| commit | 39f46faa69614b429b97bdad737097fa0497b06d | [log] [tgz] |
|---|---|---|
| author | Abseil Team <absl-team@google.com> | Tue Nov 09 10:34:06 2021 -0800 |
| committer | rogeeff <rogeeff@google.com> | Tue Nov 09 14:31:15 2021 -0500 |
| tree | 67355917455c818bcadebd60eb3611c0d77ea241 | |
| parent | c86347d4cec43074e64e225a8753728f4bfc5ed6 [diff] |
Export of internal Abseil changes -- 83e4cdf03a4d702b30e69204060de09e462e23c6 by Greg Falcon <gfalcon@google.com>: Revert the crc addition to RefcountAndFlags, and restore related comments to their original state. In development, the implementation of SetExpectedCrc() changed, and there is no longer a need to track the CRC status in the refcount. Since the distinction between IsOne() and IsMutable() is subtle *and unused*, removing it now can help avoid subtle bugs in the future. This distinction can always be added back later, if it proves necessary. Keep the reserved bit for now; all it costs is one extra mask instruction in the refcount checks, and space for extra state in Cord is always hard to find. PiperOrigin-RevId: 408647038 -- ee67585cf66954176615271f50f8b278119dd138 by Greg Falcon <gfalcon@google.com>: Implement Cord::SetExpectedChecksum() and Cord::ExpectedChecksum(). SetExpectedChecksum() will store a uint32_t out-of-band alongside a Cord's data. This value persists through copies and assignments. Mutating operations on a Cord cause the value to be forgotten. ExpectedChecksum() retrieves the stored value, if present. This API is intended for storing a CRC32C checksum alongside data, allowing checksums to be passed through dataflows and validated at the final step. However, this API is agnostic to the meaning of the stored value. No CRC32C validation is performed by these new APIs. This implementation adds a new CordRep node, CordRepCrc. A CordRepCrc may (currently) only live at the top of a tree. This allows traversal logic to be agnostic to these nodes, instead putting the needed branches at the mutation level. This also implements the property requested from API review, that any mutation is guaranteed to permanently forget the stored CRC. PiperOrigin-RevId: 408611221 -- a86f592402b37c854ebdc77d2b9b425451a7a675 by Martijn Vels <mvels@google.com>: Move 'ExtractResult' into CordRep The result of an extract operation is logically identical for any tree implementation, and having a single type makes 'tree independent' implementation in cord.cc more concise. PiperOrigin-RevId: 408332408 -- baa7647e21db59a87f75af9cac62172ce38a0f71 by Abseil Team <absl-team@google.com>: Replace usages of `assert` macros with `ABSL_HARDENING_ASSERT`. PiperOrigin-RevId: 408272133 -- c7658133d8662c39fa5035fc93a364c7c3d327e0 by Martijn Vels <mvels@google.com>: Add CordRepBtree::ExtractAppendBuffer PiperOrigin-RevId: 407944179 -- 5775100363b5890ebfe710fadebf040445eab991 by Martijn Vels <mvels@google.com>: Add CordRepConcat::ExtractAppendBuffer PiperOrigin-RevId: 407932968 -- 9f520ba1600a93352c78f644a369c7c76195ee86 by Greg Falcon <gfalcon@google.com>: Add cordz tracking for crc nodes. This also adds a new kSetExpectedChecksum method to the list of tracked methods. This is presently unused but will be used soon. PiperOrigin-RevId: 407884120 GitOrigin-RevId: 83e4cdf03a4d702b30e69204060de09e462e23c6 Change-Id: I134ace2d87215813eaa60a282996a33884676c06
The repository contains the Abseil C++ library code. Abseil is an open-source collection of C++ code (compliant to C++11) designed to augment the C++ standard library.
Abseil is an open-source collection of C++ library code designed to augment the C++ standard library. The Abseil library code is collected from Google's own C++ code base, has been extensively tested and used in production, and is the same code we depend on in our daily coding lives.
In some cases, Abseil provides pieces missing from the C++ standard; in others, Abseil provides alternatives to the standard for special needs we've found through usage in the Google code base. We denote those cases clearly within the library code we provide you.
Abseil is not meant to be a competitor to the standard library; we've just found that many of these utilities serve a purpose within our code base, and we now want to provide those resources to the C++ community as a whole.
If you want to just get started, make sure you at least run through the Abseil Quickstart. The Quickstart contains information about setting up your development environment, downloading the Abseil code, running tests, and getting a simple binary working.
Bazel and CMake are the official build systems for Abseil.
See the quickstart for more information on building Abseil using the Bazel build system.
If you require CMake support, please check the CMake build instructions and CMake Quickstart.
Abseil is officially supported on many platforms. See the Abseil platform support guide for details on supported operating systems, compilers, CPUs, etc.
Abseil contains the following C++ library components:
base Abseil Fundamentals base library contains initialization code and other code which all other Abseil code depends on. Code within base may not depend on any other code (other than the C++ standard library).algorithm algorithm library contains additions to the C++ <algorithm> library and container-based versions of such algorithms.cleanup cleanup library contains the control-flow-construct-like type absl::Cleanup which is used for executing a callback on scope exit.container container library contains additional STL-style containers, including Abseil's unordered “Swiss table” containers.debugging debugging library contains code useful for enabling leak checks, and stacktrace and symbolization utilities.hash hash library contains the hashing framework and default hash functor implementations for hashable types in Abseil.memory memory library contains C++11-compatible versions of std::make_unique() and related memory management facilities.meta meta library contains C++11-compatible versions of type checks available within C++14 and C++17 versions of the C++ <type_traits> library.numeric numeric library contains C++11-compatible 128-bit integers.profiling profiling library contains utility code for profiling C++ entities. It is currently a private dependency of other Abseil libraries.status status contains abstractions for error handling, specifically absl::Status and absl::StatusOr<T>.strings strings library contains a variety of strings routines and utilities, including a C++11-compatible version of the C++17 std::string_view type.synchronization synchronization library contains concurrency primitives (Abseil's absl::Mutex class, an alternative to std::mutex) and a variety of synchronization abstractions.time time library contains abstractions for computing with absolute points in time, durations of time, and formatting and parsing time within time zones.types types library contains non-container utility types, like a C++11-compatible version of the C++17 std::optional type.utility utility library contains utility and helper code.Abseil recommends users “live-at-head” (update to the latest commit from the master branch as often as possible). However, we realize this philosophy doesn't work for every project, so we also provide Long Term Support Releases to which we backport fixes for severe bugs. See our release management document for more details.
The Abseil C++ library is licensed under the terms of the Apache license. See LICENSE for more information.
For more information about Abseil: