We're including a couple of standard headers like <stdint.h> in a bunch
of locations, which makes it hard for a project to plug in their own
logic for making required functionality available. For us this is for
example via "compat/posix.h", which already includes all of the system
headers relevant to us.
Introduce a new "reftable-system.h" header that allows projects to
provide their own headers. This new header is supposed to contain all
the project-specific bits to provide the POSIX-like environment, and some
additional supporting code. With this change, we thus have the following
split in our system-specific code:
- "reftable/reftable-system.h" is the project-specific header that
provides a POSIX-like environment. Every project is expected to
provide their own implementation.
- "reftable/system.h" contains the project-independent definition of
the interfaces that a project needs to implement. This file should
not be touched by a project.
- "reftable/system.c" contains the project-specific implementation of
the interfaces defined in "system.h". Again, every project is
expected to provide their own implementation.
Signed-off-by: Patrick Steinhardt <ps@pks.im>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
The `reftable_block` structure associates a byte slice with a block
source. As such it only holds the data of a reftable block without
actually encoding any of the details for how to access that data.
Rename the structure to instead be called `reftable_block_data`. Besides
clarifying that this really only holds data, it also allows us to rename
the `reftable_block_reader` to `reftable_block` in the next commit, as
this is the structure that actually encapsulates access to the reftable
blocks.
Rename the `struct reftable_block_reader::block` member accordingly.
Signed-off-by: Patrick Steinhardt <ps@pks.im>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
The code that implements block sources is distributed across a couple of
files. Consolidate all of it into "reftable/blocksource.c" and its
accompanying header so that it is easier to locate and more self
contained.
While at it, rename some of the functions to have properly scoped names.
Signed-off-by: Patrick Steinhardt <ps@pks.im>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
The license headers used across the reftable library doesn't follow our
typical coding style for multi-line comments. Fix it.
Signed-off-by: Patrick Steinhardt <ps@pks.im>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
The `block_source_read_block()` function and its implementations return
an integer as a result that reflects either the number of bytes read, or
an error. As such its return type, a signed integer, isn't wrong, but it
doesn't give the reader a good hint what it actually returns.
Refactor the function to return an `ssize_t` instead, which is typical
for functions similar to read(3p) and should thus give readers a better
signal what they can expect as a result.
Adjust callers to better handle the returned value to avoid warnings
with -Wsign-compare. One of these callers is `reader_get_block()`, whose
return value is only ever used by its callers to figure out whether or
not the read was successful. So instead of bubbling up the `ssize_t`
there, too, we adapt it to only indicate success or errors.
Signed-off-by: Patrick Steinhardt <ps@pks.im>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
The block length is used to track the number of bytes available in a
specific block. As such, it is never set to a negative value, but is
still represented by a signed integer.
Adjust the type of the variable to be `size_t`.
Signed-off-by: Patrick Steinhardt <ps@pks.im>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
The reftable format is usually used with files for storage. However, we abstract
away this using the blocksource data structure. This has two advantages:
* log blocks are zlib compressed, and handling them is simplified if we can
discard byte segments from within the block layer.
* for unittests, it is useful to read and write in-memory. The blocksource
allows us to abstract the data away from on-disk files.
Signed-off-by: Han-Wen Nienhuys <hanwen@google.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
