fix: tracelog truncation makes output longer than original

[xbrxr03]

Problem

logQueryArgs truncates long strings and byte slices, but the truncation suffix makes the output longer than the original value:

• A 65-byte string truncated to 64 bytes + " (truncated 1 bytes)" = 84 bytes — 29 bytes longer than the original
• A 65-byte slice shows 128 hex chars + " (truncated 1 bytes)" = 150+ chars — much longer than the 130-char full hex encoding

Reported in #2095.

Fix

Replace the verbose fmt.Sprintf suffix with an ellipsis (…) and ensure the truncated result is always strictly shorter than the original:

• []byte: Show first 60 bytes as hex (120 chars) + … = 123 chars, always shorter than the 130+ char full hex
• string: Truncate at a rune boundary so that len(result) < len(original), using maxCut = len(v) - 4 to account for the 3-byte ellipsis

Also fixed the off-by-one: []byte threshold was < 64 (excluding 64-byte slices) but string was > 64 (excluding 65+ byte strings). Now both use <= 64 / > 64 consistently.

Tests

Added TestLogQueryArgsTruncation with 5 subtests:

• Short strings and bytes pass through unchanged
• Long strings truncate with … and are strictly shorter than the original
• Long bytes truncate with … and are shorter than full hex
• UTF-8 strings truncate at rune boundaries

Fixes #2095

[xbrxr03]

Closing this PR due to lack of maintainer engagement. I'm happy to reopen if there's interest. Thanks for the great project.

[jackc]

Closing this PR due to lack of maintainer engagement. I'm happy to reopen if there's interest. Thanks for the great project.

🤷‍♂️

It's a non-commercial project. I maintain it on nights and weekends. So if it's not an emergency it may take a few weeks for me to take a look.

As far as this particular issue though, if anything is to be done, I would see it as two changes.

1. Add a field to TraceLogConfig that controls the maximum length of the value before truncation. This would also resolve Feature Request: Remove Truncation from Args When Logging #998.
2. Retain the number of bytes truncated notification. Knowing a query had 200 byte argument vs. a 200 MB argument is important information.