Initial checkin of gRPC to third_party/

third_party/grpc/src/core/support/time.c

Index: third_party/grpc/src/core/support/time.c
diff --git a/third_party/grpc/src/core/support/time.c b/third_party/grpc/src/core/support/time.c
new file mode 100644
index 0000000000000000000000000000000000000000..423d12ffc0fd052da61b22d1322ee9e54ca1d04b
--- /dev/null
+++ b/third_party/grpc/src/core/support/time.c
@@ -0,0 +1,304 @@
+/*
+ *
+ * Copyright 2015-2016, Google Inc.
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions are
+ * met:
+ *
+ *     * Redistributions of source code must retain the above copyright
+ * notice, this list of conditions and the following disclaimer.
+ *     * Redistributions in binary form must reproduce the above
+ * copyright notice, this list of conditions and the following disclaimer
+ * in the documentation and/or other materials provided with the
+ * distribution.
+ *     * Neither the name of Google Inc. nor the names of its
+ * contributors may be used to endorse or promote products derived from
+ * this software without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+ * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+ * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+ * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+ * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+ * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+ * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+ * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+ * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+ * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+ * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ *
+ */
+
+/* Generic implementation of time calls. */
+
+#include <grpc/support/time.h>
+#include <limits.h>
+#include <stdio.h>
+#include <string.h>
+#include <grpc/support/log.h>
+
+int gpr_time_cmp(gpr_timespec a, gpr_timespec b) {
+  int cmp = (a.tv_sec > b.tv_sec) - (a.tv_sec < b.tv_sec);
+  GPR_ASSERT(a.clock_type == b.clock_type);
+  if (cmp == 0) {
+    cmp = (a.tv_nsec > b.tv_nsec) - (a.tv_nsec < b.tv_nsec);
+  }
+  return cmp;
+}
+
+gpr_timespec gpr_time_min(gpr_timespec a, gpr_timespec b) {
+  return gpr_time_cmp(a, b) < 0 ? a : b;
+}
+
+gpr_timespec gpr_time_max(gpr_timespec a, gpr_timespec b) {
+  return gpr_time_cmp(a, b) > 0 ? a : b;
+}
+
+gpr_timespec gpr_time_0(gpr_clock_type type) {
+  gpr_timespec out;
+  out.tv_sec = 0;
+  out.tv_nsec = 0;
+  out.clock_type = type;
+  return out;
+}
+
+gpr_timespec gpr_inf_future(gpr_clock_type type) {
+  gpr_timespec out;
+  out.tv_sec = INT64_MAX;
+  out.tv_nsec = 0;
+  out.clock_type = type;
+  return out;
+}
+
+gpr_timespec gpr_inf_past(gpr_clock_type type) {
+  gpr_timespec out;
+  out.tv_sec = INT64_MIN;
+  out.tv_nsec = 0;
+  out.clock_type = type;
+  return out;
+}
+
+/* TODO(ctiller): consider merging _nanos, _micros, _millis into a single
+   function for maintainability. Similarly for _seconds, _minutes, and _hours */
+
+gpr_timespec gpr_time_from_nanos(int64_t ns, gpr_clock_type type) {
+  gpr_timespec result;
+  result.clock_type = type;
+  if (ns == INT64_MAX) {
+    result = gpr_inf_future(type);
+  } else if (ns == INT64_MIN) {
