Empty string is extremely common and we can avoid a lot of heap churn
by simply caching one in the VM. Primitive strings are immutable anyway
so there is no observable behavior change outside of fewer collections.
Two things I hate about C++:
1. 'int', 'signed int' and 'unsigned int' are two distinct types while
'char, 'signed char' and 'unsigned char' are *three* distinct types.
This is because 'signed int' is an alias for 'int' but 'signed char'
can't be an alias for 'char' because on some weird systems 'char' is
unsigned.
One might think why not do it the other way around, make 'int' an
alias for 'signed int' and 'char' an alias for whatever that is on
the platform, or make 'char' signed on all platforms. But who am I
to ask?
2. 'unsigned long' and 'unsigned long long' are always different types,
even if both are 64 bit numbers.
This commit fixes a few bugs that coming from this.
See Also: 1b3169f405.
This function is not avaliable in the kernel.
In the future it would be nice to have some sort of <charconv> header
that does this for all integer types and then call it in strtoull and et
cetera.
The difference would be that this function say 'from_chars' would return
an Optional and not just interpret anything invalid as zero.
CppAutoComplete gets a string of code and a position within it, and
returns a Vector of auto-complete suggestions that are relevant for the
given position.
Currently, it's very naive - it uses our CppLexer to find identifiers
in the code which the auto-complete target is a prefix of.
To make it a little clearer what this is for. (This is an RAII helper
class for adding and removing an Interpreter to a VM's list of the
currently active (executing code) Interpreters.)
There are three classes avaliable that share the functionality of
BufferStream:
1. InputMemoryStream is for reading from static buffers. Example:
Bytes input = /* ... */;
InputMemoryStream stream { input };
LittleEndian<u32> little_endian_value;
input >> little_endian_value;
u32 host_endian_value;
input >> host_endian_value;
SomeComplexStruct complex_struct;
input >> Bytes { &complex_struct, sizeof(complex_struct) };
2. OutputMemoryStream is for writing to static buffers. Example:
Array<u8, 4096> buffer;
OutputMemoryStream stream;
stream << LittleEndian<u32> { 42 };
stream << ReadonlyBytes { &complex_struct, sizeof(complex_struct) };
foo(stream.bytes());
3. DuplexMemoryStream for writing to dynamic buffers, can also be used
as an intermediate buffer by reading from it directly. Example:
DuplexMemoryStream stream;
stream << NetworkOrdered<u32> { 13 };
stream << NetowkrOrdered<u64> { 22 };
NetworkOrdered<u32> value;
stream >> value;
ASSERT(value == 13);
foo(stream.copy_into_contiguous_buffer());
Unlike BufferStream these streams do not use a fixed endianness
(BufferStream used little endian) these have to be explicitly specified.
There are helper types in <AK/Endian.h>.
I could not test these changes because I could not get my telnet client
(on Linux) to connect to the telnet server running in Serenity.
I tried the follwing:
# Serenity
su
TelnetServer
# Linux
telnet localhost 8823
The server then immediatelly closes the connection:
Connection closed by foreign host.
In the debug logs the following message appears:
[NetworkTask(5:5)]: handle_tcp: unexpected flags in FinWait2 state
[NetworkTask(5:5)]: handle_tcp: unexpected flags in Closed state
[NetworkTask(5:5)]: handle_tcp: unexpected flags in Closed state
This seems to be an unrelated bug in the TCP implementation.
Since TCP sequence numbers are randomly choosen 32-bit numbers, it often
happend that the most significant bit was set. The cast to a 32-bit
signed integer then made the number negative.
Thus TCP sequence were shown negative in the SystemMonitor every so
often.
