Summary:
Returns number of bytes "really used by the user", i.e. number of bytes
allocated on the arena via calls to `allocate()`.

Test Plan: compiled, unit tests

Reviewed By: azzolini@fb.com

FB internal diff: D636976

Summary:
Supressing the warning for GCC4.7, and supressing the error supressing
the warning in GCC4.6.

Test Plan: Compile, run unit tests on GCC4.6 and GCC4.7

Reviewed By: ldbrandy@fb.com

FB internal diff: D635982

Summary:
Noticed these TODOs in Conv.h and decided to fix them.
Discovered that the underlying_type implementation also
covers enum classes, which didn't work with the pre-existing code.

Test Plan:
fbconfig -r folly --platform=gcc-4.7.1-glibc-2.14.1-fb
fbmake dbg _bin/folly/test/conv_test
_bin/folly/test/conv_test

--platform=gcc-4.6.2-glibc-2.13
fbmake dbg _bin/folly/test/conv_test
_bin/folly/test/conv_test

Reviewed By: tudorb@fb.com

FB internal diff: D634309

Summary: D633912 broke unicorn because it relied on preallocate having a hard max.  Add an optional hard max parameter and rename maxHint to newAllocationSize.  Pass the hard max in for unicorn

Test Plan: folly and unicorn unit tests

Reviewed By: tudorb@fb.com

FB internal diff: D634894

Summary: IOBufQueue::preallocate currently takes a min and max size, and will return to the caller a buffer with N writable bytes with min <= N <= max.  This is a bit wasteful, since there may be more than max bytes available at the end if the queue with no extra cost.  Now preallocate will return the full amount of contigious space to the caller, even if it is larger than the requested max.

Test Plan: folly and proxygen unit tests

Reviewed By: simpkins@fb.com

FB internal diff: D633912

Summary:
cursor.clone() will clone a length of the chain.  insert(std::move(buf)) will splice in a length of chain
I want this to change thrift2 binary type to IOBuf: we will clone() the network data for zero-copy userspace data, and insert() it if the return value is a IOBuf.

Test Plan: added unittest

Reviewed By: afrind@fb.com

FB internal diff: D632073

Summary:
Add a version of IOBuf::copyBuffer() which accepts a std::string, as
well as a maybeCopyBuffer() function which returns a null pointer if the
input string is empty.

In proxygen we have a few places where we construct an IOBuf from a
string configuration parameter, and we almost always want a null pointer
rather than an empty IOBuf chain if the string is empty.

Test Plan: Included unit tests for these new functions.

Reviewed By: tudorb@fb.com

FB internal diff: D630547

Summary: ##byLine## already yields StringPieces, no neat to ##eachAs()## then.

Test Plan:
fbconfig folly/experimental/symbolizer folly/test folly/experimental/io folly/experimental/io/test tupperware/agent
fbmake opt

Reviewed By: tudorb@fb.com

FB internal diff: D630422

Test Plan: build

Reviewed By: dneiter@fb.com

FB internal diff: D630324

Test Plan: build

Reviewed By: tjackson@fb.com

FB internal diff: D630280

Test Plan: test added

Reviewed By: tjackson@fb.com

FB internal diff: D630163

Test Plan: build

Reviewed By: tjackson@fb.com

FB internal diff: D630266

Summary:
Switch existing code to gen::byLine.  Also fix namespaces in
folly/experimental/(symbolizer|exception_tracer).

Test Plan:
fbconfig -r folly && fbmake runtests_opt, ran non-test folly
binaries by hand, fbgs for other uses (there aren't any)

Reviewed By: tjackson@fb.com

FB internal diff: D629576

Summary: Normal split to complement resplit, and it's a bit faster than folly::split().

Test Plan: Unit tests, Benchmarks (result in code comment)

Reviewed By: tudorb@fb.com

FB internal diff: D629998

Test Plan: no

Reviewed By: tjackson@fb.com

FB internal diff: D629502

Summary:
Also added eachAs (cast each value as a given type) and eachTo (use folly::to
on each value)

Test Plan: test added

Reviewed By: tjackson@fb.com

FB internal diff: D628868

Summary: Make things work with non-copyable generators.