+    result = gpr_inf_past(type);
+  } else if (ns >= 0) {
+    result.tv_sec = ns / GPR_NS_PER_SEC;
+    result.tv_nsec = (int32_t)(ns - result.tv_sec * GPR_NS_PER_SEC);
+  } else {
+    /* Calculation carefully formulated to avoid any possible under/overflow. */
+    result.tv_sec = (-(999999999 - (ns + GPR_NS_PER_SEC)) / GPR_NS_PER_SEC) - 1;
+    result.tv_nsec = (int32_t)(ns - result.tv_sec * GPR_NS_PER_SEC);
+  }
+  return result;
+}
+
+gpr_timespec gpr_time_from_micros(int64_t us, gpr_clock_type type) {
+  gpr_timespec result;
+  result.clock_type = type;
+  if (us == INT64_MAX) {
+    result = gpr_inf_future(type);
+  } else if (us == INT64_MIN) {
+    result = gpr_inf_past(type);
+  } else if (us >= 0) {
+    result.tv_sec = us / 1000000;
+    result.tv_nsec = (int32_t)((us - result.tv_sec * 1000000) * 1000);
+  } else {
+    /* Calculation carefully formulated to avoid any possible under/overflow. */
+    result.tv_sec = (-(999999 - (us + 1000000)) / 1000000) - 1;
+    result.tv_nsec = (int32_t)((us - result.tv_sec * 1000000) * 1000);
+  }
+  return result;
+}
+
+gpr_timespec gpr_time_from_millis(int64_t ms, gpr_clock_type type) {
+  gpr_timespec result;
+  result.clock_type = type;
+  if (ms == INT64_MAX) {
+    result = gpr_inf_future(type);
+  } else if (ms == INT64_MIN) {
+    result = gpr_inf_past(type);
+  } else if (ms >= 0) {
+    result.tv_sec = ms / 1000;
+    result.tv_nsec = (int32_t)((ms - result.tv_sec * 1000) * 1000000);
+  } else {
+    /* Calculation carefully formulated to avoid any possible under/overflow. */
+    result.tv_sec = (-(999 - (ms + 1000)) / 1000) - 1;
+    result.tv_nsec = (int32_t)((ms - result.tv_sec * 1000) * 1000000);
+  }
+  return result;
+}
+
+gpr_timespec gpr_time_from_seconds(int64_t s, gpr_clock_type type) {
+  gpr_timespec result;
+  result.clock_type = type;
+  if (s == INT64_MAX) {
+    result = gpr_inf_future(type);
+  } else if (s == INT64_MIN) {
+    result = gpr_inf_past(type);
+  } else {
+    result.tv_sec = s;
+    result.tv_nsec = 0;
+  }
+  return result;
+}
+
+gpr_timespec gpr_time_from_minutes(int64_t m, gpr_clock_type type) {
+  gpr_timespec result;
+  result.clock_type = type;
+  if (m >= INT64_MAX / 60) {
+    result = gpr_inf_future(type);
+  } else if (m <= INT64_MIN / 60) {
+    result = gpr_inf_past(type);
+  } else {
+    result.tv_sec = m * 60;
+    result.tv_nsec = 0;
+  }
+  return result;
+}
+
+gpr_timespec gpr_time_from_hours(int64_t h, gpr_clock_type type) {
+  gpr_timespec result;
+  result.clock_type = type;
+  if (h >= INT64_MAX / 3600) {
+    result = gpr_inf_future(type);
+  } else if (h <= INT64_MIN / 3600) {
+    result = gpr_inf_past(type);
+  } else {
+    result.tv_sec = h * 3600;
+    result.tv_nsec = 0;
+  }
+  return result;
+}
+
+gpr_timespec gpr_time_add(gpr_timespec a, gpr_timespec b) {
+  gpr_timespec sum;
+  int64_t inc = 0;
+  GPR_ASSERT(b.clock_type == GPR_TIMESPAN);
+  sum.clock_type = a.clock_type;
+  sum.tv_nsec = a.tv_nsec + b.tv_nsec;
+  if (sum.tv_nsec >= GPR_NS_PER_SEC) {
+    sum.tv_nsec -= GPR_NS_PER_SEC;
+    inc++;
+  }
+  if (a.tv_sec == INT64_MAX || a.tv_sec == INT64_MIN) {
+    sum = a;
+  } else if (b.tv_sec == INT64_MAX ||
