From 985e8f5f28da87be779b80942577f088321024af Mon Sep 17 00:00:00 2001
From: Boris Kolpackov <boris@codesynthesis.com>
Date: Fri, 5 Dec 2014 13:26:29 +0200
Subject: Add support for starting processes, getting file timestamps

g++-4.9 -std=c++11 -I.. -o bd bd.cxx process.cxx timestamp.cxx
---
 build/timestamp.cxx | 154 ++++++++++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 154 insertions(+)
 create mode 100644 build/timestamp.cxx

(limited to 'build/timestamp.cxx')

diff --git a/build/timestamp.cxx b/build/timestamp.cxx
new file mode 100644
index 0000000..db8efb2
--- /dev/null
+++ b/build/timestamp.cxx
@@ -0,0 +1,154 @@
+// file      : build/timestamp.cxx -*- C++ -*-
+// copyright : Copyright (c) 2014-2015 Code Synthesis Tools CC
+// license   : MIT; see accompanying LICENSE file
+
+#include <build/timestamp>
+
+#include <unistd.h>    // stat
+#include <sys/types.h> // stat
+#include <sys/stat.h>  // stat
+
+#include <time.h> // localtime, gmtime, strftime
+
+#include <ostream>
+#include <system_error>
+
+using namespace std;
+
+namespace build
+{
+  // Figuring out whether we have the nanoseconds in some form.
+  //
+  template <typename S>
+  constexpr auto nsec (const S* s) -> decltype(s->st_mtim.tv_nsec)
+  {
+    return s->st_mtim.tv_nsec; // POSIX (GNU/Linux, Solaris).
+  }
+
+  template <typename S>
+  constexpr auto nsec (const S* s) -> decltype(s->st_mtimespec.tv_nsec)
+  {
+    return s->st_mtimespec.tv_nsec; // MacOS X.
+  }
+
+  template <typename S>
+  constexpr auto nsec (const S* s) -> decltype(s->st_mtime_n)
+  {
+    return s->st_mtime_n; // AIX 5.2 and later.
+  }
+
+  template <typename S>
+  constexpr int nsec (...) {return 0;}
+
+  timestamp
+  path_timestamp (const std::string& p)
+  {
+    struct stat s;
+    if (stat (p.c_str (), &s) != 0)
+    {
+      if (errno == ENOENT || errno == ENOTDIR)
+        return timestamp_nonexistent;
+      else
+        throw system_error (errno, system_category ());
+    }
+
+    return system_clock::from_time_t (s.st_mtime) +
+      chrono::duration_cast<duration> (
+        chrono::nanoseconds (nsec<struct stat> (&s)));
+  }
+
+  ostream&
+  operator<< (ostream& os, timestamp ts)
+  {
+    // @@ replace with put_time()
+    //
+
+    time_t t (system_clock::to_time_t (ts));
+
+    if (t == 0)
+      return os << "<nonexistent>";
+
+    std::tm tm;
+    if (localtime_r (&t, &tm) == nullptr)
+      throw system_error (errno, system_category ());
+
+    // If year is greater than 9999, we will overflow.
+    //
+    char buf[20]; // YYYY-MM-DD HH:MM:SS\0
+    if (strftime (buf, sizeof (buf), "%Y-%m-%d %H:%M:%S", &tm) == 0)
+      return os << "<beyond year 9999>";
+
+    os << buf;
+
+    using namespace chrono;
+
+    timestamp sec (system_clock::from_time_t (t));
+    nanoseconds ns (duration_cast<nanoseconds> (ts - sec));
+
+    if (ns != nanoseconds::zero ())
+    {
+      os << '.';
+      os.width (9);
+      os.fill ('0');
+      os << ns.count ();
+    }
+
+    return os;
+  }
+
+  ostream&
+  operator<< (ostream& os, duration d)
+  {
+    // @@ replace with put_time()
+    //
+
+    timestamp ts; // Epoch.
+    ts += d;
+
+    time_t t (system_clock::to_time_t (ts));
+
+    const char* fmt (nullptr);
+    if (t >= 365 * 12 * 24 * 60 * 60)
+      fmt = "%Y-%m-%d %H:%M:%S";
+    else if (t >= 12 * 24 * 60* 60)
+      fmt = "%m-%d %H:%M:%S";
+    else if (t >= 24 * 60* 60)
+      fmt = "%d %H:%M:%S";
+    else if (t >= 60 * 60)
+      fmt = "%H:%M:%S";
+    else if (t >= 60)
+      fmt = "%M:%S";
+    else if (t >= 1)
+      fmt = "%S";
+
+    if (fmt != nullptr)
+    {
+      std::tm tm;
+      if (gmtime_r (&t, &tm) == nullptr)
+        throw system_error (errno, system_category ());
+
+      char buf[20]; // YYYY-MM-DD HH:MM:SS\0
+      if (strftime (buf, sizeof (buf), fmt, &tm) == 0)
+        return os << "<beyond 9999 years>";
+
+      os << buf;
+    }
+
+    using namespace chrono;
+
+    timestamp sec (system_clock::from_time_t (t));
+    nanoseconds ns (duration_cast<nanoseconds> (ts - sec));
+
+    if (ns != nanoseconds::zero ())
+    {
+      os << '.';
+      os.width (9);
+      os.fill ('0');
+      os << ns.count ();
+    }
+    else if (fmt == 0)
+      os << '0';
+
+    return os;
+  }
+}
-- 
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