We include "hash.h" in "reftable/system.h" such that we can use hash
format IDs as well as the raw size of SHA1 and SHA256. As we are in the
process of converting the reftable library to become standalone we of
course cannot rely on those constants anymore.
Introduce a new `enum reftable_hash` to replace internal uses of the
hash format IDs and new constants that replace internal uses of the hash
size. Adapt the reftable backend to set up the correct hash function.
Signed-off-by: Patrick Steinhardt <ps@pks.im>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
The hash format IDs are used for two different things across the
reftable codebase:
- They are used as a 32 bit unsigned integer when reading and writing
the header in order to identify the hash function.
- They are used internally to identify which hash function is in use.
When one only considers the second usecase one might think that one can
easily change the representation of those hash IDs. But because those
IDs end up in the reftable header and footer on disk it is important
that those never change.
Create separate constants `REFTABLE_FORMAT_ID_*` and use them in
contexts where we read or write reftable headers. This serves multiple
purposes:
- It allows us to more easily discern cases where we actually use
those constants for the on-disk format.
- It detangles us from the same constants that are defined in
libgit.a, which is another required step to convert the reftable
library to become standalone.
- It makes the next step easier where we stop using `GIT_*_FORMAT_ID`
constants in favor of a custom enum.
Signed-off-by: Patrick Steinhardt <ps@pks.im>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Convert the reftable library such that we handle failures with the
new `reftable_buf` interfaces.
Signed-off-by: Patrick Steinhardt <ps@pks.im>
Signed-off-by: Taylor Blau <me@ttaylorr.com>
The `reftable_record_key()` function cannot pass any errors to the
caller as it has a `void` return type. Adapt it and its callers such
that we can handle errors and start handling allocation failures.
Signed-off-by: Patrick Steinhardt <ps@pks.im>
Signed-off-by: Taylor Blau <me@ttaylorr.com>
Convert the reftable library to use the `reftable_buf` interface instead
of the `strbuf` interface. This is mostly a mechanical change via sed(1)
with some manual fixes where functions for `strbuf` and `reftable_buf`
differ. The converted code does not yet handle allocation failures. This
will be handled in subsequent commits.
Signed-off-by: Patrick Steinhardt <ps@pks.im>
Signed-off-by: Taylor Blau <me@ttaylorr.com>
We have several calls to `FREE_AND_NULL()` in the reftable library,
which of course uses free(3P). As the reftable allocators are pluggable
we should rather call the reftable specific function, which is
`reftable_free()`.
Introduce a new macro `REFTABLE_FREE_AND_NULL()` and adapt the callsites
accordingly.
Signed-off-by: Patrick Steinhardt <ps@pks.im>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Handle trivial allocation failures in the reftable library and its unit
tests.
Signed-off-by: Patrick Steinhardt <ps@pks.im>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Handle allocation failures in `new_indexed_table_ref_iter()`. While at
it, rename the function to match our coding style.
Signed-off-by: Patrick Steinhardt <ps@pks.im>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Handle allocation failures in `reader_init_iter()`. This requires us to
also adapt `reftable_reader_init_*_iterator()` to bubble up the new
error codes. Adapt callers accordingly.
Signed-off-by: Patrick Steinhardt <ps@pks.im>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Handle allocation failures when creating unindexed readers.
Signed-off-by: Patrick Steinhardt <ps@pks.im>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
In 67ce50ba26 (Merge branch 'ps/reftable-reusable-iterator', 2024-05-30)
we have refactored the interface of reftable iterators such that they
can be reused in theory. This patch series only landed the required
changes on the interface level, but didn't yet implement the actual
logic to make iterators reusable.
As it turns out almost all of the infrastructure already does support
re-seeking. The only exception is the table iterator, which does not
reset its `is_finished` bit. Do so and add a couple of tests that verify
that we can re-seek iterators.
Signed-off-by: Patrick Steinhardt <ps@pks.im>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
The lifetime of a table iterator may survive the lifetime of a reader
when the stack gets reloaded. Keep the reader from being released by
increasing its refcount while the iterator is still being used.
Signed-off-by: Patrick Steinhardt <ps@pks.im>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
It was recently reported that concurrent reads and writes may cause the
reftable backend to segfault. The root cause of this is that we do not
properly keep track of reftable readers across reloads.
Suppose that you have a reftable iterator and then decide to reload the
stack while iterating through the iterator. When the stack has been
rewritten since we have created the iterator, then we would end up
discarding a subset of readers that may still be in use by the iterator.
The consequence is that we now try to reference deallocated memory,
which of course segfaults.
One way to trigger this is in t5616, where some background maintenance
jobs have been leaking from one test into another. This leads to stack
traces like the following one:
+ git -c protocol.version=0 -C pc1 fetch --filter=blob:limit=29999 --refetch origin
AddressSanitizer:DEADLYSIGNAL
=================================================================
==657994==ERROR: AddressSanitizer: SEGV on unknown address 0x7fa0f0ec6089 (pc 0x55f23e52ddf9 bp
0x7ffe7bfa1700 sp 0x7ffe7bfa1700 T0)
==657994==The signal is caused by a READ memory access.
#0 0x55f23e52ddf9 in get_var_int reftable/record.c:29
#1 0x55f23e53295e in reftable_decode_keylen reftable/record.c:170
#2 0x55f23e532cc0 in reftable_decode_key reftable/record.c:194
#3 0x55f23e54e72e in block_iter_next reftable/block.c:398
#4 0x55f23e5573dc in table_iter_next_in_block reftable/reader.c:240
#5 0x55f23e5573dc in table_iter_next reftable/reader.c:355
#6 0x55f23e5573dc in table_iter_next reftable/reader.c:339
#7 0x55f23e551283 in merged_iter_advance_subiter reftable/merged.c:69
#8 0x55f23e55169e in merged_iter_next_entry reftable/merged.c:123
#9 0x55f23e55169e in merged_iter_next_void reftable/merged.c:172
#10 0x55f23e537625 in reftable_iterator_next_ref reftable/generic.c:175
#11 0x55f23e2cf9c6 in reftable_ref_iterator_advance refs/reftable-backend.c:464
#12 0x55f23e2d996e in ref_iterator_advance refs/iterator.c:13
#13 0x55f23e2d996e in do_for_each_ref_iterator refs/iterator.c:452
#14 0x55f23dca6767 in get_ref_map builtin/fetch.c:623
#15 0x55f23dca6767 in do_fetch builtin/fetch.c:1659
#16 0x55f23dca6767 in fetch_one builtin/fetch.c:2133
#17 0x55f23dca6767 in cmd_fetch builtin/fetch.c:2432
#18 0x55f23dba7764 in run_builtin git.c:484
#19 0x55f23dba7764 in handle_builtin git.c:741
#20 0x55f23dbab61e in run_argv git.c:805
#21 0x55f23dbab61e in cmd_main git.c:1000
#22 0x55f23dba4781 in main common-main.c:64
#23 0x7fa0f063fc89 in __libc_start_call_main ../sysdeps/nptl/libc_start_call_main.h:58
#24 0x7fa0f063fd44 in __libc_start_main_impl ../csu/libc-start.c:360
#25 0x55f23dba6ad0 in _start (git+0xadfad0) (BuildId: 803b2b7f59beb03d7849fb8294a8e2145dd4aa27)
While it is somewhat awkward that the maintenance processes survive
tests in the first place, it is totally expected that reftables should
work alright with concurrent writers. Seemingly they don't.
The only underlying resource that we need to care about in this context
is the reftable reader, which is responsible for reading a single table
from disk. These readers get discarded immediately (unless reused) when
calling `reftable_stack_reload()`, which is wrong. We can only close
them once we know that there are no iterators using them anymore.
Prepare for a fix by converting the reftable readers to be refcounted.
Reported-by: Jeff King <peff@peff.net>
Signed-off-by: Patrick Steinhardt <ps@pks.im>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Same as with the preceding commit, we also provide a `reader_close()`
function that allows the caller to close a reader without freeing it.
