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What is the current behavior?

Closes #5282

The original implementation to record access by a user to a gradeable page was done using a log file that was read completely into memory on each page load and then written back out with a new entry. The file was then copied around during the autograding process, and potentially used. The format of the timestamp in the logfile was not in the right format, using MM-DD-YYYY instead of YYYY-MM-DD. Additionally, during a period of high usage, reading and writing the file was causing an unfortunate system bottleneck. This file was saved one level above the submission version folder, and so required being copied in during the grading process.

Old format:

{
    "page_load_history": [
        {
            "time": "07-04-2020 14:30:33-0400",
            "who": "instructor"
        },
        {
            "time": "07-04-2020 14:34:33-0400",
            "who": "instructor"
        }
    ]
}

What is the new behavior?

We now write to the DB each access, and this is then written out to a file on submission. The timestamp of each entry is also now in the proper format. This file is saved now within the submission folder as a dotfile (.user_assignment_access.json), which removes the need for copying it in during the grading process.

The new format:

[
    {
        "id": 4,
        "g_id": "open_homework",
        "user_id": "instructor",
        "team_id": null,
        "accessor_id": "instructor",
        "timestamp": "2020-07-04 12:35:10-0400"
    },
    {
        "id": 5,
        "g_id": "open_homework",
        "user_id": "instructor",
        "team_id": null,
        "accessor_id": "instructor",
        "timestamp": "2020-07-04 12:35:28-0400"
    }
]

Other information?

Currently I am writing out the entire gradeable_access table row to the file. I expect to get feedback on trimming it down, as well as naming of fields within the review, which will help revise things.

To Do:

• Decide if to include or not backwards compatibility with old format
• Commit DB changes to course_schema.sql
• Update submission tests for checking new generated file