This lets the slop library be stand-alone without dependence on coded-sequence.
The change also gets rid of the vestigial seek() method in ColumnReader.
The most common error when dealing with Slop columns is that they can fall out of sync with each other if the programmer accidentally does a conditional read and forgets to skip.
The second most common error is forgetting to close one of the columns in a reader or writer.
To deal with both cases, a new class SlopTable is added that keeps track of the lifecycle of all slop columns and performs a check when closing them that they are in sync.
Turns out throttling to only 1 lock per domain means the crawler chokes hard on large hosting websites such as wordpress. Giving these a slightly larger allowance.
Refactoring keyword extraction to extract spans information.
Modifying the intermediate storage of converted data to use the new slop library, which is allows for easier storage of ad-hoc binary data like spans and positions.
This is a bit of a katamari damacy commit that ended up dragging along a bunch of other fairly tangentially related changes that are hard to break out into separate commits after the fact. Will push as-is to get back to being able to do more isolated work.
Decorates DocumentSentences with information about which HTML tags they are nested in, and removes some redundant data on this rather memory hungry object. Separator information is encoded as a bit set instead of an array of integers.
The change also cleans up the SentenceExtractor class a fair bit. It no longer extracts ngrams, and a significant amount of redundant operations were removed as well. This is still a pretty unpleasant class to work in, but this is the first step in making it a little bit better.
To let up the pressure on domains with lot sof subdomains such as substack, medium, neocities, etc. a per-domain mutex is added that will limit crawling of these domains to one thread at a time.
The revisit logic wasn't sufficiently dampening the recrawl rate for websites that largely have not changed.
Modified it to be more reactive to the degree to which the content has changed, while applying upper and lower limits depending on the size of the crawl set.
This is not hooked in yet, and the term metadata is still left intact. It should probably shrink to a smaller representation (byte?) with the upcoming removal of the position mask.
