When large-file mode kicks in
There is one number: 64 MiB.
If a file is 64 MiB or larger, Erya does not read it into memory. It switches to a read-only reading mode instead, says “Opened access.log in large-file read-only mode (512 MB)”, and the mode cell of the status bar reads Large file read-only.
- A large UTF-8 text file → large-file read-only mode (this chapter).
- A large binary file → a streamed hexadecimal view, also read-only (see 3.3.8).
- A large non-UTF-8 text file (say a 200 MB Big5 export) → Erya cannot decode it as a stream, so it opens as a binary file in the hexadecimal view. Convert it to UTF-8 outside Erya if you need to edit it.
What you can do in this mode
Read it, search it, copy from it — but not change it.
Available
- Scrolling, paging, Ctrl+Home / Ctrl+End
- Ctrl+G to a line number
- Ctrl+W search and F3
- Selecting and Ctrl+C
- Ctrl+L line wrap
- Ctrl+P hexadecimal view
- New tabs, switching tabs, exiting
Refused with “Large files use read-only mode and cannot be edited”
- Typing, deleting, pasting, cutting, deleting lines
- Save and Save As
- Replace (Ctrl+R / F5 / F6)
- Undo and redo
- Encoding and line-ending conversion (F7 / F8)
- Formatting, paragraph reflow, block fill and shift
- Inserting phrases, running macros
- No syntax highlighting. Highlighting needs to parse the whole file, so it is switched off on purpose.
- No side-by-side comparison. Choosing a large file with F4 is refused: “Side-by-side comparison is unavailable in large-file mode to avoid loading the complete file into memory” (see 3.4.9).
How the memory is saved
It keeps signposts, and reads a line from disk when the screen asks for it.
Following a growing log
Erya checks the file every 250 milliseconds, and new content simply appears.
This is where large-file mode earns its place: it is tail -f that you can also search and scroll back through.
- Appends are cheap. Erya rebuilds only the last incomplete line plus whatever is new; it does not rescan the file, so size does not slow it down.
- The cursor at the end means follow. Sitting at the end of the last line, new content pushes the view along. That is follow mode.
- Move away and it holds still. Scroll back to read something and the view stays where you are, undisturbed by new arrivals. Press Ctrl+End to resume following.
- Updates are announced with “External file update detected; content refreshed”.
erya /var/log/nginx/access.log → Ctrl+End to start following → Ctrl+W and F3 when you need to find something → Ctrl+End again to resume. You never leave the editor.
Truncation and rotation
When the file does not grow but is replaced.
| What happened on disk | What Erya does | Typical cause |
|---|---|---|
| Content appended | Adds just the new part; fast | A service writing its log |
| File emptied (truncated) | Reopens and rebuilds the index | > access.log, logrotate with copytruncate |
| File rewritten in place | Reopens and rebuilds the index | A report regenerated from scratch |
| File replaced (rotation) | Reopens and rebuilds the index | logrotate moving the old file aside |
Erya follows the path. Once access.log has been rotated, what you see is the new file (usually empty or very short); the old content is in access.log.1. Open that in another tab if you need it.
External changes to ordinary files
Small files are watched too; only the response differs.
The same 250 ms check runs for ordinary files. The difference is that ordinary files can be edited, so Erya has to know whether you have (the full account is in 2.1.7):
| File type | You have not edited | You have edited |
|---|---|---|
| Ordinary text file | Reloads automatically; undo history cleared | Warns only, then asks with the red row (O/R/N) when you save |
| Large file | Refreshes automatically | Cannot happen — the mode does not allow edits |
The three external-change outcomes
One table to consult when it happens.
| Message row | Colour | What to do |
|---|---|---|
| External update detected; file safely reloaded | Yellow | Nothing. You have the current content — but the undo history is gone. |
| External file update detected; content refreshed | Yellow | Nothing; the automatic refresh in large-file mode. |
| The file changed externally; confirmation is required before saving | Yellow | A warning only, nothing blocked yet. The question comes at save time. |
| File changed externally: [O]verwrite, [R]eload, [N/Esc] cancel | Red | A decision. When unsure press N, then F12 to save a copy (2.1.7). |
| Failed to refresh external file: … | Yellow | The file was deleted, permissions changed, or the disk misbehaved. Check that it still exists. |
Common problems
Six questions about large-file mode.
| Symptom | Cause and fix |
|---|---|
| Typing does nothing; it says read-only | The file is past 64 MiB (3.2.2). To edit it, split it outside Erya or extract the part you need. |
| No syntax highlighting | Deliberately disabled in this mode (3.2.2). |
| The view keeps jumping to the end | The cursor is at the end, so it is following. Scroll back to stop it (3.2.4). |
| The view stopped updating | The cursor is no longer at the end. Press Ctrl+End (3.2.4). |
| The log suddenly went empty | Truncation or rotation; you are on the new file (3.2.5). |
| A large CJK file opened as hexadecimal | A large non-UTF-8 file cannot be decoded as a stream (3.2.1). Convert it to UTF-8 first. |