- support std::string_view (c++17) or span view (older c++) of stream
buffer contents. This simplifies formatting + reparsing.
Example,
OCharStream os;
os << ...;
ISpanStream is(os.view());
is >> ...;
- additional release() method for ICharStream, OCharStream
that returns the contents as a DynamicList<char> and resets the stream.
- provide a str() method for API compatibility with older
std::ostringstream etc.
- change write(const string&) to write(const std::string&).
This allows output of std::string without an intermediate copy.
- additional writeQuoted method to handle range of char data:
writeQuoted(const char* str, std::streamsize len, bool)
This helps with supporting string_view and span<char>
- add operator<< for stdFoam::span<char> and std::string_view (c++17)
- avoid duplicate code in OBJstream
STYLE: add override keyword for IO stream methods
- default construct is now identical to HashTable(Foam::zero).
It performs no allocation and is also noexcept.
The previously used default capacity (128) was a holdover from
much older versions where set/insert did not properly handle
insertion into a table with zero capacity (number of buckets).
- earlier deletion of unpopulated HashTable on resizing:
If the table is already clear (ie, has no entries),
can immediately remove the old internal table before reallocating
the newly sized table, which may avoid a needless memory spike.
- reserve() method:
Naming and general behaviour as per std::unordered_map.
It behaves similarly to the resize() method but is supplied the
number of elements instead of the capacity, which can be a more
natural way of specifying the storage requirements.
Additionally, reserve() will only increase the table capacity for
behaviour similar to DynamicList and std::vector, std::string etc.
Old:
labelHashSet set;
set.resize(2*nElems);
Now:
labelHashSet set;
set.reserve(nElems);
- remove unused HashTable(Istream&, label) constructor
STYLE: static_cast of (nullptr) and std::fill_n for filling table
- changes the addressed list size without affecting list allocation.
Can be useful for the following type of coding pattern:
- pre-allocate a List with some max content length
- populate with some content (likely not the entire pre-allocated size)
- truncate the list to the length of valid content
- process the List
- discard the List
Since the List is being discarded, using resize_unsafe() instead of
resize() avoids an additional allocation with the new size and
copying/moving of the elements.
This programming pattern can also be used when the List is being
returned from a subroutine, and carrying about a bit of unused memory
is less important than avoiding reallocation + copy/move.
If used improperly, it can obviously result in addressing into
unmanaged memory regions (ie, 'unsafe').
- shrink_to_fit()
corresponds to std::vector naming.
For DynamicList it is a *binding* request.
- shrink_unsafe()
simply adjusts the capacity() to match the
current size() without forcing a re-allocation.
Useful when collapsing to a non-dynamic list to avoid reallocation
and copying contents. The memory cleanup will still occur properly
at a later stage.
- DynamicList::swap(List&)
simple recovery of content into a non-dynamic List that also
ensures that the capacity is correctly updated.
STYLE: promote List::capacity() to public visibility (like std::vector)
STYLE: remove unused expandStorage() method
- simply a wrapper for resize(capacity())
- when running with "errors warn;" it will reset the warnings counter
(if any) when it returns to a good state.
This re-enables un-suppressed warnings for the next cycle.
Also reset the warnings counter on end().
ENH: add short-circuit in HashTable::erase(key)
- skip and return false if the table is empty or the key is not found.
This makes for faster no-op behaviour.
- for workflows with appearing/disappearing patches (for example)
can specify that empty surfaces should be ignored or warned about
instead of raising a FatalError.
Note that this handling is additional to the regular top-level
"errors" specification. So specifying 'strict' will only actually
result in a FatalError if the "errors" does not trap errors.
- "ignore" : any empty surfaces are simply ignored and no
file output (besides the header).
- "warn" : empty surfaces are warned about a few times (10)
and the file output contains a NaN entry
- "strict" : corresponds to the default behaviour.
Throws a FatalError if the surface is empty.
This error may still be caught by the top-level "errors" handling.
- support UList shallowCopy with pointer/size
(eg, for slicing into or from span)
ENH: add SubList::reset() functionality
- allows modification of a SubList after construction.
Previously a SubList had an immutable location after construction
and there was no way to shift or change its location.
BUG: missed special handling for DynamicList<char>::readList (fixes#2974)
- equivalent to List<char>::readList, in which the stream is
temporarily toggled from ASCII to BINARY when reading in a List of
char data.
This specialization was missed when DynamicList<T>::readList() was
fully implemented.
- defines values for EMPTY, UNIFORM, NONUNIFORM and MIXED
that allow bitwise OR reduction and provide an algorithm
for calculating uniformity
ENH: consolidate more efficient uniformity checks in PackedList
ENH: improve linebreak handling when outputting small matrices
- use ignore instead of seekg/tellg to swallow input (robuster)
- check for bad gcount() values
- wrap Foam::fileSize() compressed/uncompressed handling into IFstream.
- improve handling of compressed files in masterUncollatedFileOperation.
Previously read into a string via stream iterators.
Now read chunk-wise into a List of char for fewer reallocations.
- soft renames (ie, old names still available via typedefs) for more
reasonable names and more coverage with std stream variants.
The old names could be a bit cryptic.
For example, uiliststream (== an unallocated/external list storage),
which is written as std::ispanstream for C++23.
Could similarly argue that IListStream is better named as
ICharStream, since it is an input stream of characters and the
internal storage mechanism (List or something else) is mostly
irrelevant.
Extending the coverage to include all std stream variants, and
simply rewrap them for OpenFOAM IOstream types. This simplifies the
inheritance patterns and allows reuse of icharstream/ocharstream as
a drop-in replace for istringstream/ostringstream in other wrappers.
Classes:
* icharstream / ICharStream [old: none / IListStream]
* ocharstream / OCharStream [old: none / OListStream]
* ispanstream / ISpanStream [old: uiliststream / UIListStream]
* ospanstream / OSpanStream [old: none / UOListStream]
Possible new uses : read file contents into a buffer, broadcast
buffer contents to other ranks and then transfer into an icharstream
to be read from. This avoid the multiple intermediate copies that
would be associated when using an istringstream.
- Use size doubling instead of block-wise incremental for ocharstream
(OCharStream). This corresponds to the sizing behaviour as per
std::stringstream (according to gcc-11 includes)
STYLE: drop Foam_IOstream_extras constructors for memory streams
- transitional/legacy constructors but not used in any code
- nonBlocking: receive before send
- nonBlocking: wait for receive requests, process and then wait for
other requests. Can be extended to use polling...
- the 'fake' send (to self) now send copies into recv buffers instead
of send buffers.
This provides a clear separation of send and receive fields
- avoid unnecessary reallocations with PtrList of send/recv buffers
- remove outer looping for accessAndFlip and pass target field
as parameter for inner looping instead
ENH: refine mapDistribute send/recv requests handling
- separate send/recv requests for finer control
- receive does not need access to PtrList of sendBuffers, since the
send-to-self now uses the recvBuffers
- totalSize() returns retrieve the linear (total) size
(naming as per globalIndex)
- operator[] retrieves the referenced value (linear indexing)
- labels() returns a flattened labelList (as per labelRange itself)
