The flat_mutation_reader files were conflated and contained multiple
readers, which were not strictly necessary. Splitting optimizes both
iterative compilation times, as touching rarely used readers doesn't
recompile large chunks of codebase. Total compilation times are also
improved, as the size of flat_mutation_reader.hh and
flat_mutation_reader_v2.hh have been reduced and those files are
included by many file in the codebase.
With changes
real 29m14.051s
user 168m39.071s
sys 5m13.443s
Without changes
real 30m36.203s
user 175m43.354s
sys 5m26.376s
Closes#10194
Instead of lengthy blurbs, switch to single-line, machine-readable
standardized (https://spdx.dev) license identifiers. The Linux kernel
switched long ago, so there is strong precedent.
Three cases are handled: AGPL-only, Apache-only, and dual licensed.
For the latter case, I chose (AGPL-3.0-or-later and Apache-2.0),
reasoning that our changes are extensive enough to apply our license.
The changes we applied mechanically with a script, except to
licenses/README.md.
Closes#9937
As part of changing the codebase to flat_mutation_reader_v2,
change chained_delegating_reader and its user virtual_table.
Since the reader does not process fragments (only forwarding
things around), only glue code is affected. It is also not
performance sensitive, so the extra conversions are unimportant.
Test: unit (dev)
Closes#9706
This change adds a new type of mutation reader which purpose
is to allow inserting operations before an invocation of the proper
reader. It takes a future to wait on and only after it resolves will
it forward the execution to the underlying flat_mutation_reader
implementation.
