Make many more utility classes/headers public. (#76)

Moving these headers from src to include enables other libraries to use the
functionality provided.

* tcpsockets
* atomic_static
* raw_istream
* timestamp
* SafeThread
* Base64
* LEB128
* ConcurrentQueue

The classes have been moved into the wpi namespace as they're generic.

include/support/Base64.h

@@ -0,0 +1,23 @@
+/*----------------------------------------------------------------------------*/
+/* Copyright (c) FIRST 2015. All Rights Reserved.                             */
+/* Open Source Software - may be modified and shared by FRC teams. The code   */
+/* must be accompanied by the FIRST BSD license file in the root directory of */
+/* the project.                                                               */
+/*----------------------------------------------------------------------------*/
+
+#ifndef WPIUTIL_SUPPORT_BASE64_H_
+#define WPIUTIL_SUPPORT_BASE64_H_
+
+#include <cstddef>
+#include <string>
+
+#include "llvm/StringRef.h"
+
+namespace wpi {
+
+std::size_t Base64Decode(llvm::StringRef encoded, std::string* plain);
+void Base64Encode(llvm::StringRef plain, std::string* encoded);
+
+}  // namespace wpi
+
+#endif  // WPIUTIL_SUPPORT_BASE64_H_

include/support/ConcurrentQueue.h

@@ -0,0 +1,83 @@
+//
+// Copyright (c) 2013 Juan Palacios juan.palacios.puyana@gmail.com
+// Subject to the BSD 2-Clause License
+// - see < http://opensource.org/licenses/BSD-2-Clause>
+//
+
+#ifndef WPIUTIL_SUPPORT_CONCURRENT_QUEUE_H_
+#define WPIUTIL_SUPPORT_CONCURRENT_QUEUE_H_
+
+#include <queue>
+#include <thread>
+#include <mutex>
+#include <condition_variable>
+
+namespace wpi {
+
+template <typename T>
+class ConcurrentQueue {
+ public:
+  bool empty() const {
+    std::unique_lock<std::mutex> mlock(mutex_);
+    return queue_.empty();
+  }
+
+  typename std::queue<T>::size_type size() const {
+    std::unique_lock<std::mutex> mlock(mutex_);
+    return queue_.size();
+  }
+
+  T pop() {
+    std::unique_lock<std::mutex> mlock(mutex_);
+    while (queue_.empty()) {
+      cond_.wait(mlock);
+    }
+    auto item = std::move(queue_.front());
+    queue_.pop();
+    return item;
+  }
+
+  void pop(T& item) {
+    std::unique_lock<std::mutex> mlock(mutex_);
+    while (queue_.empty()) {
+      cond_.wait(mlock);
+    }
+    item = queue_.front();
+    queue_.pop();
+  }
+
+  void push(const T& item) {
+    std::unique_lock<std::mutex> mlock(mutex_);
+    queue_.push(item);
+    mlock.unlock();
+    cond_.notify_one();
+  }
+
+  void push(T&& item) {
+    std::unique_lock<std::mutex> mlock(mutex_);
+    queue_.push(std::forward<T>(item));
+    mlock.unlock();
+    cond_.notify_one();
+  }
+
+  template <typename... Args>
+  void emplace(Args&&... args) {
+    std::unique_lock<std::mutex> mlock(mutex_);
+    queue_.emplace(std::forward<Args>(args)...);
+    mlock.unlock();
+    cond_.notify_one();
+  }
+
+  ConcurrentQueue() = default;
+  ConcurrentQueue(const ConcurrentQueue&) = delete;
+  ConcurrentQueue& operator=(const ConcurrentQueue&) = delete;
+
+ private:
+  std::queue<T> queue_;
+  mutable std::mutex mutex_;
+  std::condition_variable cond_;
+};
+
+}  // namespace wpi
+
+#endif  // WPIUTIL_SUPPORT_CONCURRENT_QUEUE_H_

include/support/Logger.h

@@ -0,0 +1,82 @@
+/*----------------------------------------------------------------------------*/
+/* Copyright (c) FIRST 2015. All Rights Reserved.                             */
+/* Open Source Software - may be modified and shared by FRC teams. The code   */
+/* must be accompanied by the FIRST BSD license file in the root directory of */
+/* the project.                                                               */
+/*----------------------------------------------------------------------------*/
+
+#ifndef WPIUTIL_SUPPORT_LOGGER_H_
+#define WPIUTIL_SUPPORT_LOGGER_H_
+
+#include <functional>
+#include <sstream>
+#include <string>
+
+namespace wpi {
+
+enum LogLevel {
+  WPI_LOG_CRITICAL = 50,
+  WPI_LOG_ERROR = 40,
+  WPI_LOG_WARNING = 30,
+  WPI_LOG_INFO = 20,
+  WPI_LOG_DEBUG = 10,
+  WPI_LOG_DEBUG1 = 9,
+  WPI_LOG_DEBUG2 = 8,
+  WPI_LOG_DEBUG3 = 7,
+  WPI_LOG_DEBUG4 = 6
+};
+
+class Logger {
+ public:
+  typedef std::function<void(unsigned int level, const char* file,
+                             unsigned int line, const char* msg)> LogFunc;
+
+  void SetLogger(LogFunc func) { m_func = func; }
+
+  void set_min_level(unsigned int level) { m_min_level = level; }
+  unsigned int min_level() const { return m_min_level; }
+
+  void Log(unsigned int level, const char* file, unsigned int line,
+           const char* msg) {
+    if (!m_func || level < m_min_level) return;
+    m_func(level, file, line, msg);
+  }
+
+  bool HasLogger() const { return m_func != nullptr; }
+
+ private:
+  LogFunc m_func;
+  unsigned int m_min_level = 20;
+};
+
+#define WPI_LOG(logger_inst, level, x)                                 \
+  do {                                                                 \
+    ::wpi::Logger& WPI_logger_ = logger_inst;                          \
+    if (WPI_logger_.min_level() <= level && WPI_logger_.HasLogger()) { \
+      std::ostringstream oss;                                          \
+      oss << x;                                                        \
+      WPI_logger_.Log(level, __FILE__, __LINE__, oss.str().c_str());   \
+    }                                                                  \
+  } while (0)
+
+#define WPI_ERROR(inst, x) WPI_LOG(inst, ::wpi::WPI_LOG_ERROR, x)
+#define WPI_WARNING(inst, x) WPI_LOG(inst, ::wpi::WPI_LOG_WARNING, x)
+#define WPI_INFO(inst, x) WPI_LOG(inst, ::wpi::WPI_LOG_INFO, x)
+
+#ifdef NDEBUG
+#define WPI_DEBUG(inst, x) do {} while (0)
+#define WPI_DEBUG1(inst, x) do {} while (0)
+#define WPI_DEBUG2(inst, x) do {} while (0)
+#define WPI_DEBUG3(inst, x) do {} while (0)
+#define WPI_DEBUG4(inst, x) do {} while (0)
+#else
+#define WPI_DEBUG(inst, x) WPI_LOG(inst, ::wpi::WPI_LOG_DEBUG, x)
+#define WPI_DEBUG1(inst, x) WPI_LOG(inst, ::wpi::WPI_LOG_DEBUG1, x)
+#define WPI_DEBUG2(inst, x) WPI_LOG(inst, ::wpi::WPI_LOG_DEBUG2, x)
+#define WPI_DEBUG3(inst, x) WPI_LOG(inst, ::wpi::WPI_LOG_DEBUG3, x)
+#define WPI_DEBUG4(inst, x) WPI_LOG(inst, ::wpi::WPI_LOG_DEBUG4, x)
+#endif
+
+} // namespace wpi
+
+#endif  // WPIUTIL_SUPPORT_LOGGER_H_

include/support/SafeThread.h

@@ -0,0 +1,93 @@
+/*----------------------------------------------------------------------------*/
+/* Copyright (c) FIRST 2015. All Rights Reserved.                             */
+/* Open Source Software - may be modified and shared by FRC teams. The code   */
+/* must be accompanied by the FIRST BSD license file in the root directory of */
+/* the project.                                                               */
+/*----------------------------------------------------------------------------*/
+
+#ifndef WPIUTIL_SUPPORT_SAFETHREAD_H_
+#define WPIUTIL_SUPPORT_SAFETHREAD_H_
+
+#include <atomic>
+#include <condition_variable>
+#include <mutex>
+#include <thread>
+
+namespace wpi {
+
+// Base class for SafeThreadOwner threads.
+class SafeThread {
+ public:
+  virtual ~SafeThread() = default;
+  virtual void Main() = 0;
+
+  std::mutex m_mutex;
+  bool m_active = true;
+  std::condition_variable m_cond;
+};
+
+namespace detail {
+
+// Non-template proxy base class for common proxy code.
+class SafeThreadProxyBase {
+ public:
+  SafeThreadProxyBase(SafeThread* thr) : m_thread(thr) {
+    if (!m_thread) return;
+    std::unique_lock<std::mutex>(m_thread->m_mutex).swap(m_lock);
+    if (!m_thread->m_active) {
+      m_lock.unlock();
+      m_thread = nullptr;
+      return;
+    }
+  }
+  explicit operator bool() const { return m_thread != nullptr; }
+  std::unique_lock<std::mutex>& GetLock() { return m_lock; }
+
+ protected:
+  SafeThread* m_thread;
+  std::unique_lock<std::mutex> m_lock;
+};
+
+// A proxy for SafeThread.
+// Also serves as a scoped lock on SafeThread::m_mutex.
+template <typename T>
+class SafeThreadProxy : public SafeThreadProxyBase {
+ public:
+  SafeThreadProxy(SafeThread* thr) : SafeThreadProxyBase(thr) {}
+  T& operator*() const { return *static_cast<T*>(m_thread); }
+  T* operator->() const { return static_cast<T*>(m_thread); }
+};
+
+// Non-template owner base class for common owner code.
+class SafeThreadOwnerBase {
+ public:
+  void Stop();
+
+ protected:
+  SafeThreadOwnerBase() { m_thread = nullptr; }
+  SafeThreadOwnerBase(const SafeThreadOwnerBase&) = delete;
+  SafeThreadOwnerBase& operator=(const SafeThreadOwnerBase&) = delete;
+  ~SafeThreadOwnerBase() { Stop(); }
+
+  void Start(SafeThread* thr);
+  SafeThread* GetThread() { return m_thread.load(); }
+
+ private:
+  std::atomic<SafeThread*> m_thread;
+};
+
+}  // namespace detail
+
+template <typename T>
+class SafeThreadOwner : public detail::SafeThreadOwnerBase {
+ public:
+  void Start() { Start(new T); }
+  void Start(T* thr) { detail::SafeThreadOwnerBase::Start(thr); }
+
+  using Proxy = typename detail::SafeThreadProxy<T>;
+  Proxy GetThread() { return Proxy(detail::SafeThreadOwnerBase::GetThread()); }
+};
+
+}  // namespace wpi
+
+#endif  // WPIUTIL_SUPPORT_SAFETHREAD_H_

include/support/atomic_static.h

@@ -0,0 +1,49 @@
+/*----------------------------------------------------------------------------*/
+/* Copyright (c) FIRST 2015. All Rights Reserved.                             */
+/* Open Source Software - may be modified and shared by FRC teams. The code   */
+/* must be accompanied by the FIRST BSD license file in the root directory of */
+/* the project.                                                               */
+/*----------------------------------------------------------------------------*/
+
+#ifndef WPIUTIL_SUPPORT_ATOMIC_STATIC_H_
+#define WPIUTIL_SUPPORT_ATOMIC_STATIC_H_
+
+#if !defined(_MSC_VER) || (_MSC_VER >= 1900)
+
+// Just use a local static.  This is thread-safe per
+// http://preshing.com/20130930/double-checked-locking-is-fixed-in-cpp11/
+
+// Per https://msdn.microsoft.com/en-us/library/Hh567368.aspx "Magic Statics"
+// are supported in Visual Studio 2015 but not in earlier versions.
+#define ATOMIC_STATIC(cls, inst) static cls inst
+#define ATOMIC_STATIC_DECL(cls)
+#define ATOMIC_STATIC_INIT(cls)
+
+#else
+// From http://preshing.com/20130930/double-checked-locking-is-fixed-in-cpp11/
+#include <atomic>
+#include <mutex>
+
+#define ATOMIC_STATIC(cls, inst) \
+    cls* inst##tmp = m_instance.load(std::memory_order_acquire); \
+    if (inst##tmp == nullptr) { \
+      std::lock_guard<std::mutex> lock(m_instance_mutex); \
+      inst##tmp = m_instance.load(std::memory_order_relaxed); \
+      if (inst##tmp == nullptr) { \
+        inst##tmp = new cls; \
+        m_instance.store(inst##tmp, std::memory_order_release); \
+      } \
+    } \
+    cls& inst = *inst##tmp
+
+#define ATOMIC_STATIC_DECL(cls) \
+    static std::atomic<cls*> m_instance; \
+    static std::mutex m_instance_mutex;
+
+#define ATOMIC_STATIC_INIT(cls) \
+    std::atomic<cls*> cls::m_instance; \
+    std::mutex cls::m_instance_mutex;
+
+#endif
+
+#endif  // WPIUTIL_SUPPORT_ATOMIC_STATIC_H_

