The primary benefit is that objects can allocate memory for their struct with the context, which saves an additional allocation and makes it easier to read context/allocation dumps. Also, the memory context does not need to be stored with the object since it can be determined using the object pointer.
Object pointers cannot be moved, so this means whatever additional memory is allocated cannot be resized. That makes the additional memory ideal for object structs, but not so much for allocating a list that might change size.
Mem contexts can no longer be reused since they will probably be the wrong size so their memory is freed on memContextFree(). This still means fewer allocations and frees overall.
Interfaces still need to be freed by mem context so the old objMove() and objFree() have been preserved as objMoveContext() and objFreeContext(). This will be addressed in a future commit.
Replace all instances of strNew("") with strNew() and use strNewZ() for non-empty zero-terminated strings. Besides saving a useless parameter, this will allow smarter memory allocation in a future commit by signaling intent, in general, to append or not.
In the tests use STRDEF() or VARSTRDEF() where more appropriate rather than blindly replacing with strNewZ(). Also replace strLstAdd() with strLstAddZ() where appropriate for the same reason.
Inline functions are more efficient and if they are not used are automatically omitted from the binary.
This also makes the implementation of these functions easier to find and removes the need for a declaration. That is, the complete implementation is located in the header rather than being spread between the header and C file.
OBJECT_DEFINE_MOVE() and OBJECT_DEFINE_FREE() will be replaced with inlines so this would be the only macro left that is constructing functions.
It is not a great pattern anyway since it makes it hard to find the function implementation.
The original intention was to enclose complex code in braces but somehow braces got propagated almost everywhere.
Document the standard for braces in switch statements and update the code to reflect the standard.
There is not a lot to be done in this case since it looks like PostgreSQL disconnected while the query was running, but at least improve the error message and remove the assert, which indicates a coding error.
We use the Z suffix in many functions to indicate that we are expecting a zero-terminated string so make this function conform to the pattern.
As a bonus the new name is a bit shorter, which is a good quality in a commonly-used function.
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.
Previously memNew() used memset() to initialize all struct members to 0, NULL, false, etc. While this appears to work in practice, it is a violation of the C specification. For instance, NULL == 0 must be true but neither NULL nor 0 must be represented with all zero bits.
Instead use designated initializers to initialize structs. These guarantee that struct members will be properly initialized even if they are not specified in the initializer. Note that due to a quirk in the C99 specification at least one member must be explicitly initialized even if it needs to be the default value.
Since pre-zeroed memory is no longer required, adjust memAllocInternal()/memReallocInternal() to return raw memory and update dependent functions accordingly. All instances of memset() have been removed except in debug/test code where needed.
Add memMewPtrArray() to allocate an array of pointers and automatically set all pointers to NULL.
Rename memGrowRaw() to the more logical memResize().
This macro block encapsulates the common pattern of switching to the prior (formerly called old) mem context to return results from a function.
Also rename MEM_CONTEXT_OLD() to memContextPrior(). This violates our convention of macros being in all caps but memContextPrior() will become a function very soon so this will reduce churn.
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.
This direct interface to libpq allows simple queries to be run against PostgreSQL and supports timeouts.
Testing is performed using a shim that can use scripted responses to test all aspects of the client code. The shim will be very useful for testing backup scenarios on complex topologies.
Reviewed by Cynthia Shang.
