From 61377c582e0f2675baa5f5e6e30a35d1a4164b33 Mon Sep 17 00:00:00 2001 From: Karen Arutyunov Date: Mon, 1 May 2017 16:08:43 +0300 Subject: Add hxx extension for headers and lib prefix for library dir --- libbutl/prefix-map.hxx | 138 +++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 138 insertions(+) create mode 100644 libbutl/prefix-map.hxx (limited to 'libbutl/prefix-map.hxx') diff --git a/libbutl/prefix-map.hxx b/libbutl/prefix-map.hxx new file mode 100644 index 0000000..0404f72 --- /dev/null +++ b/libbutl/prefix-map.hxx @@ -0,0 +1,138 @@ +// file : libbutl/prefix-map.hxx -*- C++ -*- +// copyright : Copyright (c) 2014-2017 Code Synthesis Ltd +// license : MIT; see accompanying LICENSE file + +#ifndef LIBBUTL_PREFIX_MAP_HXX +#define LIBBUTL_PREFIX_MAP_HXX + +#include +#include +#include // move() +#include // min() + +namespace butl +{ + // A map of hierarchical "paths", e.g., 'foo.bar' or 'foo/bar' with + // the ability to retrieve a range of entries that have a specific + // prefix. The '.' and '/' above are the delimiter characters. + // + // Note that as a special rule, the default implementation of + // compare_prefix treats empty key as everyone's prefix even if + // the paths don't start with the delimiter (useful to represent + // a "root path"). + // + // Implementation-wise, the idea is to pretend that each key ends + // with the delimiter. This way we automatically avoid matching + // 'foobar' as having a prefix 'foo'. + // + template + struct compare_prefix; + + template + struct compare_prefix> + { + typedef std::basic_string K; + + typedef C delimiter_type; + typedef typename K::size_type size_type; + typedef typename K::traits_type traits_type; + + explicit + compare_prefix (delimiter_type d): d_ (d) {} + + bool + operator() (const K& x, const K& y) const + { + return compare (x.c_str (), x.size (), y.c_str (), y.size ()) < 0; + } + + bool + prefix (const K& p, const K& k) const + { + size_type pn (p.size ()), kn (k.size ()); + return pn == 0 || // Empty key is always a prefix. + (pn <= kn && + compare (p.c_str (), pn, k.c_str (), pn == kn ? pn : pn + 1) == 0); + } + + protected: + int + compare (const C* x, size_type xn, + const C* y, size_type yn) const + { + size_type n (std::min (xn, yn)); + int r (traits_type::compare (x, y, n)); + + if (r == 0) + { + // Pretend there is the delimiter characters at the end of the + // shorter string. + // + char xc (xn > n ? x[n] : (xn++, d_)); + char yc (yn > n ? y[n] : (yn++, d_)); + r = traits_type::compare (&xc, &yc, 1); + + // If we are still equal, then compare the lengths. + // + if (r == 0) + r = (xn == yn ? 0 : (xn < yn ? -1 : 1)); + } + + return r; + } + + private: + delimiter_type d_; + }; + + template + struct prefix_map_common: M + { + typedef M map_type; + typedef typename map_type::key_type key_type; + typedef typename map_type::value_type value_type; + typedef typename map_type::key_compare compare_type; + typedef typename compare_type::delimiter_type delimiter_type; + + typedef typename map_type::iterator iterator; + typedef typename map_type::const_iterator const_iterator; + + explicit + prefix_map_common (delimiter_type d) + : map_type (compare_type (d)) {} + + prefix_map_common (std::initializer_list i, delimiter_type d) + : map_type (std::move (i), compare_type (d)) {} + + std::pair + find_prefix (const key_type&); + + std::pair + find_prefix (const key_type&) const; + }; + + template ::delimiter_type D> + struct prefix_map_impl: prefix_map_common + { + typedef typename prefix_map_common::value_type value_type; + + prefix_map_impl (): prefix_map_common (D) {} + prefix_map_impl (std::initializer_list i) + : prefix_map_common (std::move (i), D) {} + }; + + template ::delimiter_type D> + using prefix_map = prefix_map_impl>, D>; + + template ::delimiter_type D> + using prefix_multimap = + prefix_map_impl>, D>; +} + +#include + +#endif // LIBBUTL_PREFIX_MAP_HXX -- cgit v1.1