It looks like it's possible for mmap to succeed on 32-bit systems even
when the full file can't be addressed in memory. This used to work prior
to ripgrep 13, but (maybe) something about statically linking vcruntime
has caused this to now fail.
It's no big deal to disable mmap searching on 32-bit, so we just do that
instead of returning incorrect results.
Fixes#1911
This commit hacks in a bug fix for handling look-around across multiple
lines. The main problem is that by the time the matching lines are sent
to the printer, the surrounding context---which some look-behind or
look-ahead might have matched---could have been dropped if it wasn't
part of the set of matching lines. Therefore, when the printer re-runs
the regex engine in some cases (to do replacements, color matches, etc
etc), it won't be guaranteed to see the same matches that the searcher
found.
Overall, this is a giant clusterfuck and suggests that the way I divided
the abstraction boundary between the printer and the searcher is just
wrong. It's likely that the searcher needs to handle more of the work of
matching and pass that info on to the printer. The tricky part is that
this additional work isn't always needed. Ultimately, this means a
serious re-design of the interface between searching and printing. Sigh.
The way this fix works is to smuggle the underlying buffer used by the
searcher through into the printer. Since these bugs only impact
multi-line search (otherwise, searches are only limited to matches
across a single line), and since multi-line search always requires
having the entire file contents in a single contiguous slice (memory
mapped or on the heap), it follows that the buffer we pass through when
we need it is, in fact, the entire haystack. So this commit refactors
the printer's regex searching to use that buffer instead of the intended
bundle of bytes containing just the relevant matching portions of that
same buffer.
There is one last little hiccup: PCRE2 doesn't seem to have a way to
specify an ending position for a search. So when we re-run the search to
find matches, we can't say, "but don't search past here." Since the
buffer is likely to contain the entire file, we really cannot do
anything here other than specify a fixed upper bound on the number of
bytes to search. So if look-ahead goes more than N bytes beyond the
match, this code will break by simply being unable to find the match. In
practice, this is probably pretty rare. I believe that if we did a
better fix for this bug by fixing the interfaces, then we'd probably try
to have PCRE2 find the pertinent matches up front so that it never needs
to re-discover them.
Fixes#1412
This commit fixes a subtle bug in multi-line replacement of line
terminators.
The problem is that even though ripgrep supports multi-line searches, it
is *still* line oriented. It still needs to print line numbers, for
example. For this reason, there are various parts in the printer that
iterate over lines in order to format them into the desired output.
This turns out to be problematic in some cases. #1311 documents one of
those cases (with line numbers enabled to highlight a point later):
$ printf "hello\nworld\n" | rg -n -U "\n" -r "?"
1:hello?
2:world?
But the desired output is this:
$ printf "hello\nworld\n" | rg -n -U "\n" -r "?"
1:hello?world?
At first I had thought that the main problem was that the printer was
taking ownership of writing line terminators, even if the input already
had them. But it's more subtle than that. If we fix that issue, we get
output like this instead:
$ printf "hello\nworld\n" | rg -n -U "\n" -r "?"
1:hello?2:world?
Notice how '2:' is printed before 'world?'. The reason it works this way
is because matches are reported to the printer in a line oriented way.
That is, the printer gets a block of lines. The searcher guarantees that
all matches that start or end in any of those lines also end or start in
another line in that same block. As a result, the printer uses this
assumption: once it has processed a block of lines, the next match will
begin on a new and distinct line. Thus, things like '2:' are printed.
This is generally all fine and good, but an impedance mismatch arises
when replacements are used. Because now, the replacement can be used to
change the "block of lines" approach. Now, in terms of the output, the
subsequent match might actually continue the current line since the
replacement might get rid of the concept of lines altogether.
We can sometimes work around this. For example:
$ printf "hello\nworld\n" | rg -U "\n(.)?" -r '?$1'
hello?world?
Why does this work? It's because the '(.)' after the '\n' causes the
match to overlap between lines. Thus, the searcher guarantees that the
block sent to the printer contains every line.
And there in lay the solution: all we need to do is tweak the multi-line
searcher so that it combines lines with matches that directly adjacent,
instead of requiring at least one byte of overlap. Fixing that solves
the issue above. It does cause some tests to fail:
* The binary3 test in the searcher crate fails because adjacent line
matches are now one part of block, and that block is scanned for
binary data. To preserve the essence of the test, we insert a couple
dummy lines to split up the blocks.
* The JSON CRLF test. It was testing that we didn't output any messages
with an empty 'submatches' array. That is indeed still the case. The
difference is that the messages got combined because of the adjacent
line merging behavior. This is a slight change to the output, but is
still correct.
Fixes#1311
Previously, we were only looking for the UTF-16 BOM for determining
whether to do transcoding or not. But we should also look for the UTF-8
BOM as well.
Fixes#1638, Closes#1697
Sadly, there were several tests that are coupled to the size of the
buffer used by ripgrep. Making the tests agnostic to the size is
difficult. And it's annoying to fix the tests. But we rarely change the
buffer size, so ¯\_(ツ)_/¯.
This increases the initial buffer size from 8KB to 64KB. This actually
leads to a reasonably noticeable improvement in at least one work-load,
and is unlikely to regress in any other case. Also, since Rust programs
(at least on Linux) seem to always use a minimum of 6-8MB of memory,
adding an extra 56KB is negligible.
Before:
$ hyperfine -i "rg 'zqzqzqzq' OpenSubtitles2018.raw.en --no-mmap"
Benchmark #1: rg 'zqzqzqzq' OpenSubtitles2018.raw.en --no-mmap
Time (mean ± σ): 2.109 s ± 0.012 s [User: 565.5 ms, System: 1541.6 ms]
Range (min … max): 2.094 s … 2.128 s 10 runs
After:
$ hyperfine -i "rg 'zqzqzqzq' OpenSubtitles2018.raw.en --no-mmap"
Benchmark #1: rg 'zqzqzqzq' OpenSubtitles2018.raw.en --no-mmap
Time (mean ± σ): 1.802 s ± 0.006 s [User: 462.3 ms, System: 1337.9 ms]
Range (min … max): 1.795 s … 1.814 s 10 runs
memmap is unmaintained at this point and it is being flagged as a
RUSTSEC advisory in ripgrep. This doesn't seem like that big of a deal
to me honestly, but memmap2 looks like a fine choice at this point.
Fixes#1785, Closes#1786
The top-level listing was just getting a bit too long for my taste. So
put all of the code in one directory and shrink the large top-level mess
to a small top-level mess.
NOTE: This commit only contains renames. The subsequent commit will
actually make ripgrep build again. We do it this way with the naive hope
that this will make it easier for git history to track the renames.
Sigh.
