Move the basic in-memory index functionality into utils and rework the API to make it easier to use. There is now a seek function which moves the file offset to the exact line-end requested by the user.
The temp file generation has not been moved into utils because generalising it started to introduced a lot more callbacks and other complications.
This also changes the sheet display code so that (building index) is displayed in the status area while indexing is in progress.
Move the basic in-memory index functionality into utils and rework the API to make it easier to use. There is now a seek function which moves the file offset to the exact line-end requested by the user.
The temp file generation has not been moved into utils because generalising it started to introduced a lot more callbacks and other complications.
This also changes the sheet display code so that (building index) is displayed in the status area while indexing is in progress.