Instead of functions with different names (e.g. decode_utf8_block), split
utf_decoder class into multiple classes with ::process static function.
This makes it easier to share code for decoding different encodings.
Instead of calling xml_document public functions just call implementation of
load_buffer_inplace_own. This makes it so we only call reset() once during
load_file/load.
This makes conversion significantly faster and removes more CRT dependencies;
in particular, to support long long pugixml only requires the type itself (and
the division operator...).
New implementation is up to 3x faster on short decimal numbers.
Note that unlike the old implementation, new implementation correctly handles
overflow and underflow and clamps the value to the representable range. This
means that there are some behavior changes - e.g. previously as_uint on "-1"
would return INT_MAX instead of 0.
In addition to CRT issues, for platforms with 64-bit long old implementation
incorrectly truncated from long to int or unsigned int, so even if CRT clamped
the values the result would have been incorrect.
This reduces the amount of non-standard C++ functionality pugixml may be using
by avoiding sprintf with %lld; additionally this implementation is significantly
faster (4-5x) than sprintf, mostly due to avoiding format string parsing and
stream setup that commonly happens in CRT implementations.
This comes at the expense of requiring long long division/remainder operations
if PUGIXML_USE_LONG_LONG is defined which will surely bite me one day.
Change the expression to reference the array element indirectly. The memory
block can be bigger than the structure so it's invalid to use static data[]
size for bounds checking.
To be more precise, the memory block is now aligned to be able to reliably
allocate objects with both double and pointer fields. If there is a platform
with a 4-byte double and a 4-byte pointer, the memory block alignment there will
stay the same after this change.
Fixes#48.
Apparently Clang 3.7 implements C++ DR 1748 that makes placement new with null
pointer undefined behavior. Which renders all C++ programs that rely on this
invalid. Which includes pugixml.
This is not very likely to happen in the wild because the allocations that are
subject to this in pugixml are relatively small, but tests break because of
this.
Fix the issue by adding null pointer checks (that are completely redundant in
all current compilers except Clang 3.7 but it's not like there is another
option).
Work around a name lookup bug by pulling auto_deleter name in the local
scope. We could also move auto_deleter to pugi:: namespace, but that
pollutes it unnecessarily for other compilers.
Extra argument 'hint' is used to start the attribute lookup; if the attribute
is not found the lookup is restarted from the beginning of the attriubte list.
This allows to optimize attribute lookups if you need to get many attributes
from the node and can make assumptions about the likely ordering. The code is
correct regardless of the order, but it is faster than using vanilla lookups
if the order matches the calling order.
Fixes#30.
Now compact_string matches compact_pointer_parent.
Turns out PUGI__UNLIKELY is good at reordering conditions but usually does not
really affect performance. Since MSVC should treat "if" branches as taken and
does not support branch probabilities, don't use them if we don't need to.
Instead of checking if the object being removed allocated a marker, mark the
marker block as deleted immediately upon allocation. This simplifies the logic
and prevents extra markers from being inserted if we allocate/deallocate the
same node indefinitely.
Also change marker pointer type to uint32_t*.
When we deallocate nodes/attributes that allocated the marker we have to
adjust the size accordingly, and dismiss the marker in case it gets
overwritten with something else...
This temporarily increases the node size to 16 bytes - we'll bring it back.
It allows us to remove the horrible node_pi hack and to reduce the amount of
changes against master. This comes at the price of not decreasing basline
xml_node_struct size.
The compact xml_node_struct is also increased by this change but a followup
change will reduce *both* xml_attribute_struct and xml_node_struct (to 8/12
bytes).
We used this in two cases - to get the page pointer and to test flags.
We now use PUGI__GETPAGE for getting the page pointer and operator& to test
flags - this makes getting node type significantly faster since it does not
require page pointer reconstruction.
Clarify the offset applied when encoding the pointer difference.
Make decoding diff slightly more clear - no effect on performance.
Adjust branch weighting in compact_string encoding - 0.5% faster.
Use uint16_t in compact_pointer_parent - 2% faster.
Make sure compact_hash_table::rehash() is not inlined - that way reserve() is
inlined so the fast path has no extra function calls.
Also use subtraction instead of multiplication when checking capacity.
xpath_query, xpath_node_set and xpath_variable_set are now moveable.
This is a nice performance optimization for variable/node sets, and enables
storing xpath_query in containers without using pointers (it's only possible
now since the query is not copyable).
xpath_variable_set is essentially an associative container; it's about time it
became copyable.
Implementation is slightly tricky due to out of memory handling. Both copy ctor
and assignment operator have strong exception guarantee (even if exceptions are
disabled! which translates to "roll back on allocation errors").