include/support/leb128.h

@@ -0,0 +1,26 @@
+/*----------------------------------------------------------------------------*/
+/* Copyright (c) FIRST 2015. All Rights Reserved.                             */
+/* Open Source Software - may be modified and shared by FRC teams. The code   */
+/* must be accompanied by the FIRST BSD license file in the root directory of */
+/* the project.                                                               */
+/*----------------------------------------------------------------------------*/
+
+#ifndef WPIUTIL_SUPPORT_LEB128_H_
+#define WPIUTIL_SUPPORT_LEB128_H_
+
+#include <cstddef>
+
+#include "llvm/SmallVector.h"
+
+namespace wpi {
+
+class raw_istream;
+
+std::size_t SizeUleb128(unsigned long val);
+std::size_t WriteUleb128(llvm::SmallVectorImpl<char>& dest, unsigned long val);
+std::size_t ReadUleb128(const char* addr, unsigned long* ret);
+bool ReadUleb128(raw_istream& is, unsigned long* ret);
+
+}  // namespace wpi
+
+#endif  // WPIUTIL_SUPPORT_LEB128_H_

include/support/raw_istream.h

@@ -0,0 +1,40 @@
+/*----------------------------------------------------------------------------*/
+/* Copyright (c) FIRST 2015. All Rights Reserved.                             */
+/* Open Source Software - may be modified and shared by FRC teams. The code   */
+/* must be accompanied by the FIRST BSD license file in the root directory of */
+/* the project.                                                               */
+/*----------------------------------------------------------------------------*/
+
+#ifndef WPIUTIL_SUPPORT_RAW_ISTREAM_H_
+#define WPIUTIL_SUPPORT_RAW_ISTREAM_H_
+
+#include <cstddef>
+
+namespace wpi {
+
+class raw_istream {
+ public:
+  raw_istream() = default;
+  virtual ~raw_istream() = default;
+  virtual bool read(void* data, std::size_t len) = 0;
+  virtual void close() = 0;
+
+  raw_istream(const raw_istream&) = delete;
+  raw_istream& operator=(const raw_istream&) = delete;
+};
+
+class raw_mem_istream : public raw_istream {
+ public:
+  raw_mem_istream(const char* mem, std::size_t len) : m_cur(mem), m_left(len) {}
+  virtual ~raw_mem_istream() = default;
+  virtual bool read(void* data, std::size_t len);
+  virtual void close() {}
+
+ private:
+  const char* m_cur;
+  std::size_t m_left;
+};
+
+}  // namespace wpi
+
+#endif  // WPIUTIL_SUPPORT_RAW_ISTREAM_H_

include/support/raw_socket_istream.h

@@ -0,0 +1,31 @@
+/*----------------------------------------------------------------------------*/
+/* Copyright (c) FIRST 2015. All Rights Reserved.                             */
+/* Open Source Software - may be modified and shared by FRC teams. The code   */
+/* must be accompanied by the FIRST BSD license file in the root directory of */
+/* the project.                                                               */
+/*----------------------------------------------------------------------------*/
+
+#ifndef WPIUTIL_SUPPORT_RAW_SOCKET_ISTREAM_H_
+#define WPIUTIL_SUPPORT_RAW_SOCKET_ISTREAM_H_
+
+#include "support/raw_istream.h"
+#include "tcpsockets/NetworkStream.h"
+
+namespace wpi {
+
+class raw_socket_istream : public raw_istream {
+ public:
+  raw_socket_istream(NetworkStream& stream, int timeout = 0)
+      : m_stream(stream), m_timeout(timeout) {}
+  virtual ~raw_socket_istream() = default;
+  virtual bool read(void* data, std::size_t len);
+  virtual void close();
+
+ private:
+  NetworkStream& m_stream;
+  int m_timeout;
+};
+
+}  // namespace wpi
+
+#endif  // WPIUTIL_SUPPORT_RAW_SOCKET_ISTREAM_H_

include/support/timestamp.h

@@ -0,0 +1,28 @@
+/*----------------------------------------------------------------------------*/
+/* Copyright (c) FIRST 2015. All Rights Reserved.                             */
+/* Open Source Software - may be modified and shared by FRC teams. The code   */
+/* must be accompanied by the FIRST BSD license file in the root directory of */
+/* the project.                                                               */
+/*----------------------------------------------------------------------------*/
+#ifndef WPIUTIL_SUPPORT_TIMESTAMP_H_
+#define WPIUTIL_SUPPORT_TIMESTAMP_H_
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+unsigned long long WPI_Now(void);
+
+#ifdef __cplusplus
+}
+#endif
+
+#ifdef __cplusplus
+namespace wpi {
+
+unsigned long long Now();
+
+}  // namespace wpi
+#endif
+
+#endif  // WPIUTIL_SUPPORT_TIMESTAMP_H_