Move path and filesystem from build2 to libbutl

1 files changed, 256 insertions, 0 deletions

diff --git a/butl/path.txx b/butl/path.txx
new file mode 100644
index 0000000..6d418ff
--- /dev/null
+++ b/butl/path.txx
@@ -0,0 +1,256 @@
+// file      : butl/path.txx -*- C++ -*-
+// copyright : Copyright (c) 2014-2015 Code Synthesis Ltd
+// license   : MIT; see accompanying LICENSE file
+
+#include <vector>
+
+namespace butl
+{
+  template <typename C, typename K>
+  basic_path<C, K> basic_path<C, K>::
+  leaf () const
+  {
+    size_type p (traits::rfind_separator (this->path_));
+
+    return p != string_type::npos
+      ? basic_path (this->path_.c_str () + p + 1, this->path_.size () - p - 1)
+      : *this;
+  }
+
+  template <typename C, typename K>
+  typename basic_path<C, K>::dir_type basic_path<C, K>::
+  directory () const
+  {
+    if (root ())
+      return dir_type ();
+
+    size_type p (traits::rfind_separator (this->path_));
+
+    // Include the trailing slash so that we get correct behavior
+    // if directory is root.
+    //
+    return p != string_type::npos
+      ? dir_type (this->path_.c_str (), p + 1)
+      : dir_type ();
+  }
+
+#ifdef _WIN32
+  template <typename C, typename K>
+  typename basic_path<C, K>::string_type basic_path<C, K>::
+  posix_string () const
+  {
+    if (absolute ())
+      throw invalid_basic_path<C> (this->path_);
+
+    string_type r (this->path_);
+
+    // Translate Windows-style separators to the POSIX ones.
+    //
+    for (size_type i (0), n (r.size ()); i != n; ++i)
+      if (r[i] == '\\')
+        r[i] = '/';
+
+    return r;
+  }
+#endif
+
+  template <typename C, typename K>
+  basic_path<C, K>& basic_path<C, K>::
+  operator/= (basic_path<C, K> const& r)
+  {
+    if (r.absolute () && !this->path_.empty ()) // Allow ('' / '/foo').
+      throw invalid_basic_path<C> (r.path_);
+
+    if (this->path_.empty () || r.path_.empty ())
+    {
+      this->path_ += r.path_;
+      return *this;
+    }
+
+    if (!traits::is_separator (this->path_[this->path_.size () - 1]))
+      this->path_ += traits::directory_separator;
+
+    this->path_ += r.path_;
+    return *this;
+  }
+
+  template <typename C, typename K>
+  basic_path<C, K> basic_path<C, K>::
+  leaf (basic_path<C, K> const& d) const
+  {
+    size_type n (d.path_.size ());
+
+    if (n == 0)
+      return *this;
+
+    if (!sub (d))
+      throw invalid_basic_path<C> (this->path_);
+
+    size_type m (this->path_.size ());
+
+    if (n != m
+#ifndef _WIN32
+        && !d.root ()
+#endif
+    )
+      n++; // Skip the directory separator (unless it is POSIX root).
+
+    return basic_path (this->path_.c_str () + n, m - n);
+  }
+
+  template <typename C, typename K>
+  typename basic_path<C, K>::dir_type basic_path<C, K>::
+  directory (basic_path<C, K> const& l) const
+  {
+    size_type n (l.path_.size ());
+
+    if (n == 0)
+      return dir_type (this->path_);
+
+    if (!sup (l))
+      throw invalid_basic_path<C> (this->path_);
+
+    size_type m (this->path_.size ());
+
+    if (n != m)
+      n++; // Skip the directory separator.
+
+    return dir_type (this->path_.c_str (), m - n);
+  }
+
+  template <typename C, typename K>
+  basic_path<C, K> basic_path<C, K>::
+  relative (basic_path<C, K> d) const
+  {
+    basic_path r;
+
+    for (;; d = d.directory ())
+    {
+      if (sub (d))
+        break;
+
+      r /= basic_path ("..");
+
+      // Roots of the paths do not match.
+      //
+      if (d.root ())
+        throw invalid_basic_path<C> (this->path_);
+    }
+
+    return r / leaf (d);
+  }
+
+  template <typename C, typename K>
+  basic_path<C, K>& basic_path<C, K>::
+  normalize ()
+  {
+    if (empty ())
+      return *this;
+
+    bool abs (absolute ());
+
+    typedef std::vector<string_type> paths;
+    paths ps;
+
+    for (size_type b (0), e (traits::find_separator (this->path_)),
+           n (this->path_.size ());;
+         e = traits::find_separator (this->path_, b))
+    {
+      string_type s (this->path_, b, e == string_type::npos ? e : e - b);
+      ps.push_back (s);
+
+      if (e == string_type::npos)
+        break;
+
+      ++e;
+
+      while (e < n && traits::is_separator (this->path_[e]))
+        ++e;
+
+      if (e == n)
+        break;
+
+      b = e;
+    }
+
+    // First collapse '.' and '..'.
+    //
+    paths r;
+
+    for (typename paths::const_iterator i (ps.begin ()), e (ps.end ());
+         i != e; ++i)
+    {
+      string_type const& s (*i);
+      size_type n (s.size ());
+
+      if (n == 1 && s[0] == '.')
+        continue;
+
+      if (n == 2 && s[0] == '.' && s[1] == '.')
+      {
+        // Pop the last directory from r unless it is '..'.
+        //
+        if (!r.empty ())
+        {
+          string_type const& s1 (r.back ());
+
+          if (!(s1.size () == 2 && s1[0] == '.' && s1[1] == '.'))
+          {
+            // Cannot go past the root directory.
+            //
+            if (abs && r.size () == 1)
+              throw invalid_basic_path<C> (this->path_);
+
+            r.pop_back ();
+            continue;
+          }
+        }
+      }
+
+      r.push_back (s);
+    }
+
+    // Reassemble the path.
+    //
+    string_type p;
+
+    for (typename paths::const_iterator i (r.begin ()), e (r.end ());
+         i != e;)
+    {
+      p += *i;
+
+      if (++i != e)
+        p += traits::directory_separator;
+    }
+
+    if (p.empty () && !r.empty ())
+      p += traits::directory_separator; // Root directory.
+
+    this->path_.swap (p);
+    return *this;
+  }
+
+  template <typename C, typename K>
+  void basic_path<C, K>::
+  current (basic_path const& p)
+  {
+    const string_type& s (p.string ());
+
+    if (s.empty ())
+      throw invalid_basic_path<char> (s);
+
+    traits::current (s);
+  }
+
+  template <typename C, typename K>
+  void basic_path<C, K>::
+  init ()
+  {
+    // Strip trailing slashes except for the case where the single
+    // slash represents the root directory.
+    //
+    size_type n (this->path_.size ());
+    for (; n > 1 && traits::is_separator (this->path_[n - 1]); --n) ;
+    this->path_.resize (n);
+  }
+}