Test Plan: folly/experimental/test

Reviewed By: tjackson@fb.com

FB internal diff: D628520

Summary:
Want to be able to call them from other constexpr functions
and from within static_assert()s.

Test Plan: compiled and ran folly tests

Reviewed By: tudorb@fb.com

FB internal diff: D627413

Summary: That's all.

Test Plan: .

Reviewed By: tjackson@fb.com

FB internal diff: D618824

Summary:
Sometimes it'll be handy to have a custom operator which is little more than the
composition of a few base operators. This makes that really easy to do, as shown
in examples, tests, and benchmarks.

Test Plan: Unit tests, benchmarks

Reviewed By: rsagula@fb.com

FB internal diff: D617152

Summary: We should be able to print ##Foo*##, even if we can't print ##Foo##.

Test Plan: Unit Tests.

Reviewed By: tudorb@fb.com

FB internal diff: D625977

Summary:
If your format string ends up being conditional, it's handy to be able to chain
together formatters.

Test Plan: Unit tests

Reviewed By: tudorb@fb.com

FB internal diff: D625502

Summary:
Convert a IOBuf chain into a fbstring, with zero copies in the common case
(unshared, unchained, no headroom) and one copy in all other cases.

Test Plan: tests added

Reviewed By: simpkins@fb.com

FB internal diff: D621210

Summary: fixing clang errors (used clang 3.1)

Test Plan: doh

Reviewed By: tudorb@fb.com

FB internal diff: D622593

Summary:
Yes, I admit, I was dumb enough to try it in a benchmark's
body.

Test Plan: review

Reviewed By: tudorb@fb.com

FB internal diff: D622613

Summary:
DynamicConverter uses some simple heuristics to determine if a
class is a container. One of those tests was to check that the
constructor 'template <class Iterator> [container-name](Iterator first,
Iterator last)' was present. That test was performed by checking if the
class could be constructed by two parameters of some dummy class.

However, it is possible to restrict the template parameter such that it
only accepts iterators, and not any arbitrary dummy class. This would be
useful, for example, to solve overload ambiguity with constructors like
'vector(const T& val, size_type n)', where T and size_type are the same
(see N3337 23.2.3 item 14). It also (I believe) produces more meaningful
compiler errors when a non-iterator is supplied, since it errors at the
function callsite instead of inside the constructor itself.

The new FBVector implementation uses such a feature, and so checking for
[container-name](dummy, dummy) will fail. Hence the dummy class has been
upgraded to reverse_iterator<T*>, a valid iterator class which almost
certainly does not have a specialized contructor in any class (and hence
will not cause any visible change in class_is_container's value).

Test Plan:
Run DynamicConverterTest; it has tests for the correctness of
class_is_container.

Reviewed By: delong.j@fb.com

FB internal diff: D620607

Summary:
Changed communicate() flags from int to a class.
Made Options and CommunicateFlags composable with |
Simplified API so you don't have to type Subprocess::Options().stdout(Subprocess::PIPE)

Test Plan: subprocess_test

Reviewed By: chip@fb.com

FB internal diff: D620186

Test Plan: subprocess_test

Reviewed By: delong.j@fb.com

FB internal diff: D619713

Test Plan: subprocess_test

Reviewed By: chip@fb.com

FB internal diff: D619189

Summary:
Surprised we don't have one.  The API is modeled after Python's
subprocess module, http://docs.python.org/2/library/subprocess.html

Inspired by
https://www.facebook.com/groups/fbcode/permalink/445399858830192/, plus
I needed this functionality now.

Test Plan: test added

Reviewed By: chip@fb.com

FB internal diff: D614056

Summary: parseInt128 is only available for GCC 4.7 and above.

Test Plan: .

