in boost serialization library.
The problem you're describing is actually forward compatibility which is the ability of a program to load data in a format intended for a later version. Boost Serialization doesn't support this and personally, I think implementing "back versioning" as linked above would be a waste of time. It would be far better to support forward compatibility. I believe it is somewhat possible without modifying the current library, but to be honest, I've never used the idea in production. Generally, when implementing forward compatibility, you can do it using named key/value pairs or by reading up to a certain point in a buffer. The first you can do by modifying your own code, the second you can do by creating a custom archive. -- Sohail Somani http://uint32t.blogspot.com
participants (3)
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Robert Ramey -
sam p -
Sohail Somani