Because it's possible for the data within a Buffer instance to be
altered after instantiation, or in case a user attempts to do something
like the following:
Buffer.prototype.fill.call({}, 10, 0, 10);
It doesn't result in a segfault.
This commit makes it possible to use multiple V8 execution contexts
within a single event loop. Put another way, handle and request wrap
objects now "remember" the context they belong to and switch back to
that context when the time comes to call into JS land.
This could have been done in a quick and hacky way by calling
v8::Object::GetCreationContext() on the wrap object right before
making a callback but that leaves a fairly wide margin for bugs.
Instead, we make the context explicit through a new Environment class
that encapsulates everything (or almost everything) that belongs to
the context. Variables that used to be a static or a global are now
members of the aforementioned class. An additional benefit is that
this approach should make it relatively straightforward to add full
isolate support in due course.
There is no JavaScript API yet but that will be added in the near
future.
This work was graciously sponsored by GitHub, Inc.
Due to a lot of the util.is* checks there was much unnecessary overhead
for the most common use case of Buffer. Which is creating a new Buffer
instance for data from incoming I/O. NativeBuffer is a simple way to
bypass all the unneeded checks and simply hand back a Buffer instance
while setting the length.
* Change calls to String::New() and String::NewSymbol() to their
respective one-byte, two-byte and UTF-8 counterparts.
* Add a FIXED_ONE_BYTE_STRING macro that takes a string literal and
turns it into a v8::Local<v8::String>.
* Add helper functions that make v8::String::NewFromOneByte() easier to
work with. Said function expects a `const uint8_t*` but almost every
call site deals with `const char*` or `const unsigned char*`. Helps
us avoid doing reinterpret_casts all over the place.
* Code that handles file system paths keeps using UTF-8 for backwards
compatibility reasons. At least now the use of UTF-8 is explicit.
* Remove v8::String::NewSymbol() entirely. Almost all call sites were
effectively minor de-optimizations. If you create a string only once,
there is no point in making it a symbol. If you are create the same
string repeatedly, it should probably be cached in a persistent
handle.
This is a big commit that touches just about every file in the src/
directory. The V8 API has changed in significant ways. The most
important changes are:
* Binding functions take a const v8::FunctionCallbackInfo<T>& argument
rather than a const v8::Arguments& argument.
* Binding functions return void rather than v8::Handle<v8::Value>. The
return value is returned with the args.GetReturnValue().Set() family
of functions.
* v8::Persistent<T> no longer derives from v8::Handle<T> and no longer
allows you to directly dereference the object that the persistent
handle points to. This means that the common pattern of caching
oft-used JS values in a persistent handle no longer quite works,
you first need to reconstruct a v8::Local<T> from the persistent
handle with the Local<T>::New(isolate, persistent) factory method.
A handful of (internal) convenience classes and functions have been
added to make dealing with the new API a little easier.
The most visible one is node::Cached<T>, which wraps a v8::Persistent<T>
with some template sugar. It can hold arbitrary types but so far it's
exclusively used for v8::Strings (which was by far the most commonly
cached handle type.)
gcc 4.2 on OS X gets confused about the call to node::Buffer::Data().
Fully qualify the function name to help it along.
Fixes the following build error:
../../deps/v8/include/v8.h: In function ‘char*
node::Buffer::Data(v8::Handle<v8::Value>)’:
../../deps/v8/include/v8.h:900: error: ‘class v8::Data’
is not a function,
../../src/node_buffer.h:38: error:
conflict with ‘char* node::Buffer::Data(v8::Handle<v8::Object>)’
../../src/node_buffer.cc:94: error:
in call to ‘Data’
Buffer(<String>) used to pass the string to js where it would then be
passed back to cpp for processing. Now only the buffer object
instantiation is done in js and the string is processed in cpp.
Also added a Buffer api that also accepts the encoding.
Old fill would take the char code of the first character and wrap around
the int to fit in the 127 range. Now fill will duplicate whatever string
is given through the entirety of the buffer.
Note: There is one bug around ending on a partial fill of any character
outside the ASCII range.
Memory allocations are now done through smalloc. The Buffer cc class has
been removed completely, but for backwards compatibility have left the
namespace as Buffer.
The .parent attribute is only set if the Buffer is a slice of an
allocation. Which is then set to the alloc object (not a Buffer).
The .offset attribute is now a ReadOnly set to 0, for backwards
compatibility. I'd like to remove it in the future (pre v1.0).
A few alterations have been made to how arguments are either coerced or
thrown. All primitives will now be coerced to their respective values,
and (most) all out of range index requests will throw.
The indexes that are coerced were left for backwards compatibility. For
example: Buffer slice operates more like Array slice, and coerces
instead of throwing out of range indexes. This may change in the future.
