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Diffstat (limited to 'indra/llvfs/lldiriterator.cpp')
| -rw-r--r-- | indra/llvfs/lldiriterator.cpp | 216 |
1 files changed, 216 insertions, 0 deletions
diff --git a/indra/llvfs/lldiriterator.cpp b/indra/llvfs/lldiriterator.cpp new file mode 100644 index 0000000000..25550321f0 --- /dev/null +++ b/indra/llvfs/lldiriterator.cpp @@ -0,0 +1,216 @@ +/** + * @file lldiriterator.cpp + * @brief Iterator through directory entries matching the search pattern. + * + * $LicenseInfo:firstyear=2010&license=viewerlgpl$ + * Second Life Viewer Source Code + * Copyright (C) 2010, Linden Research, Inc. + * + * This library is free software; you can redistribute it and/or + * modify it under the terms of the GNU Lesser General Public + * License as published by the Free Software Foundation; + * version 2.1 of the License only. + * + * This library is distributed in the hope that it will be useful, + * but WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU + * Lesser General Public License for more details. + * + * You should have received a copy of the GNU Lesser General Public + * License along with this library; if not, write to the Free Software + * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA + * + * Linden Research, Inc., 945 Battery Street, San Francisco, CA 94111 USA + * $/LicenseInfo$ + */ + +#include "lldiriterator.h" + +#include <boost/filesystem.hpp> +#include <boost/regex.hpp> + +namespace fs = boost::filesystem; + +static std::string glob_to_regex(const std::string& glob); + +class LLDirIterator::Impl +{ +public: + Impl(const std::string &dirname, const std::string &mask); + ~Impl(); + + bool next(std::string &fname); + +private: + boost::regex mFilterExp; + fs::directory_iterator mIter; + bool mIsValid; +}; + +LLDirIterator::Impl::Impl(const std::string &dirname, const std::string &mask) + : mIsValid(false) +{ + fs::path dir_path(dirname); + + // Check if path exists. + if (!fs::exists(dir_path)) + { + llwarns << "Invalid path: \"" << dir_path.string() << "\"" << llendl; + return; + } + + // Initialize the directory iterator for the given path. + try + { + mIter = fs::directory_iterator(dir_path); + } + catch (fs::basic_filesystem_error<fs::path>& e) + { + llerrs << e.what() << llendl; + return; + } + + // Convert the glob mask to a regular expression + std::string exp = glob_to_regex(mask); + + // Initialize boost::regex with the expression converted from + // the glob mask. + // An exception is thrown if the expression is not valid. + try + { + mFilterExp.assign(exp); + } + catch (boost::regex_error& e) + { + llerrs << "\"" << exp << "\" is not a valid regular expression: " + << e.what() << llendl; + return; + } + + mIsValid = true; +} + +LLDirIterator::Impl::~Impl() +{ +} + +bool LLDirIterator::Impl::next(std::string &fname) +{ + fname = ""; + + if (!mIsValid) + { + llwarns << "The iterator is not correctly initialized." << llendl; + return false; + } + + fs::directory_iterator end_itr; // default construction yields past-the-end + bool found = false; + while (mIter != end_itr && !found) + { + boost::smatch match; + std::string name = mIter->path().filename(); + if (found = boost::regex_match(name, match, mFilterExp)) + { + fname = name; + } + + ++mIter; + } + + return found; +} + +/** +Converts the incoming glob into a regex. This involves +converting incoming glob expressions to regex equivilents and +at the same time, escaping any regex meaningful characters which +do not have glob meaning, i.e. + .()+|^$ +in the input. +*/ +std::string glob_to_regex(const std::string& glob) +{ + std::string regex; + regex.reserve(glob.size()<<1); + S32 braces = 0; + bool escaped = false; + bool square_brace_open = false; + + for (std::string::const_iterator i = glob.begin(); i != glob.end(); ++i) + { + char c = *i; + + switch (c) + { + case '*': + if (glob.begin() == i) + { + regex+="[^.].*"; + } + else + { + regex+= escaped ? "*" : ".*"; + } + break; + case '?': + regex+= escaped ? '?' : '.'; + break; + case '{': + braces++; + regex+='('; + break; + case '}': + if (!braces) + { + llerrs << "glob_to_regex: Closing brace without an equivalent opening brace: " << glob << llendl; + } + + regex+=')'; + braces--; + break; + case ',': + regex+= braces ? '|' : c; + break; + case '!': + regex+= square_brace_open ? '^' : c; + break; + case '.': // This collection have different regex meaning + case '^': // and so need escaping. + case '(': + case ')': + case '+': + case '|': + case '$': + regex += '\\'; + default: + regex += c; + break; + } + + escaped = ('\\' == c); + square_brace_open = ('[' == c); + } + + if (braces) + { + llerrs << "glob_to_regex: Unterminated brace expression: " << glob << llendl; + } + + return regex; +} + +LLDirIterator::LLDirIterator(const std::string &dirname, const std::string &mask) +{ + mImpl = new Impl(dirname, mask); +} + +LLDirIterator::~LLDirIterator() +{ + delete mImpl; +} + +bool LLDirIterator::next(std::string &fname) +{ + return mImpl->next(fname); +} |