This allows a local/remote to be started independently of server initialization, which will be useful for implementing new transport types, e.g. TLS.
Also remove some dead code in localTest.c.
Switch from JSON-based to binary protocol for communicating with local and remote process. The pack type is used to implement the binary protocol.
There are a number advantages:
* The pack type is more compact than JSON and are more efficient to render/parse.
* Packs are more strictly typed than JSON.
* Each protocol message is written entirely within ProtocolServer/ProtocolClient so is less likely to get interrupted by an error and leave the protocol in a bad state.
* There is no limit on message size. Previously this was limited by buffer size without a custom implementation, as was done for read/writing files.
Some cruft from the Perl days was removed, specifically allowing NULL messages and stack traces. This is no longer possible in C.
There is room for improvement here, in particular locking down the allowed sequence of protocol messages and building a state machine to enforce it. This will be useful for resetting the protocol when it gets in a bad state.
Centralize the formatting of the configuration value for display to the user or passing on a command line.
For the new functions, if the value was set by the user via the command line, config, etc., then that exact value will be displayed. This makes it easier for the user to recognize the value and saves having to format it into something reasonable, especially for time and size option types.
Note that cfgOptTypeHash and cfgOptTypeList option types are not supported by these functions, but they are generally not displayed to the user as a whole.
This also fixes a bug in config/load.c where time values where not being formatted correctly in an error message.
Make protocol handlers have one function per command. This allows the logic of finding the handler to be in ProtocolServer, isolates each command to a function, and removes the need to test the "not found" condition for each handler.
The C code does not use doubles to represent seconds like the Perl code did so time can be represented as an integer which reduces the number of data types that config has to understand.
Also remove Variant doubles since they are no longer used.
Note that not all double code was removed since we still need to display times to the user in seconds and it is possible for the times to be fractional. In the future this will likely be simplified by storing the original user input and using that value when the time needs to be displayed.
Improve locking on remote processes by introducing an exec-id that is unique to the main process and passed to all remote processes. This allows the remote processes to determine if a lock is held by a remote from the same main process. If so, the lock is allowed.
The exec-id is also useful for associating remote logs with main logs for debugging purposes.
Move sckSessionReadyRead()/Write() into the IoRead/IoWrite interfaces. This is a more logical place for them and the alternative would be to add them to the IoSession interface, which does not seem like a good idea.
This is mostly a refactor, but a big change is the select() logic in fdRead.c has been replaced by ioReadReady(). This was duplicated code that was being used by our protocol but not TLS. Since we have not had any problems with requiring poll() in the field this seems like a good time to remove our dependence on select().
Also, IoFdWrite now requires a timeout so update where required, mostly in the tests.
Pretty much everywhere handle is used what is really meant is file descriptor (fd). This terminology got migrated over from Perl and is just not quite correct, or at least not as correct as fd.
There were also plenty of places fd was used so now all uses are consistent.
The Perl code was not updated but might be in a future commit.
If a local command, e.g. backupFile(), fails it will stop the entire process. Instead, retry local commands to deal with transient errors.
Remove special logic in the S3 storage driver to retry RequestTimeTooSkewed errors since this is now handled by the general retry mechanism in the places where it is most likely to happen, i.e. file read/write. Also, this error should have been entirely eliminated by the asynchronous TLS implementation.
This has been the policy for some time but due to migration pressure only new functions and refactors have been following this rule. Now it seems sensible to make a clean sweep and move all the comments that have not been moved already (i.e. most of them).
Only obvious typos and gross inaccuracies in the comments have been fixed. For this most part this was a copy and paste operation.
Useless comments, e.g. "New object", were not copied. Even so, there are surely many deficient comments left.
Some rearranging was done where needed and functions were placed in the proper sections, e.g. "Constructors", "Functions", etc.
A few function prototypes were found that not longer had an implementation. These were removed, but there may be more.
The coding document has been updated to reflect this policy, which is not new but has never been documented.
The local, remote, archive-get-async, and archive-push-async commands were used to run functionality that was not directly available to the user. Unfortunately that meant they would not pick up options from the command that the user expected, e.g. backup, archive-get, etc.
Remove the internal commands and add roles which allow pgBackRest to determine what functionality is required without implementing special commands. This way the options are loaded from the expected command section.
Since remote is no longer a specific command with its own options, more manipulation is required when calling remote. This might be something we can improve in the config system but it may be worth leaving as is because it is a one-off, for now at least.
Migrate functionality from the Perl Db module to C. For now this is just enough to implement the WAL switch check.
Add the dbGet() helper function to get Db objects easily.
Create macros in harnessPq to make writing pq scripts easier by grouping commonly used functions together.
Reviewed by Cynthia Shang.
Remove "File" and "Driver" from object names so they are shorter and easier to keep consistent.
Also remove the "driver" directory so storage implementations are visible directly under "storage".
The function pointer casting used when creating drivers made changing interfaces difficult and led to slightly divergent driver implementations. Unit testing caught production-level errors but there were a lot of small issues and the process was harder than it should have been.
Use void pointers instead so that no casts are required. Introduce the THIS_VOID and THIS() macros to make dealing with void pointers a little safer.
Since we don't want to expose void pointers in header files, driver functions have been removed from the headers and the various driver objects return their interface type. This cuts down on accessor methods and the vast majority of those functions were not being used. Move functions that are still required to .intern.h.
Remove the special "C" crypto functions that were used in libc and instead use the standard interface.
Use autoconf to provide a basic configure script. WITH_BACKTRACE is yet to be migrated to configure and the unit tests still use a custom Makefile.
Each C file must include "build.auto.conf" before all other includes and defines. This is enforced by test.pl for includes, but it won't detect incorrect define ordering.
Update packages to call configure and use standard flags to pass options.
Asserts were only only reported on stderr rather than being returned through the protocol layer. This did not appear to be very reliable.
Instead, report the assert through the protocol layer like any other error. Add a stack trace if an assert error or debug logging is enabled.
The STRING_CONST() macro worked fine for constants but was not able to constify strings created at runtime.
Add the STR() macro to do this by using strlen() to get the size.
Also rename STRING_CONST() to STRDEF() for brevity and to match the other macro name.
When a repository server is configured, commands that modify the repository acquire a remote lock as well as a local lock for extra protection against multiple writers.
Instead of the custom logic used in Perl, make remote locking part of the command configuration.
This also means that the C remote needs the stanza since it is used to construct the lock name. We may need to revisit this at a later date.
Prior to this the Perl remote was used to satisfy C requests. This worked fine but since the remote needed to be migrated to C anyway there was no reason to wait.
Add the ProtocolServer object and tweak ProtocolClient to work with it. It was also necessary to add a mechanism to get option values from the remote so that encryption settings could be read and used in the storage object.
Update the remote storage objects to comply with the protocol changes and add the storage protocol handler.
Ideally this commit would have been broken up into smaller chunks but there are cross-dependencies in the protocol layer and it didn't seem worth the extra effort.
