Support for wildcard queries

Provides support for persistent wildcard file requests, as described in
#96
Also moved CanonicalizePath into common code (poly::fs)

src/poly/fs.cc

@@ -0,0 +1,194 @@
+/**
+ ******************************************************************************
+ * Xenia : Xbox 360 Emulator Research Project                                 *
+ ******************************************************************************
+ * Copyright 2015 Ben Vanik. All rights reserved.                             *
+ * Released under the BSD license - see LICENSE in the root for more details. *
+ ******************************************************************************
+ */
+
+#include "poly/fs.h"
+
+#include <string>
+#include <vector>
+#include <algorithm>
+
+namespace poly {
+namespace fs {
+
+std::string CanonicalizePath(const std::string& original_path) {
+  char path_separator('\\');
+  std::string path(poly::fix_path_separators(original_path, path_separator));
+
+  std::vector<std::string::size_type> path_breaks;
+
+  std::string::size_type pos(path.find_first_of(path_separator));
+  std::string::size_type pos_n(std::string::npos);
+
+  while (pos != std::string::npos) {
+    if ((pos_n = path.find_first_of(path_separator, pos + 1)) == std::string::npos) {
+      pos_n = path.size();
+    }
+
+    auto diff(pos_n - pos);
+    switch (diff)
+    {
+    case 0:
+      pos_n = std::string::npos;
+      break;
+    case 1:
+      // Duplicate separators
+      path.erase(pos, 1);
+      pos_n -= 1;
+      break;
+    case 2:
+      // Potential marker for current directory
+      if (path[pos + 1] == '.') {
+        path.erase(pos, 2);
+        pos_n -= 2;
+      }
+      else {
+        path_breaks.push_back(pos);
+      }
+      break;
+    case 3:
+      // Potential marker for parent directory
+      if (path[pos + 1] == '.' && path[pos + 2] == '.'){
+        if (path_breaks.empty()) {
+          // Ensure we don't override the device name
+          std::string::size_type loc(path.find_first_of(':'));
+          auto req(pos + 3);
+          if (loc == std::string::npos || loc > req) {
+            path.erase(0, req);
+            pos_n -= req;
+          }
+          else {
+            path.erase(loc + 1, req - (loc + 1));
+            pos_n -= req - (loc + 1);
+          }
+        }
+        else {
+          auto last(path_breaks.back());
+          auto last_diff((pos + 3) - last);
+          path.erase(last, last_diff);
+          pos_n = last;
+          // Also remove path reference
+          path_breaks.erase(path_breaks.end() - 1);
+        }
+      }
+      else {
+        path_breaks.push_back(pos);
+      }
+      break;
+
+    default:
+      path_breaks.push_back(pos);
+      break;
+    }
+
+    pos = pos_n;
+  }
+
+  // Remove trailing seperator
+  if (!path.empty() && path.back() == path_separator) {
+    path.erase(path.size() - 1);
+  }
+
+  // Final sanity check for dead paths
+  if ((path.size() == 1 && (path[0] == '.' || path[0] == path_separator))
+    || (path.size() == 2 && path[0] == '.' && path[1] == '.')) {
+    return "";
+  }
+
+  return path;
+}
+
+WildcardFlags WildcardFlags::FIRST(true, false);
+WildcardFlags WildcardFlags::LAST(false, true);
+
+WildcardFlags::WildcardFlags()
+  : FromStart(false)
+  , ToEnd(false)
+  , WithCase(false)
+{ }
+
+WildcardFlags::WildcardFlags(bool start, bool end)
+  : FromStart(start)
+  , ToEnd(end)
+  , WithCase(false)
+{ }
+
+WildcardRule::WildcardRule(std::string str_match, const WildcardFlags &flags)
+  : match(str_match)
+  , rules(flags)
+{ }
+
+bool WildcardRule::Check(std::string& str) const
+{
+  if( match.empty() ) {
+    return true;
+  }
+
+  if( str.size() < match.size() ) {
+    return false;
+  }
+
+  std::string::size_type result(str.find(match));
+
+  if( result != std::string::npos ) {
+    if( rules.FromStart && result != 0 ) {
+      return false;
+    }
+
+    if( rules.ToEnd && result != ( ( str.size() -1 ) - match.size() ) ) {
+      return false;
+    }
+
+    str.erase(0, result + match.size());
+    return true;
+  }
+
+  return false;
+}
+
+void WildcardEngine::PreparePattern(const std::string &pattern)
+{
+  rules.clear();
+
+  WildcardFlags flags(WildcardFlags::FIRST);
+  size_t n = 0;
+  size_t last = 0;
+  while ((n = pattern.find_first_of('*', last)) != pattern.npos) {
+    if (last != n) {
+      std::string str_str(pattern.substr(last, n - last));
+      rules.push_back(WildcardRule(str_str, flags));
+    }
+    last = n + 1;
+    flags = WildcardFlags();
+  }
+  if (last != pattern.size()) {
+    std::string str_str(pattern.substr(last));
+    rules.push_back(WildcardRule(str_str, WildcardFlags::LAST));
+  }
+}
+
+void WildcardEngine::SetRule(const std::string &pattern)
+{
+  PreparePattern(pattern);
+}
+
+bool WildcardEngine::Match(const std::string &str) const
+{
+  std::string str_copy(str);
+
+  for (const auto& rule : rules) {
+    if (!(rule.Check(str_copy))) {
+      return false;
+    }
+  }
+
+  return true;
+}
+
+}  // namespace fs
+}  // namespace poly

src/poly/fs.h

@@ -15,6 +15,9 @@
 #include "poly/config.h"
 #include "poly/string.h"
 
+#include <vector>
+#include <iterator>
+
 namespace poly {
 namespace fs {
 
@@ -35,6 +38,44 @@ struct FileInfo {
 };
 std::vector<FileInfo> ListFiles(const std::wstring& path);
 
+std::string CanonicalizePath(const std::string& original_path);
+
+class WildcardFlags
+{
+public:
+    bool
+      FromStart: 1,
+      ToEnd : 1,
+      WithCase : 1; // Unused for now
+
+    WildcardFlags();
+    WildcardFlags(bool start, bool end);
+
+    static WildcardFlags FIRST;
+    static WildcardFlags LAST;
+};
+
+class WildcardRule
+{
+public:
+    WildcardRule(std::string str_match, const WildcardFlags &flags);
+    bool Check(std::string& str) const;
+  
+private:
+  std::string match;
+    WildcardFlags rules;
+};
+
+class WildcardEngine
+{
+public:
+  void SetRule(const std::string &pattern);
+  bool Match(const std::string &str) const;
+private:
+  std::vector<WildcardRule> rules;
+  void PreparePattern(const std::string &pattern);
+};
+
 }  // namespace fs
 }  // namespace poly
 

src/poly/sources.gypi

@@ -9,6 +9,7 @@
     'config.h',
     'cxx_compat.h',
     'fs.h',
+    'fs.cc',
     'logging.cc',
     'logging.h',
     'main.h',