+             (b.tv_sec >= 0 && a.tv_sec >= INT64_MAX - b.tv_sec)) {
+    sum = gpr_inf_future(sum.clock_type);
+  } else if (b.tv_sec == INT64_MIN ||
+             (b.tv_sec <= 0 && a.tv_sec <= INT64_MIN - b.tv_sec)) {
+    sum = gpr_inf_past(sum.clock_type);
+  } else {
+    sum.tv_sec = a.tv_sec + b.tv_sec;
+    if (inc != 0 && sum.tv_sec == INT64_MAX - 1) {
+      sum = gpr_inf_future(sum.clock_type);
+    } else {
+      sum.tv_sec += inc;
+    }
+  }
+  return sum;
+}
+
+gpr_timespec gpr_time_sub(gpr_timespec a, gpr_timespec b) {
+  gpr_timespec diff;
+  int64_t dec = 0;
+  if (b.clock_type == GPR_TIMESPAN) {
+    diff.clock_type = a.clock_type;
+  } else {
+    GPR_ASSERT(a.clock_type == b.clock_type);
+    diff.clock_type = GPR_TIMESPAN;
+  }
+  diff.tv_nsec = a.tv_nsec - b.tv_nsec;
+  if (diff.tv_nsec < 0) {
+    diff.tv_nsec += GPR_NS_PER_SEC;
+    dec++;
+  }
+  if (a.tv_sec == INT64_MAX || a.tv_sec == INT64_MIN) {
+    diff = a;
+  } else if (b.tv_sec == INT64_MIN ||
+             (b.tv_sec <= 0 && a.tv_sec >= INT64_MAX + b.tv_sec)) {
+    diff = gpr_inf_future(GPR_CLOCK_REALTIME);
+  } else if (b.tv_sec == INT64_MAX ||
+             (b.tv_sec >= 0 && a.tv_sec <= INT64_MIN + b.tv_sec)) {
+    diff = gpr_inf_past(GPR_CLOCK_REALTIME);
+  } else {
+    diff.tv_sec = a.tv_sec - b.tv_sec;
+    if (dec != 0 && diff.tv_sec == INT64_MIN + 1) {
+      diff = gpr_inf_past(GPR_CLOCK_REALTIME);
+    } else {
+      diff.tv_sec -= dec;
+    }
+  }
+  return diff;
+}
+
+int gpr_time_similar(gpr_timespec a, gpr_timespec b, gpr_timespec threshold) {
+  int cmp_ab;
+
+  GPR_ASSERT(a.clock_type == b.clock_type);
+  GPR_ASSERT(threshold.clock_type == GPR_TIMESPAN);
+
+  cmp_ab = gpr_time_cmp(a, b);
+  if (cmp_ab == 0) return 1;
+  if (cmp_ab < 0) {
+    return gpr_time_cmp(gpr_time_sub(b, a), threshold) <= 0;
+  } else {
+    return gpr_time_cmp(gpr_time_sub(a, b), threshold) <= 0;
+  }
+}
+
+int32_t gpr_time_to_millis(gpr_timespec t) {
+  if (t.tv_sec >= 2147483) {
+    if (t.tv_sec == 2147483 && t.tv_nsec < 648 * GPR_NS_PER_MS) {
+      return 2147483 * GPR_MS_PER_SEC + t.tv_nsec / GPR_NS_PER_MS;
+    }
+    return 2147483647;
+  } else if (t.tv_sec <= -2147483) {
+    /* TODO(ctiller): correct handling here (it's so far in the past do we
+       care?) */
+    return -2147483647;
+  } else {
+    return (int32_t)(t.tv_sec * GPR_MS_PER_SEC + t.tv_nsec / GPR_NS_PER_MS);
+  }
+}
+
+double gpr_timespec_to_micros(gpr_timespec t) {
+  return (double)t.tv_sec * GPR_US_PER_SEC + t.tv_nsec * 1e-3;
+}
+
+gpr_timespec gpr_convert_clock_type(gpr_timespec t, gpr_clock_type clock_type) {
+  if (t.clock_type == clock_type) {
+    return t;
+  }
+
+  if (t.tv_nsec == 0) {
+    if (t.tv_sec == INT64_MAX) {
+      t.clock_type = clock_type;
+      return t;
+    }
+    if (t.tv_sec == INT64_MIN) {
+      t.clock_type = clock_type;
+      return t;
+    }
+  }
+
+  if (clock_type == GPR_TIMESPAN) {
+    return gpr_time_sub(t, gpr_now(t.clock_type));
+  }
+
+  if (t.clock_type == GPR_TIMESPAN) {
+    return gpr_time_add(gpr_now(clock_type), t);
+  }
+
+  return gpr_time_add(gpr_now(clock_type),
+                      gpr_time_sub(t, gpr_now(t.clock_type)));
+}