This is unnecessary now that all users will have an allocated version of
the reader.
Inline it into `reftable_reader_free()`.
Signed-off-by: Patrick Steinhardt <ps@pks.im>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Most users use an allocated version of the `reftable_reader`, except for
some tests. We are about to convert the reader to become refcounted
though, and providing the ability to keep a reader on the stack makes
this conversion harder than necessary.
Update the tests to use `reftable_reader_new()` instead to prepare for
this change.
Signed-off-by: Patrick Steinhardt <ps@pks.im>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Rename the `reftable_new_reader()` function to `reftable_reader_new()`
to match our coding guidelines.
Signed-off-by: Patrick Steinhardt <ps@pks.im>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
The `reftable_table` interface provides a generic infrastructure that
can abstract away whether the underlying table is a single table, or a
merged table. This abstraction can make it rather hard to reason about
the code. We didn't ever use it to implement the reftable backend, and
with the preceding patches in this patch series we in fact don't use it
at all anymore. Furthermore, it became somewhat useless with the recent
refactorings that made it possible to seek reftable iterators multiple
times, as these now provide generic access to tables for us. The
interface is thus redundant and only brings unnecessary complexity with
it.
Remove the `struct reftable_table` interface and its associated
functions.
Signed-off-by: Patrick Steinhardt <ps@pks.im>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Move `reftable_reader_print_file()` into the "dump-reftable" helper.
This follows the same reasoning as the preceding commit.
Signed-off-by: Patrick Steinhardt <ps@pks.im>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
The filtering ref iterator can be used to only yield refs which are not
in a specific skip list. This iterator has an option to double-check the
results it returns, which causes us to seek the reference we are about
to yield via a separate table such that we detect whether the reference
that the first iterator has yielded actually exists.
The value of this is somewhat dubious, and I cannot think of any usecase
where this functionality should be required. Furthermore, this option is
never set in our codebase, which means that it is essentially untested.
And last but not least, the `struct reftable_table` that is used to
implement it is about to go away.
So while we could refactor the code to not use a `reftable_table`, it
very much feels like a wasted effort. Let's just drop this code.
Signed-off-by: Patrick Steinhardt <ps@pks.im>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
The merged table provides access to a reftable stack by merging the
contents of those tables into a virtual table. These subtables are being
tracked via `struct reftable_table`, which is a generic interface for
accessing either a single reftable or a merged reftable. So in theory,
it would be possible for the merged table to merge together other merged
tables.
This is somewhat nonsensical though: we only ever set up a merged table
over normal reftables, and there is no reason to do otherwise. This
generic interface thus makes the code way harder to follow and reason
about than really necessary. The abstraction layer may also have an
impact on performance, even though the extra set of vtable function
calls probably doesn't really matter.
Refactor the merged tables to use a `struct reftable_reader` for each of
the subtables instead, which gives us direct access to the underlying
tables. Adjust names accordingly.
Signed-off-by: Patrick Steinhardt <ps@pks.im>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Code clean-up to make the reftable iterator closer to be reusable.
* ps/reftable-reusable-iterator:
reftable/merged: adapt interface to allow reuse of iterators
reftable/stack: provide convenience functions to create iterators
reftable/reader: adapt interface to allow reuse of iterators
reftable/generic: adapt interface to allow reuse of iterators
reftable/generic: move seeking of records into the iterator
reftable/merged: simplify indices for subiterators
reftable/merged: split up initialization and seeking of records
reftable/reader: set up the reader when initializing table iterator
reftable/reader: inline `reader_seek_internal()`
reftable/reader: separate concerns of table iter and reftable reader
reftable/reader: unify indexed and linear seeking
reftable/reader: avoid copying index iterator
reftable/block: use `size_t` to track restart point index
Refactor the interfaces exposed by `struct reftable_reader` and `struct
table_iterator` such that they support iterator reuse. This is done by
separating initialization of the iterator and seeking on it.
Signed-off-by: Patrick Steinhardt <ps@pks.im>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Reftable iterators are created by seeking on the parent structure of a
corresponding record. For example, to create an iterator for the merged
table you would call `reftable_merged_table_seek_ref()`. Most notably,
it is not posible to create an iterator and then seek it afterwards.
