The function `block_iter_seek()` is merely a simple wrapper around
`block_reader_seek()`. Merge those two functions into a new function
`block_iter_seek_key()` that more clearly says what it is actually
doing.
Signed-off-by: Patrick Steinhardt <ps@pks.im>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
The function `block_reader_start()` does not really apply to the block
reader, but to the block iterator. It's name is thus somewhat confusing.
Rename it to `block_iter_seek_start()` to clarify.
We will rename `block_reader_seek()` in similar spirit in the next
commit.
Signed-off-by: Patrick Steinhardt <ps@pks.im>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
The code to iterate over refs with the reftable backend has seen
some optimization.
* ps/reftable-iteration-perf:
reftable/reader: add comments to `table_iter_next()`
reftable/record: don't try to reallocate ref record name
reftable/block: swap buffers instead of copying
reftable/pq: allocation-less comparison of entry keys
reftable/merged: skip comparison for records of the same subiter
reftable/merged: allocation-less dropping of shadowed records
reftable/record: introduce function to compare records by key
Code clean-up in various reftable code paths.
* ps/reftable-styles:
reftable/record: improve semantics when initializing records
reftable/merged: refactor initialization of iterators
reftable/merged: refactor seeking of records
reftable/stack: use `size_t` to track stack length
reftable/stack: use `size_t` to track stack slices during compaction
reftable/stack: index segments with `size_t`
reftable/stack: fix parameter validation when compacting range
reftable: introduce macros to allocate arrays
reftable: introduce macros to grow arrays
While working on the optimizations in the preceding patches I stumbled
upon `table_iter_next()` multiple times. It is quite easy to miss the
fact that we don't call `table_iter_next_in_block()` twice, but that the
second call is in fact `table_iter_next_block()`.
Add comments to explain what exactly is going on here to make things
more obvious. While at it, touch up the code to conform to our code
style better.
Note that one of the refactorings merges two conditional blocks into
one. Before, we had the following code:
```
err = table_iter_next_block(&next, ti);
if (err != 0) {
ti->is_finished = 1;
}
table_iter_block_done(ti);
if (err != 0) {
return err;
}
```
As `table_iter_block_done()` does not care about `is_finished`, the
conditional blocks can be merged into one block:
```
err = table_iter_next_block(&next, ti);
table_iter_block_done(ti);
if (err != 0) {
ti->is_finished = 1;
return err;
}
```
This is both easier to reason about and more performant because we have
one branch less.
Signed-off-by: Patrick Steinhardt <ps@pks.im>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
According to our usual coding style, the `reftable_new_record()`
function would indicate that it is allocating a new record. This is not
the case though as the function merely initializes records without
allocating any memory.
Replace `reftable_new_record()` with a new `reftable_record_init()`
function that takes a record pointer as input and initializes it
accordingly.
Signed-off-by: Patrick Steinhardt <ps@pks.im>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Similar to the preceding commit, let's carry over macros to allocate
arrays with `REFTABLE_ALLOC_ARRAY()` and `REFTABLE_CALLOC_ARRAY()`. This
requires us to change the signature of `reftable_calloc()`, which only
takes a single argument right now and thus puts the burden on the caller
to calculate the final array's size. This is a net improvement though as
it means that we can now provide proper overflow checks when multiplying
the array size with the member size.
Convert callsites of `reftable_calloc()` to the new signature and start
using the new macros where possible.
Signed-off-by: Patrick Steinhardt <ps@pks.im>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
The way the index gets written and read is not trivial at all and
requires the reader to piece together a bunch of parts to figure out how
it works. Add some documentation to hopefully make this easier to
understand for the next reader.
Signed-off-by: Patrick Steinhardt <ps@pks.im>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
When doing an indexed seek we first need to do a linear seek in order to
find the index block for our wanted key. We do not check the returned
error of the linear seek though. This is likely not an issue because the
next call to `table_iter_next()` would return error, too. But it very
much is a code smell when an error variable is being assigned to without
actually checking it.
Safeguard the code by checking for errors.
Signed-off-by: Patrick Steinhardt <ps@pks.im>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Remove unused header "#include".
* en/header-cleanup:
treewide: remove unnecessary includes in source files
treewide: add direct includes currently only pulled in transitively
trace2/tr2_tls.h: remove unnecessary include
submodule-config.h: remove unnecessary include
pkt-line.h: remove unnecessary include
line-log.h: remove unnecessary include
http.h: remove unnecessary include
fsmonitor--daemon.h: remove unnecessary includes
blame.h: remove unnecessary includes
archive.h: remove unnecessary include
treewide: remove unnecessary includes in source files
treewide: remove unnecessary includes from header files
Each of these were checked with
gcc -E -I. ${SOURCE_FILE} | grep ${HEADER_FILE}
to ensure that removing the direct inclusion of the header actually
resulted in that header no longer being included at all (i.e. that
no other header pulled it in transitively).
...except for a few cases where we verified that although the header
was brought in transitively, nothing from it was directly used in
that source file. These cases were:
* builtin/credential-cache.c
* builtin/pull.c
* builtin/send-pack.c
Signed-off-by: Elijah Newren <newren@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
There are a bunch of locations where we initialize members of `struct
block_iter`, which makes it harder than necessary to expand this struct
to have additional members. Unify the logic via a new `BLOCK_ITER_INIT`
macro that initializes all members.
Signed-off-by: Patrick Steinhardt <ps@pks.im>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
The reader code passes around a "struct reftable_reader" context
variable. But the seek function doesn't need it; the table iterator we
already get is sufficient.
Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
The spec says 2 <= object_id_len <= 31. We are lenient and allow 1,
but we forbid 0, so we can be sure that we never read a 0-length key.
Signed-off-by: Han-Wen Nienhuys <hanwen@google.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
This reduces the amount of glue code, because we don't need a void
pointer or vtable within the structure.
The only snag is that reftable_index_record contain a strbuf, so it
cannot be zero-initialized. To address this, use reftable_new_record()
to return fresh instance, given a record type. Since
reftable_new_record() doesn't cause heap allocation anymore, it should
be balanced with reftable_record_release() rather than
reftable_record_destroy().
Thanks to Peff for the suggestion.
Helped-by: Jeff King <peff@peff.net>
Signed-off-by: Han-Wen Nienhuys <hanwen@google.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
This fixes NULL derefs in error paths. Spotted by Coverity.
Signed-off-by: Han-Wen Nienhuys <hanwen@google.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Add test coverage for corrupt zlib data. Fix memory leaks demonstrated by
unittest.
This problem was discovered by a Coverity scan.
Signed-off-by: Han-Wen Nienhuys <hanwen@google.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
This supports reading a single reftable file.
The commit introduces an abstract iterator type, which captures the usecases
both of reading individual refs, and iterating over a segment of the ref
namespace.
Signed-off-by: Han-Wen Nienhuys <hanwen@google.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