Reviewed By: igorzi@fb.com

FB internal diff: D618456

Blame Revision: rFBCODEeaec97e2991f

Summary:
Add benchmarks for throwing an exception versus returning
std::exception_ptr or other types of return values.

Throwing an exception is very expensive.  Calling std::make_exception_ptr()
without ever throwing is nearly as bad.

The exc_ptr_param_return tests were the ones I was most interested in.
(Accepting a std::exception_ptr* argument so the caller can indicate if they
want to receive an exception or not.)  This is fast if the caller doesn't care
about the exception value, but very slow if an error occurs and an
exception_ptr is required.

Test Plan:
======================================================================
folly/test/function_benchmark/main.cpp    relative  time/iter  iters/s
======================================================================
throw_exception                                        3.90us  256.25K
catch_no_exception                                     1.88ns  533.25M
return_exc_ptr                                         2.79us  357.85K
exc_ptr_param_return                                   2.83us  353.25K
exc_ptr_param_return_null                              2.25ns  444.38M
return_string                                         69.39ns   14.41M
return_string_noexcept                                69.39ns   14.41M
return_code                                            1.50ns  666.54M
return_code_noexcept                                   1.50ns  666.54M

Reviewed By: rajat@fb.com

FB internal diff: D616474

Summary: Just that.

Test Plan: .

Reviewed By: igorzi@fb.com

FB internal diff: D613291

Summary:
folly::toJson as demonstrated by the test cases was wrongly encoding utf8 strings.
specifically, a utf8 char made up of x bytes was encodeded into x unicode chars.

for example, the char:
\u2665
which is made of 3 bytes:
\xe2\x99\xa5
was encoded correctly when using encode_non_ascii = true:
"\u2665"
but when encode_non_ascii = false, the json value was wrongly set as:
"\u00e2\u0099\u00a5"

because we use an signed char that wrongly detects non-readable chars with
ascii value > 127 as control chars with ascii value < 32 (\t, \n, etc.)

Test Plan: run the test

Reviewed By: delong.j@fb.com

FB internal diff: D612782

Summary: Tests were run in 'opt', which masked issues alterted by asserts.

Test Plan: Unit tests

Reviewed By: delong.j@fb.com

FB internal diff: D611957

Summary:
the currently code calls both ~SkipListNode() and node->data_.~value_type()
causes double destructing the object.

Test Plan: adding dihde's testing code to a test case

Reviewed By: emailweixu@fb.com

FB internal diff: D612289

Summary: fix Benchmark docs

Test Plan: read

Reviewed By: andrei.alexandrescu@fb.com

FB internal diff: D611820

Summary:
Moving Comprehensions library into Folly and refactoring its interface to be much more modular and composable. There are now two core abstractions:

# Generators: Standalone classes supporting ##apply()## and optionally ##foreach()##. These all inherit from ##GenImpl<T, Self>##.
# Operators: Standalone classes which, when composed with a generator, produce a new generator. These all inherit from ##OperatorImpl<Self>##.

These generators may be composed with ##operator|## overloads which only match ##const GenImpl<T, Self>&## on the left like ##gen | op##.  Additionally, generator may be consumed inline with ##gen | lambda## like ##gen | [](int x) { cout << x << endl; };##.

With this design, new operators may be added very simply without modifying the core library and templates are instantiated only exactly as needed.

Example:

```lang=cpp
auto sum = seq(1, 10) | filter(isPrime) | sum;
seq(1, 10) | [](int i) {
cout << i << endl;
};
```

Test Plan: Unit tests

Reviewed By: andrei.alexandrescu@fb.com

FB internal diff: D542215

Summary: C++11 added front() and back() that return by reference. fbstring also added front() and back() as non-standard convenience functions, which returned by value. This diff aligns fbstring with the standard.

Test Plan: added and ran unittest

Reviewed By: delong.j@fb.com

FB internal diff: D607574

Summary: Optional, like boost::optional, but with full rvalue support.

Test Plan: Unit tests

Reviewed By: delong.j@fb.com

FB internal diff: D571810