While this may be a bit easier to reason about, it comes with two
significant downsides. The first downside is that the logic to find
records is split up between the parent data structure and the iterator
itself. Conceptually, it is more straight forward if all that logic was
contained in a single place, which should be the iterator.
The second and more significant downside is that it is impossible to
reuse iterators for multiple seeks. Whenever you want to look up a
record, you need to re-create the whole infrastructure again, which is
quite a waste of time. Furthermore, it is impossible to optimize seeks,
such as when seeking the same record multiple times.
To address this, we essentially split up the concerns properly such that
the parent data structure is responsible for setting up the iterator via
a new `init_iter()` callback, whereas the iterator handles seeks via a
new `seek()` callback. This will eventually allow us to call `seek()` on
the iterator multiple times, where every iterator can potentially
optimize for certain cases.
Note that at this point in time we are not yet ready to reuse the
iterators. This will be left for a future patch series.
Signed-off-by: Patrick Steinhardt <ps@pks.im>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
All the seeking functions accept a `struct reftable_reader` as input
such that they can use the reader to look up the respective blocks.
Refactor the code to instead set up the reader as a member of `struct
table_iter` during initialization such that we don't have to pass the
reader on every single call.
This step is required to move seeking of records into the generic
`struct reftable_iterator` infrastructure.
Signed-off-by: Patrick Steinhardt <ps@pks.im>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
We have both `reader_seek()` and `reader_seek_internal()`, where the
former function only exists so that we can exit early in case the given
table has no records of the sought-after type.
Merge these two functions into one.
Signed-off-by: Patrick Steinhardt <ps@pks.im>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
In "reftable/reader.c" we implement two different interfaces:
- The reftable reader contains the logic to read reftables.
- The table iterator is used to iterate through a single reftable read
by the reader.
The way those two types are used in the code is somewhat confusing
though because seeking inside a table is implemented as if it was part
of the reftable reader, even though it is ultimately more of a detail
implemented by the table iterator.
Make the boundary between those two types clearer by renaming functions
that seek records in a table such that they clearly belong to the table
iterator's logic.
Signed-off-by: Patrick Steinhardt <ps@pks.im>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
In `reader_seek_internal()` we either end up doing an indexed seek when
there is one or a linear seek otherwise. These two code paths are
disjunct without a good reason, where the indexed seek will cause us to
exit early.
Refactor the two code paths such that it becomes possible to share a bit
more code between them.
Signed-off-by: Patrick Steinhardt <ps@pks.im>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
When doing an indexed seek we need to walk down the multi-level index
until we finally hit a record of the desired indexed type. This loop
performs a copy of the index iterator on every iteration, which is both
hard to understand and completely unnecessary.
Refactor the code so that we use a single iterator to walk down the
indices, only.
Note that while this should improve performance, the improvement is
negligible in all but the most unreasonable repositories. This is
because the effect is only really noticeable when we have to walk down
many levels of indices, which is not something that a repository would
typically have. So the motivation for this change is really only about
readability.
Signed-off-by: Patrick Steinhardt <ps@pks.im>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
We're about to introduce new configs that will allow users to have more
control over how exactly reftables are written. To verify that these
configs are effective we will need to take a peak into the actual blocks
written by the reftable backend.
Introduce a new mode to the dumping logic that prints out the block
structure. This logic can be invoked via `test-tool dump-reftables -b`.
Signed-off-by: Patrick Steinhardt <ps@pks.im>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
When calling `inflateInit()` and `inflate()`, the zlib library will
allocate several data structures for the underlying `zstream` to keep
track of various information. Thus, when inflating repeatedly, it is
possible to optimize memory allocation patterns by reusing the `zstream`
and then calling `inflateReset()` on it to prepare it for the next chunk
of data to inflate.
This is exactly what the reftable code is doing: when iterating through
reflogs we need to potentially inflate many log blocks, but we discard
the `zstream` every single time. Instead, as we reuse the `block_reader`
for each of the blocks anyway, we can initialize the `zstream` once and
then reuse it for subsequent inflations.
