1697364 - HTML Email with large table with inline image references eats up gigabytes of RAM - loads full mail into memory for each image.

Status: NEW

(Thunderbird :: General, defect)

Description

[WD]

Attachment: EML file that triggers insane consumption of RAM

Attached is a mostly-sanitized (but not necessarily minimized) HTML email that was generated from a Confluence page change. Upon rendering this email message as HTML, Thunderbird uses gigabytes and gigabytes of RAM until the OS is virtually unusable.

I'm using 78.8.1 (64-bit) on macOS Big Sur

Steps to reproduce:

1. Open attached EML file
2. Make sure that messages are viewed in Original HTML

Actual results:
Seemingly unending consumption of available RAM.

Expected results:
Reasonable amount of RAM usage

Comment 1

[Wayne Mery (:wsmwk)]

Thanks for the testcase.

These issues tend to be duplicates. Perhaps one of https://mzl.la/3rv3UCy but I'm not sure this is a good query

Comment 2

[WD]

Attachment: minimized_testcase.eml

I've whittled down my original test case to something much more minimal. It's basically this:

A large HTML table where each cell refers to an inline image in the EML file. It's only about 2MB in size, but it causes Thunderbird to eat up as much RAM as is available on my computer.

Comment 3

[Alfred Peters [:infofrommozilla]]

The test mail contains 41,340 table cells.

The image has 32x32 pixel * 32 bit = 4 kB RAW data. * 41'340 = 161 MB - Peanuts 😉

I have created two variants of the test mail. One with 10'000 and one with 15'000 cells. My TB can display these successfully.
With the 10'000-mail the TB temporarily uses ~6.3 GB RAM and with the 15'000 mail it is 13.8 GB.

The 10'000-mail is 524 kB in size. * 10'000 = ~5 GB
The 15'000-mail is 785 kB in size. * 15'000 = ~11,2 GB

It seems that TB loads the complete mail into memory for each image.

Comment 4

[Wayne Mery (:wsmwk)]

Thank you Alfred for that analysis!

https://mzl.la/3GdlFNl

• Possibly bad before version 78 - Bug 1512974 - very slow to read complicated mail with images
• Perhaps worse in 78.
• Looks like even worse in version 91 - Bug 1741136 (and others) - Locks up with in-lined images. Takes down Windows Explorer (not the web browser) in about 1 minute