The reason for wanting to throw for out of range indexes is because
giving js access to raw memory has high potential risk. To mitigate that
it's easier to make sure the developer is always quickly alerted to the
fact that their code is attempting to access beyond memory bounds.
Because SlowBuffer will be deprecated, and simply returns a new Buffer
instance, all tests on SlowBuffer have been removed.
Heapdumps will now show usage under "smalloc" instead of "Buffer".
ParseArrayIndex was added to node_internals to support proper uint
argument checking/coercion for external array data indexes.
SlabAllocator had to be updated since handle_ no longer exists.
This also templatizes the Buffer::*Slice functions, and the template
function probably cannot be safely used outside of Node. However, it
also SHOULD not be used outside of Node, so this is arguably a feature
as well as a caveat.
_charsWritten is an internal property that was constantly written to,
but never read from. So it has been removed.
Removed documentation reference as well.
All compile time warnings about using deprecated APIs have been
suppressed by updating node's API. Though there are still many function
calls that can accept Isolate, and still need to be updated.
node_isolate had to be added as an extern variable in node.h and
node_object_wrap.h
Also a couple small fixes for Error handling.
Before v8 3.16.6 the error stack message was lazily written when it was
needed, which allowed you to change the message after instantiation.
Then the stack would be written with the new message the first time it
was accessed. Though that has changed. Now it creates the stack message
on instantiation. So setting a different message afterwards won't be
displayed.
This is not a complete fix for the problem. Getting error without any
message isn't very useful.
Consider the following example:
console.log(Buffer('ú').toString('ascii'));
Before this commit, the contents of the buffer was used as-is and hence it
prints 'ú'.
Now, it prints 'C:'. Perhaps not much of an improvement but it conforms to what
the documentation says it does: strip off the high bits.
Fixes#4371.
Move the implementation to C++ land. This is similar to commit 3f65916
but this time for the write() function and the Buffer(s, 'hex')
constructor.
Speeds up the benchmark below about 24x (2.6s vs 1:02m).
var s = 'f';
for (var i = 0; i < 26; ++i) s += s; // 64 MB
Buffer(s, 'hex');
Move the implementation to C++ land. The old JS implementation used
string concatenation, was dog slow and consumed copious amounts of
memory for large buffers. Example:
var buf = Buffer(0x1000000); // 16 MB
buf.toString('hex') // Used 3+ GB of memory.
The new implementation operates in O(n) time and space.
Fixes#4700.
If the end argument is omitted or not a number, make it default to
the end of the buffer, not zero.
Ideally, it should not matter what it defaults to because the JS shim
in lib/buffer.js should handle that but there are still several places
in node.js core that secrete SlowBuffers, hence Buffer::Copy() gets
called without going through Buffer.prototype.copy() first.
* Omit ToObject() call. Buffer::Data() and Buffer::Length() know how
to deal with Values.
* Don't check if the argument is undefined because it realistically
never is and undefined->integer coercion achieves the same thing.
Fix issue where SlowBuffers couldn't be passed as target to Buffer
copy().
Also included checks to see if Argument parameters are defined before
assigning their values. This offered ~3x's performance gain.
Backport of 16bbecc from master branch. Closes#4633.
Changed types of errors thrown to be more indicative of what the error
represents. Also removed a few unnecessary uses of the v8 fully
quantified typename.
Fix issue where SlowBuffers couldn't be passed as target to Buffer
copy().
Also included checks to see if Argument parameters are defined before
assigning their values. This offered ~3x's performance gain.
Removed range checks when writing float values, and removed a few
includes and defines. Also updated api docs to reflect that invalid 32
bit float is an unspecified behavior.
Reject negative offsets in SlowBuffer::MakeFastBuffer(), it allows
the creation of buffers that point to arbitrary addresses.
Reported by Trevor Norris.
Improvements:
* floating point operations are approx 4x's faster
* Now write quiet NaN's
* all read/write on floating point now done in C, so no more need for
lib/buffer_ieee754.js
* float values have more accurate min/max value checks
* add additional benchmarks for buffers read/write
* created benchmark/_bench_timer.js which is a simple library that
can be included into any benchmark and provides an intelligent tracker
for sync and async tests
* add benchmarks for DataView set methods
* add checks and tests to make sure offset is greater than 0
Remove a lot of branches from the inner loop. Speeds up buf.toString('base64')
by about 20%.
Before:
$ time out/Release/node benchmark/buffer-base64-encode.js
real 0m6.607s
user 0m5.508s
sys 0m1.088s
After:
$ time out/Release/node benchmark/buffer-base64-encode.js
real 0m5.520s
user 0m4.520s
sys 0m0.992s
Fedor Indutny
Trevor Norris
Ben Noordhuis
Timothy J Fontaine
isaacs