Refactor the code to do so, which leads to a significant reduction in
the number of allocations. The following measurements were done when
iterating through 1 million reflog entries. Before:
HEAP SUMMARY:
in use at exit: 13,473 bytes in 122 blocks
total heap usage: 23,028 allocs, 22,906 frees, 162,813,552 bytes allocated
After:
HEAP SUMMARY:
in use at exit: 13,473 bytes in 122 blocks
total heap usage: 302 allocs, 180 frees, 88,352 bytes allocated
Signed-off-by: Patrick Steinhardt <ps@pks.im>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
The reftable backend stores reflog entries in a compressed format and
thus needs to uncompress blocks before one can read records from it.
For each reflog block we thus have to allocate an array that we can
decompress the block contents into. This block is being discarded
whenever the table iterator moves to the next block. Consequently, we
reallocate a new array on every block, which is quite wasteful.
Refactor the code to reuse the uncompressed block data when moving the
block reader to a new block. This significantly reduces the number of
allocations when iterating through many compressed blocks. The following
measurements are done with `git reflog list` when listing 100k reflogs.
Before:
HEAP SUMMARY:
in use at exit: 13,473 bytes in 122 blocks
total heap usage: 45,755 allocs, 45,633 frees, 254,779,456 bytes allocated
After:
HEAP SUMMARY:
in use at exit: 13,473 bytes in 122 blocks
total heap usage: 23,028 allocs, 22,906 frees, 162,813,547 bytes allocated
Signed-off-by: Patrick Steinhardt <ps@pks.im>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
The table iterator has to iterate towards the next block once it has
yielded all records of the current block. This is done by creating a new
table iterator, initializing it to the next block, releasing the old
iterator and then copying over the data.
Refactor the code to instead advance the table iterator in place. This
is simpler and unlocks some optimizations in subsequent patches. Also,
it allows us to avoid some allocations.
The following measurements show a single matching ref out of 1 million
refs. Before this change:
HEAP SUMMARY:
in use at exit: 13,603 bytes in 125 blocks
total heap usage: 7,235 allocs, 7,110 frees, 301,481 bytes allocated
After:
HEAP SUMMARY:
in use at exit: 13,603 bytes in 125 blocks
total heap usage: 315 allocs, 190 frees, 107,027 bytes allocated
Signed-off-by: Patrick Steinhardt <ps@pks.im>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
The table iterator allows the caller to iterate through all records in a
reftable table. To do so it iterates through all blocks of the desired
type one by one, where for each block it creates a new block iterator
and yields all its entries.
One of the things that is somewhat confusing in this context is who owns
the block reader that is being used to read the blocks and pass them to
the block iterator. Intuitively, as the table iterator is responsible
for iterating through the blocks, one would assume that this iterator is
also responsible for managing the lifecycle of the reader. And while it
somewhat is, the block reader is ultimately stored inside of the block
iterator.
Refactor the code such that the block reader is instead fully managed by
the table iterator. Instead of passing the reader to the block iterator,
we now only end up passing the block data to it. Despite clearing up the
lifecycle of the reader, it will also allow for better reuse of the
reader in subsequent patches.
The following benchmark prints a single matching ref out of 1 million
refs. Before:
HEAP SUMMARY:
in use at exit: 13,603 bytes in 125 blocks
total heap usage: 6,607 allocs, 6,482 frees, 509,635 bytes allocated
After:
HEAP SUMMARY:
in use at exit: 13,603 bytes in 125 blocks
total heap usage: 7,235 allocs, 7,110 frees, 301,481 bytes allocated
Note that while there are more allocation and free calls now, the
overall number of bytes allocated is significantly lower. The number of
allocations will be reduced significantly by the next patch though.
Signed-off-by: Patrick Steinhardt <ps@pks.im>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Introduce a new function `block_reader_release()` that releases
resources acquired by the block reader. This function will be extended
in a subsequent commit.
Signed-off-by: Patrick Steinhardt <ps@pks.im>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
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>
