Merge commit '4ebe6417a5fce5f0994fc0c31bebf732be96a07c' as 'boost'

boost/libs/filesystem/src/unique_path.cpp

@@ -0,0 +1,163 @@
+//  filesystem unique_path.cpp  --------------------------------------------------------//
+
+//  Copyright Beman Dawes 2010
+
+//  Distributed under the Boost Software License, Version 1.0.
+//  See http://www.boost.org/LICENSE_1_0.txt
+
+//  Library home page: http://www.boost.org/libs/filesystem
+
+//--------------------------------------------------------------------------------------// 
+
+// define BOOST_FILESYSTEM_SOURCE so that <boost/filesystem/config.hpp> knows
+// the library is being built (possibly exporting rather than importing code)
+#define BOOST_FILESYSTEM_SOURCE 
+
+#ifndef BOOST_SYSTEM_NO_DEPRECATED 
+# define BOOST_SYSTEM_NO_DEPRECATED
+#endif
+
+#include <boost/filesystem/operations.hpp>
+#include <cassert>
+
+# ifdef BOOST_POSIX_API
+#   include <fcntl.h>
+#   ifdef BOOST_HAS_UNISTD_H
+#      include <unistd.h>
+#   endif
+# else // BOOST_WINDOWS_API
+#   include <windows.h>
+#   include <wincrypt.h>
+#   ifdef _MSC_VER
+#      pragma comment(lib, "Advapi32.lib")
+#   endif
+# endif
+
+namespace {
+
+void fail(int err, boost::system::error_code* ec)
+{
+  if (ec == 0)
+    BOOST_FILESYSTEM_THROW( boost::system::system_error(err,
+      boost::system::system_category(),
+      "boost::filesystem::unique_path"));
+
+  ec->assign(err, boost::system::system_category());
+  return;
+}
+
+#ifdef BOOST_WINDOWS_API
+
+int acquire_crypt_handle(HCRYPTPROV& handle)
+{
+  if (::CryptAcquireContextW(&handle, 0, 0, PROV_RSA_FULL, CRYPT_VERIFYCONTEXT | CRYPT_SILENT))
+    return 0;
+
+  int errval = ::GetLastError();
+  if (errval != NTE_BAD_KEYSET)
+    return errval;
+
+  if (::CryptAcquireContextW(&handle, 0, 0, PROV_RSA_FULL, CRYPT_NEWKEYSET | CRYPT_VERIFYCONTEXT | CRYPT_SILENT))
+    return 0;
+
+  errval = ::GetLastError();
+  // Another thread could have attempted to create the keyset at the same time.
+  if (errval != NTE_EXISTS)
+    return errval;
+
+  if (::CryptAcquireContextW(&handle, 0, 0, PROV_RSA_FULL, CRYPT_VERIFYCONTEXT | CRYPT_SILENT))
+    return 0;
+
+  return ::GetLastError();
+}
+
+#endif
+
+void system_crypt_random(void* buf, std::size_t len, boost::system::error_code* ec)
+{
+# ifdef BOOST_POSIX_API
+
+  int file = open("/dev/urandom", O_RDONLY);
+  if (file == -1)
+  {
+    file = open("/dev/random", O_RDONLY);
+    if (file == -1)
+    {
+      fail(errno, ec);
+      return;
+    }
+  }
+
+  size_t bytes_read = 0;
+  while (bytes_read < len)
+  {
+    ssize_t n = read(file, buf, len - bytes_read);
+    if (n == -1)
+    {
+      close(file);
+      fail(errno, ec);
+      return;
+    }
+    bytes_read += n;
+    buf = static_cast<char*>(buf) + n;
+  }
+
+  close(file);
+
+# else // BOOST_WINDOWS_API
+
+  HCRYPTPROV handle;
+  int errval = acquire_crypt_handle(handle);
+
+  if (!errval)
+  {
+    BOOL gen_ok = ::CryptGenRandom(handle, len, static_cast<unsigned char*>(buf));
+    if (!gen_ok)
+      errval = ::GetLastError();
+    ::CryptReleaseContext(handle, 0);
+  }
+
+  if (!errval) return;
+
+  fail(errval, ec);
+# endif
+}
+
+}  // unnamed namespace
+
+namespace boost { namespace filesystem { namespace detail {
+
+BOOST_FILESYSTEM_DECL
+path unique_path(const path& model, system::error_code* ec)
+{
+  std::wstring s (model.wstring());  // std::string ng for MBCS encoded POSIX
+  const wchar_t hex[] = L"0123456789abcdef";
+  char ran[] = "123456789abcdef";  // init to avoid clang static analyzer message
+                                   // see ticket #8954
+  assert(sizeof(ran) == 16);
+  const int max_nibbles = 2 * sizeof(ran);   // 4-bits per nibble
+
+  int nibbles_used = max_nibbles;
+  for(std::wstring::size_type i=0; i < s.size(); ++i)
+  {
+    if (s[i] == L'%')                        // digit request
+    {
+      if (nibbles_used == max_nibbles)
+      {
+        system_crypt_random(ran, sizeof(ran), ec);
+        if (ec != 0 && *ec)
+          return "";
+        nibbles_used = 0;
+      }
+      int c = ran[nibbles_used/2];
+      c >>= 4 * (nibbles_used++ & 1);  // if odd, shift right 1 nibble
+      s[i] = hex[c & 0xf];             // convert to hex digit and replace
+    }
+  }
+
+  if (ec != 0) ec->clear();
+
+  return s;
+}
+
+}}}