* add support for delta-1 encoding posting list
* encode term frequency minus one
* don't emit tf for json integer terms
* make skipreader not pub(crate) mutable
Tantivy used to assume that all files could be somehow memory mapped. After this change, Directory return a `FileSlice` that can be reduced and eventually read into an `OwnedBytes` object. Long and blocking io operation are still required by they do not span over the entire file.
* WIP implemented is_compatible
hide Footer::from_bytes from public consumption - only found Footer::extract
used outside the module
Add a new error type for IncompatibleIndex
add a prototypical call to footer.is_compatible() in ManagedDirectory::open_read
to make sure we error before reading it further
* Make error handling more ergonomic
Add an error subtype for OpenReadError and converters to TantivyError
* Remove an unnecessary assert
it's follower by the same check that Errors instead of panicking
* Correct the compatibility check logic
Leave a defensive versioned footer check to make sure we add new logic handling
when we add possible footer versions
Restricted VersionedFooter::from_bytes to be used inside the crate only
remove a half-baked test
* WIP.
* Return an error if index incompatible - closes#662
Enrich the error type with incompatibility
Change return type to Result<bool, TantivyError>, instead of bool
Add an Incompatibility enum that enriches the IncompatibleIndex error variant
with information, which then allows us to generate a developer-friendly hint how
to upgrade library version or switch feature flags for a different compression
algorithm
Updated changelog
Change the signature of is_compatible
Added documentation to the Incompatibility
Added a conditional test on a Footer with lz4 erroring
* Add skip information for posting list (skip to doc ids)
* Separate num bits from data for positions (skip n positions)
* Address in the position using a n-position offset
* Added a long skip structure to allow efficient opening of the position for a given term.
