Store an array of separators alongside with the path string

diff --git a/source/fs/path.cpp b/source/fs/path.cpp
index b8b7c223043786cf6bef748262f1e2d7cf495756..93805277749d96ed35cccaa86ecd130774f9174e 100644 (file)
--- a/source/fs/path.cpp
+++ b/source/fs/path.cpp
@@ -53,10 +53,7 @@ unsigned Path::size() const
        if(path.size()==1 && path[0]==DIRSEP)
                return 1;
 
-       unsigned count = 1;
-       for(string::const_iterator i=path.begin(); i!=path.end(); ++i)
-               if(*i==DIRSEP) ++count;
-       return count;
+       return separators.size()+1;
 }
 
 bool Path::is_absolute() const
@@ -109,16 +106,26 @@ void Path::add_component(const string &comp)
        {
                // Replace the path with the root directory
 #ifdef WIN32
-               unsigned slash = path.find(DIRSEP);
+               string::size_type slash = (separators.empty() ? string::npos : separators.front());
                if(is_windows_drive(path.substr(0, slash)))
+               {
                        path = path.substr(0, 2);
+                       separators.clear();
+               }
                else
 #endif
-               path = comp;
+               {
+                       path = comp;
+                       separators.clear();
+                       separators.push_back(0);
+               }
        }
 #ifdef WIN32
        else if(is_windows_drive(comp))
+       {
                path = comp;
+               separators.clear();
+       }
 #endif
        else if(comp=="..")
        {
@@ -133,22 +140,21 @@ void Path::add_component(const string &comp)
 #endif
                else
                {
-                       string::size_type slash = path.rfind(DIRSEP);
-                       string::size_type start = (slash==string::npos ? 0 : slash+1);
+                       string::size_type start = (separators.empty() ? 0 : separators.back()+1);
                        if(!path.compare(start, string::npos, ".."))
                        {
                                // If the last component already is a .., add another
+                               separators.push_back(path.size());
                                path += DIRSEP;
                                path += comp;
                        }
-                       else if(slash==string::npos)
+                       else if(separators.empty())
                                path = ".";
                        else
                        {
-                               if(slash==0)
-                                       slash = 1;
                                // Otherwise, erase the last component
-                               path.erase(slash, string::npos);
+                               path.erase(separators.back(), string::npos);
+                               separators.pop_back();
                        }
                }
        }
@@ -157,7 +163,10 @@ void Path::add_component(const string &comp)
                if(comp!="." && path.empty())
                        path = ".";
                if(path.size()>1 || (path.size()==1 && path[0]!=DIRSEP))
+               {
+                       separators.push_back(path.size());
                        path += DIRSEP;
+               }
                path += comp;
        }
 }
@@ -210,71 +219,58 @@ bool Path::operator>(const Path &other) const
 #endif
 }
 
-Path::Iterator Path::begin() const
-{
-       return Iterator(*this);
-}
 
-Path::Iterator Path::end() const
-{
-       Iterator i(*this);
-       i.start = i.end = std::string::npos;
-       return i;
-}
-
-
-Path::Iterator::Iterator(const Path &p):
+Path::Iterator::Iterator(const Path &p, bool e):
        path(&p),
-       start(0)
-{
-       if(path->path.empty())
-               start = end = string::npos;
-       else if(path->path[0]==DIRSEP)
-               end = 1;
-#ifdef WIN32
-       else if(path->path.size()>2 && path->path[2]==DIRSEP && is_windows_drive(path->path.substr(0, 2)))
-               end = 2;
-#endif
-       else
-               end = path->path.find(DIRSEP);
-}
+       iter(e ? path->separators.end() : path->separators.begin()),
+       end(e || path->path.empty())
+{ }
 
 Path::Iterator &Path::Iterator::operator++()
 {
-       start = end;
-       if(start>=path->path.size())
-               return *this;
-       if(path->path[start]==DIRSEP)
-               ++start;
-       end = path->path.find(DIRSEP, start);
+       if(iter==path->separators.end())
+               end = true;
+       else
+       {
+               ++iter;
+               if(path->path.size()==1 && path->separators.size()==1)
+                       end = true;
+       }
        return *this;
 }
 
 Path::Iterator &Path::Iterator::operator--()
 {
-       if(start==0)
-               return *this;
-
-       end = start;
-       if(end>1 && end<path->path.size() && path->path[end]!=DIRSEP)
-               --end;
-
-       start = path->path.rfind(DIRSEP, end-1);
-       if(start==string::npos)
-               start = 0;
-       else if(start<end-1)
-               ++start;
-
+       if(end)
+       {
+               end = false;
+               if(path->path.size()==1 && path->separators.size()==1)
+                       --iter;
+       }
+       else if(iter!=path->separators.begin())
+               --iter;
        return *this;
 }
 
 string Path::Iterator::operator*() const
 {
-       if(start>=path->path.size())
-               return string();
-       if(start==end)
-               return string();
-       return path->path.substr(start, end-start);
+       if(end)
+               throw logic_error("Path::Iterator::operator*");
+
+       string::size_type start = 0;
+       if(iter!=path->separators.begin())
+       {
+               PositionArray::const_iterator prev = iter;
+               start = *--prev+1;
+       }
+
+       string::size_type slash = string::npos;
+       if(iter!=path->separators.end())
+               slash = *iter;
+
+       if(slash==0)
+               return path->path.substr(start, 1);
+       return path->path.substr(start, slash-start);
 }
 
 } // namespace FS

diff --git a/source/fs/path.h b/source/fs/path.h
index d515d7817031c1df3f98d0ad459c92a597b0dbcc..9bc93f6c003eab2db5a695c2a312c9b1db1fc4c8 100644 (file)
--- a/source/fs/path.h
+++ b/source/fs/path.h
@@ -3,6 +3,7 @@
 
 #include <ostream>
 #include <string>
+#include <vector>
 
 namespace Msp {
 namespace FS {
@@ -23,26 +24,32 @@ paths always begin with a single "." component or a sequence ".." components.
 */
 class Path
 {
+private:
+       typedef std::vector<std::string::size_type> PositionArray;
+
 public:
        class Iterator
        {
-               friend class Path;
-
        private:
                const Path *path;
-               std::string::size_type start, end;
+               PositionArray::const_iterator iter;
+               bool end;
 
-               Iterator(const Path &);
+               Iterator(const Path &, bool = false);
        public:
+               static Iterator at_begin(const Path &p) { return Iterator(p); }
+               static Iterator at_end(const Path &p) { return Iterator(p, true); }
+
                Iterator &operator++();
                Iterator &operator--();
                std::string operator*() const;
-               bool operator==(const Iterator &i) const { return (start==i.start && end==i.end); }
+               bool operator==(const Iterator &i) const { return (iter==i.iter && end==i.end); }
                bool operator!=(const Iterator &i) const { return !(*this==i); }
        };
 
 private:
        std::string path;
+       std::vector<std::string::size_type> separators;
 
 public:
        Path();
@@ -86,8 +93,8 @@ public:
        bool operator>=(const Path &other) const { return !(*this<other); }
        bool operator!=(const Path &other) const { return !(*this==other); }
 
-       Iterator begin() const;
-       Iterator end() const;
+       Iterator begin() const { return Iterator::at_begin(*this); }
+       Iterator end() const { return Iterator::at_end(*this); }
 };
 
 inline std::ostream &operator<<(std::ostream &o, const Path &p) { o<<p.str(); return o; }