Prepare wpiutil for merge into allwpilib.

wpiutil/src/main/native/cpp/support/raw_istream.cpp

@@ -0,0 +1,134 @@
+/*----------------------------------------------------------------------------*/
+/* Copyright (c) 2015-2018 FIRST. 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.                                                               */
+/*----------------------------------------------------------------------------*/
+
+#include "support/raw_istream.h"
+
+#ifdef _WIN32
+#include <io.h>
+#else
+#include <unistd.h>
+#endif
+
+#include <cstdlib>
+#include <cstring>
+
+#include "llvm/FileSystem.h"
+#include "llvm/SmallVector.h"
+#include "llvm/StringRef.h"
+
+#if defined(_MSC_VER)
+#ifndef STDIN_FILENO
+#define STDIN_FILENO 0
+#endif
+#ifndef STDOUT_FILENO
+#define STDOUT_FILENO 1
+#endif
+#ifndef STDERR_FILENO
+#define STDERR_FILENO 2
+#endif
+#endif
+
+using namespace wpi;
+
+llvm::StringRef raw_istream::getline(llvm::SmallVectorImpl<char>& buf,
+                                     int maxLen) {
+  buf.clear();
+  for (int i = 0; i < maxLen; ++i) {
+    char c;
+    read(c);
+    if (has_error()) return llvm::StringRef{buf.data(), buf.size()};
+    if (c == '\r') continue;
+    buf.push_back(c);
+    if (c == '\n') break;
+  }
+  return llvm::StringRef{buf.data(), buf.size()};
+}
+
+raw_mem_istream::raw_mem_istream(llvm::StringRef mem)
+    : raw_mem_istream(mem.data(), mem.size()) {}
+
+void raw_mem_istream::close() {}
+
+size_t raw_mem_istream::in_avail() const { return m_left; }
+
+void raw_mem_istream::read_impl(void* data, size_t len) {
+  if (len > m_left) {
+    error_detected();
+    return;
+  }
+  std::memcpy(data, m_cur, len);
+  m_cur += len;
+  m_left -= len;
+}
+
+static int getFD(const llvm::Twine& Filename, std::error_code& EC) {
+  // Handle "-" as stdin. Note that when we do this, we consider ourself
+  // the owner of stdin. This means that we can do things like close the
+  // file descriptor when we're done and set the "binary" flag globally.
+  if (Filename.isSingleStringRef() && Filename.getSingleStringRef() == "-") {
+    EC = std::error_code();
+    return STDIN_FILENO;
+  }
+
+  int FD;
+
+  EC = llvm::sys::fs::openFileForRead(Filename, FD);
+  if (EC) return -1;
+
+  EC = std::error_code();
+  return FD;
+}
+
+raw_fd_istream::raw_fd_istream(const llvm::Twine& filename, std::error_code& ec,
+                               size_t bufSize)
+    : raw_fd_istream(getFD(filename, ec), true, bufSize) {}
+
+raw_fd_istream::raw_fd_istream(int fd, bool shouldClose, size_t bufSize)
+    : m_bufSize(bufSize), m_fd(fd), m_shouldClose(shouldClose) {
+  m_cur = m_end = m_buf = static_cast<char*>(std::malloc(bufSize));
+}
+
+raw_fd_istream::~raw_fd_istream() {
+  if (m_shouldClose) close();
+  std::free(m_buf);
+}
+
+void raw_fd_istream::close() {
+  if (m_fd >= 0) {
+    ::close(m_fd);
+    m_fd = -1;
+  }
+}
+
+size_t raw_fd_istream::in_avail() const { return m_end - m_cur; }
+
+void raw_fd_istream::read_impl(void* data, size_t len) {
+  size_t left = m_end - m_cur;
+  if (left < len) {
+    // not enough data
+    if (m_cur == m_end) {
+#ifdef _WIN32
+      int count = ::_read(m_fd, m_buf, m_bufSize);
+#else
+      ssize_t count = ::read(m_fd, m_buf, m_bufSize);
+#endif
+      if (count <= 0) {
+        error_detected();
+        return;
+      }
+      m_cur = m_buf;
+      m_end = m_buf + count;
+      return read_impl(data, len);
+    }
+
+    std::memcpy(data, m_cur, left);
+    return read_impl(static_cast<char*>(data) + left, len - left);
+  }
+
+  std::memcpy(data, m_cur, len);
+  m_cur += len;
+}